Management of residual dysplastic vessels after cerebral arteriovenous malformation resection: Implications for postoperative angiography

OBJECTIVE: The verification of surgical resection of cerebral arteriovenous malformations (AVMs) relies on angiography. Abnormal vasculature often is identified after removal of the AVM. Differentiation of dysplastic feeding vessels that resemble the neovascularity of moyamoya disease, as distinct f rom residual AVM, is crucial for preserving critical brain areas. We review a large experience with immediate postoperative angiography after AVM rese ction and discuss the implications for management of abnormal dysplastic ve ssels discovered after AVM resection. METHODS: Beginning in 1992, 86 consecutive patients with AVMs underwent ope rations by standard protocol for immediate postoperative angiography under the same general anesthetic. Angiographic interpretation dictated admission to the intensive care unit or return to the operating room for further res ection. RESULTS: In 78 patients, the angiogram revealed complete resection. Two pat ients were returned to the operating room, one for residual malformation wi th an early draining vein, and one for resection of residual dysplastic ves sels. There was one postoperative hemorrhage in a patient whose postoperati ve angiogram was falsely negative for AVM. Six patients with residual dyspl astic vessels mimicking residual AVM, but without an early draining vein, w ere managed conservatively. Delayed follow-up angiography demonstrated spon taneous involution of these abnormal vessels in all of these patients. CONCLUSION: Residual dysplastic feeding vessels resembling the neovasculari ty of moyamoya disease but not associated with an early draining vein do no t necessarily represent residual malformation after AVM resection. The abno rmal vessels will proceed to complete spontaneous resolution. Given the dif ficulty of interpreting intraoperative angiography, immediate postoperative angiography may be a viable alternative after AVM resection.