Risk of intracranial hemorrhage in glioma patients receiving anticoagulant therapy for venous thromboembolism.

To determine the risk of intracranial hemorrhage in patients with malignant gliomas who are treated with anticoagulant drugs for late postoperative venous thromboembolism, the authors retrospectively reviewed the computerized data base of all patients with primary brain tumors seen at the University of California, San Francisco, over a 9-year period. Of 915 patients 18 years of age or older who had a pathological diagnosis of malignant glioma and an initial Karnofsky performance scale score of 60% or higher, 36 (4%) developed venous thromboembolism 6 to 246 weeks postoperatively and 22 were treated with anticoagulant drugs. Anticoagulant therapy usually consisted of intravenous heparin for 7 to 10 days, followed for at least 3 to 6 months by either subcutaneous heparin (5000 to 8000 U twice daily) or oral warfarin. All patients were closely monitored to ensure control of hypertension, compliance with therapy, maintenance of prothrombin time within the therapeutic range, and early recognition of adverse side effects. No patient had an intracranial hemorrhage. Thus, anticoagulant agents can be safely administered after intracranial operations for malignant gliomas without increased risk of morbidity or mortality if the patients are carefully monitored according to established guidelines.