Comparison of Pipeline Embolization Device and Flow Re-Direction Endoluminal Device Flow Diverters for Internal Carotid Artery Aneurysms: A Propensity Score-Matched Cohort Study

Background Flow diversion has become an accepted endovascular treatment modality for intracranial aneurysms. Studies comparing different types of flow diverters are currently lacking. Objective To perform a propensity score-matched cohort study comparing the Pipeline Embolization Device (PED; Medtronic, Dublin, Ireland) and Flow Redirection Endoluminal Device (FRED; MicroVention, Aliso Viejo, California). Methods Aneurysms of the internal carotid artery proximal to the communicating segment treated with PED at 2 neurovascular centers in the United States were matched with aneurysms treated in the European FRED study using propensity scoring. Aneurysms treated in the setting of subarachnoid hemorrhage were excluded from matching. Occlusion rates and complications were evaluated. Results Two hundred twenty-one internal carotid artery aneurysms were treated with PED and 282 with FRED. Propensity score matching controlling for age, sex, aneurysm size, location, number of flow diverters, and adjunctive coiling resulted in 55 matched pairs. Median angiographic follow-up was nonsignificantly longer for FRED compared to PED (12.2 vs 7.5 mo, P = .28). The rate of complete occlusion did not differ between flow diverters (80% vs 80%, P > .99). Functional outcome and complications were comparable for PED and FRED. Conclusion Propensity score-matched analysis of PED and FRED for internal carotid artery aneurysms revealed comparable angiographic complete occlusion and complication rates. Whether FRED has an advantage in terms of near complete aneurysm occlusion warrants further investigation. Limitations include the retrospective design and lack of an independent assessment of radiographic outcome in a core-laboratory and functional outcomes, among others, and the results should be interpreted as such.