Outcome of endovascular recanalization for intracranial in-stent restenosis.

Background and purpose In-stent restenosis (ISR) is one of the long-term adverse outcomes of endovascular angioplasty and stenting for symptomatic intracranial arterial stenosis. In this study, we try to evaluate the safety and efficacy of endovascular treatment for intracranial ISR. Methods We retrospectively collected patients with intracranial ISR who underwent endovascular treatment from June 2012 to August 2019 at a high-volume stroke center. Successful recanalization was defined as ≤30% residual stenosis. Stroke, myocardial infarction, and death after stenting within 30 days were used to evaluate periprocedural safety. Recurrent stroke in the territory of the culprit vessel and re-ISR in patients with clinical and vascular imaging follow-up data were used to evaluate the long-term outcome. Results 32 patients (59.6±7.2 years old) with ISR were recruited, including 22 patients (68.8%) treated with balloon dilatation, 8 patients (25%) with stenting, and 2 patients (6.3%) with failed procedures. Successful recanalization was achieved in 71.9% (23/32) of patients. There was no stroke, myocardial infarction or death within 30 days after the procedure. Recurrent stroke was found in 10.7% (3/28) of the patients, and re-ISR was found in 42.1% (8/19) of the patients. The re-ISR rate was lower in patients with stenting than in those with balloon dilatation (0% vs 57.1%, p=0.090), and in patients with successful recanalization than in those with unsuccessful recanalization (33.3% vs 75.0%, p=0.352), but with no statistically significant difference. Conclusions The periprocedural safety of endovascular treatment for intracranial ISR may be acceptable, but the long-term rates of recurrent stroke and re-ISR remain at high levels.