Distal aneurysms of the vertebrobasilar system. A report of five cases

INTRODUCTION: Aneurysms distal to the circle of Willis are uncommon. Among the rarest of such aneurysms are those found in the territory of the vertebrobasilar artery. OBJECTIVE: To describe clinico-radiological aspects and the clinico-surgical evolution of five patients with distal aneurysms of the cerebellar arteries. PATIENTS AND METHODS: Five patients (2.5%), with aneurysms of the cerebellar arteries, of a total of 194 patients with cerebral aneurysms admitted to our hospital between 1995 and 1998. RESULTS: All patients presented with subarachnoid hemorrhage. One patient also had an arteriovenous malformation (AVM). One patient refused surgical treatment, three were treated surgically and one using the endovascular approach. The patient who was successfully treated using the endovascular approach to an aneurysm of the antero-inferior cerebellar artery, and who also had an AVM had a further episode of bleeding following partial embolization of his AVM. The patients who were treated surgically and the one who refused surgical treatment made good progress. CONCLUSIONS: A multidisciplinary approach to the treatment of cerebral aneurysms is essential. Microsurgical techniques are very useful, especially in peripheral aneurysms.