Timing of arterialization in liver transplantation

This study analyzed the pathophysiologic sequela of different modes of graft reperfusion in liver transplantation.

The grafted liver may be reperfused either immediately after completion of portal anastomosis followed by delayed arterial reconstruction or simultaneously by portal and arterial blood if all vascular anastomoses are completed during the anhepatic period.

Delayed arterialization, that is, arterial reperfusion 8 minutes after portal revascularization (n = 12), was compared with simultaneous arterialization (n = 8) using the model of syngeneic orthotopic liver transplantation in male Lewis rats. After cold storage for 24 hours in University of Wisconsin (UW) solution, intravital fluorescence microscopy was employed 30 to 90 minutes after reperfusion to assess hepatic microvascular perfusion, leukocyte accumulation, and phagocytic activity of Kupffer cells.

Compared with delayed arterialization, the number of both nonperfused acini and nonperfused sinusoids was reduced after simultaneous reperfusion by 71% (p = 0.008) and 78% (p < 0.001), respectively. Leukocyte accumulation in sinusoids and postsinusoidal venules after simultaneous arterialization decreased by 17% (p = 0.01) and 64% (P < 0.001), respectively. In addition, simultaneous revascularization was able to attenuate Kupffer cell activation, indicated by significantly slower adherence of latex beads injected 80 minutes after reperfusion. Improved hepatocellular excretory function after simultaneous arterialization was demonstrated by increased bile flow during the observation period of 90 minutes after reperfusion (2.24 +/- 0.7 vs. 0.95 +/- 0.4 mL/100 g liver [mean +/- SEM], p < 0.05).

Timing of arterial reperfusion in liver transplantation may be of critical importance in the prevention of various manifestations of reperfusion injury.