Intraoperative carbon nanoparticles mapping in secondary total thyroidectomy for recurrent thyroid nodules: Results of a 8-criterion case-match study (case control study).

BACKGROUND:The extent of total thyroidectomy in the management of multinodular goiter remains unclear. Compared to primary thyroidectomy, secondary total thyroidectomy is more difficult to perform and carries a significantly higher risk of postoperative complications such as recurrent laryngeal nerve (RLN) palsy or hypoparathyroidism. In this study, we aimed to evaluate the efficacy and safety of intraoperative carbon nanoparticle (CN) mapping in patients undergoing secondary total thyroidectomy. METHODS:We performed a case-matched analysis of a prospectively maintained database using 8 specific criteria to compare perioperative outcomes after primary total thyroidectomy to those after secondary total thyroidectomy with intraoperative CN mapping. The criteria included age, sex, operative procedure, RLN/parathyroid glands (PGs) exploration, preoperative vocal cord calcium abnormalities, and pathological results. Thirty-five patients underwent secondary total thyroidectomy with intraoperative CN mapping due to recurrent thyroid nodules or development of nodules suspicious for malignancy after subtotal thyroidectomy. Fifty exact matches for all 8 criteria were identified from the database in our previous study, which included records of 3078 primary thyroidectomies without CNs. Perioperative outcomes, surgical technique, and complications were analyzed. RESULTS:The RLNs were successfully identified in all 35 patients. Among three patients that experienced slight hoarseness, one had an RLN end-to-end anastomosis with subsequent improvement in the during the 12-month follow-up period. Two patients experienced changes in vocal tone, but recovered after several months. Two patients underwent parathyroid auto-transplantations, and subsequently presented with transient hypocalcaemia. Their symptoms gradually remitted within one year. Except for mean operation time, there were no statistically significant differences in complications between the primary total thyroidectomies and the secondary total thyroidectomy with CNs. CONCLUSIONS:Intraoperative CN mapping, expert knowledge of the jugular anatomy, and standardized resection procedures can minimize the incidence of complications such as RLN palsy and hypoparathyroidism after secondary total thyroidectomy.