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

Abstract

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 ± 7.9months). 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 6months, 15 (34.9%) within 18months and 2 (4.6%) within 30months. Cumulative survival rates without recanalization were significantly lower in subjects with aneurysms >7mm (p = 0.014), with bifurcation aneurysms (p = 0.009) and with subarachnoid haemorrhage (SAH) at presentation (p < 0.001). Multivariate analysis indicated that aneurysms >7mm (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 6months post-procedure were stable in long-term monitoring. However, aneurysms >7mm and bifurcation aneurysms were predisposed to late recanalization. • Most coiled aneurysms showing complete occlusion at 6months 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 7mm and bifurcation aneurysms were predisposed to late recanalization.