SURGICAL INTERRUPTION OF LEPTOMENINGEAL DRAINAGE AS TREATMENT FOR INTRACRANIAL DURAL ARTERIOVENOUS-FISTULAS WITHOUT DURAL SINUS DRAINAGE

Intracranial dural arteriovenous fistulas (AVFs) have been recognized as acquired lesions that can behave aggressive ly depending on the pat tern of venous drainage. Based on the type of venous drainage, they ca n be classified as fistulas drained only by venous sinuses, those drai ned by venous sinuses with retrograde flow in arterialized leptomening eal veins, and fistulas drained solely by arterialized leptomeningeal veins. Serious symptoms, including hemorrhage and focal deficit, are r elated to the presence of arterialized leptomeningeal veins. In this p aper, the authors report a consecutive series treat ed between 1988 an d 1993 of 20 cases of intracranial dural AVFs with ''pure leptomeninge al drainage.'' All patients under went surgical interruption of the le ptomeningeal draining veins. Based on the arterial supply, nine patien ts were managed by direct surgery, whereas 11 patients were prepared f or surgery by means of preoperative arterial embolization. Radioanatom ical cure of the fistula and good neurological recovery were achieved in 18 cases. Complete obliteration of the fistula was documented angio graphically in two cases, but fatal hemorrhage occurred, probably due to partial thrombosis of the venous drainage. Based on this experience , the authors believe that surgical interruption of the draining veins is the best treatment option for intracranial dural AVFs. However, su rgical results may be affected by the extension of postoperative throm bosis, which in turn may be related to the degree of preoperative veno us engorgement.