Occlusion of Fetal Posterior Circulation Aneurysms Treated with Pipeline Embolization

Introduction: The fetal posterior communicating artery (PComA), defined as an atretic P1 segment with carotid circulation feeding of the posterior cerebral artery, is a variation of the posterior circle of Willis circulation. Aneurysms arising from this variant are challenging to treat. Across the literature, flow diversion of fetal PComA aneurysms has shown lower rates of occlusion when compared with patients without this variant. Therefore, this study aimed to clarify the efficacy of using the Pipeline Embolization Device (PED) to treat fetal PComA aneurysms and to identify factors predicting obliteration of these aneurysms.

Methods: A retrospective analysis was performed on fetal PComA aneurysms treated with PED from 2013 to 2023. Aneurysms with PED placed across the fetal PComA were selected for analysis. Data was collected on patient demographics, aneurysm characteristics, intervention specifics, and outcomes. Aneurysm occlusion was assessed during angiographic follow-up. Univariate statistical analysis was performed to compare aneurysms achieving satisfactory occlusion.

Results: Among 211 patient treated for PComA aneurysms, 39 patients (33 female, 6 male) with a mean age of 56.2 ± 15.3 years had a fetal PComA. Flow diversion with PED achieved complete occlusion in 26 cases (67%). Two patients (5%) experienced thromboembolic complications at follow-up. No hemorrhagic complications were reported, and no retreatment was required. There was no significant difference in mean width, depth, volume, aneurysm diameter, or parent artery diameter in occluded vs. non-occluded aneurysms. However, patients with occluded fetal PComA aneurysms had a significantly lower mean age than those with non-occluded aneurysms (56.2 years vs 69.7 years; p< 0.001).

Conclusion : PED treatment for 39 fetal PComA aneurysms demonstrates a complete occlusion rate of 67%, which is higher than previously reported studies. This rate from a larger patient population and the lack of recurrence during follow-up highlight PED as a potentially safe and effective intervention for treating these complex aneurysms.