Endoscopic tympanoplasty: learning curve for a surgeon already trained in microscopic tympanoplasty

The aim of this study was to evaluate the learning curve of endoscopic tympanoplasty for a surgeon already trained in microscopic tympanoplasty. We analyzed the clinical records of 81 patients who underwent transcanal endoscopic type 1 tympanoplasty and 30 control patients who underwent microscopic tympanoplasty between 2013 and 2015 in a tertiary hospital. All operations were performed by a single surgeon already trained in microscopic tympanoplasty. Patients were divided into four groups according to the date of surgery chronologically (group 1 early stage, group 2 intermediate stage, group 3 advanced stage and group 4 control). We evaluated the four groups according to surgery duration, audiometric results, and graft intake success. The operation duration shortened in accordance with the surgeon's experience and there were two subsequent steps during the learning curve: first, after 30 procedures; and second, after 60 procedures. The mean operation duration was 88.60 +/- 21.10 min in group 1, and 62.00 +/- 12.48 min in group 2. After 60 procedures, the mean operation duration was 43.81 +/- 8.34 min in group 3. In the control group, the microscopic tympanoplasty duration was 69.93 +/- 12.56 min. When we compared audiologic results (air conduction, bone conduction, and air bone gap) and graft intake success rates, there were no significant differences between groups. Endoscopic tympanoplasty is a minimally invasive and effective technique. Mastering endoscopic tympanoplasty takes approximately 60 operations for a surgeon already trained in microscopic tympanoplasty. Graft intake success rates and hearing results are stable during the learning curve.