Single-incision endoscopic thyroidectomy by the axillary approach with gas inflation for the benign thyroid tumor: retrospective analysis for a single surgeon's experience

Trans-axillary endoscopic thyroid surgery offers the advantage of a good cosmetic outcome; however, it requires a wider dissection field compared to the other endoscopic approaches or open surgery. Therefore, it might cause severe postoperative pain occasionally. To reduce the dissection field required, we perform trans-axillary single-incision endoscopic thyroidectomy (SIET) with gas inflation. The aim of this study was to present a single surgeon's experience with SIET and to investigate the learning curve of SIET.

Between June 2009 and September 2014, a total of 105 patients who underwent hemithyroidectomy for benign thyroid tumor via an SIET procedure were included in the present study. All of the procedures were performed by the same surgeon. Each patient's operative outcomes were collected and retrospectively analyzed. The cumulative summation (CUSUM) analysis was used to assess the learning curve of SIET.

No mortality or serious morbidity was observed during the study period. The adverse postoperative outcomes included wound hematoma (2 cases; 1.9 %), transient skin paresthesia (5 cases; 4.76 %), transient voice change (5 cases; 4.76 %), skin pigmentation (1 case; 0.9 %), and fibrous band of wound (1 case; 0.9 %). The overall mean operative time was 105 min, and the mean operative time in the experienced phase was 95 min. CUSUM analysis showed a decreasing trend at the 35th patient, suggesting that more than 35 cases were needed for the surgeon to gain proficiency. In 76.19 % of the cases, patients showed extreme satisfaction with the cosmetic results.

Our results showed reasonable surgical outcomes compared to previous studies on endoscopic thyroidectomy. The SIET procedure is safe and feasible for benign thyroid tumors and has an acceptable learning curve for surgeons who are proficient in conventional endoscopic thyroidectomy.