Application of the Willis Covered Stent in the Treatment of Blood Blister-Like Aneurysms: A Single-Center Experience and Systematic Literature Review

Abstract

The purpose of the present study was to introduce our initial experience with the use and feasibility of the Willis covered stent (WCS) in the treatment of blood blister-like aneurysms (BBAs) and to present a systematic review of the reported data on the treatment of BBAs with covered stents. Fourteen consecutive patients with BBAs had been treated with WCSs at West China Hospital from January 2015 to August 2017. The patient medical records, angiographic findings, and endovascular treatment reports were reviewed by interventional neuroradiologists and neurosurgeons to obtain relevant clinical and angiographic information. We conducted a systematic review of all reports of BBAs treated with covered stents. We searched the reported data using PubMed, Embase, China National Knowledge Infrastructure, and Wanfang databases and commercial Internet search engines. We included BBAs located at nonbranching portions of the internal carotid artery (ICA). The present study included 9 men and 5 women, with a mean age of 54.5 years (range, 30-79). All patients had complete occlusion found on immediate postoperative angiography. The ophthalmic artery was occluded in 2 patients (14.3%). No mortality or morbidity had occurred during the procedure. Two patients (14.3%) experienced a mild recurrence. One patient (7.1%) had developed mild in-stent stenosis. The clinical follow-up period was 6-15 months for all the patients. Of the 14 patients, 11 (78.6%) had a modified Rankin scale score of 0, and 1 (7.1%) had a modified Rankin scale score of 1 during the follow-up period. One patient (7.1%) experienced subarachnoid hemorrhage at 7 days postoperatively and had died 10 days after surgery. None of the patients experienced visual defects. Of our 14 patients, 13 (92.9%) survived, as determined by outpatient department visits or telephone interviews. A total of 8 reports, including 38 patients, met our criteria. Of these 38 patients, 37 (97.3%) had successful delivery to the diseased ICA, and 34 (89.5%) had experienced complete occlusion during follow-up. The overall rate of complete occlusion was 83.0% (95% confidence interval, 68%-91%). Patients with ruptured BBAs treated with WCSs can achieve satisfactory clinical results. Therefore, for BBAs, the implementation of the WCS could be safe and feasible. This strategy could be a promising option for this type of high-risk aneurysm. However, patients with tortuous ICAs or aneurysms close to essential branch arteries should be carefully evaluated before the WCS is used.