Factors Associated with Major Re-Recanalization following Second Coiling for Recanalized Aneurysms: A Multicenter Experience over 20 Years during Long-Term Follow-up

BACKGROUND AND PURPOSE: Second coiling for recanalized aneurysms can mitigate the risk of delayed rupture, though re-recanalization may still occur. However, factors associated with re-recanalization after second coiling for recanalized aneurysms have yet to be adequately investigated. The present study explored a large, multicenter data set accumulated over 20 years to identify factors associated with major re-recanalization after second coiling for recanalized aneurysms. MATERIALS AND METHODS: We retrospectively reviewed 188 consecutive aneurysms in 185 patients who underwent second coiling for saccular recanalized aneurysms at 3 institutions from January 2003 to December 2023. Patients were classified into 2 groups: with major re-recanalization (R group) and without major re-recanalization (NR group). To identify factors associated with major re-recanalization, clinical, anatomic, and procedural characteristics were compared between the 2 groups by multivariate logistic regression analysis and stepwise selection. RESULTS: During follow-up (mean, 62.3 ± 51.2 months), 72 (38.3%) of the 188 recanalized aneurysms showed major re-recanalization. In univariate analysis, compared with the NR group, the R group showed significantly larger aneurysm size, neck size, and aneurysm volume at first coiling and lower rates of stent-assisted coiling, use of an intermediate catheter (IMC), and complete occlusion at second coiling. Stepwise multivariate logistic regression analysis revealed neck size at first coiling (OR 1.18; 95% CI: 1.04-1.33) as an independent risk factor and stent-assisted coiling (OR 0.34; 95% CI: 0.15-0.79), use of an IMC (OR 0.35; 95% CI: 0.16-0.80), and complete occlusion at second coiling (OR 0.16; 95% CI: 0.033-0.70) as independent protective factors for major re-recanalization. CONCLUSIONS: The main risk factor for major re-recanalization after second coiling of recanalized aneurysms was neck size at first coiling, and protective factors included stent-assisted coiling, use of an IMC, and complete occlusion at second coiling. Second coiling for recanalized aneurysms may reduce the risk of major re-recanalization by using a stent or IMC and achieving complete occlusion.