Mid-term risk factor analysis and predictors of restenosis in patients undergoing carotid artery stenting

This study investigated the timing and risk factors of restenosis (≥50% stenosis) in patients undergoing carotid artery stenting (CAS).

This retrospective case series included patients who underwent CAS between January 2007 and December 2022 at a tertiary referral vascular centre in Hong Kong. Patient demographics, co-morbidities, operative details, and clinical and radiological surveillance findings were reviewed. Univariate and multivariable Cox regression analyses were performed.

In total, 120 CAS procedures (13 bilateral) were performed in 102 patients. Overall, 80% of patients were male (mean age: 66.9 years), and 45 (37.5%) were symptomatic preoperatively. The mean follow-up duration was 6.7 ± 4.2 years. Post-procedure, ipsilateral stroke occurred in 10 (8.3%) cases; the stroke-related mortality rate was 2.5%. In all, 51 (46.4%) of 110 evaluable cases developed restenosis, of which 29 (26.3%) occurred within 1 year postoperatively. The mean time to ≥50% restenosis development was 94.9 months. Univariate Cox regression analysis showed that a history of nasopharyngeal carcinoma (hazard ratio [HR]=2.12; P=0.01) and previous neck radiotherapy (HR=2.96; P<0.001) were significantly associated with higher restenosis risk. A greater number of stents, longer stent length, and post-dilation balloon diameter >5.5 mm (all P<0.001) were linked to higher restenosis risk. In multivariable Cox regression analysis, a history of radiotherapy (HR=3.72; P=0.01) and larger post-dilation balloon diameter (HR=2.10; P=0.01) remained associated with higher restenosis risk.

The 12-month restenosis rate was 26.3%, although restenosis rarely caused new neurological events. A history of radiotherapy and larger post-dilation balloon diameter were associated with higher restenosis risk.