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 cricoaryte noid muscle function. However, this procedure can exaggerate normal me dial rotation of the vocal process, because the agonist-antagonist fun ction of the interarytenoid, lateral thyroarytenoid, and posterior cri conrgtenoid muscles is not simulated. Therefore, a new adduction proce dure (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 o pened widely and the body of the arytenoid is manually medialized alon g 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 p osteriorly, superiorly, and medially for precise positioning. The aryt enoid is rocked internally on the cricoid facet, and suture tension is adjusted appropriately to simulate normal cricoarytenoid adduction. I n the first study, the adduction arytenopexy was compared with the cla ssic arytenoid adduction in 10 fresh cadaver larynges. The new aryteno pexy procedure resulted in an average increase of 2.1 mm (p < .01) in the length of the musculomembranous vocal fold, whereas the classic ar ytenoid adduction did not reveal a significant change in length. Addit ionally, the adduction arytenopexy resulted in a consistently higher v ocal fold and a more normally contoured arytenoid than the classic add uction procedure. The second study consisted of a clinical trial in wh ich 12 patients, who presented with a widely patent posterior glottis, underwent adduction arytenopexy in conjunction with implant medializa tion. The procedure was successful in all patients, and there were min imal complications. In the third study, preoperative and postoperative vocal assessment measures (stroboscopic, aerodynamic, acoustic, and p erceptual) were analyzed in 9 of the 12 patients. The most striking pr eoperative stroboscopic observation was that 8 of the 9 patients prese nted with an aperiodic vibrational flutter during phonation due to sev ere valvular incompetence. Postoperatively, all patients developed com plete closure of the glottal chink and effective entrained oscillation of the vocal folds. This visual improvement in function was commensur ate with comparable changes in most of the other objective and subject ive measures of vocal function. The new adduction arytenopexy procedur e 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 unencumbe red 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.