Abstracts DGT

The number of inductive immunochemotherapy (IO+CTx) in patients with lung cancer and higher-grade tumor stages is increasing. Actually the impact of IO+CTx on extended lung resections is unclear. The goal of this study was to analyze the short-term outcomes after extended lung cancer resections.


Background:
The number of inductive immunochemotherapy (IO+CTx) in patients with lung cancer and highergrade tumor stages is increasing.Actually the impact of IO+CTx on extended lung resections is unclear.The goal of this study was to analyze the short-term outcomes after extended lung cancer resections.

Materials and methods:
We retrospectively analyzed our patients with extended lung cancer resections after IO+CTx between 2020-2023.In total, 17 patients were included.Descriptive statistical analysis included the characteristics of the patients, tumors, and short-term outcomes.

Results:
In total, 8 female and 9 male patients with a median age of 62 years (range 52-71 years) could be included in the study.16 patients with non-small cell lung carcinoma and one patient with small cell lung carcinoma were included in the study.Majority of the patients (n = 13) received immunochemotherapy with Pembrolizumab.In total, 7 sleeve resections (1 sleeve resection, 1 sleeve resection with combined chestwall resection, 1 bilobectomy with y-sleeve-resection, 1 double-sleevelobectomy and 1 double-sleeve-lobectomy with bilobectomy with combined chest wall resection, 2 ysleeve-resections), 4 lobectomies with chestwall resection, 1 bilobectomy, and 1 bilobectomy with chestwall-resection were performed.R0 resection rate was 100%.Postoperative morbidity rate was 52.9 % (n = 9).The most common observed postoperative complication was cardiac arrhythmia in 5 patients.Two patients needed revision surgery.Observed 30-day mortality was 0%.The rates of complete and major pathologic response were 35.3 % ( n = 6) and 17.6% (n = 3), respectively.

Conclusion:
Although the number of included patients is small, the study shows that extended resections after immunochemotherapy are feasible with a good outcome.In total, a high rate of R0 resection is achievable.

Background:
The application of ECMO in general thoracic surgery has become more common during recent years.While there are several reports on mainly minor surgical procedures and perioperative indications of ECMO, there is a scarcity of information regarding indications and outcome of major anatomical lung resections under ECMO support.

Materials and methods:
At a German university hospital all patients, who underwent pulmonary lobectomy or pneumonectomy under ECMO support, were identified from a prospectively collected database.Indications, ECMO setting and overall results were analyzed.Study period was 01/2018 to 06/2023.All procedures were performed by the same team of thoracic surgeons.

Conclusion:
ECMO is an excellent tool to overcome marginal functional operability in elective patients with technical resectable lung cancer and to overcome temporal functional inoperability in emergency patients with conditions requiring pulmonary lobectomy or pneumonectomy.In the elective setting not only the actual ECMO cases but many more with very borderline functional operability, who would otherwise not be considered for surgery, benefit from the readiness to use ECMO and get the chance to receive operative treatment with curative intent.

Materials and methods:
A 71-year-old male patient presented in good general condition for further diagnosis of right pleural thickening without pleural effusion.In the absence of clinical symptoms and in good cardiopulmonary condition, the finding had come to attention during an externally performed diagnostic procedure using CT of the thorax to exclude pulmonary artery embolism after thrombophlebitis of the great saphenous vein on the right side.There was no known exposure to asbestos.Diagnostic video-assisted thoracoscopy revealed spherical, reddish-livid deposits on the parietal pleura and diaphragm.The visceral pleura showed no abnormalities.Representative biopsies were sent for histopathologic examination.

Results:
Complex histologic workup revealed the presence of pleural mesothelioma of lymphohistiocytoid subtype.Differentially, Hodgkin's lymphoma, thymic neoplasia and lymphoepithelial tumors must be considered.Characteristic were strong CK18, AE1/3, WT1, D2-40, GATA3, EMA and calretinin expressions and a conspicuous presence of the lymphoid component of the cytotoxic T cells.BAP1 showed preserved nuclear expression.CD68 and CK5/6 were found to be negative.There was no evidence of Epstein-Barr virus-related infection.Furthermore, PD-L1 expression was 80%, so immunotherapy was initiated.

Conclusion:
The lymphohistiocytoid variant of malignant mesothelioma is rare with only very few cases described in the literature so far.It is characterized by mesothelial cells with a histiocytelike appearance and an associated dense lymphoid infiltrate.Nevertheless, detailed immunohistochemical workup is necessary to allow accurate differentiation of subtypes for final diagnosis and thus further clinical treatment and therapeutic options.

Background:
The primary synovial sarcoma of the mediastinum is a rare tumor with an low incidence of 11% and lack of unified treatment.According to histology a monophasic, biphasic and poorly differentiated types can been distinguished.Due to the slow growing pattern most of tumors remain asymptomatic for a long time and were detected in unresectable stage combined with a compression of neighboring structures.Particularly the vena cava superior syndrome is associated with a poor prognosis.So far only four cases with monophasic mediastinal sarcoma with vena cava superior syndrome were reported, while only one patient received a complete resection after neoadjuvant chemotherapy.Three other patients demonstrated an unresectable sarcoma.

Materials and methods:
In a 15 year old boy has been presented in our university hospital with dyspnoea, persistent dry cough, pain in the right shoulder and constant subfebrile temperatures.Based on radiological diagnostics a giant, well-circumscribed, inhomogen tumor in the right anterior mediastinum associated with a compression of vena cava superior and complete atelectasis of the right lung were detected (Fig. 1).After a CT-guided biopsy histological analysis reveal a monophasic synovial sarcoma.

Results:
After 3 cycles of neoadjuvant-intended chemotherapy with ifosfamid/vincristin/actinomycin-D the tumor persists without any signs of radiologic response.Moreover a spontaneous intratumoral bleeding causing a blood transfusion and increase of inflammatory parameters in the blood analysis.Based on persisted tumor associated with vena cava superior syndrome the respectability was difficult to predict from surgical point of view.Therefore chemotherapy regime was changed to cisplatin/etoposide.According to the interdisciplinary board after completion of chemotherapy a salvage surgery was considered as the best possible treatment option in order to achieve the complete tumor resection.An extended tumor resection combined with a partial resection of pericardium, replacement of vena cava superior due to Dacron prothesis, decortication of the right lung and extended pleurectomy was performed via clamshell incision (Fig. 2, 3).The postoperative histological analysis confirmed a complete tumor resection (R0) with 95% of tumor cell necrosis demonstrating a near to complete histological response (Fig. 4, 5).Caused due to postoperative intrapleural hematoma after an extended pleurectomy and decortication of the right lung was performed 3 days later.Other hospital stay was uneventful and the patient could be dismissed on 13 day (Fig. 6).Based on goof histological response and high risk of locoregional recurrence a adjuvant chemotherapy with four cycles of ifosfamid/vincristin/actinomycin-D was performed.At 6 month follow up the patient reported a good recovery with near to regular level of physical strain.During radiological staging analysis no metastasis and no local recurrence were evident.

Conclusion:
Complete surgical resection is only known factor associated with long-term survival in patients with synovial sarcoma and remains a important part of aggressive multidisciplinary therapy.The extended surgery particularly in cases with vena cava superior syndrome should be expected in order to achieve the prognostically important complete resection.  Universitätsmedizin der Johannes Gutenberg-Universität Mainz, Zentrum für Thoraxerkrankungen, Mainz, Deutschland

Background:
A 60-year old female patient was referred for further diagnosis and treatment of a posterior mediastinal lesion.The lesion was incidentally discovered in a CT scan of the chest and abdomen, which had been performed due to an increased CA 19-9 in routine blood tests.At the time point of the referral the lesion had already been biopsied twice (CT guided and through EUS) but the histopathology was inconclusive.

Materials and methods:
Upon referral we repeated the CT guided biopsy and the transesophageal ultrasound.The second did not reveal any invasion of the esophagus.Both biopsies were inconclusive again.We discussed with the patient a thoracoscopic exploration in order to evaluate the extent of the disease, the exact location and its relationship to the adjacent structures.

Results:
The procedure was performed through a bilateral uniportal VATS approach.The lesion was originating from the right lower lobe.The lesion was mobilized from all the adjacent structures on both sides, the feeding vessel from the descending aorta was ligated and the lesion was extracted en-bloc through the left uniportal incision.

Conclusion:
The histopathological report revealed an extralobar pulmonary sequestration.Six weeks after surgery the CA 19-9 values had returned to normal.The transmediastinal, bilateral manifestation of the sequestration, the age of the patient and the unusual increase in the tumor markers make this altogether a very rare example of an extrapulmonary sequestration.
Oligometastatic lung carcinoma or synchronous bilateral double primary lung carcinoma?ID: 867 Andreas Kilian 1 , Stefan Sponholz 1 , Mesut Mese 1 , Stephan Trainer 1 1 Klinik für Thoraxchirurgie,Agaplesion Markus Krankenhaus Frankfurt,4,Frankfurt am Main,Deutschland Background: Differentiating between a bilateral double carcinoma and an oligometastic lung carcinoma before initiating therapy is essential to define the correct treatment strategy in an interdisciplinary tumour conference.We present the case of a 62-year-old female patient with bilateral double carcinoma that was erroneously diagnosed primarily as synchronous oligometastatic lung carcinoma.

Materials and methods:
The patient was externally diagnosed with lung carcinoma originating from the right lower lobe of the lung with a metastasis to the left lower lung lobe and a N2 situation detected by TBNA.Immunochemotherapy with pemetrexed/carboplatin/pembrolizumab was given for a supposed stage IV A, followed by maintenance therapy with pembrolizumab.PET computed tomography showed discordant response with increased hypermetabolism and size progression on the right side and tumor regression on the left side.The patient was presented to our clinic.In case of discordant response, the interdisciplinary tumor conference recommended a bilateral resection.Initially, the right side was resected through an extended lower lobe resection with systematic lymph node dissection.Already here, a deviating pathology in the lower lobe preparation compared to the mediastinal lymph nodes became apparent, so that the suspicion of a bilateral double carcinoma was substantiated.A Y-sleeve resection of the lower lobe with systematic dissection of the lymph nodes was performed on the left side.

Results:
The presence of a synchronous double carcinoma with respective mediastinal N2-situation was confirmed.On the right side, there was an adenocarcinoma with mucinous differentiation and singlelevel N2 situation, ypT2b, ypN2 (2/43), R0, stage III A. On the left side, there was adenocarcinoma with solid, acinar and lepidic growth pattern and single-level N2 situation, ypT1c, ypN2 (5/48), R0, stage III A. Initial histopathological workup of TBNA examination from lymph node position 4 on the right showed a questionable EGFR mutation.This could not be confirmed in the postoperative workup of both surgical specimens.A formal indication for adjuvant radiotherapy due to the present N2situation was not recommended, because there was no capsular overgrowth and due to the patient's constitution.Overall, no adjuvant therapy was performed.Since then, the patient has undergone regular follow-up with computed tomography of the thorax every six month and annual bronchoscopic sleeve checks.After 27 months of follow-up, she is still free of recurrence.

Conclusion:
A regular interdisciplinary exchange and critical re-evaluation of individual treatment steps and outcomes are essential in the management of complex cases.In the case of bilateral lung tumors, histologic confirmation of both sides of the tumor may be indicated to avoid premature misclassification and subsequent incorrect therapy regimen.

Fig. 1 .
Fig. 1.Initial MRI demonstrating a massive tumor mass with compression of vena cava superior.

Fig. 4 Fig. 6 .
Fig.4 and 5.The histopathology confirmed a complete resection of synovial sarcoma demonstrating a near to complete pathologic response with a 95% tumor necrosis following the preoperative chemotherapy.