A new method of veno-venous bypass during human orthotopic liver transplantation

Veno-venous bypass is commonly used during orthotopic liver transplantation, but there is some controversy as to whether it contributes to a better outcome. Low shunt flows frequently reduce the efficacy of portofemoro-axillary systems and so a percutaneous cannulation technique for the subclavian and femoral vein with large bore catheters was developed in order to facilitate bypass management. This study reports the performance and complications of a portofemoro-subclavian bypass system during the anhepatic phase of human orthotopic liver transplantation in 85 patients. A percutaneous cannulation technique and two 7 mm (subclavian and femoral) catheters, inserted pre-operatively, were used in a pump driven portofemoro-subclavian bypass system. Coagulation profiles, shunt flows, haemodynamic parameters, and peri-operative complications associated with bypass were recorded for each patient. Percutaneous cannulation of the left femoral and subclavian vein was successful in 78 patients (91.8%). Mean femoro-subclavian shunt flow was 1.45 l.min-1 (SD 0.37), and mean portofemoro-subclavian flow was 4.28 l.min-1 (SD 1.03). Although oxygen delivery was not maintained at pre-shunt levels (559.7 (SD 147) vs 506 (SD 107) ml.min-1.m-2, p < 0.05) renal perfusion pressure stayed above 50 mmHg (during shunt it was 56 (SD 9) mmHg). One intra-operative air embolism was observed (1.2%), and in one patient a myocardial infarction occurred during the anhepatic phase; neither complication was considered to be related to the percutaneous cannulation technique. There were no bleeding complications. After operation, all chest X rays were normal and clinical examination revealed no adverse effects of portofemoro-subclavian bypass.(ABSTRACT TRUNCATED AT 250 WORDS)