Management of aneurysms of the vertebral artery-posterior inferior cerebellar artery complex.

Aneurysms of the vertebral artery (VA) and posterior inferior cerebellar artery (PICA) account for only about 3% of all diagnosed intracranial aneurysms. The surgical therapy of these aneurysms is complex and difficult due to the close topographical relationship between the neurovascular structures. Here, we report upon 27 patients with 29 such aneurysms. Of these, 22 patients (81%) were hospitalized because of a subarachnoid hemorrhage. Sixteen of these patients (72%) had an additional intraventricular hemorrhage. Twenty-one patients (78%) were surgically treated for their aneurysms, three of them also for an associated arteriovenous malformation. Aneurysms of the VA and the proximal PICA were exposed via a transcondylar (n = 11) or lateral suboccipital (n = 3) approach, those originating from the distal PICA via a paramedian suboccipital (n = 7) route. Endovascular therapy was used in three patients. A patient with a fusiform aneurysm of the vertebrobasilar junction was treated with a ventriculoperitoneal shunt only. Three aneurysms with a complex morphology were not treated. Of the patients operated upon, two died postoperatively due to vasospasm. Two other patients developed an incomplete dorsolateral medullary syndrome. One individual was lost for follow-up. The median follow-up period was 4.6 years (range 3-86 months). Both, the overall mortality (2/27) and morbidity (2/27) were 7.5%, respectively. Our results show that even complex vascular lesions of the posterior fossa can be treated with a satisfactory long-term outcome in the majority of our patients (85%). The multimodal management and an individually tailored microsurgical approach are key issues for the treatment of such aneurysms.