Learning curve for endoscopic tympanoplasty: Initial experience of 221 procedures.

Background: The learning curve for endoscopic tympanoplasty has never been quantitatively reported. The present study depicted the learning curve for endoscopic tympanoplasty and evaluated how many procedures an otologist requires to attain proficiency in this technique.
Methods: We reviewed the medical charts of consecutive patients who underwent endoscopic tympanoplasty between January 1, 2013 and June 1, 2015. We enrolled patients with simple perforations of the tympanic membrane and excluded those with ossicular chain disease. The main outcome was learning curves for endoscopic tympanoplasty, which illustrated changes in the mean operative time and graft success rate according to the patient numbers. We subsequently estimated and verified the threshold value using statistical methods.
Results: A total of 221 procedures were included. For the learning curve of the mean operative time, the time gradually decreased from 75 minutes to 55 minutes. After the 150 ^th patient, the mean operative time stabilized to < 60 minutes. For the learning curve of the graft success rate, the rate sharply increased from 75% to 95%. After the 50 ^th patient, the graft success rate reached a plateau and fluctuated between 85% and 100%. We subsequently verified that the 50 ^th and 150 ^th patients were appropriate threshold values. Moreover, the graft success rate of perforations < 50% was significantly higher than that of perforations > 50%.
Conclusion: These curves illustrate significant progress of the surgeon during the first 50 patients, considering the graft success rate, reaching an advanced level after the 150 ^th patient, considering the mean operating time.
(Copyright © 2017. Published by Elsevier Taiwan LLC.)