Learning Curve for Transoral Endoscopic Thyroid Lobectomy

Objective. To define the learning curve for transoral endoscopic thyroidectomy via the vestibular approach (TOETVA). Study Design. Case series with planned data collection. Setting. Tertiary care academic hospital. Subjects and Methods. Included patients were those who met the 2015 American Thyroid Association guidelines for lobectomy and our group's previously documented indications for TOETVA. Operative time (incision to closure) was used as a surrogate for procedural proficiency and plotted as a function of case number to determine a learning curve. A simple moving average of operative time was then calculated, with the proficiency case defined as the case number where the slope of this curve changed. Demographic/characteristic data, outcomes, and complications were compared between the skill acquisition period (case 1 to proficiency case) and the proficiency period (remaining cases). A linear regression model was then used to calculate and compare the slopes of the skill acquisition and proficiency periods in the "operative time versus case number'' plot. Results. Thirty cases were attempted, with a procedural success rate of 29 of 30 (94%) and no incidence of permanent mental nerve or recurrent laryngeal nerve injury. The proficiency case was case 11. There was a statistically significant difference between the skill acquisition and proficiency periods in slopes of the linear regressions (-16.7 vs -0.3, respectively; P < .001) and median operative times (191 vs 119 minutes, P < .001). There was no difference in demo-graphics, procedural success rate, or complication rate between the periods. Conclusions. The learning curve for TOETVA was 11 cases for the surgeon evaluated in this series.