Growth factors expression in hyaluronic acid fat graft myringoplasty

Hyaluronic Acid Gel as Middle Ear and External Auditory Canal Packing Material in Tympanoplasty

OBJECTIVE

This study aims to evaluate the effect of hyaluronic acid gel (HAG) on tympanic membrane (TM) graft success rate and audiometric outcomes in patients with large TM perforations during tympanoplasty.

STUDY DESIGN

A single-blinded randomized controlled trial.

SETTING

Tertiary hospital.

METHODS

In the study, we performed tympanoplasty via postauricular approach on 488 ears and compared 2 groups: the control group (n = 247) with absorbable gelatin sponge packing and the HAG group (n = 241) with HAG packing in both the middle ear and medial 2/3 of the external auditory canal. We compared the graft success rates and postoperative audiometric outcomes between the 2 groups.

RESULTS

In a study of 488 ears (HAG group = 241, control group = 247), the HAG group had a higher graft success rate of 96.7% (233/241 ears) compared to the control group's 91.5% (226/247 ears; P = .015). No significant difference was observed between HAG and control in postoperative ABG closure within 20 dB (HAG: 66.8% or 161 ears; control: 59.1% or 146 ears; P = .078). There were no significant differences in improvements, compared to their preoperative condition, in mean bone conduction (HAG: -0.1 ± 6.5; control: 1.3 ± 7.6), air conduction (HAG: 8.7 ± 12.1; control: 9.7 ± 13.1), air-bone gap (HAG: 8.8 ± 10.6; control: 8.4 ± 12.0), and speech reception threshold (HAG: 9.4 ± 11.8; control: 9.2 ± 13.5) between the control and HAG groups (two one-sided T test, P < .001).

CONCLUSION

In tympanoplasty, HAG packing in the middle ear and external auditory canal yields higher graft success rates than absorbable gelatin sponge, while audiometric outcomes are similar for both the HAG and absorbable gelatin sponge packing cohorts.

Fatter Is Better: Boosting the Vascularization of Adipose Tissue Grafts

Adipose tissue resorption after fat grafting is a major drawback in plastic and reconstructive surgery, which is primarily caused by the insufficient blood perfusion of the grafts in the initial phase after transplantation. To overcome this problem, several promising strategies to boost the vascularization and, thus, increase survival rates of fat grafts have been developed in preclinical studies in recent years. These include the angiogenic stimulation of the grafts by growth factors and botulinum neurotoxin A, biologically active gels, and cellular enrichment, as well as the physical and pharmacological stimulation of the transplantation site. To transfer these approaches into future clinical practice, it will be necessary to establish standardized procedures for their safe application in humans. If this succeeds, the surgical outcomes of fat grafting may be markedly improved, resulting in a significant reduction of the physical and psychological stress for the patients.

Use of hyaluronic acid matrix in dorsal augmentation rhinoplasty

Augmentation rhinoplasty sometimes is required for patients with saddle nose deformity caused by failed rhinoplasty or facial trauma; finding appropriate grafting material remains a significant problem for this procedure. We investigated hyaluronic acid matrix as an allograft for dorsal augmentation rhinoplasty in a rabbit model. We performed an osteotomy on the nasal bones of eight rabbits. Four animals were sham operated as the control group and four were administered a mixture of saline-gelled hyaluronic acid matrix and sliced cartilage. Ultrasonography and three-dimensional reconstruction tomography were performed at the end of the experimental period. After sacrifice of the animals, nasal tissues were examined for histopathology, and both collagen scores and number of capillaries were compared between the two groups. Increased collagen and capillaries were apparent in the hyaluronic acid matrix group compared to controls. The median collagen score was significantly greater for the hyaluronic acid matrix group than for the control group. Although the number of capillaries for the hyaluronic acid matrix group was greater than for the control group, the difference was not statistically significant. Three weeks is sufficient for adhesion of ends of fractures in clinical practice; however, we found no ossification at this time in either group. A hyaluronic acid matrix may be a useful alternative supplement for dorsal augmentation rhinoplasty. Development of collagen was commensurate with membranous ossification; however, assessment of complete ossification requires a longer experimental period.

3D printing technology and applied materials in eardrum regeneration

Tympanic membrane perforation is a common condition in clinical otolaryngology. Although some eardrum patients can self-heal, a long period of non-healing perforation leads to persistent otitis media, conductive deafness, and poor quality of life. Tympanic membrane repair with autologous materials requires a second incision, and the sampling site may get infected. It is challenging to repair tympanic membranes while maintaining high functionality, safety, affordability, and aesthetics. 3D bioprinting can be used to fabricate tissue patches with materials, factors, and cells in a design manner. This paper reviews 3D printing technology that is being used widely in recent years to construct eardrum stents and the utilized applied materials for tympanic membrane repair. The paper begins with an introduction of the physiological structure of the tympanic membrane, briefly reviews the current clinical method thereafter, highlights the recent 3D printing-related strategies in tympanic membrane repair, describes the materials and cells that might play an important role in 3D printing, and finally provides a perspective of this field.

Effects of hyaluronic acid on the bone healing after lateral osteotomy: an experimental animal model

OBJECTIVE

Postoperative comfort of the patients undergoing rhinoplasty might be poor because of edema and ecchymosis caused by lateral osteotomy. In this animal experiment, we aimed at performing a quantitative assessment of effects of hyaluronic acid usage on healing process of lateral osteotomy.

METHODS

Fourteen New Zealand rabbits with a weight of 2000-2500 kg and an age of 8-12 weeks were included. Under anesthesia, nasal dorsums were exposed with midline incision and lateral osteotomies on both sides were performed using a 2 mm chisel. A hyaluronic acid-based mesh (Hyalonect^®) (1 × 1 cm) was embedded on the left osteotomy areas of all rabbits. Right osteotomy areas were left blank as control group. Collagen density and capillary development were quantitatively compared.

RESULTS

Convergence of fracture lines was observed in 6 (60%) of 10 samples from Hyalonect^® group, while was observed in 4 (40%) of 10 samples from control group. Although a higher rate of convergence was seen in the Hyalonect^® group (60% vs 40%), the difference was not statistically significant (p = 0.5). Median collagen score was 2 (1-3) in the Hyalonect^® group and 1 (1-2) in the control group. Median capillary count value was 4 (1-23) in the Hyalonect^® group and 3 (1-17) in the control group. Both collagen score and capillary count values were significantly greater in the in the Hyalonect^® group compared with the control group (p = 0.023 and p = 0.019, respectively).

CONCLUSION

The effects of hyaluronic acid-based meshes on the bone healing process of the lateral osteotomy area might be investigated furthermore, on more comprehensive studies, as a material facilitating collagen organization and capillary development.

Fat Graft Enrichment Strategies: A Systematic Review

BACKGROUND

Autologous fat grafting is a dynamic modality used in plastic surgery as an adjunct to improve functional and aesthetic form. However, current practices in fat grafting for soft-tissue augmentation are plagued by tremendous variability in long-term graft retention, resulting in suboptimal outcomes and repetitive procedures. This systematic review identifies and critically appraises the evidence for various enrichment strategies that can be used to augment and improve the viability of fat grafts.

METHODS

A comprehensive literature search of the Medline and PubMed databases was conducted for animal and human studies published through October of 2017 with multiple search terms related to adipose graft enrichment agents encompassing growth factors, platelet-rich plasma, adipose-derived and bone marrow stem cells, gene therapy, tissue engineering, and other strategies. Data on level of evidence, techniques, complications, and outcomes were collected.

RESULTS

A total of 1382 articles were identified, of which 147 met inclusion criteria. The majority of enrichment strategies demonstrated positive benefit for fat graft survival, particularly with growth factors and adipose-derived stem cell enrichment. Platelet-rich plasma and adipose-derived stem cells had the strongest evidence to support efficacy in human studies and may demonstrate a dose-dependent effect.

CONCLUSIONS

Improved understanding of enrichment strategies contributing to fat graft survival can help to optimize safety and outcomes. Controlled clinical studies are lacking, and future studies should examine factors influencing graft survival through controlled clinical trials in order to establish safety and to obtain consistent outcomes.

What is the Role of Hyaluronic Acid Ester in Myringoplasty? Systematic Review and Meta-Analysis

OBJECTIVE

To reveal odds of tympanic membrane closure and postoperative hearing outcomes for myringoplasty utilizing hyaluronic acid ester via systematic review and meta-analysis.

DATA SOURCES

1) Search of English articles in PubMed/Medline, Embase, and Cochrane databases published between January 1, 1998 and March 31, 2018.

STUDY SELECTION

Inclusion criteria: 1) English language; 2) clinical studies; 3) reported posttreatment perforation status, hearing outcomes, or complications.

EXCLUSION CRITERIA

hyaluronic acid used for middle ear packing or topical application of hyaluronic acid solution.

DATA EXTRACTION

Number of patients, surgical technique, mean age, overall rate of tympanic membrane closure, success rate based on size of perforation, mean air-bone gap improvement, and postoperative speech scores and complications.

DATA SYNTHESIS

Ten studies encompassing 531 patients met criteria. Reported success rates for closure of chronic perforation ranged from 70.0 to 92.7% (mean, 85.21%). Smaller perforation predicted success in complete closure. Mean air-bone gap closure was 10.6 dB (4-24 dB). There were five complications reported. Meta-analysis was performed on five studies. No difference was noted in the success rates between hyaluronic acid ester myringoplasty and conventional tympanoplasty using fascia or perichondrium, with an overall closure rates of 89.8 and 89.4%, respectively (odds ratio [OR] 1.04, 95% confidence interval [CI] 0.59-1.82, p = 0.896). A higher closure rate was seen in hyaluronic acid ester myringoplasty (87.9%) when compared with fat graft myringoplasty (70.8%), (OR 3.01, 95% CI 1.42-6.35, p = 0.004).

CONCLUSIONS

Hyaluronic acid (HA) ester myringoplasty appears to be safe and effective at attaining complete closure of tympanic membrane perforation, although there exists significant selection bias and inconsistent reporting among existing papers.

Hyaluronic acid in otology: Its uses, advantages and drawbacks - A review

OBJECTIVES

Review of the literature for studies involving the use of hyaluronic acid (HA) in otology.

METHODS

Pubmed and OvidMedline were searched using a combination of the following words in different variations: hyaluronic acid, hyaluronate, otolaryngology, otology, ear, tympanic membrane, perforation, tympanostomy, tympanoplasty, myringoplasty, packing, middle ear, cochlea, gene delivery, gene therapy, cochlear implant, hearing loss, meniere, vertigo, otitis and cholesteatoma.

RESULTS

The papers relevant for this review were triaged based on abstracts and titles and were then categorized based on topic/disease entity/procedure. The papers were read and summarized in order to use their findings in this review.

CONCLUSIONS

HA is being recently used as adjuvant therapy for multiple inflammatory conditions and in tissue repair. These immunomodulatory properties and biocompatibility have interested researchers specially in the field of otology for repair, gene delivery, immunomodulation etc. Recent data in the field show optimistic results for the use of HA in several conditions especially tympanic membrane perforations and gene delivery. It also establishes the role of HA as ancillary treatment in many other otologic pathologies. This review presents the most recent findings on the use of HA in otology. The results could be used to guide clinical practice and incite further research based on the presented results of the literature.

Histological Study of The Healing of Traumatic Tympanic Membrane Perforation After Vivosorb and Epifilm Application

BACKGROUND

Untreated traumatic tympanic membrane perforations (TMPs) may lead to permanent perforations and hearing loss. There are many materials that have been previously used for repairing the TMPs.

AIMS AND OBJECTIVES

The purpose of this study is to evaluate the clinical and histological effects of Vivosorb (Vv) and Epifilm on healing of TMPs in a rat model.

MATERIAL AND METHODS

The posterior-inferior quadrant of the tympanic membranes (TMs) in right ears of 14 rats was perforated using a 20-g needle and then the animals were randomly divided into 2 equal groups (n = 7). The perforated right TMs were treated with either Vv (Vv group) or Epifilm (Ep group). The left TMs of 7 rats were perforated in same way and allowed to close spontaneously without any topical material applications (spontaneous closure group as sham control, SC). The left tympanic membranes of the other 7 rats were not perforated and used as normal controls (NC group). On postoperative 15th day, tympanic bullas were extracted from killed rats and examined morphometrically and histopathologically.

RESULTS

Perforation closure rate was 85.7% (6/7) in both Vv and SC groups. Perforations of Ep group closed in 7/7 (100%) ears. The thicknesses of the perforated membranes were increased in SC and especially Vv groups. Also, connective tissue fibrosis, blood clots, and epithelial degenerations were detected in SC and Vv groups. The mean fibroblastic reaction scores of Vv, Ep, and SC groups were 2.14(+), 0.57(+), and 1.71(+) respectively, on comparison with NC group. The mean neovascularization score was 1.42(+) in Vv group, 0.14(+) in Ep group, and 0.57(+) in SC group.

CONCLUSION AND SIGNIFICANCE

Vivosorb and especially Epifilm can improve the healing process in traumatic TMPs and additionally, Epifilm might be more preferred for the treatment of TMPs because of causing lesser fibrosis.

Botulinum toxin A improves adipose tissue engraftment by promoting cell proliferation, adipogenesis and angiogenesis

Adipose tissue engraftment has become a well-established therapy in plastic and reconstructive surgery used to restore age-related or injury-related soft tissue loss. However, the unpredictable absorption rates limit its further application. Some clinicians have noted that more optimal aesthetic results are achieved when botulinum toxin A (BoNTA) is applied prior to adipose tissue grafting. In the present study, we transplanted allogeneic adipose tissue treated with or without BoNTA in SD rats in vivo. We subsequently evaluated the survival rate (weight, volume, apoptosis and cellular integrity) and revascularization of the adipose tissue. The results revealed that BoNTA improved the long-term weight and volume retention of the graft, and preserved cellular integrity. BoNTA significantly increased the expression levels of CD31 and vascular endothelial growth factor (VEGF), suggesting enhanced vasodilation and endothelial cell proliferation. In vitro, adipose-derived stem cells (ASCs) were isolated, identified and induced to proliferate and differentiate with or without BoNTA. Furthermore, to evaluate the proliferative, adipogenic and angiogenic ability of the ASCs, CCK-8 assay and Oil Red O staining were conducted. Gene and protein expression levels were analyzed by RT-qPCR and western blot analysis. The results revealed that 8×10⁻² U/ml BoNTA as the optimal dose increased ASC proliferation and adipogenic differentiation capacity, as well as the expression level of the key cytokine of angiogenesis. On the whole, our findings indicate that BoNTA improves adipose tissue engraftment and promotes ASC regeneration, which could benefit future clinical applications.

Hyaluronic Acid Fat Graft Myringoplasty Versus Autologous Platelet Rich Plasma

BACKGROUND

Hyaluronic acid fat graft myringoplasty (HAFGM) is an office-based technique for tympanic membrane perforation (TMP) treatment. It is simple, inexpensive, and performed under local anesthesia at the outpatient office department. We aimed to compare HAFGM technique to a recently described topical use of autologous platelet rich plasma myringoplasty (PRPM) in the repair of TMP. We also aimed to assess the hearing level improvement postoperatively.

METHODS

We conducted a prospective study in an adult tertiary care center between January 2015 and January 2016. Adult patients presenting with simple TMP were operated randomly using either HAFGM or PRPM under local anesthesia in an office-based setting. Perforations were classified into four grades. Success was considered when complete closure is achieved. Audiometric parameters were evaluated pre- and postoperatively.

RESULTS

We included 27 patients, of whom 16 were operated with HAFGM and 11 were operated with PRPM. Complete closure was achieved in 81.2% and 18.1%, respectively. Postoperatively, no worsening of bone conduction threshold was noted. The study was abandoned due to the low success rate in patients with PRPM. The pure tone audiometry was improved postoperatively in patients with closed tympanic membrane.

CONCLUSIONS

The study was aborted because of the unsatisfactory obtained results using PRPM. It confirms once again the beneficial effect of hyaluronic acid in the healing process when added to fat graft myringoplasty. Furthermore, it requires no hospitalization.

Hyaluronan and hyaluronidase, which is better for embryo development?

Our aim was to examine size-specific effects of Hyaluronan (HA) on preimplantation embryo development. We investigated the effects of Hyalovet (HA, 500-750 kDa; the size produced by HA synthase-3, which is abundant in the oviduct), or HA treated with Hyaluronidase-2 (Hyal2; also expressed in the oviduct that breaks down HA into 20 kDa fragments). In experiment 1 (in vivo), oviducts of synchronized and superovulated ewes (n = 20) were surgically exposed on Day 2 post-mating, ligated, and infused with either Hyalovet, Hyalovet + Hyal2, Hyal2, or PBS (control). Ewes were killed 5 days later for recovery of embryos and oviductal epithelial cells (OEC). Blastocyst rates were significantly higher in Hyal2 and Hyalovet + Hyal2 oviducts. Hyaluronidase-2 infusion resulted in higher blastocyst cell numbers and hatching rates. This was associated with increased HSP70 expression in OEC. In contrast, Hyalovet resulted in the lowest development to blastocyst stage and lowest hatching rates, and decreased IGF2 and IGFBP2 expression in OEC. IGF1 and IL1α expression were not affected. In experiment 2, to rule out indirect effects of oviductal factors, ovine embryos were produced and cultured with the same treatments in vitro from Day 2 to 8. Hyaluronidase-2, but not Hyalovet, enhanced blastocyst formation and reduced inner cell mass apoptosis. Hyalovet inhibited hatching. In conclusion, the presence of large-size HA (500-750 kDa) in the vicinity of developing embryos appears to disturb the oviductal environment and embryo development in vivo and in vitro. In contrast, we show evidence that breakdown of HA into smaller fragments is required to maximize embryo development and blastocyst quality.