Treatment Outcomes of PED for Unruptured Aneurysms of Internal Carotid Artery: Comparison of PED-Flex and PED-Shield.

There is a lack of data regarding the safety and effectiveness of implanting the Pipeline Embolization Device with Shield technology (PED-Shield) compared with the previous generation of Pipeline (PED-Flex). This retrospective single-center study aimed to compare treatment outcomes between the PED-Shield and PED-Flex for treating unruptured internal carotid artery aneurysms. The PED-Flex was used in 62 procedures (67 aneurysms, 59 patients) and the PED-Shield in 53 procedures (59 aneurysms, 58 patients). The mean aneurysm diameter was significantly lower in the PED-Shield group than in the PED-Flex group (11.9 ± 7.0 mm vs. 15.2 ± 6.9 mm, p < 0.001). At the 12-month follow-up, the complete angiographic occlusion rate was 72.1% and 72.3% in the PED-Flex and PED-Shield groups, respectively (p = 0.9808). Limited to aneurysms larger than 10 mm, 70.6% and 68.0%, respectively (p = 0.8175). The incidence of more than three high signal intensity areas on diffusion-weighted imaging after treatment was significantly lower in the PED-Shield group than in the PED-Flex group (27.7% vs. 67.7%; p < 0.001). Limited to aneurysms larger than 10 mm, 41.1% and 69.6%, respectively (p < 0.0117). Symptomatic ischemic complications occurred within 30 days of four PED-Flex procedures (6.5%) and one PED-Shield procedure (2.0%) (p = 0.2315). Limited to aneurysms larger than 10 mm, 1.8% and 3.2%, respectively (p = 0.6677). The incidence of mRS score worsening at 6 months was 3.2% and 1.9% in the PED-Flex and PED-Shield groups, respectively (p = 0.6534). The PED-Shield can achieve outcomes equivalent to or better than the PED-Flex. Further large-scale studies are warranted to confirm our findings.