Objective: The presence of cortical venous reflux is recognized as an indicator of increased risk of intracranial hemorrhage and neurological deficits in cranial dural arteriovenous fistulas. Its disconnection is well accepted as a treatment for fistulas with direct cortical reflux (Borden type III), but the role of disconnection of the cortical venous reflux in the management of fistulas that involve the venous sinus and cortical venous reflux (Borden type II) is still a matter of debate. We analyze the experience of the Toronto Brain Vascular Malformation Study Group in the management of these lesions by simple cortical venous reflux disconnection and its impact in the future risk of bleeding.
Methods: From June 1984 to August 2004, 347 patients with dural arteriovenous fistulas, either cranial or spinal, were evaluated by the group. Fifty-three patients had a Borden type II dural arteriovenous fistulas. Twenty-five patients were submitted to simple surgical disconnection of the dural arteriovenous fistulas, two were lost for follow-up. There were 15 females and 8 males, with mean age at diagnosis of 53.9 years. Follow-up time was 112.6 patient-years, from 2 months to 11 years, mean 4.9 years. Endovascular treatment was attempted in all patients, but no disconnection was possible. Twelve patients had their fistulas completely occluded by endovascular means, but are not analyzed here. There were four complications from the 93 endovascular procedures, and 3 from the 27 surgical procedures. Two patients required a repeated surgical procedure. No episode of intracranial hemorrhage or worsening neurological deficit was seen after disconnection of the cortical venous reflux in 4.9 years of follow-up.
Conclusion: Simple surgical disconnection of the cortical venous reflux maybe an option in the management of patients with Borden type II dural arteriovenous fistulas. This procedure is a much smaller surgical undertaking and is associated with fewer complications than attempts to resect or pack the whole fistula, especially if located in the skull base.