Abdel Salam Kaleel, MD, MSc

Korja M, Bervini D, Assaad N, and Morgan MK. Role of Surgery in the Management of Brain Arteriovenous Malformations:Prospective Cohort Study. Stroke. 2014

Ruptured brain arteriovenous malformations (bAVM) are one of the most common causes of spontaneous intracerebral hemorrhage (ICH) under 40 years of age with a cumulative long-term risk of major morbidity or death for ruptured AVMs nearing 85%. However, the question remains: what is the best management approach for low and middle-grade bAVMs? Presently, interventional therapy for bAVM includes surgical resection, endovascular embolization, radiotherapy or a combination of these modalities, but the largest trial of unruptured bAVMs, ARUBA, mainly reflected embolization and radiotherapy outcomes, leaving surgical outcomes largely unexplored.

Between January 1989 and May 2014, 779 consecutively enrolled patients were assessed for inclusion in this prospective study, with outcome assessments performed using the modified Rankin scale (mRS) both pre-operatively and at follow up visits. Outcome variables were defined as overall adverse outcome from surgery mRS>1, major adverse outcome mRS>2, perioperative hemorrhage, or “deficit or near miss” (adverse outcome leading to mRS>1 or perioperative hemorhage). The 5-tier Spetzler-Martin grading (SMG) and 3-tier Spetzler- Ponce Class (SPC), measures of surgical risk, were utilized, assigning points for size, the presence of deep venous drainage, and location in “eloquent” brain.

For those patients who underwent surgery, adverse outcomes were seen to increase with increasing SPC grades. The mRS >1 surgical combined adverse outcome rates were 1.4% for SPC A, 19% for SPC B, and 39% for SPC C and adverse outcome rates leading to mRS >2 were 0.6%, 6%, and 19% for SPC A, B, and C, respectively. Complete bAVM resection was achieved in 99.1% of patients with SPC A and B bAVMS. Multiple logistic regression analyses identified possible risk factors for adverse outcomes, including patient age, preoperative hemorrhage, preoperative embolization, largest diameter of bAMV nidus, presence of deep venous drainage, eloquent location, lenticulostriate feeders, and surgical experience. 

The authors concluded that their comprehensive cohort study provided enough evidence that most low and middle grade bAVMs, whether ruptured or unruptured, can be relatively safely treated by surgery. These results however cannot be generalized for high grade, or SPC C bAVMs.