Laryngeal reinnervation for recurrent laryngeal nerve injuries caused by thyroid surgery / 中国普通外科杂志

ABSTRACT

Objective To investigate laryngeal reinnervation for recurrent laryngeal nerve injury caused by thyroid surgery. Methods Included in this series were 42 patients with recurrent laryngeal nerve injury, undergoing nerve decompression in 8 cases, end-to-end anastomosis of recurrent laryngeal nerve in 6, anastomosis of main branch of ansa cervicalis to recurrent laryngeal nerve in 21, end-to-end anastomosis of recurrent laryngeal nerve in 6 cases, phrenic nerve graft combined with nerve muscular pedicle (NMP) technique or nerve decompression in 7. All cases were subjected to preoperative and postoperative videolaryngoscopy, voice recording, acoustic analysis and electromyography. Results In 5 patients with unilateral injury and with a course less than four months, nerve decompression restored functional adductory and abductory motion of the vocal cord. Although functional motion of vocal cord was still absent in two patients receiving nerve decompression with a course longer than 4 months and in one less than 4 months, and in all cases with unilateral vocal cord paralysis receiving ansa cervicalis anastomosis and end to end anastomosis of recurrent laryngeal nerve, these procedures did result in symmetric vibration of the vocal cords and physiological phonation. Good inspiratory abductent motion of the glottis was observed on the reinnervated sides by the phrenic nerves in 6 cases with bilateral vocal cord paralysis and the vocal cord excursion was from 3 to 5 mm. On the opposite reinnervated sides, 2 cases with nerve decompression restored functional adductory and abductory motion of the vocal cord; while 4 cases with NMP technique restored only slight abductent motion or no motion. These patients have achieved sufficient airway so that exercise to tolerance for daily activities is adequate without a tracheotomy. In no case was the voice weakened, no was there any problem with aspiration. Conclusions Nerve decompression seems to be the best procedure in laryngeal reinnervation; Main branch of ansa cervicalis technique achieves satisfactory reinnervation of adductor muscles; Phrenic nerve graft yields more satisfactory vocal cord abductory motion than NMP technique. Selection of the laryngeal reinnervation protocols should depend on the course, severity, type of nerve injury.