Outcome for middle cerebral artery aneurysm surgery

Objective: To assess in depth the variables contributing to adverse surgical outcome for repair of unruptured middle cerebral artery aneurysms. Methods: Prospectively collected data between October 1989 and June 2009 were examined retrospectively. Putative risk factors were investigated with univariate and multivariate logistic regression analyses. Results: In this study, 263 patients (339 aneurysms) underwent surgical clipping in 280 operations for unruptured middle cerebral artery aneurysms. The overall surgical mortality and morbidity rate was 5% (95% confidence interval [CI], 2.9-8.3). Multivariate logistic analysis of risk factors revealed that age and aneurysm size were independent predictors of surgical outcome. Patients < 60 years of age with an aneurysm ≤ 12 mm constituted a low-risk group with a procedure-related combined mortality and morbidity of 0.6% (95% CI, 0-3.8). Patients < 60 years of age with an aneurysm > 12 mm had a procedure-related combined mortality and morbidity of 7.4% (95% CI, 1-24.5). Patients ≥ 60 years of age with an aneurysm of ≤ 12 mm had a procedure-related combined mortality and morbidity of 9.3% (95% CI, 4.3-18.3). Patients ≥ 60 years of age with an aneurysm > 12 mm had a procedure-related combined mortality and morbidity of 22.2% (95% CI, 8.5-45.8). Conclusion: Age and size of aneurysm were the only 2 independent predictors of surgical outcome.