Chapter 36 - Fusiform Aneurysms

Abstract

Vertebrobasilar fusiform aneurysms, which represent some of the most daunting lesions treated by cerebrovascular surgeons, are defined by separate inflow and outflow ostia. These aneurysms typically present with brainstem ischemic stroke or compressive symptoms of the brainstem, cerebellum, or cranial nerves. In patients with ischemic stroke or compressive symptoms, the natural history includes steady progression of the aneurysm's presenting signs and symptoms. Although the most time-tested management for fusiform vertebrobasilar aneurysms presenting with compressive symptoms is flow reduction or flow reversal, this strategy relies largely on the presence of adequate collateralization through the posterior communicating arteries. Flow diversion has achieved mixed results, and its use is recommended for cases of compressive symptoms and poor collateralization through the posterior communicating arteries. Anticoagulation is considered the best management for patients with vertebrobasilar aneurysms that present with ischemic stroke and no compressive symptoms. Lastly, we propose an algorithm for symptomatic patients with fusiform vertebrobasilar aneurysms based on presentation.