Postoperative Time-of-Flight Magnetic Resonance Angiography Classification is a Predictor of Postoperative Recanalization of Unruptured Cerebral Aneurysms

Background: Endovascular treatment has become the preferred approach for managing unruptured cerebral aneurysms, with simple and balloon-assisted coil embolization as the standard first-line therapy. However, recanalization after coil embolization remains a major clinical concern. This study aimed to evaluate the predictive factors for recanalization using time-of-flight magnetic resonance (TOF-MR) angiography.

Methods: This retrospective multicenter study analyzed data from 241 patients with unruptured cerebral aneurysms who underwent coil embolization at 5 stroke centers. Aneurysms were evaluated using TOF-MR angiography within 7 days postprocedure and at follow-up. The study investigated the role of aneurysm characteristics and the Postoperative TOF-MR Angiography (PTMA) classification in predicting recanalization.

Results: Of the 241 aneurysms analyzed, 79 (32.7%) exhibited recanalization, and 15 (6.2%) required retreatment. Aneurysms with a maximum diameter of ≥10 mm were associated with a higher risk of recanalization (odds ratio, 3.27; 95% confidence interval (CI), 1.38-7.75; P < 0.01). The PTMA classification, which indicated incomplete occlusion (small residual neck/residual neck/partial occlusion), also showed a significant association with recanalization (odds ratio, 4.82; 95% confidence interval, 2.17-10.7; P < 0.01). The modified Raymond-Roy classification (Class IIIb) also contributed to the prediction of recanalization (odds ratio, 3.09; 95% confidence interval, 1.50-6.38; P < 0.01).

Conclusions: Aneurysm size, the modified Raymond-Roy classification, and PTMA classification within 7 days of coil embolization were significant predictors of recanalization. This study suggests that TOF-MR angiography may be accurate, and that PTMA classification may serve as an appropriate predictor of aneurysm recanalization. Further prospective studies with larger cohorts are required to validate our findings.