Surgical and angiographic localization of spinal arteriovenous malformations

Three cases of spinal arteriovenous malformation are reported which illustrate that localization of intra- and extramedullary components are not always adequately assessed by spinal angiography alone. One large malformation, primarily dorsal to the spinal cord, was not seen on angiography. A second lesion thought to be intramedullary and unresectable as judged by angiography was found at surgery to be primarily dorsolateral and was resected. The third malformation was thought to be extramedullary on angiography, yet had a major intramedullary component at surgery and was not resected. We conclude that surgical exploration of all spinal arteriovenous malformations should be performed despite the angiographic appearance.