Sylvian fissure arteriovenous malformations: long-term prognosis and risk factors

Background and objective: Sylvian fissure arteriovenous malformations (AVMs) are among the most challenging AVMs to manage surgically. The estimates of their risk factors and prediction of their long-term prognosis are crucial for clinical decision-making. The authors conducted a retrospective review to patients with sylvian AVMs treated microsurgically to evaluate the risk factors associated with long-term prognosis. Methods: Forty-one patients with sylvian fissure AVMs treated microsurgically between June 2009 and December 2011 were retrospectively reviewed with a mean follow-up time of 23 months (range 6–35 months). Chi-square test was utilized to compare proportions and rank-sum test to compare ordinal materials. Odds ratios (ORs) were used to assess risk factors associated with postoperative short-term outcome and long-term adverse outcome (mRS scores 3–6). Results: One patient died in 1 month after surgery. Eighteen (43.9 %) patients had postoperative transient neurological deterioration. Good outcomes (mRS scores 0–2) were observed in 29 (72.5 %) patients in the follow-up. From the multiple logistic regression, a history of AVM bleeding and deep venous drainage increase the risk of postoperative transient neurological deterioration, with OR = 8.211 and OR = 4.869, respectively. A history of AVM bleeding was a risk factor for long-term adverse outcome, with OR = 7. Conclusions: Despite different Sugita classification subtypes, sylvian fissure AVMs’ long-term results with microsurgical resection are better than expected; a history of AVM bleeding is a risk factor for postoperative temporary neurological deterioration and for long-term adverse outcome, while the AVM deep venous drainage is a risk factor only for temporary neurological deterioration.