Sling arytenoid adduction

The purpose of this study was to describe a simplified arytenoid rotation technique and to test its applicability in excised human larynges. A non-absorbable monofilament thread is slung around the muscular process of the arytenoid cartilage through an external approach. During visual control through flexible endoscopy, two needles and a wire loop needle threader are the only instruments needed. Thread tensioning and fixation results in a stabilized arytenoid adduction. This technique avoids cricothyroid joint disarticulation and leaves the thyroid cartilage intact. The practicability of the technique was proven in five excised larynx experiments. In two clinical cases, the muscular process was slung and pulled with a monofilament thread. Tension in the vector direction parallel to the LCA muscle showed an effective and stable arytenoid rotation with complete closure of the posterior glottis. The rotational effect following sling arytenoid adduction (SAA) is similar to conventional arytenoid adduction surgery outcome. However, SAA is performed from an external approach and avoids dissection of cartilage. Challenging dissections to reach the muscular process are avoided. In some cases of unilateral vocal fold immobility, arytenoid rotation may be performed by using the SAA technique, which allows for an external and extralaryngeal approach. Further studies should assess the clinical value of this technique. In principal, the wire loop needle threader can also be employed for external vocal fold lateralization procedures.     

Visual observations of glottal configuration and vocal outcomes in arytenoid adduction

Arytenoid adduction procedures involve approximation of the arytenoid cartilages with the goal of reducing posterior glottal gap size and improving voice. However, voice outcomes after arytenoid adduction are not always optimal and may be improved by precise use of suture placements, forces, and direction angles. The development of intraoperative methods of assessing optimal suture direction appears critical for achieving the best voice outcome. The goal of this study was to examine the relationship of visual classification of glottal configuration, digital measures of the glottis, acoustic and aerodynamic measures, and voice outcome. Our results suggested that visual classification of glottal configuration was not useful in distinguishing voice outcome, except for cases in which there was a large posterior glottal gap. In contrast, acoustic and aerodynamic measures were related to digitized glottal measures and may be developed into a useful method of intraoperative monitoring.     

Physiologic assessment of arytenoid adduction.

Arytenoid adduction as described by Isshiki is a surgical technique used to improve vocal quality by adducting the arytenoid cartilage of a paralyzed vocal fold, medializing the fold, and closing the posterior glottic aperture. Surgical results of this operation were evaluated by preoperative and postoperative voice recordings, laryngoscopy, and stroboscopy. Objective measurements of vocal jitter, shimmer, and signal to noise ratio were done to assess changes in the vibratory patterns, and analysis of data from 12 patients revealed improved glottic function postoperatively. Often an anterior medialization procedure, primarily a type I thyroplasty, was used to supplement the posterior medialization achieved by adduction of the arytenoid. Arytenoid adduction is recommended as an effective and reliable treatment for posterior glottic insufficiency.     

Glottic cancer with extension to the arytenoid

Hemilaryngectomy with removal of a greater part or all of the arytenoid was done in 79 patients with good functional results with an overall cure rate and salvage rate of 94 percent. The survival rate for the primary modality of therapy was 90 percent.     

Development of endoscopic arytenoid adduction using cricoid implant

OBJECTIVES: We sought to develop a less-invasive alternative to conventional arytenoid adduction using a cricoid implant. METHODS: We performed a preliminary study with excised human and canine larynges. A nail-shaped stainless steel rod and an insertion device were designed for an in vivo animal trial. After unilateral recurrent laryngeal denervation surgery in 5 adult mongrel dogs, the implants were inserted endoscopically through a small mucosal incision over the cricoarytenoid joint. Acoustic and aerodynamic data were obtained from each animal before serial euthanasia followed by examination of the excised larynges. RESULTS: The canine cricoid cartilage demonstrated adequate marrow space for implantation. We found that the arytenoid cartilage was successfully medialized and tightly fixed over a sufficient period of time just by inserting an implant in the cricoid cartilage. The animal study showed that the implantation procedure was relatively easy and relatively safe. Acoustic and aerodynamic studies confirmed the functional improvement of the voice. Histopathologic study revealed a favorable tissue response to the implant. CONCLUSIONS: Endoscopic arytenoid adduction using a cricoid implant is feasible and could be a noninvasive surgical option for the treatment of unilateral vocal fold paralysis.     

Complications of type I thyroplasty and arytenoid adduction

OBJECTIVES/HYPOTHESIS: Unilateral vocal fold paralysis resulting in glottal incompetence can cause significant morbidity attributable to impaired speech, swallowing, and ability to protect the airway. Type I thyroplasty in combination with arytenoid adduction is a proven technique for medialization of the paralyzed vocal fold but must be evaluated in light of potential complications following laryngeal framework surgery. STUDY DESIGN AND METHODS: The charts of 237 patients who underwent unilateral vocal fold medialization surgery between July 1, 1991, and August 30, 1999, at a tertiary care cancer referral center were retrospectively reviewed. RESULTS: There were 98 cases of type I thyroplasty alone and 96 cases of type I thyroplasty with arytenoid adduction. The two groups had similar patient characteristics. Mean time of surgery (45 vs. 73 min, P <.0001) and length of hospital stay (1.1 vs. 1.8 d, P <.0001) were increased when arytenoid adduction was performed. Overall improvement of symptoms was similar in both groups (93%-94%), but posterior glottic closure appeared subjectively improved when arytenoid adduction was used (P =.0054). Overall complication rates were slightly higher in the arytenoid adduction group (14% vs. 19%), primarily because of transient vocal fold edema and wound complications (9 vs. 19 cases), but the increase was not statistically significant (P =.1401). Complications warranting medical or surgical intervention occurred in 8% of cases. Two patients who underwent type I thyroplasty with arytenoid adduction required tracheotomy as a consequence of postoperative complications. The three patients who had extrusion of the implant underwent type I thyroplasty alone. CONCLUSION: Using the appropriate technique, the potential benefits of improved glottic function following type I thyroplasty with arytenoid adduction outweigh the small risk of significant complications observed.     

Aerodynamic, acoustic, and vibratory comparison of arytenoid adduction and adduction arytenopexy

HYPOTHESIS: Adduction arytenopexy (AP) with thyroplasty provides improved physiologic placement of the vocal fold and therefore provides improved acoustic, aerodynamic, and vibratory function as compared with arytenoid adduction (AA) with thyroplasty. METHODS: Five cadaveric human larynges were prepared by removing supraglottic tissues and fixing the nontest vocal fold medially on the cricoid facet with a needle in a physiologic phonating position. Each test vocal fold was then sequentially tested using an excised larynx phonation system, first with AA with silastic medialization and then converted to AP without changing the contralateral fold position or silastic wedge. The excised larynx setup allowed for simultaneous collection of data, specifically subglottic pressure (including measurement of phonation threshold pressure [PTP]), mean airflow, acoustic output, and full-frame high-speed digital video. RESULTS: Aerodynamic evaluation was similar for each group with similar subglottic pressure versus output curves. Conditions involving AP typically had PTP values that were 80% of that for comparable AA conditions. Acoustic evaluation revealed differences between the two groups. Each AA was found to be vibrating with two dominant frequencies with their associated harmonics. Each AP vibrated at a single dominant frequency with its harmonics. CONCLUSION: AP provides improved vocal outcomes by decreasing system noise and decreasing PTP, which may lead to a stronger glottal signal with decreased vocal effort.     

Useful landmarks in arytenoid adduction and laryngeal reinnervation surgery

OBJECTIVE: Knowledge of the location of the muscular process of the arytenoid cartilage and the recurrent laryngeal nerve is essential to performing a successful arytenoid adduction and laryngeal reinnervation surgery. We describe external landmarks useful in locating these structures. STUDY DESIGN: Cadaveric laryngeal dissection. METHODS: Posterior laryngeal dissection was performed in 16 human larynges. The position of the muscular process of the arytenoid was measured bilaterally relative to the inferior and superior borders of the thyroid lamina. The recurrent laryngeal nerve was followed distally from slightly below the level of the cricothyroid joint to its genu where its vertical course changes to an oblique intralaryngeal course. RESULTS: The muscular process of the arytenoid was usually found halfway between the roots of the superior and inferior cornu of the thyroid lamina. The recurrent laryngeal nerve was found just deep to the cricothyroid joint and lateral to the posterior cricoarytenoid muscle. There were no other nerves in this area. CONCLUSIONS: This study finds that the superior and inferior borders of the thyroid lamina are useful intraoperative landmarks to locate the muscular process of the arytenoid. The cricothyroid joint provides a good starting point to locate the recurrent laryngeal nerve, which can be identified slightly deeper between it and the posterior cricoarytenoid muscle.     

Glottal configuration,acoustic, and aerodynamic changes induced by variation in suture direction in arytenoid adduction procedures

Arytenoid adduction is a phonosurgical procedure in which the arytenoid cartilages are approximated to reduce posterior glottal gap size and improve voice. Voice outcomes following arytenoid adduction are not always optimal. The goal of this study was to systematically vary suture direction and force of pull on the arytenoid cartilages in a human excised laryngeal model to determine the optimal combination of factors for reducing glottal gap and improving voice. Several factors demonstrated significant effects. Changes in suture direction and force of pull affected glottal configuration in both the horizontal and vertical planes. Increased force of pull on the muscular process resulted in increased adduction of the vocal process for all suture directions. Changes in suture direction and force of pull also affected acoustic and aerodynamic measures of induced voice. Therefore, voice outcomes can be optimized with arytenoid adduction if the vocal fold plane is accurately adjusted.