The comparative effects of total hepatic vascular isolation techniques performed at different durations in rat

Total hepatic vascular exclusion (THVE) leads to massive venous congestion below the level of diaphragm and may promote undesirable hemodynamic disturbances in some patients. Supraceliac aortic clamping during THVE may achieve hemodynamic stability at the price of arterial ischemia. However, the parenchymal injury of venous congestion has been a greater concern than of arterial ischemia in various settings. We hypothesized that supraceliac aortic occlusion during THVE may attenuate the reperfusion injury and improve the outcome that would be acquired after THVE alone.

Rats were randomly assigned to (1) THVE alone, (2) THVE plus aortic occlusion, (3) THVE plus celio-mesenteric arterial occlusion or (4) sham during 30, 45, or 60 min followed by 180 min reperfusion period. Serum enzymes (alanine aminotransferase, lactate dehydrogenase) and creatinine as well as tissue "thiobarbituric acid reactive substances" (TBARS) and histopathology were evaluated. Seven animals per group were followed for survival up to 7 d.

After 30 min, no difference was found in serum enzyme, creatinine and tissue TBARS measures among the isolation methods used. In these, all rats survived to 7 d. However, after 45 and 60 min isolation, aortic occlusion resulted in significant rise in serum enzyme and tissue TBARS measures as well as poor survival (14% and 0%, respectively). In contrast, all rats survived even after 60 min of THVE.

THVE was tolerated up to 60 min with less reperfusion injury and better survival than celio-mesenteric arterial occlusion and supraceliac aortic occlusion in the rat, if needed, aortic clamping should not exceed 30 min. Beyond that, selective celio-mesenteric arterial occlusion may be considered.