Endovascular Treatment of Intracranial Blood Blister-like Aneurysms with the Willis Covered Stent: A Single-center Experience and Review of the Literature

Abstract

Abstract Background and purpose To evaluate the safety, feasibility, and effectiveness of the Willis covered stent (WCS) in treating blood blister-like aneurysms (BBAs) and compare it with other stents in the literature. Materials and methods Twenty-one consecutive patients with BBAs treated with the WCS were identified between July 2017 and July 2020. The demographic, clinical, angiographic data and procedural-related complications were collected from the medical records and the operative reports. We comprehensively reviewed the related literature by searching the PubMed, Ovid MEDLINE, and Ovid EMBASE databases. Results The present study included six men and fifteen women, with a mean age of 51.6 years (range 31–70 years). The immediate postoperative angiography demonstrated that the complete occlusion rate was 100%, with no endoleaks. Ophthalmic artery (OA) occlusion occurred in five patients (23.8%). One patient developed delayed stent thrombosis on the third postoperative day. The mean follow-up time was 8.1 months (range 3–21 months). All twenty-one BBAs were occluded entirely, and the patency of the parent arteries was preserved. No aneurysm rupture or recurrence was found, and no retreatment was needed. Two patients developed mild to moderate asymptomatic in-stent stenosis. Twenty patients had an mRS score of zero, and one had an mRS score of one. The final analysis included 138 patients from nine articles plus our cohort. The estimated rate of immediate complete occlusion was 94% (95% confidence interval, 0.30–1.57). Conclusions Our series and the systematic review indicate that treating BBAs with WCSs was relatively safe and efficacious.