Objective: Posterior circulation aneurysms can be difficult lesions to treat surgically, and they have potential for high morbidity and mortality, particularly in elderly patients or those in poor neurological condition. In an effort to improve outcomes, our combined neurosurgical and neuroendovascular unit has used both surgical clipping and endovascular coiling techniques to treat posterior circulation aneurysms. Patients considered at high risk for surgery were managed with endovascular treatment.
Methods: From 1990 to 1998, 197 posterior circulation aneurysms in 189 patients were treated in our combined neurovascular unit. Of these aneurysms, 128 were ruptured, 63 were unruptured, and 6 had a distant history of rupture in patients who came to our center for delayed or repeat treatment. A total of 132 aneurysms were treated with surgical clipping (85 ruptured, 46 unruptured, and 1 with distant history of rupture) and 65 aneurysms were treated with endovascular coiling (43 ruptured, 17 unruptured, and 5 with distant history of rupture). Dissecting aneurysms of the vertebral or posteroinferior cerebellar arteries or aneurysms treated with proximal (Hunterian) occlusion were excluded from this analysis. Surgical risk was assessed using a previously described system (Massachusetts General Hospital [MGH] grade), which incorporates age, Hunt and Hess grade, size of lesion, and Fisher grade.
Results: Overall clinical outcomes at 1 year of follow-up were 77.2% excellent or good, 10.2% fair, 4.1% poor, and 8.6% dead. Surgical treatment resulted in 95.6% complete aneurysm occlusion and 4.4% with residual aneurysm after surgical treatment, whereas endovascular treatment resulted in 32.3% complete occlusion, 26.2% with residual aneurysm, and 41.5% with partial occlusion. In most cases, however, treatment with Guglielmi detachable coils (Boston Scientific/Target, Fremont, CA) was performed for palliation rather than complete radiographic occlusion. Outcome was closely associated with MGH grade with either treatment modality. Excellent/good outcomes were achieved in 96, 92.3, 82.9, 46.2, and 0% of surgically treated patients with MGH Grades of 0, 1, 2, 3, and 4, respectively. In comparison, excellent/good outcomes were achieved in 100, 84.2, 61.9, 0, and 50% of endovascularly treated patients with MGH Grades of 0, 1, 2, 3, and 4, respectively.
Conclusion: A combined surgical and endovascular approach to posterior circulation aneurysms can achieve good outcomes in high-risk surgical patients treated by use of coiling techniques.