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Extended monitoring of coiled aneurysms completely occluded at 6-month follow-up: late recanalization rate and related risk factors



To estimate long-term durability in coiled aneurysms completely occluded at 6-month follow-up imaging, focusing on late recanalization rate and the risk factors involved.


A cohort of 620 patients harbouring 698 completely occluded coiled aneurysms at 6-month follow-up was subjected to extended monitoring (mean, 24.5 ± 7.9 months). Cumulative recanalization rate and related risk factors were analysed using Cox proportional hazards regression and Kaplan–Meier product-limit estimator.


Forty-three aneurysms (6.2 %) occluded completely at 6-months displayed recanalization (3.02 % per aneurysm-year) during continued surveillance (1425.5 aneurysm-years), with 26 (60.5 %) surfacing in another 6 months, 15 (34.9 %) within 18 months and 2 (4.6 %) within 30 months. Cumulative survival rates without recanalization were significantly lower in subjects with aneurysms >7 mm (p = 0.014), with bifurcation aneurysms (p = 0.009) and with subarachnoid haemorrhage (SAH) at presentation (p < 0.001). Multivariate analysis indicated that aneurysms >7 mm (HR = 2.37, p = 0.02) and bifurcation aneurysms (HR = 2.70, p = 0.03) were significant factors in late recanalization, whereas a link with SAH at presentation was marginal (HR = 1.92, p = 0.06) and stent placement fell short of statistical significance (HR = 0.47; p = 0.12).


Most (93.8 %) coiled aneurysms showing complete occlusion at 6 months post-procedure were stable in long-term monitoring. However, aneurysms >7 mm and bifurcation aneurysms were predisposed to late recanalization.

Key Points

Most coiled aneurysms showing complete occlusion at 6 months were stable.

Forty-three aneurysms (6.2 %) occluded completely at 6-month follow-up displayed late recanalization.

Late recanalization rate was 3.02 % per aneurysm-year during follow-up of 1425.5 aneurysm-years.

Aneurysms over 7 mm and bifurcation aneurysms were predisposed to late recanalization.

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coronary artery disease


diabetes mellitus


digital subtraction angiography




time-of-flight magnetic resonance angiography


unruptured intracranial aneurysms


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The scientific guarantor of this publication is Young Dae Cho. The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article. The authors state that this work has not received any funding. Sung-Eun Kim kindly provided statistical advice for this manuscript. Institutional review board approval was obtained. Written informed consent was waived by the institutional review board. Methodology: retrospective, case-control study, performed at one institution.

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Jeon, J.P., Cho, Y.D., Rhim, J.K. et al. Extended monitoring of coiled aneurysms completely occluded at 6-month follow-up: late recanalization rate and related risk factors. Eur Radiol 26, 3319–3326 (2016).

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  • Aneurysms
  • Stent
  • Recanalization
  • Occlusion
  • Coiling