Abstract 144: Carotid Artery Stenting in Patients with Radiation‐Induced Carotid Artery Stenosis: Safety Profile and Long‐Term Outcome with a Focus on the Frequency of In‐Stent Restenosis

Background Radiation‐induced carotid artery stenosis (RICS) is a known adverse effect of radiotherapy (RT) and is associated with a risk of ischemic stroke. Carotid endarterectomy (CEA) is considered to carry a higher risk in irradiated vessels, making carotid artery stenting (CAS) an increasingly favorable option. While previous studies have reported on the outcomes of CAS procedures for RICS lesions, our study provides new insights by focusing on long‐term outcomes of CAS, particularly the incidence of in‐stent restenosis (ISRS) in this patient subgroup. Methods This monocentric retrospective analysis included 45 patients with 65 RICS (asymptomatic stenosis, n = 41; symptomatic stenosis, n = 24; male, n = 40; median age, 66 years; mean degree of stenosis, 78.2%, multifocal stenoses with CCA involvement, n=17 (37.8%)) who underwent CAS between 2009 and 2022. Patients’ characteristics, peri‐ and postprocedural neurological events, and follow‐up data were evaluated. Results CAS was successfully performed in all cases. No major or minor ischemic strokes occurred. An asymptomatic subarachnoid hemorrhage was detected in one patient and was potentially associated with cerebral hyperperfusion syndrome. Two (3.1%) in‐stent thrombosis occurred. ISRS >50% was diagnosed in 12 (18.5%) treated vessels within a mean of 17.9 months (7‐49 months) and re‐intervention was performed in all cases. 5 of the 12 re‐treated vessels showed ISRS recurrence >50% without neurological events. In more than 13 years of long‐term follow‐up, recurrent ischemic strokes occurred in two (4.4%) patients. Conclusion In our experience, CAS demonstrated a favorable safety and efficacy profile in patients with RICS, offering the added advantage of effectively addressing specific stenosis patterns, such as long‐segment or multifocal stenoses. However, the incidence of ISRS appears to be higher in this specific patient subgroup, thus underscoring the importance of rigorous follow‐up examinations.