Platelet aggregability after splenectomy in patients with normosplenism and hypersplenism.

The relationship between platelet count and aggregability was serially evaluated after splenectomy in patients with normosplenism and hypersplenism, and the results were compared with those found in patients undergoing only upper abdominal surgery. The preoperative count and aggregability of platelets were significantly suppressed in patients with cirrhosis of the liver, idiopathic portal hypertension, and prehepatic portal obstruction. However, the platelet aggregability of these patients markedly increased in accordance with the platelet counts after splenectomy. In the patients with normal splenic function preoperatively, splenectomy caused a simultaneous increase in platelet count and aggregability. The platelet function was not always reflected by the count in the patients with idiopathic thrombocytopenic purpura. On the other hand, in the control patients undergoing only laparatomy the platelet count substantially increased two weeks after operation, but platelet aggregability did not differ from the preoperative value. The present results suggest that additional factors for thromboembolism such as hypotension, acidosis, or stagnant blood flow should be avoided during the peak period of reactive thrombocytosis after splenectomy, and that an appropriate use of anticoagulants or inhibitors of platelet aggregation is recommended if and when necessary.