Transcervical fat injection laryngoplasty for unilateral vocal fold paralysis: an easy way to do the job

Early Changes in Porcine Larynges Following Injection of Motor-Endplate Expressing Muscle Cells for the Treatment of Unilateral Vocal Fold Paralysis

OBJECTIVES

No curative injectable therapy exists for unilateral vocal fold paralysis. Herein, we explore the early implications of muscle-derived motor-endplate expressing cells (MEEs) for injectable vocal fold medialization after recurrent laryngeal nerve (RLN) injury.

METHODS

Yucatan minipigs underwent right RLN transection (without repair) and muscle biopsies. Autologous muscle progenitor cells were isolated, cultured, differentiated, and induced to form MEEs. Three weeks after the injury, MEEs or saline were injected into the paralyzed right vocal fold. Outcomes including evoked laryngeal electromyography (LEMG), laryngeal adductor pressure, and acoustic vocalization data were analyzed up to 7 weeks post-injury. Harvested porcine larynges were examined for volume, gene expression, and histology.

RESULTS

MEE injections were tolerated well, with all pigs demonstrating continued weight gain. Blinded analysis of videolaryngoscopy post-injection revealed infraglottic fullness, and no inflammatory changes. Four weeks after injection, LEMG revealed on average higher right distal RLN activity retention in MEE pigs. MEE-injected pigs on average had vocalization durations, frequencies, and intensities higher than saline pigs. Post-mortem, the MEE-injected larynges revealed statistically greater volume on quantitative 3D ultrasound, and statistically increased expression of neurotrophic factors (BDNF, NGF, NTF3, NTF4, NTN1) on quantitative PCR.

CONCLUSIONS

Minimally invasive MEE injection appears to establish an early molecular and microenvironmental framework to encourage innate RLN regeneration. Longer follow-up is needed to determine if early findings will translate into functional contraction.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:272-282, 2024.

Vocal Fold Fat injection for Glottic Insufficiency: Systematic Review

Vocal fold fat injection is a technique for treating glottic insufficiency (GI) resulting from various conditions. The use of fat as a graft has several advantages over other grafts. Similar pliability, and vibratory characteristics as a normal vocal fold, not causing foreign body reactions, having the potential to contain stem cells, and often can be done in the office. Long-term results, however, are unpredictable. The objective of this study is to carry out a systematic review of published articles using the technique of fat injection in the vocal folds.

STUDY DESIGN

Systematic review.

REVIEW METHODS

A literature search was conducted utilizing the combination of the following keywords "vocal folds fat injection," "laryngoplasty," and "autologous fat injection vocal folds." The criteria inclusion of the study for the systematic review were based on PICOTS (population, intervention, comparison outcome, timing, and setting) and Preferred Reporting Items for Systematic Reviews and Meta-analyses statements. Outcomes reviewed included technique, study duration, perceptual and acoustic analysis, and quality of life preoperation and 1-year postoperation.

RESULTS

A systematic review on PubMed, Cochrane, and Embase databases included 13 studies analyzing the data of 472 patients, that had fat injection laryngoplasty for treatment of GI. The causes of GI varied substantially across studies. Considerable heterogeneity across studies was found, including technique for harvest, processing the fat, site of injection, and acoustic analysis. In the studies that measured maximum phonation time (MPT) there was a significant improvement in a follow-up of at least 1 year after the injection. The patient's perception of vocal quality, measured by the Voice Handicap Index, also showed significant improvement in several studies after fat injection laryngoplasty.

CONCLUSION

Fat injection laryngoplasty seems to be safe and effective for GI for at least 12 months. Multiple studies show favorable outcomes, but the lack of control groups, the heterogeneity in inclusion criteria, nonstandardized techniques, and objective voice evaluations limit this evaluation.

Lipoinjection for Unilateral Vocal Fold Paralysis Treatment: A Systematic Review and Meta-Analysis

INTRODUCTION

Lipoinjection is one of the available treatments for unilateral vocal fold paralysis.

OBJECTIVE

To evaluate lipoinjection predictability, and analyze the differences in safety and efficacy of the different techniques.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS AND RESULTS

A systematic review on Medline, Cochrane, and Scopus databases included 49 articles analyzing the data of 1,166 patients, concerning technical details and voice parameters changes. Lipoinjection used a mean volume of 1.3 mL, 95% confidence interval (CI) (0.92, 1.69)-average overcorrection of 30%. Meta-analysis of pre- and postoperative voice parameters' means showed a significant improvement at 6 months of mean phonation time (preoperative: 5.12, 95% CI [4.48, 5.76]-6 months: 10.46, 95% CI [9.18, 11.75]), Jitter (preoperative: 2.71, 95% CI [2.08, 3.33])-6 months: 1.37, 95% CI [1.05, 1.70]), Shimmer (preoperative: 4.55, 95% CI [3.04, 6.07]-6 months: 2.57, 95% CI [1.69, 3.45]), grade (preoperative: 2.15, 95% CI [1.73, 2.57]-6 months: 0.12, 95% CI [0.97, 1.43]), breathiness (preoperative: 2.012, 95% CI [1.48, 2.55]-6 months: 0.99, 95% CI [0.58, 1.40]), and asthenia (preoperative: 1.90, 95% CI [1.33, 2.47]-6 months: 0.75, 95% CI [0.17, 1.33]) of GRBAS (Grade, Roughness, Breathiness, Asthenia and Strain), and Voice Handicap Index-30 (preoperative: 72.06, 95% CI [54.35, 89.76]-6 months: 26.24, 95% CI [19.58, 32.90]). Subgroup analysis by harvesting technique concluded in no statistically significant difference between them. Few complications were reported. Reintervention was only required for 86 patients.

CONCLUSION

Lipoinjection seems a safe therapeutic option for unilateral vocal fold paralysis, with available data showing an efficacy lasting 6 months to 1 year. Laryngoscope, 2021.

Autologous Fat Injection Laryngoplasty for Unilateral Vocal Fold Paralysis

BACKGROUND

Unilateral vocal palsy (UVFP) affects the voice and swallowing function and could be treated by various materials to achieve improved mucosal wave and better closure during phonation. Injection laryngoplasty is considered an exemplary method for these patients and could be injected as early as possible. We conducted a systematic review and meta-analysis for the subjective and objective outcomes of autologous fat injection laryngoplasty (AFIL) and assessed the effects for patients with UVFP.

METHODS

We searched studies from PubMed and EBSCO databases with PRISMA appraisal to search for articles about the effects of AFIL on UVFP. The published articles were reviewed according to our inclusion and exclusion criteria. The short- and long-term outcomes of perceptual, acoustic analysis, and quality of life were also analyzed by meta-analysis.

RESULTS

Eleven articles were reviewed, and seven studies were selected for meta-analysis. AFIL improves the perceptual outcome and some voice parameters in short-term and long-term results, i.e., jitter, shimmer, and maximal phonation time (MPT). It also significantly improved the voice handicap index (VHI) in the long term, suggesting an increase in quality of life.

CONCLUSIONS

AFIL is considered a reliable treatment method for UVFP and could even last for over 12 months.

Autologous Lipoaugmentation Long-Term Clinical Outcomes: A Systematic Review

OBJECTIVES/HYPOTHESIS

Vocal fold (VF) lipoaugmentation can be employed to treat glottal insufficiency although variable data exist on its length of effectiveness. We aimed to review published long-term outcomes following lipoaugmentation across the literature and compile outcome data.

STUDY DESIGN

Systematic review.

METHODS

A systematic search in September 2020 of PubMed, MEDLINE, Cochrane Library, and Web of Science used the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines to identify 128 relevant articles related to VF lipoaugmentation effectiveness duration. Primary search terms included the following: vocal cord, fat, lipo, and atrophy. Forty-eight full-text articles were reviewed and 31 were included in the final analysis. Primary endpoints included the following: duration of effectiveness per patient-reported outcome measures, objective findings, and additional procedures performed. In addition, fat harvest location and processing techniques were recorded.

FINDINGS

Thirty-one studies totaling 764 patients were included in the review. Indications for augmentation were VF paralysis (N = 690) and atrophy (N = 74). Fat was harvested from the abdominal region in 21 studies (529 patients), the thigh/abdomen in 5 studies (91 patients), and buccal/submental region in 2 studies (33 patients). Processing techniques and injectable volume varied. Across included studies, only 11 of 764 patients (1.4%) reported no improvement in voice and/or swallowing. Within the first year, 71 of 608 patients (11.7%) reported a regression toward baseline. Beyond 1 year and up to 8 years, 27 of 214 patients (12.6%) reported regression from initial improvement. Thirty-three patients underwent additional procedures.

CONCLUSION

Although improvements in voice and swallowing after lipoaugmentation taper over time, most patients experienced long-term benefit. Laryngoscope, 2021.

Five-year results of vocal fold augmentation using autologous fat or calcium hydroxylapatite

PURPOSE

To evaluate 5-year voice outcomes of vocal fold augmentation (VFA) using autologous fat (AF) injection via direct microlaryngoscopy versus office-based calcium hydroxylapatite (CaHA) injection.

METHODS

Retrospective study of patients who underwent VFA between 2012 and 2015, with a 5-year follow-up. Patients with a glottic gap of ≤ 3 mm caused by unilateral vocal fold paralysis or vocal fold atrophy were included in the study. VFA was performed using AF injection via direct microlaryngoscopy in 17 patients, and using office-based CaHA injection in 19 patients. Subjective satisfaction with voice, voice handicap index (VHI), and maximal phonation time (MPT) were analyzed pre-injection, and at 12 and 60 months post-VFA.

RESULTS

Altogether 36 patients underwent VFA between 2012 and 2015, of whom 5 were excluded within 1 year post-VFA, and 2 were excluded between 1 and 5 years post-VFA. Of the remaining 29 patients, 3 (10.3%) underwent re-intervention at between 1 and 3 years post-VFA. Thus, the 5-year follow-up included 26 patients (72.2%; 11 males and 15 females). At 5 years after surgery, 73.1% of the patients were satisfied with their voice, with no significant between-group difference (P = 0.307). The mean improvement of VHI was 28.8 ± 17.82 in the autologous fat group versus 33 ± 26.24 in the CaHA group (P = 0.458). MPT improvement was also similar between the two groups: 6.2 ± 4.26 for the autologous fat group versus 6.3 ± 4.34 for the CaHA group (P = 0.667).

CONCLUSIONS

Both AF injection via direct microlaryngoscopy and office-based CaHA injection yielded good and comparable 5-year results.

Augmentation of Scarred Vocal Folds With Centrifuged and Emulsified Autologous Fat Grafts

Objective

To review the results of a series of patients with glottic insufficiency caused by scarred vocal folds who underwent injection laryngoplasty with centrifuged and emulsified autologous fat.

Study Design

Prospective cohort.

Setting

Single center, tertiary institution.

Subjects and Methods

Examination of the medical records of 21 patients operated on through injection laryngoplasty with fat grafts for the treatment of dysphonia was performed. All patients were operated on between January of 2015 and September of 2019. The voice variables measured were the GRABS (Grade, Roughness, Breathiness, Asthenia, Strain) scale, the Voice Handicap Index–10 (VHI-10), maximum phonation time, jitter, shimmer, and harmonic/noise ratio before surgery and 8 months later.

Results

Twenty-six injection laryngoplasties were performed in 21 patients during the reviewed period. Seventeen were men, and 4 were women. Mean age was 57.2 (range, 18-80) years. Mean (SD) follow-up time was 20.7 (9.3) months. Etiology of dysphonia was scarring after tumor resection in 17 patients and sulcus vocalis in 4. Five patients received an additional injection laryngoplasty. Statistically significant improvements were observed in all the parameters evaluated ( P < .05).

Conclusions

Injection laryngoplasty with fat grafts processed through centrifugation and emulsification is an effective technique for the treatment of dysphonia caused by glottic insufficiency related to scarred vocal folds, with minimal complication rates.

The surgical treatment of unilateral vocal cord paralysis (UVCP): qualitative review analysis and meta-analysis study

PURPOSE

The objectives of this meta-analysis were to summarize the key surgical procedures for UVCP and to evaluate which of these is associated with better results in terms of vocal improvement.

METHODS

A systematic review of the literature was conducted in search of articles focused on the comparison of voice outcome between different techniques for the UVCP treatment. Then, a quantitative analysis was carried out for papers published from 2013 onwards, reporting only adult patients with unilateral paralysis for each study, and each surgical technique was evaluated for its capability of achieving good functional outcomes in terms of GRBAS-I scale and maximum phonation time in seconds (MPT).

RESULTS

The search identified 1853 publications. A total of 159 articles were stratified and included according to our selection criteria. 21 out of 159 articles were selected for quantitative synthesis. For trans-oral techniques: the mean GRBAS-I scale were 2.33 before injection and 0.41 after injection. The mean MPT before injection were 4.78 and 12.50 after injection. For open techniques the mean GRBAS-I scale were 2.43 before surgery and 0.68 after surgery. For open technique, the mean MPT were 3.50 before surgery and 12.40 after surgery.

CONCLUSIONS

The two types of techniques lead to an improvement in terms of vocal outcomes emphasizing that from the examined literature an indication emerges to perform an early injection because this could reduce the possible need for a more invasive intervention of permanent medialization in the future.