Introduction: Recent studies have questioned the utility of surgical resection of unruptured brain arteriovenous malformations (bAVMs). We performed an assessment of outcomes and complications of surgical resection of low-grade bAVMs (Spetzler-Martin Grade I or II) at a single high-volume neurosurgical center.
Methods: We reviewed all unruptured low-grade bAVMs treated with surgery (with or without preoperative embolization) between 01/2004 and 01/2014. Stroke rate, mortality, and clinical and radiographic outcomes were examined.
Results: Of 95 patients treated surgically, 85 patients (25 Grade I, 60 Grade II) met inclusion criteria, and all achieved radiographic cure postoperatively. Ten patients (11.8%) were lost to follow-up; the mean follow-up of the remaining 85 was 3.3 years. Three patients (3.5%) with Grade II bAVMs suffered stroke; no patients died. Although 20 patients (23.5%) had temporary postoperative neurological deficit, only 3 (3.5%) had new clinical impairment (mRS [modified Rankin Scale] score = 2) at last follow-up. Eight of the 13 patients (61.5%) with preexisting clinical impairment had improved mRS scores of 0 or 1; and 17 of 30 patients (56.7%) with preoperative seizures were seizure-free without antiepileptic medication postoperatively. No significant differences existed in stroke rate or clinical outcome between Grade I and II patients at follow-up (Fisher exact test, P = .55 and P > .99, respectively).
Conclusions: Surgical resection of low-grade unruptured bAVMs is safe, with a high rate of improvement in functional status and seizure reduction. Although transient postoperative neurological deficit was observed in some patients, permanent treatment-related neurological morbidity was rare.
Patient Care: Recent trials of challenged the notion that any brain AVMs should be treated. By reviewing a large modern series of low-grade AVMs treated by surgical resection with or without preoperative embolization, we have been able to show that our approach to these lesions is safe and effective. This is a valuable contribution to the cerebrovascular community as we seek answers to questions of treatment indication in brain AVMs and formulate future studies/trials.
Learning Objectives: 1. Describe the treatment options for low-grade AVMs
2. Describe the outcomes and complication rates for surgical resection of low-grade AVMs
3. Describe the rate of seizure improvement following surgical resection
4. Describe future research questions regarding management of low-grade AVMs