Pipeline Shield versus Pipeline Flex for unruptured intracranial aneurysms: a propensity-matched multicenter study.

BACKGROUND: Pipeline Flex Embolization Device with Shield Technology (PED Shield) is designed to reduce the incidence of thrombosis events through phosphorylcholine coating. However, the comparative efficacy and safety of PED Shield and PED/PED Flex remain unclear. METHODS: We conducted a retrospective analysis of a prospectively maintained database at three advanced stroke centers from February 2016 to October 2024. Propensity score matching was employed to adjust for sex, age, hypertension, diabetes, hyperlipidemia, smoking, aneurysm location, morphology, size, coiling and follow-up duration. After matching, perioperative complications and clinical and angiographic outcomes were compared. RESULTS: 1039 patients treated by PED/PED Flex and 172 patients treated by PED Shield were enrolled. For clinical outcomes, 164 pairs were matched. No significant differences were found in total perioperative complications (7.9% vs. 4.9%, p = 0.259) and favourable prognosis (mRS score 0-2, 98.0% vs. 97.5%, p = 0.760) between the PED Shield and PED/PED Flex group. For angiographic outcomes, 121 pairs were matched. No significant differences were observed in complete occlusion (80.2% vs. 73.6%, p = 0.223), significant in-stent stenosis (ISS, ISS rate > 50%) (3.3% vs. 5.0%, p = 0.749) and symptomatic ISS (0.0% vs. 2.5%, p = 0.247) between the PED Shield and PED/PED Flex group. However, PED Shield had a lower incidence of ISS (ISS rate ≥ 25%, 5.0 vs. 14.9%, p = 0.010) at a mean follow-up time of 6-7 months. CONCLUSION: Compared with PED/PED Flex, PED Shield has a lower rate of ISS at a mean follow-up time of 6-7 months. No significant differences are observed in perioperative complications, clinical outcomes, complete occlusion, significant ISS and symptomatic ISS. REGISTRATION: URL: https://www. CLINICALTRIALS: gov ; Unique identifier: NCT06446778.