Vocal fold scars: a common classification proposal by the American Laryngological Association and European Laryngological Society

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.

Duration of Clinical Response After In-Office Steroid Injection for Vocal Fold Scar

OBJECTIVE

To assess the duration of clinical response after in-office vocal fold steroid injection (VFSI) for vocal fold (VF) scar.

METHODS

Demographic and clinical data for in-office VFSI occurring from 2017 to 2020 were collected. Two Speech-Language Pathologists (SLPs) used perceptual evaluation of voice and functional scales to evaluate blinded voice and laryngovideostroboscopy (LVS) samples collected pre- and post-injection across multiple timepoints.

RESULTS

Blinded SLP ratings were used for 30 individual VFs undergoing initial injection in 18 patients. Persistent improvement in voice past 6 months was seen in 57% of patients after VFSI. Multiple measures of voice and amplitude, percent vibrating tissue, and closed phase predominance significantly improved at various follow-up timepoints on average.

CONCLUSION

Accounting for patient heterogeneity and disease progression, in-office VFSI for VF scar is associated with sustained improvement in a subset of patients. Approximately half of patients can expect to experience a lasting improvement in voice. Future studies of larger scale are required to identify patient factors associated with long-term benefit.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:2333-2339, 2023.

Voice Outcomes Following Serial Office-Based Steroid Injections and Voice Therapy for Vocal Fold Scar

OBJECTIVE

Previous studies indicate that certain voice outcomes can improve following a single office-based steroid injection with voice therapy for vocal fold scar. We evaluated voice outcomes after a series of three timed office-based steroid injections with voice therapy.

STUDY DESIGN

Retrospective case series with chart review.

SETTING

Academic medical center.

METHODS

We evaluated pre-and postprocedural patient-reported, perceptual, acoustic, aerodynamic, and videostroboscopic parameters. We evaluated 23 patients who underwent three office-based dexamethasone injections into the superficial lamina propria one month apart. All patients pursued voice therapy.

RESULTS

Voice Handicap Index (n = 19; P= .030) decreased after injection series. Total GRBAS score (grade, roughness, breathiness, asthenia, strain) decreased (n = 23; P = 0.001). Dysphonia severity index score improved (n = 20; P = 0.041). Phonation threshold pressure did not decrease significantly (n = 22; P = 0.536). Videostroboscopic parameters of vocal fold edge (P = 0.023), right mucosal wave (P = 0.023) improved or normalized after injection series. Glottic closure (P = 0.134) did not improve.

CONCLUSIONS

Series of three office-based steroid injections combined with voice therapy for vocal fold scar does not appear to provide further benefit than one injection. Despite lack of improvements of PTP and other parameters, injection series is likewise unlikely to worsen dysphonia. A partially negative study provides value in investigation of less invasive treatment alternatives for a disorder that is challenging to treat. Future studies exploring effects of voice therapy alone without other intervention and consideration of sham injection versus steroid injection are warranted.

Establishment and characterization of immortalized human vocal fold fibroblast cell lines

PURPOSE

Vocal fold scarring is abnormal scar tissue in the lamina propria layer of the vocal fold. To facilitate investigation of vocal fold scarring, we established and characterized immortalized human vocal fold fibroblast (iHVFF) cell lines.

METHODS

Human vocal fold fibroblasts were immortalized by introducing Simian virus 40 large T antigen (SV40TAg) by transfection. Successfully transfected fibroblasts were sorted using flow cytometry. Immunofluorescence cytochemistry and western blot were applied to analyze the expression of fibronectin, vimentin, alpha-smooth muscle actin (α-SMA) and fibroblast activation protein (FAP). Cell proliferation rate was measured by CCK-8 assay. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to analyze the mRNA expression level.

RESULTS

The iHVFFs continued to proliferate for more than 30 generations and appeared spindle-shaped. The expression of Vimentin and α-SMA were detected in both iHVFFs and primary fibroblasts, and enhanced expression of FAP was observed in iHVFFs. Furthermore, iHVFFs exhibited an increased proliferative capability compared with the primary fibroblasts. RT-qPCR results suggested that collagen type III alpha 1 chain (COL3A1), interleukin-6, cyclooxygenase 2 (COX2), hyaluronan synthase 2 (HAS2), hepatocyte growth factor (HGF) in the iHVFFs significantly increased, whereas transforming growth factor-β1 (TGF-β1), elastin and matrix metallopeptidase-1 (MMP-1) expression significantly downregulated. No differences in mRNA expression of α-SMA, fibronectin and collagen type I alpha 2 chain (COL1A2) were noted between iHVFFs and primary fibroblasts.

CONCLUSION

iHVFFs can be used as a novel tool cell for future researches on the mechanisms of pathogenesis and treatment of vocal fold scarring.

Platelet-Rich Plasma for Vocal Fold Scar: A Preliminary Report of Concept

INTRODUCTION

Vocal fold atrophy and scar can lead to loss of normal superficial lamina propria, negatively affecting the vibratory function of the vocal fold. These changes can lead to dysphonia, vocal fatigue, decreased volume, and altered pitch. Treatment options for these conditions are limited. Platelet-rich plasma (PRP) consists of platelets, growth factors, and cytokines derived from the patient's own blood and is believed to activate tissue regeneration. The purpose of this study was to review the technical aspects of collecting PRP and injecting it into the vocal fold injection - based on our initial experience with this procedure.

CASE

A patient with vocal fold scar was identified and enrolled in an ongoing prospective clinical trial study of a series of 4 monthly subepithelial vocal fold PRP injections, which was temporarily halted due to the COVID-19 pandemic. Patient underwent a single injection of autologous PRP into the left vocal fold. There were no adverse events during the study period. Subjective improvement in voice was noted at 1 month after injection with subsequent return to baseline over the next 4 months. Videostroboscopy performed on postinjection day 1 and day 7 and demonstrated no concerning exam changes. Compared to the preinjection baseline, the patient-reported voice-handicap index-10 (VHI-10) and voice catastrophization index were similar at 4 months following injection (20 to 20 and 4 to 3, respectively). Independent perceptual analysis of voice showed improvement at 4 months postinjection, compared to baseline consensus auditory-perceptual evaluation of voice 60 to 44.

CONCLUSIONS

This preliminary report was part of a prospective trial investigating the use of PRP to treat vocal fold atrophy and scar. This work highlights the technical considerations for injecting PRP into the vocal fold. Planned prospective enrollment in this study will help to validate the safety and efficacy of PRP injections.

Using Diffusion Tensor Imaging to Explore the Changes in the Microstructure of Canine Vocal Fold Scar Tissue

OBJECTIVE

To apply diffusion tensor imaging (DTI) in measurement of the diffusion characteristics of water molecules in vocal fold scar tissue, combined with the analysis of textural characteristics of collagen fibers in the cover layer of the vocal folds to explore the feasibility of DTI in the qualitative and quantitative diagnosis of vocal fold scars and the evaluation of microstructural changes of vocal fold scar tissue.

METHODS

A unilateral injury was created using micro-cup forceps in the left vocal fold of six beagles. The contralateral normal vocal fold was used as a self-control. Five months postinjury, the larynges were excised and placed into a magnetic resonance imaging (MRI) system (9.4T BioSpec MRI, Bruker, German) for scanning and extraction of the diffusion parameters, fractional anisotropy (FA) and tensor trace in the anterior, middle, and posterior portions of the vocal fold cover layer. These parameters were then analyzed for statistical significance between the scarred vocal fold and the normal vocal fold. After MRI scanning, the tissue of the vocal folds was divided into anterior, middle, and posterior parts for sectioning and staining with hematoxylin and eosin, and samples were subsequently digitally scanned for texture analysis. The irregularity parameters, energy, contrast, correlation, and homogeneity, of collagen fibers of the vocal folds and the mean gray value of collagen fibers were calculated by the gray-level co-occurrence matrix (GLCM) texture analysis method. The differences in the mean value of the two sides of the vocal fold were compared. In addition, Pearson correlation analysis was performed between DTI parameters and irregularity parameters.

RESULTS

The FA of the left vocal fold cover layer was significantly lower compared to the self-control group (P = 0.0366), and the tensor trace value on the left vocal fold cover layer was significantly higher compared to the self-control group (P = 0.0353). The FA was significantly higher in the anterior part of the right vocal fold cover layer compared to the middle and posterior parts of the same side (P = 0.0352), and the tensor trace was significantly lower in the anterior part of the right vocal fold cover layer compared to the middle and posterior parts of the same side (P = 0.0298). There were no significant differences in FA and tensor trace between the middle and posterior parts of the vocal fold cover layer. The mean gray value of the left vocal folds cover layer was significantly smaller than the right vocal fold cover layer (P = 0.0219), the energy of the left vocal fold cover layer was significantly smaller than that of the right vocal fold cover layer (P < 0.0001), the contrast of the left vocal folds cover layer was significantly larger than that of the right vocal fold cover layer (P = 0.0002), the correlation of the left vocal folds cover layer was significantly smaller than the right vocal fold cover layer (P = 0.0002), and the homogeneity of the left vocal folds cover layer was significantly smaller than the right vocal fold cover layer (P = 0.0003). Pearson correlation analysis yielded values of r = 0.926, P = 0.000 between the FA and mean gray value; r = -0.918, P = 0.000 between FA and energy; r = -0.924, P = 0.000 between the FA and homogeneity, r = -0.949, P = 0.000 between tensor trace and mean gray value; r = 0.893, P = 0.000 between the tensor trace and energy; and r = 0.929, P = 0.000 between the tensor trace and homogeneity.

CONCLUSION

FA and tensor trace can be used as effective parameters to reflect microstructural changes in vocal fold scars. DTI is an objective and quantitative method of analyzing vocal fold scarring, and it noninvasively evaluates the microstructure of vocal fold collagen fibers.

Scarless Healing of Injured Vocal Folds Using an Injectable Hyaluronic Acid-Waterborne Polyurethane Hybrid Hydrogel to Tune Inflammation and Collagen Deposition

Vocal fold (VF) scarring results from injury to the unique layered structure and is one of the main reasons for long-lasting dysphonia. A minimally invasive procedure with injectable hydrogels is a promising method for therapy. However, current surgical techniques or standard injectable fillers do not yield satisfactory outcomes. In this work, an injectable hybrid hydrogel consisting of oxide hyaluronic acid and hydrazide-modified waterborne polyurethane emulsion was injected precisely into the injury site and cross-linked in situ by a dynamic hydrazone bond. The prepared hydrogel displays excellent injectability and self-healing ability, showing favorable biocompatibility and biodegradability to facilitate endogenous newborn cell migration and growth for tissue regeneration. With the aim of evaluating the antifibrosis and regeneration capacity of the hybrid hydrogel in the VF scarring model, the morphology and vibration characteristics of VFs, inflammatory response, and healing status were collected. The hybrid hydrogel can decrease the inflammation and increase the ratio of collagen III/collagen I to heal damaged scar-free tissue. Fascinatingly, the mucosal wave oscillations of healing VF by injecting the hybrid hydrogel were vibrated like the normal VF, achieving functional restoration. This work highlights the utility of hybrid hydrogels consisting of synthetic biodegradable waterborne polyurethane emulsions and natural hyaluronic acid as promising biomaterials for scarless healing of damaged VFs.

Intracordal injection therapy for vocal fold scarring: Steroid versus basic fibroblast growth factor

Objectives

Vocal fold scarring is caused by replacement of vocal fold mucosa with fibrous tissue due to repeated inflammation or trauma. It can lead to severe dysphonia. It is currently treated conservatively and with phonosurgery and intracordal injections. Intracordal injection of steroid or basic fibroblast growth factor (bFGF) has been recently found to be useful for treating vocal fold scarring that does not respond to voice therapy.

Methods

This retrospective study involved the administration of steroid injection and bFGF injection bilaterally under local anesthesia in 16 patients each. Laboratory measurements of voice parameters were performed before and 3–6 months after injection.

Results

In the steroid injection group, the Voice Handicap Index (VHI) score significantly improved from 57.1 to 40.5, total Grade, Roughness, Breathiness, Asthenia, Strain (tGRBAS) score significantly improved from 4.2 to 2.6, and mean speech fundamental frequency (SFF) increased from 192.5 to 211.4 dB, but there was no improvement in maximum phonation time (MPT) and mean airflow rate (MFR). In the bFGF injection group, significant improvements in the VHI score (from 53.3 to 35.7), MPT (from 16.9 to 21.8 s) and MFR (from 314.6 to 210.5 ml/s) were seen; however, the tGRBAS score did not improve. In addition, the SFF significantly decreased from 178.1 to 160.5 Hz.

Conclusion

These results suggest that both steroid and bFGF injections are effective for treating vocal fold scarring, with steroids improving voice quality and bFGF improving glottic closure, thereby contributing to improvements in VHI scores.

Level of Evidence

4.

Paracrine Effects of Adipose-Derived Cellular Therapies in an in Vitro Fibrogenesis Model of Human Vocal Fold Scarring

OBJECTIVES/HYPOTHESIS

Vocal folds (VF) scarring leads to severe dysphonia which negatively impacts daily life of patients. Current therapeutic options are limited due in large part to the high complexity of the micro-structure of the VF. Innovative therapies derived from adipose tissue such as stromal vascular fraction (SVF) or adipose derived stromal/ stem cells (ASC) are currently being evaluated in this indication and paracrine anti-fibrotic effects are considered as predominant mechanisms.

METHODS

The paracrine anti-fibrotic effects of SVF and ASC from healthy donors were tested in an innovative in vitro fibrogenesis model employing human VF fiboblasts (hVFF) and the principles of macromolecular crowding (MMC). Biosynthesis of collogen and alpha-smooth-muscle actin (αSMA) expression in hVFF were quantified after five days of indirect coculture with ASC or SVF using silver stain, western blot and RT-qPCR analysis.

RESULTS

Fibrogenesis was promoted by addition of transforming growth factor beta 1 (TGFβ1) combined with MMC characterized by an enhanced deposition of fibrillar collagens and the acquisition of a myofibroblast phenotype (overexpression of αSMA). Adipose-derived therapies led to a reduction in the αSMA expression and the collagen content was lower in hVFF co-cultivated with SVF.

CONCLUSIONS

ASC and SVF promoted significant prevention of fibrosis in an in vitro fibrogenesis model through paracrine mechanisms, supporting further development of adipose-derived cellular therapies in VF scarring.

Vocal fold sulci - what are the current options for and outcomes of treatment?

PURPOSE OF REVIEW

Sulcus vocalis is a benign condition of the vocal folds that, according to its severity, can affect the quality of the voice of those who have it. Voice symptoms can range from mild to severe, affecting the quality of life of patients with this condition. Although different surgical and no surgical options have been described, no gold standard treatment has been described.

RECENT FINDINGS

New evidence supports congenital, inflammatory, and acquired theories for sulcus vocalis. Also, recent literature demonstrated the role of the epithelium in the pathogenesis, which makes the absence of superficial lamina propria no longer the only accepted hypothesis. Technological developments improved the in-office diagnostics capabilities for this condition, but vocal fold palpation remains the gold standard. Different benign laryngeal conditions are associated with sulcus vocalis and knowing when to treat those is very important. Different treatment options are available for sulcus vocalis, however, results are diverse and no strong recommendations for one over the other can be made.

SUMMARY

Progress continues to be made in our understanding of sulcus vocalis from diagnosis to treatment. Novel and promising therapeutic strategies have been recently developed for this condition; however, more data and investigations are needed to improve their accuracy and reproducibility.

Current approaches to management of vocal fold scar

PURPOSE OF REVIEW

Vocal fold (VF) fibrosis remains an insoluble problem in most cases, with a severe impact on vocal quality and effort. This review examines current investigations and research strands that explore the understanding of VF wound healing and applied treatments for the management of VF scar.

RECENT FINDINGS

Recent work focused on VF fibrosis has examined wound healing in the glottis, fibrosis-modifying medication, and tissue engineering approaches that span cytokine and growth factor therapy, scaffold and cell delivery platforms, seeded scaffolds, conditioned media and stem cell therapy. Many show promise and may deliver improvements in the wound bed favouring less fibrogenic healing patterns, ultimately with the goal of preserving or restoring VF vibration. Further collaborative research is required that examines combined approaches, long term outcomes, better three-dimensional modelling of cell-cell interactions and delivery modalities for molecular therapies.

SUMMARY

VF fibrosis research continues to expand and explore a variety of mechanistic pathways in order to understand VF healing and identify novel and complementary targets for manipulation. Many different approaches show promise and may also offer synergistic benefits. Research continues to strive for healing that more closely resembles true VF architecture and function.

Comparison of therapeutic effects of steroid injection by benign vocal fold lesion type

BACKGROUND

Benign vocal fold lesions (BVFLs) can cause voice changes, including reduced loudness and pitch range. In recent times, with progression in endoscopic technology, office-based vocal fold steroid injection (VFSI) has been used as an alternative therapy for BVFLs.

AIMS/OBJECTIVES

In this study, we analyzed the efficacy and safety of VFSI to investigate the mechanism underlying its therapeutic effects and determine the conditions in which VFSI will be most effective.

MATERIALS AND METHODS

In this retrospective cohort study, we included 40 condition-matched patients (8 patients per lesion) with chorditis, vocal nodules, vocal polyps, Reinke's edema (RE), or vocal scars who received similar regimens of steroid injection using a commercial preparation of triamcinolone acetonide. Their phonological outcomes were evaluated 2 or 3 months after the injection.

RESULTS

Significant improvements were observed in Voice Handicap Index scores, results of laboratory voice evaluation, and voice quality measured using the Grade, Roughness, Breathiness, Asthenia, Strain scale in all participants. In subgroup analysis, VFSI was highly effective against chorditis and vocal nodules, but less effective against RE and vocal scars.

CONCLUSIONS

Single-dose VFSI is valuable as an alternative to voice rehabilitation and laryngo-microsurgery, but higher concentrations or repeated injections are required for intractable lesions.

Comparison of the effects of platelet-rich plasma and dexamethasone ınjection on scar formation after vocal fold ınjury in rabbits

OBJECTIVES

In this study, a histopathological comparison was aimed between platelet-rich plasma (PRP) injection and dexamethasone injection in the prevention of scar formation after vocal fold injury.

MATERIALS AND METHODS

Electrocautery was applied to damage the right and left vocal folds of a total of 12 New Zealand rabbits. PRP obtained from the rabbit's own blood was injected into the right vocal fold, and dexamethasone was injected into the left vocal fold. After 8 weeks, the experimental animals were euthanized, and the levels of inflammatory cell infiltration, vascularization, collagen, elastin, and hyaluronic acid (HA) were compared in histopathological evaluation.

RESULTS

In statistical comparison of histopathological data obtained; in terms of plasma cell infiltration, vascularization, and edema parameters, statistically significant results were obtained in favor of the PRP group. Although the difference between collagen, elastin and HA, which are critical in vocal fold scar healing, was more positive in favor of PRP, no significant result was revealed in the statistical evaluation.

CONCLUSIONS

PRP injection in rabbits with vocal fold damage reveals similar characteristics with dexamethasone injection in preventing scar formation. PRP injection has favorable effects on vascularization, prevention of edema, and number of plasma cells.

Asiatic Acid Improves Extracellular Matrix Remodeling in Vocal Fold Scarring Via SMAD7 Activation

OBJECTIVES/HYPOTHESIS

Vocal fold (VF) fibroblasts are the central target for developing new strategies for the treatment of VF scarring and fibrosis. Asiatic acid (AA) is a triterpenoid derivate with antifibrotic properties. However, the effect of AA in VF scarring is poorly understood. The objective of this study was to investigate the potential application of AA as a therapeutic treatment in VF scarring.

STUDY DESIGN

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METHODS

The functional expression of SMAD7 was knocked down with recombinant adenoviruses and adeno-associated viruses carrying shRNAs in the in vitro and in vivo models, which were constructed to investigate AA's antifibrotic function. The expression of collagens and SMADs in cultured human and rabbit cell lines and animal models was evaluated with quantitative reverse transcription polymerase chain reaction and immunohistochemistry labeling, respectively. Cell migration capacity and contraction in VF fibroblast cell lines were also evaluated.

RESULTS

AA downregulated the downstream fibrotic activation in a dose-dependent manner. Meanwhile, AA attenuated VF scarring/fibrosis by reducing collagen deposition. Furthermore, the antifibrotic effects of AA were associated with the upregulation of SMAD7. In contrast, knockdown of SMAD7 inhibited the effect of AA on transforming growth factor-beta-1 (TGF-β1) stimulation, which suggests a central role for SMAD7 in AA-induced antifibrotic activities during VF fibrosis.

CONCLUSION

We concluded that AA, which is a novel therapeutic candidate for preventing VF scarring/fibrosis, might exert its antifibrotic effect via the TGF-β1/SMAD signaling pathway.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2021.

Use of 532 nm Potassium Titanyl Phosphate Laser on Vocal Fold Scars Under Topical Anesthesia: A Pilot Study

OBJECTIVE

This pilot study aims to evaluate the efficacy of 532 nm potassium titanyl phosphate (KTP) laser under topical anesthesia in patients with vocal fold scars.

METHODS

A series of 18 patients with vocal fold scars of varying degrees were treated. The KTP laser was used under local anesthesia in the outpatient clinic. It was set to deliver 6 W of power using a continuous output mode. Close-to-contact mode was used for laser irradiation, and contact mode was used for ablation and excision of the lesions. Some of the patients received laser scar ablation on both vocal folds; the scarred vocal fold on one side and the hypertrophic vocal fold on the other. Parameters include glottic closure, amplitude, and mucosal wave pattern were measured using laryngeal stroboscopic examination. Aerodynamic and voice evaluations were carried out using maximum phonation time (MPT), jitter, shimmer, Voice Handicap Index questionnaire (VHI-30), and GRBAS scale.

RESULTS

In total, 21 surgeries were performed on 18 patients. Glottic closure, amplitude, and mucosal wave pattern showed improvement 2 months postoperatively (P < .05). There was significant improvement in the postoperative scores for VHI-30, VHI-emotional sub-scale, VHI-physical sub-scale, and GRBAS (P < .05). There was no significant difference in the MPT and VHI-functional sub-scale before and after the operation (P > .05). Re-adhesion of the anterior commissure was observed in 2 patients with Type III scars.

CONCLUSION

The 532 nm KTP laser is an effective tool for the treatment of vocal fold scars. Further research is required to determine if serial laser applications could improve outcomes for this challenging condition.

LEVEL OF EVIDENCE

Level IV.

Feasibility of First Injection of Autologous Adipose Tissue-Derived Stromal Vascular Fraction in Human Scarred Vocal Folds: A Nonrandomized Controlled Trial

Importance

Patients with scarred vocal folds, whether congenitally or after phonosurgery, often exhibit dysphonia that negatively affects daily life and is difficult to treat. The autologous adipose tissue-derived stromal vascular fraction (ADSVF) is a readily accessible source of cells with angiogenic, anti-inflammatory, immunomodulatory, and regenerative properties.

Objective

To evaluate the feasibility and tolerability of local injections of autologous ADSVF in patients with scarred vocal folds.

Design, Setting, and Participants

CELLCORDES (Innovative Treatment for Scarred Vocal Cords by Local Injection of Autologous Stromal Vascular Fraction) is a prospective, open-label, single-arm, single-center, nonrandomized controlled trial with a 12-month follow-up and patient enrollment from April 1, 2016, to June 30, 2017. Eight patients with severe dysphonia attributable to vocal fold scarring associated with a congenital malformation or resulting from microsurgical sequelae (voice handicap index score >60 of 120) completed the study. Data analysis was performed from September 1, 2018, to January 1, 2019.

Interventions

Injection of ADSVF into 1 or 2 vocal folds.

Main Outcomes and Measures

The primary outcomes were feasibility and the number and severity of adverse events associated with ADSVF-based therapy. The secondary outcomes were changes in vocal assessment, videolaryngostroboscopy, self-evaluation of dysphonia, and quality of life at 1, 6, and 12 months after cell therapy.

Results

Seven women and 1 man (mean [SD] age, 44.6 [10.4] years) were enrolled in this study. Adverse events associated with liposuction and ADSVF injection occurred; most of them resolved spontaneously. One patient received minor treatment to drain local bruising, and another experienced a minor contour defect at the liposuction site. At 12 months, the voice handicap index score was improved in all patients, with a mean (SD) improvement from baseline of 40.1 (21.5) points. Seven patients (88%) were considered to be responders, defined as improvement by 18 points or more in the voice handicap index score (the minimum clinically important difference).

Conclusions and Relevance

The findings suggest that autologous ADSVF injection in scarred vocal folds is feasible and tolerable. The findings require confirmation in a randomized clinical trial with a larger population.

Trial Registration

ClinicalTrials.gov Identifier: NCT02622464.

Commentary about mesenchymal stem cells and scarred vocal folds

A commentary to “Hertegård, S., Nagubothu, S.R., Malmström, E. et al. Treatment of vocal fold scarring with autologous bone marrow-derived human mesenchymal stromal cells - first phase I/II human clinical study. Stem Cell Res Ther 11, 128 (2020)” concerning the surgical intervention including a scar resection, the use of the Voice Handicap Index, the surgical and regulatory points of view regarding the inclusion of patients with laryngeal carcinomas history, and the side effects of bone marrow harvesting.