Changes in portal vein flow after adult living-donor liver transplantation: does it influence postoperative liver function?

In adult living donor liver transplantation, using small grafts in cirrhotic patients with severe portal hypertension may have unpredictable consequences. The so-called small-for-size syndrome is present in most series worldwide. The goal of this study was to prospectively evaluate the influence of hemodynamic changes on postoperative liver function and on the percentage of liver volume increase, in the setting of living donor liver transplantation. Twenty-two consecutive adult living donor liver transplantations were performed at our institution in a 2-year period. We measured right portal flow and right hepatic arterial flow with an ultrasonic flow meter in the donor, and then in the recipient 1 hour after reperfusion. Postoperative liver function was measured by daily laboratory work. We also performed duplex ultrasounds on postoperative days 1, 2, and 7. Liver volume increase was estimated by magnetic resonance imaging graft volumetry at 2 months posttransplantation. We compared the blood flow results with the immediate liver function and its liver volume increase rate at 2 months. There was a significant increase in portal flow in the recipients compared with the donors (up to fourfold in some cases). Higher portal flow increase rates significantly correlated with faster prothrombin time normalization and faster liver volume increases. Median graft volume increase at 2 months was 44.9%. The increase in blood flow to the graft is well tolerated by the liver mass not affecting hepatocellular function as long as the graft-to body weight ratio is maintained (>0.8) and adequate outflow is provided.