Comparison of open- and closed-cell stent design outcomes after carotid artery stenting in the Vascular Quality Initiative

Background: The association between stent design and outcomes after carotid artery stenting (CAS) has remained controversial. The available data are conflicting regarding the superiority of any specific stent design. The present study investigated the association between cell design and outcomes after carotid artery stenting (CAS) in a real world setting. Methods: Patients who had undergone CAS with distal embolic protection in the Society for Vascular Surgery Vascular Quality Initiative (VQI) database from 2016 to 2018 were included in the present study. Patients undergoing CAS for trauma or dissection or more than two treated lesions were excluded. We also excluded lesions for which more than two carotid stents had been used and lesions confined to the common or external carotid artery. Univariable and multivariable logistic regression analyses were used to compare the outcomes after CAS between the open- and closed-cell stent designs. Results: Of the 2671 CAS procedures included in the present analysis, 1384 (51.8%) had used closed-cell stents and 1287 (48.2%) had used open-cell stents. On univariable analysis, no significant differences were noted between the closed- and open-cell stents in in-hospital mortality (1.8% vs 1.4%; P = .40), stroke (1.8% vs 2.4%; P = .28), and stroke/death (3.3% vs 3.5%; P = .81). After adjusting for potential confounders (ie, age, symptomatic status, previous major amputation, statin and antiplatelet use, American Society of Anesthesiologists class, elective procedures, approach, and post-stent dilatation), no difference was noted in in-hospital stroke/death between the two stent designs (odds ratio [OR], 1.08; 95% confidence interval [CI], 0.68-1.74; P = .74). However, the interaction between stent design (open vs closed) and lesion location (bifurcation vs internal carotid artery [ICA]) was statistically significant (P = .02). Closed-cell stents were associated with five times the odds of in-hospital stroke/death when used in carotid artery bifurcation (OR, 5.5; 95% CI, 1.3-22.2; P = .02). However, when the stent was limited to the ICA, no differences were noted (OR, 0.87; 95% CI, 0.51-1.45; P = .62). One-year follow-up data were available for 19% of patients. No differences in ipsilateral stroke or death at 1 year were noted between the open- and closed-cell stents, except when the lesion was located in the carotid bifurcation (hazard ratio, 6.7; 95% CI, 1.4-31.4; P = .02). Conclusions: Closed-cell stents were associated with an increased odds of in-hospital stroke/death for carotid bifurcation lesions, which might be related to the relatively lower conformability of closed-cell stents in the tortuous and diameter-mismatched bifurcation anatomy vs the relatively linear uniform diameter of the ICA. Improved follow-up and in-depth analysis of lesion-specific characteristics that might influence the outcomes of these two designs are needed to validate these results.