Laryngeal Reinnervation by Ansa Cervicalis Nerve Implantation for Unilateral Vocal Cord Paralysis in Humans

Abstract

Ansa cervicalis (AC)-recurrent laryngeal nerve anastomosis (RLN) is usually not desirable for correction of paralytic dysphonia when it is difficult to find a viable distal stump of the recurrent laryngeal nerve. Nerve implantation of the thyroarytenoid muscle with the ansa cervicalis is a simple alternative method. Ten patients with unilateral vocal cord paralysis were prospectively designed to receive nerve implantation. A minimum period of 12 months after onset of paralysis was allowed to elapse to permit possible spontaneous reinnervation or compensation. Patients were followed long enough (at least 2 years) to determine if the procedure was successful. All patients were subjected to preoperative and postoperative voice recording, acoustic analysis, and videolaryngoscopy. Some of them underwent laryngeal electromyography. Ten patients underwent nerve implantation of the thyroarytenoid muscles by using the ansa cervicalis, and 8 of 10 (80%) had improved phonatory quality. Laryngeal electromyography showed that the procedure produced satisfactory reinnervation of the thyroarytenoid muscle. Nerve implantation of the thyroarytenoid muscle by the anso cervicalis is a simple and efficient alternative to nerve transfer if dense scarring at the cricothyroid articulation and lack of a viable distal stump of the recurrent laryngeal nerve preclude the procedure of nerve transfer. But careful selection of the appropriate candidate seems to be the earliest prerequisite for a successful procedure.