Awake Surgery for Arteriovenous Malformations (AVM) in Eloquent Area: Risk and Outcome Analysis in the Most Complete Case-Collection

Abstract

Background: Artero-venous malformations (AVMs) located in eloquent area are associated with significant risk of neurological deterioration, especially in patients presenting with unruptured AVMs and minimal or no neurological deficits. Awake-surgery allows a better identification of eloquent gyrus, but its feasibility and application in resection of eloquent AVMs is controversial and mostly limited to small case series.Methods: A total of 31 patients suffering from intracranial AVMs have been operated on in our Department. Patients were stratified into two groups: patients submitted to Asleep Surgery and patients submitted to Awake surgery. We implemented the Awake Group with results from the most complete case series reported in the literature to obtain a complete uni and multivariate analysis of surgical risks and outcome.Results: Awake craniotomy was performed in 19,35% of the AVMs treated in our centre. Considering the reported cases from all other series published in the literature, we obtained a comparison between the asleep group of 25 patients derived from our series and the awake group of 34 patients. No statistically significant differences were identified regarding the risk of postoperative complications, surgical radicality, presence of residual, and need for adjuvant treatment. Interestingly, however, improvement in performance status was more rapid and effective during follow-up in patients treated with awake surgery compared with asleep surgery.Conclusions: In contrast to what is commonly believed, applying awake surgery in this type of lesions does not involve increased intra-operative risks, but rather it seems to determine a greater improvement in the outcome of patients from the thirtieth postoperative day. Awake patients allow for more precise brain mapping and superior clinical neurologic monitoring, which facilitates resection by defining the safe margins without an increased risk.