Strategies in the treatment of distal cerebellar aneurysms: report of a series of 11 patients.

Background: Distal cerebellar artery aneurysms are rare entities and treatment modalities technically challenging. In recent years, new therapeutic options have emerged through microsurgical and endovascular means.

Objective: Based on a series of 11 cases, we describe combined interdisciplinary treatment strategies and report the outcome in a midterm follow-up interval of 12 months.

Methods: Collection of clinical case data during acute phase and follow-up including standardized angiographic control intervals during follow-up and assessment of the outcome.

Results: 7 of 11 reported cases had flow-related aneurysms based on an underlying arteriovenous malformation (AVM) or dural arteriovenous fistula (DAVF); we found multiple aneurysms in four cases. All patients with flow-related aneurysms presented with subarachnoid hemorrhage (SAH). Only one of four patients in this series without an underlying AVM or DAVF presented with SAH that was attributable to a distal cerebellar aneurysm. In one case, we observed a de novo formation of two flow-associated distal aneurysms (10 years interval). Two patients were treated conservatively, five patients were treated endovascularly, one patient was treated surgically and three patients were treated with combined methods. 9 of 11 patients with initial SAH had a good outcome.

Conclusions: Distal cerebellar aneurysms associated with AVM or DAVF are rare but characterized by a high risk of hemorrhage. The present series indicates that an experienced interdisciplinary team and the combination of available techniques may lead to a reduction of complications and to a better outcome.