Cerebral aneurysm neck diameter is an independent predictor of progressive occlusion after stent-assisted coiling

Abstract

Some intracranial aneurysms treated by stent-assisted coiling (SAC) with incomplete occlusion undergo progressive occlusion (PO) during follow-up period. We analyzed the predictors for the occurrence of PO. Among 74 cerebral aneurysms treated by SAC using the Enterprise or Neuroform stents from 2010 to 2015, we included 43 aneurysms with occlusion grade of neck remnant (NR, n=36) or residual aneurysm (RA, n=7) at the post-procedure. We defined PO as improvement in occlusion grade from RA to NR, or from NR or RA to complete occlusion on angiographic follow-up imaging at 6months after the procedure. We analyzed the independent predictors for PO using a multivariate logistic regression model and receiver operating characteristic (ROC) curve analysis. Forty-three aneurysms were analyzed, with mean volume embolization ratio of 30.3±6.7%. Twenty aneurysms (47%) achieved PO. Univariate analysis found that the median neck diameter of the aneurysms was smaller in aneurysms with PO than others. Multivariate logistic regression analysis also found that the odds ratio of neck diameter of the aneurysm for PO was 0.44 (95% CI, 0.19-0.82, p<0.01). Moreover, ROC curve analysis for PO found that the optimal cut-off value of the neck diameter was 5.5mm, with a sensitivity of 95%, specificity of 57% (p<0.01). Incompletely occluded aneurysms with a neck diameter of 5.5mm or less might be more likely to develop PO within 6months after SAC by using Enterprise or Neuroform stents.