Vocal cord paralysis associated with anterior cervical fusion: considerations for prevention and treatment

Abstract

In a series of 375 patients with anterior cervical fusions, long-term follow-up results complete with laryngeal examination were obtained in 102 patients. One patient was found to have an inferior laryngeal nerve palsy, and one had a superior laryngeal nerve palsy. Both deficits were thought to be the result of surgical trauma. Measures to minimize the incidence of vocal cord paralysis include careful surgical technique and knowledge of the surgical anatomy of the laryngeal nerves. Suggestions are given for the assessment of postoperative hoarseness, and for the management of vocal cord paralysis.

Is dysphonia permanent or temporary after anterior cervical approach?

“…Vocal cord paralysis is a rare neurological complication than dysphagia in cervical surgery. Temporary unilateral vocal cord paralysis after ACA was reported in the range between 0.98 and 8% and the incidence of permanent paralysis was between 0.15 and 3.5% [3,6,9,14,17,33]. In our series, temporary unilateral vocal cord paralysis was 1.27% and no permanent vocal cord paralysis was observed.…”

“…Increased cuff pressures may impinge upon the nerve, pushing it against the thyroid lamina. Bulger et al [3] have suggested that vocal fold paralysis during ACDF may be due to endotracheal intubation. Intubation trauma can cause both permanent and temporary vocal fold paralysis.…”

“…Although dysphonia may be permanent, most cases are temporary which are lasting for weeks or months. Some proposed mechanisms of this complication include direct surgical trauma, nerve division, or ligature, pressure or stretchinduced neuropraxia, postoperative edema [3,11,18,25], and endotracheal tube-related vocal fold paralysis is described. We retrospectively reviewed the cases with dysphonia after anterior cervical surgery to evaluate the causes and prognosis of this complication.…”

Surgical anatomy of the internal branch of the superior laryngeal nerve

“…Routinely the main trunk and posterior descending branch of the ibSLN was preserved in supraglottic laryngectomy by identification of the main trunk in the viscero-vertebral angle medial to the carotid bifurcation [5]. The rate of SLN palsy varies from 9 to 14% in thyroid surgery [10], from 1 to 4.5% in carotid endarterectomy operations [8], and 8% in anterior cervical fusion operations [4]. Injury to the ibSLN results in impairment of the laryngeal cough reflex [12,18].…”

Value of intraoperative neurophysiological monitoring to reduce neurological complications in patients undergoing anterior cervical spine procedures for cervical spondylotic myelopathy

“…Dysphonia secondary to recurrent laryngeal nerve palsy could be secondary to indirect stretch or focal pressure on the nerve 30 . The incidence of vocal cord paralysis varies from 1-13 % depending on the type of study and evaluation methodology 2,31,32 . Prospective studies which utilized objective methods such as indirect laryngoscopy and 3 months follow up reported an incidence rate of 13.3% 31 .…”