Laryngeal Reinnervation: The History and Where We Stand Now.

Injury to the recurrent laryngeal nerve (RLN) can result in impairment of all three laryngeal functions. The RLN is capable of regeneration, but laryngeal functions in cases of severe injury remain impaired. This permanent impairment is caused by either incomplete regeneration and/or occurrence of laryngeal synkinesis. Laryngeal reinnervation can be approached either nonselectively, focusing on nerve reconstruction, or selectively, focusing on separate target muscle reinnervation. Nonselective reinnervation comprises anastomosis to the mainstem of the RLN leading to reinnervation of both abductor and adductor muscle groups (nerve-based reconstruction). In selective reinnervation, abductor and/or adductor muscles are separately reinnervated (function-based reconstruction). A review of laryngeal reinnervation techniques, results in animal models, and the results achieved in patients are given. The clinical implications of reinnervation in unilateral as opposed to bilateral vocal fold paralysis are considered. For unilateral vocal fold paralysis and nonselective reinnervation, good voice results can be achieved. It has the advantage that no foreign materials need to be implanted and may also be used in a growing larynx in the case of children or adolescents. For bilateral vocal fold paralysis, good functional results, recovery of airway as well as voice, can be achieved with selective (or function-based) reinnervation

Les clefs de la réussite de la thyroplastie de type I avec implant de Montgomery® pour immobilité laryngée unilatérale de l’adulte

Dans cet article, les auteurs détaillent, au vu des données de la littérature médicale scientifique, les points techniques clefs, les erreurs à éviter, ainsi que les principaux résultats et limitations de la thyroplastie de type I avec implant de Montgomery® dans les immobilités laryngées unilatérales

Keys to successful type-1 thyroplasty with Montgomery® implant for unilateral laryngeal immobility in adults.

Based on a review of the medical literature, the authors document the key technical points and pitfalls in type I thyroplasty with Montgomery® implant, and the main results and indications in unilateral laryngeal immobility

Does the wearing of masks change voice and speech parameters?

The authors aim to review available reports on the potential effects of masks on voice and speech parameters. A literature search was conducted using MEDLINE and Google Scholar databases through July 2021. Several targeted populations, mask scenarios and methodologies were approached. The assessed voice parameters were divided into self-reported, acoustic and aerodynamic. It was observed that the wearing of a face mask has been shown to induce several changes in voice parameters: (1) self-reported-significantly increased vocal effort and fatigue, increased vocal tract discomfort and increased values of voice handicap index (VHI) were observed; (2) acoustics-increased voice intensity, altered formants frequency (F2 and F3) with no changes in fundamental frequency, increased harmonics-to-noise ratio (HNR) and increased mean spectral values in high-frequency levels (1000-8000 Hz), especially with KN95 mask; (3) aerodynamics-maximum phonatory time was assessed in only two reports, and showed no alterations. Despite the different populations, mask-type scenarios and methodologies described by each study, the results of this review outline the significant changes in voice characteristics with the use of face masks. Wearing a mask shows to increase the perception of vocal effort and an alteration of the vocal tract length and speech articulatory movements, leading to spectral sound changes, impaired communication and perception. Studies analyzing the effect of masks on voice aerodynamics are lacking. Further research is required to study the long-term effects of face masks on the potential development of voice pathology

A Systematic Review on Surgical Treatments for Sulcus Vocalis and Vocal Fold Scar.

OBJECTIVES/HYPOTHESIS: Vocal fold sulcus and scars are benign vocal fold lesions that present as a challenge to the laryngologist. A number of different surgical techniques have been proposed, aiming at restoring the lamina propria (LP), closing the glottal gap, or both. This study aimed to provide a systematic review of surgical treatment for sulcus and scar and to propose a new classification for these techniques. STUDY DESIGN: A literature search using MEDLINE and Google Scholar through August 2020. METHODS: Data on study design were retrieved and outcomes were classified as acoustic, aerodynamic, self-reported, perceptual, and stroboscopic. Methodological quality was assessed using the MINORs criteria. Each technique was classified as direct, indirect, or combined. RESULTS: Our search included 31 studies with a total of 617 patients. Direct techniques included dissection, graft interposition, or LP regeneration/scar degradation while indirect techniques aimed for glottal gap closure. Only one article performed a comparison between different types of techniques and only eight studied the five types of outcomes. No superiority of any technique was noted in our analysis. Self-reported outcomes were the most frequently improved. CONCLUSIONS: There seems to not exist a one-fits-all treatment for this clinical picture and no clear decision-making pattern. A recent trend toward sequential approaches, starting with less invasive procedures, can be observed. Laryngoscope, 132:822-830, 2022

Treatment of unilateral vocal fold paralysis with ansa cervicalis to recurrent nerve anastomosis in a young adolescent: European case report

Background Laryngeal re-innervation in paediatric unilateral vocal fold paralysis is a relatively new treatment option, of which there has been little reported experience in Europe. Methods In this European case report of a 13-year-old boy with dysphonia secondary to left-sided unilateral vocal fold paralysis after cardiac surgery, the patient underwent re-innervation using an ansa cervicalis to recurrent laryngeal nerve transfer, in combination with fat augmentation, after 12 years of nerve denervation. Perceptual analysis data, and acoustic and laryngoscopy recordings were acquired pre-operatively, and at one and two years post-operatively. Results The patient's perceptual voice quality was improved. He experienced subjective improvement and is very satisfied with the result. As expected, laryngoscopy at one and two years after surgery showed no physiological mobility of the vocal fold concerned, but improved closure during phonation was achieved. Electromyography showed evidence of re-innervation. Conclusion Laryngeal re-innervation could be considered as a treatment option for unilateral vocal fold paralysis in children and adolescents, even after a long-term delay

Neural correlates of healthy sustained vowel phonation tasks: A systematic review and meta-analysis of neuroimaging studies

Objective. This review of the methodology and results of studies involving a sustained vowel phonation tasks during functional Magnetic Resonance Imaging (fMRI) aims to contribute to the identification of brain regions involved in phonation for healthy subjects. Data sources. This review was performed using the PubMed electronic database. Review Methods. A review was conducted, according to PRISMA guidelines, between September and November 2020, using the following search term pairs: ‘fMRI and Phonation’ and ‘fMRI and Voice’. Activation likelihood estimation (ALE) analysis was performed. A qualitative analysis was also performed to specify the frequency of activation of each region, as well as the various activation clusters within a single region. Results. Seven studies were included and analyzed. Five of the seven studies were selected for the ALE meta-analysis which revealed significant convergent activation for only one cluster located in the left precentral gyrus (BA4). A qualitative review provides an overview of brain activation. Primary motor and premotor areas were the only activated areas in all studies included. Other regions previously considered to be implicated in phonation were often activated in sustained vowel phonation tasks. Additionally, areas generally associated with articulation or language also showed activation. Conclusion. Methodological recommendations are suggested to isolate the phonatory component and reduce variability between future studies. Based on the qualitative analysis, this review does not support a distinction between regions more related to phonation and regions more related to articulation. Further research is required seeking to isolate the vocal component and to improve insight into human brain network involved in phonation

The larynx ruler to measure height and profile of vocal folds: A proof of concept

Introduction: Glottic leakage during phonation is a direct consequence of unilateral vocal fold (VF) paralysis. This air leakage can be in the horizontal plane and in the vertical plane. Presently, there is no easily applicable medical device allowing noninvasive, office-based measurement of the relative vertical position of the VFs. The larynx ruler (LR) is a laser-based measuring device that could meet the previously stated need, using a flexible endoscope. This study represents a proof of concept regarding the use of the LR in assessing VF relative positions in the vertical plane. Materials and methods: One fresh male human cadaver larynx, free of neurologic and anatomic disease, was explored with the LR system through the operative channel of a flexible gastroenterology video-endoscope. The tip of the video-endoscope was located in the laryngeal vestibule. The right crico-arytenoid joint was posteriorly disarticulated. Tilting of the VF was obtained by pulling or pushing the arytenoid cartilage with a mosquito forceps fixed to the stump of the previously sectioned superior tip of the posterior crico-arytenoid muscle allowing anterior and posterior tilting of the arytenoid cartilage in order to induce an elevation or a depression of the VF process. Ten “push” and ten “pull” sessions were performed. The distance from the tip of the video-endoscope to each illuminated pixel of the laser beam was recorded. The level difference between the left and right VFs was measured for each recording. Results: Data provided by the LR were consistently in accordance with the movements applied on the VFs. The accuracy of 0.2 mm of the LR is compatible with the envisioned applications for the human larynx. Conclusion: The LR system represents a feasible technique to evaluate respective vertical position of VFs in the human larynx. Technical limitations were identified that will require improvements before experimental use on human beings.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Voice outcome indicators for unilateral vocal fold paralysis surgery: A survey among surgeons

INTRODUCTION: Standardization of voice outcomes indicators (VOIs) is an important issue when it comes to evaluating and comparing surgical treatments for Unilateral Vocal Fold Paralysis (UVFP). In a recent review, 11 VOIs were found to represent 80% of the VOIs cited in the literature. A survey was launched among the European laryngologists to acquire surgeons' opinions on the above mentioned preselected VOIs. MATERIAL AND METHOD: The electronic survey took place between November and December 2016. Three general questions were asked about surgeon's practice setting(s) and experience. The eleven next questions concerned (a) surgeon's VOIs preference and (b) their estimates of post-operative target values, they would consider being satisfactory. RESULTS: The response rate was 16% (50 surveys). The majority of responders worked in tertiary hospitals (50%), had 15 years of experience with UVFP and performed on average 20 UVFP related procedures a year. The VOIs that were favored by the responding surgeons were, in decreasing order of importance, Voice handicap Index (VHI-30), Maximum Phonation Time (MPT), GRBAS-I, Mean Airflow Rate (MeAF), Jitter and Shimmer. There was an excellent consensus on post-operative VOI target values between survey's results and the literature data, except for three VOIs that showed somewhat divergent tendencies (absolute VHI-30, Jitter and Shimmer). CONCLUSIONS: Three VOIs are favored by surgeons: VHI-30, MPT and GRBAS-I. Jitter and Shimmer, although very frequently reported and statistically valid in the literature, come last concerning surgeon's choice as VOI for UVFP treatment assessment

Accuracy of Thyroid Cartilage Fenestration During Montgomery Medialization Thyroplasty

Introduction. Accuracy of thyroid cartilage fenestration during Montgomery thyroplasty (MTIS) is considered a key success factor. The primary aim of the study was to retrospectively evaluate the accuracy of fenestration. Furthermore, recent publications indicate a possible discrepancy in MTIS voice outcomes related to gender. The secondary aim of the study was to investigate whether the fenestration accuracy could explain this discrepancy.Material and Method. Study was performed by virtually drawing the fenestration on a 3D CT scan as proposed by the MTIS's instructions for use (the "expected window" (EW)), and comparing it to the actually realized fenestration (the "realized window "(RW)). Four position variables, (a) surface overlap (%), (b) the distances between RW and EW centers (mm), (c) the angle between RW and EW (), and (d) the orientation of RW's center, were studied and compared to MPT (seconds) and VHI-30 scores outcomes. A descriptive statistical analysis and comparison between males and females were performed using a Mann-Whitney U test. Linear regression and multivariate analysis were also performed.Results. The median overlapping surface was 58.8 % [34.6; 75.4]. The median radius was 3.2 mm [1.7; 4.1]. The median angle was 16 [6.8; 21.2]. Results show no significant differences of overlapping surface percentage, distance, or angle by gender. Data show no correlation between voice outcome and percentage overlap, distance, or angle. However, data show better outcomes when fenestration was located in the infero-anterior orientation. All patients of this orientation were males.Conclusions. Data provided by this study advocate a maximal infero-anterior positioning of the window during MTIS. This position is more difficult to obtain in female patients.Otorhinolaryngolog