Venous Bypass in Clinical Liver Transplantation

Abstract

A venous bypass technique (BP) that does not require the use of systemic anticoagulation is used routinely at our institution in all adult patients during the anhepatic phase of liver transplantation (L T). Complete cardiopulmonary profiles were obtained in a subset of 28 consecutive cases. During the anhepatic phase while on bypass, mean arterial pressure, central venous pressure, and pulmonary arterial wedge pressure were maintained at prehepatectomy levels. Oxygen consumption fell secondary to a decrease in temperature and the removal of the liver. Consequently, cardiac index fell without an increase in arterial-venous O2 content difference, reflecting adequate tissue oxygenation. Compared with 63 patients in a previous series given L T without bypass (NBP), the 57 total BP patients experienced better postoperative renal function (p < 0.001), required less blood use during surgery (p < 0.01), and had better survival 30 days after LT. The equivalency of 90-day survival in these groups results from the lack of effect of BP on the long-term survival of patients considered at high risk for metabolic reasons. BP patients at high risk for technical considerations, however, survived LT whereas NBP patients did not. BP offers other advantages important in establishing L T as a service-oriented procedure.T HE DRAMA TIC IMPACT of cyclosporine on survival following liver transplantation has been widely reported. I -4 Yet despite extensive experience with the operation during the preceding 17 years, only a few important technical improvements were reported to have significantly enhanced survival. 3 • 5 -s In fact, during the first 3 years in which cyclosporine was used, mortality related to a difficult intraoperative course remained a disturbing problem. For the most part, these difficulties centered around the anhepatic phase and repeatedly underscored the need for an effective method of venous bypass. The need for the development of new methodology was clearly demonstrated by the severe penalty imposed by the requirement for systemic heparinization during a trial of venous bypass using conventional

Right lobe living donor liver transplantation with or without venovenous bypass

“…It allows time for the surgeon to perform faultless venous anastomoses, and was considered to play a major role in the improvement of results of liver transplantation in the 1980s and dissemination of the transplant technique to the new generation of surgeons 1,2 . However, apart from the cost of the equipment and personnel required to monitor the procedure, complications such as air embolism 3 , massive bleeding, activation of complement factors, fibrinolysis 4 , haemolysis 5 , entrapment of platelets in the tubing 6 , hypothermia 7 , injury to brachial plexus and artery 8 , and lymphatic leakage 9 contribute to patients' morbidity and mortality 10 .…”

Orthotopic Liver Transplantation with Preservation of the Inferior Vena Cava

“…The safety and ease of the operation have been improved by the use of a veno-venous bypass technique that permits the obstructed vena cava as well as the occluded splanchnic venous system to be decompressed during the anhepatic phase. 3 We report here a piggyback modification of this procedure whereby the full length of the recipient inferior vena cava is preserved. This kind of operation has been performed before,I-4 but it has not been fully described.…”

Air embolism as a complication of venovenous bypass during liver transplant for diffuse hemangiomatosis

“…1 In spite of this equipment, our case shows that air detectors may fail to detect small entries of air-so insignificant that visual inspection is unable to see them-but great enough to accumulate in the lungs and produce right heart failure and circulatory collapse. This complication seems to be rare, 2 but its potential danger demands that during bypass; independent of the detection of air in the system, attention must always be paid to early signs of gas embolism, namely a decreased expired carbon dioxide associated with an increased pulmonary artery pressures.…”