Reviewing and Refining Surgical Interventions for Glottic Insufficiency

Glottic insufficiency is the primary anatomic etiology of dysphonia and a central abnormality of disorders such as vocal fold paralysis, presbylaryngis, and vocal fold scar. Treatment is primarily surgical and directed towards placing the affected fold in a midline position conducive to glottic closure and vocal fold vibration. Two open procedures offering permanent medialization include type I thyroplasty and arytenoid adduction. Thyroplasty uses an implant to medialize the affected vocal fold while arytenoid adduction uses a suture technique to accomplish the same goal. Though valuable and capable of providing a good outcome, both procedures are technically challenging and highly invasive. This series of seven studies used the excised larynx bench apparatus to perform a systematic, multiparametric assessment of current treatments and evaluate new devices which could simplify the procedures. Specifically, an adjustable silicone balloon implant which can be inserted via a minimally invasive minithyrotomy and a suture-wire complex which can be used to perform arytenoid adduction from a less invasive anterior approach were investigated. Experiments were performed using excised canine larynges and treatments were compared to both simulated unilateral vocal fold paralysis as well as normal conditions. Additionally, a range of aerodynamic, acoustic, and videokymographic parameters were employed and their ability to describe changes in phonation due to vocal fold medialization individually and collectively was determined. Vocal efficiency and perturbation parameters were demonstrated to be particularly effective at describing changes in laryngeal function as the arytenoid is rotated during arytenoid adduction. The wedge-shaped adjustable balloon implant provided effective medialization, closing the glottic gap and restoring normal vocal fold vibration. The suture-wire complex was effective for performing arytenoid adduction from an anterior aspect, thus eliminating the most challenging aspect of the procedure while not sacrificing outcome quality as judged by comparison to the traditional procedure. Further studies evaluating host response and long-term stability of these devices in living animals and human subjects are warranted.