Acoustic and perceptual evaluation of laryngeal reinnervation by ansa cervicalis transfer.

Abstract

To evaluate the acoustic and perceptual results of laryngeal reinnervation with ansa cervicalis to recurrent laryngeal nerve anastomosis. Retrospective study of voice samples from 12 patients with unilateral recurrent laryngeal nerve paralysis, treated with ansa cervicalis to recurrent laryngeal nerve anastomosis. Samples were recorded before surgery and at least 8 months after surgery. The samples were subjected to several acoustic analyses sensitive to paralytic dysphonia, including cepstral peak prominence, noise-to-harmonics ratio, and measures of frequency and amplitude perturbation. The voice samples from the patients were randomized with age- and sex-matched samples from normal subjects and judged by trained listeners for overall dysphonia, roughness, breathiness, asthenia, and strain. The preoperative and postoperative results were compared statistically, and the postoperative results were compared with the matched normal subjects. As a group, the patients showed improvement (P < .05) in cepstral peak prominence, frequency perturbation, and perceptual judgments of overall dysphonia, breathiness, and asthenia. The best results occurred in patients with isolated vocal fold paralysis. The postoperative group as a whole did not improve to the level seen in matched normals. Suboptimal results were seen primarily in patients with untreated laryngeal or extralaryngeal pathology beyond the laryngeal paralysis. These data suggest that laryngeal reinnervation has the potential to bring about a return to normal or near-normal voice in patients with isolated unilateral vocal fold paralysis.