Risk Factor Analysis of Recanalization Timing in Coiled Aneurysms: Early versus Late Recanalization.

BACKGROUND AND PURPOSE

Long-term documentation of anatomic and angiographic characteristics pertaining to the timing of recanalization in coiled aneurysms has been insufficient. Our intent was to analyze and compare early and late-phase recanalization after coiling, identifying respective risk factors.

MATERIALS AND METHODS

A total of 870 coiled saccular aneurysms were monitored for extended periods (mean, 30.8 ± 8.3 months). Medical records and radiologic data were also reviewed, stratifying patients as either early ( = 128) or late ( = 52) recanalization or as complete occlusion ( = 690). Early recanalization was equated with confirmed recanalization within 6 months after the procedure, whereas late recanalization was defined as verifiable recanalization after imaging confirmation of complete occlusion at 6 months. A multinomial regression model served to assess potential risk factors, the reference point being early recanalization.

RESULTS

Posterior circulation ( = .009), subarachnoid hemorrhage at presentation ( = .011), second attempt for recanalized aneurysm ( < .001), and aneurysm size >7 mm ( < .001) emerged as variables significantly linked with early recanalization (versus complete occlusion). Late (versus early) recanalization corresponded with aneurysms ≤7 mm ( = .013), and in a separate subanalysis of lesions ≤7 mm, aneurysms 4-7 mm showed a significant predilection for late recanalization ( = .008). However, the propensity for complete occlusion in smaller lesions (≤7 mm) increased as the size diminished.

CONCLUSIONS

Although long-term complete occlusion after coiling was more likely in aneurysms ≤7 mm, such lesions were more prone to late (versus early) recanalization, particularly those of 4-7 mm in size. Long-term follow-up imaging is thus appropriate in aneurysms >4 mm to detect late recanalization of those formerly demonstrating complete occlusion.