Microsurgery for small arteriovenous malformations of the brain: Results in 110 consecutive patients

OBJECTIVE: To examine the results of surgery in 110 consecutive patients with arteriovenous malformations (AVMs) smaller than 3 cm in diameter. These results are compared with the published results of other microsurgical series as well as with results for patients treated with focused irradiation. METHODS: From January 1989 to November 1998, 121 patients with AVMs smaller than 3 cm were treated at our institution. One hundred ten patients underwent microsurgical removal of their AVMs. The presentation, preoperative neurological status, and postoperative outcome were recorded. Follow-up was complete for all surgical cases. RESULTS: Of the 110 patients, 109 (99%) had angiographically confirmed obliteration of their AVMs. Two patients (1.8%) required reoperation for residual AVM. Two (4.3%) of 46 patients with AVMs in eloquent brain areas experienced worsening of their neurological status after surgery. One (1.6%) of 64 patients was worse neurologically after removal of an AVM in a noneloquent area. CONCLUSION: Microsurgical removal is a safe and effective treatment for the majority of AVMs smaller than 3 cm in diameter. Although the treatment is accompanied by a risk of acute onset of neurological deficits, this tends to be transient in the majority of cases. Furthermore, microsurgical excision of small AVMs offers patients immediate protection from the natural history of their vascular lesions.