Cross-linked hyaluronan used as augmentation substance for treatment of glottal insufficiency: safety aspects and vocal fold function

Management of Severe Dysphonia and Dysphagia Following Lateral Skull Base Surgery

OBJECTIVES

Lateral skull base surgeries pose a risk of injuring the lower cranial nerves, leading to potential postoperative complications such as dysphonia and dysphagia. Conservative treatments have shown limited efficacy in addressing these resultant voice and swallowing dysfunctions, significantly impacting patient quality of life. This study aims to evaluate the safety and effectiveness of a combined surgical approach involving autologous fat injection laryngoplasty (AFIL) and transcervical cricopharyngeal myotomy (TCPM) in patients suffering from severe dysphonia and dysphagia following lateral skull base surgery.

METHODS

A retrospective analysis was conducted on 16 patients who underwent concurrent AFIL and TCPM to improve severe dysphonia and dysphagia following lateral skull base surgery. Preoperative and postoperative assessments of voice and swallowing functions were performed using the Voice Handicap Index-10 (VHI-10), GRBAS scale, maximum phonation time (MPT), the Chinese version of Swallow Quality-of-Life Questionnaire (CSWAL-QOL), and videofluoroscopic swallowing studies (VFSS).

RESULTS

The results demonstrated notable improvements in voice quality and swallowing function. The VHI-10 score improved significantly from a preoperative mean of 32.06 ± 4.92 to a postoperative 9.06 ± 5.24. The results of the perceptual parameters of the GRBAS scale also improved significantly. The MPT increased from a preoperative average of 3.91 ± 1.00 seconds to 9.14 ± 2.44 seconds postoperatively. The CSWAL-QOL scores significantly improved from a preoperative score of 92.44 ± 17.75 to 130.19 ± 26.07 postoperatively. The VFSS-SWAL scores decreased from 6.63 ± 1.36 before surgery to 3.56 ± 1.58 after surgery. Similarly, the Penetration Aspiration Scale (PAS) scores significantly dropped from 6.38 ± 1.05 preoperatively to 2.93 ± 1.48 postoperatively. Nine out of 11 patients were able to have their gastric tubes successfully removed after surgery. There were no significant postoperative complications.

CONCLUSION

Concurrent AFIL and TCPM present a promising reconstructive method for patients experiencing severe dysphonia and dysphagia following lateral skull base surgery, highlighting its value in the postoperative management of complex lower cranial nerve injuries.

Additional injection laryngoplasty as a salvage treatment for unilateral vocal fold paralysis

OBJECTIVES

Injection laryngoplasty (IL) has been widely used as an initial treatment option for unilateral vocal fold paralysis (UVFP). An additional (second) IL is considered a salvage treatment for unsatisfactory outcomes of initial IL resulting from inadequate injection or early resorption of the injection material. This study aims to evaluate the efficacy of additional IL, distinguishing between "salvage" (within 4 months) and "repeated" injections (beyond 4 months), and to analyze prognostic factors for successful outcomes.

METHODS

This retrospective study involved patients who received IL at Asan Medical Center from January 2014 to December 2020. Voice parameters were collected after each procedure, and those who conducted the statistical analysis were blinded to the study subjects. Among the 65 patients who underwent additional IL, 51 patients were enrolled in this study. Postinjection grade, roughness, breathiness, asthenia, strain (GRBAS) scales were used to determine satisfactory treatment outcomes. Success of the additional IL was defined as a postinjection grade of dysphonia score of 0 or 1, with a reduction in grade compared with the preinjection grade.

RESULTS

The mean age of the patients was 61.6 years. Out of a total of 51 patients, 37 were men participating in the study. The odds ratio represents the likelihood of success in the second IL. Improved voice outcome after the additional IL was maintained in 23 (45%) patients. Compared with the failure group, the success group had a longer injection time interval between the initial and additional injection (9.1 vs. 7.4 months, respectively, p = 0.010). The success group had a higher proportion of patients with injection intervals >6 months (73.9% vs. 42.9%, p = 0.026). Logistic regression analysis revealed an injection interval >6 months had an odds ratio of 0.265 (confidence interval: 0.080-0.874, p = 0.029).

CONCLUSIONS

Additional injections would benefit the patients whose voice outcomes are maintained for a longer period (>6 months) after the first injection.

Evaluation and Management of Inflammatory Reactions to Vocal Fold Injection Laryngoplasty with Hyaluronic Acid

OBJECTIVES

Inflammatory reaction to vocal fold injection laryngoplasty with hyaluronic acid (HA) is a rare condition whose optimal management is not established. In this study, we aim to review the presentation of these reactions and outline an approach for evaluation and management.

METHODS

We performed a retrospective review of all patients at our institution who underwent vocal fold injection augmentation with HA during the period extending from August 2018 until October 2022. We then identified patients with postinjection inflammatory reaction and reviewed demographic data, indication for injection, amount of HA injected, setting of procedure, and symptoms. The types of complication, management plan, onset, and time to complete resolution were also recorded. A comprehensive literature search for similar complications was conducted for comparative analysis. Once the available data were aggregated with our institutional experience, we developed an algorithmic approach to manage this condition.

RESULTS

We identified 83 patients (124 vocal folds) who underwent vocal fold injection laryngoplasty with HA over a 4-year period. Four patients (4.8%) had a postprocedure inflammatory reaction (5.6% of all vocal folds). Of the four patients, three presented with dyspnea and stridor, while one presented with dysphonia, with onset of symptoms ranging from 24 to 48 hour postinjection. All patients were treated with corticosteroids. For comparative analysis, we identified 24 patients from the literature with reported inflammatory reactions to HA.

CONCLUSION

We suggest an algorithmic approach to managing laryngeal inflammation following HA injection. Familiarity with treatment for this rare complication is essential to avoid significant morbidity and achieve optimal outcomes.

LEVEL OF EVIDENCE: 4

Local Reaction Causing Airway Compromise Following Vocal Fold Injection Augmentation with Carboxymethylcellulose

OBJECTIVES

This case report aims to identify local allergic reaction as a rare complication of vocal fold injection augmentation with carboxymethylcellulose and discuss the management of airway swelling following this reaction.

INTRODUCTION

Glottis insufficiency due to true vocal fold immobility is important to manage to reduce risk of aspiration and improve voice function. Vocal fold injection augmentation with carboxymethylcellulose is considered a safe and effective treatment for glottis insufficiency, commonly due to vocal fold immobility.

METHODS

Retrospective medical records review and case report.

RESULTS

We report a unique case of an adult female with vocal fold immobility that was treated with injection laryngoplasty using carboxymethylcellulose and subsequently developed a local reaction requiring intubation and tracheostomy placement.

CONCLUSION

Otolaryngologists should be aware of this rare, but life-threatening complication and counsel patients accordingly when obtaining consent. If there are signs and symptoms of airway edema, the patient should be transferred to the ICU for airway watch, intravenous steroids, and possible intubation.

Hyaluronic Acid: A Valid Therapeutic Option for Early Management of Genitourinary Syndrome of Menopause in Cancer Survivors?

Genitourinary syndrome of menopause (GSM) is a chronic condition affecting a large number of women, with a major impact on their urogenital health and sexual function. It occurs at midlife because estrogen levels decline with menopause enhancing aging-related changes of the functional anatomy of the urogenital system. Unfortunately, GSM may occur early in the lifespan of women or be exacerbated following anticancer treatments, such as chemotherapy, ionizing radiation, or surgical removal of reproductive organs. Symptoms of GSM are often under-reported by women, under-estimated and under-diagnosed by health care providers (HCPs), and subsequently under-treated, despite their profound negative impact on the quality of life. The mainstay of vaginal treatments is local estrogen therapy (LET) ensuring an effective management of moderate to severe symptomatic GSM. However, LET is generally contraindicated in women with a history of hormone receptor positive cancer, due to the fear of increased recurrence or possible interference with endocrine adjuvant therapies. Among non-hormonal treatments, hyaluronic acid-based moisturizers have shown promising clinical results both in healthy women and in cancer patients or survivors. Its strong water-binding properties provide lubricating and moisturizing effects, which contribute to maintaining a proper level of hydration and viscoelasticity in several body parts, including the urinary tract and genital tissues. Hyaluronic acid-based moisturizers are effective, safe, and well tolerated; therefore, they may represent a valid option for the early management of GSM-associated symptoms in every woman with a history of cancer who is unable or unwilling to undergo hormone-based therapies. Hence, the aim of this review was to provide an overview of GSM etiology and treatment in women with natural or iatrogenic menopause, with a focus on the use of hyaluronic acid as a prophylactic treatment in the context of an integrated management protocol for cancer patients.

Inflammatory Reactions to Laryngeal Injection of Hyaluronic Acid Derivatives

OBJECTIVES/HYPOTHESIS

To report the rate and describe the characteristics and management of inflammatory reactions following injection laryngoplasty with hyaluronic acid derivatives.

STUDY DESIGN

Single institution, retrospective review.

METHODS

Adult and pediatric patients who underwent injection laryngoplasty with hyaluronic acid derivatives from 2013 to 2020 were identified. Demographics, indication for injection, type and volume of injected material, and use of general anesthesia were obtained. When a postoperative inflammatory response occurred, information regarding clinical presentation, timing, and subsequent management was collected.

RESULTS

A total of 464 patients who underwent 536 laryngeal injections with hyaluronic acid derivatives were included. There were 365 adult patients (median age 62 years) who underwent 431 injections and 99 pediatric patients (median age 2 years) who underwent 105 injections. The most common indications for injection were abnormal vocal fold mobility (70.3%) and aspiration (83.8%) for adult and pediatric patients, respectively. Juvéderm® was used in 449 cases (79.8% adult, 100% pediatric), and Restylane® was used in the remaining adult cases (20.2%). Procedures were mostly performed under general anesthesia (67.7% adult, 100% pediatric) with median injection volumes of 0.6 mL for adult and 0.3 mL for pediatric patients. An inflammatory reaction occurred following 3 of 536 injections (0.6%), all utilizing Juvéderm®. All three patients presented with stridor, dyspnea, and laryngeal edema within two days of injection. Each patient was admitted for observation and successfully treated with intravenous steroids and inhaled racemic epinephrine. One patient with comorbid pneumonia was intubated and required concomitant treatment with broad-spectrum antibiotics.

CONCLUSIONS

Inflammatory reactions to hyaluronic acid derivatives used in injection laryngoplasty are rare but represent significant patient morbidity and can be managed with anti-inflammatory and airway stabilizing measures. Patients should be counseled appropriately regarding the risks of injection laryngoplasty with hyaluronic acid derivatives.

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.

Adverse events following injection laryngoplasty: An analysis of the MAUDE database

OBJECTIVE

Injection laryngoplasty (IL) is considered safe in both the operating room and clinical setting. However, safety data is limited to single-institution studies with reduced sample sizes. The objective of this study is to examine a national database for adverse events related to IL in an effort to further confirm the safety of this procedure and better characterize potential complications.

MATERIALS AND METHODS

Retrospective analysis of the Manufacturer and User Facility Device Experience (MAUDE) database for reported adverse events of IL procedures utilizing calcium hydroxyapatite (CAHA), hyaluronic acid (HA) and carboxymethylcellulose (CMC) implants from 2009 to 2020.

RESULTS AND ANALYSIS

We identified 47 reported adverse events. The average patient age was 54 years old. 59.3% of patients were female. Adverse events more frequently involved the use of CAHA compared to HA or CMC (n = 27, 57.4%, n = 13, 27.7% and n = 7, 14.9%, respectively). The most common adverse events were laryngeal edema (n = 18, 39.1%), improper placement of injected material (n = 12, 26.1%), persistent dysphonia (n = 13, 28.3%), and post-injection dysphagia or odynophagia (n = 11, 23.9%). Major events, defined as requiring emergency room treatment, hospitalization, or surgical intervention accounted for 29 (60.4%) of cases. Four cases of edema required intubation, and one patient necessitated a surgical airway.

CONCLUSION

Complications arising from IL range from minor events to airway obstruction and may happen with a variety of injectable materials including CAHA, HA and CMC. Few cases of airway obstruction requiring immediate intervention were identified, confirming the safety of IL in both the operative and office setting.

Effect of a Single Injection of Basic Fibroblast Growth Factor into the Vocal Folds: A 36-Month Clinical Study

OBJECTIVE

A single injection of basic fibroblast growth factor (bFGF) into the vocal folds of patients with glottal insufficiency has been shown to be effective for a few years. However, the long-term therapeutic effect of a single injection of bFGF into the vocal folds has yet to be demonstrated. In this study, the therapeutic effect of a single injection of bFGF into the vocal folds was investigated over several years by monitoring patients for 36 months following this treatment.

METHODS

Nineteen patients with glottal insufficiency received injections of bFGF diluted to 20 μg/mL in the superficial layer of the lamina propria of the bilateral vocal folds. The following parameters were evaluated at preinjection baseline and 6, 12, 18, 24, and 36 months later, and statistical comparisons were performed. The parameters evaluated were: the Grade, Rough, Breathy, Asthenic, and Strained (GRBAS) scale score; maximum phonation time; acoustic analysis; and glottal wave analysis (GWA) and kymograph edge analysis (KEA) using high-speed digital imaging (HSDI). The amplitude perturbation quotient (APQ) and period perturbation quotient (PPQ) were measured by acoustic analysis. The mean minimum glottal area during vocalization and mean minimum distance between the vocal folds were measured by GWA. The amplitudes of the bilateral vocal folds were measured by KEA.

RESULTS

Postinjection, the GRBAS scale score decreased from 6 months after injection, and maximum phonation time was prolonged. The mean minimum glottal area during vocalization and the mean minimum distance between the vocal folds calculated by GWA of HSDI decreased significantly after 6 months. These effects persisted until 36 months postinjection. APQ and PPQ derived from acoustic analysis tended to decrease, but not significantly. There was no clear change in the amplitudes of the bilateral vocal folds calculated by KEA of HSDI before and after injection.

CONCLUSIONS

These results suggest that the effects of a single injection of bFGF into the vocal folds persist for 36 months.

Fibrin Gel Suspended Autologous Chondrocytes as Cell-based Material for long-term Injection Laryngoplasty

OBJECTIVES/HYPOTHESIS

Injection laryngoplasty of materials for unilateral vocal-fold paralysis has shown various results regarding the long-term stability of the injected material. We evaluated a fibrin-gel based cell suspension with autologous chondrocytes in-vitro and in-vivo as long-term-stable vocal-fold augmentation material in an animal model.

STUDY DESIGN

This study compises an in vitro cell-culture part as well as an in vivo animal study with New Zealand White Rabbits.

METHODS

In in-vitro experiments, auricular chondrocytes harvested from 24 New Zealand White Rabbits cadavers were cultivated in pellet cultures to evaluate cartilage formation for 4 weeks using long-term-stable fibrin gel as carrier. Injectability and injection volume for the laryngoplasty was determined in-vitro using harvested cadaveric larynxes. In-vivo 24 Rabbits were biopsied for elastic cartilage of the ear and autologous P1 cells were injected lateral of one vocal cord into the paraglottic space suspended in a long-term-stable fibrin gel. Histologic evaluation was performed after 2, 4, 12, and 24 weeks.

RESULTS

During 12-week pellet culture, we found extracellular matrix formation and weight-stable cartilage of mature appearance. In-vivo, mature cartilage was found in two larynxes (n = 6) at 4 weeks, in four (n = 6) at 12 weeks, and in five (n = 6) at 24 weeks mostly located in the paraglottic space and sometimes with spurs into the vocalis muscle. Surrounding tissue was often infiltrated with inflammatory cells. Material tended to dislocate through the cricothyroid space into the extraglottic surrounding tissue.

CONCLUSIONS

A cell-based approach with chondrocytes for permanent vocal-fold augmentation has not previously been reported. We have achieved the formation of structurally mature cartilage in the paraglottic space, but this is accompanied by difficulties with dislocated material, deformation of the augmentation, and inflammation.

LEVEL OF EVIDENCE

N/A Laryngoscope, 131:E1624-E1632, 2021.

Hyaluronic Acid Injection Laryngoplasty for Unilateral Vocal Fold Paralysis-A Systematic Review and Meta-Analysis

Unilateral vocal fold paralysis (UVFP) is a common disorder that may cause glottal closure insufficiency and then hoarseness of voice and aspiration during swallowing. We conducted a systematic review and meta-analysis to evaluate whether hyaluronic acid (HA) injection laryngoplasty (IL) is an effective treatment for patients with UVFP. Comprehensive systematic searches were undertaken using PubMed, EBSCO Medline, and Cochrane Library databases. We appraised the quality of studies according to preset inclusion and exclusion criteria. The lengths of follow-up were divided into “short-term” (3 months or shorter), “medium-term” (6 months), and “long-term” (12 months or longer). We performed random-effect meta-analysis to estimate the changes in voice-related quality of life, perceptual evaluation by grading systems, voice lab analysis of maximal phonation time, and normalized glottal gap area, before and after HA IL. Fourteen studies were eligible for the final analysis. The results showed that patients’ glottal closure insufficiency could be improved; maximal phonation time could be prolonged; perceptual evaluations of the voice and quality of life were better after HA IL, but the duration of treatment effect varied among different studies. In conclusion, HA IL is an effective treatment for UVFP, which may achieve a long-term effect and therefore reduce the likelihood of requiring permanent medialization thyroplasty.

Treatment Efficacy of Voice Therapy Following Injection Laryngoplasty for Unilateral Vocal Fold Paralysis

OBJECTIVES

Injection laryngoplasty (IL) is performed to reduce the gap between vocal folds induced by unilateral vocal fold paralysis (UVFP). Voice quality after IL may be different due to other factors that influence voice quality. Voice therapy has been reported to improve voice quality after IL in patients with UVFP. This study evaluated the efficacy of voice therapy combined with IL.

METHODS

Patients with UVFP who underwent IL as primary therapy from March 2017 to June 2019 were evaluated. The enrolled patients were divided into two groups, those who did and did not receive voice therapy after IL. Voice quality was evaluated using perceptual, acoustic, and aerodynamic parameters, and voice handicap index-30 scores one month after IL and after completing each treatment.

RESULTS

Of 261 patients who underwent IL during the study period, 40 were enrolled, including 21 who did and 19 who did not receive voice therapy. Voice parameters one month after IL did not differ between these two groups. Jitter, shimmer, noise-to-harmonic ratio, and mean flow rate decreased, while maximum phonation time increased after voice therapy (both P < 0.05). In the absence of voice therapy, improved voice parameters were maintained for six months after IL. Total voice handicap index-30 scores decreased, from 35.6 to 19.1 (P < 0.05), in patients who received voice therapy.

CONCLUSION

Voice therapy following IL is beneficial to patients with UVFP. Combined treatment can help to maintain improved voice quality more than six months after IL.

Laryngeal Electromyography-Guided Hyaluronic Acid Vocal Fold Injections for Glottic Insufficiency

OBJECTIVES

To assess voice outcomes using the novel technique of in-office laryngeal electromyography-guided vocal fold injections (LEVFI) with hyaluronic acid to treat glottal insufficiency. Secondary objectives included determining the complication/completion rates and if any factors were associated with improved voice outcomes.

METHODS

Retrospective review of patients who received their first LEVFI from August 2017 to December 2018. Three- and six-month voice outcomes were assessed. Outcomes included voice handicap index-10 (VHI-10), maximum phonation time (MPT), perceptual analysis of voice (GRBAS), fundamental frequency, and stroboscopy.

RESULTS

Of the 121 eligible patients (55.4% male, age 63.7 years), 94 (77.7%) had complete 3-month data and 59 (48.8%) had complete 6-month data. VHI-10 was significantly improved from 25.7 ± 7.5 to 20.9 ± 10.9 at 3 months (P < .001) and to 19.1 ± 11.5 at 6 months (P < .001). MPT improved from 6.2 ± 5.4 seconds to 9.4 ± 7.1 seconds at 3 months (P < .001) and to 11.3 ± 8.2 seconds at 6 months (P < .001). GRBAS was improved in 74.8% of patients ([65.2, 82.8] 95% CI) at 3 months and 80.8% ([69.9, 89.1]) 95% CI) at 6 months. Stroboscopy showed a glottic gap improvement in 74.8% of patients ([65.8, 82.4] 95% CI) at 3 months and in 80.3% ([65.9, 88.5] 95% CI) at 6 months. Fundamental frequency was unchanged, as expected. Multivariate analysis reported that no factors were associated with better voice outcomes. Overall, 177/181 (97.8%) injections were completed. There were no complications.

CONCLUSION

In-office LEVFI is an effective, novel technique to treat glottic insufficiency with improved voice outcomes, high completion rate, and no significant complications.

Hyaluronan Hydrogels for the Local Delivery of Mesenchymal Stromal Cells to the Injured Vocal Fold

Mesenchymal stromal cells (MSCs) promote wound healing by expediting the inflammatory phase. Local injection of MSCs into injured vocal folds (VFs) is effective in animal models, suggesting suitability for clinical translation. Despite their therapeutic potential, MSCs do not persist within the VF. This study evaluates whether hyaluronan (HA) hydrogels offer a safe delivery vehicle for local injection of MSCs into VFs, and increase longevity of the cells within the injured tissue. MSCs ± HA hydrogel were exposed to interleukin (IL)1β, IL8, and chemokine (C-C motif) ligand 4, and evaluated for mRNA expression of matrix remodeling genes and secretion of immunomodulatory/prohealing factors. Chemotaxis/invasion in response to inflammation was evaluated. A lapin model of VF injury evaluated in vivo effects of MSCs ± HA hydrogel on enhancing VF healing. Histological evaluation of inflammation, type I collagen expression, HA hydrogel resorption, and MSC persistence was evaluated at 3 and 25 days after injury. MSCs within HA hydrogel were responsive to their extracellular environment, upregulating immunomodulatory factors when exposed to inflammation. Despite delayed migration out of the gel in vitro, the MSCs did not persist longer within the injured tissue in vivo. MSCs ± HA hydrogel exerted equivalent dampening of inflammation in vivo. The gel was resorbed within 25 days and no edema was evident. HA hydrogels can be safely used in the delivery of MSCs to injured VFs, minimizing leakage of administered cells. MSCs within the HA hydrogel did not persist longer than those in suspension, but did exert comparable therapeutic effects.

Speech and language therapy for management of chronic cough

BACKGROUND

Cough both protects and clears the airway. Cough has three phases: breathing in (inspiration), closure of the glottis, and a forced expiratory effort. Chronic cough has a negative, far-reaching impact on quality of life. Few effective medical treatments for individuals with unexplained (idiopathic/refractory) chronic cough (UCC) are known. For this group, current guidelines advocate the use of gabapentin. Speech and language therapy (SLT) has been considered as a non-pharmacological option for managing UCC without the risks and side effects associated with pharmacological agents, and this review considers the evidence from randomised controlled trials (RCTs) evaluating the effectiveness of SLT in this context.

OBJECTIVES

To evaluate the effectiveness of speech and language therapy for treatment of people with unexplained (idiopathic/refractory) chronic cough.

SEARCH METHODS

We searched the Cochrane Airways Trials Register, CENTRAL, MEDLINE, Embase, CINAHL, trials registries, and reference lists of included studies. Our most recent search was 8 February 2019.

SELECTION CRITERIA

We included RCTs in which participants had a diagnosis of UCC having undergone a full diagnostic workup to exclude an underlying cause, as per published guidelines or local protocols, and where the intervention included speech and language therapy techniques for UCC.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of 94 records. Two clinical trials, represented in 10 study reports, met our predefined inclusion criteria. Two review authors independently assessed risk of bias for each study and extracted outcome data. We analysed dichotomous data as odds ratios (ORs), and continuous data as mean differences (MDs) or geometric mean differences. We used standard methods recommended by Cochrane. Our primary outcomes were health-related quality of life (HRQoL) and serious adverse events (SAEs).

MAIN RESULTS

We found two studies involving 162 adults that met our inclusion criteria. Neither of the two studies included children. The duration of treatment and length of sessions varied between studies from four sessions delivered weekly, to four sessions over two months. Similarly, length of sessions varied slightly from one 60-minute session and three 45-minute sessions to four 30-minute sessions. The control interventions were healthy lifestyle advice in both studies.One study contributed HRQoL data, using the Leicester Cough Questionnaire (LCQ), and we judged the quality of the evidence to be low using the GRADE approach. Data were reported as between-group difference from baseline to four weeks (MD 1.53, 95% confidence interval (CI) 0.21 to 2.85; participants = 71), revealing a statistically significant benefit for people receiving a physiotherapy and speech and language therapy intervention (PSALTI) versus control. However, the difference between PSALTI and control was not observed between week four and three months. The same study provided information on SAEs, and there were no SAEs in either the PSALTI or control arms. Using the GRADE approach we judged the quality of evidence for this outcome to be low.Data were also available for our prespecified secondary outcomes. In each case data were provided by only one study, therefore there were no opportunities for aggregation; we judged the quality of this evidence to be low for each outcome. A significant difference favouring therapy was demonstrated for: objective cough counts (ratio for mean coughs per hour on treatment was 59% (95% CI 37% to 95%) relative to control; participants = 71); symptom score (MD 9.80, 95% CI 4.50 to 15.10; participants = 87); and clinical improvement as defined by trialists (OR 48.13, 95% CI 13.53 to 171.25; participants = 87). There was no significant difference between therapy and control regarding subjective measures of cough (MD on visual analogue scale of cough severity: -9.72, 95% CI -20.80 to 1.36; participants = 71) and cough reflex sensitivity (capsaicin concentration to induce five coughs: 1.11 (95% CI 0.80 to 1.54; participants = 49) times higher on treatment than on control). One study reported data on adverse events, and there were no adverse events reported in either the therapy or control arms of the study.

AUTHORS' CONCLUSIONS

The paucity of data in this review highlights the need for more controlled trial data examining the efficacy of SLT interventions in the management of UCC. Although a large number of studies were found in the initial search as per protocol, we could include only two studies in the review. In addition, this review highlights that endpoints vary between published studies.The improvements in HRQoL (LCQ) and reduction in 24-hour cough frequency seen with the PSALTI intervention were statistically significant but short-lived, with the between-group difference lasting up to four weeks only. Further studies are required to replicate these findings and to investigate the effects of SLT interventions over time. It is clear that SLT interventions vary between studies. Further research is needed to understand which aspects of SLT interventions are most effective in reducing cough (both objective cough frequency and subjective measures of cough) and improving HRQoL. We consider these endpoints to be clinically important. It is also important for future studies to report information on adverse events.Because of the paucity of data, we can draw no robust conclusions regarding the efficacy of SLT interventions for improving outcomes in unexplained chronic cough. Our review identifies the need for further high-quality research, with comparable endpoints to inform robust conclusions.

Adverse Reaction to Restylane: A Review of 63 Cases of Injection Laryngoplasty

The aim of this study is to review the prevalence of adverse reactions to cross-linked hyaluronic acid (HA) following injection laryngoplasty and discuss possible mechanisms. A retrospective chart review of patients who underwent injection laryngoplasty using HA was conducted. Demographic data included age, gender, etiology, site of injection, and amount injected. Adverse reaction was diagnosed by the presence of inflammatory reaction at the injection site. A total of 63 patients were included, divided into 41 males and 22 females with a mean age of 51.76 years. The most common etiology was vocal cord paralysis (n = 53), followed by postcordectomy, puberphonia, and vocal fold atrophy and bowing. The average amount injected was 0.56 (0.22) mL. Three cases out of 63 patients developed an adverse reaction and presented with airway symptoms, namely, progressive shortness of breath and globus 2 to 3 days postinjection. Adverse reactions following HA injection laryngoplasty may occur with life-threatening symptoms.

Vocal Fold Injection of Absorbable Materials: A Histologic Analysis With Clinical Ramifications

Objectives:

Gels composed of carboxymethylcellulose (CMC) and cross-linked hyaluronic acid are commonly used as temporary or resorbable injectable materials for vocal fold medialization. However, there is limited information about tissue injection patterns, soft tissue reaction, degradation, and residence time, particularly for the newer CMC gels.

Study Design:

Prospective, laboratory.

Methods:

Ten canines underwent paraglottic (deep to the vocal ligament) microlaryngoscopic injection with about 100 µL (0.1 mL) of cross-linked hyaluronic acid (Restylane) in the right vocal fold and about 100 µl (0.1 mL) of CMC gel in the left vocal fold. Two commercial CMC gels of similar formulation (Prolaryn Gel and Renú Gel) were used in 5 animals each. Two subjects were sacrificed for histologic analysis at 3, 13, 29, 42, and 55 days.

Results:

Histology showed that injected Restylane formed cohesive ovoid-shaped aggregated implants with minimal dispersion, inflammation, or cellular invasion in all subjects. Approximately 86% of Restylane injected remained at 8 weeks, as estimated from postmortem, high-resolution magnetic resonance imaging scans. In contrast, histology showed that both CMC gels dispersed widely through fascial planes during and after injection within and outside the thyroarytenoid muscle fascicles. There was a robust macrophage and histiocyte phagocytic response, with moderate to severe inflammation noted around residual CMC gel at early time points, and at 6 to 8 weeks, very little free gel was observed.

Conclusions:

None of the studied materials induced a clinical inflammatory reaction on laryngoscopy such that they would be considered problematic or dangerous. Restylane demonstrated superior injection localization, tissue compatibility, and residence time. Both CMC gels did not localize well in the paraglottic region, and there was a robust inflammatory response, with clearance by macrophages and short residence time. These results suggest that CMC gels may have a more limited application than previously thought for vocal fold medialization in patients in whom the injection is being used to achieve voice enhancement while awaiting reinnervation. Level of Evidence: NA

Speech disorders in Parkinson's disease: pathophysiology, medical management and surgical approaches

The prevalence of speech disorders among individuals with Parkinson's disease (PD) has been reported to be as high as 89%. Speech impairment in PD results from a combination of motor and nonmotor deficits. The production of speech depends upon the coordination of various motor activities: respiration, phonation, articulation, resonance and prosody. A speech disorder is defined as impairment in any of its inter-related components. Despite the high prevalence of speech disorders in PD, only 3–4% receive speech treatment. Treatment modalities include pharmacological intervention, speech therapy, surgery, deep brain stimulation and vocal fold augmentation. Although management of Parkinsonian dysarthria is clinically challenging, speech treatment in PD should be part of a multidisciplinary approach to patient care in this disease.

Histopathologic Evaluation of Hyaluronic Acid and Plasma-Rich Platelet Injection into Rabbit Vocal Cords: An Experimental Study

Objective

Various materials are used by otolaryngologists for vocal cord injections in the management of vocal cord paralysis. An ideal injection material should be long-term effective, readily available, cheap, easy to prepare, have no donor morbidity, easy to use, biocompatible, resistant to resorption or migration, and easy to extract during revision. In this study, we aimed to see the histopathological effects of hyaluronic acid (HYA) and platelet-rich plasma (PRP) injections into the vocal cords of New Zealand rabbits.

Methods

PRP was injected into the right vocal cords of twelve rabbits, which was prepared from their serum (PRP group). HYA was injected into the left vocal cords of first six rabbits (numbered 1-6) (HYA group), and the left vocal cords of the other six rabbits (numbered 7-12) were followed with no intervention (control group). Two months later, histomorphological findings in the vocal cords were assessed by two experienced pathologists in seven parameters: chronic inflammation, mucosal atrophy, necrosis, neovascularization, fibrosis, foreign body reaction, and muscular atrophy. They were scored double-blinded as negative (0), mild (+1), moderate (+2), and severe (+3). Fisher's chi-square test was used to evaluate any statistical significance among the three groups.

Results

Chronic inflammation, mucosal atrophy, necrosis, foreign body reaction, and muscular atrophy parameters were scored as "0" for each preparate by both pathologists. For neovascularization and fibrosis, a stasistically significant difference was seen among the three groups (p<0.05). Neovascularization was increased in the PRP and HYA groups compared with the control group. No significant difference was observed in fibrosis when the groups were compared separately. After two months, two of the six vocal cords injected with HYA revealed HYA; however, none of the PRP-injected vocal cords showed PRP.

Conclusion

HYA and PRP can be safely injected into vocal cords. Our findings show that HYA is a biocompatible and safe injection material for clinical use. Only two of the six vocal cords showed HYA at the end of two months, suggesting that HYA is a short-term effective material. Similarly, PRP was also shown to be a short-term effective material and can be used in patients for testing purpose before using a long-term effective material. The advantages of PRP are that it is inexpensive, readily available, and completely inert as it is prepared from the subject itself.

Subcutaneous Neurotrophin 4 Infusion Using Osmotic Pumps or Direct Muscular Injection Enhances Aging Rat Laryngeal Muscles

Laryngeal dysfunction in the elderly is a major cause of disability, from voice disorders to dysphagia and loss of airway protective reflexes. Few, if any, therapies exist that target age-related laryngeal muscle dysfunction. Neurotrophins are involved in muscle innervation and differentiation of neuromuscular junctions (NMJs). It is thought that neurotrophins enhance neuromuscular transmission by increasing neurotransmitter release. The neuromuscular junctions (NMJs) become smaller and less abundant in aging rat laryngeal muscles, with evidence of functional denervation. We explored the effects of NTF4 for future clinical use as a therapeutic to improve function in aging human laryngeal muscles. Here, we provide the detailed protocol for systemic application and direct injection of NTF4 to investigate the ability of aging rat laryngeal muscle to remodel in response to NTF4 application. In this method, rats either received NTF4 either systemically via osmotic pump or by direct injection through the vocal folds. Laryngeal muscles were then dissected and used for histological examination of morphology and age-related denervation.

A Review of Hyaluronic Acid and Hyaluronic Acid-based Hydrogels for Vocal Fold Tissue Engineering

Vocal fold scarring is a common cause of dysphonia. Current treatments involving vocal fold augmentation do not yield satisfactory outcomes in the long term. Tissue engineering and regenerative medicine offer an attractive treatment option for vocal fold scarring, with the aim to restore the native extracellular matrix microenvironment and biomechanical properties of the vocal folds by inhibiting progression of scarring and thus leading to restoration of normal vocal function. Hyaluronic acid is a bioactive glycosaminoglycan responsible for maintaining optimum viscoelastic properties of the vocal folds and hence is widely targeted in tissue engineering applications. This review covers advances in hyaluronic acid-based vocal fold tissue engineering and regeneration strategies.

Electromyography-guided hyaluronic acid injection laryngoplasty in early stage of unilateral vocal fold paralysis

INTRODUCTION AND OBJECTIVE

To assess the effectiveness of electromyography-guided hyaluronic acid injection laryngoplasty in the early stage of unilateral vocal fold paralysis in terms of patient recovery from dysphonia and quality of life.

METHODS

Between January and December 2014, 28 patients with unilateral vocal fold paralysis underwent electromyography and injection of hyaluronic acid in the thyroarytenoid muscle. We compared the voice handicap index, grade, roughness, breathiness, asthenia, strain scale (GRBAS), videostroboscopic parameters and maximum phonation time assessed before, 15 days and 6 months after the intervention, using the non-parametric Wilcoxon rank test.

RESULTS

Out of the 28 patients, 1 had a haematoma in the injected vocal fold (3.57%) and 6 required second injections. The maximum phonation time of the vowel /e/ increased from 6.07 to 12.14 sec. (15 days post-intervention) and subsequently 12.75 (6 months post-intervention). There was also a significant improvement in the grade, roughness, breathiness, asthenia, strain scale in parameters G, B and A both 15 days and 6 months after the intervention. The voice handicap index score decreased from 58.29 to 37.63 (15 days post-intervention) and 29.64 (6 months post-intervention).

CONCLUSIONS

Electromyography-guided hyaluronic injection laryngoplasty in unilateral vocal fold paralysis enables, in the same intervention, neuromuscular assessment and temporary treatment of glottic insufficiency with a low risk of complications and improvement in patient's quality of life. This may reduce the need for subsequent treatments, but further research is required to confirm these findings.

A comparative study of voice outcomes and complication rates in patients undergoing injection laryngoplasty performed under local versus general anaesthesia: an Adelaide voice specialist's experience

Objective:

To compare clinical outcomes and complication rates in patients undergoing injection laryngoplasty performed under local versus general anaesthesia.

Methods:

A retrospective review was conducted of patients who underwent injection laryngoplasty performed by a single laryngologist in a tertiary Australian laryngology centre, between February 2013 and December 2014. Patient demographics, anaesthetic modality and complications were recorded. Voice Handicap Index 10 and the Grade, Breathiness, Roughness, Asthenia, Strain scale were evaluated.

Results:

Thirty-four laryngoplasties were performed under general anaesthesia and 41 under local anaesthesia, with mean patient ages of 59.5 and 68.8 years, respectively. Voice Handicap Index 10 scores were significantly improved post-injection (p< 0.001), with no significant difference between general anaesthesia and local anaesthesia (p> 0.05). All aspects of the Grade, Breathiness, Roughness, Asthenia, Strain scale showed significant improvement post-injection, except asthenia. There were seven (9.3 per cent) minor complications (five in the general anaesthesia group, two in the local anaesthesia group), all managed conservatively.

Conclusion:

Injection laryngoplasties performed under general anaesthesia and local anaesthesia offer similar voice outcomes, with comparable complication rates. Hence, development of a management algorithm for injection laryngoplasties performed under local anaesthesia is recommended.

Investigation of a Novel Cross-Linked Hyaluronan Hydrogel for Use as a Soft-Tissue Filler

Objective:

To investigate an innovative tyramine-based hyaluronan (TB-HA) biomaterial for soft-tissue augmentation. Specifically, to test: (1) the ability of the TB-HA biomaterial to be injected subcutaneously; and (2) to test the in vivo response of the TB-HA biomaterial in an immunocompetent animal model.

Introduction:

Hyaluronan (HA) is a normal component of most tissues and, as such, is nonimmunogenic, nontoxic, and noninflammatory. Cross-linked hydrogels are formed from HA by substitution (approximately 5%) with tyramine followed by enzymatic cross-linking with peroxidase in the presence of very dilute hydrogen peroxide. From a single formulation of tyramine-substituted HA (TS-HA), a full spectrum of biomaterial properties can be produced by varying the HA concentration before cross-linking. The properties of these biomaterials ranged from a soft, optically clear hydrogel (6.25 mg/mL), suitable for soft-tissue augmentation as an injectable material, to a paste-like material (12.5–25.0 mg/mL).

Materials and Methods:

The hydrogel was evaluated in vivo as an injectable material (6.25 mg/mL). The material was injected into the subcutaneous tissue of an adult Sprague-Dawley rat, harvested at 8 weeks, and evaluated grossly and histologically. The specimens were paraffin embedded, sectioned on a microtome, and stained with hematoxylin and eosin.

Results:

In vivo analysis of the TB-HA hydrogels at 8 weeks revealed that they were resistant to degradation. Histological analysis revealed no evidence of rejection or tissue inflammatory response.

Conclusions:

Novel enzymatic cross-linking of HA enables the development of a versatile new biomaterial that can be used for soft-tissue augmentation. Preliminary in vivo analysis in an immunocompetent rat model revealed that the hydrogel material resisted degradation and did not elicit a host inflammatory response.

Hoarseness-causes and treatments

BACKGROUND

Hoarseness (dysphonia) is the reason for about 1% of all consultations in primary care. It has many causes, ranging from self-limited laryngitis to malignant tumors of the vocal cords.

METHODS

This review is based on literature retrieved by a selective search in PubMed employing the terms "hoarseness," "hoarse voice," and "dysphonia," on the relevant guideline of the American Academy of Otolaryngology -Head and Neck Surgery, and on Cochrane reviews.

RESULTS

Hoarseness can be caused by acute (42.1%) and chronic laryngitis (9.7%), functional vocal disturbances (30%), and benign (10.7-31%) and malignant tumors (2.2-3%), as well as by neurogenic disturbances such as vocal cord paresis (2.8-8%), physiologic aging of the voice (2%), and psychogenic factors (2-2.2 %). Hoarseness is very rarely a manifestation of internal medical illness. The treatment of hoarseness has been studied in only a few randomized controlled trials, all of which were on a small scale. Voice therapy is often successful in the treatment of functional and organic vocal disturbances (level 1a evidence). Surgery on the vocal cords is indicated to treat tumors and inadequate vocal cord closure. The only entity causing hoarseness that can be treated pharmacologically is chronic laryngitis associated with gastro-esophageal reflux, which responds to treatment of the reflux disorder. The empirical treatment of hoarseness with antibiotics or corticosteroids is not recommended.

CONCLUSION

Voice therapy, vocal cord surgery, and drug therapy for appropriate groups of patients with hoarseness are well documented as effective by the available evidence. In patients with risk factors, especially smokers, hoarseness should be immediately evaluated by laryngos - copy.

Tissue engineering-based therapeutic strategies for vocal fold repair and regeneration

Vocal folds are soft laryngeal connective tissues with distinct layered structures and complex multicomponent matrix compositions that endow phonatory and respiratory functions. This delicate tissue is easily damaged by various environmental factors and pathological conditions, altering vocal biomechanics and causing debilitating vocal disorders that detrimentally affect the daily lives of suffering individuals. Modern techniques and advanced knowledge of regenerative medicine have led to a deeper understanding of the microstructure, microphysiology, and micropathophysiology of vocal fold tissues. State-of-the-art materials ranging from extracecullar-matrix (ECM)-derived biomaterials to synthetic polymer scaffolds have been proposed for the prevention and treatment of voice disorders including vocal fold scarring and fibrosis. This review intends to provide a thorough overview of current achievements in the field of vocal fold tissue engineering, including the fabrication of injectable biomaterials to mimic in vitro cell microenvironments, novel designs of bioreactors that capture in vivo tissue biomechanics, and establishment of various animal models to characterize the in vivo biocompatibility of these materials. The combination of polymeric scaffolds, cell transplantation, biomechanical stimulation, and delivery of antifibrotic growth factors will lead to successful restoration of functional vocal folds and improved vocal recovery in animal models, facilitating the application of these materials and related methodologies in clinical practice.

Adverse Reaction to Hyaluronic Acid Injection Laryngoplasty: A Case Report

INTRODUCTION

Injection laryngoplasty using hyaluronic acid is a safe procedure commonly performed on patients with glottic insufficiency.

STUDY DESIGN

This is a descriptive study of a case of adverse reaction to hyaluronic acid in a patient who underwent injection laryngoplasty for the treatment of unilateral vocal cord paralysis.

DISCUSSION

The patient was treated with antibiotics and corticosteroids and had a full recovery. The authors recommend close observation following injection laryngoplasty using hyaluronic acid and diligent investigation of persistent postoperative laryngopharyngeal symptoms.

The use of injectable calcium hydroxylapatite in the surgically pretreated larynx with glottal insufficiency

OBJECTIVES/HYPOTHESIS

To evaluate the efficacy of vocal fold (VF) augmentation with calcium hydroxylapatite (CaHA) microspheres in the surgically pretreated larynx with glottal insufficiency.

STUDY DESIGN

Prospective clinical pilot study.

METHODS

After several prior reconstructive attempts (following tumor resection, VF paralysis, in sulcus vocalis, and VF scarring), CaHA was injected under general anaesthesia using a transoral microlaryngoscopic approach in 10 patients with residual glottal insufficiency ≤1.5 mm. The postinterventional result was assessed after 1 day, and 1 and 3 months. Evaluation of augmentation comprised intraoperative video/photo documentation, pre-/postoperative videolaryngostroboscopy, as well as established subjective and objective voice function diagnostics (Grade, Roughness, Breathiness [GRB] Scale; Voice Handicap Index; voice range profile; and acoustic-aerodynamic analysis).

RESULTS

In the pretreated VF with no or minimal lamina propria remaining, the exact placement of CaHA was not possible due to unpredictable propagation into the scarred tissue. The results showed an insufficient postoperative augmentation. Accordingly, the voice function did not improve. However, a significant increase of the vocal range from 6.2 ± 3.2 to 8.7 ± 3.9 semitones was observed in the speaking voice profile (P =.02). All other acoustic and aerodynamic parameters remained on the whole unchanged; the slight differences between pre- and postoperative findings were not significant.

CONCLUSIONS

The application of CaHA in the surgically pretreated scarred larynx is not reliable to achieve a sufficient glottal closure and a satisfactory improvement of voice. Though CaHA is a welcome addition to our armamentarium against glottal insufficiency, the suitability for augmentation of scar tissue in the larynx must be considered carefully in each individual case.

LEVEL OF EVIDENCE

4 Laryngoscope, 127:1125-1130, 2017.

Factors Associated With Attrition in Randomized Controlled Trials of Vocal Rehabilitation: Systematic Review and Meta-Analysis

OBJECTIVES/HYPOTHESIS

This study aimed to determine the dropout rates and the reasons for dropout in randomized clinical trials of vocal rehabilitation.

STUDY DESIGN

This study used systematic review and meta-analysis (CRD42013003807).

METHODS

We included randomized controlled trials for voice disorders. In June 2015, we searched the following databases: MEDLINE, EMBASE, Cochrane, Clinical Trials, and AJSLP. The titles and abstracts or full texts of articles were independently analyzed by two reviewers. Study quality was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) scale. Our initial research base included more than 8491 articles.

RESULTS

A total of 51 articles were obtained using our eligibility criteria. The low-quality studies evaluated had higher dropout rates (odds ratio: 3.3, 95% confidence interval: 1.04-12.9). Studies with healthy patients (45%) or vocal training versus no training (25%) also had higher dropout rates. Methodological issues seemed to have a greater influence on the dropout rates of the studies included in the co-occurrence matrix.

CONCLUSIONS

Dropout rates of approximately 15% occur in randomized clinical trials of speech therapy when assessed by the Grading of Recommendations Assessment, Development and Evaluation. Studies with lower methodological quality had higher patient loss rates. Methodological and clinical reasons accounted for the highest dropout rates in the studies included in this meta-analysis.

Histologic Characterization of Rat Vocal Fold Scarring

This study aimed to clarify the characteristics of rat vocal fold scarring by examining the alteration of key components in the extracellular matrix: hyaluronic acid, collagen, and fibronectin. Under monitoring with a 1.9-mm-diameter telescope, unilateral vocal fold stripping was performed, and larynges were harvested at 2, 4, 8, and 12 weeks after operation. The vocal folds were histologically analyzed with Alcian blue stain, trichrome stain, and immunofluorescence of collagen type I, collagen type III, and fibronectin. The scarred vocal folds showed less hyaluronic acid and more collagen types I and III than did the controls at all time points. Type III was stable for 12 weeks, while type I declined until 8 weeks and thereafter remained unchanged. Fibronectin increased for 4 weeks and then decreased; it was close to the control level at 8 and 12 weeks. These results suggest that the tissue remodeling process in scarred vocal folds slows down around 2 months after wounding.

Autologous grafts for treatment of vocal sulcus and atrophy

Objectives

To obtain complete glottal closure, and evaluate improvement of vocal fold vibration amplitude and vocal quality in patients with sulcus vocalis.

Methods

Autogenous fat and/or fascia augmentation was used in 34 patients with sulcus vocalis. Mean follow-up time was 1 year. The perceptual acoustic and phonatory functions and videolaryngostroboscopic data were evaluated before and after the procedure.

Results

Most of the individuals reported an improvement of vocal quality, a complete glottal closure, an enhancement of mucosal wave excursion, and significant results of acoustic perceptual and phonatory functions after the surgery.

Conclusion

Fat and fascia injections are effective autogenous implants and should be considered options in the treatment of patients with sulcus vocalis and vocal fold atrophy.

"Finding a Voice": Imaging Features after Phonosurgical Procedures for Vocal Fold Paralysis

Altered communication (hoarseness, dysphonia, and breathy voice) that can result from vocal fold paralysis, secondary to numerous etiologies, may be amenable to surgical restoration. In this article, both traditional and cutting-edge phonosurgical procedures targeting the symptoms resulting from vocal fold paralysis are reviewed, with emphasis on the characteristic imaging appearances of various injectable materials, implants, and augmentation procedures used in the treatment of vocal fold paralysis. In addition, complications of injection laryngoplasty and medialization laryngoplasty are illustrated. Familiarity with the expected imaging changes following treatment of vocal fold paralysis may prevent the misinterpretation of posttreatment changes as pathology. Identifying common complications related to injection laryngoplasty and localization of displaced implants is crucial in determining specific management in patients who have undergone phonosurgical procedures for the management of vocal fold paralysis.

Efficiency and durability of hyaluronic acid of different particle sizes as an injectable material for VF augmentation

CONCLUSION

The results of the present investigation suggest that modification of HA could improve efficiency and durability in augmentation laryngoplasty.

OBJECTIVES

Injection laryngoplasty (IL) is one of the most suitable options for treatment of glottic insufficiency, which is caused by vocal fold (VF) paralysis, atrophy, or scarring. Hyaluronic acid (HA) is a widely used material for VF injection. This study was intended to evaluate the durability and efficiency of HA of different particle sizes for VF augmentation.

METHODS

Three types of HA, Restylane®, monophasic low-viscosity, and unequal particle-sized middle-viscosity HA were injected into the left VF of three groups with eight rabbits each.

RESULTS

After 6 and 10 weeks, the injected site was evaluated endoscopically, histologically, radiologically, and functionally. None of the 24 rabbits showed any signs of respiratory distress. Computed tomography (CT) images and endoscopic evaluation revealed sufficient augmented volume of the injected VF in all treated groups 6 weeks after the injection. Histological data at week 10 showed that unequal particle-sized HA did not migrate from its original injection site, while other HAs migrated to the periphery of the arytenoid cartilage. Videokymographic analysis showed more favorable vibrations of unequal particle-sized HA injected VF mucosa 10 weeks post-injection, compared to the other treatment groups.

Viscoelasticity of hyaluronic acid-gelatin hydrogels for vocal fold tissue engineering

Crosslinked injectable hyaluronic acid (HA)-gelatin (Ge) hydrogels have remarkable viscoelastic and biological properties for vocal fold tissue engineering. Patient-specific tuning of the viscoelastic properties of this injectable biomaterial could improve tissue regeneration. The frequency-dependent viscoelasticity of crosslinked HA-Ge hydrogels was measured as a function of the concentration of HA, Ge, and crosslinker. Synthetic extracellular matrix hydrogels were fabricated using thiol-modified HA and Ge, and crosslinked by poly(ethylene glycol) diacrylate. A recently developed characterization method based on Rayleigh wave propagation was used to quantify the frequency-dependent viscoelastic properties of these hydrogels, including shear storage and loss moduli, over a broad frequency range; that is, from 40 to 4000 Hz. The viscoelastic properties of the hydrogels increased with frequency. The storage and loss moduli values and the rate of increase with frequency varied with the concentrations of the constituents. The range of the viscoelastic properties of the hydrogels was within that of human vocal fold tissue obtained from in vivo and ex vivo measurements. Frequency-dependent parametric relations were obtained using a linear least-squares regression. The results are useful to better fine-tune the storage and loss moduli of HA-Ge hydrogels by varying the concentrations of the constituents for use in patient-specific treatments.

Imaging appearance of dextranomer/hyaluronic acid copolymer implant injections for treatment of velopharyngeal insufficiency

BACKGROUND AND PURPOSE

Dextranomer/hyaluronic acid copolymer implants are used in treating velopharyngeal insufficiency. These posterior nasopharyngeal implants can be mistaken for pathologic conditions such as retropharyngeal abscess on imaging. We studied the imaging appearance of dextranomer/hyaluronic acid copolymer implants in patients treated for velopharyngeal insufficiency.

MATERIALS AND METHODS

A consecutive series of patients with velopharyngeal insufficiency treated with dextranomer/hyaluronic acid copolymer were included in this study. Data on patient characteristics and volume of dextranomer/hyaluronic acid copolymer injected were obtained. Postoperative imaging characteristics on plain radiography, CT, and MR imaging were assessed. The imaging appearance of postoperative complications was determined.

RESULTS

Sixteen patients were included in this study. Seven patients underwent postoperative plain radiographs, 5 patients underwent CT, and 9 patients underwent MR imaging. Plain radiographs demonstrated soft-tissue swelling in the retropharyngeal space, which resolved at 1 month. On CT, dextranomer/hyaluronic acid copolymer implants appeared as bilateral nasopharyngeal soft-tissue masses isoattenuated to hypoattenuated relative to muscle in 80% (4/5) of patients. On MR imaging, dextranomer/hyaluronic acid copolymer implants appeared as bilateral nasopharyngeal soft-tissue masses that were isointense to muscle on T1 (8/9, 88.9%) and hyperintense to muscle on T2 (8/9, 88.9%) and demonstrated no restricted diffusion (4/4, 100.0%) or peripheral enhancement (7/7, 100.0%).

CONCLUSIONS

The normal postoperative findings of posterior nasopharyngeal dextranomer/hyaluronic acid copolymer injection on MR imaging is characterized by the presence of bilateral nasopharyngeal soft-tissue masses that are isointense to muscle on T1 and hyperintense on T2, with no restricted diffusion or peripheral enhancement. Velopharyngeal dextranomer/hyaluronic acid copolymer implants are iso- to hypoattenuated to muscle on CT and are not visible radiographically once associated implantation-related swelling has resolved.

Transnasal injection laryngoplasty

OBJECTIVES

The objective of this study was to evaluate the role of transnasal fiber-optic injection laryngoplasty in the treatment of glottic insufficiency.

METHODS

Video recordings of 16 patients who underwent fiber-optic injection laryngoplasty for the treatment of glottic insufficiency were reviewed. Outcome measures included perceptual evaluation using the GRBAS (grading, roughness, breathiness, asthenia, straining) classification, laryngeal videostroboscopy, and frame-by-frame analysis to assess the extent, shape, and duration of glottic closure.

RESULTS

Nine patients were ultimately included in this study. Their mean age was 66.2 years, with 7 men and 2 women. The most common symptoms were dysphonia and aspiration, and the most common diagnosis was vocal fold paralysis. Patients underwent transnasal fiber-optic injection laryngoplasty with hyaluronic acid as a filling material (0.2-0.8 mL). The procedure was well tolerated by all patients, with improvement in the phonatory symptoms and aspiration in 66.66% and 50% of patients, respectively. There were significant decreases in the mean scores of all perceptual parameters (P<.05 for all). All subjects had glottal gap preoperatively that was closed completely in 66.66% and reduced to <2 mm in 33.33%. The mean closed quotient significantly increased from 0.10 to 0.51 (P<.05).

CONCLUSIONS

Transnasal fiber-optic injection laryngoplasty is a safe procedure well tolerated by patients with good results.

An in vivo study of composite microgels based on hyaluronic acid and gelatin for the reconstruction of surgically injured rat vocal folds

PURPOSE The objective of this study was to investigate local injection with a hierarchically microstructured hyaluronic acid-gelatin (HA-Ge) hydrogel for the treatment of acute vocal fold injury using a rat model. METHOD Vocal fold stripping was performed unilaterally in 108 Sprague-Dawley rats. A volume of 25 μl saline (placebo controls), HA-bulk, or HA-Ge hydrogel was injected into the lamina propria (LP) 5 days after surgery. The vocal folds were harvested at 3, 14, and 28 days after injection and analyzed using hematoxylin and eosin staining and immunohistochemistry staining for macrophages, myofibroblasts, elastin, collagen type I, and collagen type III. RESULTS The macrophage count was statistically significantly lower in the HA-Ge group than in the saline group (p < .05) at Day 28. Results suggested that the HA-Ge injection did not induce inflammatory or rejection response. Myofibroblast counts and elastin were statistically insignificant across treatment groups at all time points. Increased elastin deposition was qualitatively observed in both HA groups from Day 3 to Day 28, and not in the saline group. Significantly more elastin was observed in the HA-bulk group than in the uninjured group at Day 28. Significantly more collagen type I was observed in the HA-bulk and HA-Ge groups than in the saline group (p < .05) at Day 28. The collagen type I concentration in the HA-Ge and saline groups was found to be comparable to that in the uninjured controls at Day 28. The concentration of collagen type III in all treatment groups was similar to that in uninjured controls at Day 28. CONCLUSION Local HA-Ge and HA-bulk injections for acute injured vocal folds were biocompatible and did not induce adverse response.

Treatment Outcomes of Injection Laryngoplasty Using Cross-Linked Porcine Collagen and Hyaluronic Acid

Objective

To investigate the treatment outcomes and prognostic factors of injection laryngoplasty (IL) using cross-linked porcine collagen (PC) and hyaluronic acid (HA) in unilateral vocal fold paralysis (UVFP).

Study Design

Case series with chart review.

Setting

A tertiary teaching hospital.

Subjects and Methods

This study reviewed 60 consecutive patients with UVFP who underwent IL with PC (n = 33) or HA (n = 27). Objective evaluations included maximal phonation time (MPT) and 10-item voice handicap index (VHI-10). Kaplan-Meier method was applied to evaluate the subjective treatment outcomes according to the patients’ self-assessment of symptom recurrence via chart review for the follow-up period of 15 months. Log-rank tests were applied to evaluate the association between clinical factors and subjective treatment outcomes.

Results

Objective outcome measurements revealed significantly improved MPT and VHI-10 at 1, 3, and 6 months posttreatment, with nonsignificant differences between the PC and HA groups. Subjective treatment outcomes also revealed a nonsignificant difference between the 2 groups. The median symptom-free durations were 10.9 and 14.4 months for the PC and HA groups, respectively. Subsequent analyses failed to identify prognostic significance of sex, time to treatment, etiology, side, injection approaches, and the presence of aspiration. No significant adverse effects occurred during the follow-up period.

Conclusion

This study demonstrated comparable subjective and objective improvements following IL using PC or HA in patients with UVFP. No significant prognostic factor of IL was discovered in the present research. Porcine collagen and HA as medium duration materials might play a role in the future of IL.

Prospective Evaluation of Office-Based Injection Laryngoplasty with Hyaluronic Acid Gel

Objectives:

The role of Juvederm Ultra Plus hyaluronic acid gel for use in injection laryngoplasty has not been well examined. The aim of this study was to prospectively assess the safety and clinical effectiveness of office-based injection laryngoplasty of Juvederm Ultra Plus gel in patients with glottic insufficiency.

Methods:

Thirty patients met the criteria for study inclusion and were treated with unsedated office-based injection laryngoplasty of Juvederm Ultra Plus gel over a 20-month period. The preinjection acoustic and aerodynamic measures, Voice Handicap Index, Glottal Function Index, and Dysphonia Severity Index were compared with values recorded at 1 and 4 months after injection.

Results:

Data for 27 patients were available for follow-up analysis at 1 month, and 12 patients' data were available at 4 months. Significant improvements, compared to preinjection levels (p < 0.02), were shown in all outcome measures at 1 and 4 months. One patient required intravenous steroid therapy for delayed glottic inflammation that resolved without permanent sequelae.

Conclusions:

The injection of Juvederm Ultra Plus gel is a relatively safe procedure that allows for short-term improvements in objective and subjective outcome measures of vocal function in patients with glottic insufficiency, provided the surgeon remains alert to the possibility of postprocedural injection site inflammation.

[Treatment of glottal gap]

Glottal gaps can be either physiological or pathological. The latter are multifactorial, predominantly organic in origin and occasionally functional. Organic causes include vocal fold paralysis or scarring, as well as a deficiency or excess of tissue. In addition to loss of the mucosal wave, the degree of hoarseness is primarily determined by the circumferential area of the glottal gap. It is thus important to quantify the extent of glottal insufficiency. Although a patient's symptoms form the basis for treatment decisions, these may be subjective and inadequately reflected by the results of auditory-perceptual evaluation, voice analysis and voice performance tests. The therapeutic approach should always combine phonosurgery with conventional voice therapy methods. Voice therapy utilises all the resources made available by the sphincter model of the aerodigestive tract and knowledge on the mechanism of voice production. The aim of phonosurgery is medialization, reconstruction or reinnervation by injection laryngoplasty or larynx framework surgery. These different methods can be combined and often applied directly after vocal fold surgery (primary reconstruction). In conclusion, the techniques described here can be effectively employed to compensate for glottal gaps.