Surgical Management of Sulcus Vocalis and Vocal Fold Scarring

Evaluating Interventions for Sulcus Vocalis or Vocal Fold Scar: A Systematic Review and Meta-analysis

BACKGROUND

Sulcus vocalis reflects varying degrees of vocal cord lamina propria (LP) damage. Many interventions have been discussed in the literature for addressing sulcus vocalis, but there is no universally accepted gold standard for its management.

AIM

We aim in our study to collectively evaluate the effectiveness of different relevant interventions in the literature used for sulcus vocalis or vocal fold scar.

METHODS

We searched five electronic databases to collect all relevant studies. Records were screened for eligibility. Data were extracted from the included studies independently. Our continuous outcomes were pooled in our single-arm meta-analysis as mean change (MC) and with 95% confidence interval (CI).

RESULTS

Our systematic review and meta-analysis included 43 studies encompassing 1302 patients. The jitter parameter indicated that laser degeneration and LP regeneration/scar degradation led to the highest improvements compared to their baseline, with pooled MC of -0.897 and -0.893, respectively. Graft interposition showed a MC of -0.848, while medialization and dissection had less pronounced changes at -0.200. Shimmer parameter results were similar, with medialization and laser degeneration leading to MC of -2.129 and -2.123, while LP regeneration/scar degradation and graft interposition showed smaller changes MC -1.530 and -1.217. For the noise-to-harmonic ratio (NHR) parameter, LP regeneration/scar degradation demonstrated MC = -0.028. In aerodynamics outcomes, graft interposition and LP regeneration/scar degradation showed the highest MCs in mean phonatory time (MPT) (4.214 and 3.467, respectively). Endoscopic outcomes for mucosal wave showed high improvements in medialization and graft interposition (MC = 10.40 and 10.18, respectively). Perceptual outcomes favored graft interposition in various parameters, while laser degeneration performed well in most categories. Graft interposition and LP regeneration/scar degradation had a high voice handicap index (VHI) (MC = -27.195 and -19.269, respectively).

CONCLUSION

Laser degeneration and LP regeneration/scar degradation were particularly effective in improving acoustic parameters. In aerodynamics, graft interposition and LP regeneration/scar degradation improved vocal efficiency compared to their baselines. Medialization and laser degeneration had the largest impact compared to their baseline on shimmer and MPT. Endoscopic assessments showed that medialization and graft interposition had high improvement in mucosal waves, and perceptual outcomes were generally high with graft interposition and laser degeneration.

Treatment efficacy of 532-nm diode laser glottoplasty in patients with sulcus vocalis: a prospective study

PURPOSE

This study prospectively assessed the efficacy and safety of 532-nm diode laser glottoplasty in patients with sulcus vocalis.

METHODS

A prospective human trial was performed from August 2016 to September 2021. 532-nm diode laser glottoplasty was performed in 30 consecutive patients with sulcus vocalis who suffered from voice problems. Patients underwent acoustic aerodynamic, perceptual, stroboscopic, and Voice Handicap Index-10 (VHI-10) evaluations before and 1, 6, and 12 months after laser glottoplasty.

RESULTS

Most subjective parameters showed significant improvement (P < 0.05) at 6 months after laser glottoplasty and remained stable at 12 months. Most objective parameters showed significant improvement (P < 0.05) at 12 months after laser glottoplasty. Complications during follow-up included mild vocal fold vibration reduction in 3.3% of patients (1/30) and persistent vocal fold edema in 3.3% of patients (1/30).

CONCLUSIONS

Statistically significant voice improvement at 12 months after 532-nm diode laser glottoplasty was achieved without serious complications.

Efficacy of platelet-rich plasma (PRP) in benign vocal fold lesions: a systematic review and meta-analysis

OBJECTIVES

To evaluate the efficacy of platelet-rich plasma (PRP) in benign vocal fold lesions.

METHODS

MEDLINE, Cochrane Central, Web of Science, and Scopus databases were searched in April 2023 for relevant clinical trials. Inclusion criteria were clinical trials evaluating the efficacy of PRP in benign vocal fold lesions. We conducted a comparative double-arm analysis using the pooled mean difference (MD) and 95% confidence interval (CI). Outcomes of interest included the vocal handicap index (VHI), the Jitter and Shimmer percentages, and the noise-to-harmonic ratio (NHR).

RESULTS

Six studies matched the inclusion criteria. The pooled analysis shows that PRP was associated with significantly lower VHI scores compared with the control (MD = - 5.06, p < 0.01). Regarding the Jitter percentage, the PRP group was not superior to the control group at 2 and 4 weeks. However, the results revealed that PRP significantly reduced the Jitter percentage at 3 months (MD = - 0.61, p = 0.0008). The overall analysis favored the PRP arm significantly (p < 0.001). As for the Shimmer percentage, the combined effect estimate favored the PRP group (MD = - 1.22, p = 0.002). Subgroup analysis according to the time did not reveal any significant differences between studies at 2 weeks, 4 weeks, and 3 months. The analysis of the NHR outcome revealed a significant difference between both groups (MD = -1.09, p = 0.01). However, at 4 weeks, the treatment group had a significantly lower NHR % compared to the control group (MD = - 0.61, p = 0.02). There was no significant difference at 3 months (MD = - 2.14, p = 0.14).

CONCLUSIONS

Platelet-rich plasma is effective in reducing VHI scores, Jitter and Shimmer percentages, and NHR values. This effect is more evident after follow-up, especially 3 months.

Platelet-rich plasma in treatment of scar, atrophy, and sulcus: Short- and long-term results

Objective

Platelet-rich plasma (PRP) is rich in growth factors and is easily obtained from blood samples. Long-term data after PRP injection into the larynx should be improved. This study reports the short-term (3 months) and long-term (12 months) voice results after PRP injection.

Materials and Methods

Sixty-three patients with scars (n = 34), sulcus vocalis (n = 17), recalcitrant nodules (n = 5), atrophy (n = 4), or a combination of these (n = 3) were included (158 injections; median follow-up = 12.3 months). Stroboscopy, voice handicap index (VHI-10), and cepstral spectral index of dysphonia (CSID) before and after treatment (3 months) and at 12 months were tabulated.

Results

VHI-10 changed from 19.5 to 14 at 3 months and 21 to 15 in the long term. The CSID scores improved from 31 to 21 in the short term and 31 to 26 in the long term (p < 0.001, paired t-test). Patients reported improved vocal effort and stamina with slight VHI or CSID score changes. Stroboscopy revealed improved closure and mucosal waves. Patients with severe dysphonia were less likely to improve compared to those with mild to moderate dysphonia. Some patients showed short-term improvements and then deteriorated back to baseline CSID over time (p < .05, paired t-test).

Conclusion

Both short- and long-term improvements in voice following PRP injection have been reported. Patients with mild-to-moderate dysphonia had better outcomes. PRP injection is an alternative treatment for patients with mild-to-moderate dysphonia due to vocal fold scarring, sulcus, and atrophy.

Level of evidence

II Prospective case series treatment.

Assessment of Subjective and Objective Voice Analysis According to Types of Sulcus Vocalis

INTRODUCTION

Sulcus vocalis (SV) subtypes are difficult to diagnose. Non-invasive techniques are sometimes not feasible in the diagnosis. The study aims to demonstrate the effectiveness and applicability of objective and subjective voice analysis combined with videolaryngostroboscopic examination (VLS) in the diagnosis of SV types.

MATERIAL AND METHODS

This is a retrospective study that includes patients who presented to Phoniatric outpatient clinic with complaints related to voice and diagnosed with SV on VLS examination between 2017-2020. The SV type was determined based on VLS findings and the patients were categorized into respective groups. Between- and within-group assessment of objective and subjective voice analysis of SV types was conducted.

RESULTS

47 patients were included in the study; Type I, Type II, Type III SV patients were 16, 17, and 14 in number, respectively. Fundamental frequency (F0) and Shimmer (%) values were significantly high in Type II and III SV cases, whereas the Maximum Phonation Time (MPT) was significantly low. GRBAS, Voice Handicap Index -10 (VHI-10), Reflux Symptom Index (RSI) scores were statistically significantly high in pathological SV and Voice Related Quality of Life (V-RQOL) scores were low. A moderate correlation between VHI-10 and V-RQOL and between RSI and V-RQOL was detected.

CONCLUSIONS

Objective and subjective voice analysis in Type II and III SV show a significant difference compared to Type I SV. The use of objective and subjective voice analysis combined with VLS examination can be helpful in the diagnosis of SV types.

Sulcus Vocalis and Benign Vocal Cord Lesions: Is There Any Relationship?

BACKGROUND

Sulcus vocalis (SV) is a longitudinal groove in the free edge of the true vocal cord. It may impair phonation with incomplete glottic closure, phonasthenia and hoarseness. This study aims to detect a correlation between benign vocal cord lesions and the incidence of the SV.

METHODS

A retrospective study was carried out on patients who underwent transoral surgery due to benign vocal fold lesions and were selected according to strict criteria. Patients were divided into a group with sulcus vocalis (Group wSV) and a group without sulcus vocalis (Group w/oSV). The possible correlations between variables were assessed by the Pearson chi-square test (p < 0.05).

RESULTS

The study included 232 vocal cord lesions in 229 patients: 62.88% were females whose mean age was 46.61 ± 14.04. The most frequent diseases were polyps (37.94%), nodules (18.53%) and Reinke's edema (21.12%). Statistically significant relationships were found between age and SV (p-value 0.0005) and between mild dysplasia and SV (p-value 0.03).

CONCLUSIONS

This study did not detect a cause-effect relationship between SV and benign vocal fold lesions. SV within vocal fold lesions is more common in younger patients, suggesting a congenital nature of SV. In conclusion, in the case of a benign vocal fold lesion, a possible SV should be considered and researched to provide the patient the best healthcare.

Safety of Platelet-Rich Plasma Subepithelial Infusion for Vocal Fold Scar, Sulcus, and Atrophy

OBJECTIVE

To demonstrate the safety profile of platelet-rich plasma (PRP) as an injectable therapeutic for the treatment of vocal fold scarring and atrophy.

METHODS

Preliminary report on a prospective clinical trial of patients with vocal fold scar or atrophy undergoing unilateral vocal fold subepithelial infusion with autologous PRP. Enrolled patients underwent four subepithelial injections spaced 1 month apart. Adverse events were assessed peri and post-injection at each session. Patient-reported outcomes were collected at every visit using the Voice Handicap Index-10 (VHI-10) and Vocal Fatigue Index (VFI) questionnaires.

RESULTS

Twelve patients underwent unilateral vocal fold injection with autologous PRP prepared according to Eclipse PRP® system protocol. Forty-three injections were performed using a peroral or percutaneous approach. An average of 1.57 ± 0.4 cc (range 0.6-2.0 cc) injectate was used. All patients tolerated the procedure without difficulty or peri-procedural complications. The average duration of follow-up was 3.6 ± 1.8 months. No significant inflammatory reactions or adverse events were seen to date. There was statistically significant improvement in patient-reported outcomes at the 3 month follow up (n = 9) follow-up (mean ΔVHI-10 = 10.8, p < 0.001, mean ΔVFI = 18.9, p = 0.01, t test, paired two sample for means, two-tail). All nine patients who completed the series of four injections subjectively (yes/no) reported they were satisfied with the results.

CONCLUSION

This prospective study cohort demonstrated a favorable safety profile, with no adverse events or peri-procedural complications. Subjective improvements in vocal quality and reduction in vocal fatigue need to be clinically correlated with further study.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:647-653, 2023.

Effect of Occupational Noise Exposure on the Prevalence of Benign Vocal Fold Lesions: A Nationwide Population-Based Study

OBJECTIVES

Voice abuse in noisy environments can result in voice disorders. However, insufficient studies have sought to differentiate vocal cord lesions through laryngoscopic examinations among workers in noisy environments. This study investigated the relationship between a history of noise exposure in the workplace and benign vocal fold lesions (BVFLs).

METHODS

We used Korea National Health and Nutrition Examination Survey data from 2010 to 2012. The chi-square test was used to compare characteristics between two groups according to the presence or absence of BVFLs. To investigate the association between BVFLs and noise exposure in the workplace, we calculated adjusted odds ratios and 95% confidence intervals (CIs) using multiple logistic regression analysis.

RESULTS

In total, 10,170 participants with available laryngoscopy.

RESULTS

were enrolled. Smoking history, hypertension, diabetes, and exposure to noise for more than 3 months at the workplace were significantly more common in participants with BVFLs. After adjusting for age, sex, smoking, drinking, obesity, hypertension, diabetes, income, education, and occupation as confounders, we confirmed that BVFLs were 1.52 times more likely (95% CI, 1.157-1.990) to occur in individuals with occupational noise exposure.

CONCLUSION

Working in a noisy environment could induce BVFLs in workers through voice abuse. Social recognition that a noisy environment is a risk factor for BVFLs needs to be improved, and preventive measures should be implemented.

Effects of Different Voice Rest on Vocal Function After Microlaryngeal Surgery: A Systematic Review and Meta-Analysis

OBJECTIVES

To compare the results of a voice handicap index (VHI) scale and acoustic parameters in patients who underwent microlaryngeal surgery followed by either short-duration (voice rest for <7 days) or long-duration (≥7 days) voice rest.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The PubMed, Embase, and Cochrane Library databases were systematically searched for articles published before March 1, 2021. Randomized controlled trials (RCTs) that measured the voice outcomes of patients after different durations and extents of postoperative voice restriction were included in the meta-analysis.

RESULTS

Four RCTs comprising 112 patients were included in the quantitative meta-analysis. Compared with the long-duration voice rest group, the short-duration group exhibited comparable VHI scores (mean difference [MD], -7.01; 95% CI, -16.12 to 2.09; p = 0.13), maximum phonation time (MD, -2.58; 95% CI, -5.42 to 0.26; p = 0.07), and acoustic variables of jitter (MD, -1.25; 95% CI, -3.43 to 0.94; p = 0.26) and shimmer (MD, -0.79; 95% CI, -2.08 to 0.51; p = 0.24). Subgroup analysis for benign pathology and cold instruments studies demonstrated significantly better VHI scores (MD, -14.45; 95% CI, -26.19 to -2.72; p = 0.02 and MD, -15.98; 95% CI, -28.52 to -3.44; p = 0.01, respectively) in the short-duration group.

CONCLUSIONS

The limited evidence does not demonstrate benefit in voice outcomes from long-duration voice rest and suggests potential unfavorable effects on compliance and quality of life, providing a rationale for short-duration voice rest after microlaryngeal surgery. More studies are required to determine the optimal duration and extent of postoperative voice rest.

LEVEL OF EVIDENCE

1 Laryngoscope, 133:154-161, 2023.

Effects of Sulcus Vocalis Depth on Phonation in Three-Dimensional Fluid-Structure Interaction Laryngeal Models

Sulcus vocalis is an indentation parallel to the edge of vocal fold, which may extend into the cover and ligament layer of the vocal fold or deeper. The effects of sulcus vocalis depth d on phonation and the vocal cord vibrations are investigated in this study. The three-dimensional laryngeal models were established for healthy vocal folds (0 mm) and different types of sulcus vocalis with the typical depth of 1 mm, 2 mm, and 3 mm. These models with fluid-structure interaction (FSI) are computed numerically by sequential coupling method, which includes an immersed boundary method (IBM) for modelling the glottal airflow, a finite-element method (FEM) for modelling vocal fold tissue. The results show that a deeper sulcus vocalis in the cover layer decreases the vibrating frequency of vocal folds and expands the prephonatory glottal half-width which increases the phonation threshold pressure. The larger sulcus vocalis depth makes vocal folds difficult to vibrate and phonate. The effects of sulcus vocalis depth suggest that the feature such as phonation threshold pressure could assist in the detection of healthy vocal folds and different types of sulcus vocalis.

Short-Term Voice Improvement after Repeated Office-Based Platelet-Rich Plasma PRP Injection in Patients with Vocal Fold Scar, Sulcus, and Atrophy

INTRODUCTION

Improving the voice of patients with vocal atrophy, scar, and sulcus vocalis remains challenging. Platelet-rich plasma (PRP) is an autologous biological suitable for regenerative medicine. Office-based injections of PRP may serve as a source of improved wound healing.

MATERIALS AND METHODS

Thirty two office based injections of PRP were performed in 14 patients with scar, sulcus, and vocal atrophy (12 scars, 1 sulcus, and 1 atrophy). PRP was prepared using 20 cc blood draw and double centrifugation method. Injection laryngoplasty was performed using trans cervical or indirect trans oral technique (10 trans cervical, 22 trans-oral). Volume of PRP use was 0.5-0.7 cc per side. Injections varied from 1 to 3 injections at monthly intervals. Videostroboscopy, Voice Handicap Index (VHI-10), and an objective analysis of the voice using Cepstral Peak Prominence (Cepstral Spectral Index of Dysphonia) were recorded. An expert rater speech pathologist rated the audio and stroboscopy results.

RESULTS

Median follow-up was 15 months. No patients were made worse. The mean VHI-10 before the injection was 23. VHI-10 after the injection was 12.5 (P < 0.01). The mean Cepstral Spectral Index of Dysphonia score for CAPE-V sentence was 42.5 before the injection and 23.5 (P < 0.01) after the injection. The expert rater thought the post treatment was better (9/14 acoustic, 10/14 stroboscopy). Eleven of the 14 patients thought the intervention was worthwhile to repeat. The other 3 patients thought the improvement was transient.

CONCLUSION

Office PRP injection into the vocal fold of patients with scar, sulcus, and atrophy may result in short term voice improvements. It is a biological worth considering.

A tissue-specific, injectable acellular gel for the treatment of chronic vocal fold scarring

Gel-based injectable biomaterials have significant potential for treating vocal fold defects such as scarring. An ideal injectable for vocal fold lamina propria restoration should mimic the microenvironment of the lamina propria to induce scarless wound healing and functional tissue regeneration. Most current synthetic or natural injectable biomaterials do not possess the same level of complex, tissue-specific constituents as the natural vocal fold lamina propria. In this study we present a newly-developed injectable gel fabricated from decellularized bovine vocal fold lamina propria. Blyscan assay and mass spectrometry indicated that the vocal fold-specific gel contained a large amount of sulfated glycosaminoglycans and over 250 proteins. Gene Ontology overrepresentation analysis revealed that the proteins in the gel dominantly promote antifibrotic biological process. In vivo study using a rabbit vocal fold injury model showed that the injectable gel significantly reduced collagen density and decreased tissue contraction of the lamina propria in vocal folds with chronic scarring. Furthermore, this acellular gel only elicited minimal humoral immune response after injection. Our findings suggested that the tissue-specific, injectable extracellular matrix gel could be a promising biomaterial for treating vocal fold scarring, even after the formation of mature scar. STATEMENT OF SIGNIFICANCE: Vocal fold lamina propria scarring remains among the foremost therapeutic challenges in the management of patients with voice disorders. Surgical excision of scar may cause secondary scarring and yield inconsistent results. The present study reports an extracellular matrix-derived biomaterial that demonstrated antifibrotic effect on chronic scarring in vocal fold lamina propria. Its injectability minimizes the invasiveness of the delivery procedure and the degree of mucosal violation. In this work we also describe a new methodology which can more accurately identify proteins from the complex mixture of an acellular extracellular matrix gel by excluding interfering peptides produced during the enzymatic digestion in gel fabrication.

Regenerative potential of basic fibroblast growth factor contained in biodegradable gelatin hydrogel microspheres applied following vocal fold injury: Early effect on tissue repair in a rabbit model

Introduction

Postoperative dysphonia is mostly caused by vocal fold scarring, and careful management of vocal fold surgery has been reported to reduce the risk of scar formation. However, depending on the vocal fold injury, treatment of postoperative dysphonia can be challenging.

Objective

The goal of the current study was to develop a novel prophylactic regenerative approach for the treatment of injured vocal folds after surgery, using biodegradable gelatin hydrogel microspheres as a drug delivery system for basic fibroblast growth factor.

Methods

Videoendoscopic laryngeal surgery was performed to create vocal fold injury in 14 rabbits. Immediately following this procedure, biodegradable gelatin hydrogel microspheres with basic fibroblast growth factor were injected in the vocal fold. Two weeks after injection, larynges were excised for evaluation of vocal fold histology and mucosal movement.

Results

The presence of poor vibratory function was confirmed in the injured vocal folds. Histology and digital image analysis demonstrated that the injured vocal folds injected with gelatin hydrogel microspheres with basic fibroblast growth factor showed less scar formation, compared to the injured vocal folds injected with gelatin hydrogel microspheres only, or those without any injection.

Conclusion

A prophylactic injection of basic fibroblast growth factor -containing biodegradable gelatin hydrogel microspheres demonstrates a regenerative potential for injured vocal folds in a rabbit model.

Reversal of Vocal Fold Mucosal Fibrosis Using siRNA against the Collagen-Specific Chaperone Serpinh1

Vocal fold (VF) mucosal fibrosis results in substantial voice impairment and is recalcitrant to current treatments. To reverse this chronic disorder, anti-fibrotic therapies should target the molecular pathology of aberrant collagen accumulation in the extracellular matrix. We investigated the therapeutic potential of siRNA against Serpinh1, a collagen-specific chaperone that enables cotranslational folding and assembly of procollagens in the endoplasmic reticulum. We implemented a previously validated siRNA construct, conducted transfection experiments using in vitro and in vivo rat models, and measured knockdown efficiency, dose responses, delivery strategies, and therapeutic outcomes. Liposome-mediated delivery of Serpinh1-siRNA downregulated collagen production in naive and scar VF fibroblasts as well as naive VF mucosa; moreover, sustained Serpinh1 knockdown in fibrotic VF mucosa reversed scar-associated collagen accumulation within 4 weeks. Analysis of therapeutic effects at the transcriptome level showed evidence of cell cycle upregulation, catabolism, matrix disassembly, and morphogenesis. These findings indicate that Serpinh1-siRNA holds potential as a molecular therapy for chronic VF mucosal fibrosis.

Treatment Outcomes of Angiolytic Laser-Assisted Glottoplasty in Patients With Sulcus Vocalis

Objective:

We have been performing glottoplasty using angiolytic laser, including pulsed dye laser (PDL) or potassium titanyl phosphate (KTP) laser, for the treatment of sulcus vocalis. In this study, we retrospectively reviewed the treatment results of sulcus vocalis patients who had undergone glottoplasty using angiolytic laser and evaluated the efficacy and safety of this surgical technique.

Methods:

From January 2008 to April 2016, 79 patients with sulcus vocalis who underwent angiolytic LASER-assisted glottoplasty were enrolled in the study.

Results:

Of the 79 patients who participated in this study, 55 were male, and 24 were female. PDL was used for glottoplasty in 68 patients, and KTP was used in the remaining 11 patients. Seventy-seven patients underwent surgery for bilateral vocal cord lesions, and only 2 patients underwent surgery for unilateral vocal cord lesion. After glottoplasty using angiolytic laser, most patients showed continuous improvement of the GRBAS (grade, roughness, breathiness, asthenia, strain) score and Voice Handicap Index score until 6 months after the operation. In addition, we observed improvement of objective voice indices such as noise to harmonic ratio, jitter, shimmer, and maximal phonation time postoperatively.

Conclusions:

Based on these results, we confirmed the efficacy and safety of glottoplasty using angiolytic laser in sulcus vocalis patients. Further studies are needed to confirm appropriate laser settings such as frequency of treatments and total energy delivered to the lesion. Also, multi-institutional studies are needed to confirm the efficacy and safety of the operation.

Background Factors and Subjective Voice Symptoms in Patients with Acquired Vocal Fold Scarring and Sulcus Vocalis

OBJECTIVE

Vocal fold scarring (VFS) and sulcus vocalis (SV) often result in severe and chronic voice disorders. This study compares subjective voice complaints as rated with the Voice Handicap Index and etiological factors for patients with VFS and SV.

PATIENTS AND METHODS

Data were collected from the medical records at the Department of Otorhinolaryngology, Karolinska University Hospital, for 27 VFS patients and 27 SV patients. Descriptive background factors were compared between the groups and data were compared from the Swedish Voice Handicap Index (Sw-VHI) questionnaires.

RESULTS

Previous laryngeal surgery/trauma was significantly more common for the patients with VFS. The SV group had significantly more persistent dysphonia since childhood. It was significantly more common to have a non-Germanic language origin among the SV patients. VFS and SV rated high for the total median Sw-VHI scores. The VFS group's total Sw-VHI and the three domain scores were significantly higher compared to the SV group. The physical domain showed a significantly higher score when compared to the functional and emotional domains in the SV cohort and when compared to the emotional domain in the VFS cohort.

CONCLUSION

There are significant differences between the VFS group and SV group regarding etiological factors as well as the Sw-VHI. The degree and profile of VHI should be considered when selecting patients and evaluating the result of new treatments for this group of patients.

In vitro evaluation of a basic fibroblast growth factor-containing hydrogel toward vocal fold lamina propria scar treatment

Scarring of the vocal fold lamina propria can lead to debilitating voice disorders that can significantly impair quality of life. The reduced pliability of the scar tissue-which diminishes proper vocal fold vibratory efficiency-results in part from abnormal extracellular matrix (ECM) deposition by vocal fold fibroblasts (VFF) that have taken on a fibrotic phenotype. To address this issue, bioactive materials containing cytokines and/or growth factors may provide a platform to transition fibrotic VFF within the scarred tissue toward an anti-fibrotic phenotype, thereby improving the quality of ECM within the scar tissue. However, for such an approach to be most effective, the acute host response resulting from biomaterial insertion/injection likely also needs to be considered. The goal of the present work was to evaluate the anti-fibrotic and anti-inflammatory capacity of an injectable hydrogel containing tethered basic fibroblast growth factor (bFGF) in the dual context of scar and biomaterial-induced acute inflammation. An in vitro co-culture system was utilized containing both activated, fibrotic VFF and activated, pro-inflammatory macrophages (MΦ) within a 3D poly(ethylene glycol) diacrylate (PEGDA) hydrogel containing tethered bFGF. Following 72 h of culture, alterations in VFF and macrophage phenotype were evaluated relative to mono-culture and co-culture controls. In our co-culture system, bFGF reduced the production of fibrotic markers collagen type I, α smooth muscle actin, and biglycan by activated VFF and promoted wound-healing/anti-inflammatory marker expression in activated MΦ. Cumulatively, these data indicate that bFGF-containing hydrogels warrant further investigation for the treatment of vocal fold lamina propria scar. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1258-1267, 2018.

Role of Narrow Band Imaging in Relation to Stroboscopy and White Light Laryngoscopy in Diagnosis of Benign Nonvascular Glottic Lesions

Objective

To evaluate the role of narrow band imaging (NBI) in detecting benign nonvascular glottic lesions.

Materials and methods

Our study is a retrospective and prospective analysis of 247 patients with suspected benign glottic lesions who presented to our voice clinic over a 6-month duration. Patients were diagnosed on stroboscopy (by the first author) and divided into three groups consisting of leukoplakia, sulci, and cysts. A white light (WL) laryngoscopy and NBI examination was performed by an independent laryngologist (not an author) followed by a comparative analysis. The final gold standard for diagnosis was microlaryngoscopy with or without histopathology. Sensitivity of each modality for diagnosis of the three groups was calculated.

Results

The NBI is more sensitive for diagnosing leukoplakia. Stroboscopy is more sensitive for diagnosing sulcus.

Conclusion

Small vocal fold lesions may be missed on WL laryngoscopy. Stroboscopy helps in the diagnosis of structural glottic lesions affecting mucosal wave pattern. Many studies have shown that NBI light highlights the vasculature in superficial mucosal and subepithelial layers. This study is an analysis of the value of NBI in detecting relatively avascular glottic lesions, such as leukoplakia, sulci, and cysts.

How to cite this article

Nerurkar NK, Shedge AE, Gupta HK, Arya AA. Role of Narrow Band Imaging in Relation to Stroboscopy and White Light Laryngoscopy in Diagnosis of Benign Nonvascular Glottic Lesions. Int J Phonosurg Laryngol 2017;7(1):1-5.

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.

Practice variations in voice treatment selection following vocal fold mucosal resection

OBJECTIVES/HYPOTHESIS

To characterize initial voice treatment selection following vocal fold mucosal resection in a Medicare population.

STUDY DESIGN

Retrospective analysis of a large, nationally representative Medicare claims database.

METHODS

Patients with > 12 months of continuous Medicare coverage who underwent a leukoplakia- or cancer-related vocal fold mucosal resection (index) procedure during calendar years 2004 to 2009 were studied. The primary outcome of interest was receipt of initial voice treatment (thyroplasty, vocal fold injection, or speech therapy) following the index procedure. We evaluated the cumulative incidence of each postindex treatment type, treating the other treatment types as competing risks, and further evaluated postindex treatment utilization using the proportional hazards model for the subdistribution of a competing risk. Patient age, sex, and Medicaid eligibility were used as predictors.

RESULTS

A total of 2,041 patients underwent 2,427 index procedures during the study period. In 14% of cases, an initial voice treatment event was identified. Women were significantly less likely to receive surgical or behavioral treatment compared to men. From age 65 to 75 years, the likelihood of undergoing surgical treatment increased significantly with each 5-year age increase; after age 75 years, the likelihood of undergoing either surgical or behavioral treatment decreased significantly every 5 years. Patients with low socioeconomic status were significantly less likely to undergo speech therapy.

CONCLUSION

The majority of Medicare patients do not undergo voice treatment following vocal fold mucosal resection. Further, the treatments analyzed here appear disproportionally utilized based on patient sex, age, and socioeconomic status. Additional research is needed to determine whether these observations reflect clinically explainable differences or disparities in care.

LEVEL OF EVIDENCE

2c. Laryngoscope, 126:2505-2512, 2016.

The Efficacy of Fibroblast Growth Factor for the Treatment of Chronic Vocal Fold Scarring: From Animal Model to Clinical Application

Objectives

This study assessed the regenerative efficacy of basic fibroblast growth factor (FGF) in a rabbit model of chronic vocal fold scarring and then confirmed its utility and safety in a prospective trial of patients with this condition.

Methods

FGF was injected three times, at 1-week intervals, into a chronic vocal fold scar created in a rabbit model. After 1 month, mRNA level of procollagen I, hyaluronic acid synthetase 2 (HAS 2), and matrix metalloproteinase 2 (MMP 2) were analyzed by real-time polymerase chain reaction. The relative densities of hyaluronic acid (HA) and collagen were examined 3 months post-injection. From April 2012 to September 2014, a prospective clinical trial was conducted at a tertiary hospital in Korea. FGF was injected into the mild vocal fold scar of 17 consecutive patients with a small glottic gap. The patients underwent perceptual, stroboscopic, acoustic aerodynamic test, and Voice Handicap Index (VHI) survey prior to and 3, 6, and 12 months after FGF injection.

Results

FGF injection of the vocal fold scar decreased the density of collagen and increased mRNA level of HAS 2 and MMP 2 expression significantly compared to the control group injected with phosphate buffered solution in a rabbit model (P<0.05). In the clinical trial, significant improvements in the majority of the subjective and objective voice parameters were registered 3 months after FGF injection and were maintained at 12 months. Complications associated with the FGF injections, such as granuloma, were not observed during the follow-up period.

Conclusion

Based on the animal model and the prospective clinical trial, vocal fold injections of FGF in patients with mild chronic vocal fold scarring can significantly improve voice quality for as long as 1 year and without side effects. Our results recommend the use of FGF vocal fold injection as an alternative treatment modality for mild chronic vocal fold scarring.

High- and ultrahigh-field magnetic resonance imaging of naïve, injured and scarred vocal fold mucosae in rats

Subepithelial changes to the vocal fold mucosa, such as fibrosis, are difficult to identify using visual assessment of the tissue surface. Moreover, without suspicion of neoplasm, mucosal biopsy is not a viable clinical option, as it carries its own risk of iatrogenic injury and scar formation. Given these challenges, we assessed the ability of high- (4.7 T) and ultrahigh-field (9.4 T) magnetic resonance imaging to resolve key vocal fold subepithelial tissue structures in the rat, an important and widely used preclinical model in vocal fold biology. We conducted serial in vivo and ex vivo imaging, evaluated an array of acquisition sequences and contrast agents, and successfully resolved key anatomic features of naïve, acutely injured, and chronically scarred vocal fold mucosae on the ex vivo scans. Naïve lamina propria was hyperintense on T1-weighted imaging with gadobenate dimeglumine contrast enhancement, whereas chronic scar was characterized by reduced lamina propria T1 signal intensity and mucosal volume. Acutely injured mucosa was hypointense on T2-weighted imaging; lesion volume steadily increased, peaked at 5 days post-injury, and then decreased – consistent with the physiology of acute, followed by subacute, hemorrhage and associated changes in the magnetic state of hemoglobin and its degradation products. Intravenous administration of superparamagnetic iron oxide conferred no T2 contrast enhancement during the acute injury period. These findings confirm that magnetic resonance imaging can resolve anatomic substructures within naïve vocal fold mucosa, qualitative and quantitative features of acute injury, and the presence of chronic scar.

Summary: Magnetic resonance imaging is shown to allow the nondestructive assessment of acute injury and scar formation in vocal fold mucosa, as demonstrated ex vivo using a preclinical rat model.

Diagnostic and therapeutic pitfalls in benign vocal fold diseases

More than half of patients presenting with hoarseness show benign vocal fold changes. The clinician should be familiar with the anatomy, physiology and functional aspects of voice disorders and also the modern diagnostic and therapeutic possibilities in order to ensure an optimal and patient specific management. This review article focuses on the diagnostic and therapeutic limitations and difficulties of treatment of benign vocal fold tumors, the management and prevention of scarred vocal folds and the issue of unilateral vocal fold paresis.

Regenerative phonosurgical treatments for vocal fold scar and sulcus with basic fibroblast growth factor

OBJECTIVES/HYPOTHESIS

Vocal fold scar and sulcus are still challenges. Basic fibroblast growth factor (bFGF) has proven to be effective to resolve scar tissue in animal models. This study reports the efficacy of regenerative treatments using bFGF on vocal fold scar and sulcus in human cases.

STUDY DESIGN

Retrospective chart review.

METHODS

Fifteen cases (7 scar; 8 sulcus) were treated by either local injection of bFGF (n = 6) or regenerative surgery using bFGF (n = 9). Injection regimen was to locally apply 10 micrograms of bFGF in 0.5 mL saline into each vocal fold under topical anesthesia repeatedly (4 times with intervals of 1 week between each injection). The regenerative surgical procedure consisted of the dissection of scar tissue and the implant of gelatin sponge with bFGF. Follow-up periods ranged from 6 months to 24 months.

RESULTS

Maximum Phonation Time (MPT); Voice Handicap Index (VHI)-10; and Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS) scale were assessed in both groups. The injection group showed significant improvement on VHI-10 and GRBAS. The regenerative surgery group showed significant improvement in all parameters. Jitter and shimmer were evaluated in the surgery group, and the results indicated improvement in six and five cases of nine cases, respectively. No major adverse effects were observed in both treatment groups.

CONCLUSIONS

Regenerative treatments using bFGF has shown to be effective for improvement of vocal function in scar and sulcus.

Use of Pulsed Dye Laser in the Treatment of Sulcus Vocalis

Objective

The pulsed dye laser (PDL) has been shown to be effective in the treatment of hypertrophic scars and keloids in dermatology. On the basis of histopathologic similarities between sulcus vocalis and scar tissue and numerous reports on the treatment of laryngeal lesions, especially scar tissue, with PDL, we evaluated the efficacy of treating sulcus vocalis with PDL. We named this surgical procedure PDL glottoplasty.

Study Design

Case series with planned data collection.

Setting

A university-based, tertiary care medical center.

Subjects and Methods

This study was conducted on 25 patients diagnosed with sulcus vocalis by videostroboscopy at the Gangnam Severance Hospital Otorhinolaryngology Department between August 2006 and February 2012. Energy delivery was fixed at 0.75 Joules (J) per pulse, and each vocal fold was administered 60 to 110 pulses (average 72.5 pulses) during each procedure. Aerodynamic, stroboscopic, and acoustic voice analyses were performed pre- and postoperatively.

Results

Although assessment was necessarily subjective, our study indicated that vocal folds showed decreased stiffness and improved mucosal wave properties after treatment, resulting in improved vibration and dysphonia. In the objective assessments, most patients who underwent PDL glottoplasty showed improvement in several postoperative voice analysis indices. The differences between preoperative and some postoperative voice parameter indices were statistically significant.

Conclusion

We found PDL glottoplasty to be beneficial in the treatment of sulcus vocalis. Objective measurements of voice quality and normalization of vocal fold vibration improved after PDL treatment in most cases. Our results warrant further studies with larger numbers of participants and longer follow-up periods.

[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.

Effect of vocal fold injury location on vibratory parameters in excised canine larynges

OBJECTIVE

To investigate the effect of vocal fold injury location on vibratory amplitude and lateral phase difference.

STUDY DESIGN

Repeated measures with each excised canine larynx serving as own control.

SETTING

Basic science study conducted in university laboratory.

METHODS

Vocal fold vibration of excised canine larynges was recorded with a high-speed camera before and after inducing vocal fold injury at 1 of 5 locations: anterior, middle, posterior, medial, or superior. Medial and superior injuries were created within the middle third of the vocal fold. Five larynges were used for each of the 5 injury locations. Kymography was performed at the midpoint of the vocal folds for each video. Pre- and postinjury vibratory amplitude and lateral phase difference were compared for each location.

RESULTS

The anterior and medial injuries produced consistent decreases in vibratory amplitude. Middle and posterior injuries might slightly decrease amplitude. Superior injuries seemed to have no effect on amplitude. Anterior and medial injuries induced phase asymmetry between the right and left vocal folds. Middle injuries appeared to affect phase difference slightly, whereas posterior and superior injuries had no effect.

CONCLUSION

Injury to the anterior or medial portions of the vocal fold may be most likely to cause abnormal vocal fold vibration. Using caution in these locations during phonosurgery may favor superior postoperative vocal outcomes.

Nonlinear dynamic-based analysis of severe dysphonia in patients with vocal fold scar and sulcus vocalis

OBJECTIVE

The primary goal of this study was to evaluate a nonlinear dynamic approach to the acoustic analysis of dysphonia associated with vocal fold scar and sulcus vocalis.

STUDY DESIGN

Case-control study.

METHODS

Acoustic voice samples from scar/sulcus patients and age-/sex-matched controls were analyzed using correlation dimension (D2) and phase plots, time-domain based perturbation indices (jitter, shimmer, signal-to-noise ratio [SNR]), and an auditory-perceptual rating scheme. Signal typing was performed to identify samples with bifurcations and aperiodicity.

RESULTS

Type 2 and 3 acoustic signals were highly represented in the scar/sulcus patient group. When data were analyzed irrespective of signal type, all perceptual and acoustic indices successfully distinguished scar/sulcus patients from controls. Removal of type 2 and 3 signals eliminated the previously identified differences between experimental groups for all acoustic indices except D2. The strongest perceptual-acoustic correlation in our data set was observed for SNR and the weakest correlation was observed for D2.

CONCLUSIONS

These findings suggest that D2 is inferior to time-domain based perturbation measures for the analysis of dysphonia associated with scar/sulcus; however, time-domain based algorithms are inherently susceptible to inflation under highly aperiodic (ie, type 2 and 3) signal conditions. Auditory-perceptual analysis, unhindered by signal aperiodicity, is therefore a robust strategy for distinguishing scar/sulcus patient voices from normal voices. Future acoustic analysis research in this area should consider alternative (e.g., frequency- and quefrency-domain based) measures alongside additional nonlinear approaches.

Influence of glycosaminoglycan identity on vocal fold fibroblast behavior

Poly(ethylene glycol) (PEG) hydrogels have recently begun to be studied for the treatment of scarred vocal fold lamina propria due, in part, to their tunable mechanical properties, resistance to fibroblast-mediated contraction, and ability to be polymerized in situ. However, pure PEG gels lack intrinsic biochemical signals to guide cell behavior and generally fail to mimic the frequency-dependent viscoelastic response critical to normal superficial lamina propria function. Recent results suggest that incorporation of viscoelastic bioactive substances, such as glycosaminoglycans (GAGs), into PEG networks may allow these gels to more closely approach the mechanical responses of normal vocal fold lamina propria while also stimulating desired vocal fold fibroblast behaviors. Although a number of vocal fold studies have examined the influence of hyaluronan (HA) on implant mechanics and vocal fold fibroblast responses, the effects of other GAG types have been relatively unexplored. This is significant, since recent studies have suggested that chondroitin sulfate C (CSC) and heparan sulfate (HS) are substantially altered in scarred lamina propria. The present study was therefore designed to evaluate the effects of CSC and HS incorporation on the mechanical response of PEG gels and vocal fold fibroblast behavior relative to HA. As with PEG-HA, the viscoelasticity of PEG-CSC and PEG-HS gels more closely approached that of the normal vocal fold lamina propria than pure PEG hydrogels. In addition, collagen I deposition and fibronectin production were significantly higher in CSC than in HA gels, and levels of the myofibroblast marker smooth muscle α-actin (SM α-actin) were greater in CSC and HS gels than in HA gels. Since collagen I, fibronectin, and SM α-actin are generally elevated in scarred lamina propria these results suggest that CSC and HS may be undesirable for vocal fold implants relative to HA. Investigation of various signaling intermediates indicated that alterations in NFκB-p50, NFκB-p65, or pERK1/2 levels may underlie the observed differences among the PEG-GAG gels.

Implantation of atelocollagen sheet for vocal fold scar

PURPOSE OF REVIEW

This article reviews recent advances in scaffold-based interventions for the treatment of vocal fold scarring, with a particular emphasis on atelocollagen sheet implantation in the vocal fold lamina propria.

RECENT FINDINGS

Scaffold-based therapies have demonstrated therapeutic promise in both preclinical and early clinical studies. Recent research has begun to shed light on the interactions between scaffold material properties, encapsulated and infiltrating cells, stimulatory molecules such as growth factors, and external regulatory variables such as stress, strain, and vibration. The atelocollagen sheet, a cross-linked collagen material with abundant micropores, has an established clinical track record as a scaffold for dermal and epidermal repair and exhibited potential therapeutic benefit in a recent study of patients with vocal fold scarring and sulcus vocalis.

SUMMARY

Scaffolding is one of the useful tools in tissue engineering and atelocollagen sheet implantation has been shown to be effective in vocal fold regeneration. However, many of the scaffold materials under investigation still await clinical translation and those that have been investigated in human patients (such as the atelocollagen sheet) require additional research in appropriately powered placebo-controlled studies.

Cause of vocal fold scar

PURPOSE OF REVIEW

The prolonged debilitation, loss of income, and decrement in quality of life caused by vocal fold scar is exacerbated by our inability to successfully treat this difficult problem. As technology focuses on developing innovative treatments, we need to fully appreciate and understand the mechanisms giving rise to glottal scar, on both a macroscopic and microscopic level. This review examines recent literature pertaining to the gross and molecular mechanisms which give rise to vocal fold scar.

RECENT FINDINGS

Mechanisms of vocal fold scar production have been examined in both macroscopic and microscopic detail. Trauma and injury involving any aspect of the lamina propria, particularly the deeper layers, may result in epithelial tethering and scar formation. At the molecular level, early inflammatory cytokines activate and recruit fibroblasts which then drive the fibrotic cascade. Transforming growth factor-β enhances fibrosis and is balanced by tissue matrix metalloproteinases and hepatocyte growth factor activity. Molecular signaling offers novel opportunities to intervene in scar formation.

SUMMARY

New work investigating the cause of vocal fold scar identifies complex molecular processes leading to fibrosis in the lamina propria. Improved mechanistic understanding offers insight into prevention strategies and possible targets for antifibrotic therapies that may help prevent or treat this debilitating condition.

Hyaluronic acid for the treatment of vocal fold scars

PURPOSE OF REVIEW

In vocal fold scars the lamina propria layer is lost or deficient. Lamina propria replacement therapy remains a clinical challenge because this layer has a highly specialized three-dimensional organization of extracellular matrix molecules and unique viscoelastic properties. Use of a polymer such as hyaluronic acid appears most promising for replacement therapy because it has the optimal viscoelasticity and also plays a role in the maturation and maintenance of vocal fold lamina propria.

RECENT FINDINGS

A variety of cross-linked hyaluronic acid formulations and growth factor therapies targeted to increase hyaluronic acid production have been used in the treatment of both acute and established vocal fold scars. Therapeutic strategies have focused on prevention of scar at the time of initial injury, and rejuvenation of lamina propria layer in established scars. Both strategies show improved histologic, viscoelastic, acoustic, and aerodynamic measures.

SUMMARY

Cross-linked hyaluronic acid formulations appear useful in the treatment of vocal fold scarring. Their use at the time of acute injury especially appears to lessen the degree of long-term scar formation and appears promising. While animal studies have demonstrated the safety profile of many hyaluronic acid formulations, further improvement in these materials and well designed and controlled human trials are needed to further establish the safety and efficacy of these materials and therapeutic approaches.

Sulcus mucosal slicing technique

PURPOSE OF REVIEW

To present the accurate surgical indication for the slicing mucosal technique, the case selection, surgical aspects, rehabilitation concerns, and the characteristics of immediate and long-term outcomes.

RECENT FINDINGS

The literature is still scarce; few cases are submitted to the slicing mucosa technique due to its specific indication; an alternative procedure was designed for cases where mucosal movement is strongly reduced, the inner section of the vocal ligament or submucosal scar tissue, which can eventually be associated with fat inclusion. Some selected cases may require thyroplasty type III to optimize functional results.

SUMMARY

Slicing technique is an aggressive powerful resource for the surgical treatment of severe cases of sulcus striae major, in which mucosal wave is absent and glottic chink is moderate to severe; voice is intensely deviated immediately postoperation; vocal rehabilitation is mandatory and an intensive regimen is usually required for the first 2 months; final results can mostly be achieved up to 6 months.

Formant analysis in dysphonic patients and automatic Arabic digit speech recognition

Background and objective

There has been a growing interest in objective assessment of speech in dysphonic patients for the classification of the type and severity of voice pathologies using automatic speech recognition (ASR). The aim of this work was to study the accuracy of the conventional ASR system (with Mel frequency cepstral coefficients (MFCCs) based front end and hidden Markov model (HMM) based back end) in recognizing the speech characteristics of people with pathological voice.

Materials and methods

The speech samples of 62 dysphonic patients with six different types of voice disorders and 50 normal subjects were analyzed. The Arabic spoken digits were taken as an input. The distribution of the first four formants of the vowel /a/ was extracted to examine deviation of the formants from normal.

Results

There was 100% recognition accuracy obtained for Arabic digits spoken by normal speakers. However, there was a significant loss of accuracy in the classifications while spoken by voice disordered subjects. Moreover, no significant improvement in ASR performance was achieved after assessing a subset of the individuals with disordered voices who underwent treatment.

Conclusion

The results of this study revealed that the current ASR technique is not a reliable tool in recognizing the speech of dysphonic patients.

Prospective multi-arm evaluation of surgical treatments for vocal fold scar and pathologic sulcus vocalis

OBJECTIVES/HYPOTHESIS

The purpose of this study was to compare the clinical effectiveness of type I thyroplasty, injection laryngoplasty, and graft implantation for the treatment of vocal fold scar and pathologic sulcus vocalis.

STUDY DESIGN

Prospective, multi-arm, quasi-experimental research design.

METHODS

Twenty-eight patients with newly diagnosed vocal fold scar and/or pathologic sulcus vocalis were assigned to one of three treatment modalities: type I thyroplasty (n = 9), injection laryngoplasty (n = 9), and graft implantation (n = 10). Psychosocial, auditory-perceptual, acoustic, aerodynamic, and videostroboscopic data were collected pretreatment and at 1, 6, 12, and 18 months posttreatment.

RESULTS

Type I thyroplasty and graft implantation both resulted in reduced voice handicap with no concomitant improvement in auditory-perceptual, acoustic, aerodynamic, or vocal fold physiologic performance. Injection laryngoplasty resulted in no improvement on any vocal function index. Patients who underwent graft implantation exhibited the slowest improvement trajectory across the 18-month follow-up period.

CONCLUSIONS

A persistent challenge in this area is that no single treatment modality is successful for the majority of patients, and there is no evidence-based decision algorithm for matching a given treatment to a given patient. Progress therefore requires the identification and categorization of predictive clinical features that can drive evidence-based treatment assignment.

Reactive response of fibrocytes to vocal fold mucosal injury in rat

Fibrocytes hold a prominent role in inflammatory and tissue repair processes in various organ systems. In this study, we identified and quantified a reactive fibrocyte population in the vocal fold mucosa postinjury using immunohistochemistry and stereological analysis. These cells, which expressed CD11b on their surface and prolyl-4-hydroxylase β (P4H-β) intracellularly, were largely restricted to the lamina propria, and were morphologically and immunochemically distinguishable from newly recruited epithelial cells. We validated our immunohistochemistry findings using flow cytometry, and additionally characterized a reactive fibrocyte population in circulating peripheral blood using a novel detection panel (CD16(-) CD11b(+) P4H-β(+) ). Fibrocyte recruitment peaked at 3 days postinjury in peripheral blood, and 5 days postinjury in the vocal fold mucosa. These findings suggest that circulating fibrocytes are recruited to sites of tissue injury in the vocal fold mucosa, and may play an important role in vocal fold tissue repair. The results of this study are consistent with published data from other organ systems and strongly suggest the importance of fibrocytes as therapeutic targets. Our newly reported antigen panel facilitating the direct characterization of fibrocytes via flow cytometry is a useful tool with the potential to facilitate improved study of this cell population.

Implantation of gelatin sponge combined with injection of autologous fat for sulcus vocalis

OBJECTIVE

To evaluate the effectiveness of gelatin sponge implantation combined with the injection of autologous fat for the treatment of sulcus vocalis.

STUDY DESIGN

Prospective cohort study.

SETTING

The research was conducted at the Eye, Ear, Nose, and Throat Hospital of Fudan University.

SUBJECTS AND METHODS

Twelve cases of sulcus vocalis were treated. The fibrotic tissue was dissected and a gelatin sponge was implanted into the affected vocal fold followed by injection of autologous fat. Videostroboscopy, maximum phonation time (MPT), and acoustic data were completed before and after surgery.

RESULTS

One month after surgery, the affected vocal fold displayed mild swelling, without evidence of a sulcus and with satisfactory glottal closure. Three months later, vocal vibration and mucosal wave were improved with the vocal fold displaying a more normal shape. Although voices did not achieve complete normalcy, the patients exhibited a better voice, with improved fundamental frequency, jitter, shimmer, normalized noise energy, and a significantly longer maximum phonation time (P < 0.05).

CONCLUSION

Implantation of gelatin sponge combined with injection of autologous fat can be used to treat sulcus vocalis. The absorbable gelatin sponge can be used to fill the superficial lamina propria temporarily to prevent the readhesion of the detached mucosa at the bottom of the sulcus to the underlying tissue, while the injected fat adequately diminishes the insufficient glottal closure.

Liver-derived extracellular matrix as a biologic scaffold for acute vocal fold repair in a canine model

OBJECTIVES/HYPOTHESIS

The objective of the study was to evaluate a naturally derived liver extracellular matrix (L-ECM) scaffold for repair of an acute injury to the vocal fold lamina propria in a canine model.

METHODS

The vocal fold lamina propria was removed bilaterally in four dogs. One vocal fold in each dog was repaired with a porcine L-ECM scaffold, which was chosen because it contains hepatocyte growth factor, an antifibrotic growth factor that aids the healing of vocal folds. The other vocal fold was left untreated. At 3 months after surgery, morphologic and histologic analysis was performed to assess the vocal fold shape, collagen density, collagen composition, elastic fiber content, and glycosaminoglycan content.

RESULTS

The L-ECM-treated vocal fold showed increased collagen density in the superficial aspect of the vocal fold (P < .05). The L-ECM-treated vocal fold also showed an increased collagen III/I ratio as compared to the nontreated group (P < .05). However, the elastic fiber content was found to be increased in both groups, and the glycosaminoglycan content was decreased in both groups as compared to the normal vocal fold (P < .05) with no differences detected between groups.

CONCLUSIONS

The L-ECM scaffold did not restore the biochemical composition or histologic appearance of the injured vocal fold as compared to normal. However, the increased ratio of collagen III/I and elastic fiber content suggests that L-ECM leads to formation of connective tissue that may be more pliable as compared to no treatment. Additional investigation, including functional assessment, is warranted.