The weepy cry - short neural signal bursts in intraoperative neuromonitoring.

PURPOSE: This study aimed to establish an in-vitro alternative to existing in-vivo systems to analyze nerve dysfunction using continuous neuromonitoring (C-IONM). METHODS: Three hundred sixty-three recurrent laryngeal nerves (RLN) (N(pigs) = 304, N(cattle) = 59) from food industry cadavers were exposed by microsurgical dissection following euthanasia. After rinsing with Ringer's lactate, they were tempered at 22 °C. Signal evaluation using C-IONM was performed for 10 min at 2 min intervals, and traction forces of up to 2N were applied for a median time of 60 s. Based on their post-traumatic electrophysiological response, RLNs were classified into four groups: Group A: Amplitude ≥ 100%, Group B: loss of function (LOS) 0-25%, Group C: ≥ 25-50%, and Group D: > 50%. RESULTS: A viable in-vitro neuromonitoring system was established. The median post-traumatic amplitudes were 112%, 88%, 59%, and 9% in groups A, B, C, and D, respectively. A time-dependent further dynamic LOS was observed during the 10 min after cessation of strain. Surprisingly, following initial post-traumatic hyperconductivity, complete LOS occurred in up to 20% of the nerves in group A. The critical threshold for triggering LOS was 2N in all four groups, resulting in immediate paralysis of up to 51.4% of the nerves studied. CONCLUSION: Consistent with in-vivo studies, RLN exhibit significant intrinsic electrophysiological variability in response to tensile forces. Moreover, nerve damage progresses even after the complete cessation of strain. Up to 20% of nerves with transiently increased post-traumatic amplitudes above 100% developed complete LOS, which we termed the "weepy cry." This time-delayed response must be considered during the interpretation of C-IONM signals.

Laryngeal mask airway combined with bronchial blocker achieved 1-lung ventilation in a patient with bilateral vocal cord paralysis: A case report.

INTRODUCTION: One-lung ventilation (OLV) is a commonly used technique to facilitate surgical visualization during thoracic surgical procedures. Double-lumen endotracheal tubes and one-lumen tracheal tube combined with bronchial blocker might lead to intubation-related laryngeal injury. PATIENT CONCERNS: In the perioperative period, how to avoid further damage to the vocal cord while achieving OLV during operation is challenging work. DIAGNOSIS: She was diagnosed with systemic lupus erythematosus, bilateral vocal cord paralysis, and lung tumor. INTERVENTIONS: We used a combination of a laryngeal mask airway with bronchial blocker to avoid further damage to the vocal cord when achieving OLV. OUTCOMES: At 1-month follow-up, she had fully recovered without obvious abnormalities. CONCLUSION: When OLV was required for patients with bilateral vocal cord paralysis, a combination of a laryngeal mask airway with bronchial blocker was considered a better choice.

The Long Term Results of Hyaluronic Acid/Dextranomer Injection Laryngoplasty in Unilateral Vocal Fold Paralysis.

OBJECTIVE: This study was conducted to present the long-term functional outcomes of injection laryngoplasty (IL) with hyaluronic acid/dextranomer (HA/D) in unilateral vocal fold paralysis (UVFP). METHODS: A total of 40 patients who underwent HA/D injection for UVFP were enrolled. The acoustic analysis of the voice was evaluated with jitter percentage, shimmer percentage, maximum phonation time, harmonics-to-noise ratio, and fundamental frequency. The psychosocial effect of the voice was determined using the Voice Handicap Index-10. Fiberoptic endoscopic evaluation of swallowing was performed and 2 scales were used for quantification: a modified penetration-aspiration scale and a dysphagia score. All measurements were performed at preoperative day and postoperative months 1, 6, and 24. RESULTS: A statistically significant improvement was observed for all of the evaluated parameters except the maximum phonation time for postoperative months 1, 6, and 24 (P < .05). In the evaluation of the maximum phonation time, although there was a significant improvement for the postoperative months 1 and 6, no significant difference was observed between the postoperative 24th month and the preoperative value. CONCLUSIONS: HA/D injection laryngoplasty is an effective method both in the short- and long-term to improve voice and swallowing functions in patients with UVFP.

Acoustics and aerodynamic effects following glottal and infraglottal medialization in an excised larynx model.

OBJECTIVE: This study aimed to investigate the impact of the implant's vertical location during Type 1 Thyroplasty (T1T) on acoustics and glottal aerodynamics using excised canine larynx model, providing insights into the optimal technique for treating unilateral vocal fold paralysis (UVFP). METHODS: Measurements were conducted in six excised canine larynges using Silastic implants. Two implant locations, glottal and infraglottal, were tested for each larynx at low and high subglottal pressure levels. Acoustic and intraglottal flow velocity field measurements were taken to assess vocal efficiency (VE), cepstral peak prominence (CPP), and the development of intraglottal vortices. RESULTS: The results indicated that the implant's vertical location significantly influenced vocal efficiency (p = 0.045), with the infraglottal implant generally yielding higher VE values. The effect on CPP was not statistically significant (p = 0.234). Intraglottal velocity field measurements demonstrated larger glottal divergence angles and stronger vortices with the infraglottal implant. CONCLUSION: The findings suggest that medializing the paralyzed fold at the infraglottal level rather than the glottal level can lead to improved vocal efficiency. The observed larger divergence angles and stronger intraglottal vortices with infraglottal medialization may enhance voice outcomes in UVFP patients. These findings have important implications for optimizing T1T procedures and improving voice quality in individuals with UVFP. Further research is warranted to validate these results in clinical settings.

An Integrated Experimental-Computational Study of Vocal Fold Vibration in Type I Thyroplasty.

Subject-specific computational modeling of vocal fold (VF) vibration was integrated with an ex vivo animal experiment of type 1 thyroplasty to study the effect of the implant on the vocal fold vibration. In the experiment, a rabbit larynx was used to simulate type 1 thyroplasty, where one side of the vocal fold was medialized with a trans-muscular suture while the other side was medialized with a silastic implant. Vocal fold vibration was then achieved by flowing air through the larynx and was filmed with a high-speed camera. The three-dimensional computational model was built upon the pre-operative scan of the laryngeal anatomy. This subject-specific model was used to simulate the vocal fold medialization and then the fluid-structure interaction (FSI) of the vocal fold. Model validation was done by comparing the vocal fold displacement with postoperative scan (for medialization), and by comparing the vibratory characteristics with the high-speed images (for vibration). These comparisons showed the computational model successfully captured the effect of the implant and thus has the potential for presurgical planning.

Voice outcome in medialisation thyroplasty with and without arytenoid adduction: a prospective comparison using intraoperative voice measurements.

PURPOSE: Arytenoid adduction as an addition to medialisation thyroplasty is highly advocated by some surgeons in selected cases but deemed less necessary by others in patients with unilateral vocal fold paralysis. This study aims to evaluate the additional benefits on voice outcome of arytenoid adduction in patients with unilateral vocal fold paralysis undergoing medialisation thyroplasty using intra-operative voice measurements. DESIGN/METHODS: A prospective study was conducted. Voice audio recordings were obtained at 4 moments; 1. direct prior to the start of surgery, 2. during surgery after medialisation thyroplasty, 3. during surgery after medialisation and arytenoid adduction, 3 months postoperative. At these same timepoints patients rated their own voice on a numeric rating scale between 0 and 10. The blinded recordings were rated by consensus in a team of experienced listeners, using the Grade of the GRBAS scale. Furthermore, the Voice Handicap Index was administered before and at 3 months after surgery. RESULTS: Ten patients who underwent medialisation and arytenoid adduction at our tertiary referral hospital between 2021 and 2022, were included. One patient was excluded after surgery. The intraoperative measurements showed a Grade score of 1.4 preoperatively, improving to 1.2 after medialisation, 1.2 after medialisation and arytenoid adduction, and further improving to 0.4 at 3 months postoperative, which was a not statistically significant improvement (p = 0.2). The intraoperative subjective numeric rating scale showed a statistically significant improvement from 3.9 preoperatively, to 6.1 after medialisation, 7.1 after medialisation and arytenoid adduction and a 7.6 at 3 months postoperative (p = 0.001). The Voice Handicap Index total score showed a statistically significant improvement from 71 points before surgery to 13 at 3 months after surgery (p = 0.008). CONCLUSIONS: Our study using intraoperative voice measurements indicate that the addition of arytenoid adduction to medialisation thyroplasty is a benefit in selected patients although more studies are needed due to the many limitations inherent to this field of investigation.

Implementation of a prototype dynamic laryngoplasty system in standing sedated horses provided arytenoid abduction control at seven days postoperatively.

OBJECTIVE: Evaluate a prototype dynamic laryngoplasty system (DLPS) in horses; a feasibility study. ANIMALS: 7 healthy Standardbred adult horses. METHODS: This was an in vivo experimental study. Horses had a standing surgical procedure to induce complete laryngeal hemiplegia, which was subsequently treated using the dynamic laryngoplasty system (DLPS). Activation of the DLPS was achieved using an injection port exiting through the skin (n = 2) or a subcutaneous injection port (n = 5). For each horse, endoscopic examinations of the upper respiratory tract were performed preoperatively, intraoperatively, and 7 days postoperatively. Left-to-right quotient ratios calculated during inactivated and activated states were obtained from still images of the rima glottidis acquired during day 7. In 3 horses, the device was intentionally overinflated to evaluate for device failure, and postmortem examinations were performed on day 7. For the remaining 4 horses, upper respiratory tract endoscopy was repeated at 1 month postoperatively, with no subsequent postmortem exam. RESULTS: No perioperative complications occurred, and the DLPS was effectively delivered in all horses under standing sedation. The left-to-right quotient ratio at day 7 postoperatively could be altered from a resting position of 0.76 (± 0.06) to a maximum of 0.97 (± 0.06; P < .05). The degree of arytenoid abduction could not be significantly altered after 1 month of device implantation, suspected to be due to peri-implant fibrosis. No coughing nor tracheal contamination was observed at all time points or during inflation. CLINICAL RELEVANCE: The ability to alter the degree of abduction at 7 days postoperatively with the DLPS may be beneficial in selective cases.

A Single Center Description of Adult and Pediatric Endoscopic Posterior Costal Cartilage Grafting.

OBJECTIVE: Posterior glottis impairment alters breathing, voicing, and swallowing. Bilateral vocal fold movement impairment (BVFMI) occurs when the vocal cords are fixed/remain midline. Studies inadequately assessed endoscopic posterior costal cartilage grafting (enPCCG) for BVFMI across broad ages. We aim to assess decannulation and prosthesis free airway in children and adults who have undergone enPCCG. STUDY DESIGN: Retrospective cohort. SETTING: Referral center. METHODS: This study included adults and children who received enPCCG for BVFMI (2010-2018) and were followed for 35 months on average. The main outcome was successful decannulation of patients, or airway improvement in those without tracheostomy. Data on comorbidities, surgical complications, and interventions following surgery were collected. RESULTS: Ten children and 11 adults underwent enPCCG for BVFMI. Eighty-one percent of patients had a tracheostomy at surgery; adults were more likely to have a tracheostomy at surgery (P = 0.035), and to undergo double-staged procedure (P = 0.035) and stent (P = 0.008). Average stent duration was 29.7 days. Overall decannulation rate was 76% (90% for children; 70% for adults). Children were more likely to receive postoperative intensive care unit care (P = 0.004). Adults had mean 4.4 post-enPCCG interventions per patient compared to children's mean 3.91 interventions. The most common interventions were steroid injection (17.6%) and balloon dilation (16%). Preliminary analysis suggests postoperative dysphonia was reported in 66.7% of patients; postoperative dysphagia was rare. CONCLUSION: EnPCCG was more successful at achieving decannulation in children. Adults required additional interventions. A double-staged operation with prolonged stenting is recommended for adult patients. A majority of patients were decannulated at last follow-up.

Management of Implant Extrusion following Thyroplasty for Vocal Fold Paralysis: A Case Report.

The most widely used laryngeal surgery technique for patients with vocal fold paralysis is medialization thyroplasty. Materials such as Gore-Tex, silastic, and hydroxyapatite are often used, and the most worrisome possible complication is extrusion of the implant. A 36-year-old female patient with a history of pediatric cardiac surgery was diagnosed with left vocal cord paralysis after an episode of upper respiratory infection with a working diagnosis of subclinical left vocal cord paralysis following cardiac surgery. She underwent medialization thyroplasty with a Gore-Tex implant under local anesthesia. On the 21st postoperative day, she presented with sudden-onset hoarseness and dysphagia due to Gore-Tex implant extrusion. The implant was removed and augmentation of the left vocal cord with adipose tissue was performed. Only 14 cases of Gore-Tex implant extrusion have been described in the literature so far. The aim of this case report was not only to show one possible complication when using a Gore-Tex implant but also to present fat augmentation as one of the solutions for revision medialization and salvage treatment, with sustained long-term results.

Endoscopic assisted microscopic posterior cordotomy for bilateral abductor vocal fold paralysis using radiofrequency versus coblation.

PURPOSE: To assess the outcomes of endoscopic assisted microscopic posterior cordotomy for bilateral abductor vocal fold paralysis (BAVFP) using radiofrequency versus coblation. METHODS: This was a randomized prospective cohort study that carried out on 40 patients with BAVFP who were subjected to endoscopic/assisted microscopic posterior cordotomy. The patients were randomly allocated into two groups: group (A) patients were operated with radiofrequency, and group (B) patients were operated with coblation. Glottic chink, grade of dyspnea, voice handicap index 10 (VHI10), and aspiration were evaluated pre-operatively and 2 weeks and 3 months post-operatively. RESULTS: There was a significant improvement in the glottic chink and VHI10 scores postoperatively with a non-significant difference between both groups regarding the degree of improvement. In addition, there was a significant improvement of the grade of dyspnea with a non-significant impact on the degree of aspiration in both groups post operatively. There was a lower incidence of oedema and granulation formation in the coblation group but without a statistical significance. CONCLUSION: Both techniques are effective alternatives for performing posterior transverse cordotomy in cases of BAVFP.

Changes in vocal fold gene expression and histology after injection augmentation in a recurrent laryngeal nerve injury model.

OBJECTIVE: To investigate changes in neuroregenerative pathways with vocal fold denervation in response to vocal fold augmentation. METHODS: Eighteen Yorkshire crossbreed swine underwent left recurrent laryngeal nerve transection, followed by observation or augmentation with carboxymethylcellulose or calcium hydroxyapatite at two weeks. Polymerase chain reaction expression of genes regulating muscle growth (MyoD1, MyoG and FoxO1) and atrophy (FBXO32) were analysed at 4 and 12 weeks post-injection. Thyroarytenoid neuromuscular junction density was quantified using immunohistochemistry. RESULTS: Denervated vocal folds demonstrated reduced expression of MyoD1, MyoG, FoxO1 and FBXO32, but overexpression after augmentation. Healthy vocal folds showed increased early and late MyoD1, MyoG, FoxO1 and FBXO32 expression in all animals. Neuromuscular junction density had a slower decline in augmented compared to untreated denervated vocal folds, and was significantly reduced in healthy vocal folds contralateral to augmentation. CONCLUSION: Injection augmentation may slow neuromuscular degeneration pathways in denervated vocal folds and reduce compensatory remodelling in contralateral healthy vocal folds.

Validation of the 10-Item Unilateral Vocal Fold Paralysis-Handicap Index quality of life questionnaire.

OBJECTIVES: To validate and test the reliability of the 10-Item Unilateral Vocal Fold Paralysis-Voice Handicap Index (UVFP-HI-10) quality of life (QoL) questionnaire for patients with UVFP. DESIGN: Prospective describe study based on perceptive surveys. PARTICIPANTS: We recruited 61 patients with UVFP and 53 healthy individuals comprised the control group. MAIN OUTCOME MEASURES: Both the patients and controls completed the UVFP-HI-10 questionnaire. A statistical analysis was performed to assess the internal consistency and validity of the survey. In addition, maximum phonation time (MPT) was used to objectively measure patient QoL. RESULTS: Internal consistency was high (α = .914) and the correlation with MPT was significant (rs = -0.722). The estimated marginal mean in the discriminant validity study was around seven times higher in the UVFP group compared to the controls. The UVFP-HI-10 cut-off value was more than 0.9 and the sensitivity and specificity were more than 0.8. CONCLUSIONS: The UVFP-HI-10 is a self-administered patient-reported outcome questionnaire with a high reliability and excellent criterion-based validity. This questionnaire can be used to evaluate specific clinical complaints (e.g., vocalisation, swallowing, and breathing) in terms of their impact on QoL in patients with UVFP. Thus, its use is appropriate as a basic assessment tool as part of a specific UVFP treatment protocol.

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.

Development and Application of Automated Vocal Fold Tracking Software in a Rat Surgical Model.

OBJECTIVE: The rat is a widely used model for studying vocal fold (VF) function after recurrent laryngeal nerve injury, but common techniques for evaluating rat VF motion remain subjective and imprecise. To address this, we developed a software package, called RatVocalTracker1.0 (RVT1.0), to quantify VF motion and tested it on rats with iatrogenic unilateral vocal fold paralysis (VFP). METHODS: A deep neural network was trained to identify the positions of the VFs and arytenoid cartilages (ACs) in transoral laryngoscope videos of the rat glottis. Software was developed to estimate glottic midline, VF displacement, VF velocity, and AC angle. The software was applied to laryngoscope videos of adult rats before and after right recurrent and superior laryngeal nerve transection (N = 15; 6M, 9F). All software calculated metrics were compared before and after injury and validated against manually calculated metrics. RESULTS: RVT1.0 accurately tracked and quantified VF displacement, VF velocity, and AC angle. Significant differences were found before and after surgery for all RVT1.0 calculated metrics. There was strong agreement between programmatically and manually calculated measures. Automated analysis was also more efficient than nearly all manual methods. CONCLUSION: This approach provides fast, accurate assessment of VF motion in rats with minimal labor and allows for quantitative comparison of lateral differences in movement. Through this novel analysis method, we can differentiate healthy movement from unilateral VFP. RVT1.0 is open-source and will be a valuable tool for researchers using the rat model for laryngology research. LEVEL OF EVIDENCE: NA Laryngoscope, 134:340-346, 2024.

Subtotal Submucosal Arytenoidectomy with Lateralization Sutures (SMALS) Covered by a Mucosal Flap.

OBJECTIVE: Glottic airway stenosis (GAWS) may result from bilateral paralysis (BVFP) or posterior glottic stenosis (PGS). Since the glottis is the principal airway sphincter, surgeons shift on the balance between airway, aspirations, and voice. We aim to describe our surgical technique and outcome of the SMALS procedure for GAWS correction. METHODS: A retrospective cohort of patients who underwent SMALS for PGS between 2018 and 2021. SMALS involves: endoscopic submucosal subtotal arytenoidectmy (preserving medial mucosal flap) and lateralization sutures. The sutures lateralize the mucosal flap to cover the arytenoidectomy bed without lateralization of the membranous vocal fold; expanding the posterior glottis, while preserving a relatively good voice. Covering the arytenoidectomy bed enhances healing. Medical and surgical data, airway, voice, and swallowing symptoms were collected. Relative glottic opening area (RGOA) and relative glottic insufficiency area (RGIA) were calculated. RESULTS: Eleven PGS patients who underwent 15 SMALS were included (4 bilateral), all patients had post-intubation PGS, 1 patient also had prior radiation to the larynx. All patients were tracheostomy-dependent. There were no major complications. No granulation or retracting scar was observed at follow-up. None had a persistent voice or swallowing disability. Successful outcome (decannulation) was achieved in 8 (73%); RGOA increased in all (Δ = 0.37; p = 0.003), while RGIA remained relatively stable (Δ = 0.02; p = 0.055). CONCLUSIONS: SMALS is a safe and effective, novel modification of the classic arytenoidectomy, for GAWS correction that can be easily applied and may expand the airway without significant glottic insufficiency symptoms. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:353-360, 2024.

Deep learning in voice analysis for diagnosing vocal cord pathologies: a systematic review.

OBJECTIVES: With smartphones and wearable devices becoming ubiquitous, they offer an opportunity for large-scale voice sampling. This systematic review explores the application of deep learning models for the automated analysis of voice samples to detect vocal cord pathologies. METHODS: We conducted a systematic literature review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. We searched MEDLINE and Embase databases for original publications on deep learning applications for diagnosing vocal cord pathologies between 2002 and 2022. Risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). RESULTS: Out of the 14 studies that met the inclusion criteria, data from a total of 3037 patients were analyzed. All studies were retrospective. Deep learning applications targeted Reinke's edema, nodules, polyps, cysts, unilateral cord paralysis, and vocal fold cancer detection. Most pathologies had detection accuracy above 90%. Thirteen studies (93%) exhibited a high risk of bias and concerns about applicability. CONCLUSIONS: Technology holds promise for enhancing the screening and diagnosis of vocal cord pathologies. While current research is limited, the presented studies offer proof of concept for developing larger-scale solutions.

Standing left recurrent laryngeal neurectomy for prospective evaluation of laryngeal hemiplegia evaluated by a high-speed treadmill test.

OBJECTIVE: To describe left recurrent laryngeal neurectomy (LRLn) performed under standing sedation and evaluate the effect of LRLn on upper respiratory tract function using a high-speed treadmill test (HST). We hypothesized that (1) unilateral LRLn could be performed in standing horses, resulting in ipsilateral arytenoid cartilage collapse (ACC); and (2) HST after LRLn would be associated with alterations in upper respiratory function consistent with dynamic ACC. ANIMALS: 6 Thoroughbred horses. METHODS: The horses were trained and underwent a baseline HST up to 14 m/s at 5% incline until fatigue. Evaluation included; airflow, pharyngeal and tracheal pressures, and dynamic upper respiratory tract endoscopy. Trans-laryngeal impedance (TLI) and left-to-right quotient angle ratio (LRQ) were calculated after testing. The following day, standing LRLn was performed in the mid-cervical region. A HST was repeated within 4 days after surgery. RESULTS: Standing LRLn was performed without complication resulting in Havemayer grade 4 ACC at rest (complete paralysis) and Rakestraw grade C or D ACC (collapse up to or beyond rima glottis midline) during exercise. Increasing treadmill speed from 11 to 14 m/s increased TLI (P < .001) and reduced LRQ (P < .001). Neurectomy resulted in an increase in TLI (P = .021) and a reduction in LRQ (P < .001). CLINICAL RELEVANCE: Standing LRLn induces laryngeal hemiplegia that can be evaluated using a HST closely after neurectomy. Standing LRLn may be useful for future prospective evaluations of surgical interventions for laryngeal hemiplegia.

Long-term voice outcomes of medialization thyroplasty with adjustable implant for unilateral vocal fold paralysis.

OBJECTIVES: Medialization thyroplasty (MT) using various implants has been employed as a corrective procedure for unilateral vocal fold paralysis (UVFP). A newly developed APrevent® vocal implant system (VOIS) offers an innovative solution with a finely adjustable design. This study aimed to investigate the long-term functional voice outcomes and benefits of postoperative adjustments in patients receiving MT using the VOIS-implant. METHODS: This is a prospective case series study at single tertiary medical center. Fourteen adult patients diagnosed with UVFP received MT with the VOIS implant and were followed up for more than 1 year. Implant adjustment procedure by injecting 0.9% physiological saline solution was performed both during and after the surgery to optimize glottal closure and voice quality. Objective voice outcomes and acoustic parameters were assessed preoperatively and postoperatively at various timepoints. RESULTS: Thirteen patients (93%) received intraoperative balloon adjustment, ranging from 0.05to 0.12 ml. Four patients underwent adjustments postoperatively and exhibited a positive trend towards immediately improving acoustic voice quality. Our long-term results demonstrated a notable improvement after the surgery in voice quality, with significant decreases in VHI-30 and improvements in perceptual parameters of GRBAS scale, acoustic measures such as jitter and signal-to-noise ratio (p < 0.001) and cepstral peak prominence smoothed in sustained vowel and short sentences. The voice outcomes remained stable more than 1 year follow-up. CONCLUSIONS: Overall, MT with VOIS implantation provides a favorable long-term outcomes and stability in voice quality for patients with UVFP and also an effective tool for postoperative adjustment without major revision surgeries.

Management of Bilateral Vocal Fold Paralysis: A Systematic Review.

OBJECTIVE: To review the current literature about epidemiology, etiologies and surgical management of bilateral vocal fold paralysis (BVFP). DATA SOURCES: PubMED, Scopus, and Cochrane Library. REVIEW METHODS: A systematic review of the literature on epidemiology, etiologies, and management of adult patients with BVFP was conducted through preferred reporting items for systematic reviews and meta-analyses statements by 2 investigators. RESULTS: Of the 360 identified papers, 245 were screened, and of these 55 were considered for review. The majority (76.6%) of BVFP cases are iatrogenic. BVFP requires immediate tracheotomy in 36.2% of cases. Laterofixation of the vocal fold was described in 9 studies and is a cost-effective alternative procedure to tracheotomy while awaiting potential recovery. Unilateral and bilateral posterior transverse cordotomy outcomes were reported in 9 and 7 studies, respectively. Both approaches are associated with a 95.1% decannulation rate, adequate airway volume, but voice quality worsening. Unilateral/bilateral partial arytenoidectomy data were described in 4 studies, which reported lower decannulation rate (83%) and better voice quality outcome than cordotomy. Revision rates and complications vary across studies, with complications mainly involving edema, granuloma, fibrosis, and scarring. Selective posterior cricoarytenoid reinnervation is being performed by more surgeons and should be a promising addition to the BVFP surgical armamentarium. CONCLUSION: Depending on techniques, the management of BVFP may be associated with several degrees of airway improvements while worsened or unchanged voice quality. The heterogeneity between studies, the lack of large-cohort controlled randomized studies and the confusion with posterior glottic stenosis limit the draw of clear conclusion about the superiority of some techniques over others.