Adduction arytenopexy: a new procedure for paralytic dysphonia with implications for implant medialization.
Arytenoid adduction was designed to enhance posterior glottal closure in patients with paralytic dysphonia by reproducing lateral cricoarytenoid muscle function. However this procedure can exaggerate normal medial rotation of the vocal process, because the agonist-antagonist function of the interarytenoid, lateral thyroarytenoid, and posterior cricoarytenoid muscles is not simulated. Therefore, a new adduction procedure (adduction arytenopexy) was devised to affix the arytenoid on the cricoid facet in a more optimal position for glottal sound production. The adduction arytenopexy procedure was designed on fresh cadavers. In this technique, the lateral aspect of the cricoarytenoid joint is opened widely and the body of the arytenoid is manually medialized along the cricoid facet. A specially designed single suture is then placed through the posterior cricoid and the body or the muscular process of the arytenoid to achieve 2-point fixation. This draws the arytenoid posteriorly, superiorly, and medially for precise positioning. The arytenoid is rocked internally on the cricoid facet, and suture tension is adjusted appropriately to simulate normal cricoarytenoid adduction. In the first study, the adduction arytenopexy was compared with the classic arytenoid adduction in 10 fresh cadaver larynges. The new arytenopexy procedure resulted in an average increase of 2.1 mm (p < .01) in the length of the musculomembranous vocal fold, whereas the classic arytenoid adduction did not reveal a significant change in length. Additionally, the adduction arytenopexy resulted in a consistently higher vocal fold and a more normally contoured arytenoid than the classic adduction procedure. The second study consisted of a clinical trial in which 12 patients, who presented with a widely patent posterior glottis, underwent adduction arytenopexy in conjunction with implant medialization. The procedure was successful in all patients, and there were minimal complications. In the third study, preoperative and postoperative vocal assessment measures (stroboscopic, aerodynamic, acoustic, and perceptual) were analyzed in 9 of the 12 patients. The most striking preoperative stroboscopic observation was that 8 of the 9 patients presented with an aperiodic vibrational flutter during phonation due to severe valvular incompetence. Postoperatively, all patients developed complete closure of the glottal chink and effective entrained oscillation of the vocal folds. This visual improvement in function was commensurate with comparable changes in most of the other objective and subjective measures of vocal function. The new adduction arytenopexy procedure closely simulates the biomechanics underlying normal glottal closure and cricoarytenoid adduction. In turn, complex implant design shapes are not necessary to achieve proper alignment of the arytenoid and the vocal fold. Because the arytenoid is properly positioned prior to the medialization, implants can be sized more precisely and are unencumbered by an anterior thyroid lamina suture. These procedural innovations resulted in enhanced entrained oscillation of the glottal valve and, in turn, improved laryngeal sound production.
Department of Otology and Laryngology, Harvard Medical School, Boston, Massachusetts, USA.
SourceThe Annals of otology, rhinology & laryngology. Supplement 173: 1998 Sep pg 2-24
Prostheses and Implants
Vocal Cord Paralysis
Pub Type(s)Clinical Trial
Research Support, U.S. Gov't, P.H.S.