Abstract WP85: Risk factors for Stenosis of Stents Utilized for Stent Assisted Coiling of Unruptured Intracranial Aneurysms

Introduction: Stent-assisted coil embolization facilitates the treatment of wide-necked aneurysms. In-stent stenosis, although rare, may lead to stroke by occlusion of the parent artery or by thromboembolism. To our knowledge, the risk factors for in-stent stenosis in this context have not yet been investigated. Hypothesis: We hypothesized that cardiovascular risk factors and vessel size would be associated with in-stent stenosis. Methods: Consecutive patients undergoing stent-assisted coil embolization at our institution using the Neuroform stent (Stryker, Kalamazoo, MI, USA) were identified by billing records. Medical comorbidities were extracted retrospectively from patient charts. In-stent stenosis on last angiogram and vessel size (dichotomized into Results: A total of 224 unruptured aneurysms were treated with stent assisted-coil embolization between 2003 and 2010 utilizing the Neuroform stent. Follow-up catheter angiography was available in 196/224 (87.5%) at mean of 19 mos in those with in-stent stenosis and 24 mos in those without. In-stent stenosis occurred in 8/196 (4.1%). Mean age was 59 in those with in-stent stenosis and 62 in those without. The prevalence of cardiovascular risk factors in the groups with and without stenosis were as follows: diabetes 25% (2/8) vs. 6.9% (13/188), hypertension 42.6% (80/188) vs. 50% (4/8), hyperlipidemia 13% (1/8) vs. 5.9% (11/188), coronary artery disease 13% (1/8) vs. 3.7% (7), and smoking 38% (3/8) vs. 39% (75/188). Vessel size was Conclusions: The overall risk of in-stent stenosis in patients undergoing stent-assisted coil embolization was relatively low. Although cardiovascular comorbidities were numerically more common in patients with in-stent stenosis, the differences between the two groups were not statistically significant.