Difference in the cumulative incidence of aneurysmal occlusion by Flow Re-direction Endoluminal Device and Pipeline Embolization Device in the treatment of unruptured internal carotid artery aneurysms: A propensity score-matched cohort study

AbstractObject:The introduction of flow diverters (FDs) has represented a paradigm shift in the management of unruptured cerebral aneurysms (UCA). Flow Re-Direction Endoluminal Devices (FREDs) and Pipeline Embolization Devices (PEDs) have gained widespread popularity. We aimed to investigate the cumulative incidence of aneurysm occlusion.Methods:A total of 195 patients with 199 UCAs were analyzed retrospectively. The outcomes were aneurysmal occlusion during the follow-up, a modified Rankin Scale score of 0–2 at 90-day, additional treatment, and major stroke, and steno-occlusive events of FD. Propensity score-matched analysis was performed controlling for age, sex, aneurysmal size, and location of internal carotid artery (ICA) aneurysm. Non-ICA aneurysms were excluded from matching.Results:During the follow-up period (median, 366 days), complete and satisfactory aneurysmal occlusions were observed in 128 (68%) and 148 (78%) of 189 UCAs in unmatched cohort. The 142 (71 each) propensity score-matched cohort was complied. The FRED group had a higher cumulative incidence of ICA aneurysm occlusion (complete: HR 2.7, 95% CI 1.4–5.1, p=0.0025; satisfactory: HR 2.4, 95% CI 1.1–5.2, p=0.025). Proportion of additional treatment was significantly smaller in the FRED group (OR 0.077, 95% CI 0.010-0.57, p=0.0007). Other outcomes showed no significant differences.Conclusion:Propensity score-matched analysis showed that FRED had a higher cumulative incidence of aneurysmal occlusion in the treatment of unruptured ICA aneurysms. Whether a cumulative incidence of aneurysmal occlusion may differ by the type of FDs warrants further investigation.