Ruptured dissecting aneurysms arising from non-vertebral arteries of the posterior circulation: endovascular treatment perspective.

PURPOSE Most intracranial dissecting aneurysms involve the posterior circulation, and the intradural segment of the vertebral artery is affected in majority of these. The aim of this report is to summarize the results of endovascular treatment in patients with ruptured dissecting aneurysms of the non-vertebral posterior circulation. MATERIALS AND METHODS During the past six years, the medical records of 23 patients with subarachnoid hemorrhage related to dissecting aneurysm arising from non-vertebral arteries of the posterior circulation were reviewed retrospectively. RESULTS The locations of the aneurysms were as follows: seven in the posterior cerebral artery, five in the superior cerebellar artery, six in the basilar artery trunk, and five in the posterior inferior cerebellar artery. Two basilar artery aneurysms were treated in the chronic stage with stent-assisted coil embolization. In the remaining patients, the aneurysm was coiled with or without parent vessel occlusion in the acute stage. One patient re-bled and died 20 days after initial treatment. At follow-up, recanalization had occurred in two patients, whose aneurysms were re-embolized successfully. Overall, three patients had permanent neurological sequelae, two had transient neurological sequelae, and one patient died. CONCLUSION Embolization with or without parent artery occlusion is feasible with an acceptable morbidity and mortality rate in the treatment of dissecting aneurysms confined to non-vertebral arteries of the posterior circulation.