颈动脉支架置入术后支架内新生内膜特征及其与支架内再狭窄的关系

OBJECTIVE: Details of in-stent neointima (ISN) that form within a stent after carotid artery stenting (CAS) remain unknown. We aimed to investigate the characteristics of ISN observed on follow-up ultrasonography (US) after CAS and examine its association with in-stent restenosis (ISR).

MATERIALS & METHODS: A total of 371 consecutive patients diagnosed with carotid artery stenosis who underwent CAS and were followed up for at least 18 months between 2008 and 2023 were included. US was conducted at 1, 3, 6, and 12 months after CAS and every 6 months thereafter. Factors associated with ISN formation and its timing were investigated. Additionally, the location of ISN development within the stent and its relationship with ISR were examined.

RESULTS: ISN was confirmed in 221 patients. Significant factors associated with ISN formation included use of closed-cell stents and higher postoperative stenosis rate. The median time for ISN detection was 3 months (mean 3.27 ± 2.09 months). The most common locations of ISN formation were the side with the highest plaque volume on the short axis and the stent's proximal edge on the long axis. There were 17 patients with ISR, and ISN thickness was an independent risk factor for ISR development (p = 0.047). The cutoff value of ISN thickness for detecting ISR was 0.80 mm.

CONCLUSIONS: ISN development is associated with procedural technique and exhibits both temporal and segment-specific characteristics. Additionally, patients with an ISN thickness ≥ 0.80 mm on carotid US after CAS require careful follow-up, considering their greater ISR risk.