Effect of training on the incidence of nerve damage in thyroid surgery

Background: In thyroid surgery early postoperative recurrent laryngeal nerve (RLN) dysfunction offers a sensitive measure of the quality of the operation. The aim of this study was to analyse the effect of training in thyroid surgery on the rate of early functional disturbances of the RLN after thyroid resection. Methods: In 617 patients (median age 48 years, female to male ratio 2.8 : 1) who underwent unilateral or bilateral thyroid resection, 1059 RLNs were subjected to operative risk. Laryngoscopy was performed before and after operation. The 45 surgeons were divided into three groups: group 1, specialist thyroid surgeons; group 2, experienced surgeons; and group 3, residents. Personal gain of experience was defined by the preceding number of thyroid operations. Within each group the complication profile was determined by adding the personal complication profiles of each surgeon. Results: The complication rates were low during surgical residency (group 3). In group 2 complication rates increased up to the 50th operation. Group 1 showed the expected exponential decrease to under 1 per cent after another 130 operations. Conclusion: Complication rates are affected considerably by the extent of surgical experience in a nonlinear and complex logarithmic manner, starting with low rates in the beginner group, peaking after further experience and then decreasing exponentially.