Predictors of in-stent stenosis and occlusion after endovascular treatment of intracranial vascular disease with the Willis covered stent

Covered stent placement has emerged as a promising therapeutic option for intracranial vascular lesions. However, in-stent stenosis and occlusion continue to be important concerns with the use of a covered stent, which is more thrombogenic than other types of stents. The purpose of this study was to determine predictors of in-stent stenosis and occlusion for covered stents used in the treatment of intracranial vascular diseases. Clinical, procedural and angiographic data of 46 patients with 49 intracranial vascular lesions treated with the Willis covered stent (Micro-Port, Shanghai, China) between April 2005 and October 2010 were collected and analyzed retrospectively. Univariate analysis and multivariate logistic regression analysis were performed to determine the factors predictive of in-stent stenosis and/or occlusion of the stents. In-stent stenosis and/or occlusion were documented at angiography in six patients with six lesions, and no stenoses or occlusions were seen at angiography in the remaining 40 patients with 43 lesions. Univariate analysis revealed that hypertension, post-procedure irregular antiplatelet therapy and cerebrovascular arteriosclerosis were associated with in-stent stenosis and/or occlusion. By multivariate logistic regression analysis, post-procedure irregular antiplatelet therapy (odds ratio [OR] = 15; 95% confidence interval [CI], 1.172-192.004; p = 0.037) and cerebrovascular arteriosclerosis (OR = 19; 95% CI, 1.374-262.659; p = 0.028) were independent predictors of in-stent stenosis and/or occlusion. Thus, post-procedure irregular antiplatelet therapy and coexistent cerebrovascular arteriosclerosis appear to increase the risk of in-stent stenosis and/or occlusion of covered stents in the treatment of intracranial vascular disease.