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

OBJECTIVE: To examine the results of surgery in 110 consecutive patients wi th arteriovenous malformations (AVMs) smaller than 3 cm in diameter. These results are compared with the published results of other microsurgical seri es 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 underw ent microsurgical removal of their AVMs. The presentation, preoperative neu rological status, and postoperative outcome were recorded. Follow-up was co mplete for all surgical cases. RESULTS: Of the 110 patients, 109 (99%) had angiographically confirmed obli teration of their AVMs. Two patients (1.8%) required reoperation for residu al AVM. Two (4.3%) of 46 patients with AVMs in eloquent brain areas experie nced 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 t o be transient in the majority of cases. Furthermore, microsurgical excisio n of small AVMs offers patients immediate protection from the natural histo ry of their vascular lesions.