Pipeline Embolization Device (PED) for the Treatment of Intracranial Saccular Aneurysms: A Systematic Review and Meta-analysis of Long-term Outcomes

Introduction: Pipeline Embolization Device (PED) is commonly used to treat intracranial aneurysms. The indications of its use expanded significantly to the treatment of fusiform, blister, and dissecting intracranial aneurysms in the anterior and posterior circulation. The treatment of saccular aneurysms remains controversial due to the ample variety of management modalities, from endovascular to microsurgical. This study analyzes the long-term occlusion rate and complications in saccular aneurysms treated with PED.

Methods: We performed a systematic review and meta-analysis of studies, including a minimum of 10 patients treated with PED for saccular aneurysms with at least 1-year follow-up. The primary safety endpoints were the clinical complications: cumulative symptomatic stroke (confirmed clinically and radiographically), intracranial hemorrhage, and aneurysmal rupture. The primary efficacy endpoint was the complete aneurysm occlusion rate.

Results: Our analysis comprised 11 studies including 594 patients with 726 aneurysms. Most aneurysms were unruptured (72%, N=427) and small (77.4%). The mean age was 55.74 years, and most patients were women (78.3%; N= 465). One device was used in 580 aneurysms and coils were added in 21 aneurysms. Previously treated aneurysms were 5.8%. Most aneurysms were small (89.75%; N= 1,340 aneurysms). The long-term complete occlusion rate was 73% (95%, CI 62% to 82%, p< 0.01). The long-term symptomatic thromboembolic complication rate was 5% (95%, CI 2% to 8%, p=0.27). The rate of rupture rate was 4% (95%, CI 2% to 7%, p=0.48) and the rate of intracranial hemorrhage was 3% (95%,CI 1% to 5%, p=0.86)

Conclusion : The PED is a safe and effective method to treat intracranial saccular aneurysms: The long-term complete occlusion rate is high (73%), with almost a quarter of the patients persisting with residual filling. Even longer follow-ups are expected to show higher occlusion rates. The ischemic complication rate is 5 %, and hemorrhagic complications occur less than 3%.