Transdural blood supply to cerebral arteriovenous malformations adjacent to the dura mater.

BACKGROUND AND PURPOSE Subpial cerebral arteriovenous malformations (AVMs) can develop a transdural arterial blood supply. The relationships between AVM volume, patient age, embolization and prior hemorrhage, and the frequency of transdural blood supply were investigated. METHODS During 1997-1999, 105 consecutive patients with 107 AVMs adjacent to the dura mater were treated with embolization at one center. One of the authors, who was not directly involved in the treatment, retrospectively reviewed the angiograms. Patient histories were collected from hospital records. RESULTS Angiograms obtained before the first embolization included a selective injection into the dural arteries in 86 (80%) AVMs. Thirty-six (42%) of those had transdural blood supply. The frequency increased with AVM volume and patient age but not with intracranial hemorrhage. Follow-up angiograms obtained subsequent to at least one embolization were available in 32 patients who had no transdural blood supply at the first examination. In eight (25%) patients, a transdural blood supply developed during a mean treatment time of 12 months. CONCLUSION A transdural blood supply is common in AVMs adjacent to the dura mater. The frequency increases with AVM volume and patient age. Intracranial hemorrhage does not seem to be a predisposing event. Transarterial embolization appears to induce factors that promote the development of a transdural blood supply.