Endovascular strategies for management of intradural vertebral artery dissecting aneurysms

Objective: Endovascular treatment of vertebral intradural dissecting aneurysms is complex and requires different strategies for each case. The current study aims to classify these aneurysms for an easy selection of optimal strategies for endovascular therapy. Materials and Methods: This study is a retrospective evaluation of 10 patients harbouring a vertebral intradural dissecting aneurysm (including 6 female and 4 male patients). The clinical, procedural, and angiographic data were evaluated. Results: Nine patients presented with acute subarachnoid hemorrhage and 1 with acute-onset headache. The aneurysms were classified into two types, depending on the developmental state of the contralateral vertebral artery: Dominant (A) and hypoplastic (B). Type A (n = 7) group was further divided into three subtypes on the basis of location of the aneurysm in relation to the posterior inferior cerebellar artery (PICA): aneurysm proximal to the PICA, Type I (n = 3); involving the PICA, Type II (n = 2); and, distal to the PICA, Type III (n = 2). Internal trapping was done for 4 patients in this group, 2 patients with aneurysm involving the PICA underwent proximal occlusion and 1 patient underwent stent-assisted coiling since he refused to undergo vertebral artery sacrifice. B Type patients (n = 3) were treated with reconstructive endovascular management. No symptomatic complication was seen in the patients with trapping. Antiplatelet medication-related complication was seen in 2 patients who underwent stent-assisted coiling. Clinical outcome at the time of discharge was good [modified Rankin score (mRS) 0-2] in 8 and poor (mRs > 2) in 2 patients. At follow-up visit, one patient had developed severe cognitive impairment but was independent in activities of daily living. Conclusion: The classification of vertebral artery aneurysms based on their location and on the status of the contralateral vertebral artery appears to be an effective method for the selection of safe and appropriate endovascular therapy.