Microsurgical Treatment of Cerebral Aneurysms After Previous Endovascular Therapy: Single-Center Series and Systematic Review

Background Since its introduction in the early 1990s, endovascular treatment of cerebral aneurysms has had a steady upward trend and is the primary mode of treatment for most intracranial aneurysms. Concurrently, the need for retreatment of aneurysms after previous endovascular treatment has continued to increase, some of which can only be treated with microsurgical techniques. The factors that dictate outcomes in this group of patients are incompletely understood. Objective To study factors contributing to patient outcomes after microsurgical treatment of aneurysms with previous endovascular treatment. Methods The records of the senior author (D.L.B.) since 2002 were retrospectively reviewed for aneurysms treated after previous endovascular treatment. Demographics, treatment details, and imaging were reviewed for all patients. A systematic review of the literature on microsurgical treatment of aneurysms previously treated by endovascular therapy was also conducted. Results A total of 91 patients were identified from the retrospective review. Mean age at the time of initial treatment was 49 ± 12.68 years. Most patients initially presented with subarachnoid hemorrhage before initial endovascular treatment, with only 11 patients (12%) presenting with incidentally discovered lesions. Modified Rankin Scale score at discharge after initial treatment was good (0–3) in 81.4% of cases. Functional outcomes at the last known follow-up showed a modified Rankin Scale score of 0–3 in 77 patients (84.6%). Only aneurysm neck size was found to be a significant predictor of surgical complications (Wald χ 2  = 10.79; P  = 0.0010) with an odds ratio of 2.32 (95% confidence interval, 1.40–3.83) for a 2-mm increase in neck size. Systematic review identified 37 studies who were used to pool data on 370 patients. Although type of surgery was identified as a predictor of poor outcomes, this was significantly confounded by Hunt and Hess grade in the systematic review. Conclusions Favorable outcomes can be obtained even for highly complex cerebral aneurysms that have failed endovascular treatment at high-volume cerebrovascular centers. Initial presentation grade and aneurysm size are important predictors of final patient outcomes.