[Endovascular management and classification of the dissecting aneurysms of the vertebral artery]

Objective: To summarize the classifications and optimize endovascular treatment of the dissecting aneurysms of the vertebral artery (DAVA). Methods: The clinical information of 39 cases of DAVA treated with endovascular methods in our department between January 2007 and September 2016 were analyzed retrospectively.According to the location of the aneurysm in relation to the posterior inferior cerebellar artery (PICA), the aneurysms were classified into three types: type pre-PICA, located proximally to the PICA; type in-PICA, located at the PICA origin; and type post-PICA located distally to the PICA.According to the hemodynamics of the contralateral vertebral artery, the aneurysms were classified into two types: compensatory type: including well-developed contralateral vertebral arteries and a guaranteed posterior circulation blood supply following the occlusion of the ipsilateral vertebral artery; and non-compensatory type: including contralateral vertebral arteries that were hypoplastic and provided an inadequate posterior circulation blood supply following ipsilateral vertebral artery occlusion.The choices of reconstructive or destructive methods were made according to the above-mentioned classification, combined with the consideration of morphological features and onset styles.Reconstructive surgery included stent-assisted coil embolization and the placement of multiple overlapping stents (6 patients). Destructive surgery referred to coil embolization combined with proximal coil trapping of the dissected segment of the parent artery (CE+ PT). Results: A total of 16 patients were type pre-PICA, of which 9 patients were compensatory type and 7 were non-compensatory type.In compensatory type, 4 underwent coil embolization combined with proximal coil trapping of the dissected segment of the parent artery (CE+ PT) and 5 underwent stent-assisted coil embolization (stent/coils). In non-compensatory type, 6 underwent stent/coils and 1 underwent multiple overlapping stents placement (stents). Nine patients were type in-PICA, of which 5 patients were compensatory type and 4 were non-compensatory type. In compensatory type, all patients underwent stent/coils.In non-compensatory type, 2 underwent stent/coils and 2 underwent multiple overlapping stents placement (stents). Fourteen patients were type post-PICA, of which 8 patients were compensatory type and 6 were non-compensatory type.In compensatory type, 6 underwent CE+ PT, 1 underwent stent/coils and 1 underwent stents. In non-compensatory type, 4 underwent stent/coils and 2 underwent stents.Totally, there were 10 underwent CE+ PT, 23 underwent stent/coils and 6 underwent stents.The incidence of perioperative complications was 7.7% (3/39), and the death rate associated with these complications was 5.1% (2/39). Of the 36 patients followed with long-term repeated angiographic examinations, 28(77.8%) patients had complete occlusion.Clinical outcome evaluations were performed using the Modified Rankin Scale and resulted in the following scores: 0-2 for 36 patients, 3-6 for 3 patients. Conclusions: The classifications based on location, hemodynamics, morphological features and onset styles of the DAVA is safe and effective for the choice of the endovascular methods.