研究会のご案内
リエゾンラボ研究会
発表内容

Title:
LARYNGEAL REINNERVATION – NEW HORIZONS IN TREATMENT OF VOCAL FOLD PARALYSIS

Eiji Yumoto, MD
Department of Otolaryngology ? Head and Neck Surgery, Graduate School of Medicine
Kumamoto University, Kumamoto, Japan

Abstract:
  Unilateral vocal fold paralysis (UVFP) severely compromises patients’ vocal function, significantly impacting their general health status and social activities. Improvement in breathy dysphonia is usually obtained by implementing various kinds of phonosurgical procedures. However, not all patients recover “normal” or “near-normal” voices after surgery. “Near-normal” voices can be attained by providing the immobile vocal fold with the median location and the symmetrical volume, tension, and mucosal viscoelasticity of the unaffected vocal fold. Because the phonosurgical procedures offer “static” adjustment of these features, the thyroarytenoid (TA) muscle, a key muscle for eliciting vocal fold vibration, does not work as the body of the immobile vocal fold, and thus results in little contribution to voice production and tuning.
  The author believes that laryngeal reinnervation is indispensable to provide the affected vocal fold with above-mentioned conditions, and have been performing laryngeal reinnervation procedures on patients with severely breathy dysphonia due to UVFP. Such procedures include direct anastomosis of the severed ends of the recurrent laryngeal nerve (RLN), anastomosis between the RLN stumps by interposing a foreign nerve section such as the great auricular nerve, anastomosis between the peripheral RLN stump and the ansa cervicalis nerve, and nerve-muscle pedicle (NMP) flap implantation.
  In the presentation, the author will mention the importance of laryngeal reinnervation to retrieve “near-normal” voice of each patient, indications of each reinnervation procedures and arytenoid adduction, and results of the reinnervation surgeries. Special focus will be placed on a NMP method aiming at establishment of reinnervation of the thyroarytenoid muscle.
  Although a NMP method was first reported in 1970’s, it has been rarely performed clinically because of inconsistent or poor outcome. The author refined the technique of harvest and implantation of a NMP flap, and studied, using rat denervation model, the effect of NMP implantation into the TA muscle as one of the methods to facilitate laryngeal reinnervation. The results confirmed the effectiveness of the method for recovering from atrophic changes even in the long-term denervated TA muscle. The results of these basic research studies will be presented in detail.