Injection Laryngoplasty Using Autologous Fat Enriched with Adipose-Derived Regenerative Stem Cells: A Safe Therapeutic Option for the Functional Reconstruction of the Glottal Gap after Unilateral Vocal Fold Paralysis

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.

Tissue Engineering as a Promising Treatment for Glottic Insufficiency: A Review on Biomolecules and Cell-Laden Hydrogel

Glottic insufficiency is widespread in the elderly population and occurs as a result of secondary damage or systemic disease. Tissue engineering is a viable treatment for glottic insufficiency since it aims to restore damaged nerve tissue and revitalize aging muscle. After injection into the biological system, injectable biomaterial delivers cost- and time-effectiveness while acting as a protective shield for cells and biomolecules. This article focuses on injectable biomaterials that transport cells and biomolecules in regenerated tissue, particularly adipose, muscle, and nerve tissue. We propose Wharton's Jelly mesenchymal stem cells (WJMSCs), induced pluripotent stem cells (IP-SCs), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), insulin growth factor-1 (IGF-1) and extracellular vesicle (EV) as potential cells and macromolecules to be included into biomaterials, with some particular testing to support them as a promising translational medicine for vocal fold regeneration.

Otorhinolaryngological Advancements in Phoniatrics

The production of voice is a powerful tool not only for communication, but also for artistic performances [...]

Autologous Fat Plus Platelet-Rich Plasma versus Autologous Fat Alone on Sulcus Vocalis

Sulcus vocalis is a frequent cause of glottic insufficiency that leads to incomplete vocal fold closure during phonation. Type II sulcus vocalis is defined as a partial defect of the lamina propria (LP). Treatment with fillers, such as fat or hyaluronic acid (HA), in the vocal folds is widely used, but the duration of effect is variable. Platelet-rich plasma (PRP) can enhance the survival of autologous fat in fat grafting, and also is used to treat sulcus vocalis. This study aimed to compare the effectiveness of autologous fat graft versus fat graft plus PRP to treat type II sulcus vocalis. Thirty-four patients with a voice handicap index (VHI) ≥ 11 were randomized to two groups, which received LP injections of fat graft (n = 17) or fat graft plus PRP (n = 17). At 1 month and 6 months after injection, the VHI decreased significantly in both groups. The fat plus PRP group had better Jitter, Shimmer, and noise to harmonic ratio (NHR) in 1 month and 6 months after surgery. The fat plus PRP group resulted in lower VHI scores one month after surgery, and stroboscopy revealed sustained smaller gaps after six months. These results indicate that a combination of fat graft plus PRP is safe and effective for treating sulcus vocalis type II and associated vocal atrophy.

Infiltration of the Hoffa's fat pad in patients with osteoarthritis of the knee-Results after one year of follow-up

Objectives

Cell therapy using multipotential stromal cells (MSCs) is being used in a variety of clinical settings to induce tissue regeneration. Promising results have also been achieved in the therapy of osteoarthritis. MSCs have been demonstrated to be safe (Borakati et al., 2018). They can be used in a one step procedure as minimally manipulated mesenchymal stem cells or after in vitro expansion. The in vitro step allows for the selection of a more homogeneous cell population, meeting the standard criteria for MSC identification (Lv et al., 2014). In vitro expansion of MSCs is cost intensive, time consuming and furthermore associated with gradual accumulation of senescent cells (Wagner et al., 2008), telomere erosion (Baxter et al., 2004), and changing phenotypes (Jones et al., 2010; Halfon et al., 2011). These disadvantages could be surpassed by the use of “minimally manipulated mesenchymal stem cells” from bone marrow or adipose tissue (Di Matteo et al., 2019) such as the adipogenic stromal-vascular fraction (SVF).

The study investigates whether infiltration of the Hoffa fat pad with autologous SVF is an effective and safe treatment option for patients with gonarthrosis. Furthermore, the number and vitality of the injected cells as well as the clinical efficacy will be evaluated.

Materials and methods

We conduct a prospective study. Patients with osteoarthritis of the knee receive infiltration of SVF into the Hoffa fat pad. The number and vitality of the cells are measured with a cell counter. The clinical outcome is checked using VAS, KOOS and SF12 questionnaires with a follow-up period of 1 year.

Results

A total of 33 patients and 36 knees were included in this Study. An average of 45 million cells were injected with a standard deviation of 2,5 million Cells. After 6 months a significant improvement of the VAS and the respective subscales of the KOOS could be observed compared to the baseline. After one year of follow-up, a significant improvement in all KOOS subscales compared to baseline was still observed. A significant correlation between reduced knee pain on the VAS and the number of injected cells could be observed as well. Thus, patients injected with a higher number of cells seem to have a better outcome. The average viability of the cells was 64,4% with a standard deviation of 15,9%. A correlation between higher cell viability and better outcome on the QOL subscale of the KOOS was observed. There were no major complications or side effects.

Discussion

These initial results indicate that treatment with SVF is a safe therapeutic option that has the potential to relieve joint pain and significantly improved function. The cell number and vitality of the injected cells appear to be important factors influencing the success of the therapy.

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.

Respiratory and voice outcomes of office-based injection laryngoplasty in patients with unilateral vocal fold paralysis

Background

Injection laryngoplasty is a surgical procedure used in management of glottal insufficiency. The objective of this study was to assess respiratory and voice outcomes of office-based injection laryngoplasty in patients with unilateral vocal fold paralysis (UVFP). Ten patients underwent office-based injection via transcutaneous approach using Radiesse or hyaluronic acid. Auditory perceptual assessment (APA), voice handicap index (VHI), size of the glottic gap, acoustic parameters (jitter, shimmer, and harmonic to noise ratio), maximum phonation time (MPT), stroboscopic evaluation, pulmonary function tests (PFTs), and videofluoroscopic evaluation of swallowing were done pre-injection, 1 week and 3 months post-injection.

Results

Subjective and objective voice outcomes, in addition to laryngostroboscopic parameters improved after injection. Non-significant difference was found between pre- and post-injection results of the PFTs.

Conclusions

Office-based injection laryngoplasty is a safe and effective method for treating UVFP. Patients with glottic gap (< 1–3 mm) are perfect candidates for such procedure. Injection laryngoplasty improves patients’ voice quality and does not impair respiration.

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.

MRI Study of Jellyfish Collagen, Hyaluronic Acid, and Cadaveric Dermis for Injection Laryngoplasty

OBJECTIVES/HYPOTHESIS

Test a new jellyfish collagen biomaterial aimed to increase duration of injection medialization laryngoplasty (IL) against two products in clinical practice.

STUDY DESIGN

Animal model.

METHODS

Left recurrent laryngeal nerve sectioning and IL were performed in New Zealand White rabbits (N = 6/group). Group 1 received micronized cross-linked jellyfish collagen (MX-JC) and adipose derived stem cells (ADSCs), Group 2, MX-JC alone, Group 3, cross-linked hyaluronic acid (X-HA), and Group 4, micronized acellular dermis (MACD). Animals were sacrificed at 4 and 12 weeks. Major outcomes were MRI tissue volumes and histopathology.

RESULTS

After 100 μL IL MRI volumes (means ± STD) at 4 and 12 weeks were: Group 1: 27.2 ± 15.6 and 13.1 ± 5.2 μL, Group 2: 60.8 ± 18 and 27.8 ± 2.47 μL, Group 3: 27.4 ± 12 and 10.6 ± 8 μL, and Group 4: 37.5 ± 11 and 9.85 ± 1 μL. Group 2 volumes were largest and Group 3 were smallest in all comparisons (P < .05). Histologically, low grade inflammatory responses were observed in Group 1, mild histiocytic infiltration in Group 2, widespread muscle fiber loss in Group 3, and plasmocytic infiltration in Group 4.

CONCLUSIONS

MX-JC showed the least resorption at 4 and 12 weeks among all groups. T cell inflammatory responses were observed with MX-JC but were reduced by 12 weeks while B cell immune responses, indicative of antibody priming, were predominantly noted with MACD. MX-JC + ADSC showed low grade immunity while the XHA showed greater myocyte loss compared to the other groups.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E2452-E2460, 2021.

Objective evaluation of biomaterial effects after injection laryngoplasty - Introduction of artificial intelligence-based ultrasonic image analysis

OBJECTIVE

Hyaluronic acid (HA) can be degraded over time. However, persistence of the effects after injection laryngoplasty (IL) for unilateral vocal fold paralysis (UVFP), longer than expected from HA longevity, has been observed. The purpose of the study was to develop a methodology with clinical utility for objective evaluation of the temporal change in HA volume after IL using artificial intelligence (AI)-based ultrasonic assessment.

DESIGN, SETTING AND PARTICIPANTS

Imaging phantoms simulating injected HA were built in different volumes for designing the algorithm for machine learning. Subsequently, five adult patients who had undergone IL with HA for UVFP were recruited for clinical evaluation.

MAIN OUTCOME MEASURES

Estimated volumes were evaluated for injected HA by the automatic algorithm as well as voice outcomes at 2 weeks, and 2 and 6 months after IL.

RESULTS

On imaging phantoms, contours on each frame were described well by the algorithm and the volume could be estimated accordingly. The error rates were 0%-9.2%. Moreover, the resultant contours of the HA area were captured in detail for all participants. The estimated volume decreased to an average of 65.76% remaining at 2 months and to a minimal amount at 6 months while glottal closure remained improved.

CONCLUSION

The volume change of the injected HA over time for an individual was estimated non-invasively by AI-based ultrasonic image analysis. The prolonged effect after treatment, longer than HA longevity, was demonstrated objectively for the first time. The information is beneficial to achieve optimal cost-effectiveness of IL and improve the life quality of the patients.

Cryopreserved human adipose-derived stromal vascular fraction maintains fracture healing potential via angiogenesis and osteogenesis in an immunodeficient rat model

Background

Novel therapeutic strategies for the healing of nonunion, which has serious effects on the quality of life of patients, are needed. We evaluated the therapeutic effect of local transplantation of human stromal vascular fraction (SVF) cells on fracture healing in a rat non-healing fracture model and compared the effects between freshly isolated (F) and cryopreserved (C)-SVFs.

Methods

Non-healing fracture model was induced in the femur of female immunodeficient rats (F344/N Jcl rnu/rnu) with cauterizing periosteum. Immediately after the creation of non-healing fracture, rats received local transplantation of F and C-SVFs suspended in phosphate-buffered saline (PBS) or the same volume of PBS without cells using the same scaffold as a control group. During 8 weeks post-surgery, radiologic, histological, immunohistochemical, and biomechanical analyses were performed to evaluate fracture healing. The comparison of radiological results was performed with a chi-square test, and the multiple comparisons of immunohistochemical, histological, and biomechanical results among groups were made using a one-way analysis of variance. A probability value of 0.05 was considered to denote statistical significance.

Results

At week 8, in 60% of animals receiving F-SVF cells and in 50% of animals receiving C-SVF cells, the fracture radiologically healed with bone union whereas nonunion was observed in the control group. The healing potential was also confirmed by histological and biomechanical assessments. One of the mechanisms underlying healing involving intrinsic angiogenesis/osteogenesis was enhanced in F- and C-SVF groups compared with that in the control group. Human cell-derived vasculogenesis/osteogenesis, which was also confirmed in an in vitro differentiation assay, was also enhanced in the F- and C-SVF groups compared with that in the control groups and could be another mechanism for healing.

Conclusions

SVF cells can enhance bone healing and cryopreserved cells have almost equal potential as fresh cells. SVF cells can be used for improving nonunion bone fracture healing as an alternative to other mesenchymal stem cells and the effect of SVF cells can be maintained under cryopreservation.

Regenerative medicine approaches for the management of respiratory tract fistulas

Respiratory tract fistulas (or fistulae) are abnormal communications between the respiratory system and the digestive tract or the adjacent organs. The origin can be congenital or, more frequently, iatrogenic and the clinical presentation is heterogeneous. Respiratory tract fistulas can lead to severely reduced health-related quality of life and short survival. Therapy mainly relies on endoscopic surgical interventions but patients often require prolonged hospitalization and may develop complications. Therefore, more conservative regenerative medicine approaches, mainly based on lipotransfer, have also been investigated. Adipose tissue can be delivered either as unprocessed tissue, or after enzymatic treatment to derive the cellular stromal vascular fraction. In the current narrative review, we provide an overview of the main tissue/cell-based clinical studies for the management of various types of respiratory tract fistulas or injuries. Clinical experience is limited, as most of the studies were performed on a small number of patients. Albeit a conclusive proof of efficacy cannot be drawn, the reviewed studies suggest that grafting of adipose tissue-derived material may represent a minimally invasive and conservative treatment option, alternative to more aggressive surgical procedures. Knowledge on safety and tolerability acquired in prior studies can lead to the design of future, larger trials that may exploit innovative procedures for tissue processing to further improve the clinical outcome.

The influence of adipose-derived stromal vascular fraction cells on the treatment of knee osteoarthritis

Background

Adipose-derived stromal vascular fraction (SVF) cells are a mixed cell population that includes cells with multilineage potential, similar to bone marrow-derived mesenchymal stem cells. Our purpose is to investigate the influence of SVF cells in patients with knee osteoarthritis (OA) and the short-term treatment effects.

Methods

Fifty-seven patients were enrolled and treated with intra-articular injection of 2.5 × 10⁷ SVF cells into the knee joint between September 2017 and March 2018. All patients were followed up for 12 months or longer. Mean age at treatment and follow-up period were 69.4 ± 6.9 years and 13.7 ± 2.0 months, respectively. The mean preoperative hip-knee-ankle angle was 6.7 ± 3.6°. SVF cells were prepared using the Celution®800/CRS system from the patients’ abdominal or breech subcutaneous fat. The mean SVF cell viability was 90.6 ± 2.7%. Clinical evaluations were performed for range of motion, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analog scale (VAS) for pain, and the Knee injury and Osteoarthritis Score (KOOS). Imaging evaluations, which included the hip-knee-ankle angle assessed via radiography, and T2 mapping value using a 1.5-T magnetic resonance imaging unit were also assessed. Both clinical and imaging evaluations were performed preoperatively, 1, 3, 6, and 12 months postoperatively, and compared among all timepoints (p < 0.05).

Results

Knee extension angle at 6 and 12 months postoperatively was significantly better than the preoperative angle. Total WOMAC, VAS, and KOOS scores at 1, 3, 6 and 12 months postoperatively were significantly better than preoperative scores. There was no significant difference in hip-knee-ankle angle among the five time periods. T2 mapping values of lateral femur and tibia were significantly higher 12 months postoperatively than preoperatively.

Conclusions

The short-term clinical effects of intra-articular SVF cell injection on knee OA were excellent. Intra-articular SVF cell injection is a novel and innovative approach for treating patients with knee OA.

Porcine Vocal Fold Lamina Propria-Derived Biomaterials Modulate TGF-β1-Mediated Fibroblast Activation in Vitro

The vocal fold lamina propria (VFLP), one of the outermost layers of the vocal fold (VF), is composed of tissue-specific extracellular matrix (ECM) proteins and is highly susceptible to injury. Various biomaterials have been clinically tested to treat voice disorders (e.g., hydrogels, fat, and hyaluronic acid), but satisfactory recovery of the VF functionality remains elusive. Fibrosis or scar formation in the VF is a major challenge, and the development and refinement of novel therapeutics that promote the healing and normal function of the VF are needed. Injectable hydrogels derived from native tissues have been previously reported with major advantages over synthetic hydrogels, including constructive tissue remodeling and reduced scar tissue formation. This study aims to characterize the composition of a decellularized porcine VFLP-ECM scaffold and the cytocompatibility and potential antifibrotic properties of a hydrogel derived from VFLP-ECM. In addition, we isolated potential matrix-bound vesicles (MBVs) and macromolecules from the VFLP-ECM that also downregulated smooth muscle actin ACTA2 under transforming growth factor-beta 1 (TGF-β1) stimulation. The results provide evidence of the unique protein composition of the VFLP-ECM and the potential link between the components of the VFLP-ECM and the inhibition of TGF-β1 signaling observed in vitro when transformed into injectable forms.