Thyroplasty as a New Phonosurgical Technique

In an attempt to examine the surgical possibility of changing the vocal cord position and tension by reforming the thyroid cartilage, an experimental study was made using 10 adult dogs. Hoarseness produced by section of the recurrent laryngeal nerve was generally much improved by vertical incision on the thyroid ala and slipping in of the lateral cartilage segment. Four types of thyroplasty were proposed from the functional viewpoint. Their effects on the vocal cord are (1) lateral compression, (2) lateral expansion, (3) relaxation (shortening) and (4) stretching (lengthening) respectively. Possible indications for each type of thyroplasty were described with reference to specific laryngeal diseases. The advantages of thyroplasty were emphasized namely, that the intervention inside the thyroid cartilage is minimal and therefore fine and reliable adjustment is possible during surgery. Thyroplasty thus offers a new possibility in phonosurgery.