Pipeline Embolization device for the treatment of unruptured intracranial saccular aneurysms: a systematic review and meta-analysis of long-term outcomes

Introduction: The pipeline embolization device (PED) is commonly used for intracranial aneurysm treatment. While its effectiveness for certain types of aneurysms is well-established, its efficacy for saccular aneurysms remains controversial. We aimed to assess the long-term outcomes of PED treatment for unruptured intracranial saccular aneurysms.

Methods: Systematic review and meta-analysis were conducted following PRISMA guidelines. Studies with at least one year of follow-up after PED treatment for saccular aneurysms were included. The primary endpoint was angiographic aneurysm occlusion at long-term follow-up (≥ 12 months), and the secondary outcome was long-term complications. We conducted a meta-regression analysis to explore potential sources of heterogeneity across studies.

Results: Eleven studies of 797 patients with 963 aneurysms were included. Long-term angiographic occlusion rate was 85% (95% CI, 77-91%; p < 0.01), symptomatic ischemic stroke rate was 1% (95% CI, 0-3%; p < 0.01), rupture rate was 1% (95% CI, 0-2%; p = 0.02), and intracranial hemorrhage (ICH) rate was 0.2% (95% CI, 0-1%; p = 0.11). Meta-regression analysis revealed a non-significant decreasing trend per year for aneurysmal occlusion, ischemic stroke rate, delayed aneurysmal rupture, and ICH.

Conclusion: PED demonstrates high long-term occlusion and low complication rates, suggesting it is a safe and effective treatment option for saccular aneurysms. Additionally, newer devices exhibit reduced thrombogenic profiles and safety with decreasing trends in ICH, ischemic stroke, and delayed aneurysmal rupture.