Stent-assisted coil embolization followed by a stent-within-a-stent technique for ruptured dissecting aneurysms of the intracranial vertebrobasilar artery

Object. A ruptured dissecting aneurysm of the vertebrobasilar artery (VBA-DA) is a well-known cause of acute subarachnoid hemorrhage (SAH) with a high rate of early rebleeding. Internal trapping of the parent artery, including the dissected segment, is one of the most reliable techniques to prevent rebleeding. However, for a ruptured VBA-DA not suitable for internal trapping, the optimal treatment method has not been well established. The authors describe their experience in treating ruptured VBA-DAs not amenable to internal trapping of the parent artery with stentassisted coil embolization (SAC) followed by a stent-within-a-stent (SWS) technique. Methods. Eleven patients - 6 men and 5 women with a mean age of 48 years and each with a ruptured VBA-DA not amenable to internal trapping of the parent artery - underwent an SAC-SWS between November 2005 and October 2007. The feasibility and clinical and angiographic outcomes of this combined procedure were retrospectively evaluated. Results. The SAC-SWS was successful without any treatment-related complications in all 11 patients. Immediate posttreatment angiograms revealed complete obliteration of the DA sac in 3 patients, near-complete obliteration in 7, and partial obliteration in 1. One patient died as a direct consequence of the initial SAH. All 10 surviving patients had excellent clinical outcomes (Glasgow Outcome Scale Score 5) without posttreatment rebleeding during a followup period of 8-24 months (mean follow-up 15 months). Angiographic follow-up at 6-12 months after treatment was possible at least once in all surviving patients. Nine VBA-DAs showed complete obliteration; the other aneurysm, which had appeared partially obliterated immediately after treatment, demonstrated progressive obliteration on 2 consecutive follow-up angiography studies. There was no in-stent stenosis or occlusion of the branch or perforating vessels. Conclusions. The SAC-SWS technique seems to be a feasible and effective reconstructive treatment option for a ruptured VBA-DA. The technique may be considered as an alternative therapeutic option in selected patients with ruptured VBA-DAs unsuitable for internal trapping of the parent artery.