Management Outcome of Brainstem Arteriovenous Malformations: The Role of Radiosurgery

Abstract

Management decisions for brainstem arteriovenous malformations (AVMs) are complicated by balancing the risks of treatment and natural progression to hemorrhage. The present study seeks to compare radiosurgery and conservative management outcomes in brainstem AVMs. We performed a retrospective review of patients with brainstem AVM seen at our institution from 1990 to 2013. Patients missing baseline information or those lost to follow-up were excluded. Clinical and angiographic characteristics and subsequent hemorrhagic risk were evaluated according to brainstem AVM location and treatment modality. We identified 30 patients with brainstem AVM with complete data. Mean age was 41.6 ± 20.3 years, and 53.3% (n= 16) were male. Sixteen (53.3%) presented with hemorrhage. Twelve patients (40.0%) were conservatively managed, and 18 were treated. Sixteen (88.9%) of the treated patients underwent radiosurgery, 1 (5.6%) underwent surgery, and 1 (5.6%) underwent embolization only. Average follow-up period was 4.7 ± 5.7 years, and 5 patients (16.7%) experienced recurrent hemorrhage, 3 of whom were in the radiosurgery group and 2 in the conservative group, giving an annual recurrent hemorrhage risk of 3.7% and 4.8%, respectively. Lesion obliteration was achieved in 8 patients (26.7%). Baseline clinical and angiographic factors were similar between the radiosurgery and conservative group. Obliteration was achieved in 43.8% of those treated with radiosurgery (P= 0.008). Despite similar baseline modified Rankin Scale scores, more patients had improvement of modified Rankin Scale score at last follow-up in the radiosurgery group (P= 0.004). Recurrent hemorrhage during follow-up was similar between the 2 groups (P= 0.887). Our results suggest that when patients with brainstem AVM are selected cautiously, radiosurgery may achieve obliteration and symptom relief without increasing subsequent hemorrhage risk.