The Best Treatment Maneuver for Intracranial Arteriovenous Malformation.

To clarify the best treatment maneuver for intracranial arteriovenous malformation (AVM), we examined and reviewed the therapeutic maneuver, clinical course and outcome of 90 patients with intracranial AVM. In all 90 patients intracranial AVM was diagnosed by cerebral angiography. Their clinical symptoms were intracranial hemorrhage in 54 patients, convulsion in 20 patients, other symptoms in 6 patients and asymptomatic in 10 patients. Their clinical courses were checked from each clinical chart and at the latest clinical visit. The mean follow-up period was 3.6 years. Eleven patients were conservatively managed without any surgery or radiosurgery. During the follow-up period (mean: 5.7 years), 3 patients presented with the 4 episodes of intracranial hemorrhage. The hemorrhage rate was 8.02%/patient/year. Nineteen patients were treated with radiosurgery. At 6 months after the radiosurgery, the AVMs were occluded completely in 10 patients, and 4 patients showed the decreased AVM volume to less than half of the original. However, 2 patients showed serious complications: development of multiform glioblastoma and middle cerebral artery (M1 segment) stenosis. Surgical extirpation was performed on 60 patients. Complete obliteration was confirmed on postoperative angiography in all patients. Patients with high-grade AVMs had a worse outcome than those with low-grade AVMs. Morbidity was seen in 4 patients, and mortality was seen in 5 patients. Small-size AVM, without deep venous drainage, and younger age were the factors for good surgical outcome for AVM. AVMs should be treated considering their relatively high bleeding factors, radiosurgical risks and surgical risks. Surgical extirpation should be performed not only with skillful surgical technique but also with supplementary maneuvers such as preoperative embolization, intraoperative angiography, intraoperative ultrasound, functional mapping and hypothermia during perioperative period.