Background: We sought to determine the incidence of restenosis following carotid endarterectomy (CEA) and carotid angioplasty with stenting (CAS), analyze temporal trends to identify an optimal follow-up schedule, and identify covariates associated with restenosis.
Methods: Patients undergoing CEA or CAS at our institution between 2009 and 2016 were assessed retrospectively. Temporal trends in peak systolic velocity (PSV) were examined qualitatively. Restenosis was defined as an increase in PSV to >250 cm/s, or as >70% stenosis on CTA or catheter angiography. Rates of restenosis were calculated using the Kaplan-Meier method. Cox proportional hazards regression was used to evaluate for an association between selected covariates and time to restenosis.
Results: We analyzed 204 CEA and 113 CAS cases, of which 85% had symptomatic disease. Cumulative restenosis rates were 9% at one year and 14% at four years (Figure 1). There was no difference between CEA and CAS procedures (hazard ratio 1.285, p=0.58). Interestingly, there was a trend toward higher risk of restenosis for left-sided procedures, which did not reach statistical significance (hazard ratio 2.401, p=.051). Restenosis was asymptomatic in 96% of occurrences. Univariate regression identified no covariates associated with restenosis at a threshold of p<0.05 .
Conclusions: The restenosis rate was overall low after CEA and CAS, with the highest risk seen in the first year, and significantly reduced later on. Most restenoses were asymptomatic. We did not identify specific covariates associated with restenosis. Close follow-up with imaging is recommended during the first year after treatment. Due to relatively low incidence of delayed stenosis, follow-up beyond 1 year should be tailored based on individual risk factors.