Effect of repeated portal-triad cross-clamping during partial hepatectomy on hepatic regeneration in normal and cirrhotic rats.

The effects of ischemia/reperfusion during 70% partial hepatectomy on hepatic regeneration was evaluated in normal rats and thioacetamide-induced cirrhotic rats. Total hepatic ischemia and reperfusion (15 min each) by portal-triad cross-clamping was repeated two times in normal rats and four times in cirrhotic rats during hepatectomy. The labeling index of hepatocytes on Day 1 after operation (POD) and hepatic regeneration ratio on POD 28 were measured. In normal rats, the repeated ischemia/reperfusion decreased the survival rate from 100 to 77% (P < 0.05), lowered the hepatocyte labeling index from 33.5 +/- 2.5 to 16.7 +/- 6.5%, and diminished the hepatic regeneration ratio from 199 +/- 17 to 137 +/- 12% (P < 0.01). However, portal-systemic shunt improved those levels to 100, 30.6 +/- 13.7, and 169 +/- 19%, respectively (P < 0.01). In cirrhotic rats, no portal congestion was observed and hepatic regeneration was not suppressed by ischemia/reperfusion. Thus, portal pooling and the reperfusion of pooled portal blood may be the cause of inhibition on hepatic regeneration and not ischemia/reperfusion of the liver itself. Therefore, repeated portal-triad cross-clamping for short periods of time during the resection of cirrhotic liver is not harmful for hepatic regeneration.