Carotid artery stenting with neuroprotection: assessing the learning curve and treatment outcome

PURPOSE: Carotid artery stenting (CAS) has emerged as an acceptable treatment alternative in high-risk patients with carotid stenosis. The purpose of this study was to assess the effect of the learning curve on treatment complications and the clinical outcomes of CAS. METHODS: Clinical variables and treatment outcomes of 200 consecutive CAS procedures in 182 patients (mean age 72 years) with carotid stenosis > or = 70% during a 40-month period were analyzed. Four sequential groups (groups I, II, III, and IV) of 50 consecutive interventions were compared with regard to technical success, periprocedural complications, and treatment outcomes. RESULTS: Treatment indications and relevant risk factors were similar among the 4 groups. The overall technical success and combined 30-day stroke and death rates were 98% and 2.5%, respectively. An increase in the technical success rate was noted in the latter 3 groups compared with group I (P < .05). Total procedural time and contrast volume were significantly higher in group I compared with the latter 3 groups (P < .05). The intraoperative anticoagulation regimen was changed from intravenous heparin combination to bivalirudin after the first 54 patients, which resulted in decreased bleeding complications in groups III and IV (P = 0.03) compared with the first group. The 30-day stroke and death rate in groups I and II were 8% and 2%, respectively, and was decreased significantly in groups III and IV (0% and 0%, respectively, P < .05). A Cox regression model identified procedural volume (P = .03) as a predictor of decreased complication rate. CONCLUSIONS: CAS with neuroprotection can provide excellent treatment outcomes. Our experience demonstrates a procedure-associated learning curve as evidenced by decreased procedure-related complications, fluoroscopic time, and contrast volume occurring with increased physician experience. Procedural success was also enhanced partly by endovascular device refinement and an improved anticoagulation regimen. Successful CAS outcomes can be achieved once physicians overcome the initial procedure-related learning curve.