Endovascular interventional therapy and classification of vertebral artery dissecting aneurysms

The current study aimed to summarise the clinical features and classifications of vertebral artery dissecting aneurysms (VADAs) to optimise strategies for endovascular interventional therapy. The clinical features and results of 31 inpatients with VADA were retrospectively analysed. The aneurysms were classified according to their location and association between the aneurysm and posterior inferior cerebellar artery (PICA), and into subtypes according to the developmental state of the contralateral vertebral artery. Different endovascular interventional therapy strategies were selected for each classification. Three types of aneurysm with two subtypes each were identified. An aneurysm located distally to the PICA was termed type I (10/31 patients). Aneurysms with a contralateral vertebral artery were denoted as subtype a (type Ia, 6/31 patients) and aneurysms with hypoplasia of the contralateral vertebral artery were denoted as subtype b (type Ib, 4/31 patients). An aneurysm located at the origin of the PICA was termed type II (13/31 patients), with seven cases classified as IIa and six cases as IIb. An aneurysm located proximally to the PICA was termed type III (8/31 patients), with five cases classified as IIIa and three cases as IIIb. Among the 31 patients, 18 received stent-assisted coiling, two received coiling, 10 received coiling with parent artery occlusion and one patient received conservative treatment. Among the 31 patients with VADA, 21 were occluded completely, nine were partially occluded and one was not occluded. One patient developed a coma following coiling; however, the other 30 patients recovered well. Thus, the classification of an aneurysm based on its location and the developmental state of the contralateral vertebral arteries appears to be an effective and safe approach for the selection of appropriate endovascular interventional therapy strategies.