Systematic Review and Meta-Analysis of Endovascular Therapy Effectiveness for Unruptured Saccular Intracranial Aneurysms

Background: Currently, endovascular treatment of intracranial aneurysms is limited by low complete occlusion rates. The advent of novel endovascular technology has expanded the applicability of endovascular therapies; however, the superiority of novel embolic devices over the traditional Guglielmi detachable coils is still debated. We performed a systematic review of literature that reported the Raymond-Roy occlusion classification (RROC) rates of modern endovascular devices to determine their immediate and follow-up occlusion effectivenesses for the treatment of unruptured saccular intracranial aneurysms. Methods: A search was conducted using electronic databases (PUBMED, Cochrane, ClinicalTrials.gov, and Web of Science). We retrieved studies published between 2000 and 2022, reporting immediate and follow-up RROC rates of subjects treated with different endovascular intracranial aneurysm therapies. We extracted demographic information of the treated patients and their reported angiographic RROC rates. Results: A total of 80 studies from 15 countries were included for data extraction. The RROC rates determined from angiogram were obtained for 21 331 patients (72.5% women, pooled mean age: 58.2 [95% CI]: 56.8-59.6), harboring 22 791 aneurysms. The most frequent aneurysm locations were the internal carotid artery (46.4%, 95% CI: 41.9%-50.9%), the anterior communicating artery (26.4%, 95% CI: 22.5%-30.8%), the middle cerebral artery (24.5%, 95% CI: 19.2%-30.8%), and the basilar tip (14.4%, 95% CI: 11.3%-18.3%). The complete occlusion probability (RROC-I) was analyzed for Guglielmi detachable coils, the Woven EndoBridge, and flow diverters. The RROC-I rate was the highest in balloon-assisted coiling (73.9%, 95% CI: 65.0%-81.2%) and the lowest in the Woven EndoBridge (27.8%, 95% CI: 13.2%-49.2%). The follow-up RROC-I probability was homogenous in all analyzed devices. Conclusion: We observed that the coil-based endovascular therapy provides acceptable rates of complete occlusion, and these rates are improved in balloon-assisted coils. Out of the analyzed devices, the Woven EndoBridge exhibited the shortest time to achieve >90% probability of follow-up complete occlusion (similar to 18 months). Overall, the Guglielmi detachable coils remain the gold standard for endovascular treatment of unruptured saccular aneurysms.