The US Food and Drug Administration (FDA) approved the first carotid stenting system in 2004, and since then the use of the procedure has steadily increased in America.  However, carotid stenting is a technically demanding procedure, and several studies have noted a significant learning curve for operators performing the procedure.  This study investigated the experience base of those currently performing carotid stenting in the US by examining annual volume and experience, and their relationship to outcomes, amongst new operators.

The authors obtained data on patients undergoing carotid stenting between January 2005 and December 2007. However, the study cohort was restricted to those patients who underwent carotid stenting by new operators who first performed carotid stenting after Match 17, 2005; authors performing carotid stenting prior to this were considered ‘experienced’.  The primary outcome was 30-day mortality following the procedure, stratified according to the operators’ annual volumes, and whether the procedure was performed early (1st-11th) or late (12th procedure onwards) during a new operator’s experience.  The secondary outcome was failure to receive an embolic protection device during the procedure.

Overall, 24 701 procedures were performed by 2339 operators. Of these, 11 846 were performed by 1792 new operators who first performed carotid stenting after March 17, 2005.  Observed 30-day mortality was higher among patients treated by operators with lower annual volumes (2.5% for those in the lowest quartile, vs 1.4% for those in the highest quartile; P<0.001), and among patients treated early (2.3%) vs late (1.4%) in the operator’s experience (P<0.001).  A higher risk of 30-day mortality in patients treated early vs late during a new operator’s experience (adjusted odds ratio, 1.7; P<0.001) was also noted.

Conclusions:

In this cohort of older patients undergoing carotid stenting, increased mortality was seen when the procedure was performed by new operators, and those who did fewer procedures each year.

• Nallamothu BK, Gurm HS, Ting HH et al.  Operator Experience and Carotid Stenting Outcomes in Medicare Beneficiaries.  JAMA 2011;306:1338-1343.