Newer Technique of Laryngeal Reinnervation: Superior Laryngeal Nerve (Motor Branch) as a Driver of the Posterior Cricoarytenoid Muscle

Abstract

This report analyzes the experience gained using two different techniques to reinnervate the paralyzed vocal cord. In the neurotization group, the superior laryngeal nerve (SLN) motor branch-cricothyroid muscle pedicle was used to reinnervate the posterior cricoarytenoid muscle. In the direct nerve anastomosis group, the SLN was anastomosed to the abductor branch of the recurrent laryngeal nerve (RLN), and the ansa hypoglossi (AH) to the adductor branch of the RLN. A third group of animals (control) had the right RLN sectioned without any anastomosis. About 5 to 6 months postoperatively the animals were killed painlessly and evaluated. The neurotization group revealed vocal fold mobilization on the right side to have an average of about half of the mobility of the left, normal side. After the RLN and SLN on the left were severed as well as the AH bilaterally, the vocal cord mobility was reduced to about one fourth. The direct nerve anastomosis group showed about fourfold less vocal cord mobility than the neurotization group. After the SLN, RLN, and AH were severed bilaterally, the control group showed no vocal cord mobility. The neurotization technique has been selected for further experimentation in human adults.

Reinnervation of Bilateral Posterior Cricoarytenoid Muscles Using the Left Phrenic Nerve in Patients with Bilateral Vocal Fold Paralysis

“…The nerve muscle pedicle (NMP) technique which was popularized by Tucker [1] and used in the treatment of vocal fold paralysis in earlier studies, has been abandoned since other surgeons were unable to use the technique satisfactorily [2-4]. Electrophysiological, histological, and anatomical studies have shown that the phrenic nerve is the optimal transfer nerve for reinnervation of the PCA muscle in treating patients with BVFP [5-7].…”

Partial Recovery of Respiratory Function and Diaphragm Reinnervation following Unilateral Vagus Nerve to Phrenic Nerve Anastomosis in Rabbits

“…Second, transection of the VN at the cervical level would lead to recurrent laryngeal nerve injury, which would result in hoarseness and even dyspnea because of the absence of movement on the affected side of the vocal cords [43] , [44] . However, these symptoms might be significantly improved by laryngeal reinnervation [45] , [46] . Third, 80%−90% of VN fibers are afferent (sensory) [30] , so only 10%−20% of the surface area of anastomosis would be motor fibers that could regenerate into the PN and reinnervate the diaphragm.…”

Selective reinnervation for bilateral vocal cord paralysis using the superior laryngeal nerve

“…Furthermore, the ability of the external branch of the superior laryngeal nerve (EBSLN) to drive the PCA has been previously demonstrated in a feline model. 4,5 Here, we report the first two cases of selective reinnervation of the PCA utilizing the EBSLN with good postoperative results.…”