Interrelation between peripheral platelet count and platelet activation during and after liver surgery in pigs.

The present work was designed to evaluate the functional and ultrastructural changes in platelets during and after major liver resection in healthy pigs as a trial to predict changes occurring in healthy liver donors. Measures to ensure the safety of the donor hepatectomy remain the main concern. Fifteen healthy pigs were prepared for liver resection by right trisegmentectomy. Blood samples were collected as such: one before the operation, two during the operation (one after the mobilization and other after the resection of the liver) and two after the operation (day 7 and day 14). Platelet count and markers of platelet activation, platelet factor 4 and beta-thromboglobulin, were measured. Separated platelets from peripheral blood and the resected liver were examined by electron microscopy. Platelet count was significantly dropped after hepatic mobilization and resection [(P < 0.05) and (P < 0.01), respectively] in comparison to normal level. On day 7, it increased significantly (P < 0.05). On day 14, it increased to become nonsignificantly different from preoperative count. beta-Thromboglobulin and platelet factor 4 were significantly increased after hepatic mobilization and resection [(P < 0.05) and (P < 0.01), respectively]. On day 7, they decreased to become nonsignificantly different from normal level. On day 14, they significantly reincreased (P < 0.01). Electron microscopic examination of platelets revealed all signs of activation after hepatic mobilization and resection. These changes disappeared on day 7 and reobserved on day 14. Liver surgery causes an acute and profound drop in platelet count and an increase in platelet activation. It is necessary to give proper systemic coagulant therapy in addition to platelet transfusion at the end of surgery for 1 week in case of hepatic resection.