The significance of thrombocytopenia in the development of postoperative intracranial hematoma.

A group of 35 patients undergoing intracranial surgery who exhibited perioperative thrombocytopenia (platelet count less than 150,000/microliters) was studied retrospectively. Of the 35 patients, 14 (40%) developed postoperative intracranial hematomas requiring reoperation and seven (20%) died within 2 weeks after the operation. Analysis revealed that a perioperative platelet count below 100,000/microliters in a patient who failed to respond to platelet transfusions was associated with a higher risk of postoperative hematoma formation. All six patients with this profile developed postoperative hematomas. If the platelet count rose promptly from below 100,000/microliters to a normal level after platelet transfusions, the incidence of hematoma formation decreased dramatically. None of the three patients with this response developed postoperative hematoma. In patients in whom an acute drop in platelet count from the normal range to between 100,000 and 124,000/microliters occurred in the immediate perioperative period, there was a significantly higher change of hematoma formation; this finding has not hitherto been described. Of the 14 patients with this clinical course, eight developed postoperative hematoma after craniotomy for tumors and vascular lesions. This latter observation was substantiated by the fact that thrombocytopenic patients with postoperative hematomas had a greater reduction in platelet count than thrombocytopenic patients with no postoperative hematomas (p = 0.0004).