Partial hepatic grafting: porcine study on critical volume reduction.

Abstract

The safe limit of volume reduction in partial hepatic transplantation, including extracorporeal hepatic resection, remains to be clarified. This study evaluated such a limit and pathologic features associated with transplantation of a less than critical volume. Partial hepatic grafting was performed in a porcine orthotopic autotransplantation model. According to the remnant liver volume, animals were classified into three groups: group 1, 73.8% +/- 4.2% (SD); group 2, 52.6% +/- 6.7%; and group 3, 29.4% +/- 6.7% of the whole liver (n = 5 each). Three-day survival was achieved in five (100%), four (80%), and zero animals, respectively. All animals in group 3 died of graft nonfunction; their intraoperative clearance of the total bile acids was significantly worse than the other groups (p < 0.01). After operation the clearance of the total bile acids and hyaluronic acid, which is selectively cleared by hepatic endothelial cells, was significantly better in group 1 than group 2 (p < 0.01 and < 0.05, respectively). On histologic examination postperfusion biopsy specimens of group 3 exhibited severe ischemic changes and portosinusoidal hyperemia, whereas that of groups 1 and 2 exhibited only mild ischemic damages. Transplantation of less than 30% of expected full liver volume could lead to primary graft nonfunction after partial hepatic grafting.