Chapter 15 Vocal Fold Medialization, Arytenoid Adduction, And

Chapter 15 Vocal Fold Medialization, Arytenoid Adduction, and Reinnervation Andrew Blitzer, Steven M. Zeitels, James L. Netterville, Tanya K. Meyer, and Marshall E. Smith Restoration of vocal function with laryngeal framework sur- Thyroplasty Type I gery (laryngoplastic phonosurgery) was introduced at the Thyroplasty type I (Fig. 15.1) is the most widely used of beginning of the 20th century. Today, these procedures have Isshiki’s original thyroplasty techniques. It involves creating emerged as the dominant surgical management approach for a rectangular cartilaginous window at the level of the true the treatment of the aerodynamic incompetence and acoustic vocal fold and using cartilage, Silastic, Gore-Tex, or other deterioration associated with vocal fold paralysis/paresis. implant material to medialize the true vocal fold. This pro- Other indications include cancer defects, vocal fold scar, sul- cedure achieves closure of the musculomembranous vocal cus vocalis, bowing associated with vocal fold atrophy, laryn- fold only; arytenoid position is not appreciably altered by geal trauma, and neuromuscular disorders including abductor the implant. Thyroplasty type I is a relatively simple and spasmodic dysphonia and parkinsonism. Laryngeal frame- reversible procedure that is ideally performed with local work surgery has also been employed to alter pitch for gender anesthesia to facilitate fine-tuning of the voice with precise reassignment; however, this topic is not discussed here. placement of the implant material. There have been a large Although medialization of the musculomembranous number of manuscripts describing a multitude of variations vocal fold by means of rearranging the laryngeal cartilage of the original procedure, primarily introducing different framework was described by Payr1 in 1915, and others in implant materials and their placement. As thyroplasty type the mid–20th century,2,3 Isshiki et al4–6 championed the I does not primarily influence arytenoid position, this pro- systematic analysis and laryngoplastic treatment of glottal cedure is often coupled with an arytenoid adduction or ary- incompetence in the 1970s. He designed his medialization tenopexy to close both the anterior (musculomembranous) procedure of the musculomembranous vocal fold with the and posterior (cartilaginous) glottis. use of a synthetic implant in 1974. In 1978, Isshiki et al5 designed the arytenoid adduction procedure to treat patients with large glottal gaps secondary to a malpositioned arytenoid. One of his outstanding contri- butions is that he taught surgeons that laryngeal framework procedures could be done with facility utilizing local anesthesia with sedation. The concept that the cricoarytenoid joint could be dissected and manipulated under local anesthesia to allow for phonatory feedback was revolutionary. Based on this seminal work, the adduction arytenopexy2,7–9 and cricothyroid subluxation7,8,10 procedures were introduced to further enhance phonatory reconstruction. ♦ Laryngeal Framework Surgery Isshiki’s Classification Isshiki6 described four basic surgical procedures that he termed thyroplasty types I to IV for altering the conformation of the thyroid cartilage and the arytenoid adduction, which Fig. 15.1 A small implant is placed lateral to the inner perichondrium attempts to close the posterior (cartilaginous) glottis. of the thyroid lamina. 127 128 III Diseases and Treatment Thryoplasty Types II to IV the outlined steps in any described technique is secondary to a basic understanding of the physiologic phonating posi- Thyroplasty type II is a procedure in which the posterolat- tion of the vocal cord. eral thyroid lamina is lateralized; there are few indications Unless contraindicated, some authors start patients on a for its use. Thyroplasty type III is used to lower the vocal Medrol DosePack the day before surgery, and patients are pitch by shortening the anteroposterior (AP) dimension of given 0.2 mg/kg of Decadron 1 hour prior to the procedure. the glottis. The primary function is to release vocal fold This helps to minimize intraoperative swelling, which can tension to lower pitch. Conversely, thyroplasty type IV interfere with determining the implant size, and reduces increases the AP dimension of the glottis, thereby increas- postoperative airway swelling. ing the tension on the vocal folds and raising the vocal The anesthetic preparation of the patient is extremely pitch. Thyroplasty types III and IV have been used in gender important. It is very easy to oversedate the patient, leading to reassignment surgery to bring the fundamental frequency slurred lethargic speech. With slight oversedation the muscle into the normal range for the newly assigned sex. tone of the hypopharynx grows weak, making it very diffi- cult to see the vocal folds on the monitor, or judge voice Arytenoid Adduction improvement in the lethargic patient. The majority of patients need only a few milligrams of Versed to undergo the Arytenoid adduction was described by Isshiki et al5 as a way entire procedure. It is critical to have an alert and oriented of mimicking the medializing effect of the lateral cricoary- patient to obtain good results. Some anesthesiologists prefer tenoid muscle on the vocal process. A paralyzed arytenoid to administer intravenous propofol, which can be quickly tends to fall forward and laterally on the cricoid facet, reversed when patient cooperation is necessary, and then the shortening the AP length of the vocal fold and moving the patient can be quickly sedated after implant placement. arytenoid away from the midline. The classic arytenoid Once the patient is mildly sedated, the patient’s nose is adduction procedure is performed under local anesthesia with anesthetized by instilling 4 cc of 5% cocaine into the nasal sedation by exposing the posterior aspect of the thyroid cavity. A flexible fiberoptic scope is introduced transnasally, lamina. The cricoarytenoid joint is identified, and a suture is suspended above the patient, and attached to the video placed through the muscular process of the arytenoid and monitor system so that the larynx can be visualized on the passed anteriorly through the thyroid lamina, thereby rotat- monitor during the entire procedure (Fig. 15.2). Other sur- ing the vocal process medially to meet the opposite vocal geons pass an endoscope at critical times during the proce- process during phonation. Prior to the conclusion of the dure when visualization is important. This makes the patient surgical procedure the position is visually verified by means more comfortable during the procedure. of a flexible fiberoptic laryngoscope. Preoperative intramuscular Robinal is administered to decrease the pharyngeal secretions during the procedure. To Principles and Theory of Laryngeal increase the likelihood of success, one needs both auditory and visual feedback, to access the position of the vocal fold Framework Surgery during testing. Intraoperative visualization of the vocal fold The ideal procedure(s) to treat aerodynamic glottal incom- provides two distinct advantages: (1) The relative position of petence that is associated with paralytic/paretic dysphonia the vocal fold within the window can be identified early in should attempt to simulate the normal vocal fold position the procedure. (2) Initial hyperfunctional, pressed, strained during phonation with regard to the following interdepend- voice, can be very confusing to the surgeon unless he can ent parameters: (1) position of the musculomembranous observe the position of the vocal fold on the monitor. In this region in the axial plane, (2) position of the arytenoid in the axial plane, (3) height of the vocal fold, (4) length of the vocal fold, (5) contour of the vocal fold edge in the musculomembranous region, (6) contour of the vocal fold edge in the arytenoid region, and (7) mass and viscoelasticity of the vocal fold. Furthermore, the procedure(s) ideally should be easy to perform, associated with few complications, reliable, reversible, and not threatening to the airway.11 The basic technique for medialization laryngoplasty is very similar for each of the implant materials. If one understands the fundamental principles behind placing the vocal cord into the physiologic phonating position, the choice of implant material is of secondary importance. One can achieve very good results with almost any implant, if the principles outlined below are adhered to. Some implants due to their size con- straints may make it harder to place the vocal fold in the correct position. Other implants offer initial excellent voice Fig. 15.2 The flexible nasolaryngoscope, suspended above the patient, results, but are not stable and may move from the initial and attached to the video monitor, is used to view the position of the location with delayed decrease in voice quality. Following vocal cord throughout the procedure. 15 Vocal Fold Medialization, Arytenoid Adduction, and Reinnervation 129 setting, with the vocal fold displaced toward the midline, the hyperfunctional state of the larynx can be readily seen on the monitor. As outlined below, the patient is coached to relax his larynx during continued voice testing, until the hyperfunctional state is released. This slow, relaxation of the supraglottic larynx is seen on the monitor as the voice begins to improve. In the rare patient, where the hyperfunctional voice does not break, one can complete the operation, by observing the television monitor and placing the paralyzed vocal fold in the

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