An experimental study of survival after two hours of normothermic hepatic ischemia.

Total hepatic inflow occlusion is well tolerated in pigs with normothermia for as long as two hours, provided that splanchnic venous pooling is avoided by active pumping through a splenojugular bypass. Hepatic dysfunction after 60, 90 and, even, 120 minutes of hepatic ischemia is mild and transient. Complete return to normal liver function tests is rapid. Early microscopic alterations of the liver are moderate, and no late abnormalities, such as cirrhosis or vascular changes, were observed one to three months later. Conversely, interruption of hepatic blood flow for three hours is not compatible with life. In this study, a previously unsuspected resistance of the pig liver to warm ischemia is demonstrated. These findings corroborate and extend those of recent clinical studies in which a similar tolerance of the human liver to prolonged normotherthermic ischemia is reported, thus questioning the necessity for deliberate hypothermia in operations involving the liver.