BackgroundWide necked bifurcation aneurysms (WNBA) are among the most difficult aneurysms to treat. Very low dome-to-neck (DTN) and aspect ratios provide an even greater challenge in the management of WNBAs. We present the safety and efficacy profile for endovascular clip system (eCLIPs) device in the treatment of this subset of WNBAs with very unfavorable morphologies.MethodsIn our case series, 24 patients treated at 12 international centers were taken from a larger prospective voluntary post-marketing registry of 65 patients treated with the eCLIPs device and coiling. Those who had WNBAs at either the carotid or basilar terminus with a DTN ratio ResultsThe eCLIPs device was successfully deployed in 23 cases (96%). One patient (4.2%) died due to guidewire perforation distal to the implant site. No other complications were documented. After a mean follow-up of 15.8 months (range 3-40 months), good radiologic outcomes (modified Raymond-Roy classification (MRRC) scores of 1 or 2) were documented in 20 of 21 patients (95%) with follow-up data. The lone patient with an MRRC score of 3 showed coiled compaction after incomplete neck coverage with the device.ConclusionOur series of patients with aneurysms having adverse DTN and aspect ratios demonstrated that the eCLIPs device has a safety and efficacy profile comparable with currently available devices in the treatment of WNBAs.