Pipeline shield reduces diffusion-weighted imaging-detected ischemia after intracranial aneurysm treatment compared with pipeline flex: a propensity score-matched retrospective cohort study

BACKGROUND: The Pipeline Flex embolization device with Shield technology (PED Shield, Medtronic, Irvine, CA, USA) is a flow diverter designed to reduce thrombogenicity through phosphorylcholine surface modification. Although in vitro and in vivo studies have demonstrated the thrombogenicity reducing effects of this technology, its effectiveness in real-world clinical practice remains unclear. This study aims to compare the number of post-procedure diffusion-weighted imaging (DWI)-positive lesions between PED Flex(Medtronic, Irvine, CA, USA) and PED Shield to assess the impact of surface modification. METHODS: This retrospective cohort study included patients with unruptured intracranial aneurysms treated with PED Flex or PED Shield between April 2016 and March 2024 at a single institution. Propensity score matching was performed to control for confounders, and the number of post-procedure DWI-positive lesions was evaluated as the primary outcome. RESULTS: In total, 148 procedures (132 patients, 138 aneurysms) were included, with 68 (46%) treated with PED Flex and 80 (54%) with PED Shield. Propensity score matching resulted in 47 matched pairs. After matching, the median number of post-procedure DWI-positive lesions was nine (interquartile range (IQR): 3-17) in the PED Flex group and three (IQR: 1-6) in the PED Shield group, with a significantly lower number in the PED Shield group (regression coefficient β = -10.70 [95% confidence interval (CI): -16.23 to -5.16), P<0.001). CONCLUSION: After adjusting for confounders, the PED Shield group had significantly fewer post-procedure DWI-positive lesions than the PED Flex group, suggesting that phosphorylcholine surface modification technology may reduce thrombogenicity in real-world clinical practice.