Objective: A systematic approach to the consideration of various factors on outcome demands a comprehensive grading system for patients with intracranial aneurysms. We have previously identified potential patient- and lesion-specific factors that correlate strongly with outcome after treatment for intracranial aneurysms, and we have developed a comprehensive grading system based on these factors. In this study, we evaluate this grading system in a large series of aneurysm patients treated by surgery and endovascular therapy.
Methods: Between January 1998 and January 2003, ruptured and unruptured aneurysm patients were prospectively entered into a database. Based on our previous study that showed which factors correlated strongly with outcome, data were collected on patient age, aneurysm size, Hunt and Hess grade, and Fisher scale (if presenting with subarachnoid hemorrhage), and a Massachusetts General Hospital grade was then applied. The modified Glasgow Outcome Scale was used for clinical assessment at follow-up, and a binary analysis classified patients into favorable versus unfavorable outcome. Univariate and multivariate analyses for the predictor variables were performed.
Results: One thousand forty-nine aneurysms in 914 patients were identified. Fifty-eight percent (n = 608) of the lesions were unruptured, and 25% (n = 261) were treated endovascularly. For patients treated either surgically or endovascularly, worsening outcome was demonstrated for higher Hunt and Hess grade (surgery, P < 0.001; endovascular, P < 0.001), Fisher scale (surgery, P < 0.001; endovascular, P < 0.001) and for older patients (surgery, P < 0.001; endovascular, P = 0.004). Size of aneurysm had a significant effect on outcome after surgery (P = 0.04), but not after endovascular therapy (P = 0.3). Overall, there was a greater proportion of favorable outcomes for anterior circulation compared with posterior circulation lesions (P < 0.0001). For both the surgical and endovascular subgroups, MGH grade correlated well with clinical outcomes.
Conclusion: The MGH grade is a comprehensive grading system that is easily applied and that allows separation of patients with aneurysms into groups with markedly different outcomes. This information can potentially be helpful in making treatment decisions and when discussing projected outcome before surgical or endovascular intervention of both unruptured and ruptured aneurysms.