未破裂脳動静脈奇形の治療方針とその成績(<特集>未破裂脳動静脈奇形)  [in Japanese] Strategy and Outcome in Patients with Unruptured Cerebral AVM(<Topics>Unruptured Arteriovenous Malformations)  [in Japanese]

The treatment of unruptured cerebral arteriovenous malformation (AVM) is still controversial. We have been treating these patients according to the Spetzler & Martin (S&M) grading system. We retrospectively evaluated the outcomes of 46 unruptured AVM patients and also evaluated the bleeding rate during follow-up period. Recently we also started performing functional MRI, trac-tography, and 3-dimensional (3D) angiography for these patients before treatment. In 18 of 22 patients in S&M Grade I and II, AVMs were surgically removed and the outcome was good. Six of 9 patients in S&M Grade IV and V, were conservatively treated. In patients in S&M Grade III, various treatments were performed according to the location of the AVM, but all their outcomes were favorable. The rate of permanent surgical complications was 15.3% in 26 unruptured AVM patients. Based on our treatment results, aggressive treatment should be performed in patients with S&M Grade I and II. However, treatment decisions must be carefully considered based on functional MRI, tractography of AVM, and 3D angiography.