PRESERVATION OF RECURRENT LARYNGEAL NERVE INVADED BY DIFFERENTIATED THYROID-CANCER

Objective This study was undertaken to determine whether the recurrent laryngeal nerve involved in differentiated thyroid carcinoma could be preserved. Summary Background Data Few investigations have provided d efinitive results concerning preservation of the recurrent laryngeal n erve involved in thyroid cancer. Complete excision with resection of t he recurrent laryngeal nerve reportedly did not improve survival over incomplete excision in differentiated thyroid carcinoma. Methods A ret rospective study was performed with the medical records of 50 patients with differentiated carcinoma and preoperative normal vocal cord func tion to investigate outcomes of recurrent laryngeal nerve preservation including local recurrence, prognosis, and postoperative vocal cord f unction. The recurrent laryngeal nerves on 1 or both sides were preser ved in 23 patients (the preserved group), whereas the involved recurre nt laryngeal nerve of the other 27 patients was resected (the resected group). Results Backgrounds of patients were similar between the rese cted and preserved groups. The number of patients with recurrences in each group was similar, and incidence of local, regional, and distant metastatic recurrences were not different between the groups. Postoper ative overall survival of the preserved group was similar to that of t he resected group (p = 0.1208). More than 60% of patients or of nerve at risk in the preserved group restored normal vocal cord function wit hin 6 months. Some functional vocal cord movement was recognized in 80 % oi patients or of nerve at risk. All patients in the resected group including patients with nerve anastomosis showed permanent paralysis o f the ipsilateral vocal cord. Conclusions These results suggested that the recurrent laryngeal nerve, even if infiltrated by differentiated thyroid cancer, is worthwhile to preserve for maintenance of postopera tive vocal cord function without affecting the incidence of local recu rrence or prognosis.