Risk factors for recurrence after coil embolization for internal carotid artery-posterior communicating artery aneurysms

Background: Use of coil embolization for internal carotid artery-posterior communicating artery aneurysms (IC-PC ANs) has been increasing. However, the recurrence rate after embolization is rather high compared to that after surgery. The aim of this study was to evaluate the factors related to recurrence after coil embolization for IC-PC ANs. Methods: A total of 69 patients with IC-PC ANs treated with coil embolization between 2013 and 2019 were retrospectively enrolled, and we evaluated whether the aneurysms recurred after embolization. The patients were divided into two groups (no-recurrence group and recurrence group), and the relationships of several patient or aneurysm characteristics and treatment-related information with aneurysm recurrence were examined. Results: Twenty patients (29%) developed aneurysm recurrence. There were significant differences in dome size (5.19 mm/6.48 mm, p = 0.01), neck width (3.25 mm/4.23 mm p = 0.009), aneurysm volume (47.5 mm3/120 mm3, p = 0.003), and Pcom diameter (1.11 mm/1.96 mm p = 0.005) between the two groups. Pcom diameter was the independent risk factor for recurrence (odds ratio: 3.52, 95%CI 1.43–8.69, p = 0.006). The cutoff for Pcom diameter as the factor related to recurrence was 1.79 mm, with sensitivity of 60% and specificity of 83.7%. Conclusion: In this study, dome size, neck width, aneurysm volume, and Pcom diameter were associated with recurrence after coil embolization for IC-PC ANs. In particular, Pcom diameter could be an independent risk factor for recurrence.