Distal aneurysm of the rostral duplicate anterior inferior cerebellar artery feeding an associated dural arteriovenous malformation: case report and review of the literature

Endovascular treatment of AICA flow dependent aneurysms. A report of three cases and review of the literature

Peripheral anterior inferior cerebellar artery (AICA) aneurysms are rare, accounting for less than 1% of all cerebral aneurysms. To our knowledge 34 flow-related cases including the present study have been reported in the literature. Three patients harbouring four flow dependent aneurysms were referred to our institution. Two patients presented with subarachnoid hemorrhage, one presented with cerebellar manifestations. They were all treated by endovascular embolization of the aneurysm as well as the parent artery using liquid embolic material. Two cases were embolized using NBCA, Onyx was used in the third case. No bleeding or rebleeding were encountered during the follow-up period which ranged from five to nine months. One patient developed facial palsy, cerebellar symptoms and sensorineural hearing loss. The remaining two cases did not develop any post treatment neurological complications. Endovascular management of flow-dependent AICA aneurysms by parent artery occlusion is feasible and efficient in terms of rebleeding prevention. Post embolization neurological complications are unpredictable. This depends upon the adequacy of collaterals from other cerebellar arteries.

Interdisciplinary clinical management of high grade arteriovenous malformations and ruptured flow-related aneurysms in the posterior fossa

Posterior fossa arteriovenous malformations are rare entities and treatment modalities technically challenging. In recent years new therapeutic options have emerged through microsurgical and endovascular means. Based on a series of six cases we describe combined interdisciplinary treatment strategies and report the outcome in a midterm follow-up interval of 12 months. Clinical case data were collected during acute phase and follow-up including standardized angiographic control intervals during follow-up and assessment of the outcome. Treatment options included endovascular techniques as well as microsurgical techniques. All reported cases had SAH based on ruptured flow-related aneurysms in posterior fossa AVM; three out of six had multiple aneurysms. In one case we observed a de novo formation of two flow-associated distal aneurysms in an interval of ten years. Two patients were treated only endovascularly, one patient only surgically and three patients with combined methods. Five out of six patients had a good outcome (GOS 4 or 5). One died in the acute phase. Infratentorial AVMs are rare but characterized by a high risk of rupture and SAH, especially in conjunction with flow related aneurysms, which are predictors of poor outcome. The anatomic conditions of the posterior fossa may lead quickly to life-threatening complications due to mass effects. The present study indicates that treatment strategies in the acute phase should focus on flow-related aneurysms, followed by an elective AVM embolization and ectomy whenever possible. An experienced interdisciplinary team and the combination of techniques contribute to a reduction of complications and to a better outcome.