In-stent stenosis after stent-assisted coiling: incidence, predictors and clinical outcomes of 435 cases

Neuroform and Enterprise are widely used self-expanding stents designed to treat wide-necked intracranial aneurysms. To assess the incidence, clinical significance, predictors, and outcomes of in-stent stenosis (ISS). Angiographic studies and hospital records were retrospectively reviewed for 435 patients treated between 2005 and 2011 in our institution. A multivariable regression analysis was conducted to determine the predictors of ISS. The Neuroform stent was used in 264 patients (60.7%) and the Enterprise in 171 patients (39.3%). A total of 11 patients (2.5%) demonstrated some degree of ISS during the follow-up period at a mean time point of 4.2 months (range, 2-12 months). The stenosis was mild ( 75%) in 1 patient (0.2%). No patients were symptomatic or required further intervention. There was complete ISS resolution in 2 patients, partial resolution in 2 patients, and no change in 5 patients on follow-up angiography. Patients developing ISS were significantly younger than those without ISS (40.3 vs. 54.9 years; P