Experience matters more than specialty for carotid stenting outcomes

Objective: The introduction of carotid stenting has led to a rapid rise in the number of vascular specialists performing this procedure. The Carotid Revascularization Endarterectomy vs Stenting Trial (CREST) has shown that carotid stenting can be performed with an equivalent major event rate compared with carotid endarterectomy. However, there is still controversy about the appropriate training and experience required to safely perform this procedure. This observational study examined the performance of carotid stenting with regard to specialty and case volume. Methods: From 2004 to 2011, inpatients diagnosed with carotid stenosis who had a carotid stenting procedure were extracted from the Nationwide Inpatient Sample database. The cohort was separated on the basis of the provider performing the procedure (surgeon vs interventionalist), hospital location, and volume. Surgeons were defined as providers who also performed either a carotid endarterectomy or femoral-popliteal bypass during the same time interval. Primary end points analyzed included stroke, myocardial infarction, and 30-day mortality. Length of stay and hospital costs were also analyzed as secondary outcomes. Results: A total of 20,663 cases of carotid stenting were found; 15,305 (74%) cases were identified to be performed by a "surgeon," whereas 5358 (26%) were done by an "interventionalist." The majority of cases were done at hospitals in urban locations (96.51%) and designated teaching institutions (61.47%). Unadjusted outcomes were similar between surgeons and interventionalists in terms of stroke (4.33% and 4.41%), myocardial infarction (2.10% and 2.13%), and mortality (0.84% and 1.03%) respectively. Qualitatively, volume per 10 cases was shown to decrease the risk of stroke. Adjusted multivariate analysis demonstrated no statistical significance between primary end point outcomes. However, length of stay (2.81 vs 3.08 days) and total charges ($48,087.61 and $51,718.77) were lower for procedures performed by surgeons. Conclusions: Surgeons are performing the majority of carotid stent procedures in the United States. The volume of cases performed by a provider, rather than the provider's specialty, appears to be a stronger predictor of adverse outcomes for carotid stenting. There were, however, significant cost differences between surgeons and interventionalists, which needs to be further evaluated at an institutional level.