Outcome of Flow Diverters with Surface Modifications in Treatment of Cerebral Aneurysms: Systematic Review and Meta-analysis

Newer flow diverters are enhanced with antithrombogenic surface modifications like the Pipeline Embolization Device with Shield Technology and the Derivo Embolization Device and are purported to facilitate deployment and reduce ischemic events. Our aim was to review the safety and efficacy of surface-modified flow diverters in treating patients with cerebral aneurysms. We used Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review and meta-analysis covering 3 major data bases and gray literature between 2014 and 2019. Two reviewers independently reviewed human studies of surface-modified flow diverters for eligibility based on predetermined criteria. The random effects model and Freeman-Tukey arcsine transformation were used to pool efficacy outcomes (technical success, aneurysm occlusion at 6 and 12 months) and safety outcomes (mortality, morbidity, all ischemia, and serious ischemia). Subgroup analysis was performed to compare outcomes between 2 different flow diverters. Eight single-arm case series involving 911 patients and 1060 aneurysms were included. The median follow-up was 8.24 months. Pooled estimate for technical success was 99.6%, while the aneurysm occlusion at 6 and 12 months were 80.5%, and 85.6%, respectively. Pooled estimates for mortality, morbidity, total ischemia, and serious ischemia rates were 0.7%, 6.0%, 6.7%, and 1.8%, respectively. Most studies were of good quality, and no significant heterogeneity was observed. Limitations include a retrospective, observational design in some studies; heterogeneous and underreported antiplatelet therapy; and potential performance and ecologic bias. Early-to-midterm safety and efficacy for surface-modified flow diverters appear comparable with older devices, especially for small, unruptured anterior circulation aneurysms. Long-term clinical data are required to further corroborate these results.