Injection laryngoplasty with hyaluronic acid for glottal insufficiency in unilateral vocal fold paralysis: a systematic review of the literature.

BACKGROUND: Glottal insufficiency, mostly caused by unilateral vocal fold paralysis (UVFP) or vocal fold atrophy can be treated by injection laryngoplasty (IL). Materials such as hyaluronic acid (HA) gels are now widely available and used to improve voice quality. Various durability and effects of HA injection laryngoplasties have been reported. The aim of this study is to provide a systematic review of the literature for the use of HA in injection laryngoplasties. METHODS: A systematic literature search was conducted in PubMed and Cochrane Libraries. Three reviewers assessed original research studies concerning vocal fold augmentation with HA for eligibility. English written full-text human studies from 2000 to 2020 with EBM level 1b-2 were included. In vitro studies, animal studies, case reports, case-control studies, correspondence and review articles, and articles with other injection materials were excluded. Demographical data, indication, type of HA, evaluation methods, follow-up, durability of implanted material and complications were assessed. RESULTS: A total number of 311 articles were found in PubMed and Cochrane Library, 13 studies were eligible for final analysis with 1063 patients, mean age of patients was 58.7 years. Main indication for HA IL was unilateral vocal fold paralysis, evaluation methods were subjective-VHI (Voice Handicap Index) questionnaire and objective-acoustic and aerodynamic measurements, mean time of follow-up was 5.9 months. Large-particle HA gels were more favorable for longer durability than small-particle HA, reported time of resorption of HA gels ranges between 6 and 12 months, and complication rate was low. CONCLUSION: Hyaluronic acid injection laryngoplasty increases voice quality, improves results of voice therapy, and can be recommended as overlap treatment before permanent medialization surgery. Compared to other injected materials, HA seems to have more favorable effect on vibratory functions of the vocal folds and thus on the voice quality parameters.

Clinical study of injectable collagen scaffold with autologous fat cells for repair of severe vocal fold injury.

Cell retention and survival after transplantation remains a major problem for long-term efficiency in therapy of severe vocal fold injury with autologous cells. In this study, injectable collagen scaffold was used to deliver autologous fat cells (AFCs) for repairing of severe vocal fold injury. We found injectable collagen scaffold could enhance the retention and survival of green fluorescent protein (GFP) labeled fat cells in the transplantation sites in rats. Based on these data, a randomized controlled clinical trial was conducted to evaluate the safety and efficiency of transplantation of collagen scaffold with AFCs for severe vocal fold injury. Ten patients with vocal fold paralysis were randomly assigned to control (AFCs only) and intervention (AFCs + collagen) groups. AFCs with or without collagen scaffold were injected into vocal folds of patients under general anesthesia, respectively. The safety and efficacy were regularly assessed during 24 months post-surgery. No obvious complications occurred in all patients during the follow-up. The collagen scaffold maintained the stability of implants after injection and reconstructed the vocal fold structure. The improvement of voice quality of patients was observed through voice quality evaluation with the voice handicap index (VHI) questionnaire, as well as acoustic analysis of maximum phonation time, jitter, and shimmer. The VHI score of patients in AFCs + collagen group improved significantly than those in AFCs group at 6, 12 and 24 months post-surgery. It demonstrates the injectable collagen scaffold is safe and efficient for delivering AFCs for vocal fold injury.

Effect of Fascia Implantation and Controlled Release of Basic Fibroblast Growth Factor for Muscle Atrophy in Rat Laryngeal Paralysis.

OBJECTIVE: To improve lateral thyroarytenoid (TA) muscle atrophy after laryngeal paralysis, reconstruction of the vascular network of the atrophied muscle is necessary. We therefore evaluated whether the controlled release of basic fibroblast growth factor (bFGF) with autologous fascia implantation could affect vascular reconstruction in the lateral TA muscle. STUDY DESIGN: Animal experiment. SETTING: Laboratory. METHODS: Unilateral laryngeal paralysis was induced in 20 rats. The rats were implanted with autologous fascia and a gelatin hydrogel sheet with or without 1 µg of bFGF (fascia and bFGF + fascia groups; n = 5 each) and with only a gelatin hydrogel sheet with bFGF (bFGF group: n = 5). Another group remained untreated (n = 5) at 4 months after paralysis. At 3 months since transplantation, intra- and intergroup comparisons of the muscle volumes and total area of blood vessels in the lateral TA muscle were performed. RESULTS: When compared with the untreated group, the bFGF + fascia group showed a significant increase in muscle volume (P =.0008) and vascular area (P =.0002) in the lateral TA muscle, whereas the other 2 treated groups demonstrated an insufficient effect. CONCLUSION: bFGF + fascia implantation showed histologic improvement in severe laryngeal paralysis. We demonstrated that the decrease in lateral TA muscle mass after paralysis might be countered by the reconstruction of the vascular network. Our findings indicate that hypovascular and denervated areas of the laryngeal muscle can be regenerated by the implantation of growth factors and scaffolds with surgical stress. LEVEL OF EVIDENCE: 5.

Stridor Due to Cranial Nerve X Palsy Progressing to Polyneuropathy in a Teenager With COVID-19.

The neurologic manifestations of coronavirus disease 2019 (COVID-19) are wide-ranging, including various cranial neuropathies, beyond anosmia and dysgeusia, the exact neuropathological mechanism of which are yet unknown. Acute cranial nerve (CN) X neuritis with vocal cord paralysis has not been reported in COVID-19 and is a rare presentation of neuropathy in general. A girl aged 14 years was admitted with stridor. She was diagnosed with symptomatic COVID-19 8 days before. By presentation, fever had resolved, but she had developed stridor; sore throat with dysphagia; chest, shoulder, and back pain; and generalized weakness. Neurologic examination and laryngoscopy were consistent with isolated left CN X palsy. Steroids were started, but neurologic disease progressed with subjective pain, right lower face numbness, and eye fatigability. Respiratory distress increased, and she was intubated for airway protection. MRI revealed abnormal enhancement of CNs III, V, XII, and X. Cerebrospinal fluid studies were normal. Nasopharyngeal severe acute respiratory syndrome coronavirus 2 polymerase chain reaction test result was positive. She was treated with intravenous immunoglobulin, a total of 2 g/kg, and steroids were continued. She made a full neurologic recovery and was discharged after 9 days of hospitalization. This is a case of a teenager who presented with an acute, life-threatening CN X palsy and development of a progressive polyneuropathy in the setting of COVID-19. Although there was concern for Guillain-Barre syndrome, a definitive diagnosis could not be made, and the unusual features of this case, including presentation with stridor and predominate CN involvement seem to indicate a separate symptomatic COVID-19-associated polyneuritis.

Objective evaluation of biomaterial effects after injection laryngoplasty - Introduction of artificial intelligence-based ultrasonic image analysis.

OBJECTIVE: Hyaluronic acid (HA) can be degraded over time. However, persistence of the effects after injection laryngoplasty (IL) for unilateral vocal fold paralysis (UVFP), longer than expected from HA longevity, has been observed. The purpose of the study was to develop a methodology with clinical utility for objective evaluation of the temporal change in HA volume after IL using artificial intelligence (AI)-based ultrasonic assessment. DESIGN, SETTING AND PARTICIPANTS: Imaging phantoms simulating injected HA were built in different volumes for designing the algorithm for machine learning. Subsequently, five adult patients who had undergone IL with HA for UVFP were recruited for clinical evaluation. MAIN OUTCOME MEASURES: Estimated volumes were evaluated for injected HA by the automatic algorithm as well as voice outcomes at 2 weeks, and 2 and 6 months after IL. RESULTS: On imaging phantoms, contours on each frame were described well by the algorithm and the volume could be estimated accordingly. The error rates were 0%-9.2%. Moreover, the resultant contours of the HA area were captured in detail for all participants. The estimated volume decreased to an average of 65.76% remaining at 2 months and to a minimal amount at 6 months while glottal closure remained improved. CONCLUSION: The volume change of the injected HA over time for an individual was estimated non-invasively by AI-based ultrasonic image analysis. The prolonged effect after treatment, longer than HA longevity, was demonstrated objectively for the first time. The information is beneficial to achieve optimal cost-effectiveness of IL and improve the life quality of the patients.

Additional Injection Laryngoplasty for Patients With Unilateral Vocal Fold Paralysis.

OBJECTIVES: In case of insufficient voice improvement after injection laryngoplasty (IL), additional IL will be one of the next option of treatments. However, little is known about the voice outcomes regarding an additional IL. STUDY DESIGN: Retrospective comparative study in single institution. METHODS: We enrolled the patients of unilateral vocal fold paralysis (UVFP), who received IL (N = 76) twice because of insufficient voice improvement. The etiologies of UVFP were related with thoracic and esophageal surgery (51.3%), neck surgery (30.3%), skull base surgery (7.9%), or unknown (10.5%). The subjective and objective voice parameters were collected before and after (mean: 5.3 months) each IL. RESULTS: Aspiration, maximum phonation time (MPT), jitter percentage, shimmer percentage, and noise to harmonic ratio (NHR) were significantly improved after both the first and second rounds of IL (P < .05). Voice handicap index (VHI)-30 was also significantly improved after both the first and second rounds of IL (P < .001). Regarding GRBAS score, overall grade of dysphonia (G), roughness (R), and breathiness (B) were significantly improved after the first IL, but only G and R after the second IL (P < .05). In comparison between postprocedural voice parameters of the first and second ILs, MPT was significantly improved from 5.5 ± 3.5 seconds to 7.3 ± 7.5 seconds (P = .001). Grade of dysphonia (1.9 ± 0.8) and breathiness (1.7 ± 0.9) of post-first IL were significantly (P < .001) improved to those of post-second IL (1.3 ± 0.7 and 1.2 ± 0.7, respectively). VHI-30 of post-first IL (72.0 ± 20) was significantly improved (P < .001) to those of the second IL (57.2 ± 23.7). CONCLUSIONS: In selected patients, additional IL could provide further improvement of voice in patient who had unsatisfactory voice results despite of initial IL. LEVEL OF EVIDENCE: 4 Laryngoscope, 2020.

Stroboscopic assessment of unilateral vocal fold paralysis: a systematic review.

PURPOSE: To review the relevant basic stroboscopic evaluations in unilateral vocal fold paralysis (UVFP). Our aim was twofold: (1) to determine the frequency of use of stroboscopic parameters in outcome evaluation after surgical treatment of UVFP using a Pareto diagram; and (2) to select the most relevant parameters in terms of a significant difference between pre- and post-surgical intervention for UVFP. METHODS: A systematic review in PUBMED includes studies on stroboscopic evaluation in combination with UVFP and surgical treatment. The review was limited to English studies published between 1990 and March 2018. The most frequently used stroboscopic parameters were identified using a Pareto diagram. Then, 'the percentage of significance' for the most frequently stroboscopic parameters was identified by comparing the number of studies that showed a statistically significant change in pre- and post-treatment results with the total number of studies using the same parameters. RESULTS: Seven stroboscopic parameters were nominated using the Pareto diagram. In decreasing order of citation frequency, periodicity, edge bowing, mucosal wave, glottic gap, position of vocal fold, amplitude, and symmetry have respective percentages of significance of 87.5%, 83.3%, 77.7%, 64.5%, 60%, 57.1%, and 50%. Five pertinent scales were selected for the most frequent and significant stroboscopic parameters. CONCLUSIONS: The results indicate that periodicity, edge bowing, mucosal wave, glottic gap, and position of vocal fold represent the five most frequently used and relevant stroboscopic parameters in UVFP evaluation. The current review outlines a proposal scale of these stroboscopic parameters. PROSPERO REGISTRATION NUMBER: CRD42019126786.

Voice aerodynamics following office-based hyaluronate injection laryngoplasty.

OBJECTIVES: Neuromuscular control, glottal conformation and aerodynamics are the major factors affecting voice performance. We aimed to characterise the degree to which voice improvements following office-based intracordal hyaluronate injection laryngoplasty (HIL) depend on changes in voice aerodynamics in patients with unilateral vocal fold paralysis (UVFP), by assessing the correlations between these parameters. DESIGN: Prospective case series. SETTING: Otolaryngology Clinics in a Medical Center. PARTICIPANTS: Patients with UVFP within 6 months of their first outpatient visit who received single HIL. MAIN OUTCOME MEASURES: Videolaryngostroboscopy, aerodynamics and laboratory voice analysis were evaluated at baseline and 1 month after HIL. Quantitative laryngeal electromyography was evaluated at baseline to confirm UVFP. RESULTS: Seventy-five newly diagnosed patients with UVFP were analysed. The normalised glottal gap area (NGGA) decreased (P < 0.001) (Cohen's dz  = 0.94) and all aerodynamic parameters improved (all P < 0.05) (Cohen's dz  = 0.38-1.02) following HIL. Patients undergoing thoracic surgery had more profound aerodynamic impairments both before and after HIL. After adjusting for improvements in NGGA, the improvement in aerodynamics was correlated with voice improvement and most notably with maximum phonation time and jitter/shimmer. CONCLUSIONS: Hyaluronate injection laryngoplasty improved glottal conformation, aerodynamics and voice, highlighting the benefit of early HIL intervention for patients with UVFP. Patients with UVFP caused by thoracic surgery continued to have poorer aerodynamics post-HIL, indicating the importance of speech therapy in these patients.

In-Office Laryngology Injections.

The ability to perform in-office vocal fold injections has been greatly enhanced by advances in videolaryngoscopy technology. With improved optics and thin, channeled flexible laryngoscopes, in-office laryngeal injections have expanded from vocal fold augmentation for glottic insufficiency, vocal cold immobility, and botulinum toxin injections for spasmodic dysphonia, to vocal fold steroid injections for benign vocal fold lesions and scars and various injections for neurogenic cough. Efficacy, approaches, post-procedure management, and common complications of in-office laryngeal injections are outlined and supporting evidence discussed.

[Effect of cricothyroid and thyroarytenoid muscle botulinum toxin injection on patients with dyspnea caused by bilateral recurrent laryngeal nerve paresis].

Objective: To discuss the clinical effect of small dose of botulinum toxin injection in cricothyroid muscle and thyroarytenoid muscle on patients with incomplete bilateral recurrent laryngeal nerve paresis. Methods: Six patients were selected with Ⅰor Ⅱ or Ⅲ degree of dyspnea diagnosed as bilateral recurrent laryngeal nerve injury by laryngeal electromyography, and small dose of botulinum toxin injection was performed in cricothyroid muscle and thyroarytenoid muscle as a treatment. Degree of dyspnea was assessed one month before and after the treatment, and the stroboscopic laryngoscope results, acoustic parameters and CT image of the patients were collected in the 6 patients. The relevant parameters were also collected one month before and after treatment, including the degree of dyspnea, stroboscopic laryngoscope results, acoustic parameters and CT image of the patients. The angle between bilateral vocal cords in stroboscopy at full inspiratory was calculated, acoustic parameters (F0, jitter, shimmer) were analysed, and vocal length, width and the vocal region were measured. Then, the paired t test was performed for statistical analysis between before and after one month injection, the one way analysis of variance was performed among vocal parameters in CT image. Result: Botulinum toxin injection was successfully completed in the 6 patients, followed without any serious complications. The degree of dyspnea was alleviated to some extent after treatment in all 6 patients; the angle between bilateral vocal cords at the end of a deep inspiration was significantly increased (t=2.44, P<0.05) after the treatment. The changes of F0 and jitter between before and after treatment were not statistically significant (t=0.72, t=1.42, P>0.05). Shimmer was significantly decreased after treatment (t=2.61, P<0.05). Vocal fold length, width and vocal region increased with F0, there was a statistically significant difference between different F0 before injection, and there was no statistically significant difference between different F0 after injection. The follow-up time was respectively seven months, 1 year, 1 year, 18 months, 22 months and 2 years respectively. Conclusion: Small dose of botulinum toxin injection in bilateral cricothyroid muscles and thyroarytenoid muscles can relieve the dyspnea caused by bilateral vocal cords paresis to some extent, accompanied without serious complications, despite the sound quality was slightly worse.

Changes in Peak Airflow Measurement During Maximal Cough After Vocal Fold Augmentation in Patients With Glottic Insufficiency.

Importance: Compromised cough effectiveness is correlated with dysphagia and aspiration. Glottic insufficiency likely yields decreased cough strength and effectiveness. Although vocal fold augmentation favorably affects voice and likely improves cough strength, few data exist to support this hypothesis. Objective: To assess whether vocal fold augmentation improves peak airflow measurements during maximal-effort cough following augmentation. Design, Setting, and Participants: This case series study was conducted in a tertiary, academic laryngology clinic. Participants included 14 consecutive individuals with glottic insufficiency due to vocal fold paralysis, which was diagnosed via videostrobolaryngoscopy as a component of routine clinical examination. All participants who chose to proceed with augmentation were considered for the study whether office-based or operative augmentation was planned. Postaugmentation data were collected only at the first follow-up visit, which was targeted for 14 days after augmentation but varied on the basis of participant availability. Data were collected from June 5, 2014, to October 1, 2015. Data analysis took place between October 2, 2015, and March 3, 2017. Main Outcomes and Measures: Peak airflow during maximal volitional cough was quantified before and after vocal fold augmentation. Participants performed maximal coughs, and peak expiratory flow during the maximal cough was captured according to American Thoracic Society guidelines. Results: Among the 14 participants (7 men and 7 women), the mean (SD) age was 62 (18) years. Three types of injectable material were used for vocal fold augmentation: carboxymethylcellulose in 5 patients, hyaluronic acid in 5, and calcium hydroxylapatite in 4. Following augmentation, cough strength increased in 11 participants and decreased cough strength was observed in 3. Peak airflow measurements during maximal cough varied from a decrease of 40 L/min to an increase of 150 L/min following augmentation. When preaugmentation and postaugmentation peak airflow measurements were compared, the median improvement was 50 L/min (95% CI, 10-75 L/min; P = .01). Immediate peak airflow measurements during cough collected within 30 minutes of augmentation varied when compared with measurements collected at follow-up (103-380 vs 160-390 L/min). Conclusions and Relevance: Peak airflow during maximal cough may improve with vocal fold augmentation. Additional assessment and measurements are needed to further delineate which patients will benefit most regarding their cough from vocal fold augmentation.

Two Cases of Neurolymphomatosis with Fatal Bilateral Vocal Cord Paralysis that were Diagnosed with 18F-fluorodeoxyglucose Positron Emission Tomography (FDG PET)/CT.

Neurolymphomatosis is a rare entity defined as nerve infiltration by neurotropic abnormal lymphocytes which can lead to the development of neuropathy, with typical presentations including pain, hypoesthesia, paresthesis and palsy. We herein report two cases where critical bilateral vocal cord paralysis due to neurolymphomatosis in recurrent nerves occurred in refractory Burkitt lymphoma and adult T-cell lymphoma patients. High-dose methotrexate and intrathecal chemotherapy injection for the nervous lesions were ineffective, and the patients died. Neurolymphomatosis of the recurrent nerve is an emergent and difficult complication and should be suspected when sudden onset of aphasia, hoarseness or shortness of breath is found in refractory lymphoma patients.

[The clinical features and drug therapy of unilateral idiopathic vocal fold paralysis].

OBJECTIVE: To investigate the clinical features and medication of unilateral idiopathic vocal fold paralysis. METHOD: Thirty-nine of medical treated patients with unilateral idiopathic vocal fold paralysis were retrospectively studied, and relevant literatures were reviewed. RESULT: After 4 to 19 days of medical therapy, 9 patients were cured, the vocal fold movement of 18 sufferers were improved, and 12 pantients were not healed. CONCLUSION: Unilateral idiopathic vocal fold paralysis is common, and the treatment efficacy of medicine is almost the same with others. Unilateral idiopathic vocal fold paralysis is a disease with spontaneous recovery, which should be followed up.

In-Office Hyaluronate Injection Laryngoplasty as Palliative Treatment for Unilateral Vocal Fold Paralysis.

BACKGROUND: Voice and swallowing impairments can impact on both quality of life and survival. Unilateral vocal fold paralysis (UVFP) as a result of distant metastasis can cause breathy voice and aspiration. The purpose of this study is to develop and evaluate a less invasive and effective alternative therapy for UVFP. METHODS: This was a retrospective review of prospectively enrolled patients at a tertiary referral center in Taiwan. Among a cohort of 177 patients who received intracordal hyaluronate injections, 2 had UVFP from distant metastasis and met the inclusion criteria. Vocal cord motion was recorded by videostroboscopy, and the normalized glottal gap area was measured. Voice quality, defined by speech language pathologists, and swallowing status were compared, and immediate complications after the injection were investigated. RESULTS: Two patients with UVFP with M1 lesions (both lung) accepted the procedure. The glottal gap area was significantly improved 1 month after in-office hyaluronate injection. Voice quality and aspiration were also improved. No immediate complications were noted in either patient. CONCLUSIONS: In-office intracordal hyaluronate injection is a safe and effective treatment for UVFP, providing a palliative method to help maintain the patient's voice and quality of life.

Outpatient-based injection laryngoplasty for the management of unilateral vocal fold paralysis - clinical outcomes from a UK centre.

OBJECTIVE: To assess voice outcomes in patients undergoing vocal fold injection (VFI) augmentation laryngoplasty in a clinic-based setting. METHODS: A prospective study of patients with unilateral vocal cord palsy undergoing Radiesse(®) vocal cord augmentation. We used the ten-item voice handicap index (VHI-10) as a postal survey before and after the intervention. RESULTS: A total of 43 patients were referred to our ENT clinic from June 2011 to October 2014 with unilateral vocal cord palsy. The majority were referred from the oncology department with mediastinal tumours. Fifteen patients died of malignant disease. Twenty-one patients responded to our survey. VHI-10 scores were analysed using one-way analysis of variance (anova), and the results suggest a sustained improvement before and after the intervention (pre-injection versus 3 months post-injection P < 0.01; pre-injection versus 6 months post-injection P < 0.033). CONCLUSION: This is the largest case series of patients who had a local anaesthetic vocal cord injection with calcium hydroxylapaptite using the trans-thyrohyoid approach. Early data would suggest that the results are similar to injections performed under general anaesthesia when performed by an experienced laryngologist. VFI in a clinic-based (awake) setting has the distinct advantage of providing instant feedback of vocal fold closure and voice outcome during the procedure, avoiding general anaesthesia with its inherent risks and cost and also the limitations of difficult exposure.

Cricothyroid Muscle Botulinum Toxin Injection to Improve Airway for Bilateral Recurrent Laryngeal Nerve Paralysis, A Case Series.

Bilateral vocal fold paralysis most commonly results from iatrogenic trauma to the recurrent laryngeal nerve during surgical procedures in the anterior neck. Patients may require tracheostomy because of acute or gradual onset of dyspnea and airway compromise. The intralaryngeal injection of Botox has been considered as a possible therapy for these airway symptoms of bilateral vocal fold paralysis. Chronic unopposed activity of intact cricothyroid muscles could potentially result in gradual medialization of the vocal folds in patients with bilateral recurrent laryngeal nerve paralysis. This case series describes three patients who successfully underwent injections of botulinum toxin into the bilateral cricothyroid muscles to offer sustained relief of dyspnea resulting from bilateral vocal fold paralysis.

Laringoplastía de inyección con ácido hialurónico, experiencia del Hospital Clínico de la Pontificia Universidad Católica de Chile / Laryngoplasty injection with hyaluronic acid, Hospital Clinico de la Pontificia Universidad Catolica de Chile experience

Introducción: El manejo inicial de la parálisis cordal unilateral incluye la observación en espera de la recuperación de la movilidad o la compensación, terapia fonoaudiológica o inyección de medialización temporal para llevar la cuerda a una posición más favorable para el cierre glótico. Este procedimiento puede realizarse en pabellón, o vía percutánea en paciente despierto. Existen varias opciones, siendo el ácido hialurónico (Restylane®) uno de los más usados. Objetivo: Revisar la experiencia pionera en el país en la inyección de medialización de cuerda vocal con ácido hialurónico en el manejo de la parálisis cordal unilateral. Material y método: Estudio retrospectivo, que incluyó a 15 pacientes con insuficiencia glótica a los que se les realizó una inyección percutánea con ácido hialurónico. Se evaluó la calidad de la voz pre y posprocedimiento (VRQOL), tolerancia al procedimiento y complicaciones. Resultados: El 100% de los pacientes mostró cambios significativos en el VRQOL, con un cambio promedio pre y post de 37%. El procedimiento fue bien tolerado en el 93%. No se produjeron incidentes durante la inyección ni tampoco posteriores. Conclusión: La inyección de medialización es un procedimiento bien tolerado, seguro y sencillo, que permite mejoras significativas en la calidad vocal. El ácido hialurónico es seguro y eficaz para la inyección de medialización.

Introduction: Initial treatment options for unilateral vocal fold paralysis include observation for spontaneous return of function or compensation, voice therapy to stimulate recovery of motion or function, or temporary vocal fold injection medialization to improve glottic closure. Temporary injection medialization can be performed under general anesthesia or in the awake-patient setting with local anesthesia. There are different options of temporary injection materials, being hyaluronic acid (Restylane®) one of the most popular. Aim: To review our pioneer experience in Chilewith the use of temporary vocal fold injection with hyaluronic acid in the initial management of unilateral vocal fold paralysis. Material and method: Retrospective study involving 15 patients with glottic insufficiency, who underwent percutaneous vocal fold injection medialization with hyaluronic acid. Pre and post procedure quality of voice (VRQOL), tolerance to the procedure, and complications were evaluated. Results: All patients showed significant changes in VRQOL, with a 37% average improvement. The procedure was well tolerated in 93%. No incidents occurred during injection orlater. Conclusions: The temporary vocal fold injection medialization is a well-tolerated, safe and simple procedure that allows significant short-term improvements in vocal quality of patients. Hyaluronic acid is a safe and effective material for temporary vocal foldinjection medialization.