Arytenoid abduction for bilateral vocal fold immobility

Enhanced Abductor Function in Bilateral Vocal Fold Paralysis with Muscle Stem Cells

INTRODUCTION

Patients with bilateral vocal fold paralysis (BVFP) experience airway obstruction because of loss of abductor function of posterior cricoarytenoid (PCA) muscles. We previously reported that implantation of autologous muscle progenitor (stem) cells into thyroarytenoid muscles during reinnervation resulted in improved adductor function. In this study, that same approach was applied to treating PCA muscles in a canine model of BVFP.

DESIGN

Animal study.

METHODS

Two canines underwent baseline measures of glottal resistance (GR), then complete transection and suture repair of both recurrent laryngeal nerves. Muscle stem cells were isolated from skeletal muscle and cultured. Two months later, GR was measured, and then 107 stem cells were implanted into one PCA muscle of each animal. After four more months, GR and glottal opening force (GOF) were measured and the muscles were harvested for histologic study. One control dog underwent the same procedures without stem cell implantation, for comparison.

RESULTS

GR increased by 21%-25% over baseline at 2 months, but after stem cell implantation, improved to 10%-14% over baseline at 6 months. PCA muscle strength, as determined by GOF, was 61%-65% on control sides (no stem cells), and 78%-83% on treated sides (with stem cells). Histology confirmed survival of stem cells and a 50% higher rate of innervation of motor endplates in the stem cell treated sides.

CONCLUSION

Autologous muscle progenitor (stem) cells show promise as a potential new therapy for patients with bilateral vocal fold paralysis. Additional studies are needed to determine the optimal number of cells, timing of implantation, and other variables before launching a clinical trial.

LEVEL OF EVIDENCE

NA (animal study) Laryngoscope, 134:324-328, 2024.

The Management in Patients With Bilateral Vocal Fold Immobility: 15 Years' Experience at a Tertiary Centre

OBJECTIVE

In order to correct the varying vocal fold positions to meet the various clinical requirements in patients with bilateral vocal fold immobility, we present pertinent surgical methods to treat them.

MATERIALS AND METHODS

From 2005 to 2020, 115 patients diagnosed with bilateral vocal fold immobility were addressed for ventilation in 89 patients and for phonation in 26 patients. In the ventilation surgery group, all the neurogenic subjects received mere suture lateralization (SL) procedures and the mechanical ones underwent arytenoid release (AR) plus SL procedures if the cricoarytenoid joint fixation (CAJF) could be confirmed before operation. In the phonation group, neurogenic subjects received nonsurgical treatment and the mechanical ones underwent AR plus arytenoid adduction (AA) procedure. The decannulation rate and respiratory comfort rate for each subgroup will be calculated and the phonatory tests were conducted.

RESULTS

In the ventilation group, 55% (49/89) of subjects received related surgeries. Mere SL offered 40 successful decannulation or respiratory comfort in 42 neurogenic subjects (95.2%). The single episode rate was high as 95%. An AR plus SL procedure also obtained 100% of decannulation or respiratory comfort with a single episode of surgical procedure if the CAJF could be confirmed preoperatively. In the phonation group, 15% (4/26) of subjects received appropriate surgeries. Single AR plus AA procedures also led to 100% (4/4) of the appropriate candidates serviceable sound.

CONCLUSION

SL procedure keeping intact laryngeal mucosa usually offered permanent glottis enlarging effect or decannulation with a single episode of procedure. The use of arytenoid release for CAJF has led to remarkable advances in the ultimate surgical outcomes of both the ventilation and phonation in terms of decreasing revision surgeries.

LEVELS OF EVIDENCE

level 4.

A Novel Endoscopic Arytenoid Medialization for Unilateral Vocal Fold Paralysis

OBJECTIVES/HYPOTHESIS

Arytenoid adduction (AA) has been indicated for unilateral vocal fold paralysis (UVFP) patients with vertical vocal fold height mismatch and/or large posterior glottic gaps that are unable to be adequately addressed by anterior medialization techniques. Although AA offers several advantages over other methods, it is technically challenging and involves significant laryngeal manipulation of the cricoarytenoid joint. A novel, minimally invasive endoscopic arytenoid medialization technique is presented for the closure of the posterior commissure.

STUDY DESIGN

Prospective case series.

METHODS

Seventeen consecutive patients were diagnosed and treated with unilateral endoscopic arytenoid medialization (EAM) combined with injection laryngoplasty because of unilateral vocal fold paralysis. Jitter, shimmer, harmonics-to-noise ratio (HNR), maximum phonation time (MPT), fundamental frequency (F₀ ), Voice Handicap Index (VHI), peak inspiratory flow (PIF), and quality of life (QoL) were evaluated preoperatively, 1 month, and 1 year after EAM.

RESULTS

Jitter, shimmer, HNR, and MPT significantly improved and remained stable 1 year after the intervention. F₀ and PIF remained unchanged. Significant improvements in VHI and QoL demonstrated patient satisfaction with voicing and respiratory functions.

CONCLUSIONS

Endoscopic arytenoid medialization is a quick, minimally invasive solution for unilateral vocal fold paralysis. With simultaneous augmentation of the vocal fold, it provides a complete glottic closure along the entire vocal fold in UVFP patients.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E903-E910, 2021.

Surgical Options for Pediatric Bilateral Vocal Cord Palsy: State of the Art

Management of pediatric bilateral vocal cord palsy (BVCP) is a controversial and challenging topic. It may represent a severe obstructive condition usually associated with respiratory distress, and, in such condition, tracheostomy has been considered the gold standard for a long time. Many surgical options have been described and used to increase the glottic space in BVCP (1), with ongoing research of less invasive techniques. The challenge and current trend in our department and in many major pediatric centers is to avoid tracheotomy through an early treatment. Many techniques introduced in the last decade reduced the number of tracheotomies and increased the decannulation rate. Furthermore, we observed a recent increase in attention to preserve the quality of the voice with new techniques, such as endoscopic arytenoid abduction lateropexy which is in our opinion an important innovation to improve glottic space with satisfactory voice results. We present a review of the literature about the evolution of the treatment options for pediatric BVCP during the years.

Widening of posterior glottis through rotation of the arytenoid on its axis: Report of nine cases

INTRODUCTION

Bilateral vocal folds' immobility is a challenge in laryngology. Multiple procedures have been proposed to improve breathing by statically enlarging the glottal airway, what also results in loss of voice and aspiration. We proposed a technique to enlarge the posterior glottis by rotating the arytenoids on its axis, imitating the function of the posterior cricoarytenoid muscle, with the objective of evaluating the results regarding decannulation, voice quality, and bronchoaspiration.

METHODS

This study is a clinical case series of patients with bilateral vocal fold paralysis who underwent an arytenoid rotation surgery at a single tertiary university care institution between 2011 and 2017. Data were prospectively collected and was complemented with information from medical charts. Patients were assessed for decannulation, dyspnea, posterior glottic opening, quality of voice, and swallowing disorders.

RESULTS

Nine patients were included in the study. Out of three patients who required tracheostomy, two were successfully decannulated. Six patients reported a significant improvement in their dyspnea, while four patients reported a worsening of their voice. The stroboscopy evidenced a posterior glottic opening of at least 7 mm in six patients. Eight patients had no aspiratory symptoms, and the acoustic analysis showed that only one patient has a normal voice.

CONCLUSION

The arytenoid rotation on its axis by imitating the posterior cricoarytenoid muscle preserves the physiological functions of the larynx, which allows sufficient opening of the posterior glottis for breathing, and could alter in a lesser extent the anterior glottis to maintain a good quality of voice and swallowing.

[The diagnostics and treatment of bilateral paralysis of the larynx]

The objective of the present study was to consider the currently available methods for the diagnostics and treatment of the patients presenting with bilateral paralysis of the larynx of various etiologies. We undertook the analysis of the publications in the domestic and foreign scientific literature concerning diagnosis and treatment of bilateral paralysis of the larynx. It was found that despite the existing modern high-tech diagnostic technologies and the variety of surgical methods for the treatment of this condition, the problem of diagnostics, management, and rehabilitation of the patients suffering from bilateral paralysis of the larynx remains a serious challenge for the researchers and clinicians that requires further investigation of this pathology. For the correct and timely diagnosis of bilateral paralysis of the larynx, the comprehensive evaluation of the functional state of the neuromuscular apparatus of the larynx is necessary. The key prerequisites for the success of the surgical intervention are its timeliness and the choice of the optimal surgical modalities.

Current Treatment Options for Bilateral Vocal Fold Paralysis: A State-of-the-Art Review

Vocal fold paralysis (VFP) refers to neurological causes of reduced or absent movement of one or both vocal folds. Bilateral VFP (BVFP) is characterized by inspiratory dyspnea due to narrowing of the airway at the glottic level with both vocal folds assuming a paramedian position. The primary objective of intervention for BVFP is to relieve patients’ dyspnea. Common clinical options for management include tracheostomy, arytenoidectomy and cordotomy. Other options that have been used with varying success include reinnervation techniques and botulinum toxin (Botox) injections into the vocal fold adductors. More recently, research has focused on neuromodulation, laryngeal pacing, gene therapy, and stem cell therapy. These newer approaches have the potential advantage of avoiding damage to the voicing mechanism of the larynx with an added goal of restoring some physiologic movement of the affected vocal folds. However, clinical data are scarce for these new treatment options (i.e., reinnervation and pacing), so more investigative work is needed. These areas of research are expected to provide dramatic improvements in the treatment of BVFP.

Laryngeal pacing for bilateral vocal fold paralysis: Voice and respiratory aspects

OBJECTIVE

To evaluate the effects of neurostimulation with the laryngeal pacemaker (LP) system in patients with bilateral vocal fold paralysis (BVFP) in terms of voice quality and respiratory function.

STUDY DESIGN

Feasibility study, first-in-human, single-arm, open-label, prospective, multicenter study with group-sequential design and 6-month follow-up period, as described in details in our previous publication.

METHODS

Nine symptomatic BVFP subjects were unilaterally implanted with the LP system at three study sites in Germany and Austria. Subjective and objective voice function, spirometric parameters other than peak expiratory/inspiratory flow (PEF/PIF), and PEF-meter self-assessment were evaluated pre- and 6 months postimplantation.

RESULTS

In general, the LP system did not considerably change the voice quality of the implanted patients. Only the sound pressure level range improved significantly 6 months postimplantation (P = 0.018). The LP system implantation did not affect the glottal closure configuration, the duration of the closed phase, and the mucosal wave of the implanted side. The evaluated spirometric parameters were not significantly affected by laryngeal pacing, whereas PEF meter self-assessment showed a stable and significant (P = 0.028) improvement of the PEF within a week upon activation of the LP system.

CONCLUSION

Neurostimulation with the LP system results in an immediate and stable PEF improvement, without negative effects on the voice quality. The PEF meter self-assessment confirmed the spirometry results of the PEF. The stimulated abduction did not affect the glottal closure during phonation. These results should be confirmed in larger and more homogenous patient cohorts.

LEVEL OF EVIDENCE

2b Laryngoscope, 127:1838-1844, 2017.

Magnetic Control of the Glottic Opening in an Ex Vivo Sheep Larynx Model: A Preliminary Study

OBJECTIVE/HYPOTHESIS

So far, a number of techniques have been described for the treatment of bilateral vocal fold paralysis. These techniques were reported to be successful in maintaining an adequate airway but also found to be associated with an increased risk of aspiration, dysphonia, and granulation tissue formation at the operation site. We aimed to investigate the effectiveness of a novel mucosa-sparing technique based on the generation of a magnetic field within the larynx for the tailored lateralization of the ipsilateral vocal fold.

STUDY DESIGN

This is an ex vivo experimental study.

METHODS

Twenty sheep larynges that were procured from the local slaughterhouse were used as a model. For each specimen, two neodymium (Nd) disc magnets with marked poles were used to create a unilateral attractive magnetic force at the glottic level. Following insertion of the magnets, the level of vocal fold lateralization was assessed under an operating microscope. The results were analyzed for their statistical significance.

RESULTS

Before the procedure, the mean value of the glottic openings of all the specimens was 4.985 mm. The postprocedure mean value was 5.640 mm. The mean amount of increase in the glottic openings after the procedure was 0.655 mm. This change was found to be statistically significant (P < 0.05).

CONCLUSIONS

A statistically significant increase in the cross-sectional area of the glottic region could be achieved. The mucosal integrity of the laryngeal airway was also preserved. The idea of "magnetic control of the glottic airway" is a novel concept but seems to be a promising option.

[Reinnervation and neurostimulation of the larynx]

Dynamic rehabilitation of vocal fold paralysis (VFP) should receive more emphasis in the future. In unilateral immobility with signs of atrophy and wide glottal gap, non-selective reinnervation with ansa cervicalis may become an alternative to augmentation and thyroplasty. For bilateral VFP progress has been made in the concepts of selective reinnervation and neurostimulation (pacing). These new therapies have the potential to restore near normal respiration-without compromising the voice quality-and may contribute to the development of larynx transplantation surgery.