The CUSUM analysis of the learning curve for endoscopic thyroidectomy by the breast approach

To evaluate the learning curve for endoscopic thyroidectomy by the breast approach (ETBBA) based on the cumulative summation (CUSUM) technique.

The study included 110 consecutive patients who underwent ETBBA by a single surgeon between January 2009 and May 2012 at the Xiangya Hospital of Central South University, Changsha, China. The learning curve was evaluated using the CUSUM technique. The patients were chronologically arranged into 3 phases by the CUSUM analysis for operative time. Demographic data and operative parameters were also analyzed.

The mean operative time (OT) was 125.3 minutes. The conversion rate for technical difficulties and the definitive complication rate were 6.4% and 10%, respectively. The learning curve was analyzed mainly by OT using the CUSUM technique. There was a significant improvement in the average OT (P < .05) after the first 27 patients and again after the first 67 patients (P < .05). A downward trend in OT was found up to the last patient. There were similarities in gender, tumor size, extent of surgery, blood loss, histology, hospital stay, conversion rate, and complications among the 3 phases. Comparison of 2 neighboring phases also showed no significant differences in age.

ETBBA performed by surgeons has a remarkable learning curve. There were 27 cases in the early stage of the learning curve, whereas mastery level could be achieved with 67 cases.