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THROMBOPHILIC ABNORMALITIES AMONG PATIENTS WITH CRANIAL DURAL ARTERIOVENOUS FISTULAS

OBJECTIVE Dural sinus thrombosis often accompanies or precedes the development of dural arteriovenous fistulas (DAVFs). Because thrombophilic abnormalities can contribute to sinus thrombosis, we investigated the prevalence of such abnormalities and of venous sinus thrombosis in patients with DAVFs. METHODS Thrombophilic factors were measured in 18 patients with DAVFs treated with embolization at our university hospital. Control data were obtained from patients with unruptured intracranial aneurysms. In addition to sinus occlusion, we investigated prothrombin time, activated thromboplastin time, platelet count, and fibrinogen, platelet, antithrombin III, protein C, protein S, anticardiolipin antibody, anti-cardiolipin β2-glycoprotein-I complex antibody, and D-dimer levels. RESULTS Of the 18 patients with DAVFs, 16 had abnormal D-dimer levels, whereas the mean values for other thrombophilic factors were nearly normal. D-dimer levels were significantly higher in preoperative DAVF patients than in controls. Interestingly, the mean value of D-dimer was higher in patients with sinus occlusion than in those without it (3.33 versus 1.19). D-dimer levels rose after embolization in eight out of 10 serially tested patients, but, on average, the change was not significant. In clinically cured patients treated more than 3 months before, D-dimer was lower than in preoperative patients. CONCLUSION D-dimer is a very sensitive indicator of acute venous thrombosis, suggesting that elevations in patients with DAVFs are likely to reflect sinus thrombosis. D-dimer values decreased and nearly normalized in clinically cured patients during a long-term follow-up period, a finding consistent with completion of thrombosis and cure of the disease. To clarify the correlation between DAVF and sinus thrombosis from the aspect of etiology, we should thoroughly check the variation in the concentration of the thrombophilic factors in the patient with chronic sinus occlusion to know the variation in the fistula formation in the further study.