Byers W. Shaw

Two general kinds of liver transplantation have been attempted clinically. With one approach, the host liver is removed and replaced with a homograft (orthotopic liver transplantation); alternatively, an extra liver is inserted at an ectopic site (auxiliary homotransplantation). This review concerns only orthotopic liver transplantation.

The blood coagulation system of 66 consecutive patients undergoing consecutive liver transplantations was monitored by thrombelastograph and analytic coagulation profile. A poor preoperative coagulation state, decrease in levels of coagulation factors, progressive fibrinolysis, and whole blood clot lysis were observed during the preanhepatic and anhepatic stages of surgery. A further general decrease in coagulation factors and platelets, activation of fibrinolysis, and abrupt decrease in levels of factors V and VIII occurred before and with reperfusion of the homograft. Recovery of blood coagulability began 30-60 min after reperfusion of the graft liver, and coagulability had returned toward baseline values 2 hr after reperfusion. A positive correlation was shown between the variables of thrombelastography and those of the coagulation profile. Thrombelastography was shown to be a reliable and rapid monitoring system. Its use was associated with a 33% reduction of blood and fluid infusion volume, whereas blood coagulability was maintained without an increase in the number of blood product donors.

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 (LT). 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 LT without bypass (NBP), the 57 total BP patients experienced better postoperative renal function (p less than 0.001), required less blood use during surgery (p less than 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 LT as a service-oriented procedure.

Fifty-four patients underwent total hepatectomy and liver replacement in the presence of a primary liver malignancy. In 13 recipients in whom the hepatic tumors were incidental to some other endstage liver disease, recurrence was not seen and 12 of the 13 patients are alive after 4 months to 15 1/2 years. In contrast, tumors recurred in 3 of every 4 patients who received liver replacement primarily because of hepatic malignancies that could not be resected by conventional techniques of subtotal hepatectomy and who lived for at least 2 months after transplantation. The most encouraging results were in patients with the fibrolamellar hepatocellular carcinomas that grow slowly and metastasize late, but even with this lesion, the recurrence rate was 57%. In future trials, additional effective anticancer therapy will be needed to improve the results of liver transplantation for primary liver malignancy, but what an improved strategy should be has not yet been defined.