Introduction: Posterior communicating artery (PComA) segment aneurysms are one of the most frequently encountered intracranial aneurysms. Currently, there is limited literature describing the use of pipeline embolization device (PED) in PComA aneurysms and the relationship of radiological features with aneurysm occlusion and other outcomes. The aim of this study is to assess the efficacy and safety of PED in the treatment of saccular PComA aneurysms. We also assessed the impact of anatomical variations that may influence both angiographic and clinical outcomes, including the presence of a fetal PComA, the relationship of the origin of PComA to the aneurysm, and the subsequent patency of the of the PComA following PED placement.

Methods: A multicenter retrospective review of 3 prospectively collected between January 2013 and December 2017 patients treated with pipeline embolization devices (PED).

Results: We identified 57 patients for this cohort with 60 saccular aneurysms; Mean age was 60.5 years, and 49 (86.0%) patients were female. A total of 55 (91.7%) aneurysms were unruptured. Median imaging last follow-up was 8.5 months. Complete occlusion at last imaging follow-up occurred in 84.0% of aneurysms. Good functional outcome at last follow-up (mRS 0-2) was achieved in 94.4% of patients. PComA patency rate on last follow-up was 77.1%, and for those who occluded, all were asymptomatic. Presence of fetal PComA, type of PComA origin and patency of PComA on follow-up were not found to have significant impact on aneurysm occlusion (p=0.61, p=0.40, and p=0.14, respectively).

Conclusions: PED treatment of PComA aneurysms results in acceptable occlusion rates. This study did not find that the presence of fetal PComA, type of PComA origin and patency of PComA on follow-up to have an impact on PComA segment aneurysm occlusion.

Patient Care: Treatment of PComA segment aneurysms with flow diverter is safe and effective. The presence of an artery originating from the aneurysm and a fetal variant PComA should not discourage flow diverter treatment in such cases.

Learning Objectives: 1. Flow diverter treatment of posterior communicating artery (PComA) segment aneurysms results in acceptable occlusion rates with adequate safety. 2. Presence of fetal PComA, type of PComA origin and patency of PComA on follow-up do not have an impact on PComA segment aneurysm occlusion after flow diverter treatment. 3.

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