Abstracts DGAV

s – DGCH Annual Congress 2019 – Munich, March 26–29 • DOI 10.1515/iss-2019-2001 s1 Innov Surg Sci 2019; 4, (Suppl 1): s1–s205

Bleeding complications are rare, but potentially life-threatening events in thyroid surgery (ca. 1,2 -1,8%). Theories about tracheal collapse dominated the literature over decades, but they were only based on case reports and small case series available in literature. We were able to collect some basic experimental data in our previous animal experiments about the underlying pathophysiology, especially the connection between cervical hemorrhage and mortality for respiratory failure and hypoxemia.
Our aim now was to investigate the clinical course and underlying pathophysiology of cervical hemorrhage in an animal model to derive clinical and therapeutical implications.

Materials and methods:
We induced 14 simulated and 6 spontaneous cervical hemorrhages in seven pigs with subsequent elevation of the cervical compartment pressure. The animals were under light general anesthesia with intact respiratory drive and secured airways. Vital signs, pressure levels in the cervical compartment, aorta, inferior vena cava, internal jugular vein, the cerebral oxygenation (INVOSTM) and the intracranial pressure were measured and analyzed.

Results:
Over all experiments, vital signs (arterial blood pressure, heart rate, peripheral oxygenation, intracranial pressure and CVP) were stable. In case of spontaneous cervical hemorrhage, cervical compartment pressures near the levels of the mean arterial blood pressure were detected (59mmHg). There was a direct correlation between the increase of the cervical compartment pressure and of the pressure elevation in the internal jugular vein in all experiments. In addition, there was a significant decrease of cerebral oxygenation following cervical compartment pressure elevation, which was independent of the systemic arterial oxygenation. In n = 9/14 (64%) of the experiments with simulated hemorrhage, we could induce respiratory failure due to the increase of cervical compartment pressure (threshold pressure 54mmHg). In these experiments, a significant decrease in cerebral oxygenation appeared about 120 seconds before respiratory failure.

Conclusion:
In case of spontaneous cervical hemorrhage pressure levels in the cervical compartment nearly reached the mean arterial blood pressure. There is a direct correlation between increase of cervical compartment pressure, increase of pressure in the internal jugular vein and decrease of cerebral oxygenation. Our investigations indicate an impairment of cerebral perfusion as a cause for respiratory failure based on the elevated cervical compartment pressure in cervical hemorrhage similar to other compartment syndromes. Abstracts -DGCH Annual Congress 2019-Munich, March 26-29 • DOI 10.1515/iss-2019-2001 s13 Innov Surg Sci 2019; 4, (Suppl 1): s1-s205 Major hepatic resection following radioembolization for neuroendocrine liver metastases is safe and associated with a prolonged hepatic tumor clearance (Abstract ID: 168)

Pathologie Oldenburg
Background: The BRAFV600E mutation (BRAF+) is the most common genetic cause of papillary thyroid carcinoma (PTC) and is considered a specific diagnostic marker. Studies suggest that the mutation status is associated with aggressive tumor characteristics such as extrathyroid extension and lymph node metastasis, thereby increasing the risk of persistent and recurrent progressions. It is therefore being discussed whether a more extensive surgical strategy should be pursued in the case of preoperative mutation detection in fine needle puncture. However, the importance of molecular diagnostics remains a controversial issue.

Materials and methods:
A retrospective study for the analysis of histological tissue in PTC from 2007-2016 was conducted, which investigated the extent to which BRAF+ in PTC was present in our own patient's population and the influence of positive mutation detection on various outcome parameters. N=270 patients from the database of the University Clinic for Visceral Surgery at Pius Hospital Oldenburg met the inclusion criteria. The consent for the evaluation of the resected tissue stored in the pathology Oldenburg was granted by n=198 Pat. The data was analyzed with regard to diagnostic procedures, pathological characteristics, therapeutic intervention and postoperative complications.

Results:
n=186 (m=46; w=140) tissue samples were successfully pyrosequenced with n=98 BRAF+ and n=88 BRAF-. There is no significant difference between BRAF+ and BRAF-in gender distribution, body mass index, thyroid scintigraphy, preoperative TSH, surgical therapy, radioiodine therapy, lymph node metastasis, distant metastasis, complicated courses and recurrence. Significant differences (BRAF+ vs. BRAF-) Fig 1). In a multivariate analysis, a model with lymph node metastasis with regards to number and localization, and BRAF mutation status best describes recurrence development (p<0.001), but the BRAF mutation status alone is not significant in this model.

Conclusion:
BRAF+ incidence in our collective is comparable to literature. The results suggest a connection of the BRAF mutation with more aggressive tumor characteristics, as evidenced for instance by extrathyroid extension and multifocal growth and simultaneously smaller tumor size, but a sole influence of BRAF+ on recurrence rate could not be proven. However, if a BRAF+ patient is treated surgically, one should take into account the seemingly more aggressive tumor behavior.

Universitätsklinikum Marburg
Background: Radical en-bloc resection of the tumor is generally recommended for parathyroid carcinoma (PC) as primary treatment strategy. However, it remains unclear, whether the removal of the ipsilateral thyroid lobe and central lymph nodes lead to a survival benefit. This study analysed the survival of PC after surgical treatment.

Materials and methods:
We retrospectively analysed patients with PC treated in our hospital regarding clinicopathological features, surgical treatments, disease-free and overall survival.

Results:
From 1977 to 2018 19 patients with PC were operated. At diagnosis 1 patient had distant metastases and 18 patients showed a local disease. Ten patients underwent initial en-bloc resection with hemithyroidectomy and ipsilateral lymphadenectomy and the other 9 patients received a parathyroidectomy or palliative resection. All patients with parathyroidectomy developed a recurrence (9/9) compared to only 2 of 10 with initial en-bloc resection. The 2 patients with en-bloc resection required 1 and 2 reoperations for recurrent disease compared to up to 16 reoperations/-interventions in the 9 patients with initial parathyroidectomy. After a median follow-up of 118 months (range, 60-305 months) the median disease-free survival time was with 92 months significantly longer after radical enbloc resection than after parathyroidectomy (32 months, p<0.05). At the time of analysis there was no difference in overall survival benefit between groups (132 vs. 107 months), which is most likely due to the high rate of reoperations and the use of mimpara in the parathyroidectomy group.

Conclusion:
If there is any clinical suspicion for PC, an en-bloc resection should be performed to provide a chance of long-term cure. Transoral (para-)thyroid surgery was first described by German study groups. Meanwhile and optimized Transoral Endoscopic Vestibular Approach (TOETVA) has been implemented by Anuwong. We report on our two years experiences, results of TOETVA in Austria and Germany and further development.

Materials and methods:
Since June 2017 37 TOETVA procedures and 3 transoral resections with an additional retroauricular access (TOVARA) to retrieve bulky thyroid specimens were performed in patient(s) with single thyroid nodules, sporadic primary hyperparathyroidism or thyroglossal duct cyst. TOETVA was performed using 3 laparoscopic ports, laparoscopic instruments and ultrasonic or bipolar devices inserted at the oral vestibule. Surgical outcome and complications were evaluated.

Results:
25 patients presented with solitary thyroid nodules, 12 had multinodular goitre with scintigraphic cold nodules and/or multifocal hyperfunctioning thyroid tissue, two patients suffered from sporadic primary hyperparathyroidism and one patient suffered from a thyroglossal duct cyst. In three patients the thyroid was removed via an additional retroauricular approach (Mean Volume:58ml+19ml). No conversion to open surgery was necessary. Average tumour size was 2.5cm. Temporary hoarseness occurred in two patients. No mental nerve injury occurred. Transient hypoparathyroidism was evident after successful parathyroidectomy and in one patient after thyroidectomy. 20 patients developed a slight postoperative chin hematoma. No infection occurred.

Conclusion:
TOETVA is feasible and safe. An additional retroauricular approach may be helpful to remove bulky thyroid specimen. The transoral approach shows promise for patients who are motivated to avoid a visible neck scar. After successful implementation in Austria and Germany further transoral operations are destined in selected patients. Adrenal metastases in malignant melanoma patients under additional therapy are often the only site of tumor progression. Aim of the study was to evaluate the outcome of adrenalectomy together with the adjuvant therapy.

Materials and methods:
In this study we retrospectively evaluated all consecutive patients between 2008 until 2018 with progressive adrenal metastases of malignant melanoma. Assessed were postoperative outcome parameters, overall survival, progression free survival and the type of adjuvant therapy.

Results:
We analyzed 23 patients (14 female) with a median age of 62 years . In two patients the adrenal gland was the only location of metastasis while 21 patients had multiple sites of metastases. 17 patients underwent a laparoscopic resection and six an open resection. There was no surgery associated postoperative complication or mortality registered. After a median follow up of 18 months  16 patients are still alive, 11 patients with complete remission or stable tumor disease, all of them with the adjuvant of an additional immunotherapy. In no patient a local recurrence developed in the site of adrenal resection.

Long-term Outcome of Surgical Resection in Gastroenteropancreatic Neuroendocrine
Neoplasias: Results from a German nation-wide multi-centric registry (Abstract ID: 749)

Background:
Neuroendocrine neoplasia (NEN) are rare and heterogenous. Clinical experience is difficult to acquire. The german NET-registry allows to study longterm outcome after surgical resection.

Materials and methods:
This is a retro-and prospectively collected analysis of patient data with gastroenteropancreatic NEN from the german NET-registry (1999NET-registry ( -2012 with limited disease (LD, stage I-IIIB).

Conclusion:
Surgical resection in NEN is associated with improved survival in LD. Complete histological tumor resection (R0) is the key issue for longterm survival. This is seen in excellent survival rates after 10 years, while the 5-ysr are similar for R0, R1 and R2 resection, possibly expressing the indolent nature of NEN . The rate of complete tumor-resection (R0) in LD is independent of tumor grading and comparable for both G1/G2 and G3-NEN. Multimodal approaches and neoadjuvant procedures should be focused on and further evaluated in order to reach this goal. Patients who are reasonable operative candidates with limited disease stage should be considered for resection Abstracts -DGCH Annual Congress 2019-Munich, March 26-29 • DOI 10.1515/iss-2019-2001s24 Innov Surg Sci 20194, (Suppl

RoMed Klinikum Rosenheim
Background: The intraoperative localization of hyperplastic parathyroid glands (PGs) has gained increasing importance in planning surgical strategy both in patients with hyperfunctioning uniglandular and multiglandular parathyroid disease. However, the identification of the parathyroid glands can be extremely challenging even for experienced surgeons, mainly because of the variability in number and anatomy. In this study we used indocyanine green fluorescence angiography for the intraoperative detection of pathologic parathyroid glands.

Materials and methods:
This is a retrospective analysis of prospectively collected data. Thirty-seven consecutive patients undergoing surgery for biochemically proven hyperparathyroidism between February 2016 and March 2018 at the University Hospital of Mannheim were eligible for enrolment. Prior to surgery, all patients underwent neck US, and 99mTc-MIBI for preoperative planning, except patients with pHPT due to a single parathyroid adenoma. Analysis was conducted to determine the sensitivity of three modalities (US, 99mTc-MIBI and ICGA). The factors associated with ICG uptake were also evaluated.

Results:
Overall 64 lesions were resected. Final histopathologic analysis confirmed the parathyroid origin of 62 of them (96,8%). Intraoperative ICG fluorescence imaging successfully identified 59 of 62 (95, 16%) parathyroid glands. In comparison, preoperative sonography scan could only localize 42 of 62 parathyroids (67,74%) whereas 99mTc-MIBI only identified 35 of the 62 parathyroids (56,45%). Variables as age, sex, preoperative calcium and PTH, size and US positivity were not associated with the ICG uptake. However, a positive MIBI of a parathyroid gland increased 5 times the probability of a positive intraoperative fluorescence angiography according to the univariate analysis.

Conclusion:
Our results demonstrated that ICG fluorescence imaging could easily localize PGs and lead to a high resection rate. The analysis revealed that the ICG uptake of PTGs was associated with MIBI positivity, and was especially useful when preoperative imaging techniques failed. Furthermore, this technique has shown to be useful to verify the perfusion of the remnant in patients undergoing subtotal parathyroidectomy, and to successfully identify PGs in re-operative neck surgery or in case of ectopic locations. In conclusion, intraoperative ICG fluorescence imaging has promising application prospects in real-time PG localization increasing the therapeutic efficacy. While most patients undergo either subtotal parathyroidectomy or total parathyreoidectomy with autotransplantation total parathyreoidectomy has been suggested as alternative treatment option in renal hyperparathyreoidism. Especially recurrence and reoperations hamper the benefit of leaving any parathyroid remnant. This might also lead to late complications like cardiovascular events or impaired kidney function after transplantation.

Materials and methods:
We retrospectively analyzed our single-institution results from our database between 1998 and 2018. All patients undergoing total or completion parathyroidectomy after persistence or recurrence were analyzed.

Results:
Between 2001 and 2015 we found 66 patients undergoing total parathyroidectomy (67 operations). 15 patients were operated for recurrence/persistence. Average parathormone (PTH) preoperatively was 858.3 ng/mL and dropped to 50.7 at discharge. Further on we saw that patients with PTH < 75 ng/mL at discharge remained stable within the normal range during longterm follow-up. Calcium was within the normal range preoperatively and during longterm follow-up, mostly due to adequate medication. 13 patients died during follow-up, 6 following infectious complications, 4 after cardiovascular events.

Conclusion:
Longterm results after total parathyreoidectomy revealed stable PTH-and calcium-levels after successful operation. Death from Cardiovascular events was comparable to patients with subtotal parathyroidectomy. This might even allow for successful kidney transplantation after total parathyreoidectomy.  Primary tumor resection in stage IV small intestinal neuroendocrine tumors (SI-NETs) is controversial. Thus, we evaluated the outcome of primary tumor resection at diagnosis in asymptomatic patients with SI-NETs and unresectable distant metastases.

Materials and methods:
Patients with stage IV SI-NETs without abdominal symptoms were selected from a prospective database of the ENETS Excellence Center Marburg treated between 1/2004 and 12/2017. Patients were divided in those who underwent primary tumor resection at diagnosis combined with oncologic treatment (PS group) and those who underwent nonsurgical treatment or delayed surgery as needed for symptoms combined with oncologic treatment (NS group). Overall survival (OS), reoperation rates measured from baseline as well as prognostic factors in the PS group were retrospectively evaluated.

Results:
The PS group included 114 patients (61 male, 53 female) with a median age of 60 years, the NS group 32 patients (19 male, 13 female) with a median age of 59 years. 11 (35%) patients of the NS group needed surgery for intestinal obstruction after median 59 (range 1 to 186) months. Overall, the median OS was not statistically different between the PS (37 months) and the NS groups (45months, p=0.29). A liver metastasis burden >50% was a strong negative prognostic factor in both goups with a median survival of 29 months compared to a median survival of 39 months in patients with <50% (p<0.01). The rate of operative procedures for intestinal obstruction after initial treatment was significantly lower in the PS group (7 of 114, 6%) compared to the NS group (11 of 32 35%, p<0.01). In the PS group a R2 resection of the primary and a liver metastasis burden >50% were significant negative prognostic factors (p<0.01), whereas age, gender, Ki67 index and lymph node ratio were not significantly associated with survival.

Conclusion:
In patients with asymptomatic stage IV SI-NET resection of the primary tumor seems to be only beneficial, if the liver metastasis burden is less than 50%. Abstracts -DGCH Annual Congress 2019-Munich, March 26-29 • DOI 10.1515/iss-2019-2001s27 Innov Surg Sci 20194, (Suppl

Universitätsklinikum Erlangen
Background: Gender differences in colorectal carcinoma (CRC) were examined with special interest in incidence, age at diagnosis, tumor site, surgical and multimodal treatment, postoperative complications, quality indicators and long-term prognosis.

Conclusion:
Gender-specific differences were found in various subgroups between men and women with CRC. The quality of treatment was very good in both sexes. Abstracts -DGCH Annual Congress 2019-Munich, March 26-29 • DOI 10.1515/iss-2019-2001

Background:
Incisional hernias of the abdominal wall are frequent complication after laparotomy (9-20%). Open incisional hernia repair with sublay mesh placement (SMP) on the posterior rectus sheath is described as being a sufficient method for repairing incisional hernia. In order to ensure wound healing and to therefore prevent recurrence, carrying an abdominal binder (AB) or a pressure dressing (PD) and physical rest for a certain time is the common postoperative recommendation, though the evidence for post-operative treatment is low. Hence, we conducted a survey to reveal the different recommendations given by surgical departments (SD).

Materials and methods:
We conducted a survey among 65 German SDs of the HELIOS Hospital Group. The SDs were interviewed about the number of open incisional hernia repair with SMP in the time frame of 2013-2014, the known recurrence rate (RR), their recommended prescription of the AB/PD and the time of physical rest.

Results:
The head physicians of 48 surgical departments answered the questionnaire. The survey revealed 42 different recommendations of postoperative-treatment. The majority of the SDs advices 4 weeks (20,5 %) of physical rest and no prescription of the AB (29,5 %). No correlation between the known RR and the duration of physical rest was detected. No head physician's prescribes a PD.

Conclusion:
Due to our findings we assume that a short period of physical rest is a considerable postoperative treatment following an open incisional hernia repair with SMP. By reducing the individual incapacity for work and immobility this would have a social-economic impact. The use of a PD may prevent seroma formation. Further investigations with randomised clinical trials are mandatory to support our hypothesis.

Universitätsklinikum Düsseldorf
Background: Prior lower abdominal surgery is generally considered as a relative contraindication for laparoscopic totally extraperitoneal (TEP) inguinal hernioplasty. We conducted a meta-analysis of studies comparing the feasibility and safety of TEP inguinal hernia repair between patients with (PS) and without history of lower abdominal surgery (NS).

Materials and methods:
A systematic literature search for studies comparing the outcome of TEP inguinal hernioplasty in patients with and without previous lower abdominal surgery was conducted. Data regarding postoperative outcomes were extracted and compared by meta-analysis. The Odds Ratio and Standardized Mean Differences with 95% Confidence Intervals (CI) were calculated.
For the secondary endpoints, conversion rate, peritoneal tears, major intraoperative bleeding, postoperative haematoseroma, operative time, anddelay in return to normal activities a statistically significant difference favoring the NS group was noted.

Conclusion:
Current evidence suggests that patients with previous lower abdominal surgery undergoing TEP inguinal hernia repair do not have the same benefits as those with no history of surgery. Inguinal hernia repair is one of the most frequently performed surgical procedures. Endoscopic techniques like TAPP and TEP have become standard of care together with the conventional open techniques. Especially in endoscopic inguinal hernia repair, there is a confusing amount of different meshes and fixation techniques with an impact on patients' perioperative and long-term outcome. We present the first single-center data on the use of titanized extra-lightweight meshes and fibrin glue fixation compared to staple fixation regarding long-term outcome, especially chronic pain.

Materials and methods:
A clinical trial with retrospective analysis of patient-and procedure-related data and prospective questionnaire-based follow-up (Herniamed) was conducted. 612 inguinal hernia repairs performed in a specialized hernia center in 501 patients were analyzed. A standard TAPP technique was used with placement of TiMesh extralight (16g/m2) and either fibrin glue or staple fixation. Procedure-and patient-related data are compared between groups with regard to perioperative complications and long-term outcome.

Results:
612 TAPP procedures were performed in 501 patients. Fibrin glue was used in 519 (85%) and staple fixation in 93 (15%) cases. There were significant differences between groups regarding the distribution of hernia size according to the EHS groin hernia classification (χ2; p=0.001), mesh size (p<0.001), duration of the surgical procedure (p<0.001), and pain on POD1 (p=0.024). No betweengroup differences were noted regarding perioperative complications such as seroma or hematoma formation and need for re-laparoscopy. During a mean follow-up of 30.85 ± 20.74 month with a followup rate of 80%, there was no difference in long-term outcome, especially for rate of recurrence (χ2; p=0.098) and development of chronic pain (χ2; p=0.985). The overall rate of recurrence was 2.8% (n=17), and in 2.1% of surgical cases (n=13; 2.1% vs. 2.2%) patients complained of chronic pain.

Conclusion:
Inguinal hernia repair using extra-lightweight titanized meshes and fibrin glue fixation is safe and feasible compared to staple fixation regarding the long-term outcomes recurrence and development of chronic pain. As expected, the rate of patients developing chronic pain was extremely low at 2.1%, independent of the type of fixation.

Universitätsklinikum Regensburg
Background: Incisional hernia developement following laparotomy represents one of the most frequent complications, with an incidence described in the literature of up to 13%. Mesh repair alone has shown recurrence rates as high as 36%. Commonly, hernia reconstruction with mesh repair results in persistent rectus diastasis. While component separation, as described by Ramirez, may achieve successful medialising of the rectus muscles, simultaneous weakening of abdominal wall integrity occurs. Our retrospective study describes a new method which enables the surgeon to anatomically and functionally reconstruct (recurrent) large incisional hernias without component separation and with preservation of abdominal wall layer integrity

Materials and methods:
Between 2013 -2018 a total of 17 patients with (recurrent) incisional hernias were operated on using the corset technique. In 6 cases (multiple) previous mesh repairs had failed. In 5 other patients resorbable mesh and split thickness skin grafts (STSG) had been applied for abdominal closure. In some of these patients previous non-resorbable mesh repair had been unsuccessful. The remaining 6 cases had not received mesh repair. Rectus diastasis in this patient series was measured 3-20 cm. Follow-up was 24 months.

Results:
The great majority of patients demonstrated very promising functional outcomes. Complete mid line union of rectus muscles was achieved in 15/17 cases (88%). Failure was seen in 2 desolate cases with persistent fistula. Recurrence rate of functional relevant hernia formation was seen in 3/17 patients (18%). A supplemental mesh implantation was used in 6/17 of cases. The corset technique successfully centralised the rectus muscles anatomically in the midline without persistent rectus diastasis. Prerequisites for successful reconstruction should include intact rectus abdominis muscles and strong sutures.

Conclusion:
The corset technique for incisional hernia repair achieves an anatomical recconstruction with adequate functional outcomes and relinquishment of component separation. Background Patients with symptomatic midline abdominal hernia (umbilical, infraumbilical, Port, and/or epigastric hernias) and concomitant rectus abdominis diastasis represent a growing clinical problem. The optimal management of this complex hernia situation is the subject of an ongoing debate in the literature.
This paper reports on the early results of an innovative surgical technique aimed at managing this hernia situation.
Aim To analyze feasibility and safety, in particular, early postoperative outcome characterized by morbidity (in particular, by intraoperative, specific and general complication rate) and mortality based on a unicenter observational study to reflect daily surgical practice in hernia surgery using a novel surgical approach such as LEESS.

Materials and methods:
Methods Laparoscopic Extraperitoneal Endoscopic Staple-based Sublay operation (LEESS) with mesh is a surgical technique recently known in the literature for its good outcome for midline hernia repair via transperitoneal route (Brazilian Technique) and Endoscopic Component Separation Techniques. The early postoperative outcome results for the first consecutive 50 patients are presented here in this systematic clinical unicenter observational study on quality assurance and reflecting daily surgical practice in a consecutive patient cohort (study design).

Results:
Results In 5 out of 50 (10 %), a symptomatic subfascial seroma was observed (minor complication). As a major complication, two patients (4 %) developed postoperative complications requiring redo surgery. These were two cases of internal herniation through a defect in the posterior rectus sheath, the herniated intestine was reduced and the defect was sutured laparoscopically. All other complications were successively managed with conservative treatment. During the mid-term postoperative course, i.e., after 11 months, 4 out of 50 (8 %) patients reported occasional pain, including pain at rest in one patient.

Conclusion:
Conclusion The LEESS technique with mesh augmentation is an innovative, minimally invasive, feasible and safe surgical procedure for treatment of patients with a complex abdominal wall hernia comprising symptomatic umbilical, port, and/or epigastric hernias with concomitant rectus abdominis diastasis. Abstracts -DGCH Annual Congress 2019-Munich, March 26-29 • DOI 10.1515/iss-2019-2001s34 Innov Surg Sci 20194, (Suppl 1): s1-s205 Picture: stapling rectus muscels with mesh in sublay space Abstracts -DGCH Annual Congress 2019-Munich, March 26-29 • DOI 10.1515/iss-2019-2001  The objective of this study was to demonstrate a new suturing technique in reference to fascia closure after laparotomy in an experimental setup to increase the tearing force of the fascia.

Materials and methods:
Two ordinary DIN A4 papers, which represents the fascia were sutured at the edges in a length of approx. 5 cm with the known continuous technique in the abdominal surgery and with the new technique, we called it: Spider suture. A bucket arranged on the interconnection was filled with sand until the sutures teared. Measuring the final weight of the bucket allowed comparing the carrying capacities of the paper of the two techniques.

Results:
A significant (Fisher's test, p=0.017) increase of mean carrying capacity from 1776.5g (classic continuous suture) to 5101.75g (basic Spider suture) was found. The carrying capacity of the paper was increased to 287% compared to the classic continuous suture.

Conclusion:
Spider suture could be an effective improvement in closure of the abdominal wall in abdominal surgery to minimize the risk of developing of incisional hernia. This method allows the surgeon to perform an abdominal closure adapted to the quality of patient's fascia. Further clinical studies will show the effectiveness of this method.

Background:
The management of abdominal hernias of > 15 cm diameter and the special case of the abdomen apertum with a large eventration, can be demanding. The purpose is the closure of the fascial defect and additional mesh reinforcement.

Materials and methods:
A 57 year old patient with abdominal hernia and evisceration was admitted for hernia repair after having undergone a large number (>14) of abdominal operations. These were for instance cholecystectomy, choledochojejunostomy, laparotomy with adhesiolysis at least four times, inflammation of the abdominal wall with numerous cycles of abdominal vacuum therapy, surgical treatment of several enterocutaneous fistulas and mesh grafts. All operations were performed between 1990 and 2017 resulting in an open abdomen only covered by mesh graft. The patient had already undergone one hernia repair with an onlay mesh one year before in another hospital. She was told that no further operations could be done. The CT scan showed the absence of the abdominal wall with a musculofascial defect of 22x24 cm.
After resection of the mesh graft and complex adhesiolysis, a total closure of the fascial defect was reached, restoring the abdominal wall anatomically without tension with non absorbable sutures. Component separation or relaxing incision of the fascia were not necessary. For reinforcement we used a 20x30 cm2 CICAT mesh in an onlay position. The mesh was fixed to the fascia with non absorbable sutures. A primary skin closure was reached with a relaxing skin incision on the left side of the lower abdomen.

Results:
While postoperative intensive care observation, the patient showed no symptoms of abdominal compartment or dyspnoea. The wound in the midline healed properly. Due to chronic pain and former opioid use in high doses, the patient received a peridural catheter. Transfusion of two erythrocyte concentrates was necessary. The patient could go back to the peripheral ward after 3 days. The wound of the left lower abdomen was treated with a pico vacuum therapy. The patient was discharged 10 days after the operation.

Conclusion:
Special treatment like compartment separation or relaxing incisions of the fascia to achieve a total closure of large musculofascial defects, which can cause further complications, is not always necessary for large abdominal hernias. Primary fascia closure with mesh enhancement is demanding, but often feasible. Since there are no guidelines for the surgical management of open abdomen, the indication for surgical management has to be taken individually.

Lukaskrankenhaus Neuss
Background: One oft he biggest problems in hernia surgery is, to get sufficient results in cases of hernias with big midline defects (W3 hernias) and/or "loss of domain" hernias.Even in cases of small defects, "loss of domain" can cause serious problems, since reposition of the hernia sac contents will result in an increased intraabdominal pressure with all its problems (compartment syndrome/respiratory failure etc) and too much tension on the reconstructed midline.To avoid dissection of healthy parts oft he abdominal wall like in the Ramirez operation, which we think is not the best option for multimorbide patients, we developed our own method of Botox supported abdominal wall reconstruction in IPOM technique, B.U.B.I

Materials and methods:
In this method we combine the Botox induced relaxation of the abdominal wall with the IPOM technique to achieve a full reconstruction oft he midline combined with a mesh. Inclusion Criteria were W3 and/or Loss of Domain Hernias. Exlusion Criteria were Pregnancy, Myasthenia, ALS, Breastfeeding, Urostoma and Enterostoma.2 weeks prior to surgery patients were treated with sonography guided Botox injection in both sides of the lateral abdominal wall muscles.To verify the result of the injection a low dose CT scan is done at the day before surgery.Intraoperative the size of the defect was documented.During the healing process of the midline and the ingrowth oft he mesh the Botox effect decreases 4-6 months until it is gone. During that period the abdominal cavity can get used to the situation slowly without causing any pressure related problems.

Results:
30 Patients have been treated with Botox injection so far and 28 of them have already been operated.
In 21 of 28 cases we could do a full reconstruction oft he midline (Defect sizes have been between 6x6 cm and 30x35 cm). In 7 cases we could at least reduce the defect. Mesh sizes have been between 20x30 cm to 28x37 cm.Intraoperatively no problems occured and postoperative we had 1 SISSI. Reoperation was not necessary. 22 patients already went through follow up after 6-12 months (clinical/CT scan) and are without a hernia recurrence so far.We havent seen any Botox related problems so far.

Conclusion:
As known reconstruction oft he abdominal wall is a challenge especially in W3 and/or "loss of domain" hernias.So far the Ramirez operation in all its variations (open, laparoscopic, laparoscopic assisted etc.) has been one of the most common procedures to gain more tissue for closing the midline defect.Even though this method can give 7-10 cm space per side in some cases, we think it is not the best solution.Especially in multimorbide older patients the high rate of wound complications is a serious problem.Avoiding these problems and preserving the healthy lateral parts oft he abdominal wall which are dissected for example in the Ramirez operation, B.U.B.I. is a chemical component seperation technique without any risk for the patient.Our patients show, that it s even possible to do a midline recontruction in huge hernias without creating any pressure related problems. As a positive side effect, Botox reduces the postoperative pain in the lateral abdominal wall.B.U.B.I. is a safe and

University Hospital Bern
Background: Inflammatory myofibroblastic tumors of the liver (IMTL) are extremly rare neoplasms and very little is known about their pathogenesis and etiology. Due to the intermediate biological behavior and the risk for local recurrence and metastases, surgical resection is usually recommended. Unfortunately, a preoperative diagnosis is extremely difficult to obtain and the definite diagnosis can often only be established post resection.

Materials and methods:
Retrospective Case report and review of the current literature of patients with IMTL.

Results:
We herein present a case of an otherwise healthy 32-year-old woman who presented with intermittent fever, unclear blood loss, malaise and right flank pain 4 months postpartum. Initial ultrasound examination found a liver mass in segment IVa/b of uncertain dignity, confirmed by further diagnostic work-up (CT / MR / PET-CT) that suggested an adenoma ( Figure). Immediate hepatic resection was performed achieving a negative resection margin and all clinical symptoms resolved. Histological analysis diagnosed the rare finding of an inflammatory myofibroblastic tumor of the liver and revealed cytoplasmic anaplastic lymphoma kinase (ALK) expression by immunohistochemistry ( Figure). A comprehensive review of the literature confirmed the rarity of this tumor entity in the liver, with only very few cases reported world-wide. Therefore, no diagnostic tools have been established so far and resection is usually recommended for unclear liver lesions.

Conclusion:
IMTLs are extremly rare and difficult to diagnose. Due to their intermediate biological behavior, surgical resection should be performed whenever feasible and patients should be followed-up in order to detect recurrence and metastasis as early as possible.
Picture: Figure: (1) IMTL imaging features: (A, asterisk) ultrasound image, (B) magnetic resonance imaging (MRI): homogeneous high signal in T2-weighted imaging (asterisk), (C) early enhancement in the arterial phase with hepatocyte specific contrast medium at the rim (arrow), (D) strong enhancement in the venous phase (arrow), (E) low intracellular uptake in the hepatobiliary phase after 20 minutes, (F) no clear diffusion restriction in the diffusion-weighted imaging (apparent diffusion coefficient, ADC).
(2) Postoperative macroscopic pathology of the IMTL (3) Histology of a well demarcated firm vascularized tumor mass with spotty inflammatory infiltrate, (A) at higher magnification bland proliferation of spindle cells in broad fascicles, (B) scattered lymphocytes and plasma cells and (C) intense positivity of the spindel cells for ALK Even though IgG4-related disease has gained increased attention worldwide, the diagnosis remains challenging. IgG4-related sclerosing cholangitis (IgG4-SC) is not well described in the western hemisphere and may mimic cholangiocarcinoma (CC), especially when occur-ring without other symptoms such as, e.g. concurrent pancreatitis or retroperitoneal fibrosis. We present a case to add further information to the diagnosis and treatment of this challenging disease.

Materials and methods:
A 60-year-old male patient presented with painless jaundice. Prior medical history showed diabetes mellitus type I, high blood pressure, and deep vein thrombosis. Diagnostic investigations were strongly suspicious of a Klatskin tumor, although biopsies were inconclusive. The tumor marker Carbohydrate Antigen 19-9 (CA 19-9) was elevated. Prior to the recommended surgery, the patient had two second opinions in two different university hospitals, both arguing for surgery as well.

Results:
The patient received hilar resection with right hemihepatectomy. During the postoperative course, some major complications occurred, i.e. recurrent pleural effusion, abscess in the liver resection area, sepsis, ileus, and restricted liver metabolism. Treatment with prednisolone did not show any improvement. Approximately 3 months after surgery, the patient died in consequence of acute respiratory failure. Histology showed no signs of CC, but IgG4-SC could be diagnosed.

Conclusion:
In the case of preoperative signs of CC, differential diagnosis of IgG4-SC needs to be considered, in particular, in cases with missing histologic proof of malignant disease.

Inselspital, Bern
Background: Minimal-invasive hepatectomy (MIH) has been increasingly performed for benign and malignant liver tumors with promising short-term results. However, the oncological results of MIH for the treatment of patients with colorectal liver metastases (CRLM) needs to be determined in order to allow widespread introduction of the technique.

Materials and methods:
Clinicopathological data of patients who underwent liver resection for CRLM between 2005 and 2017 at the Department of Surgery of the Charité Berlin were assessed. A validation cohort from the Inselspital Bern was additionally evaluated. Postoperative outcomes und long-term survival of patients following MIH were compared with those of patients undergoing conventional open hepatectomy (OH) after 1:1 propensity score matching.

Conclusion:
MIH for CLM is associated with lower postoperative morbidity and shorter length of hospital stay, resulting in oncologic outcomes comparable to those achieved with the established OH. Our findings suggest that MIH should be considered as the preferred method for the treatment of curatively resectable CLM.

Background:
Inhibition of vascular endothelial growth factor (VEGF) by bevacizumab as part of oxaliplatin-based chemotherapy in patients with colorectal liver metastases has shown protective effects against the development of Sinusoidal Obstruction Syndrome (SOS). Our aim was to evaluate the impact of an anti-VEGF treatment on SOS, liver regeneration and function after major hepatectomy in a murine model of oxaliplatin-induced SOS.

Materials and methods:
C57Bl/6 mice (n = 116) were treated with intraperitoneal oxaliplatin (Ox), oxaliplatin + anti-VEGF (OxAV), or glucose (Glu) over five weeks. One week after last treatment, mice were either sacrificed or subjected to major hepatectomy. Mice who underwent hepatectomy were sacrificed after 24, 36, 48 and 72 hours (n = 3 each), respectively. Liver tissue was used for the histological analysis of SOS. Plasma was collected for the analysis of alanine aminotransferase, aspartate aminotransferase, bilirubin, VEGF-A, hepatocyte growth factor (HGF) and plasminogen-activator inhibitor 1 (PAI-1). Liver regeneration was assessed by quantitative PCR for Ki-67 and immunohistochemistry for BrdU. Quantitative PCR was also performed to evaluate gene expression levels of VEGF-A, VEGF-R1 and VEGF-R2.

Conclusion:
Inhibition of VEGF protects against the development of SOS in a murine model of oxaliplatin-induced SOS and improves liver regeneration after major hepatectomy. PAI-1 and HGF may present other possible key factors in the pathogenesis of SOS development.

Background:
A 46-year-old female patient, with a prior medical history of abdominal pain, presented to us in 07/2017 with an incidental finding of a 1.8 x 2 cm mass adherent to the pancreatic head in the computed tomography (CT ). In the last years the patient suffered from diarrhea, nausea, recurrent epigastric abdominal pain and recently from progressive back pain. Three months prior to presentation in our department, the patient was diagnosed with pancreatic insufficiency with increased size of the pancreatic head in the abdominal sonography but without biochemical evidence of acute pancreatitis. Furthermore, she reported about a positive family history for colon and lung cancer. Further diagnostic workup revealed a normal CA 19-9 tumor marker (6 U/ml), and a cystic lesion with wall calcifications poorly demarcated from pancreatic head without evidence of malignancy or cystic adenoma in the endosonographic examination. Additional workup showed no evidence of autoimmune pancreatitis or neuroendocrine tumor.
The Magnetic resonance cholangiopancreatography (MRI) showed the prior described cystic pancreatic head mass without dilatation of the pancreatic duct. A CT guided biopsy of the mass was recommended by the tumor board and was histologically consistent with an inflammatory myofibroblastic tumor (IMT). Six months later, a follow up MRI showed a significant progression of the pancreatic lesion to 3.5 x 2.6 cm, so that a pylorus preserving pancreatic head resection (PPPD) was recommended by the interdisciplinary tumor board. The histologic examination of the resected mass showed a mesenchymal tumor of the pancreatic head (6.5x5.0x3.0 cm) with a spindle shaped cells with inflammatory components, prominent calcifications and very low proliferation activity which was consistent with IMT. Postoperatively, a biochemical leak was treated conservatively.

Conclusion:
IMT are rare mesenchymal tumors (incidence 0.04-0.7%) which can affect a variety of organs, mainly the lung and rarely the pancreas. Patients with IMT of the pancreas can present clinically with a wide variety of symptoms. However, those lesions are mostly discovered incidentally and can be mistaken with pancreatic cancer. Local tumor ablation plays an important role in the treatment of hepatocellular carcinoma (HCC) and is often used as bridging or downstaging for patients listed for transplantation. While image-guided navigation technology has recently entered the clinical setting, reports of large patient series are still rare.

Materials and methods:
Retrospective analysis of patients treated with stereotactic image-guided microwave ablation (SIMWA) for HCC at our institution between 01/2015 and 12/2017. Each intervention was performed using CTguidance with needle trajectory planning by landmark-based registration and an aiming device for precise needle placement. Patients were under general anesthesia with jet-ventilation to optimize registration accuracy.

Conclusion:
SIMWA is very safe and efficient for the treatment of HCC offering a curative treatment approach especially for otherwise inoperable or conventionally unablatable lesions by accurate and precise needle positioning in a minimally invasive setting. Objective: We aimed to determine the unbiased mortality rates for hepatobiliaryresections at the national level using hospital discharge dataof every inpatient case in Germany. In addition, we intended to examinethe effect of hospital volume on in-hospital mortality, and failure to rescue. Summary Background Data:Several studies have found strong volume-outcome relationships in highrisk surgery, with high mortality in low-volume facilities. However, there is a paucity of populationbased outcome data on hepatobiliary surgery in European countries, including Germany.

Materials and methods:
Methods: We studied all inpatient cases of hepatobiliary surgery (n = 31,114) in Germany from 2009 to 2015, using national hospital discharge data. Minor resections and major resections were examined separately. We evaluated the association between hospital volume and in-hospital mortality following major hepatobiliary resections by using multivariate regression methods. In addition, we analyzed rates the failure to rescue across hospital volume categories.

Results:
Results: Minor hepatobiliary resections were associated with an overall mortality rate of 3.9% and no significant volume-outcome effects. In contrast,overall mortality rate of major hepatobiliary resections was 10.3%. In this cohort, risk-adjusted in-hospital mortality following major resections varied widely across hospital volume categories, from 7.4% (95% CI 6.6-8.2) in very high volume hospitals to 11.4% (95% CI 10.4-12.5) in very low volume hospitals (OR 0.59, 95% CI 0.41-0.54). Moreover, rates of failure to rescue were lower in higher volume hospitals(eg, mortality in patients with at least one complication in very high volume hospitals: 36.2% vs. very low volume hospitals: 40.6%).

Conclusion:
Conclusions: In Germany, patients who undergo major hepatobiliary resections have improved outcomes if they are admitted to higher volume hospitals. Volume-outcome associations are not present in minor hepatobiliary surgery.

Universitätsklinikum Essen
Background: The volume effect in pancreatic surgery has gained increasing interest. Available Data for major pancreatic resections in Germany derived from hospital discharge data of every inpatient case lacking of relevant information like surgeon caseload and special surgical techniques.

Materials and methods:
In the framework of a prospective multicenter observational study data about pancreatic head resections from 27 German hospitals were collected from January 2006 to December 2009. We divided hospitals as well as surgeons into three volume groups. The aim was to analyze the effect of both hospital-and surgeon volume on postoperative outcome. Endpoints were mortality, length of hospital stay (LOS) and postoperative surgical complications with special regard to postoperative pancreatic fistula (POPF).

Results:
A total of 1.064 pancreatic head resection were performed. The overall postoperative mortality was 5.0% while the postoperative morbidity was 34.5%. There were no differences in mortality between the volume groups. Patients treated in high-volume hospitals showed a significant lower incidence of postoperative overall-(p=0.001) and specific surgical complications(p=0.021). Patients treated by high-volume surgeons had a significant lower incidence of POPF (p=0.001) and shorter LOS (p=0.007).

Conclusion:
Results support the request for centralization of pancreatic surgery and emphasize the importance of surgeon expertise.

Background:
Thermal ablation has proven beneficial for hepatocellular carcinoma and, within clinical trials, for colorectal liver metastases (CRLM). Ablation could be an interesting option for other secondary liver malignancies. In addition, computer-assisted navigation techniques have been introduced to increase efficacy and broaden the indications for this minimally invasive approach. The aim of our study was to evaluate short-term clinical outcome of patients undergoing percutaneous stereotactic image-guided microwave ablation (SIMWA) for liver metastases (excluding CRLM).

Materials and methods:
Retrospective study including all patients undergoing SIMWA for non-CRLM liver metastases in our institution between January 2015 and December 2017. All patients were recommended for SIMWA according to a multidisciplinary tumorboard decision. Follow-up consisted of 3-monthly clinical and radiological (CT scan or MRI) check-ups, with additional oncological follow-up as needed. End-points included local recurrence rate, overall and liver-specific disease progression and post-interventional complications.

Results:
We included 23 patients, the majority were men (56.5%), with a mean age of 58.4 years. Twenty-five interventions were performed to treat 40 lesions. These included seventeen neuroendocrine and nine breast cancer metastases, four sarcomas, two non-small cell lung cancers, three duodenal adenocarcinomas, one esophageal adenocarcinoma, one pancreatic adenocarcinoma, one ampullary carcinoma, one prostate carcinoma, and one renal cell carcinoma metastases. Incomplete ablation rate was 2.5% (1/40) and local recurrence rate 10% (4/40). Three patients (12%) presented with minor complications, no major complications were observed. Median follow-up was 15 months (range 2-32).
Overall disease progression occurred in 73.9% of patients with a median disease-free survival of 7 months (range 0-26). Overall survival was 18 months (range 2-39).

Conclusion:
SIMWA is a technically feasible, minimally invasive and safe treatment option for liver metastases of non-colorectal origin in selected patients. While it might offer an alternative to resection or a purely palliative strategy, the overall oncological benefit and effect on survival needs to be evaluated in a larger patient cohort.

Background:
Various approaches have been described for the reconstruction of the portal vein, superior mesenteric vein and the inferior vena cava. We present the use of the recanalized umbilical vein in various settings including transplantation, major liver resection and pancreatic surgery.

Materials and methods:
We retrospectively analyzed 4 cases, in which a recanalized umbilical vein was used for vascular reconstruction. The graft harvesting, size of the graft, technique of application, short-term results of vascular patency were studied.

Results:
A recanalized vein was successfully harvested in all patients with 5cm (median, range 3-7 cm) in length and 1.3 cm (median, range 1.0-1.8 cm) in width. The preparation of the recanalized umbilical vein was technically feasible and took no more than five minutes in each patient. All grafts were used as a patch for venous reconstruction. In 3 cases the graft was used for reconstruction of the portal vein and the superior mesenteric vein. In one patient, the graft was used to repair a large defect of the inferior vena cava. All vascular reconstructions were considered as successful as no bleeding or thrombosis was observed postoperatively.

Conclusion:
The recanalized umbilical vein is a reliable native autologous graft, which could be harvested in every patient with an intact ligament teres hepatis. We found that it is feasible to use this graft as a patch for the reconstruction of the inferior vena cava, the portal vein and the superior mesenteric vein. While the importance of lymphadenectomy (LNE) is well established for patients with pancreatic cancer, the direct impact of LNE in relation to other predictive factors is ill-defined. We aimed to determine the relative effect of LNE on overall survival (OS).

Materials and methods:
The National Cancer Data Base from the United States from 2004-2014 was queried for patients with resected pancreatic adenocarcinoma (stage IA-IIB). Patients were dichotomized to lymph node (LN) yield of 1-14 or >=15 LNs based on prior studies on optimal LN surveillance. We performed Joinpoint regression to assess optimal LN yield, covariance-balanced propensity score analyses to assess LN yield as a continuous measure, and mediation analysis to measure the degree of effect of LNE.

Results:
A total of 22,910 patients were included, mean age was 65.5 years (SD: 10.5), 48.2% were female. Mean LN yield was 16.1 (SD: 9.3), 11,399 (49.8%) had 1-14 LN and 11,511 (50.2%) had >=15 LN retrieved. Likelihood of LN positivity increased by 3.9% per LN up 8 examined LN, and by 0.7% per LN above 8. Five-year OS was 16.8%. After multivariable adjustment, OS was better in the >=15 LNs group (HR 0.91, CI: 0.88-0.94, p<0.001). On a continuous scale, survival improved with increasing number of LNs collected, even when stratified by tumor stage. Mediation analysis revealed that LNE had 14.3% direct effect on improved OS, while 26.9% of the effect was due to treatment at highvolume hospitals and 31.3% due to chemotherapy.

Conclusion:
Higher LN yield leads to increased positive LN retrieval, which translates directly into survival benefit across all tumor stages. However, the direct effect on OS is more influenced by chemotherapy and treatment at high-volume centers than by LNE.

Background:
In line with convincing results at international liver centers, the meaning of minimal-invasive techniques in complex liver surgery grew in Germany in recent years. Here, we report on our single center experiences with laparoscopic liver surgery.

Materials and methods:
We analyzed data of all consecutive patients undergoing laparoscopic liver surgery at the Department of Surgery, Charité -Universitätsmedizin Berlin between 02/2012 and 09/2018 with regard to patient characteristics, indications, complexity of procedures and postoperative outcomes.

Results:
In the last 6.5 years we performed 350 laparoscopic liver resections at our department. An annual increase of ~ 20 operations allows us to carry out > 120 liver resections per year fully laparoscopically. After initial careful patient selection, the patients' health and performance status has significantly worsened over time and is now considered representative. Malignant tumors represent the most common indication for laparoscopic liver resection with hepatocellular carcinoma and colorectal liver metastases accounting for ~ 60%.The percentage of complex procedures, e.g. resection of >= 3 segments or lesions in posterosuperior segments, increased significantly over time. Nevertheless, we were able to lower the rate of major complications (Dindo-Clavien > 3) below 13%.

Conclusion:
With growing experience less patient selection is evident in terms of patient characteristics, indications, and complexity of operations. Due to favorable postoperative results minimally invasive techniques have become firmly established even for complex procedures at our center.

Background:
Minimally invasive techniques have increasingly found their way into complex liver surgery in recent years. However, experience with laparoscopic hepatectomy for intrahepatic cholangiocarcinoma (iCC) is anecdotal to technical challenges, e.g. radical hilar lymphadenectomy.

Materials and methods:
Here we report on a 45-year old female patient diagnosed with a large intrahepatic cholangiocarcinoma (iCC) in the left liver lobe (diameter 10cm). We show a 4K video of an anatomical left hemihepatectomy (segments 2-4) with radical hilar lymphadectomy.

Results:
After exclusion of peritoneal spread, we performed an anatomical left hemihepatectomy in classical multiport technique. An ultrasound shear was used for superficial parenchym dissection. Deeper transection was performed under pringle maneuver using the waterjet technique. Both the left bile duct and the left vein were transected by using staplers. Radical hilar lymphadenectomy down the hepatic artery to the celiac trunk was performed fully laparoscopically according to established rules of open oncological surgery. No intraoperative transfusion of red blood cell concentrates was necessary. Operative time was 314 minutes. ICU stay was one day. Wound tubes could be removed on POD 2. No complications occurred postoperatively. The patient was discharged at POD 7. Microscopically tumor-free margins were confirmed histopathologically.

Conclusion:
We here present a video demonstrating our technique of fully laparoscopic left hemihepatectomy with radical hilar lympadencetomy for a iCC. Minimal-invasive hepatectomy should be considered a safe alternative to conventional open surgery even for iCC. Secondary lymphoid organs (SLO) are involved in induction and enhancement of anti-tumor immune responses on different tumor entities. Recent evidence suggests that anti-tumor immune responses may also be induced or enhanced in the tumor microenvironment in so called tertiary lymphoid structures (TLS). It is assumed that TLSrepresent a hotspot for T cell priming, B cell activation, and differentiation, leading to cellular and humoral anti-tumor immune response.

Materials and methods:
FFPE-slides of 50 primary PDAC patients were immunohistochemically (IHC) stained for CD20, CD3, CD8, AID, HLA-ABC and FoxP3 to analyze spatial distribution of tumor-infiltrating lymphocytes. 5-color immunofluorescence staining was performed to further investigate structural components of TLS in comparison to lymphoid follicles in SLOs. Microscope-based laser microdissection and Nanostring were used to compare gene expression in PDAC, TLS, SLOs and normal pancreatic tissue.

Results:
TLS were frequently detected in PDAC and were mainly localized along the invasive tumor margin. Results of TLS will be correlated with clinical parameters, immunoscore and immune escape mechanisms. 5-color Immunofluorescence staining revealed similar organization and function of TLS and SLO. Finally, gene expression analyzed by Nanostring revealed largely overlapping expression patterns in TLS and SLO.

Conclusion:
The results clearly demonstrate the close relationship of SLO and TLS regarding composition, function and gene expression.

Background:
In recent years, minimally invasive surgical approaches have gained an increasingly important role in hepatobiliary surgery. The aim of this study is to investigate the safety and potential benefits of laparoscopic liver resection (LLR) compared to open liver resection (OLR) for benign liver tumors and lesions.

Materials and methods:
Between January 2009 and December 2017, 182 patients underwent liver surgery for benign liver tumors and lesions in our center. After exclusion of 15 patients, the remaining 167 patients were divided into LLR group (n=54) and OLR group (n=113) and were compared with regard to perioperative outcomes. To overcome selection bias, a 1:1 propensity score matching (PSM) was performed. Additionally, patients undergoing major hepatectomy were divided into Major-LLR and Major-OLR groups and perioperative outcomes evaluated.

Conclusion:
Our case-matched study demonstrates shorter ICU and hospital stay using laparoscopic techniques while maintaining high-quality perioperative outcomes. Based on our findings, we suggest preferring the LLR over OLR for benign liver tumors and lesions regardless of the resection extent

Background:
The number of patients with acute pancreatitis (AP) is increasing in the world.Approximately 85% of patients with AP have a mild course of the disease. Nutritional support isan important factor in the treatment of these patients. However, the optimal timetable forrestoring oral intake is almost not studied. The aim of this study was to determinate the possibility of early recovery of oral nutrition in patients with mild AP.

Materials and methods:
We examined 51 patients with mild acute pancreatitis. In 25 patients,an early oral refeeding (EORF) was used when patients experienced hunger, and 26 patientsreceived routine oral refeeding (RORF) after pain disappeared and normalized pancreaticenzymes serum levels.

Results:
Age, sexual, etiological and laboratory parameters, the severity of the condition ofpatients in the two groups during hospitalization were not statistically different. Before startingthe diet in the EORF group, serum concentrations of pancreatic amylase and lipase wereelevated. There was a significant difference in the duration of the hunger strike afterhospitalization between the EORF group and the RORF group. In addition, there was asignificant decrease in the total number of days of hospitalization in the EORF group comparedwith the group RORF. There were no differences in the relapse of abdominal pain, abdominaldistension, elevated serum levels of pancreatic enzymes, and severity of the condition of patientsbetween these two groups. All patients who developed relapse of pain and transient abdominaldistension did not require a change in nutrition regimen. The activity of inflammation at theconcentration of C-reactive protein significantly earlier was leveled in patients from the group ofEORF. All patients were discharged according to standardized criteria.

Conclusion:
In patients with mild AP, early onset of oral refeeding, which is safe, promotes afaster reduction of the inflammatory process, reduces the timing of hospitalization.

Background:
Steatosis hepatis could influence the outcome after liver resection. The standard diagnostic tool is still a liver biopsy, but fatty liver could also be quantified by imaging procedures such as ultrasound and CT and recently MRI. However, even liver biopsy can produce different results, so-called sample bias, due to localization of the sample. Therefore 'chemical shift imaging' (CSI) using MRI can assess different areas of the liver parenchyma to analyze the fat fraction (FF). The aim of this work is the evaluation and comparison of the FF in the right and left liver lobe (LL) by CSI-MRI in a surgical patient collective.

Materials and methods:
In this retrospective study 39 patients underwent major or minor liver resection (n = 21 vs. n = 18) were examined for the FF in CSI-MRI imaging (time period 2016 -2017). The FF was measured separately in the right and left LL (Seg. V/VI vs. Seg. II/III) and evaluated by different possible CSI-MRI sequences (mDixon_Quandt, In-Phase/Opposed-Phase).

Results:
The mean FF of both LL was 4.21 % (n=39). In the right liver (Seg. V/VI) the FF was 3.86% vs 4.55 % in the left liver (Seg. II/III). The difference between the two LL is 0.69 %. Altogether a steatosis hepatis grade 1 (5 -33 %) was shown in the right LL in 38.5 % (15/39) and in the left LL in 35.9 % (14/39). In 12.8 % (5/39) a different grade of steatosis hepatis was found for the respective LL. Excluding patients with HCC due to a pre-existing steatosis or fibrosis, the difference between right and left liver was 16.7 % .(4/24) of the examinations. In this group, 25% (6/24) of the patients had grade 1 fatty liver in both LL. Considering only patient with liver metastasis the difference in FF between right and left LL was 30.8% (4/13) and 7.7 % (1/13) had grade 1 fatty liver in the right and left LL. Mean serum bilirubin on post-op day 5 was 0.78 mg/dl and 0.85 mg/dl excluding HCC patients.

Conclusion:
CSI-MRT imaging shows differences in preoperative fat fraction between the right and the left liver lobe. These differences have an effect on the classification of the local steatosis hepatis. Localized preoperative FF measure by CSI-MRI adds information on the future liver remnant and volume possible to resect and should be further evaluated in liver resection planning.

Uniklinik München
Background: In patients with pancreatic ductal adenocarcinoma (PDAC), the tumor microenvironment consists of cellular and stromal components that influence prognosis. Hence, tumor-infiltrating leukocytes (TILs) may predict prognosis more precisely than conventional staging systems. Studies on this impact of TILs are heterogeneous and further research is needed. Therefore, this study aims to point out the importance of peritumoral TILs and immune subtype classification in PDAC.

Materials and methods:
Material from 57 patients was analyzed with immunohistochemistry performed for CD3, CD8, CD20, CD66b, α-sma, and collagen. Hot spots with peritumoral TILs were quantified according to the QTiS algorithm and the distance of TILs hot spots to the tumor front was measured. Results were correlated with overall and progression-free survival.

Results:
High infiltration of peritumoral hot spots with CD3+, CD8+, and CD20+ TILs correlated significantly with improved overall (OS) and progression-free survival (PFS). Combined immune cell subtypes predicted improved OS, PFS. High infiltration of CD3+ TILs predict progression after 12 months. The location of TILs' hot spots and their distance to the tumor front may play a role in patients' survival.

Conclusion:
Peritumoral TILs and the stromal composition predict OS and PFS in PDAC.

Klinikum Stuttgart
Background: Irreversible electroporation (IRE) is emerging as treatment option for primary locally advanced pancreatic ductal adenocarcinoma (PDAC). Additionally, an increasing amount of data points towards efficacy of re-resection of local recurrence after resection of PDAC. We sought to investigate the feasibility and safety of IRE for the treatment of recurrence of PDAC.

Materials and methods:
We screened the records of patients prospectively followed in our single institution database who underwent IRE for locally unresectable either primary or recurrent PDAC. IRE was performed during surgical exploration for cases in which no metastases were present and the tumor was deemed locally unresectable. Endpoints were overall complication rate, death, reoperation/reintervention, pancreatitis, vascular complications (pseudoaneurysm, hepatic arterial thrombosis, and mesenteric/portal vein thrombosis), pancreatic fistula, ascites (>200 ml past pod3 or on imaging without fistula), biliary/hepatic complications, hemorrhage, intestinal perforations, SSI, timing of removal of surgical drains, length of ICU stay, length of hospital stay, emergency visits or readmission within 30 days.

Conclusion:
IRE for recurrence of PDAC was not more prone to intra-nor postoperative complications than in primary PDAC and can be considered a novel viable option for the treatment of local recurrence of PDAC. Mid-and long-term follow up of patients as well as randomized treatment studies are required to establish the definitive role of IRE in recurrence of PDAC.

Polyganics BV, Groningen
Background: Up to 10-15% of the patients develop a bile-leakage after liver surgery, which increases the length of hospital stay and overall mortality and morbidity. However, with no effective preventive measure at hand, the surgical community is forced to accept bile-leakage as an unavoidable post-surgery complication. To overcome this clinical challenge we developed a new tissue sealant patch to prevent postoperative bile-leakage.

Materials and methods:
The tissue sealant patch was developed in a multi angle approach including in-vitro comparison on tensile, burst pressure measurements and testing in a liver perfusion model with clinically relevant competitors. For in-vivo evaluation a porcine bile-leakage model was established and the tissue sealant patch was investigated in a prospective randomized animal trial with a suturing group and Veriset® group as controls.

Results:
More than 30 different prototypes were screened in-vitro. The final selected sealant prototype showed superiority compared to clinical used competitors Tachosil, Hemopatch and Veriset in tensile and burst pressure testing (p<0.05 each). Moreover, the newly developed patch reduced the leakage rate in the liver perfusion model (p<0.05). The pre-clinical performance of the sealant patch was confirmed in a porcine bile-leakage model. 21 animals were included in the study and randomized for treatment with the sealant, Verisetäor suturing (n=7 each). After 7 days incidence of bile leakage was significantly lower in the sealant group compared to the Veriset group (p<0.05) and comparable to the suturing control group. These promising results were supported by strong bile containment and the formation of a smooth fibrous capsule by the sealant within one week. This was paralleled by the formation of neo bile ducts. Furthermore, no systemic or local side effects (e.g. bilioma) were seen.

Conclusion:
The new designed sealant was as effective as suturing in preventing bile-leakage in our animal model. This was due to strong bile containment and formation of a fibrous capsule by the sealant within one week. The efficacy of the sealant was also histologically proven, as formation of neo bile ducts -which indicates a biliary obstruction -was detected. More importantly, no clinical relevant side effect of the sealant became evident. To our knowledge, this is the first report of a randomized trial showing the efficacy of a tissue sealant device for preventing postoperative bile leakage.

Background:
Postoperative pancreatic fistula (POPF) is the Achilles heel of pancreatic surgery. Pancreatic texture, as assessed by the surgeon, has been identified as the strongest predictor of POPF in many studies. However, texture is a subjective parameter with no proven reliability or internal or external validity. Therefore a more objective parameter is needed for exact risk stratification in pancreatic surgery. The aim was to evaluate fibrosis at the pancreatic cut margin as an alternative parameter.

Materials and methods:
The RECOPANC trial was conducted as a monitored multicenter prospective trial. Pancreatic fibrosis was assessed retrospectively from H&E stained tissue slides of the pancreatic cut margin collected centrally during conduct of the RECOPANC trial. Fibrosis was graded from 0 (no fibrosis) to III (severe fibrosis). Predictive value of fibrosis grade and pancreatic texture with regard to POPF of grade B/C was assessed by univariable and multivariable statistical modeling in R software.

Results:
Fibrosis grading showed strong interrater reliability (kappa=0.74) and correlated positively with hard pancreatic texture (p<0.05). In univariable analysis, area under the curve (AUC) for the prediction of POPF B/C was higher for fibrosis grade than for pancreatic texture (0.71 vs 0.59). In multivariable analysis, the following predictors were selected by elastic net regression: sex, surgeon volume, main pancreatic duct diameter and fibrosis. The final multivariable model reached an AUC of 0.78 with PPV and NPV of 0.38 and 0.92.

Conclusion:
Pancreatic fibrosis grade at pancreatic cut margin can substitute assessment of pancreatic texture and is a more objective and reliable parameter. Future studies might use fibrosis grade for risk stratification in pancreatic surgery. Malnutrition is recognized as a preoperative risk factor for patients undergoing hepatic resection. To take preventive therapeutic actions before surgery, it is important to identify malnourished patients. However, there is no evidence, which existing nutritional assessment score (NAS) is suited best to predict the postoperative outcome in liver surgery.

Materials and methods:
All patients scheduled for elective liver resection at the surgical department of the University Hospital in Heidelberg and the municipal hospital of Karlsruhe were screened for eligibility. Before surgery, every patient was assessed to be at risk for malnutrition or not according to Nutritional Risk Index, Nutritional Risk Screening original and 2002, Subjective Global Assessment, Malnutrition Universal Screening Tool, Mini Nutritional Assessment original and SF, Short Nutritional Assessment Questionnaire, Imperial Nutritional Screening System I+II, Nutritional Risk Classification and the ESPEN malnutrition criteria. Throughout the patient's hospital stay, postoperative morbidity and mortality was tracked prospectively. The association of malnutrition according to each score and occurrence of at least one major complication was the primary endpoint, using a multivariable logistic regression analysis including established risk factors in liver surgery as covariates.

Results:
The population consisted of 182 patients. The percentage of patients labelled as malnourished by the NAS varied among the different scores, with the lowest being at 2.2% (Mini Nutritional Assessment) and the highest at 52.2% (Nutritional Risk Classification). In 40 patients (22.0%) a major complication was observed. None of the scores showed a significant association with the occurrence of major complications in the multivariable analysis.

Conclusion:
None of the twelve NAS investigated defined a state of malnutrition which was independently associated with postoperative complications. Other measures to determine malnutrition in liver surgery should be investigated prospectively. Ampullary cancer (AMPCA) is a rare gastro-intestinal malignancy. We aimed to evaluate long-term overall survival and prognostic factors after pancreatoduodenectomy (PD) in a large multicenter cohort.

Materials and methods:
Patients undergoing PD for AMPCA at 4 high-volume surgical centers from 1996 to 2017 were identified from prospectively maintained databases. Patient baseline characteristics, surgical and histopathological parameters, as well as long-term overall survival after resection were evaluated.

Conclusion:
T stage and R status were the strongest prognostic factors for long-term overall-survival in AMPCA patients undergoing PD. Consequently, curative resection is warranted in patients with localized disease and careful preoperative evaluation of resectability should be performed. The impact of preoperative biliary stenting (PBS) prior to pancreatoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC) in patients with hyperbilirubinemia is controversial.

Materials and methods:
Patients undergoing PD in the time period from 2014 to 2016 with or without PBS for PDAC were identified from the German DGAV-StuDoQlPancreas registry. The effects of PBS in patients with and without a history of jaundice were evaluated. Furthermore, the impact of different levels of hyperbilirubinemia and subsequent PBS on postoperative morbidity and mortality were analyzed.

Conclusion:
The majority of PBS procedures were performed in patients with no history of jaundice and lead to a significant increase in perioperative morbidity. Serum bilirubin levels > 15mg/dl were associated with higher postoperative morbidity and mortality. PBS correlated with higher postoperative complication rates in these patients. Pancreatic ductal adenocarcinoma (PDAC) is characterized by an extensive desmoplastic reaction. Pancreatic stellate cells, which are part of the normal pancreatic stroma, are activated by tumor cells and in their activated state they are the main source of collagen deposition within the tumor. The Activated Stroma Index (ASI) is the ratio of activated pancreatic stellate cells (PSCs) to collagen deposition. It has been previously described as a prognostic marker in PDAC. The usefulness of the ASI as a prognostic marker in patients after neoadjuvant chemotherapy with FOLFIRINOX has not been described before.

Materials and methods:
31 patients who underwent surgery after neoadjuvant chemotherapy following the FOLFIRINOX protocol for PDAC were analyzed by immunohistochemistry. α-smooth muscle antigen antibodies were used as a specific marker for activated PSCs. Anilinblue was used for collagen staining. The whole tissue sample was digitalized and the stained area was determined using computational imaging analysis. Analysis of overall survival was performed by Kaplan-Meier method.

Conclusion:
These data suggest that the ASI as well as the amount of collagen deposition could be useful prognostic markers for patients after FOLFIRINOX and resection, as survival curves showed a distinct trend in spite of remaining just below statistical significance. Main limitations are the small patient cohort (n=31) and the relatively short follow up time (mean=26 months). Potentially both markers could be useful for the establishment of response grading after neoadjuvant chemotherapy in pancreatic cancer and should therefore be further investigated. Distal cholangiocarcinoma (DCC) is a rare but over the last decade increasing malignancy and is associated with poor prognosis. According to the present knowledge curative surgery is the only chance for long term survival. This study was performed to evaluate prognostic factors for the outcome of patients undergoing curative surgery for distal cholangiocarcinoma.

Materials and methods:
75 patients who underwent surgery between January 2000 and December 2014 for DCC in curative intention were analysed retrospectively. Potential prognostic factors for survival were investigated including the extent of surgery using purposeful selection of covariates in multivariable Cox regression modeling.

Conclusion:
Preoperative biliary stenting reduces survival possibly due to delayed surgery. The extent of surgery is not an independent risk factor for survival except for patients with concomitant histological venous invasion. Oncological factors and postoperative surgical complications are independent prognostic factors for survival.

Background:
While the long-term survival rate among patients with periampullary and pancreatic carcinomas remains low, it can be influenced by various factors. The purpose of this retrospective study was to quantify the effects of body mass on postoperative complications and patient survival after pancreatic resections for underlying malignancy over a 20-year observation period.

Conclusion:
Patients with a BMI between 18.5 and 25 show better postoperative outcomes, regarding complications, hospitalization duration, and reoperation, than underweight or obese patients. Shortterm survival depends strongly on postoperative complications while patients with a higher BMI show better long-term survival rates.

Background:
Lesions in the posterosuperior liver segments (IVa, VII, VIII) have been described as the most challenging to address laparoscopically. While some studies have compared minimal invasively to conventional open approaches, virtually no attention has been given to distinguish between outcomes for patients with and without cirrhosis.

Materials and methods:
All consecutive patients undergoing liver resection at the Department of Surgery, Charité -Universitätsmedizin Berlin for at least one lesion in the posterosuperior segments between January 2014 and July 2018 were retrospectively analyzed. Based on the presence (n=43) or absence (n=115) of liver cirrhosis, patients were divided in two groups.

Results:
Evaluation of preoperative patient characteristics revealed patients with cirrhosis to be older (p<0.001) and with a higher likelihood for a history of diabetes (p<0.005) and alcohol consumption (p<0.0005). With regard to preoperative liver function, as assessed by LiMAx, cirrhotic patients had a markedly poorer score (p<0.005).
While a similar percentage in both groups had anatomical resection, patients in the no cirrhosis group had markedly less major resections (p<0.0005). Surgeries were, as a result, markedly longer in the no cirrhosis group (p<0.0005). With regard to the need for conversion and perioperative transfusion rate, no significant difference was noted between the two groups.

Conclusion:
Our data shows that the beneficial results conveyed through minimal invasive techniques also apply for cirrhotic patients with a lesion in the posterosuperior liver segments. No significant differences with regard to both safety and oncologic sufficiency was observed, when compared to non-cirrhosis. As these procedures entail a high degree of difficulty from a technical perspective, they should be performed in specialized centers.

Uniklinik RWTH Aachen
Background: Hilar en-bloc resection with portal vein resection (PVR) has emerged as the mainstay of treatment for patients with perihilar cholangiocarcinoma (PHCC). Whether liver resection should be carried out as extended left-(LH) or right-sided hepatectomy (RH) is still subject of ongoing debate. Here we evaluated perioperative complications and oncological outcome after RH or LH with hilar en-bloc resection and PVR in patients with PHCC.

Materials and methods:
Between 2010 and 2016, 91 patients with PHCC underwent surgery in curative intent at our institution. Perioperative and survival data from all patients undergoing surgical resection for PHCC were analyzed. PVR was carried out in all cases as well as arterial reconstruction (n=5) if necessary. Patients undergoing hepatoduodenectomy (n=8) or ALPPS (n=2) were excluded from the analysis.

Conclusion:
LH and RH hilar en-bloc resections demonstrate comparable 3-year OS. While RH hilar en-bloc resection might result in better long-term 5-year survival, this may be at cost of an increase in perioperative morbidity and mortality.

Uniklinik RWTH Aachen
Background: Cholangiocarcinoma (CCC) is a relatively rare malignancy that is typically diagnosed at an advanced disease stage. Major liver resection with portal vein reconstruction has evolved as the mainstay of treatment for patients with perihilar (PHCC) and intrahepatic cholangiocarcinoma (IHCC). Despite recent advancements, the overall-(OS) and recurrence-free survival (RFS) in CCC remains lower than for most other solid tumors. Here we aimed to identify prognostic markers of clinical outcome in CCCpatients that underwent surgical resection in curative intent.

Materials and methods:
Between 2010 and 2016, 162 patients with CCC (PHCC: n=91, IHCC; n=71) underwent surgery in curative intent at our institution. Preoperative characteristics, perioperative data and oncological follow-up were obtained from a prospectively managed institutional database. The associations of RFS and OS with clinico-pathological characteristics were assessed using univariate and multivariate survival analyses.

Results:
The

Background:
Liver resection constitutes the only therapeutic option for the intrahepatic cholangiocarcinoma (IHCCA). The aim of this work was to analyze the outcome of liver resection for patients with IHCCA, and to revisit the biological and surgical determinants of outcome, and the role of neoadjuvant and additive therapeutic modalities in our single-center cohort of patients during the last decade.

Materials and methods:
Using a prospectively filled database of all consecutive patients undergoing surgery due to a preoperative diagnosis of ICD-code C22.1 between December 2001 and December 2015 at the Department of General, Visceral, and Transplantation Surgery at the University of Heidelberg. Demographic, anatomical, clinical, operative, surgical pathologic and follow-up data of all patients with a final diagnosis of IHCCA were analyzed.

Conclusion:
Hepatectomy remains the only curative treatment for patients with IHCCA. Additive therapeutic strategies to prolong disease-free survival are still ineffective. Further, prospective studies are needed to improve the postoperative outcomes of IHCCA. Alveolar echinococcosis (AE) is a zoonosis mostly infesting in the human liver and often showing a tumor-like growth pattern. The increase of infected rural and urban fox populations and the extended routine use of imaging in the daily clinical practice have been associated with the growing incidence and the increasing diagnoses of human AE, respectively, in endemic regions including Switzerland.
Limited data now suggests that immunocompromised (IC) patients might be more susceptible to the infection and develop a more severe course of the disease. Therefore, we aimed to analyze the incidence of immune system modulating events in form of autoimmune diseases, intake of immunosuppressants and malignancies in our own patient cohort.

Materials and methods:
Retrospective data analysis of 136 patients treated for AE by either surgery or conservative treatment between 1971 and 2017 at the Department of Visceral Surgery and Medicine of the University Hospital Bern, Switzerland.

Results:
Our cohort consisted of 66 (48.5%) males and 70 (51.5%) females with a median age at diagnosis of 57 (16-88) years. Eighty-four (61.8%) patients received curative resections, 45 (33.1%) patients were treated with benzamidazole only due to inoperable disease and 7 (5.1%) patients had palliative surgeries in the beginning of the time frame analyzed. Interestingly, 46 (33.8%) patients had immune system modulating events in their medical history: 14 (10.3%) patients had immunosuppressive diseases including several different rheumatological autoimmune diseases, 3 (2.2%) were immunosuppressed medically post liver and kidney transplantation and 14 (10.3%) patients had malignancies including melanoma (n=3), lymphoma (n=2), liposarcoma (n=1), urothel-(n=1), breast-(n=3), skin-(n=2), colorectal-(n=1) and thyroid-(n=1) cancer. In 17 (12.5%) patients we detected other immunocompromising events in their medical history such as receiving long time steroids, or having tuberculosis or asthma earlier in their lives. Eighteen (13.2%) patients had significant risk factors documented including working as a farmer, hunter or veterinarian. No significant correlation was detected with tumor size or EM18, EM2 or EgHF levels. During the past decade we observed a significant increase (p<0.05) of immune-system modulating conditions associated to new diagnoses of AE. The overall survival of IC patients was significantly worse (p=0.01) compared with non-IC patients.

Conclusion:
The incidence of hepatic AE is increasing significantly, in particular in IC patients with a significant correlation with survival. Although we believe that IC patients in endemic regions should be advised about their increased risk of infection, the exact surveillance modalities and the role of serologic markers still need to be defined.

Background:
Several studies demonstrate a negative impact of postoperative complications on cancer-specific survival. A recent publication showed that delayed gastric emptying (DGE) significantly worsens survival in a Japanese population following pancreatoduodenectomy (PD). The underlying study examines the impact of DGE on cancer-specific survival in out tertiary care center.

Materials and methods:
Between January 2008 and June 2018 267 patients underwent pancreatoduodenectomy at our department. Of these, 123 were treated for pancreatic adenocarcinoma (PDAC). Patients were analyzed regarding demographic factors, intraoperative characteristics, morbidity & mortality and longterm oncological survival.

Conclusion:
Delayed gastric emptying does not influence cancer-specific survival in a European collective. The majority of patients with gallbladder disease undergo conventional laparoscopic cholecystectomy (LC) using four ports, however, new techniques such as SILS, NOTES and robotic assisted cholecystectomy are being promoted. We propose a three port technique for conventional LC with access from the left upper quadrant (LUQ) using a modified dome down technique (MDDLC) as a simple and cost effective alternative.

Materials and methods:
A total of 177 LCs performed between 6/2013 and 9/2018, were analyzed. The vast majority of cases was done without 1st assist and the nurse driving the 5mm 30 degree camera from the umbilical port. Trocars are placed in the LUQ (5mm), umbilicus (5 or 10-12mm), and between the two (5mm). The third troacar was replaced by a Teleflex minigrasper in 61 cases (34%). After the gallbladder (GB) serosa is incised on both sides, a window is created behind the GB midportion and widened towards fundus and infundibulum. Cystic artery and duct are dissected out obtaining the critical view ( Figure 1) and after the last fundus adhesion is cut, they are secured with clips or endoloop.

Results:
Median age of 121 women and 56 men was 54.7 (range 16.5-89.6) years. LC was done for acute cholecystitis (n=31), acute on chronic (n=50), chronic cholecystitis (n=62), other (n=34). In 160 cases (90%), the procedure could be completed with three instruments. In 23 cases additional instruments were used, which included a Keith needle to suspend the GB to the abdominal wall in seven patients, a minigrasper in one to help with GB dissection and a fourth 5mm trocar in 14 patients (for GB retraction in 7 cases, for cholangiography canule placement (n=2) and suction irrigation in one case; in the remaining four cases the additional trocar was inserted for second procedures (paraesophageal hernia repair, cystgastrostomy, appendectomy, right hemicolectomy, extensive lysis of adhesions). Thirty-six cases were done with two five mm ports and a minigrasper only. In 60% the MDDLC was completed, in 22% the MDDLC was switched to a traditional DDLC and 24 cases were started in traditional DD technique. Only the two first cases were done with exposure and division of CA and CD first followed by GB dissection. There were no vascular injuries but one anterior bile duct injury, which was managed with laparoscopic t-tube insertion. Conversion rate in this series was 0%. 35% of cases were done as outpatient procedures another 35% of patients required 23hours observation and 30% of patients were hospitalized.

Conclusion:
Three instrument MDDLC with trocar placement in LUQ is feasible and safe in easy and difficult cases and may have multiple advantages over the traditional used technique. The surgical trauma is reduces and in contrast to other new techniques no significant costs are added. Combination of partial hepatectomy and portal vein ligation has been established as a routine procedure to treat large or multiple liver tumors which require extended liver transection. Substantial atrophy of the deportalized liver lobe after portal vein ligation (PVL) is essential for compensatory hypertrophy of the protalized liver lobe. Previous study demonstrated that the balance of proliferation and apoptosis affected the extent of atrophy in deportalized lobe. Besides, it was evidenced that autophagy was promoted by partial hepatectomy and the activation of autophagy enhanced hepatocyte proliferation. However, the effect and mechanism of simultaneous partial hepatectomy (PHx) on regulating atrophy of deportalized lobe remains unclear. We hypothesized that the simultaneous PHx abrogated atrophy of the deportalized liver lobe by inducing hepatocyte proliferation, promoting autophagy and suppressing apoptosis in a size-dependent manner.

Materials and methods:
Lewis-rats were subjected to experimental procedures consisting of 20%PVL+70%PHx and 70%PVL+20%PHx respectively. Control groups consisted of 20% PVL only and 70%PVL only. Rats were sacrificed on postoperative day (POD) 1, 2, 3 and 7(n=6/group/time points). Individual liver weight/body weight was calculated. BrdU staining and TUNEL staining were performed to evaluate the proliferation index and apoptotic density. qPCR for mRNA of Proliferating cell nuclear antigen (PCNA) was performed to confirm the proliferation index. Protein levels of LC3-II and caspase3/cleaved caspase3 were detected by western blot.

Results:
The deportalized liver lobe adjusted its size in weight differently. Interestingly, the additional small resection reduces the hepatic atrophy of the ligated lobe, whereas the large resection caused a significant increase of hepatic volume of the deportalized lobe. Simultaneous resection induced a size dependent low but substantial hepatocytes proliferation rate (maximal 6.3% and 3.6% when performing either 70%PHx or 20% PHx). Furthermore, additional resection significantly suppressed apoptotic in the deportalized liver, confirming by both TUNEL and protein levels of cleaved caspase3. Of significance, the protein levels of LC3-II elevated in additional large resection compared to small resection.

Conclusion:
Atrophy of the deportalized liver lobe was counteracted by the simultaneous PHx. The simultaneous PHx did not only induce mild hepatocyte proliferation, but also did suppress hepatocyte apoptosis significantly in the deportalized liver lobe in a size dependent manner. Meanwhile, autophagy was activated in deportalized lobe after additional large resection and might be involved in suppressing apoptosis. Early detection of pancreatic ductal adenocarcinoma (PDAC) at surgically manageable stages is crucial and offers the best chance of increasing survival. Lysosome-associated protein transmembrane-4-beta (LAPTM4B) is up-regulated in a wide range of cancers associated with poor prognosis. However, the clinical impact of LAPTM4B as diagnostic and prognostic marker in PDAC remains unknown. The aim of the present study was to investigate the expression of LAPTM4B as liquid biopsy marker in PDAC.

Materials and methods:
Tissue and preoperative blood samples of 108 patients with PDAC UICC Stages I to IV (n=56), chronic pancreatitis (n=21), pancreatic cystadenoma (n=14), and age-mached healthy blood serum controls (n=17) were collected between 2015 and 2017 prospectively. Expression of LAPTM4B was analyzed by immunohistochemistry, Western blotting and ELISA. Statistical analysis was performed with SPSS Statistics using Mann-Whitney U test or Kruskal-Wallis test, Fisher's two-tailed exact test, and receiver-operating-characteristic (ROC) method. Values for p<0.05 were considered to be statistically significant.

Results:
Expression of LAPTM4B was significantly increased in tumor tissue and in blood serum samples of patients with PDAC versus healthy controls (p=0.002; p<0.001) and versus chronic pancreatitis (p=0.02; p=0.031). Circulating LAPTM4B could well discriminate PDAC from non-PDAC with an Area under the curve (AUC) of 0.89 (95% confidence interval 0.79 to 0.99; p<0.001).

Conclusion:
LAPTM4B shows high potential as liquid biopsy marker in PDAC patients. Results of survival analysis and of in vitro functional studies are currently pending. Postoperative liver dysfunction (LD) still represents a severe complication in patients undergoing liver resection and its incidence is estimated at 10-20%. As postoperative LD commonly develops as a result of delayed liver regeneration, it is most relevant to reach a comprising understanding of this process. Thus, we aimed to investigate the perioperative dynamic of circulating metabolites, as well as differences in the metabolic profile of patients with and without postoperative LD using an unbiased metabolomics approach.

Materials and methods:
Plasma from 95 prospectively included patients was collected preoperatively and on the first and fifth postoperative day (POD5). Per patient and time point 180 metabolites were assessed using the Biocrates p180-kit. Development of LD was prospectively recorded.

Results:
21 patients (19.95%) suffered from postoperative LD. We observed significant dynamics in the metabolic profile after liver surgery, that tended to normalize upon POD5. Further, we were able to document differences in the concentration of 120 metabolites between patients with and without postoperative LD. Interestingly, the family of sphingolipids showed an evident accumulation of differentially abundant metabolites in patients with LD at several time points, while the total amount of sphingolipids did not differ.

Conclusion:
Within this study we present the first data on the metabolic profile in patients undergoing liver resection and in patients with delayed liver regeneration. While we found a plethora of potential markers for postoperative LD at various time points, we also present hypothesis generating data and the opportunity to characterize potentially targetable pathways for improvement of postoperative liver regeneration.

Universitätsklinikum Jena
Background: Late diagnosis and aggressive dissemination are main reasons why hepatocellular carcinoma (HCC) are the second most common cause of cancer-related deaths worldwide. Primary resection or, in case of liver cirrhosis or bilobary manifestation, liver transplantation are the only curative therapystrategies. The time between diagnosis of HCC and resection or transplantation is called "bridgingtime", in which tumor mass and biological activity can be down-regulated by supporting therapies like transarterial chemoembolization (TACE) or selective internal radiotherapy (SIRT). It was shown in former studies that free tumor cells after resection are associated with poor outcome in future. Aim of this study was to show that vital circulating tumor cells (CTC) can be used as a prognostic factor to prevent metastasis although supportive therapies and resection/ transplantation of the primary tumor is already done.

Materials and methods:
From 2012 to 2018, 186 HCC patients who underwent supportive therapy as TACE or SIRT, resection or transplantation at the Department of Surgery at the University Hospital of Jena were enrolled. Blood specimens were obtained before or after surgical or conservative intervention and analyzed for EpCAM+/ Propidium-vital CTC. Follow-up data and blood samples were taken from 52 patients.
Retrospectively the data were correlated to patients ' clinical data.

Results:
All 186 patients, 165 male and 21 female, could be included. 71 patients were resected or transplanted, 115 were bridged to transplantation or underwent palliative therapy. 52 patients were followed up with analysis of blood specimens. 12 of them got metastasis during follow up. EpCAM positive CTC during follow up showed in 83% (n=10) a positive correlation to malignant dissemination in future (p< 0,01).

Conclusion:
Blood-stream detection of vital CTC is a good tool to detect malignant dissemination and could identify high-risk patients that can profit from a more aggressive therapy after resection or during bridging therapy like similar, for example, intake of protein kinase inhibitors. Indeed, prospective studies with well evaluated protocols are needed to underline these data and to show how to treat patients during bridging therapy to prevent them from malignant dissemination. About one third of the patients with colorectal cancer will develop liver metastasis within three years after diagnosis, but only 15-20% will be legible for resection. Although advanced medical therapy results in better survival, resection of liver metastasis is the only curative option. Anatomical or nonanatomical resection has no consequences for tumor recurrence. Patients that were considered as unresectable, a two-staged hepatectomy such as ALPPS provide a technique to improve resectability in about 20% of those patients. This procedure has an extensive regenerative response of the liver parenchyma.
About 57% develop recurrence after initial liver resection and re-resections are described as a safe and feasible option. Studies show a 5-year-survival rate of 33-75% with no perioperative mortality. The only difference of the repeated resection, compared to the first resection, is that the surgical technique becomes more difficult. However, re-resections after ALPPS for colorectal liver metastasis (CRLM) are not described. In this case series, we examine the feasibility and outcome for ALPPS in the setting of repeated liver resection for CRLM. It is unknown whether the regenerative response after ALPPS completion is still obtainable for another resection of liver parenchyma.

Materials and methods:
All patients that underwent resection for recurrence for CRLM after the completion of ALPPS procedure were included in the study. Operation details, volumetric analysis and complications (according to Clavien-Dindo) were assessed for stage-1, stage-2 and the resection for recurrence. Demographics and survival were analyzed for each patient. Data are reported as median (interquartile rage), mean (standard error), and numbers with proportions (%), where appropriate. Statistical analysis was performed using SPSS v23© for Mac.

Results:
Out of 68 ALPPS procedures during the study period from 11/2010 until 12/2017, we performed 46 ALPPS procedures for CRLM, of those 42 were completed (91%). Overall, six patients underwent resection for recurrence. During stage-1 the majority underwent classic ALPPS with a low morbidity (CCI of 10,5). The mean sFLR before stage-2 was 33% and only extended resections were performed during stage-2, with half of the patients receiving an additional atypical resection of the future liver remnant.
After completion of stage-2 the mean time to recurrence was 328 days. The majority of patients underwent atypical resection for recurrence (n=5). Of those, one patient had additional microwave ablation. One patient even received a segmentectomy. Mean operation time was 193 Minutes. The perioperative morbidity was low with a CCI of 5,6 and no perioperative mortality occurred. Furthermore, no posthepatectomy liver failure was observed. Two patients even received a third hepatectomy for a second recurrence with no perioperative mortality. The one-and three-year survival was 83% and 56%, respectively.  This is the first study about resection for recurrence after the completion of ALPPS. Even after the extensive regenerative response after ALPPS procedure, we show that the surgical approach in this setting is feasible with no perioperative mortality. Furthermore, the survival of those patients seem to be comparable with the current literature for patients undergoing repeated liver resections.

Universitätsklinikum Düsseldorf
Background: Overall survival after surgery for pancreatic ductal adenocarcinoma (PDAC) remains poor. While some studies suggest that positive nodal status (N1) is one of the most important prognostic factors after margin-negative (R0) resection, other data imply that nodal disease is not associated with prognosis. Thus, the aim of this study was to investigate the prognostic value of lymph node (LN) staging systems such as the pN categorization, metastatic LN ratio (LNR) and log odds of positive LNs (LODDS). In addition, we evaluated the prognostic relevance of LN metastasis in different LN stations by using the different LN staging systems.

Materials and methods:
Clinicopathological data from 308 patients who underwent pancreatic resection for PDAC between 2003 and 2018 were analyzed. Histopathologic reports were re-assessed to gather data on the nodal status. Both LNR (ratio of positive LN to examined LN) and LODDS [log(positive LN+0.5)/(total LN+0.5)] were calculated from the peripancreatic and total LN yield, respectively. In addition a separate LN mapping was performed on the interaortocaval (IAC), hepatoduodenal ligament (HDL), portal vein (PV), celiac trunk (CT) and superior mesenteric artery (SMA) stations. Individual cut off levels and subgroups were set both for LNR and LODDS by the median and quartiles respectively. Overall survival (OS) was determined for all patients by the Kaplan-Meier method and Cox regression.

Results:
Of the 308 patients, 264 patients (85,7%) underwent partial pancreaticoduodenectomy (pPD). Moreover, 14 (4,5%) and 29 patients (9,4%) received total pancreatectomy and oncologic pancreatic tail resection, respectively. 248 patients (80,5%) showed LN infiltration (N1), while 46 patients (15%) presented with distant metastasis (M1). In contrast to the pN status, multivariate analysis identified(MV) M1 situation, positive surgical margins (R1) and tumor localization as independent prognostic factors. Of note, LNR and LODDS were significantly associated with worse overall survival (OS). Both, LNR and LODDS that were specifically assessed in the peripancreatic LNs correlated with poor survival in UV and MV analysis. However, LNR turned out to be a stronger independent prognostic factor than LODDS. In further subgroup analyses including only R0 resected PADCs independently of the localization (head, body, tail), R0 resected pancreatic head cancer or pancreatic head cancer independently of resection margins, again pN failed to be a prognostic factor. Importantly, LNR remained to be an independent prognostic factor in the total and peripancreatic LN. In contrast, the LODDS predicted survival only for the total LN yield. In addition, LN mapping showed positive LNs in the IAC, HDL, PV, CT and SMA stations for 42, 26, 12, 17 and 18 patients, respectively. Interestingly, positive SMA lymph nodes correlated with poor OS in MV analysis [HR=3,0 (95% CI 1.4-6.4)]. Importantly, hospital stay and morbidity showed no significant difference in cases with extended compared to standard LAD.

Conclusion:
In contrast to pN, LNR and LODDS are powerful prognostic factors in PDAC. Therefore, LNR and LODDS should be included in pathologic reporting after PDAC resection and taken into consideration for the prognostic assessment of PDAC patients. Moreover, we show that positive IAC LNs had no impact on survival, in our cohort of PDAC patients, supporting an extended LAD for PDAC.

Universitätsklinikum Düsseldorf
Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy and most patients present with locally advanced disease. To achieve tumor clearance, venous resection of the portal vein (PV) or superior mesenteric vein (SMV) during partial pancreatoduodenectomy (pPD) has steadily been gaining acceptance. It is unclear whether preoperative radiologic assessment is a viable tool to identify patients with PV/ SMV involvement. Nevertheless, previous studies have shown that intraoperative re-resection to achieve secondary margin clearance does not influence overall surival, thus survival in primary R0 resections is superior. In addition further pathological studies have shown, that the medial resection margin, the adjacent site of the PV/SMV, is the main site of microscopic tumor infiltration (R1). Consequently, the aim of this study was to investigate the correlation of preoperative CT morphological and post-operative histopathological findings. Furthermore, clinicopathological parameters were analyzed to identify significant survival determinants.

Materials and methods:
We reviewed the records of patients, who underwent pPD between 2003 and 2018 in our Institution. We herein analyzed clinicopathological data, morbidity, mortality and survival outcome. Pre-operative CT scans were retrospectively re-analysed by an experienced radiologist in a blinded fashion and correlated with histopathological and clinical findings.

Results:
Pre-operative CT scans were available for re-assessment in 179 patients whom received pPD for PDAC. 4 patients received neoadjuvant treatment. 132 patients were staged UICC IIB (8th edition). Complete tumour clearance was achieved in 141 patients. 74 patients received portal vein resection during pPD. All patients received an adjuvant treatment regime. In 113 patients (63%, group NIF), tumour contact with the PV/SMV was not visible pre-operatively, whereas in 67 patients (37%, group IF) tumour contact was suspected. In both groups, clinicopathological variables were homogeneously distributed. In group NIF, venous resection was performed in 35 patients, but venous infiltration was confirmed histopathologically in only 5 patients (14%). In group IF, venous resection was performed in 38 patients, with an actual infiltration rate of 66%. Suspected venous infiltration correlated significantly with actual infiltration (p<0.01). Portal vein resection was not a predictive factor for prolonged hospitalization (average 28 vs 31 days). On univariate analysis, factors influencing OS included UICC, tumour grade, R-status and CT-suspected portal vein infiltration. On multivariate analysis only Rstatus was associated with poor OS.

Conclusion:
Pre-operative assessment of PV/SMV infiltration correlated with histopathological findings. In survival analysis, only R status was an independent prognostic factor. PV/SMV resection did not increase morbidity nor prolong hospitalization. Furthermore, previous studies showed no survival benefit after intraoperative re-resection to achieve secondary margin clearance This suggests that PV/SMV resections should be performed when tumor infiltration is suspected to obtain primary margin clearance in order to increase local tumor control and improved survival outcome. Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer death by 2030. This is mostly to due to early local and distant metastasis, even after surgical resection. Knowledge about patterns of recurrence in different patient populations could offer new therapeutic avenues.

Materials and methods:
Clinicopathologic data were collected for 546 patients who underwent resection of their PDAC between 2005 and 2016 from two tertiary university centers. Patients were divided into an upfront resection group (n=394) and a neoadjuvant group (n=152).

Conclusion:
Time to and total number of recurrence was significantly shorter and smaller in PDAC patients with lymph node positive disease. However, patterns of recurrence for pN0 and pN1 patients were identical.  Treatment of liver malignancies invading the hepatic veins and/or inferior vena cava is a challenge even for the experienced HPB-surgeon. The ante situm technique allows for luxation of the liver in front of the situs to improve access to the hepatocaval confluence and the vena cava but usually includes cold perfusion and veno-venous bypass to perform tumor resection. Experience with modified ante situm resection relying only on total vascular occlusion at Hannover Medical School is reported.

Materials and methods:
Retrospective analysis of 15-year experience with ante situm resection without application of neither cold perfusion nor veno-venous bypass is presented.

Results:
Ante situm technique was applied on 8 patients without cold perfusion nor veno-venous bypass. Five patients were treated due to intrahepatic cholangiocellular cancer and 1 case each for mixed cholangio-/hepatocellular carcinoma, colorectal liver metastasis and pheochromocytoma. Trisectorectomy (n=4), left hemihepatectomy, right hepatectomy, atypical resection or mesohepatectomy (each n=1) was performed in combination with dissection of suprahepatic/retrohepatic vena cava/hepatic veins. Venous reconstruction was achieved by reimplantation of hepatic veins with/without vascular replacement using allogeneic donor veins or PTFE-grafts. Median total vascular occlusion of the liver was 23 minutes. Severe morbidity occurred in 3 patients (Dindo-Clavien >3A). R0-status was achieved in 6 cases with a median overall survival of 33.5 months.

Conclusion:
Ante situm liver resection can be applied without cold perfusion nor veno-venous bypass with acceptable morbidity and mortality in selected cases. However, this procedure remains challenging due to the need for complex vascular reconstruction. Despite substantial improvements in surgical practice leading to decreased mortality in recent decades, pancreatic surgery is still associated with substantial rates of postoperative morbidity of up to 50 %. Postoperative morbidity comprises predominantly surgical or pancreas-specific complications, such as postoperative pancreatic fistula, bile leakage, delayed gastric emptying, postpancreatectomy haemorrhage, intra-abdominal fluid collections or abscess. These complications can result in reduced quality of life of patients, are associated to prolonged hospital stay and increased health care costs and might delay adjuvant chemotherapy or further necessary treatment.

Materials and methods:
The current analysis includes individual patient data of six high quality randomised controlled trials on different pancreatic surgical interventions, which were conducted by the Study Center of the German Surgical Society (SDGC).
Cumulative frequency of individual, postoperative complications was calculated. Risk factors for pancreas-specific complications were identified by uni-and multivariate analysis. Covariates included baseline factors (e.g. age, gender, BMI, smoking status, diabetes, ASA-classification, immunosuppressants, comorbidities) and surgical factors (e.g. length of surgery, blood loss, texture of the pancreas).
A multivariate logistic regression analysis and the Cox regression will be applied. Two-sided P values will be computed and P <= 0.05 will be considered statistically significant.

Results:
Data on a total of 1918 patients were included in this analysis. 1112 were male, mean age was 61.2 years (95% CI 60.7 -61.8) and average BMI was 25.0 kg/m2 (95% CI 24.8 -25.2). 962 patients underwent a partial pancreatoduodenectomy, 515 patients received a distal pancreatectomy, in 170 cases a duodenum-preserving head resection was performed, 79 patients received a total pancreatectomy and in 192 cases other operations were performed.
Clinically relevant postoperative pancreatic fistula occurred in 11.6 % after partial pancreatoduodenectomy and 20.9 % after distal pancreatectomy. 24.0 % of patients after partial pancreatoduodenectomy and 3.8 % after distal pancreatectomy developed delayed gastric emptying. Postpancreatectomy haemorrhage was described in 9.1 % after partial pancreatoduodenectomy and 5.7 % after distal pancreatectomy.
Furthermore 14.2 % had an intra-abdominal fluid collection after partial pancreatoduodenectomy and 27.1 % after distal pancreatectomy. In 3.0 % of the cases a bile leakage was described after partial pancreatoduodenectomy and in 1.1 % after distal pancreatectomy.
Analysis of risk factors is currently ongoing, however results will be presented at the surgical congress.

Conclusion:
The aim of this post-hoc analysis is to identify clinically relevant risk factors for postoperative morbidity and mortality after pancreatic surgery based on data from six high quality randomised controlled trials. The results might be the basis for a more reliable preoperative risk assessment, patient counselling and an individualized risk reduction in the future.

Universitätsklinikum Erlangen
Background: Pancreatic cancer is one of the leading causes of cancer death worldwide, with an overall 5-year survival rate of less than 5%. Survival rates vary among patients, especially with advanced pancreatic cancer. The nutritional status plays an important role in prognosis of different type of cancers, the immunonutritional status is reflected via the prognostic nutritional index (PNI), calculated on serum albumin and peripheral lymphocyte count. Systemic inflammatory response parameters, neutrophil to lymphocyte ratio (NLR), lymphocyte to monocyte ratio (LMR), consider the pro-tumorigenic properties of neutrophils respectively while considering the protective effect of lymphocytes. The purpose of this study was to determine the prognostic value of different easily available parameters for a better risk stratification in pancreatic cancer patients.

Materials and methods:
From 2010 to 2016, we conducted a retrospective analysis of 167 patients with pancreatic cancer who underwent surgery for curative intention. Routine laboratory measurements, including white blood cell count: neutrophil, lymphocyte, monocyte and serum albumin were performed prior to surgery. The NLR, LMR and PNI: serum albumin (g/l) + 0,005*total lymphocyte count (per mm³) were calculated. Receiver operating characteristic (ROC) analysis and Youden index were used to identify the best cutoff values. Survival curves were determined by the Kaplan-Meier method.

Conclusion:
NLR and PNI, simple and easily to derive markers, are useful prognostic indicators for OS in patients with pancreatic cancer. Further independent prospective study's are needed to help guide risk stratification for treatment decisions, especially to find out patients who did not benefit from surgery. With increasing numbers of patients treated for locally advanced and borderline resectable pancreatic cancer, the number of portal vein resections (PVR) is increasing. While the operative technique is clearly defined, data for the postoperative management after PVR after scarce. Furthermore, it is unclear whether patients with PVR should receive anticoagulation beyond standard thromboprophylaxis after surgery. Thus, the present study examines the incidence, risk factors, and prevention of PVT after PVR.

Materials and methods:
Data on all patients with PVR and pancreatic surgery of any kind between 01/2014 and 12/2017 from two pancreatic centers was collected. Subsequently, patient data was analyzed for the incidence of PVT, operative and non-operative risk factors, and thromboprophylaxis.

Results:
Overall, 132 patients with PVR were analyzed. Of those, 4.6% (n=6) had PVT within 30 days (PVT<30d) postoperatively. Neither the type of PVR nor any other of the investigated risk factors was associated with PVT <30d. PVT<30d was not associated with a change in hospital length of stay or mortality. Additionally, therapeutic dosing of thromboprophylaxis or thromboprophylaxis for more than 4 weeks postoperatively had no effect on the incidence of PVT<30d.

Conclusion:
PVR can be done safely with a low risk of PVT. Standard postoperative thromboprophylaxis with prophylactic dosing is sufficient to prevent PVT.

Klinik und Poliklinik für Chirurgie, München
Background: Brahma-related gene 1 (Brg1), a catalytic subunit of the SWItch/Sucrose Non-Fermentable (SWI/SNF) complex, is known to be involved in proliferative cell processes. Liver regeneration is initiated spontaneously after injury and leads to a strong proliferative response. The aim of the study was to investigate the role of Brg1 in liver regeneration following partial liver resection in mice.

Materials and methods:
In this study, a hepatocyte-specific Brg1 gene knockout mouse model was used to analyse the role of Brg1 in liver regeneration by performing a 70% partial hepatectomy (PH). Liver regeneration was analysed by liver/body weight ratio and cell proliferation rate. Different cellular pathways were analysed by RNA sequencing.

Results:
After PH, Brg1 was significantly upregulated in wildtype mice. Mice with hepatocyte-specific Brg1 gene knockout showed a significantly lower liver to body weight ratio 48 h post-PH concomitant with a lower hepatocellular proliferation rate compared to wildtype mice. In addition, proliferation rate of the hepatocytes was significantly higher in wildtype mice after PH compared to the proliferation rate of hepatocyte-specific Brg1 gene knockout mice. RNA sequencing demonstrated that Brg1 controlled hepatocyte proliferation through the regulation of several cell cycle genes.

Conclusion:
The data of this study reveal a crucial role of Brg1 for liver regeneration by promoting hepatocellular proliferation through modulation of cell cycle genes and, thus, identify Brg1 as potential target for future therapeutic approaches.

Background:
Hepatocyte growth factor (HGF) is a complete hepatic mitogen and is considered an important initiator of liver regeneration. Liver regeneration after partical hepatectomy (PHx) is known to be a complex process where liver sinusoidal endothelial cells (LSECs) play an important role. LSECs are one of the most important liver cell types that produce HGF, but the exact contribution of LSECs to liver regeneration remains to be defined.

Materials and methods:
In order to investigate the effects of HGF signaling on liver regeneration, Stab2-Cretg/wt;HGFfl/fl mice, where HGF is specifically knocked out in LSEC, were used. These mice underwent an 70% PHx and the kinetics of liver-to-body weight ratio, hepatocyte proliferation, HGF/c-MET signaling pathways and cell-cycle-associated genes were analyzed at different time points after PHx. In addition, RNA sequencing was performed.

Results:
We demonstrated that HGF-LSECKO mice showed a significantly reduced liver-to-body weight ratio compared to the control group at 72 hours after PHx. HGF-LSECKO mice had a higer mortality after PHx and the proliferation of hepatocytes was significantly impaired at 48 hours after PHx in HGF-LSECKO mice.

Conclusion:
HGF signaling plays a vital role in the early stage of liver regeneration after PHx in mice. This signaling pathway is not only essential for liver regeneration after injury, but also crucial for the growth of the liver.

Universitätsklinikum Hamburg-Eppendorf
Background: Although mortality associated with liver surgery has decreased, high morbidity rates are still of major concern. This study aimed to identify the prevalence of, and risk factors for infectious complications after liver surgery.

Materials and methods:
A prospective database of 493 consecutive liver resections performed by the University Hospital of Hamburg-Eppendorf between 07/12 and 01/2017 was analyzed. Infectious complications were classified in non-liver related (NLR) infections and liver related infections (LR). Risk factors that were significantly associated with infectious complications in univariable models were included in a multivariable logistic regression model.

Conclusion:
Infectious complications after liver resection are still a major concern and a broad spectrum of patient, disease and surgery related risk factors could be identified. The majority of occurring infections are not directly liver related and might be addressed by focused assessment and optimization of perioperative care like in an enhanced recovery after surgery program (ERAS).

Universitätsklinikum Bonn
Background: Biliary tract cancer (BTC) is an aggressive malignant neoplasm with extremely few therapeutic options. The characterization of the immune cell-related microenvironment is crucial in order to identify novel therapeutic targets. The aim of this study was to assess prognostic factors associated with immune cell infiltration in BTC.

Materials and methods:
Tumor samples from 45 patients who had undergone surgical resection for BTC between 2014 and 2017 at the University Hospital Bonn were investigated. Using immunohistochemistry, we identified tumor-infiltrating T lymphocytes (CD4 , CD8 ), natural killer cells (perforin ) as well as tumor regulatory T cells (CD103 ). Furthermore, the overall quantity and relative cell density were analyzed. Clinical data were obtained and the clinicopathological impact of immune cell infiltration was evaluated.

Results:
Tumors with a high density of infiltrating T lymphocytes were characterized by a longer overall survival (25±7.7 months vs. 28±5.6 months; P=0.039). This positive association between T lymphocyte infiltration and survival was particularly evident in the subgroup of extrahepatic malignancies (OS 25±4.5 months vs. 34±3.4 months; P=0.048). The strongest association with overall survival was found within the CD8 relative density, which turned out to be an independent prognostic factor (P=0.019). The CD4 /CD8 ratio was similar in extrahepatic and intrahepatic BTC. In our preliminary data, a high density of CD103 cells correlated with longer overall survival.

Conclusion:
The immune microenvironment plays a crucial role in cancer development and response to therapy. Our study underlines the complexity of the tumor infiltrating T cell population, which represents a promising target for immunomodulatory agents.

Universitätsklinikum Hamburg-Eppendorf
Background: Although mortality associated with pancreatic surgery has decreased dramatically, high morbidity rates are still of major concern. Enhanced recovery after surgery (ERAS) protocols have been developed for most major abdominal surgeries. Specific guidelines also for duodenopancreatectomy have been published, but mainly by extrapolating data collected from colorectal surgery.

Materials and methods:
An ERAS protocol for pancreatic surgery has been implemented successfully at the University Hospital in Hamburg. Consecutive perioperative data of 121 unselected patients undergoing duodenopancreatectomy could be prospectively entered in the ERAS database from 02/16 till 05/18. The control group consisted of 36 historical duodenopancreatectomies of the pre-ERAS era, perioperative data was assessed retrospectively.

Results:
The ERAS protocol could be successfully implemented for pancreatic surgery in our hospital, the adherence to the protocol starting from 24.0% in the pre-ERAS era constantly increased to 67.9% in 2018. Regarding the different perioperative phases, the adherence is highest in the pre-operative phase: 94%, still 82% in the intra-operative phase but just 38% in the regarding the postoperative phase.
Nevertheless, by the implementation of an ERAS protocol in pancreatic surgery, median length of stay could be reduced by 4.4 days (19.3 vs. 14.9d) as well as severe complications by 5.5% (CD >=IIIa: 36.1 vs. 30.6%) without negatively affecting the readmission rate (11.1 vs. 7.4%). Pancreatic fistulas could be reduced by 6.5% (22.2 vs 15.7%), as well as postoperative obstipation by 9.4% (11.1 vs 1.7%). Evaluation of ASA and PPOSSUM Score indicates even patients of a slightly higher perioperative risk in the ERAS-group.

Conclusion:
The implementation of an ERAS-program for pancreatic surgery is feasible and successful. Pure extrapolation of data from other ERAS organ protocols is not sufficient.
To further develop the ERAS program we need to make sure that we are part of the same ERAS program. If everybody establishes its own modified ERAS protocol, ERAS will not be more than a pure marketing tool. Abstracts -DGCH Annual Congress 2019-Munich, March 26-29 • DOI 10.1515/iss-2019-2001 s99 Innov Surg Sci 2019; 4, (Suppl 1): s1-s205

Universitätsklinikum Magdeburg
Background: Necrotizing pancreatitis is the most severe clinical course of acute pancreatitis which is still associated with a substantial morbidity and mortality. The formation of "Walled-Off Necrosis" (WON) is relatively common and in this case, a secondary infection can occur. Minimally invasive endoscopic and surgical interventions have priority in the therapy. In this context, percutaneous and endoscopic ultrasonography(EUS)-guided internal drainages are preferred.

Materials and methods:
To further improve the treatment, an algorithm is required for an appropriate approach. Therefore, the monocentric population of our institution was investigated retrospectively in prospectively collected peri-interventional data (study design). Overall, 105 patients with necrotizing pancreatitis and infected WON undergoing translumenal endoscopic necrectomy (inclusion criteria) at the Municipal Hospital ("SRH Wald-Klinikum GmbH") at Gera (Germany) from 2004 to 2017 were identified.

Results:
In total, 68 men and 37 women were enrolled in the study (median age, 59 years). Mean hospital stay was 44 days. Fourty five % of the patients were treated at the intensive care unit; 86 % of the cases presented with a bacterial infection of the WON whereas in 40 %, mycotic infection was found. First interventional measure was performed after a mean time period of 28 days; in 54 %, this was a percutaneous drainage. Internal drainages were used in 46 patients (43.8 %) after a mean time period of 35 days. The combination of percutaneous and internal drainages permitted an excessive lavage, which was performed in 57 patients (54.3 %). Eighty seven individuals (82.9 %) were treated by internal (transluminal) endoscopic necrectomy and in 8 subjects (9.2 %), a percutaneous necrectomy was additionally performed. In only 20 patients (19 %), complete necrectomy was achieved. It was found that for the therapeutic success, long-term internal drainage was substantially important. Approximately 30 % of patients were discharged with an AxiosTM stent (Boston Scientific) and 60 % with pigtail drainages in situ. Complications such as bleeding or perforation occurred in 8 cases (7.6 %). Eleven patients underwent surgical intervention (rate, 10.5 %). Mortality was 7.6 % (n=8). The stents were removed after 3 months. There was a recurrence of cyst or WON in 8 patients (rate, 7.6 %), only 4 patients (3.8 %) needed endoscopic re-treatment.

Conclusion:
Step-up approach to be used as the basic algorithm in acute necrotizing pancreatitis comprising external drainage, internal/external drainage (+ rinsing via drainage) and endoscopic necrectomy appears feasible, efficient and safe. In case of infected necrosis, intensive care and antibiotic treatment are as important as the drainage of the WON. In septic patients, percutaneous drainage is preferred. In stable patients, internal drainage or the combination of internal and percutaneous drainage was/were used. The endoscopic necrectomy was performed if the clinical status had not improved despite a sufficient internal and external drainage. The complete necrectomy is not an indispensable prerequisite for a favorable outcome but, however, the sufficient long-term drainage is essential.

Background:
Thromboembolic disease is a potentially serious complication in bariatric surgery patients. Direct oral anticoagulants (DOAC) have been investigated in orthopedic surgery patients. DOAC data after bariatric surgery is still limited to the early postsurgical period. Whether postsurgical mid-term adaptations due to anatomical and physiological alterations influence drug pharmacology is currently not known. The aim of this study was to investigate the influence of weight loss and type of bariatric surgery on mid-term postsurgical pharmacokinetic and pharmacodynamic parameters of rivaroxaban.

Materials and methods:
In this monocentric study, bariatric patients received a single oral dose of rivaroxaban (10 mg) six to eight months after Sleeve Gastrectomy (SG) or Roux-en-Y-gastric bypass (RYGB). Pharmacokinetic and pharmacodynamic parameters were assessed and compared with pre-bariatric surgery results.

Results:
We included 6 RYGB and 6 SG patients. Percent excess weight loss (%EWL) was 71.4% (interquartile range 56.4, 87.9) in the SG group and 76.6% (64.5, 85.7) in the RYGB group. Rivaroxaban mean areas under the curve (AUC) 6 to 8 months after the bariatric procedure (922.4 µg*h/L, coefficient of variation 43.2) were comparable to those measured preoperatively (952.6.4 µg*h/L, 16.8). There was no relevant difference between the two surgical procedure groups. Rivaroxaban led to a decrease of prothrombin fragments F1+2 over 12 h after oral intake confirming in vivo efficacy.

Conclusion:
Significant weight loss and altered anatomy after RYGB and SG procedures do not appear to affect the pharmacokinetics and pharmacodynamics of prophylactic rivaroxaban. A single dose of Rivaroxaban was well tolerated and considered safe in this trial.

Knappschaftkrankenhaus Recklinghausen
Background: Bariatric interventions are generally performed in full inpatient settings in Germany with a residence time of 2-7 days. For the gastric band system, which is hardly pursued today, we were able to establish a purely outpatient treatment in a previous examination (> 100 cases). In the meantime, the first publications from the USA, France and Canada show that sleeve gastrectomy in selected patients can also be carried out on an outpatient basis without increased risk. By the very low rate of complications of the procedure, the question arises as to whether sleeve gastrectomy can also be successfully performed in Germany as an outpatient / day surgery operation. As part of the surgical preparation, individual patients ask the question about an ambulatory sleeve gastrectomy.

Materials and methods:
According to the patient's request, an ambulatory sleeve gastrectomy was considered according to the following criteria. ASA I (normal, otherwise healthy patient), BMI 40 kg / m2 (+/-5 kg / m2), adult accompanying person, stay postoperatively within 20 km radius of the hospital, possibility to search the hospital at any time and the outpatient check-up on the following day. Telephone accessibility over 24 hours. Operative and postoperative setting: opiate-free anesthesia and postoperative analgesia, uncomplicated intraoperative course. Unremarkable postoperative course (Hb, O2 saturation), low analgesic demand, mobilization, undisturbed oral fluid intake (> 500ml), continuing patient request for outpatient surgery. Participation in a patient survey.

Results:
The inclusion criteria were met by 14 patients aged 21-57 years. In 13 cases, the sleeve gastrectomy was performed as bariatric first intervention. In one case, implantation of gastric banding and removal had preceded. The intraoperative and postoperative criteria were met by all patients. All patients were discharched after 7-12 hrs. The planned outpatient check-ups were made, in-patient admissions were in no case necessary. According to the survey, all of the patients would be ready for an outpatient sleeve gastrectomy again.

Conclusion:
There is an increasing interest of the patients to have sleeve gastrectomy performed on an outpatient basis in Germany. Larger studies, such as in Canada (n = 300 cases) were able to prove the safe practicability of the sleeve gastrectomy in a selected patient population. Unplanned hospitalizations were required in about 10% of cases. Our pilot study proves that, with appropriate patient selection and undisturbed postoperative course, sleeve gastrectomy can be performed on an outpatient basis (up to 12 hours) or in a day surgery concept (up to 24 hours). Bariatric surgery is an integral part in the treatment of obesity. Beside a significant weight reduction, obesity surgery leads to a significant improvement of co-morbidities and quality of life. Surgical procedures are highly standardized while complication rates are very low. The early detection of septic complications is essential in order to be able to react in time if necessary. Furthermore, the safe exclusion of possible complications would be important in allowing patients to be discharged promptly for further outpatient care. Postoperative parameters such as CRP and heart rate are used in everyday clinical practice with still unclear validity.

Materials and methods:
Retrospective analysis of the postoperative course of 617 patients who underwent bariatric surgery at the University Hospital Schleswig-Holstein Campus Kiel between 2007 and 2015. Laboratory and clinical controls were performed on days 1 and 2. C-reactive proteins, leukocytes and heart rate were investigated with regard to septic postoperative complications and the occurrence of staple line leaks and anastomotic insufficiencies.

Results:
In the cohort, 25 patients experienced a staple line leak or anastomosis insufficiency (4%). The ROC curve analysis shows that the CRP value on day 2 is formally very well qualified as a parameter to detect or exclude these complications (AUC 0.858). A sensitivity of 71% and a specificity of 82% could be achieved with a cut off level of the CRP value of 100 mg/l. Heart rate, on the other hand, proved to be unsuitable as a parameter to detect septic complications or insufficiencies (AUC 0.573).

Conclusion:
The use of laboratory parameters such as CRP values is in fact a useful method for identifying septic complications. A high CRP value should increase the attention of the attending physicians and possibly lead to further examinations up to diagnostic laparoscopy. Due to the generally low probability of insufficiencies, however, a positive predictive value of 20% and a negative predictive value of 98% with a 96% probability of uncomplicated courses are not pathbreaking.
An isolated evaluation of individual postoperative parameters for the recognition or exclusion of postoperative insufficiencies after bariatric interventions is not recommended. The clinical view of the treating physician under evaluation of laboratory and clinical parameters is crucial. In bariatric surgery patients, pancreaticobiliary access via endoscopic retrograde cholangiopancreatography (ERCP) is technically challenging. The optimal approach for evaluation and treatment (e.g., of biliary stones) in these patients has been debated. Laparoscopy assisted ERCP (LA-ERCP) as a standard of care and EUS-directed gastroenterostomy (EDGE) or hepaticogastrostomy (HGS) by placement of a temporary lumen-apposing stent as novel techniques have been described.The objective of this study was to evaluate safety and efficacy of three different endoscopic approaches (LA-ERCP and ultrasound (EUS) guided transgastric ERCP) supported by conventional duodenoscope for the treatment of biliary diseases in bariatric patients.

Materials and methods:
In this retrospective review, consecutive patients with Roux-en-Y Gastric bypass (RYGB), Sleeve gastrectomy (SG) or biliopancreatic diversion (BPD) who underwent an LA-ERCP, EDGE or a HGS at a tertiary care reference center for bariatric surgery from 2013 to 2018. Patient demographics, type of procedure and indication, data regarding cannulation and therapeutic intervention of the common bile duct (procedure success) and clinical outcomes were extracted.

Results:
A total of 16 patients were included. Indications for LA-ERC, EDGE or HGS were mostly choledocholithiasis (77%), and in a few cases papillitis stenosans. Eight patients underwent concomitant cholecystectomy combined with LA-ERC. Procedure success was achieved in 100%. Moderate adverse events were identified in 18.7% of patients (all ERC related).

Conclusion:
This case series indicates that ERCP via a transgastric approach (LA-ERCP or EUS-guided EDGE or HGS) is a minimally invasive, effective and safe method to access the biliary tree in patients after bariatric surgery. These techniques offer an appealing alternative way of treatment compared to percutaneous transhepatic cholangiography and drainage or deep enteroscopy assisted ERCP. In bariatric patients who had a cholecystectomy, EUS-guided techniques are the preferred treatment options for biliary indications in our center. Gastrobronchial fistula after bariatric surgery is a rare late complication, whose treatment is very challenging and usually demands an operative and endoscopic approach. Due to a proximate staple line leak which is not sufficiently treated, a chronic subphrenic collection can be formed, resulting in some cases in the break of the diaphragm barrier and evoking in alterations of the respiratory tract.

Materials and methods:
We present three female patients, who underwent a sleeve gastrectomy in external hospitals and were transferred to us in order to treat a proximal staple line leak. Demographics, previous surgeries, clinical presentation, time of the diagnosis of the fistula, treatment methods and outcome were presented.

Results:
All of the patients were female the average age was 32,33 years and the average bmi at the time of the gb fistula was 27. In all patients a laparoscopic sleeve gastrectomy was performed due to morbid obesity with a resulting proximal staple line leak. One patient had undergone a previously mason operation with unsatisfactory results concerning the weight loss. In only one patient a diagnostic laparoscopy to drain the abdominal cavity after the diagnosis of the leak was performed. The average time of the diagnosis of the gb fistula was 14,33 months, although there was a wide range of occurrence from 3 to 36 months. All of the patients showed in the ct scan a fluid selection on the upper left abdominal cavity. In the youngest patient the fluid selection was persistent since the diagnosis of the proximal staple line leak for at least 2 years prior to the the diagnosis of the gb fistula and no further action was undertaken due to lack of symptoms. Productive cough and fever were the two major symptoms. All patients were treated with a combined endoscopic and operativ approachincluding endo vac therapy, endoscopic ballon dilation and fibrin glue as also laparoscopy/laparotomy, abscess drainage (3 patients ) and bypass operation (2 patients), thoracoscopy and thoracotomy with atypical left lower lobectomy. Treatment was successful in one case in 1 month, with a resulting chronic fistula in the other two. No mortalities were reported.

Conclusion:
Gastrobronchial Fistula is a severe mostly late complication after sleeve gastrectomy. In our series a combination of both endoscopic and operativ approach was needed in order to initiate the healing process. The late time of the diagnosis usually results in a prolognated hospitalization.

Background:
Indications and long-term outcome of biliopancreatic diversion with duodenal switch (BPD-DS) in older adults suffering from super obesity remain controversial. The aim of this study was to evaluate safety and long-term outcomes of this bariatric procedure in older patients with super obesity.

Materials and methods:
Patients aged >=60 years who underwent (BPD-DS) between January 2001 and December 2011 were included and had at least 5 years of follow-up. This is a single-center retrospective study of a prospectively collected database (University Hospital, Switzerland).

Conclusion:
BPD-DS is safe and effective in improving obesity-related comorbidities in older patients suffering from super obesity. Age alone should not preclude older patients from getting the best bariatric procedure for obesity and its related comorbidities.

Background:
Biliopancreatic diversion with duodenal switch (BPD-DS) is considered to be one of the most effective bariatric procedures resulting in a sustainable long-term weight loss and a high remission rate of obesity-related comorbidities. Besides its excellent long-term outcome, BPD-DS can lead to severe diarrhea and micronutrient deficiencies in the long-term based on the malabsorptive character of the procedure. Therefore, the risk for secondary hyperparathyroidism due to malabsorption needs to be determined in this population.

Materials and methods:
Data from all 246 patients undergoing BPD-DS between January 2001 and December 2011 were prospectively collected (University Hospital, Switzerland). Life-long micronutrient supplementation consisted according to the American Society for Metabolic and Bariatric Surgery (ASMBS) guidelines of a multivitamin-mineral supplementation on a daily base covering 200% of the daily value. It contained 2'000 IU of vitamin D3, and 2'400 mg of calcium.

Results:
Of all 246 patients, 195 (79.3%) had at least 5 years of follow-up. The majority of the procedures were laparoscopic. Almost all patients (168/195; 86.2%) underwent a concomitant cholecystectomy. Mean age and BMI were 42.8±9.2 years and 48.3±9.1kg/m2, respectively. Average follow-up time after BPD-DS was 85.8±35.9 months. Of 195 patients, 102 (52.3%) showed laboratory signs of a secondary hyperparathyroidism during the follow-up. Although vitamin D levels improved with increased vitamin D3 supplementation in 2007, the rate of secondary hyperparathyroidism increased.

Background:
Super-Superobese patients (BMI higher then 60kg/m2) are of difficult primary bariatric management. Issues regarding exposure and technical difficult anastomosis led to the choice of a 2-stage procedure, usually a sleeve gastrectomy as the first step. In the majority of cases, patients have an unsatisfactory EWL (excess weight loss) after 2 years and high rates still remain in obesity class III.

Materials and methods:
Patients with BMI over 60kg/m2 without esophageal reflux symptomatic were scheduled for a singlestep or two-stage SADI-S procedure. The video describes the technical steps of the procedure, and identified key issues to perform this technique safely. 1. Position: Patient supine, the surgeon stands at the right side to perform sleeve resection, switches to the left side to perform the anastomosis. 2. Six trocars were inserted. 3. The omentum is separated from the greater curvature close to the stomach using harmonic reaching the left crus and sleeve gastrectomy is performed over a 42-Fr Bougie. 4. First segment of the duodenum is stapled. 5. The small bowel loop for the anastomosis is identified going backwards 300cm from the ileocecal junction. 6. Anastomosis is performed in a 2 row fashion or using linear stapler. A drain is placed for the duodenal stump.

Results:
SADI-S was performed in this selected group of patients and the technical issues were identified. The anastomosis can be performed using the linear stapler when possible, or a two-layer hand sewing suture. Covering the sleeve staple line with a synthetic, bioabsorbable staple line reinforcement tissue is advised to avoid staple line complications.

Conclusion:
This new technique is a promising option in our surgical armamentarium to provide effective therapy for obesity patients classified as super-superobese. In the literature, performing SADI-S as a single procedure showed better EWL than patients submitted to 2 stage procedures.

Background:
Infectious complications are the most important cause of perioperative morbidity and mortality after obesity and metabolic surgery. Immediate diagnosis and therapy are mandatory to improve patients' outcome.
The aim of this study was to analyze whether C-reactive protein (CRP) and leucocyte count (LC) are prognostic markers of infectious complications.

Materials and methods:
Patients who underwent laparoscopic sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB) or One anastomosis/Mini-gastric bypass (OAGB/MGB) as primary treatment for severe obesity were included. CRP in mg/l and LC in x10³/ µl were measured preoperatively, on postoperative days 1 (POD 1) and 4 (POD 4). The patients were retrospectively divided into an uncomplicated group and into an infectious group. Latter was defined by postoperative infectious complications according to the Clavien-Dindo Classification.

Conclusion:
Both, CRP and LC increased postoperatively, but only CRP showed a significant difference between the complicated and uncomplicated group. Only a high CRP is predicative of infectious complications. A CRP >= 94.5 mg/l on POD 1 or >= 149.5 mg/l on POD 4 is highly suspicious of leakage and should prompt immediate clinical action.

Background:
Minimally invasive single port surgery was associated with large incisions up to 2-3cm, complicated handling due to the lack of triangulation, and instrument crossing. Aim of this prospective study was to perform true singleport surgery (cholecystectomy) without the use of assisting trocars using a new surgical platform that allows for triangulation incorporating robotic features and to measure the perioperative outcome and cosmetic results.

Materials and methods:
The new technology has been introduced to our academic center as first European site after FDA and CE clearance. In patients with cholecystitis and cholecystolithiasis, the operation is performed through only one 15mm trocar. For patients safety, intraoperative cholangiography using intravenous ICG and a standard Stryker 1588 5mm camera was performed.

Conclusion:
This is the first human case series using the SymphonX platform for abdominal surgery without assisting instruments.
Laparoscopic cholecystectomy in patients with cholecystitis and cholecystolithiasis using the symphonx platform through only one 15mm trocar is feasible and safe. The cosmetic result is promising. Further recruiting of patients for validation of the new technology is necessary and ongoing.

Uniklinik Köln
Background: Minimally invasive technologies have improved outcomes after esophagectomy and the use of robotic technology in Europe is rapidly increasing. Aim of this study is to evaluate the introduction of new technologies in a center of excellence for upper gastrointestinal surgery.

Materials and methods:
A standardized teaching protocol of a complete OR team was performed in simulation and animal models at the center for the future of surgery (San Diego, CA) and IRCAD (Strasbourg, France) to receive certification as console surgeons. Starting 02/2017 the davinci xi and stryker ICG laparoscopy systems were introduced at our academic center (certified center of excellence for surgery of the upper gastrointestinal tract, n>300 esophageal cases/year). After simple training procedures based on our minimally invasive expertise were performed, difficulty was increased based on a modular step up approach to safely perform robotic assisted Ivor Lewis esophagectomy.

Results:
From 02/2017 -09/2018, a total of 50 upper gastrointestinal robotic cases including 30 esophagectomies for cancer were performed. All cases were performed safely without operationassociated complications. Level of difficulty was increased based on our modular step up approach without quality compromises. Video documentation using the new technology is provided and two anastomotic techniques are presented.

Conclusion:
The standardized training protocol and our modular step up approach allowed safe introduction of the new technology used. All cases were performed safely without operation-associated complications.

Background:
Robotic adult general surgery is confined to specialist centres. It is seen as a significant future development of surgery. However, it has cost implications, potential patient benefits are unclear and there are medico-legal implications with a new technique when there are established data on outcomes with open surgery. We sought to determine what factors attribute to the learning curve for robotic surgery.

Materials and methods:
Numerous studies evaluated surgeons learning curves from 1999-2018 in robotic in colorectal, bariatric, biliary and solid organ surgery (right/left hemicolectomy, pancreatectomy, cholecystectomy). A total of ten studies were included describing potential factors impacting surgeons' learning curves.

Results:
The studies demonstrated that there is a significant learning curve in the performance of robotic general surgery, especially during the first 20 patients.
One study showed that users with more than 20-hours of experience performed significantly better in a robotic training model than novices with less than two hours of experience, independent of prior experience.
One study demonstrated a significant time reductions of robotic hemicolectomy time during the first ten cases to a 50% decrease after 30 cases (P=0.001).
Three studies mentioned the importance of stepwise training programmes and simulators in the development of robotic skills.

Conclusion:
Significant learning curve improvements are achieved within the first 20 cases. The training of young surgeons in simulated scenarios and in a stepwise fashion can avoid the complications encountered during the introduction of robotic surgery.

Background:
Anastomic insufficiency results in high morbidity and mortality after esophagectomy and is therefore challenging surgeons worldwide. This is not merely due to technical difficulties regarding surgical experience and anatomical accessibility, but rather a consequence of the ambiguity regarding anastomic blood supply and healing tendencies. Hence, we present the development and usage of augmented hyperspectral imaging (AHSI) as well as first results of its application in esophagectomy.

Materials and methods:
The TIVITA™ tissue system Hyperspectral Imaging (HSI) Camera was used in a porcine model. An esophagectomy was performed in minimally invasive technique, but with open approach for reasons of standardization. After laparotomy, a gastric conduit was formed with linear staplers. Through small incisions magnets were inserted into the conduit. The size and position of these magnets were identical to the linear stapler that is usually used for the thoracic anastomosis (Fig.1f) and they allowed for reversible ischemia evaluation.
For the purpose of this study, the O2 saturation index was measured. Conventional HSI -lacking any harmful radiation or contrast agent -was combined with fluorescence-guided surgery (FGS) in that additional dyes such as indocyanin green (ICG) were applied in order to gain extended tissue evaluation through AHSI. The coding language Python enables to calculate dye-specific indices beyond conventional HSI. In order to correlate the obtained graphical data to clinical outcome, lactate and lactate dehydrogenase -as marker for ischemic areas -were quantified in blood samples drawn from corresponding regions.

Results:
There are 2 hypotheses regarding the blood supply of the gastric conduit. Hypothesized blood supply type I is trans-mucosal. Consequently a wider gastric conduit and a rather aborally stapling position (>3 cm to oral margin) would be beneficial (Fig.1b). Hypothesized blood supply type II is trans-arterial (A. gastroepipl. dextra), traveling sideways from the curvatura major towards the former curvatura minor and resulting in the opposite conclusion (Fig.1c).
After 2 minutes of artificial ischemia, O2 saturation dropped significantly on the left side of the magnets. Further insights exceeding this abstract also support a trans-arterial supply. These preliminary results in 4 animals will be evaluated in continuation with a larger number of experimental studies.

Conclusion:
Blood supply of the gastric conduit is mainly provided through the A. gastroepiploica dextra and advocates for a thin gastric conduit with an aborally linear stapling position for esophageal reconstruction.

Background:
The medical sector is an innovative field in which progresses are made every day. In conventional 2D laparoscopic surgery surgeons often struggle with the disadvantage of a loss of depth perception. The growing development of 3D laparoscopic equipment and the industry who advertise the advantages of the new method lead us to the important question if the 3D technique is superior to the conventional 2D systems. We wanted quantitatively compare the effects of a 3D sight with the conventional 2D laparoscopic optics with regard to the potential benefits of the factors time and manual surgical performance.

Materials and methods:
For this prospective study we used the dV Trainer of Mimic Technologies, Inc. One group of 25 participants who passed three exercises with six repetitions, three with 3D technique and three with 2D optics. The participants were randomized to start either with 3D optics or 2D technique and alternating the optics between 3D and 2D after every exercise. At the end of the exercise the Computer of dV Trainer gave us an evaluation of the completed exercise. This evaluation included the important factors time (in seconds), economy of motion (in centimeters) and master workspace range (in centimeters) and other factors, these were includes in the calculation of the Overall Score. We used the Overall Score for the valuation of the participant´s performance.

Results:
The results showed a superiority of the new 3D technique over the conventional 2D system. The exercises were performed faster, with less problems regarding instrument collisions or instruments out of view and with a better manual performance. The Overall Score was significantly higher with 3D optics than with 2D (exercise Pick and Place p 0.0023, average 2D 742,26, average 3D 885,33; exercise Ring Walk p 0.00052, average 2D 443,53, average 3D 567,05; exercise Stacking Challenge p 0.0008, average 2D 33,43, average 3D 46,38).

Conclusion:
Similar to other publication our results showed a superiority of the 3D technique over 2D conventional laparoscopic optics. However past studies about the new technical progresses with 3D laparoscopic optics, including our own study, had a limited number of participants. The results of this study can be seen as a first step of the evaluation of new systems, however studies with larger populations of participants, with different qualifications, are necessary for a correct and reliable outcome. Cost pressure in the medical sector requires new strategies to economize surgical procedures. Robotic camera steering devices (RCSDs) are designed to replace the human camera assistant in minimally invasive procedures and thus might facilitate "solo surgery". Clinical experience shows that standard laparoscopic procedures can safely be performed as solo-surgery aided by RCSDs. More and more hospitals reduce surgical staff during nights or on weekends and might start using RCSDs to perform exploratory laparoscopies solo. Most RCSDs require active steering by the surgeon and necessarily increase workload. No evidence exists concerning exploratory or emergency procedures with RCSDs.

Materials and methods:
45 novice participants were trained according to the FLS-curriculum before entering the study and then were randomized into two groups. We compared the performance during "exploratory" laparoscopic tasks on box-trainers aided by an RCSD controllable by head-movements or by human camera assistants.

Conclusion:
These results, obtained on surgical simulators indicate, that the solo-approach to standard surgical tasks, facilitated by an RCSD controllable by head-movements can most likely be viewed as safe. Exploratory procedures with a relevant chance for complications or procedures that require rapid and complex camera movements should rather be performed with a human camera assistant. We present and discuss technical advances with the novel bottom-to-up robotic right colectomy plus CME utilizing suprapubic port placement on the basis of a video presentation.

Materials and methods:
Using a representative example of the procedure advances and pitfalls of the technique will be highlighted based on our experience with 25 consecutive cases performed with this robotic technique of RC. The 4-step of the procedure facilitate a dissection guided by embryonal planes rather than searching those planes as will be become clear in the course of this video presentation.

Results:
The substrate for improvements with the presented approach including oncological aspects like enhanced yield in lymph nodes if contrasted to classic medial to lateral approach will be imparted.

Conclusion:
The here presented standardized robotic four-step approach of RC combined with CME may bear the potential of exceeding a minimal invasive technique of RC from the stage of ' being easier than laparoscopy' to an oncological advanced concept.

Landesklinikum Wiener Neustadt
Background: Transoral (para-)thyroid surgery was first described by German study groups. Meanwhile and optimized Transoral Endoscopic Vestibular Approach (TOETVA) has been implemented by Anuwong. We report on our two year experience in Austria and Germany and will present a video of the minimally invasive technique.

Materials and methods:
TOETVA was implemented by our Austrian German study group in June 2017 supported by Dr.
Anuwong. Ince then we operated on patients with single thyroid nodules, sporadic primary hyperparathyroidism or thyroglossal duct cyst. TOETVA was performed using 3 laparoscopic ports, laparoscopic instruments and ultrasonic or bipolar devices inserted at the oral vestibule. Surgical outcome and complications were evaluated.

Results:
Until now, no conversion to open surgery was necessary. Average tumour size was 2.1cm. Temporary hoarseness occurred in two patients. No mental nerve injury occurred. Transient hypoparathyroidism was evident after successful parathyroidectomy and in one patient after thyroidectomy. 15 patients developed a slight postoperative chin hematoma. No infection occurred.

Conclusion:
TOETVA is feasible and safe. The transoral approach shows promise for patients who are motivated to avoid a visible neck scar. After successful implementation in Austria and Germany further transoral operations are destined in selected patients.

Evangelisches Klinikum Bethel, Bielefeld
Background: Several studies have demonstrated a direct correlation between lymph node yield and survival after colectomy for cancer. Complete mesocolic excision (CME) in right colectomy (RC) reduces local recurrence but is technically demanding. Here we present and discuss technical advances with bottom-to-up robotic right colectomy plus CME utilizing suprapubic port placement and compare results to the classical medial-to-lateral approach.

Materials and methods:
32 consecutive patients (median age 75y (51-90y)) following robotic right colectomy with oncological intention to treat and admitted at our center from 5/2016 to 8/2018 were analysed in this retrospective study. Surgery was realized with the DaVinci Xi® system placing the 4 robotic trocars in suprapubic position along a horizontal line plus 1 assist trocar in the left lateral abdomen. Patients were divided in group A with medial-to-lateral (n=7) and group B with bottom-to-up approach (n=25). In group A the right colon was initially dissected on the fascia of Toldt after incision of the peritoneum at the origin of the right mesocolon medial of the supra mesenteric vessels followed by transection of the ileo-colic vessels plus lateral dissection of the peritoneal fixation of the coecum and descending colon. In group B, we applied the novel robotic 4-step bottom-to-up approach of RC guided by embryonal planes in the process of retrocolic mobilization with suprapubic port placement. In step 1 CME was initiated with caudolateral mobilization of the right colon between the retrofascial and the mesofascial interface following Toldt's fascia continued ventral of the duodenum and up to the Trunk of Henle. Subsequently, dissection was performed down-to-up right of the middle colic vessels with central vessel ligation (CVL) in step 2. Latter was eased by the orthograde view along the super mesenteric vessels. Subsequent to separation of the transverse retromesenteric space and mobilization of the hepatic flexure in step 3, the transverse mesocolon was transected right of the middle colic vessels in step 4. Ileo-transversostomies were performed in all cases side-to-side extra corporeally via the incision for specimen extraction in the left upper quadrant.

Results:
The two groups were comparable concerning age, co-morbidity (ASA), operating time, mayor complications, ICU and hospital stay respectively. We experienced no mortality, anastomotic leak or conversion in this patient cohort. We observed 1 trocar-incisional hernia and 1 post-OP blood-infusiondependent anemia in each group, latter without relevant intra-or post-OP blood loss. 2 wound infections and 1 transient chylus fistula developed in group B. The yield in lymph nodes was superior in the bottom-to-up-group with a median of 34,0 nodes (14-86) in comparison to the medial-to-lateralgroup with 14,0 nodes (9-29; p=0,002).

Conclusion:
The here presented standardized robotic four-step suprapubic approach combined with down-to-up mesocolic mobilization and subsequent CME plus CVL demonstrated to be safe even in rather elderly patients. The utilization of robotic systems in the bottom-to-up-technique may not just target a simplification of the minimally invasive procedure of RC. It may bear the potential of exceeding a Abstracts -DGCH Annual Congress 2019-Munich, March 26-29 • DOI 10.1515/iss-2019-2001 s122 Innov Surg Sci 2019; 4, (Suppl 1): s1-s205 minimal invasive technique of RC from the stage of ' being easier than laparoscopy' to an oncological advanced concept especially if compared to the ' classical' medial-to-lateral strategy. Robotic systems may provide the technical requirements to combine advantages of both open and minimal invasive surgical concept in oncologic RC.

Picture:
4 key steps in robotic RC with bottom-to-up-dissection, CME and CVL (left) and here relevant layers and structures of the retro-mesocolic space. Resplenectomy is most commonly done for treatment of recurrent idiopathic thrombocytopenic purpura (ITP) refractory to medical management due to regrowth of a missed accessory spleen.

Materials and methods:
The clinical course of a 66 year old male who had undergone open splenectomy for traumatic rupture 40 years ago and developed a nodule close to the left adrenal gland while receiving chemotherapy including docetaxel/gemcitabine, pazopanib, eribulin, temozolomide, doxorubicin/olaratumab for metastatic leiomyosarcoma is described.

Results:
On surveillance CT-scan a 3.5cm mass compatible with a soft tissue tumor was found close to the tail of the pancreas. During laparoscopy dense adhesion of the omentum to the abdominal wall and stomach from his previous splenectomy were divided. The colon was identified, the lesser sack opened through the gastrocolic ligament and the splenic flexure was taken down. Superior and dorsal to the tail of the pancreas next to the left adrenal gland the mass was identified and carefully dissected out. The vascular pedicle, which originated from a side branch of the splenic artery and splenic vein at the tail of the pancreas was stapled. The gastric fundus showed multiple nodules and therefore, a modified sleeve gastrectomy was done; also a 2cm nodule in segment 5 of the liver and an omental nodule were removed. The tumors and gastrectomy specimen were placed into an endobag and removed through a periumbilical miniincision. The patient recovered well from the procedure without any complications. Pathology revealed no sarcoma metastases but accessory spleens in all specimens.

Conclusion:
Re-growth of splenic tissue after splenectomy for trauma is a rare condition but should be considered. This may lead to splenism with multiple implants within the abdomen. In our patient this seems to have been triggered by chemotherapy for his sarcoma resulting in extramedullary hemopoesis. Laparoscopic removal of accessory spleens can be safely done.

Universität für Veterinärmedizin Budapest
Background: Robotic-assisted esophagectomy for cancer has been increasingly employed world-wide, however, the benefits of this technique compared to laparoscopic assisted esophagectomy are unclear. Since 2016, robotic-hybrid (R-HMIE) esophagectomy has increasingly replaced laparoscopic-hybrid esophagectomy (HMIE) as the standard of care in our institution. Aim of this study was to compare these procedures.

Materials and methods:
Over a 24-month period, 199 patients underwent esophagectomy for cancer at our institution. Out of these patients, 51 underwent a robotic-assisted hybrid technique. Each patient was matched according to gender, age, comorbidity and ASA-classification, tumor stage und localization, histology and neoadjuvant treatment with a patient who underwent HMIE. Perioperative parameters and results were extracted from our institutional database and compared among the two groups.

Results:
After the matching-procedure, 88 patients could be included in the study. Between laparoscopic and robotic-hybrid esophagectomy no significant differences could be found in operating-time (median 281 vs 300 minutes), R0-resection rate (n = 42 vs 42), harvested lymph-nodes (median 28 vs 24 nodes), length of hospital (median 19 vs 17 days) and ICU stay (median 7 vs 6.5 days). Regarding surgical complications no difference could be observed either (n = 42 vs 44), nevertheless life-threatening complications (Clavien-Dindo 4 or 5) occurred less frequently after robotic-assisted procedure (n = 6 vs 3). No gastric-conduit necrosis was observed for both groups.

Conclusion:
Minimal-invasive esophagectomy still remains a challenging operation with high morbidity even in a high-volume institution. According to our experience, robotic-hybrid esophagectomy should be considered as a feasible and safe option. It showed comparable results with the laparoscopic-hybrid procedure even after a short learning period.

Background:
Radical esophagectomy for patients with cancer is crucial for achieving prolonged survivals. The role of minimal-invasive esophagectomy (MIE) in comparison to conventional open resection for esophageal cancer or cancer of the gastroesophageal junction needs further investigation.

Materials and methods:
Clinicopathological data of patients who underwent oncologic thoracoabdominal esophagectomy between 2010 and 2017 were assessed. Postoperative outcomes und long-term survivals of patients following MIE were compared with those of patients undergoing conventional open esophagectomy (OE) after 1:1 propensity score matching.

Conclusion:
MIE is associated with lower postoperative morbidity and mortality, resulting in similar disease-free survival rates compared to those achieved with the conventional OE. Our data suggest that MIE should be preferably performed in patients with esophageal cancer or cancer of the gastroesophageal junction.

Background:
Selection of appropriate candidates for upper gastrointestinal (GI) cancer surgery and perioperative management have been increasingly improved in the recent years. However, the impact of medical comorbidities on postoperative and long-term outcomes in patients undergoing resection for gastric or esophageal cancer remains unclear.

Materials and methods:
Clinicopathological data of patients who underwent resection for gastric or esophageal cancer between 2005 and 2015 were evaluated. A classification of comorbidities defined as the Comorbidities Score (CS) was used to facilitate assessment of the risk for increased postoperative morbidity, mortality and diminished overall survival following resection for upper GI cancer.

Results:
Curative resection for gastric and esophageal cancer was performed in 705 patients. Transthoracic esophagectomy, extended gastrectomy, total gastrectomy, subtotal gastrectomy, and the merendino procedure was performed in 45%, 21%, 10%, and 2% of the patients, respectively. CS describes the presence of no (Grade 0), one (Grade A), two (Grade B), three (Grade C), or four (Grade D) concomitant pathologic conditions from different organ systems including cardiovascular, metabolic, pulmonary, renal, and hepatic diseases. Advanced CS was associated with higher complications rates (P =.001) and independently predicted higher major complications rate in multivariate analysis (odds ratio [OR] 1.5, 95% confidence interval [CI] 1.0-2.1, P = .042). However, higher CS did not result in worse postoperative mortality (P = .281). CS was also associated and with a lower rate of patients returning to intended adjuvant systemic treatment (P = .028) and had a negative impact on overall survival (61, 44, 40, and 26 months for CS 0, A, B, and C, respectively, P = .135), even though statistical significance was not reached.

Conclusion:
CS is associated with a higher risk for major postoperative complications following resection for gastric or esophageal cancer and may be used as a prediction tool for intensified patient preparation before surgery. Modern perioperative care protocols and successful management of complications are essential to facilitate completion of multimodal treatment concepts enabling optimum outcome for upper GI cancer.

Background:
Laryngopharyngeal pH-monitoring (Restech) is a relatively new reflux testing device that needs more validation. It was developed to detect both liquid and acidic gas vapor, and the more consistent pharyngeal placement may lead to more reliable results, especially when laryngopharyngeal symptoms such as cough, hoarseness and globus sensation are present. Aim of this study is to determine if Restech can identify patients with a successful outcome for certain symptoms after antireflux surgery.

Materials and methods:
In our esophageal center of excellence, more than 300 esophageal surgeries are performed annually. All patients undergoing minimally invasive or open upper gastrointestinal surgery are prospectively entered in our IRB approved database and undergo a routine check-up program with postoperative surveillance following surgery. All patients with benign disease received a complete diagnostic workup for gastroesophageal reflux including symptom evaluation, endoscopy, 24-hour impedance pHmetry, high resolution manometry and Restech. Only patients with a complete dataset and oropharyngeal reflux symptoms were offered inclusion into this study and evaluated using 24-h laryngopharyngeal and simultaneous esophageal impedance pH-monitoring.

Results:
A total of 155 [99 females] consecutive patients with suspected gastroesophageal reflux disease and oropharyngeal symptoms that were seen between 10/2013 and 08/2018 were included and underwent 24-h laryngopharyngeal with concomitant esophageal pH-monitoring.A total of 24 of these patients with laryngopharyngeal symptoms underwent laparoscopic antireflux surgery from 10/2013 -02/2018 and had a complete follow up. Restech evaluation was abnormal in 62. 5% (n=15,

Conclusion:
An abnormal Restech result better identifies a successful outcome for regurgitation and extraesophageal symptoms after antireflux surgery. All patients had a complete resolution of extraesophageal symptoms after surgery.

Background:
Laryngopharyngeal pH-monitoring (Restech) is a relatively new reflux testing device that needs more validation. It was developed to detect both liquid and acidic gas vapor, and the pharyngeal probe placement may lead to more reliable results in patients with laryngopharyngeal symptoms.A negative Restech result could be used as a screening instrument for gastroesophageal reflux and help decide whether patients should be included into a diagnostic pathway or benefit from a PPI therapy. Aim of this study is to examine the value of negative Restech test results using a large patient collective.

Materials and methods:
In our esophageal center of excellence, more than 300 esophageal surgeries are performed annually. All patients undergoing minimally invasive or open upper gastrointestinal surgery are prospectively entered in our IRB approved database and undergo a routine check-up program with postoperative surveillance following surgery. All patients with benign disease received a complete diagnostic workup for gastroesophageal reflux including symptom evaluation, endoscopy, 24-hour impedance pHmetry, high resolution manometry and Restech. Only patients with a complete dataset and oropharyngeal reflux symptoms were offered inclusion into this study and evaluated using 24-h laryngopharyngeal and simultaneous esophageal impedance pH-monitoring.

Results:
A total of 155 [99 females] consecutive patients with suspected gastroesophageal reflux disease and oropharyngeal symptoms that were seen between 10/2013 and 08/2018 were included and underwent 24-h laryngopharyngeal with concomitant esophageal pH-monitoring.Restech evaluation was negative for reflux (=normal) in 55.5% (n=86, mean RYAN Score upright 2.5 [2.12-8.57], mean RYAN Score supine 2. 2 [2.17-5.86]). In 45.3% of Patients with a normal Restech evaluation, 24-hour pH-metry was pathologic (n=39,). Nearly half of the patients with a normal RYAN and a normal DeMeester Score (n=20) did not complain about heart burn but only oropharyngeal symptoms. No patient with a normal RYAN Score and a normal DeMeester Score underwent antireflux surgery.

Conclusion:
As shown in earlier research, Restech and 24-hour pH do not necessarily need to correspond. More women than men presented with oropharyngeal reflux related symptoms.A negative Restech examination combined with a negative 24-hour pH metry may help to support the decision for or against antireflux surgery but is alone not suitable as a negative screening tool for GERD. Abstracts -DGCH Annual Congress 2019-Munich, March 26-29 • DOI 10.1515/iss-2019-2001s131 Innov Surg Sci 20194, (Suppl 1): s1-s205 Picture: Abstracts -DGCH Annual Congress 2019-Munich, March 26-29 • DOI 10.1515/iss-2019-2001s132 Innov Surg Sci 20194, (Suppl  Patients with peritoneal metastases of gastric cancer have a poor prognosis and median survival of 7 months. This study compared treatment options and outcomes based on the Peritoneal Cancer Index (PCI).

Materials and methods:
This retrospective analysis included patients with gastric cancer treated between August 2008 and December 2017 with synchronous peritoneal metastases only diagnosed by laparoscopy. The three treatments were as follows: 1) cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in combination with pre-and postoperative systemic chemotherapy (n=58), 2) laparotomy/laparoscopy without CRS, but HIPEC in combination with pre-and postoperative systemic chemotherapy (n=11) and 3) systemic chemotherapy only (n=19).

Royal Free Hospital London
Background: Anastomotic leakage (AL) remains a major cause of morbidity in foregut surgery. In many centers, endoluminal vacuum therapy (EVT) after esophagectomy has become the mainstay of therapy for AL after esophagectomy. A novel concept is to use this technology in a preemptive setting with the aim of reducing AL formation and postoperative morbidity.

Materials and methods:
Preemptive EVT (pEVT) was performed in consecutive patients undergoing minimally invasive esophagectomy with cervical (n=1) or high intrathoracic (n=18) anastomosis between November 2017 and July 2018. PEVT was performed during surgery immediately after completion of esophagogastrostomy. Routine sponge-removal was performed three to six (median 5) days after esophagectomy. Records of patients were reviewed with respect to demographic characteristics, oncological parameters, surgical procedures, and the postoperative course up to 30 days after surgery. Endpoints of this study were adverse events related to pEVT, postoperative morbidity and AL rate, defined according to the definitions of the Esophageal Complications Consensus Group (ECCG). The Clavien-Dindo (CD) classification, and the Comprehensive Complication Index (CCI) were used to categorize and grade complications and morbidity.

Results:
There were 20 anastomoses at risk in 19 patients. Mortality after 30 days was 0% and anastomotic healing was uneventful in 19 of 20 anastomoses at risk in this series (95%). One high-risk patient after minimally invasive Ivor Lewis esophagectomy had a minor contained AL that healed uneventfully after a second course of pEVT for 5 days. One patient (5.3%) experienced major morbidity (Clavien-Dindo >= CD grade IIIb) unrelated to anastomotic healing. He required surgical revision with shortening of the gastric tube and open re-anastomosis (with pEVT) after 12 days because of redundancy of the interponate with failure of transition to oral diet. Except early proximal dislodgement in one patient (5.3%), there were no adverse events attributable to pEVT. The median postoperative ICU and hospital stay was 1 (IQR 1-2) and 14 (IQR 11-16) days, respectively. The median CCI at 30 days after surgery was 20.9 (IQR 0-26.2).

Conclusion:
PEVT appears to be a safe procedure that may have the potential to improve surgical outcome, particularly in high-risk patients undergoing esophagectomy. Further research is required to elucidate the true potential of this technique in the preemptive setting.

Background:
Patients with peritoneal metastases of gastric cancer have a poor prognosis and a median survival of 7 months. Recently, patients with extensive metastatic disease treated with intensive intravenous chemotherapeutic regime were not able to exceed a median survival of 11 months. During the last years, the evidence supporting regional application of chemotherapy, especially Pressurized Intra Peritoneal Aerosol Chemotherapy (PIPAC) is growing.

Materials and methods:
This retrospective analysis included patients with synchronous peritoneal metastases of gastric cancer (n=15) treated with PIPAC (Cisplatin: 7,5 mg/m2; Doxorubicin 1,5mg/m2) and alternating two cycles of intravenous chemotherapy (FLOT or second line chemotherapy) between December 2016 and March 2018. The study cohort was compared with a historic cohort of patients (n=16) with synchronous peritoneal metastases of gastric cancer treated with systemic chemotherapy between 2010 and 2016 and diagnosed by laparoscopy at our institute.

Results:
We Perioperative morbidity was low (7.7%) with no reoperation and no intensive care unit admission. Mortality was 0%. Five patients could not complete the suggested three cycles due to tumour progression (n=3 peritoneal; n=1 liver metastases) or massive adhesions (n=1).

Conclusion:
PIPAC with 7,5 mg/m2Cisplatin and 1,5 mg/m2Doxorubicin with alternating two cycles of intravenous chemotherapy is a safe therapeutic regimen with low morbidity and mortality in patients with peritoneal metastases of gastric cancer. This therapy showed significant higher median survival in this retrospective study. Further randomized control trials are necessary to evaluate the effect of PIPAC in these patients.

Background:
Duodenal stump insufficiency is a life-threatening complication in patients who have undergone gastric resection. Treatment of duodenal stump insufficiency is complicated and it is not clear which therapeutic method leads to faster clinical recovery and shortens the length of hospital stay. Aim of the study was to compare the outcomes of duodenal stump insufficiency after treatment with a percutaneous transhepatic cholangiodrainage (PTCD) with surgical intervention.

Materials and methods:
Retrospective analysis of all patients who have developed duodenal stump leakage between January 2007 and June 2018 at the University Hospital of Paracelsus Medical University Salzburg, after undergoing total gastrectomy, Billroth II resection or subtotal gastrectomy. Patients were divided into two groups according to the type of treatment they have received -a conservative group treated with a PTCD and a surgical group treated with a relaparotomy and surgical closure of the duodenal stump. The length of hospital stay and the number of days spent at the intensive care unit after relaparotomy or after becoming a PTCD were analyzed in both groups. Further analysis involved the tracking of CRP value, total bilirubin, aspartat-aminotransferase (AST), alanin-aminotransferase (ALT), gammaglutamyl-transferase (GGT), alkaline phosphatase, amylase, lipase and leukocytes on the day of the intervention (surgery/becoming a PTCD) as well as on the first day, one week, two weeks, and one month after the intervention.

Results:
In the study period 17 patients (9 male and 8 female patients, mean age 67,3 years) developed duodenal stump leakage after surgery. Seven patients were treated with PTCD and ten patients underwent relaparotomy. Mean length of the hospital stay in the group treated with PTCD was 51,7 days and in the relaparotomy group 53,6 days (p=0,904). Mean number of days spent at the intensive care unit in the PTCD group compared to surgical group was 11 versus 23,0 days (p=0,235). Comparison of the tracked blood values showed faster normalization of alkaline phosphatase within the first two weeks with mean value of 138 U/L in the surgery group compared to the mean value of 264 U/L in PTCD group (p=0,040). Also significantly faster normalization of Lipase within the first week was noted in patients after surgery (mean 21,7 versus 82,0 U/L; p=0,004). Comparison of remaining blood values showed no statistically significant differences between the two groups.

Conclusion:
PTCD therapy of duodenal stump insufficiency after gastric resection seems to be the treatment of choice, since it leads, to faster clinical recovery, shorter hospital and intensive care unit stay. Further studies are required to confirm the benefit of conservative therapy in comparison to surgical reintervention for treatment of duodenal stump insufficiency.

Background:
GERD is an important topic since 10-20 percent of the population suffer from its symptomes in Europe and the US. However, its pathophysiology is not totally understood. Few studies suggest that hormones play a role, especially in the motility of the lower esophagus, but data is rare. Furthermore, the reasons for other motility disorders like achalasia is partly unknown. In this prospective study we evaluated the correlation between hormones (TSH, fT3, fT4, calcitonin, gastrin and VIP) and GERD as well as its gastrointestinal symptoms.

Materials and methods:
100 consecutive patients with typical reflux symptoms, atypical reflux symptoms and dysphagia where hospitalized for diagnostic evaluation. Questionnaires to evaluate quality of life (GIQLI) and reflux symptoms (reflux symptom index and symptom check list) were handed out. Patients routinely underwent serum analysis (TSH, fT3, fT4, calcitonin, gastrin and VIP), 24-hours-pH-impendance monitoring and high resolution manometry. After high resolution manometry patients where subdivided into three groups with minor motility disorders, major motility disorders and normal values according to the Chicago classification.

Results:
Complete data was available from patients (male:female 44:42, median age 56). Motility disorders were found in 38 out of 86 patients. A pathological DeMeester was found in 45 patients with median score of 35. There have been no correlations between the DeMeester score and the hormones. Of the 86 patients, the median LES pressure was 23,6 mmHg, but no correlations were found between the different hormone levels and the LES-pressure. But a strong inverse relation between calcitonin and the Integrated Relaxation Pressure (IRP) of the esophagogastric junction (EGJ) was found (r= -0,492; p=0,000). No correlations were found between hormone levels and the mean scores of GIQLI, RSI and SCL. But positive correlations were found between VIP and GI-Symptoms (r=0,298; p= 0,011), as well as correlations between fT3 and dysphagia (r=0,283, p=0,016). Within the group II, TSH and fT4 correlated with outcomes of the SCL-questionnaire. fT4 correlated with the Typical-symptoms (p=0,002), as well as the GI-symptoms (diarrhea, constipation, flatulence) (p=0,039). TSH correlated with the Typical-symptoms (p=0,007). A regression analysis confirmed that these outcomes were no coincidence. Further within group II a correlation between VIP and the SCL-Gas-Bloat-Symptom (p=0,072) was found.

Conclusion:
Few studies and case reports suggest a connection between GERD and hormones. We found no correlation between TSH, fT3, fT4, gastrin, VIP and calcitonin and GERD, though, calcitonin seems to have an effect of the lower esophageal sphincter. Further studies need to be done to evaluate the role of hormones in motility disorders of the upper GI. In laparoscopic total gastrectomy, esophagojejunostomy using a circular stapler has become the preferred method. However, placing a purse-string suture in the distal esophagus and inserting an anvil is a technically demanding procedure. Conventional laparoscopic assisted total gastrectomy (LATG) need an auxiliary incisionfor esophagojejunostomy sometimes this incision is not too small. Totally laparoscopic total gastrectomy (TLTG) is a very difficult operation for the difficulty associated with esophagojejunostomy during this procedure without auxiliary incision. Although several techniques have been reported to overcome this issue, a reliable technique hasnot yet been established. We successfully performed intracorporeal esophagojejunostomy using a complete handsewn reconstruction, and have shown its favorable outcomes compared with those of conventional laparoscopic assisted total gastrectomy. Here we describe our technique in the video.

Materials and methods:
After transection of the esophagus, a complete hand-sewn reconstruction was performed, first all seromuscular layer suture jejunum to esophagus at the left side and right side with 3-0 antibacterial suture, then suture bowl and esophagus full-thickness with a 3-0 bidirectional barbed wound-closure device completely with hand-sewn. When sew the posterior wall from the left to the right side of the cut end in an inside-to-inside direction, and then sew the anterior wall from the right side to the left side in an outside-to-outside direction. Finally, intracorporeal esophagojejunal anastomosis was performed using hand-sewn.

Results:
In totally laparoscopic total gastrectomy, reconstruction using this method was performed for 13 patients with gastric cancer. There were no serious intraoperative complications, one case need conversion to open surgery. There were no anastomotic leakage and stenosis occurred. The meantime for esophagojejunal anastomosis was 43 min for the 12 patients who received complete hand-sewn successfully.

Conclusion:
The advantage of this technique is economical from omitting of stapler. And it is more minimally invasive without auxiliary incision. Complete hand-sewn esophagojejunal reconstruction in totally laparoscopic total gastrectomy is safe and feasible with minimal invasiveness.

Klinikum Rechts der Isar der TU München
Background: The validity of the eighth edition of the UICC staging system for gastric cancer has been evaluated only in Asian cohorts, and not reported in European cohorts so far. The aim of this study was to evaluate the prognostic performance of the eighth edition UICC staging system in both German and Korean cohorts.

Materials and methods:
A total of 6,121 (526 from Germany, 5595 from Korea) patients treated for gastric cancer were reclassified according to the eighth edition. Survival according to the UICC stages was estimated by the Kaplan Meier method and compared with log-rank tests. A Cox proportional hazards model was fitted adjusting for demographic and clinicopathological factors, and ROC analysis was conducted.

Results:
The German cohort had different characteristics in age, tumor size, location, Lauren classification, stage, and type of surgery compared to the Korean cohort. The eighth edition staging system did not provide significant survival differences between each adjacent stage in the German cohort, but did in the Korean cohort. Multivariate analyses revealed that the eighth edition staging system was an independent prognostic factor and C-statistics were greater than 0.78 in both German and Korean patients. The results were comparable to the UICC seventh edition. (C-statistics: 0.768 vs. 0.767 in the German, and 0.789 vs. 0.785 in the Korean cohort for seventh vs. eighth edition).

Conclusion:
The eighth edition UICC staging-system showed prognostic value in predicting survival of gastric cancer patients in both German and Korean cohorts. However, the predictive ability of the eighth edition was similar to that of the seventh edition in both cohorts.

Background:
Anastomotic leakage is the most important surgical complication following esophagectomy for esophageal cancer, leading to increased morbidity and mortality. A major cause of leakage is impaired healing due to ischemia of the gastric tube that is used for reconstruction of the gastrointestinal tract. A possible therapy option for such patients, but also for high-risk patients due to other comorbidities, is the two-stage esophagectomy with ischemic conditioning. The benefit of this individualized therapy is currently under discussion. The aim of this retrospective analysis was to summarize possible indications for a two-stage esophagectomy and to present its outcome.

Materials and methods:
Clinical data of all patients who underwent a two-staged esophagectomy for esophageal cancer between 05/2016 and 04/2018 were reviewed. Two-stage esophagectomy consists of a laparoscopic gastric mobilization with partial devascularisation and an open transthoracic esophagectomy with intrathoracic reconstruction (hybrid Ivor-Lewis esophagectomy) after an interval of 4-5 days. Comorbidities, indication for the procedure as well as short-term outcome were recorded and anylysed by using SPSS (version 25). Complications were defined according to ECCG criteria and classified according to Clavien-Dindo (CD).

Conclusion:
Two-stage esophagectomy is a feasible and safe surgical procedure for patients with increased risk of postoperative complications due to a high number of comorbidities. Postoperative complication rates are comparable to recently published large registry data (,ESOData benchmarking').

Background:
Gastroesophageal Reflux Disease (GERD) has a high prevalence in bariatric patients. Whilst 85% of patients with preoperative GERD after Roux-Y Gastric Bypass (RYGB) are symptom-free, sleeve gastrectomy (SG) as the most commonly performed bariatric procedure results in considerable de novo GERD and may worsen preexisting GERD.
Given the absence of anatomical abnormalities, options in patients with persistent GERD after RYGB are limited. Further, post-SG patients do not have good treatment options except for more invasive, anatomy-altering conversion to RYGB.
Neuromodulation of the esophagus has shown to improve outcomes in GERD patients. Consisting of an implantation of two electrodes beneath the lower esophageal sphincter, it respects the anatomy, improves lower esophageal sphincter pressures and esophageal motility.
This study evaluates the efficacy of esophageal neuromodulation in postbariatric patients with GERD not controlled under maximum dose PPI therapy.

Materials and methods:
Data of all consecutive patients undergoing implantation of an EndoStim-system (ES) in a postbariatric setting a university hospital were recorded in a prospective computer database and reviewed retrospectively. Preoperative GERD evaluation consisted of questionnaires, gastroscopy, upper GI series and functional esophageal testing with 24h-pH-impedance-manometry. Postoperative evaluation included questionnaires, gastroscopy after 1 year and 24h-pH-impedance-manometry after 9 months.

Results:
15 patients post-SG and 4 patients post-RYGB underwent implantation of ES. Mean follow-up was 1.8 y.

Conclusion:
Neuromodulation of the esophagus results in a significant improvement of GERD-symptoms and esophageal pH-exposure, both in patients after SG and RYGB. It provides a valid option to address GERD without the need to alter the existing anatomy.

Background:
Esophageal and gastric cancers usually occur at a higher age, and patients often present significant comorbidities. In combination with the risk profile of esophageal and gastric cancer surgery, the preclinical condition is relevant for morbidity and mortality after esophagectomy and gastrectomy. We aimed with the current project to investigate if postoperative physical recovery is as well significantly affected by preclinical conditions of the patient, and whether the patients' condition might be a surrogate for the need for extensive rehabilitation.

Materials and methods:
We conducted a retrospective study on 108 consecutive patients that underwent esophagectomy (n=56) or gastrectomy (n=52) between 2013 and 2017. We analysed the impact of patients' condition, tumor stage and treatment and complications on ICU time, respirator time, physical recovery in hospital and discharge conditions.

Conclusion:
Preoperative patients' condition seems to have no significant impact on recovery after esophagectomy of gastrectomy. However, complications affect recovery negatively.

Background:
Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors, representing 1-3% of all gastrointestinal cancer. Surgical resection is the only curative treatment. Minimally invasive approaches such as laparoscopic and robotic-assisted resections for gastric GIST have proved to be oncologically and surgically safe. We report here a case series of robot-assisted gastric GIST resections.

Materials and methods:
We performed a retrospective analysis of all gastric GIST resected between 2007 and 2018 in our center.

Results:
19 patients underwent robot-assisted gastric resection for GIST, 12 females and 7 males. Median age was 59 years (range 38-79) and median BMI was 27.5kg/m2 (range, 18.6-41.3). Median tumor size was of 5 cm (range, 1.8-9). 13 were on the posterior wall and 7 were proximal (fundus or cardia). All tumors were completely resected (R0). We noted one conversion to open resection because of a positive margin requiring a radical resection. Median operative time was 163 minutes (range, 90-436). We reported no postoperative complications within 90 days after surgery. The median follow-up was 8 months (range, 1-115) and we reported no oncological recurrence.

Conclusion:
Our case series confirm that robotic-assisted resection is safe and offers the same oncological results as the others approaches (open and laparoscopically) for gastric GIST.

Universitätsklinikum Erlangen
Background: Existing research recognizes the critical role played byAnatomic leakage (AL) of Esophagojejunostomy after total gastrectomy, to be one of the most severe complications, as it has accentuated the problem of significantly prolonging hospital stays, and thereby, increasing the mortality rate. Recently, the concern for evaluating post-operative complications have gained substantial importance with the increased survival rate of patients after gastrectomy. Therefore, this study aims to assess the correlation between the different sizes of the circular stapler and the rate of Anastomotic leak.

Materials and methods:
Through our retrospective analysis, we have conducted an investigation on 391 Patients with Gastric Cancer who underwent total gastrectomy, which focuses on the influence of the circular stapler size 21/25 mm (Group 1) compared to 28/29 mm (Group 2) in terms of the postoperative rate of Anastomotic leakage

Results:
Clinical anastomotic leakage was compared in (Group 1= 21/25mm) of 169 Patients to (Group 2=28/29mm) of 222 Patients. The leakage incidence was 8.9 and 4.1 % respectively. Therefore, the stapler size 28/29mm had statistically significant impact on reducing the rate of AL.

Conclusion:
The application of the 28/29 mm circular stapler size for the Esophagojejunostomy in the total gastrectomy operations shows significant lower rates of AL, and thereby, the association between the size of the stapler and the rate of AL exists.

Background:
Patients after liver transplantation (LT) have an increased risk for malignancies. This includes tumors of the upper gastrointestinal tract. We identified and analyzed all patients who developed a tumour of the upper gastrointestinal tract after perceiving LT at our institution. Aim of this study is to describe the characteristics of the affected patients and the outcome after therapy.

Materials and methods:
Between 1988 and July 2018 2855 LTs were performed at Charité Campus Virchow-Klinikum. All patients with diagnosed esophageal or gastric cancer after LT were identified. We analyzed the type of tumour, staging, grading, oncological as well as type of surgical therapy and survival.

Results:
A total of 23 patients developed a tumour of the upper gastrointestinal tract after LT. In the LT cohort the male ratio was 60.1% while LT patients with upper GI tumors were all male . In 22 cases LT had been necessary due to alcoholic cirrhosis, 6 patients had HCV-coinfection and one patient showed an additional α1-antitrypsin deficiency. The only patient without alcoholic cirrhosis suffered from cryptogenic cirrhosis. In the complete LT cohort alcoholic cirrhosis was found in 21.8% of patients. The mean age at the time of the LT was 52.9 years (CI 39-61 years). The mean age at time of cancer diagnosis was 61.8 years (CI 55.9-67.3). 20 patients suffered from esophageal cancer, while three patients developed gastric cancer. 15 tumours were squamous cell carcinomas, six adenocarcinomas and one tumour of neuroendocrine origin. All of these cases were diagnosed in an advanced UICC stage (III or greater) of which seven were in metastatic stage IV. 14 patients received therapy including radical surgery. Ivor Lewis esophagectomy was performed in 10 cases. One patient received McKewon esophagectomy and three patients underwent gastrectomy. The average survival after cancer diagnosis was 39 months (CI 7.7-70.7). Patients who underwent surgery showed a prolonged survival, lasting on average 50 months (CI 5.0-94.8), whereas patients with conservative treatments survived on average 17 months (CI 8.3-25.8).

Conclusion:
The 23 surveyed patients with tumours of the upper gastrointestinal tract after LT were all male. Another risk factor is alcoholic liver disease affecting 22 of 23 patients. The incidence of upper GI tumors is strongly elevated among LT patients. Outcome is slightly improved in the surgery group with few patients showing long time survival. A more aggressive endoscopy program for LT patients should be implemented to diagnose tumors at an earlier stage. Hereditary Haemorrhagic Telangiectasia (HHT) is a rare autosomal dominant disorder. Clinical diagnosis of HHT is based on at least three out of four Curacao criteria: 1) spontaneous or recurrent epistaxis 2) multiple telangiectasia especially in the lips, oral mucosa, fingers and nose 3) visceral arteriovenous malformation and 4) positive family history (first-degree relative).

Materials and methods:
We report of a 72-year old female suffering from HHT undergoing orthotopic liver transplantation (OLT). Preoperatively, the patient's left-right shunt due to extensive arteriovenous malformations in the liver and concomitant pulmonary hypertension (PHT) were of great concern, raising discussions about the adequate indication for OLT.

Results:
Five years prior to OLT, the patient was diagnosed with increasingly symptomatic PHT "associated with" HHT. Over the years, PHT turned from mild to severe and the patient started developing cardial cachexia with 11kg weight loss in 7 months. Preoperative right heart catheterization yielded a mean PAP of 49mmHg and PCWP of 14mmHg. Medical treatment included Sildenafil (3x10mg) and Lecardipin (1x5mg). PHT remained stable under this treatment but the patient necessitated repeated hospitalization due to sepsis with extensive biliary liver abscesses, the largest being 7.5cm in segment VII. The patient underwent several ERCP and stent placements for extensive choledocho-and hepaticolithiasis with both abnormally dilated and stenotic bile ducts. In time, biliary outflow of the right (posterior) bile ducts was only ensured via a biliary-cutaneous drainage. In an interdisciplinary approach, OLT was evaluated as the only treatment option with a reasonable success rate to overcome the increasingly problematic persistent infectious complications due to bile duct degeneration and vascular compromise.
During the operation the patient's liver showed classical signs of very extensive intrahepatic arteriovenous shunts with massive, multiple arteriovenous collaterals in the liver hilum. The common hepatic artery and an accessory left hepatic artery were of impressive diameter, with substantial blood flow. Following dissection and ligation of the hepatic arteries, PHT resolved almost instantly. OLT was carried out in standard piggy-back technique. The intra-and postoperative course was uneventful, in particular without reoccurrence of any infectious complications.

Conclusion:
This case clearly shows that OLT solves rather than complicates concomitant pulmonary hypertension in patients suffering from HHT. Initial doubts arose as to whether or not she would even qualify for OLT due to severe PHT in the setting of her HHT. However, with no other feasible treatment options and taking into account, that the majority of her PHT would likely resolve after removal of her old liver with the intrahepatic arterio-venous shunts, an interdisciplinary decision was taken to go ahead with the transplant. The very favourable outcome with a now completely asymptomatic patient (no PHT and no infectious problems) shows, that the decision to transplant was justified.

Universitätsklinikum Jena
Background: Tumor recurrence is the most frequent cause of death after liver transplantation for hepatocellular carcinoma. We selected ten other prognostic classifications to evaluate their potential to predict the risk of recurrence after LT for HCC as compared to the Milan classification. All of the other scores have not been compared one with another in a single cohort.

Materials and methods:
Data of 147 consecutive patients transplanted at our department between 1996 and 2014 were analyzed and staged for morphological and functional scores of underlying liver disease. For long-term follow up, we analyzed separately intrahepatic (within the liver ± distant metastases) and extrahepatic (distant metastases only) recurrence.

Results:
The median survival time for all patients was 106 months. The 5-and 10-year observed survival rates were 61% and 43%, respectively. The observed cumulative 5-and 10-year recurrence rates were 37% and 39%, respectively, 10-year intrahepatic and extrahepatic recurrence rates were 12% and 27%, respectively. Median survival time after diagnosis of first recurrence was 7.5 (0-120) months; 2 months and 18 months for all, intra-and extrahepatic recurrence, respectively.

Conclusion:
UCSF-, Up to seven-, Shanghai Fudan-or Duvoux-classifications can identify patients with a cumulative 10 year recurrence rate below 20%. The pre-therapeutic AFP level should be considered in addition to the geometry of the intrahepatic lesions. Cathepsin S is involved in peptide loading to the MHC class II and thus important for antigen presentation. CatS can also be secreted by activated macrophages and neutrophils and activates protease-activated receptor-(PAR)-2 on the endothelial cells. We hypothesized that targeting CatS/Par2 would have a dual suppressive effect on kidney allograft rejection by limiting alloantigen presentation as well as vascular damage.

Materials and methods:
Murine kidney transplantation was performed in the syngeneic (B6 to B6) and allogeneic setting (Balb/c to B6). Mice were either treated with CatS inhibitor or vehicle. To study the effects of Par2 deficiency, we performed kidney transplantation using C57BL/6.Par2-/-. Therapeutic effects were assessed by histopathology, immunohistochemistry and RT-PCR.

Results:
At 10 days allografts showed severe acute rejection with strongly induced mRNA levels of CatS and numerous inflammatory genes. CatS inhibition significantly ameliorated the acute rejection process. Immunostaining showed suppressed CD8 cell infiltration into grafts, reduced mRNA expression levels of inflammatory genes. Allografts from Par2-deficient mice showed less histological damage and less graft infiltrating CD8 cells as compared to their wildtype controls.

Conclusion:
These data show that CatS/Par2 is critically involved in the pathogenesis of allograft rejection

Uniklinik München
Background: Liver transplant (LT) is the only available cure for end stage liver disease (ESLD). In adults, total hepatectomy with portocaval shunt and subsequent LT as a two-stage procedure following a prolonged anhepatic phase is an accepted approach in the presence of toxic liver syndrome. Although the procedure is well described in adults, literature in children is absent.

Materials and methods:
Clinical case report

Results:
We here describe a case of a 2-year old boy who, while awaiting liver transplantation for ESLD from biliary atresia and failed Kasai, developed toxic liver syndrome with subsequent multiorgan failure and cardiopulmonary instability. Too sick to transplant, he underwent full hepatectomy with portocaval shunt placement and was taken back to the ICU, were he dramatically stabilized in the subsequent hours. In the mean time, a liver of poor quality had been accepted from a 58 yo old obese female as a bridging organ, and this organ was split ex situ for a left lateral segment. The child was successfully transplanted after an anhepatic phase of 12 hours. As expected, the graft showed only decent synthetic function and poor biliary clearance, however, the child stabilized further to come entirely of pressors and to recover all organ functions. After 14 days, the child underwent a second transplant, which was a left lateral segment from a 26-old male donor from an ex vivo split. Despite excellent graft function, naturally, the child had a challenging postoperative course. He was discharged home in good conditions at 4 months and was well with a fully working graft nine months following transplantation.

Conclusion:
In dire situations of toxic liver syndrome with multiorgan failure, total hepatectomy with portocaval shunt placement and LT as a two-stage procedure is a feasible option not only in adults, but also in children.

Background:
The Model for End-stage liver disease (MELD) based allocation system has been implemented in Germany in 2006 in order to reduce waiting list mortality. Purpose of this study is to evaluate posttransplant outcome and waiting list mortality -especially under the aspect of increasing organ shortage in Germany.

Materials and methods:
All patients undergoing liver transplantation (LT) in Germany from 2004 to 2015 were assessed retrospectively using the electronic record system of Eurotransplant (ET). The study period was divided into three time sections (A: Pre-MELD 2004-2006B: post-MELD low donor 2007B: post-MELD low donor -2010C: post-MELD high donor 2011C: post-MELD high donor -2012. During this period 21444 patients were registered patients on the waiting list for liver transplantation in Germany.

Results:
From 2004 to 2015 a total of 12762 LTs were performed in Germany. After MELD implementation, the median matchMELD at time of LT increased from 17 to 28 in 2015. Donation rate increased after 2004 and remained stable from 2006 to 2011 (around 14 per million inhabitants), but decreased afterwards considerably to 10.4 organ donors/million in 2015. Compensatory, during this period, median donor age increased from 44 to 53 years (p<0.001) and the percentage extended donors (age>=65years) increased from 11.1% to 25.4%. The ratio of used liver donors to reported donors was found to be notably higher in Germany (around 85% since MELD implementation) compared to other ET countries (around 77%). Comparing the different time periods 3-year patient survival in group A was 72.2%, 67.4% group B in group B and then remained constant at 69.1% in group C 2011-2012 (A vs. B, p<0.001; B vs. C, p=0.282). When analyzing patients who died on waiting list or were removed due to poor health status (=mortality), the absolute number was constant over the years (median 388; IQR 334-470; p=0.63). However, the quotient of mortality and actively listed patients increased noticeably from 0.16 to 0.26 (p=0.0045).

Conclusion:
Organ shortage lead to looser acceptance of marginal organs since MELD implementation. Despite an initial increase of organ donors survival declined after MELD implementation in Germany with no benefit for waiting list mortality.

Background:
Pleural effusion is the most common complication in the immediate postoperative course after liver transplantation and frequently chest drain placement is required. Aim of our study was to investigate the incidence of drainage requiring pleural effusions after liver transplantation and to analyze intervention-related complications.

Materials and methods:
This is a retrospective observational study from a high volume liver transplant center in Germany. Adult liver transplant recipients between 2009 and 2016 were analyzed for pleural effusion formation, its therapy and consecutive complications after liver transplantation. Primary outcome was defined as the need for placement of chest drain within the first 10 post-operative days. Furthermore, complications associated with chest drain, occurrence of pneumonia and need for blood products prior to intervention were analyzed.

Results:
Overall, 597 patients were included, of which 361 (60.5%) had at least one chest drain within the first 10 post-operative days. Patients with a MELD >25 were more frequently affected (75.7% vs. 56.0%, p<0.001). Typically, chest drains were placed at the intensive care unit (ICU) (68.3%) or in the operating room (14% during transplantation, 11% in the context of reoperations). In total, 97.0% of the patients received a right-sided chest drain, presumably caused by local irritations. Due to poor liver function, one third of patients staying in the ICU needed pre-interventional optimization of coagulation. Out of 361 patients receiving a chest drain 14 (3.7%) suffered from post-interventional hemorrhage and 6 (1.4%) from pneumothorax requiring further medical treatment. Comparing the setting of the placement, less complications were observed when performed in the operating room during transplantation or reoperation as compared to the placement at ICU (1/116 (0.9%) vs. 20/316 (6.3%); p=0.019).

Conclusion:
Pleural effusion is the most common complication after liver transplantation requiring intervention in the majority of the cases, especially in high-MELD patients. Routinely placed chest drain during liver transplantation may reduce complications, avoid unnecessary coagulation products and may prevent pneumonia. Hand-assisted laparoscopic living donor nephrectomy (HALDN) using a periumbilical or Pfannenstiel incision was developed to improve donor outcome after a kidney transplant. The aim of this study was to investigate two methods of hand assistance and kidney removal during HALDN and their effect on the time it takes for the donor to return to normal physical activity.

Materials and methods:
This study was initiated in November 2017 and is expected to last for 2 years. To be eligible for the study, donors must be more than 20 years of age and must not be receiving permanent pain therapy. Only donors with a single artery and vein in the graft are being enrolled in this trial. Donors with infections or scars in the periumbilical or hypogastric area, bleeding disorders, chronic use of immunosuppressive agents, or active infection will be excluded. Donors will be randomly allocated to either a control arm (periumbilical incision) or an intervention arm (Pfannenstiel incision). The sample size was calculated as 26 organ donors in each group. The primary endpoint is the number of days it takes the donor to return to normal physical activity (up to 4 weeks after the operation). Secondary endpoints are intraoperative outcomes, including estimated blood loss, warm ischemia time, and duration of the operation. Postoperative pain will be assessed using the visual analog scale, rescue analgesic use, and peak expiratory flow rate. Length of hospital stay, physical activity score, time to return to work, donor satisfaction, cosmetic score, postoperative complications, and all-cause mortality in living donors will also be reported. Delayed graft function, primary non-function, serum creatinine levels, and glomerular filtration rate will also be assessed in the recipients after transplantation. The trial was registered at ClinicalTrials.gov under registration number NCT03317184 on 23 October 2017.

Conclusion:
This is the first randomized controlled trial to compare the time it takes the living donor to return to normal physical activity after HALDN using two different types of incision. The comprehensive findings of this study will help decide which nephrectomy procedure is best for living donors with regard to patient comfort and satisfaction as well as graft function in the recipient after transplantation.

Background:
Despite advances in surgical methods, incidence of wound complications after kidney transplantation (KTx) is still considerable. In this study we investigated the impact of prophylactic mesh reinforcement on the incidence of wound complications and short-term fascial dehiscence in KTx patients.

Materials and methods:
Forty-six patients were included in the no-mesh group and 23 patients received onlay mesh reinforcement. Multivariate analysis was performed to determine predictors of SSI, wound/fascial dehiscence after KTx.

Conclusion:
Mesh reinforcement decreased the risk of overall wound complications and short-term fascial dehiscence without increasing the risk of SSI in KTx patients. These findings alongside with long-term results have to be evaluated in a randomized trial setting. Diverticulitis of the sigmoid colon counts to the commonest abdominal disorders in the western world. Allocation for a certain strategy is stage based or individualized, according to the respective national guideline. A meaningful, but so far insufficiently recognized aspect for an individualized therapeutical decision making is patients health related quality of life (QoL). The presented study intends to analyze QoL in patients with conservative respectively surgical treatment for complicated and uncomplicated diverticulitis in the long-term.

Materials and methods:
Consecutive patients, hospitalized between October 2009 to November 2015 for primarily conservative treatment of uncomplicated and complicated diverticulitis of the left colon were included into the analysis. Therein, patients with and without elective surgical treatment were identified. Disease severity was staged in accordance to the Classification of Diverticular Disease (CDD) and modified Hinchey classification. Patients with perforated disease and generalized peritonitis were excluded. A retrospective chart review of all included patients was conducted. Moreover, patients were asked by telephone to answer a standardized interview and the Short form 36 questionnaire for assessing current quality of life.

Results:
Between October 2009 and November 2015, 392 patients (184 M:208 F, mean age: 60,5 (27-91) underwent overall 429 hospitalizations for primarily conservative treatment of acute diverticulitis. 279 patients (M: 138, F: 141; Age mean 60,5 years, Range 27-91 years) filled out questionnaires regarding quality of life after a median follow-up period of 37.8 months (range 15-85 Months). 62 patients underwent sigmoid resection during the initial treatment. Overall, 99 patients had undergo surgery for diverticular disease between the initial hospital stay and the time of filling out the questionnaire. Distribution of patients according to the CDD Classification is shown in Table 1. In uncomplicated disease, no differences in quality of life were found for non operated and operated patients. In complicated disease with sealed perforation -/+ microabscess (CDD stage 2a) SF36 subscales "social functioning" and "role emotional" were significantly superior in the non operated group. The same was shown in complicated disease with pericolic macroabscess (CDD stage 2b). Therein, non operated patients had significant higher results in the subscales "social functioning", "role emotional" and moreover in the subscale "vitality". Other subscales were without differences for both, CDD stage 2a and 2b.

Conclusion:
Elective surgery has no significant positive influence on long-term quality of life in patients with uncomplicated and complicated diverticulitis if perforated disease is excluded. Conservative treatment seems to have partly positive influence on quality of life in patients with compicated disease (CDD 2a and 2b). The number of patients with pericolic abscesses, who underwent non-surgical strategy was to low for the assessment of reliable results. However, indication for elective surgery must be made carefully and restrictive in uncomplicated disease and in case of microabscess due to the limited positive impact on patients wellbeing.

Background:
Surgical Procedure Manager (SPM) is a software tool for standardization, work flow optimization and surgical training using a precast precept defining particular steps of surgical procedures mostly eligible for procedures with a low variability of sequence and execution of certain steps and used instruments. It includes a list and visualization of required instruments, intended surgical steps as well as a time module starting with the positioning of a patient on the table. SPM thereby is considered not only to decrease time needed for the procedure itself but also transfer times and anesthesia.

Materials and methods:
SPM (Surgical Process Institute Deutschland GmbH, Leipzig) was implemented for several surgical procedures, currently including laparoscopic cholecystetomy, PPPD, and kidney transplantation. Experienced surgeons defined certain steps of each procedure and the desired time and instruments needed for each step. Both, experienced surgeons as well as trainees performed the procedures using SPM: each predefined step is announced by the system vocally to optimize the work flow of surgeons in training and assisting personnel. The information serves the OR administrators and anesthesiologist for planning following cases in this particular OR. Recording begins with positioning the patient on the table and establishing sterile conditions. Each finished step during surgery is then testified by the leading surgeon via pressing a foot pedal. Continuous comparison of actual and desired time frames for certain steps allows constant feedback and an accurate forecast of the expected end of the procedure.

Results:
The SPM can easily be used by every surgeon performing one of the standardized procedures. It has been used for 33 procedures in the time between April and August 2018 with an evaluable amount of 45%. SPM was started and not sufficiently finished in the other 55%. The using rate increased after a first feedback round in May to a peak level of 33% for the average of all included procedures in July. The laparoscopic cholecystectomy and the PPPD reached a using rate of 50% each. Due to simultaneously performed procedures the ultimate using rate for July was calculated with 75% using only one tower. Particularly surgeons in training and the assisting personnel as well as students and nurses subjectively report about advantages in the usage of SPM especially for determination of procedure key and endpoints and thereby the workflow during the certain procedure as well as coordinating anesthesia and procedures to follow.

Conclusion:
SPM is easy to use and our first experiences are promising: transparency of real-time information serves work flow optimization. Both, the team within the OR as well as external coordinators were able to improve process parameters within an OR of a large University hospital. Nevertheless, SPM usage is subject to a learning curve. Furthermore, only procedures with a low variability of sequence, techniques and necessary instruments, such as the laparoscopic cholecystectomy, appeared to be feasible. Hospitals treating colorectal tumors can obtain a certification by the DKG if they meet high qualitystandards. It is yet unclear if surgery at such Colorectal Cancer Centers leads to a survival benefit.

Materials and methods:
Data for this retrospective cohort study derives from an official German cancer-registry, which collects medical and demographical information of all tumor patients registered within a political district of 1.1 million inhabitants. To compare 3-year-survival rates of center-and non-center-cases 2312 patients who had their colorectal adenocarcinoma removed between 2010 and 2013 were included in Kaplan-Meier-and multivariate Cox-regression-analysis. Additionally, center cases were checked against 1690 cases before 2008 from the same hospitals using relative survival methods to control for temporal changes in life expectancy.

Conclusion:
Treatment at Colorectal Cancer Centers is associated with superior survival. However, the receipt of a certification did not alter patients' survival rates visibly, presumably because the later centers began to implement the DKG's high standards even before 2004.