Impact of residual stenosis on clinical outcomes when performing carotid artery stenting without postdilation.

Abstract

Many centers consider postdilation if the final angiography after carotid artery stenting (CAS) shows residual stenosis of >30% to 40%. Postdilation has been demonstrated to potentially increase the risk of developing neurologic events. This study aimed to investigate the safety of CAS without postdilation regardless of the degree of residual stenosis. We retrospectively investigated 191 patients who underwent transfemoral CAS without postdilation intendedly. All cases underwent mild predilation and self-expanding stent implantation. We divided the patients into a residual stenosis of ≥40% group (n= 69 [36.1%]) and a residual stenosis of<40% group (n= 122 [63.9%]) according to their final angiography. We compared the procedural (within 30days after CAS) and nonprocedural (afterward) adverse cardiovascular events and in-stent restenosis between the two groups. We also investigated the incidence of perioperative hemodynamic depression between the groups and the changes in residual stenosis over the follow-up time. Patients in the residual stenosis of ≥40% group had a higher preoperative stenosis rate and a greater proportion of severely calcified lesions than those in the<40% group. There was one procedural cardiac death (0.5%), five strokes (2.6%), and four myocardial infarctions (2.1%). A total of 2.9% had stroke or death procedurally in the residual stenosis of ≥40% group and 3.2% in the residual stenosis of<40% group (P> .950). The median nonprocedural follow-up time was 22months, with a total of six deaths and four strokes. The cumulative 2-year death or stroke rate was 6.2%, with 5.9% in the residual stenosis of ≥40% group versus 6.7% in the residual stenosis of<40% group (P= .507). There were two cases of in-stent restenosis in the residual stenosis of ≥40% group and three in the residual stenosis of<40% group (P= .927). The difference in the peak systolic velocity of the target lesion between groups at 3months after CAS was no longer present, and residual stenosis stabilized at 10% to 20% at 6months in both groups. The patients showed an association between increasing hemodynamic depression incidence and residual stenosis in a significantly graded response (P=.021). Residual stenosis after carotid stenting without postdilation is not associated with a risk of postoperative adverse events. This study provides evidence for the feasibility of a no postdilation strategy for CAS.