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  • Author: Andreas Hoyer x
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Abstract

Internet-Technologien und neue Medien verändern die Ausbildung und den Erwerb von Information auch im Hochschul-Bereich nachhaltig. Speziell im Bereich der Automatisierungs- und Regelungstechnik sind hochwertige Animationen und Simulationen im Netz verfügbar, die durch Interaktion das Verständnis von Sachverhalten erleichtern. Die praktische Umsetzung von Lerninhalten wird durch Teleoperation von realen Systemen in "virtuellen Laborexperimenten" über das Internet ermöglicht. Der Beitrag beschreibt einen Ansatz zur Teleoperation eines Brückenkranes und eines inversen Pendels und die dazu benötigte Infrastruktur und Systemarchitektur. Zudem wird hier ein Mehrbenutzer-Szenario vorgestellt, welches die zeitgleiche Kollaboration mehrerer Praktikumsteilnehmer erlaubt.

Abstract

Aim of the study

Living donor liver transplantation (LDLT) is regularly performed in small-sized infants. Computed tomography (CT)-based donor liver volumetry is used to estimate the graft size. The aim of our study was to assess the results of CT liver volumetry and their impact on the clinical outcome after LDLT in extremely small-sized infants.

Patients and methods

In this study, we included all patients with a body weight of ≤10 kg who underwent living related liver transplantation at our centre between January 2004 and December 2014. In all cases of LDLT, a preoperative CT scan of the donor liver was performed, and the total liver and graft volumes were calculated. The graft shape was estimated by measuring the ventro-dorsal (thickness), cranio-caudal, and transversal (width) diameter of segment II/III. We assessed the impact of CT donor liver volumetry and other risk factors on the outcome, defined as patient and graft survival.

Results

In the study period, a total of 48 living related liver transplantations were performed at our centre in infants ≤10 kg [20 male (42%), 28 female (58%)]. The mean weight was 7.3 kg (range 4.4–10 kg). Among the recipients, 33 (69%) received primary abdominal closure and 15 (31%) had temporary abdominal closure. The patient and graft survival rates were 85% and 81%, respectively. In CT volumetry, the mean estimated graft volume was 255 mL (range 140–485 mL) and the actual measured mean graft weight was 307 g (range 127–463 g). The mean ventro-dorsal diameter of segment II/III was 6.9 cm (range 4.3–11.2 cm), the mean cranio-caudal diameter was 9 cm (range 5–14 cm), and the mean width was 10.5 cm (range 6–14.7 cm). The mean graft-body weight ratio (GBWR) was 4.38% (range 1.41–8.04%). A high graft weight, a GBWR >4%, and a large ventro-dorsal diameter of segment II/III were risk factors for poorer patient survival.

Conclusion

Preoperative assessment of the graft size is a crucial investigation before LDLT. For extremely small-sized recipients, not only the graft weight but also the graft shape seems to affect the outcome.