A new method for closing tympanic membrane perforations using basic fibroblast growth factor

In Vitro Assessment of Wound-Healing Efficacy of Stabilized Basic Fibroblast Growth Factor (FGF-2) Solutions

Chronic tympanic membrane perforations (TMP) pose a significant clinical challenge, but basic fibroblast growth factor (FGF-2) shows promise for their treatment, despite its instability in aqueous solutions which hampers the sustained delivery crucial for the healing process. Addressing this, our research focused on the development of stabilized FGF-2 formulations, F5 and F6, incorporating dual, generally regarded as safe (GRAS) excipients to enhance stability and therapeutic efficacy. F5 combined FGF-2 (1600 ng/mL) with 0.05% w/v methylcellulose (MC) and 20 mM alanine, while F6 used FGF-2 with 0.05% w/v MC and 1 mg/mL human serum albumin (HSA). Our findings demonstrate that these novel formulations not only significantly improve the cytoproliferation of human dermal fibroblasts but also exhibit the most potent chemoattractant effects, leading to the highest fibroblast monolayer closure rates (92.5% for F5 and 94.1% for F6 within 24 h) compared to other FGF-2 solutions tested. The comparable performance of F5 and F6 underscores their potential as innovative, less invasive, and cost-effective options for developing otic medicinal products aimed at the effective treatment of chronic TMP.

Overcoming barriers: a review on innovations in drug delivery to the middle and inner ear

Despite significant advances in the development of therapeutics for hearing loss, drug delivery to the middle and inner ear remains a challenge. As conventional oral or intravascular administration are ineffective due to poor bioavailability and impermeability of the blood-labyrinth-barrier, localized delivery is becoming a preferable approach for certain drugs. Even then, localized delivery to the ear precludes continual drug delivery due to the invasive and potentially traumatic procedures required to access the middle and inner ear. To address this, the preclinical development of controlled release therapeutics and drug delivery devices have greatly advanced, with some now showing promise clinically. This review will discuss the existing challenges in drug development for treating the most prevalent and damaging hearing disorders, in particular otitis media, perforation of the tympanic membrane, cholesteatoma and sensorineural hearing loss. We will then address novel developments in drug delivery that address these including novel controlled release therapeutics such as hydrogel and nanotechnology and finally, novel device delivery approaches such as microfluidic systems and cochlear prosthesis-mediated delivery. The aim of this review is to investigate how drugs can reach the middle and inner ear more efficiently and how recent innovations could be applied in aiding drug delivery in certain pathologic contexts.

Comparing Myringoplasty to Type I Tympanoplasty in Tympanic Membrane Repair: A Systematic Review and Meta-Analysis

OBJECTIVE

To compare the anatomic success rates of type I tympanoplasty (tympanoplasty) versus myringoplasty. By our definition, tympanoplasty involves entering the middle ear via elevation of a tympanomeatal flap, while myringoplasty involves surgery to the drumhead without middle ear exposure.

DATA SOURCES

PubMed, Scopus, CINAHL, Cochrane.

REVIEW METHODS

To be included, studies must have documented surgical technique, tympanic membrane (TM) perforation size (as % of TM), and success rate using tissue or alloplastic grafts. Exclusion criteria included series with more than 10% of patients with cholesteatoma or middle ear pathology. A meta-analysis of weighted summary proportions under the random effects model was performed, and proportion differences (PD) were calculated. A secondary analysis of hearing outcomes was performed.

RESULTS

Eighty-five studies met inclusion, with a tympanoplasty cohort of n = 7966 and n = 1759 for myringoplasty. For perforations, less than 50% of the TM, the success rate for tympanoplasty and myringoplasty was 90.2% and 91.4%, respectively (PD: 1.2%, p = .19). In perforations greater than 50%, tympanoplasty and myringoplasty success rates were 82.8% and 85.3%, respectively (PD: 2.5%, p = .29). For both procedures, perforations less than 50% of the TM had higher success rates than perforations greater than 50% of the TM (p < .01). Both techniques endorsed significant improvements to air-bone gap (ABG) metrics.

CONCLUSION

Our analysis suggests that the anatomic success rate is similar for tympanoplasty and myringoplasty, regardless of perforation size, and that smaller perforations experience higher success rates in both techniques. ABG outcomes were also similar between procedure techniques.

Molecular and Clinical Significance of Fibroblast Growth Factor 2 in Development and Regeneration of the Auditory System

The fibroblast growth factor 2 (FGF2) is a member of the FGF family which is involved in key biological processes including development, cellular proliferation, wound healing, and angiogenesis. Although the utility of the FGF family as therapeutic agents has attracted attention, and FGF2 has been studied in several clinical contexts, there remains an incomplete understanding of the molecular and clinical function of FGF2 in the auditory system. In this review, we highlight the role of FGF2 in inner ear development and hearing protection and present relevant clinical studies for tympanic membrane (TM) repair. We conclude by discussing the future implications of FGF2 as a potential therapeutic agent.

FGF2 and EGF for the Regeneration of Tympanic Membrane: A Systematic Review

Objective

A systematic review was conducted to compare the effectiveness and safety of fibroblast growth factor-2 (FGF2) and epidermal growth factor (EGF) for regeneration of the tympanic membrane (TM).

Methods

The PubMed database was searched for relevant studies. Experimental and clinical studies reporting acute and chronic TM perforations in relation to two healing outcomes (success rate and closure time) and complications were selected.

Results

A total of 47 studies were included. Five experimental studies showed closure rates of 55%-100% with FGF2 compared with 10%-62.5% in controls for acute perforations. Five experimental studies showed closure rates of 30.3%-100% with EGF and 3.6%-41% in controls for chronic perforations. Two experimental studies showed closure rates of 31.6% or 85.7% with FGF2 and 15.8% or 100% with EGF. Nine clinical studies of acute large perforations showed closure rates of 91.4%-100% with FGF2 or EGF. Two clinical studies showed similar closure rates between groups treated with FGF2 and EGF. Seven clinical studies showed closure rates of 88.9%-100% within 3 months and 58%-66% within 12 months using FGF2 in repair of chronic perforations, but only one study showed a significantly higher closure rate in the saline group compared with the FGF2 group (71.4% vs. 57.5%, respectively, P = 0.547). In addition, three experimental studies showed no ototoxicity associated with FGF2 or EGF. No middle ear cholesteatoma or epithelial pearls were reported, except in one experimental study and one clinical study, respectively.

Conclusions

FGF2 and EGF showed good effects and reliable safety for the regeneration of TM. In addition, EGF was better for the regeneration of acute perforations, while FGF2 combined with biological scaffolds was superior to EGF for chronic perforations, but was associated with high rates of reperforation over time. Further studies are required to determine whether EGF or FGF2 is better for TM regeneration.

The effectiveness and safety of growth factors in the treatment of tympanic membrane perforations: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

To determine the clinical efficacy and safety of growth factors in the treatment of tympanic membrane (TM) perforations from randomized controlled trials (RCTs).

METHODS

Databases, including PubMed, EMBASE, Cochrane library, Ebsco, Ovid, Scopus, and Web of Science, were searched for articles in any language about studies on the treatment of TM perforations with growth factors. Inclusion criteria were: (1) randomized controlled trials (RCTs); (2) only patients with TM perforations included; and (3) any kinds of growth factors or related products were used as an intervention. Exclusion criteria were: (1) study was not reported as a full paper, only as an abstract; (2) review studies and case reports; and (3) an inability to extract valid data. Outcomes of interest included perforation closure rate, closure time, hearing improvement, and complications.

RESULTS

Nineteen RCTs with a total of 1335 participants were included. Growth factors effectively increased the rate of perforation closure [risk ratio (RR): 1.21 95% confidence interval (1.12, 1.30), p < 0.01] and shortened closure time [mean difference (MD): - 16.71 (- 22.74, - 10.15), p < 0.01]. There was no significant difference in hearing improvement [MD: 0.10 (- 0.50, 0.70), p = 0.74] or complications [RR: 1.49 (0.96, 2.32), p = 0.07] between the growth factor intervention group and the control group.

CONCLUSION

Growth factors are effective and safe in the treatment of TM perforations. However, better designed clinical trials should be carried out in the future to obtain more robust findings about the effectiveness of growth factors in the treatment of TM perforations.

Topical Application of bFGF Alone for the Regeneration of Chronic Tympanic Membrane Perforations: A Preliminary Case Series

Results

A total of 29 patients consisting 13 in the bFGF alone group and 16 in the myringoplasty group were finally included in the analysis. Of the 13 patients in the bFGF alone group, the perforations were small in 6 and medium in 7; the etiology was secondary to COM in 11 and to trauma in 2. One patient with an unhealed perforation continued bFGF treatment until 6 months, while the others stopped at 3 months. Of the seven medium-sized perforations, none of the five COM perforations closed, while the two traumatic perforations achieved complete closure within 2 and 4 weeks, respectively. The successful closure rate was 28.6% (2/7). Successful closure was achieved in 66.7% (4/6) of the six small perforations with COM, with a mean closure time of 4.75 weeks. Of the 16 patients in the myringoplasty group, all perforations were medium-sized and were secondary to COM in 15 cases and traumatic in 1 case; all achieved complete closure.

Conclusions

bFGF alone facilitated the repair of chronic traumatic perforations and small perforations with COM, but not medium-sized perforations with COM. These observations indicated that the regenerative conditions of traumatic perforations are better than those of COM perforations when using bFGF alone, and that graft materials could play a critical role in the regeneration of larger-sized chronic perforations with COM.

The Effectiveness of bFGF in the Treatment of Tympanic Membrane Perforations: A Systematic Review and Meta-Analysis

Objective:

To investigate the effectiveness of basic fibroblast growth factor (bFGF) versus placebo or no intervention in the treatment of tympanic membrane (TM) perforations from randomized controlled trials (RCTs), prospective and retrospective studies.

Data Sources:

PubMed, EMBASE, and Cochrane databases were screened from their inceptions to June 2019.

Study Selection:

Inclusion criteria: 1) English language; 2) observational (retrospective or prospective) or treatment (RCT) studies; 3) reported the outcomes on the application of bFGF in adult or pediatric population. Exclusion criteria: 1) studies without a control group; 2) animal studies, in vitro studies, review studies, and case reports.

Data Extraction:

Number of patients, cause of TM perforation, perforation size, treatment, mean age, follow-up time, sex, closure rate, healing time, mean air-bone gap improvement.

Data Synthesis:

A total of 14 studies were included, including seven RCTs and seven non-RCTs with a total of 1,072 participants. The odds ratio for closure rate of bFGF treatment was 7.33 (95% confidence interval [CI], 4.65 to 11.53; p < 0.01; I² = 44%) and the standardized mean difference (SMD) for healing time was –5.89 (95% CI: –7.85 to –3.93, p < 0.01, I² = 98%), suggesting bFGF application has a significant effect on closure of TM perforations. However, no significant change in hearing (SMD: 0.08, 95% CI: –0.11 to 0.27, p = 0.39, I² = 0%) was seen as a result of bFGF treatment.

Conclusions:

Our meta-analysis has revealed that the application of bFGF can significantly enhance the closure rate as well as shorten the healing time for TM perforations. In terms of hearing, there is as yet no evidence that bFGF has a significant effect. Given its ease, availability, and safety, bFGF can be used effectively for TM repair.

Acellular Collagen Scaffold With Basic Fibroblast Growth Factor for Repair of Traumatic Tympanic Membrane Perforation in a Rat Model

OBJECTIVE

To evaluate the efficacy of acellular collagen scaffold (ACS) in combination with basic fibroblast growth factor (bFGF) for the repair of traumatic tympanic membrane (TM) perforation in a rat model.

STUDY DESIGN

A prospective controlled animal study in a rat model of traumatic TM perforation.

SETTING

Tertiary medical center.

SUBJECTS AND METHODS

Sprague-Dawley rats (N = 84) with unilateral traumatic perforation of the right TMs were randomized to receive ACS, bFGF, ACS in combination with bFGF (ACS/bFGF), or nothing (spontaneous healing without any interventions as a control group). The healing outcomes were evaluated by otoscopy, optical coherence tomography, histology, and transmission electron microscopy at 1, 2, and 4 weeks postoperatively. The hearing outcomes were assessed with auditory brainstem response testing.

RESULTS

ACS/bFGF resulted in higher perforation closure rates at an earlier stage than spontaneous healing, ACS, and bFGF. Based on histology, optical coherence tomography, and transmission electron microscopy, a trilaminar structure and uniform thickness with mature, densely packed collagen fibers were seen in the ACS/bFGF group. Auditory brainstem response evaluation also showed that ACS/bFGF treatment promoted faster functional hearing recovery as compared with the control group.

CONCLUSIONS

ACS is an effective TM scaffold and a carrier for bFGF. ACS/bFGF improves the TM closure rate, results in better-reconstructed TMs, and improves hearing. ACS/bFGF serves as a potential substitute for TM perforations in clinical settings.

A Hierarchy of Proliferative and Migratory Keratinocytes Maintains the Tympanic Membrane

The tympanic membrane (TM) is critical for hearing and requires continuous clearing of cellular debris, but little is known about homeostatic mechanisms in the TM epidermis. Using single-cell RNA sequencing, lineage tracing, whole-organ explant, and live-cell imaging, we show that homeostatic TM epidermis is distinct from other epidermal sites and has discrete proliferative zones with a three-dimensional hierarchy of multiple keratinocyte populations. TM stem cells reside in a discrete location of the superior TM and generate long-lived clones and committed progenitors (CPs). CP clones exhibit lateral migration, and their proliferative capacity is supported by Pdgfra+ fibroblasts, generating migratory but non-proliferative progeny. Single-cell sequencing of the human TM revealed similar cell types and transcriptional programming. Thus, during homeostasis, TM keratinocytes transit through a proliferative CP state and exhibit directional lateral migration. This work forms a foundation for understanding TM disorders and modeling keratinocyte biology.

State of the art regeneration of the tympanic membrane

PURPOSE OF REVIEW

One of the most common diseases of the tympanic membrane is a perforation, and tympanoplasty is one of the more common procedures in otolaryngology. Tympanic membrane regeneration and bioengineering aim to improve the success rate of the procedure, increase the availability of different scaffolds and provide innovative tools that will simplify the surgical technique and make it accessible for surgeons with varying expertise level. This review aims to raise awareness of current tissue engineering developments in tympanic membrane regeneration and how they may augment current clinical practices. We focus here on achievements in tympanic membrane cell cultures and on innovations in development of new scaffolds and growth factors that enhance regeneration of patient's native tympanic membranes.

RECENT FINDINGS

In recent years, great achievements were reached in the field of tympanic membrane regeneration in the three hallmarks of bioengineering: cells, scaffolds and bioactive molecules. New techniques for modeling normal tympanic membrane proliferation were developed, as well as for isolation and expansion of normal tympanic membrane keratinocytes from miniature samples of scarred tissue. Ongoing clinical trials aim to seal the perforation by applying different scaffolds infiltrated by growth factors on the tympanic membrane.

SUMMARY

Research efforts in tympanic membrane regeneration continue to seek the ideal single tissue-engineered substitute. Recent advances in tympanic membrane bioengineering include new types of scaffolds that may augment and provide a safe and effective alternative to the current gold-standard autograft. New bioactive molecules may simplify the surgical procedure and reduce surgical time by augmenting the native tympanic membrane regeneration. Several groups of bioengineering scientists and neurotologists are continuing to move forward and develop new strategies, seeking to create a fully functional tissue-engineered tympanic membrane.

A Systematic Review of Nonautologous Graft Materials Used in Human Tympanoplasty

OBJECTIVES

Nonautologous graft materials may solve several dilemmas in tympanoplasty by obviating the need for graft harvest, facilitating consistent wound healing, and permitting graft placement in the clinical setting. Prior studies of nonautologous grafts in humans have shown variable outcomes. In this systematic review, we aim to 1) summarize clinical outcomes and 2) discuss limitations in the literature regarding nonautologous grafts for tympanoplasty in humans.

METHODS

A literature review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. The study size, etiology and duration of perforation, type of nonautologous graft, and postoperative closure rate were assessed.

RESULTS

The PRISMA approach yielded 61 articles, including 3,247 ears that met inclusion criteria. Studies evaluated nonautologous grafts including paper patch, gelatin sponge, growth factors, porcine small-intestinal submucosa, among others. Traumatic perforations (62.3%) were most commonly studied, whereas postinfectious perforations (31.9%) and other etiologies (5.8%) comprised a minority of cases. Acute perforations of <8 weeks duration constituted just over half of all treated ears. Overall closure rate was 82.1%, with significantly higher closure rates in acute (89.9%) versus chronic perforations (64.9%, P < .01), regardless of material. A median postoperative air-bone gap of 5.6 dB was found in the 23% of studies reporting this metric.

CONCLUSIONS

The majority of publications reviewing nonautologous materials in tympanoplasty evaluate acute or traumatic perforations, and few rigorously report hearing outcomes. Given available data, porcine submucosa and basic fibroblast growth factor may hold promise for chronic perforation closure. Future studies should report closure rates and hearing outcomes in perforations >8 weeks duration. Laryngoscope, 131:392-400, 2021.

Atelocollagen Application in Human Periodontal Tissue Treatment-A Pilot Study

Background: The aim of this study is the clinical observation of gingival tissue condition after atelocollagen injection. Methods: In 18 patients, 97 gingival class I Miller recessions were divided according to recession height, gingival papillae loss and thickness of gingivae. Atelocollagen (Linerase, 100 mg) was injected into keratinized gingivae twice or thrice, at two-week intervals. Results: Statistically significant changes in gingival recession, amount of gingival papillae loss and thickness of gingiva were observed, after both two and three collagen injections. Although the degree (height) of recession decreased and gingival tissue thickness increased with every injection; there was no difference in gingival papillae loss between second and third collagen injections. Conclusions: The injectable form of atelocollagen is a promising material for gingival soft tissue regeneration and stimulation and allows for reduction in the number of procedures and support in a variety of surgical scenarios. This is a pilot study that clinically measures the impact of injected atelocollagen on periodontal tissue biotype, including the thickness of gingivae and gingival papillae regeneration.

3D printing for tissue engineering in otolaryngology

Airway and other head and neck disorders affect hundreds of thousands of patients each year and most require surgical intervention. Among these, congenital deformity that affects newborns is particularly serious and can be life-threatening. In these cases, reconstructive surgery is resolutive but bears significant limitations, including the donor site morbidity and limited available tissue. In this context, tissue engineering represents a promising alternative approach for the surgical treatment of otolaryngologic disorders. In particular, 3D printing coupled with advanced imaging technologies offers the unique opportunity to reproduce the complex anatomy of native ear, nose, and throat, with its import in terms of functionality as well as aesthetics and the associated patient well-being. In this review, we provide a general overview of the main ear, nose and throat disorders and focus on the most recent scientific literature on 3D printing and bioprinting for their treatment.

Fibroblast growth factor-2 stimulates proliferation of human adipose-derived stem cells via Src activation

Background

Human adipose-derived stem cells (hASCs) are a subset of mesenchymal stem cells (MSCs); it has been regarded as one of the most promising stem cells. We previously found that fibroblast growth factor-2 (FGF-2) enhanced the proliferation and differentiation of hASC. However, the mechanisms involved in the growth of hASCs by FGF-2 have not been investigated.

Methods

Human adipose-derived stem cells (hASCs) were cultured with FGF-2, and cell growth was assessed. Effects of FGF Receptor (FGFR) inhibitor (NVP-BGJ398), ERK1/2 inhibitor (PD98059), PI3K/Akt inhibitor (LY294002), JNK inhibitor (SP600125), and p38 MAPK inhibitor (SB203580) and Src inhibitor (PP1) on the proliferation were investigated. At the same time, we assessed the effect of FGFR inhibitor on several signaling enzymes such as ERK1/2, JNK, p38, and Akt, in protein level. The involvement of Src activation by FGF-2 was also examined.

Results

FGF-2 markedly promoted proliferation of hASCs at concentrations lower than 10 ng/ml and stimulated cell progression to the S and G2/M phases. Proliferation was blocked by the FGFR inhibitor (NVP-BGJ398) and various signaling pathway inhibitors, such as Erk1/2 inhibitor (PD98059), PI3K/Akt inhibitor (LY294002), JNK inhibitor (SP600125), and p38MAPK inhibitor (SB203580). The FGFR inhibitor reduced the activation of protein kinases, such as AKT, Erk1/2, JNK, and p38, in several signaling pathways. The downstream kinase of FGFR, Src, was activated by FGF-2, and its activation was canceled by the FGFR inhibitor. MEK1/2, a downstream kinase of Src, was parallelly regulated by FGF-2. The Src inhibitor (PP1) markedly blocked the proliferation of hASCs via inhibition of Src and MEK1/2.

Conclusion

Src activation is indispensable for FGF-2-mediated proliferation of ASCs, as well as the subsequent activation of multi-signaling pathways.

Prognostic factors of myringoplasty: study of a 140 cases series and review of the literature

Myringoplasty is one of the most frequent interventions in otology. It aims to restore the eardrum in order to protect against extrinsic contamination by water and to improve hearing. Our study aimed to analyze the factors that may affect anatomical and functional results of myringoplasty or type I tympanoplasty. A retrospective study was performed of a series of 140 cases of myringoplasty over a 6-years period from 2010 to 2015. The approach was post-auricular in 69% of cases and all the patients underwent an underlay technique. Temporal fascia was used in 90.71% of the cases. After an average follow-up of 13 months, the anatomical and functional results were acceptable, with a tympanic closure rate of 88% and an average audiometric gain of 14.22 dB. Several factors affected our results, including the location of the perforation, the active or inactive status of the chronic otitis media, the condition of the opposite ear and the graft material. In light of our results and those of the literature, we believe that the middle ear should be dry at least two months prior to surgery, use of cartilaginous graft material and underlay technique should be preferred and special precautions should be taken in case of anterior or contralateral perforation.

Regeneration of the tympanic membrane using fibroblast growth factor-2

OBJECTIVE

A systematic review was conducted to investigate the effectiveness of fibroblast growth factor-2 on the regeneration of tympanic membrane perforation.

METHODS

The PubMed database was searched for relevant studies. Experimental studies, human randomised controlled trials, prospective single-arm studies and retrospective studies reporting acute and chronic tympanic membrane perforations in relation to two healing outcomes (success rate and closure time), were selected.

RESULTS

All 11 clinical studies investigating the effect of fibroblast growth factor-2 on traumatic tympanic membrane perforations in humans reported a success rate of 89.3-100 per cent, with a closure time of around 2 weeks. Three studies of fibroblast growth factor-2 combined with Gelfoam showed that the success rate of chronic tympanic membrane perforation was 83-98.1 per cent in the fibroblast growth factor-2 group, but 10 per cent in the gelatine sponge groups.

CONCLUSION

Fibroblast growth factor-2 with or without biological material patching promotes regeneration in cases of acute and chronic tympanic membrane perforation, and is safe and efficient. However, the best dosage, application time and administration pathway of fibroblast growth factor-2 are still to be elucidated.

Implementation of the hyaluronic acid fat graft myringoplasty technique, pitfalls and lessons learned

BACKGROUND

Myringoplasty is a common procedure in otorhinolaryngology. Many techniques with different complications and outcomes have been described, one of which is hyaluronic acid fat graft myringoplasty (HAFGM). This technique, as proposed by Saliba, uses fat tissue and hyaluronic acid discs. The technique is relatively fast with a high success rate and low complications. However, what outcomes can be expected when performed by other surgeons? In this paper, we report on the technique's success in our own hands.

MATERIALS AND METHODS

Based on Saliba's protocol, we performed 86 HAFGMs by a transcanal approach between 2012 and August 2014. However, our 70% success rate was significantly different from Saliba's 92% (p value 2.8e - 05). We visited Saliba's clinic in order to identify critical differences between our approaches. We adapted the differences we found in our protocol and analysed another 50 HAFGMs performed afterwards, between October 2014 and December 2015.

RESULTS

The success rate increased to 86-89%, this percentage is not different compared to Saliba's results (p value .25 and .54).

CONCLUSION

HAFGM is a reproducible technique in the hands of other surgeons, but critical following of the surgical protocol is important.

Functional Outcomes of Heparin-Binding Epidermal Growth Factor-Like Growth Factor for Regeneration of Chronic Tympanic Membrane Perforations in Mice

We aim to demonstrate that regeneration of chronic tympanic perforations with heparin-binding epidermal growth factor-like growth factor (HB-EGF) delivered by an injectable hydrogel restored hearing to levels similar to that of nonperforated tympanic membranes. Chronic tympanic membrane perforation is currently managed as an outpatient surgery with tympanoplasty. Due to the costs of this procedure in the developed world and a lack of accessibility and resources in developing countries, there is a great need for a new treatment that does not require surgery. In this study, we show in a mouse model through measurement of auditory brainstem response and distortion product otoacoustic emissions that tympanic perforations lead to hearing loss and this can be predominantly recovered with HB-EGF treatment (5 μg/mL). Our animal model suggests a return to function between 2 and 6 months after treatment. Auditory brainstem response thresholds had returned to the control levels at 2 months, but the distortion product otoacoustic emissions returned between 2 and 6 months. We also show how the vibration characteristics of the regenerated tympanic membrane, as measured by laser Doppler vibrometry, can be similar to that of an unperforated tympanic membrane. Using the best available methods for preclinical evaluation in animal models, it is likely that HB-EGF-like growth factor treatment leads to regeneration of chronic tympanic membrane perforations and restoration of the tympanic membrane to normal function, suggesting a potential route for nonsurgical treatment.

Regenerative treatment for tympanic membrane perforation using gelatin sponge with basic fibroblast growth factor

OBJECTIVE

The objective of this study was to evaluate safety and efficacy of regenerative treatment using gelatin sponge with basic fibroblast growth factor (bFGF) in patients with tympanic membrane perforation (TMP).

METHODS

The current study was a prospective, multicenter, open-label, single-arm, and exploratory clinical trial to evaluate the safety and efficacy of the TM regeneration procedure (TMRP). Myringotomy was used to mechanically disrupt the edge of the TMP, and a gelatin sponge immersed in bFGF was then placed over the perforation. Fibrin glue was dripped over the sponge as a sealant. TMP closure was examined 4 weeks later and, if insufficient, TMRP was repeated a maximum of three more times. TMP closure and hearing improvement 12 weeks after the final TMRP as well as safety were evaluated.

RESULTS

Of the 11 patients with TMP who participated in this study, one who fulfilled the exclusion criteria and did not undergo TMRP and one with cholesteatoma were excluded from the efficacy analysis. TMP closure and hearing improvement 12 weeks after the final TMRP were achieved in eight out of nine patients (88.9%). Mean bone conduction threshold significantly improved 12 weeks after the TMRP compared with baseline (35.7±20.3 vs 29.4±21.0dB, P=0.015). Six out of ten patients receiving TMRP experienced temporary adverse events: appendicitis (serious, severe), otorrhea (mild), otitis media (mild), and sudden hearing loss (mild). However, none were related to the protocol treatment.

CONCLUSION

TMP closure and hearing improvement were frequently confirmed following the TMRPs which were safely performed. These favorable outcomes were accompanied with significant improvement of the bone conduction threshold. These promising outcomes would encourage a large-scaled, randomized and pivotal clinical trial in the future. This trial is registered at http://www.umin.ac.jp/ctr/index.htm (identifier: UMIN000006585).

Mesenchymal stem cell-laden hybrid scaffold for regenerating subacute tympanic membrane perforation

Tympanic membrane (TM) perforation is one of the most common otology complications. To date, there has not been reported TM regeneration using bioprinted scaffold. The purpose of this study was to evaluate the efficacy and feasibility of bioprinted polycaprolactone/collagen/alginate-mesenchymal stem cell (PCAMSC) scaffolds for the regeneration of subacute TM perforation. Sprague-Dawley rats were used in an animal model of subacute TM perforation. In the experimental group (n=7), bioprinted 3D PCAMSC scaffold was placed on the perforation. The control group (n=7) were treated with polycaprolactone/collagen/alginate (PCA) scaffold. Healing time, acoustic-mechanical properties, and morphological analysis were performed by otoendoscopy, auditory brainstem response (ABR), single-point laser doppler vibrometer (LDV), optical coherence tomography (OCT), and light microscopic evaluation. The closure of the TM perforation was achieved in 100% of the experimental group vs. 72% of the control group, and this difference was statistically significant (p<0.05). The ABR threshold at all frequencies of the experimental group was recovered to the normal level compared to the control group. TM vibration velocity in the experimental group recovered similar to the normal control level. The difference are very small and they are not statistically significant below 1kHz (p=0.074). By OCT and light microscopic examination, regenerated TM of the experimental group showed thickened fibrous and mucosal layer. In contrast, the control group showed well regenerated but less thickened than experimental group. From these results, the cell-laden PCAMSC scaffold offers a significant advantage in the TM regeneration in a rat subacute TM perforation model. It may offer attractive opportunities in the conservative clinical treatment.

No systemic exposure of transtympanic heparin-binding epidermal growth factor like growth factor

CONTEXT

Heparin-binding epidermal growth factor like growth factor (HB-EGF) is an emerging therapeutic for the regeneration of the tympanic membrane (TM).

OBJECTIVE

Our aim was to determine whether the doses of HB-EGF delivered in a sustained release hydrogel into a middle ear mouse model, would be measurable in the systemic circulation. We also aimed to observe, in the scenario that the intended dose was absorbed directly into the circulation, whether these levels could be measured above the background levels of HB-EGF in the circulation.

METHODS

A total of 12 mice had transtympanic injections of 5 μg/ml of HB-EGF contained within a previously described novel hydrogel vehicle, while another 12 mice had intravenous delivery of 10 μg/kg of HB-EGF. Intravenous blood samples were collected at 0-, 3-, 24-, 168-, 288- and 720-h post-injection. A double-antibody sandwich one-step process enzyme-linked immunosorbent assay (ELISA) was used to determine the level of HB-EGF in the serum.

RESULTS

No mice in the transtympanic administration group and no mice in the intravenous administration group were found to have blood level measured above that in the controls.

DISCUSSION

The inability of the positive control to measure levels above background, suggest the total dose used in our studies, even if 100% absorbed into the system circulation is insignificant.

CONCLUSIONS

HB-EGF at the doses and delivery method proposed for treatment of chronic TM perforation in a mouse model are likely to have no measurable systemic effect.

Heparin Binding Epidermal Growth Factor-Like Growth Factor Heals Chronic Tympanic Membrane Perforations With Advantage Over Fibroblast Growth Factor 2 and Epidermal Growth Factor in an Animal Model

HYPOTHESIS

That heparin binding epidermal growth factor-like growth factor (HB-EGF) heals chronic tympanic membrane (TM) perforations at higher rates than fibroblast growth factor 2 (FGF2) and epidermal growth factor (EGF) in an animal model.

BACKGROUND

A nonsurgical treatment for chronic TM perforation would benefit those unable to access surgery or those unable to have surgery, as well as reducing the cost of tympanoplasty. Growth factor (GF) treatments have been reported in the literature with variable success with the lack of a suitable animal providing a major obstacle.

METHODS

The GFs were tested in a validated mouse model of chronic TM perforation. A bioabsorbable hydrogel polymer was used to deliver the GF at a steady concentration as it dissolved over 4 weeks. A control (polymer only, n = 18) was compared to polymer loaded with HB-EGF (5 μg/ml, n = 18), FGF2 (100 μg/ml, n = 19), and EGF (250 μg/ml, n = 19). Perforations were inspected at 4 weeks.

RESULTS

The healing rates, as defined as 100% perforation closure, were control (5/18, 27.8%), HB-EGF (15/18, 83.3%), FGF2 (6/19, 31.6%), and EGF (3/19, 15.8%). There were no differences between FGF2 (p = 0.80) and EGF (p = 0.31) with control healing rates. HB-EGF (p = 0.000001) showed a significant difference for healing. The HB-EGF healed TMs showed layers similar to a normal TM, whereas the other groups showed a lack of epithelial migration.

CONCLUSION

This study confirms the advantage of HB-EGF over two other commonly used growth factors and is a promising nonsurgical treatment of chronic TM perforations.

Heparin binding-epidermal growth factor-like growth factor for the regeneration of chronic tympanic membrane perforations in mice

We aim to explore the role of epidermal growth factor (EGF) ligand shedding in tympanic membrane wound healing and to investigate the translation of its modulation in tissue engineering of chronic tympanic membrane perforations. Chronic suppurative otitis media (CSOM) is an infected chronic tympanic membrane perforation. Up to 200 million suffer from its associated hearing loss and it is the most common cause of pediatric hearing loss in developing countries. There is a need for nonsurgical treatment due to a worldwide lack of resources. In this study, we show that EGF ligand shedding is essential for tympanic membrane healing as it's inhibition, with KB-R7785, leads to chronic perforation in 87.9% (n=58) compared with 0% (n=20) of controls. We then show that heparin binding-EGF-like growth factor (5 μg/mL), which acts to shed EGF ligands, can regenerate chronic perforations in mouse models with 92% (22 of 24) compared with 38% (10 of 26), also with eustachian tube occlusion with 94% (18 of 19) compared with 9% (2 of 23) and with CSOM 100% (16 of 16) compared with 41% (7 of 17). We also show the nonototoxicity of this treatment and its hydrogel delivery vehicle. This provides preliminary data for a clinical trial where it could be delivered by nonspecialist trained healthcare workers and fulfill the clinical need for a nonsurgical treatment for chronic tympanic membrane perforation and CSOM.

A pilot study investigating basic fibroblast growth factor for the repair of chronic tympanic membrane perforations in pediatric patients

OBJECTIVE

A pilot study to investigate the utility of basic Fibroblast Growth Factor (bFGF) in tympanic membrane perforation (TMP) closure in a small cohort of pediatric patients.

METHODS

Prospective cohort study. Suitability for inclusion in the study was confirmed by the application of defined inclusion and exclusion criteria, and informed parental consent obtained. The technique used was a modification of the bFGF-technique by Kanemaru et al. Response to treatment was monitored with serial otoscopy and audiometric outcomes were determined. Statistical analysis of the outcomes was carried out.

RESULTS

TMPs were successfully closed in 7/12 children at the first attempt (58%) and in 10/12 children overall (83%). Hearing improvement was observed in 8/10 successfully treated cases (80%). There were no complications or adverse outcomes.

CONCLUSIONS

The topical bFGF regeneration technique offers a promising, minimally invasive alternative to conventional myringoplasty in pediatric patients with comparable success and reduced morbidity and cost, especially considering the option of performing repeat applications. Patients with an active infection or inflammation are not suitable for the bFGF-mediated technique.

Use of ambulatory anesthesia with manually assisted ventilation for tympanic membrane regeneration therapy in children

PURPOSE

To present the utility of ambulatory anesthesia using manually assisted ventilation via a facemask for tympanic membrane (TM) regeneration therapy in children.

MATERIAL AND METHODS

The study included 10 children (age 4-11years) in whom the duration of perforation before treatment exceeded 6months and who were followed for at least 1year after treatment between December 2009 and December 2012. Under ambulatory anesthesia using manually assisted ventilation via a facemask, TM regenerative therapy with atelocollagen combined with basic fibroblast growth factor was performed in children who could not tolerate the procedure under local anesthesia alone.

RESULTS

All of the children completed the TM regenerative therapy under ambulatory anesthesia in less than 5min. Complete closure was achieved in nine (81.8%) ears after 1year of postoperative follow-up.

CONCLUSION

TM regenerative therapy can be performed under local anesthesia in less than 5min without a skin incision. However, local anesthesia is often insufficient in small children undergoing this procedure. Therefore, ambulatory anesthesia using manually assisted ventilation via a facemask is appropriate to complete this procedure safely in small children.

Clinical study of transcanal closure of tympanic membrane perforations using a collagen sponge

Materials and methods:

We used an artificial dermis (Terdermis®), which is an atero-collagen sponge covered with a sheet of silicon.

Patients:

Nineteen ears of 17 patients with perforation of the tympanic membrane under various conditions, including large and wet perforations, underwent operation using this collagen sponge.

Results:

The success rate of closure after the initial surgery was 8/19. The overall success rate of closure after initial and re-operation was 14/19. The success rate of closure was 12/14 for small-sized perforations, 1/4 for middle-sized perforations and 1/1 for a large-sized perforation. Middle- and large-sized perforations required multiple surgeries. The success rate of closure was 11/11 for dry perforations, 3/4 for perforations with light otorrhoea and 0/4 for perforations with extensive otorrhoea.

Conclusion:

This surgery is a low-cost and minimally invasive surgery and has a high closure rate. This surgery is effective on small-sized, dry perforations although it can also close middle- and large-sized dry perforations.

Outlook for Tissue Engineering of the Tympanic Membrane

Tympanic membrane perforation is a common problem leading to hearing loss. Despite the autoregenerative activity of the eardrum, chronic perforations require surgery using different materials, from autologous tissue - fascia, cartilage, fat or perichondrium - to paper patch. However, both, surgical procedures (myringoplasty or tympanoplasty) and the materials employed, have a number of limitations. Therefore, the advances in this field are incorporating the principles of tissue engineering, which includes the use of scaffolds, biomolecules and cells. This discipline allows the development of new biocompatible materials that reproduce the structure and mechanical properties of the native tympanic membrane, while it seeks to implement new therapeutic approaches that can be performed in an outpatient setting. Moreover, the creation of an artificial tympanic membrane commercially available would reduce the duration of the surgery and costs. The present review analyzes the current treatment of tympanic perforations and examines the techniques of tissue engineering, either to develop bioartificial constructs, or for tympanic regeneration by using different scaffold materials, bioactive molecules and cells. Finally, it considers the aspects regarding the design of scaffolds, release of biomolecules and use of cells that must be taken into account in the tissue engineering of the eardrum. The possibility of developing new biomaterials, as well as constructs commercially available, makes tissue engineering a discipline with great potential, capable of overcoming the drawbacks of current surgical procedures.

Animal models of chronic tympanic membrane perforation: a 'time-out' to review evidence and standardize design

OBJECTIVE

To review the literature on techniques for creation of chronic tympanic membrane perforations (TMP) in animal models. Establishing such models in a laboratory setting will have value if they replicate many of the properties of the human clinical condition and can thus be used for investigation of novel grafting materials or other interventions.

METHODS

A literature search of the PubMed database (1950-August 2014) was performed. The search included all English-language literature published attempts on chronic or delayed TMP in animal models. Studies of non English-language or acute TMP were excluded.

RESULTS

Thirty-seven studies were identified. Various methods to create TMP in animals have been used including infolding technique, thermal injury, re-myringotomy, and topical agents including chemicals and growth factor receptor inhibitors. The most common type of animal utilized was chinchilla, followed by rat and guinea pig. Twenty three of the 37 studies reported success in achieving chronic TMP animal model while 14 studies solely delayed the healing of TMP. Numerous experimental limitations were identified including TMP patency duration of <8 weeks, lack of documentation of total number of animals attempted and absence of proof for chronicity with otoscopic and histologic evidence.

CONCLUSION

The existing literature demonstrates the need for an ideal chronic TMP animal model to allow the development of new treatments and evaluate the risk of their clinical application. Various identified techniques seem promising, however, a need was identified for standardization of experimental design and evidence to address multiple limitations.

Gelatin hydrogel with basic fibroblast growth factor for tympanic membrane regeneration

HYPOTHESIS

In this developmental research study that aimed to develop tympanic membrane regeneration therapy, we devised a method of sustained bFGF formulation release using gelatin hydrogel in a guinea pig eardrum perforation model.

BACKGROUND

Basic fibroblast growth factor (bFGF) can promote perforation closure. In addition, several studies of bFGF formulations have used gelatin hydrogel-bFGF coupled electrostatically to a gelatin polymer. BFGF is released gradually as a result of degradation of the gelatin polymer, and studies have shown that the long-term pharmacologic effects of bFGF can be maintained.

METHODS

Using a CO(2) laser, total tympanic membrane perforations were created in 24 guinea pig ears and divided into 3 groups: the bFGF-gelatin hydrogel group(n = 8), the saline-gelatin hydrogel group (n = 8), and the control group (n = 8). Either a bFGF formulation or saline was impregnated into gelatin hydrogen and implanted into the perforated tympanic membrane.

RESULTS

All ear drums of the control group showed large perforations at even the 30th postoperative day. The perforation persisted in 3 of 8 ears in the saline-gelatin hydrogel group, and the tympanic membranes that had achieved closure were thinned, whereas all ears in the bFGF-gelatin hydrogel group achieved closure of the perforation. In the ears in which a normal tympanic membrane had regenerated, histologic observation with hematoxylin and eosin staining revealed that, although mucosal and epithelial layer regeneration had occurred in the saline-gelatin hydrogel group, the bFGF-gelatin hydrogel group showed regeneration of the fibrous layer in addition to the other 2 layers.

CONCLUSION

These data suggest that hydrogel impregnated with bFGF induces regeneration of the tympanic membrane and can conservatively treat tympanic membrane perforation.

Regeneration of chronic tympanic membrane perforation using 3D collagen with topical umbilical cord serum

Chronic tympanic membrane (TM) perforation is one of the most common otology complications. Current surgical management of TM perforation includes myringoplasty and tympanoplasty. The purpose of this study was to evaluate the efficacy and feasibility of three dimensional (3D) porous collagen scaffolds with topically applied human umbilical cord serum (UCS) for the regeneration of chronic TM perforation in guinea pigs. To achieve this goal, we fabricated porous 3D collagen scaffolds (avg. strut diameter of 236 ± 51 μm, avg. pore size of 382 ± 67 μm, and a porosity of 96%) by using a 3 axis robot dispensing and low temperature plate systems. Guinea pigs were used in a model of chronic TM perforation. In the experimental group (n=10), 3D collagen scaffold was placed on the perforation and topically applied of UCS every other day for a period of 8 days. The control group ears (n=10) were treated with paper discs and phosphate buffered saline (PBS) only using the same regimen. Healing time, acoustic-mechanical properties, and morphological analysis were performed by otoendoscopy, auditory brainstem response (ABR), single-point laser Doppler vibrometer (LDV), optical coherence tomography (OCT), and light microscopic evaluation. The closure of the TM perforation was achieved in 100% of the experimental group vs. 43% of the control group, and this difference was statistically significant (p=0.034). The ABR threshold at all frequencies of the experimental group was significantly recovered to the normal level compared to the control group. TM vibration velocity in the experimental group recovered similar to the normal control level. The difference is very small and they are not statistically significant below 1 kHz (p=0.074). By OCT and light microscopic examination, regenerated TM of the experimental group showed thickened fibrous and mucosal layer. In contrast, the control group showed absence of fibrous layer like a dimeric TM.

Tissue engineering of the tympanic membrane

Tympanic membrane (TM) perforations are common, with current treatments for chronic perforations involving surgery, using various graft materials, from autologous cartilage or fascia through to paper patch. Recent research developments in this field have begun applying the principles of tissue engineering, with appropriate scaffolds, cells, and bioactive molecules (BMs). This has revolutionized the therapeutic approach due to the availability of a wide range of materials with appropriate compatibility and mechanical properties to regenerate the membrane acoustics and may also represent a paradigm shift in the management of TM perforations in an outpatient setting without surgery. However, many factors need to be considered in the fabrication of a bioengineered TM. This review discusses the issues associated with current treatment and examines TM wound healing relevant to the construction of a bioengineered TM. It also describes the tissue-engineering approach to TM regeneration by summarizing currently used scaffolds, BMs, and cells in TM wound healing. Finally, it considers the design of scaffolds, delivery of BMs, and cell engraftment toward potential clinical application.

Fibroblast colonization of modified silicone films

HYPOTHESIS

Development of silicone films with hydrophilic surface properties and with associated fibroblast colonization for tympanic membrane reconstruction.

BACKGROUND

Silicone films are used in ear surgery for splinting fresh eardrum perforations. The cure rate is high if the perforation is small and fresh. Persistent eardrum perforations have been treated in tympanoplasty procedures by splinting the tympanic membrane with silicone film. Silicone has hydrophobic properties and is poorly populated by cells.

METHODS

Silicone films with a thickness of 0.13 mm were treated in a low-pressure oxygen plasma for different times. Oxidation of the surface allowed hydroxyl groups to form. The altered surface properties of the film were measured using the method of contact angle against water. Treated and untreated films (d = 22 mm) were placed in 12-well culture plates with 50000 L929 fibroblasts and in a standard medium for different lengths incubated at 37 °C. The quantification of the vegetation was performed after 5 days using WST-1 Cell Proliferation Reagent. The resulting cell growth was visualized after different incubation times through the Live/Dead Assay by fluorescence microscopy and scanning electron microscopy.

RESULTS

The treatment of the films with low-pressure oxygen plasma resulted in a hydrophilic film surface. There were significant differences in fibroblast colonization in treated compared with untreated films. The hydrophilic silicone films had a higher quantity and quality of fibroblasts.

CONCLUSION

Further surface modifications could improve the film in respect of fibroblast vegetation. The effectiveness of the modified silicone sheets should be evaluated in vivo before clinical trials.

Healing of laser-induced tympanic membrane perforations in rats: no contribution of granulocyte colony-stimulating factor or Gelfoam

OBJECTIVES

To study whether granulocyte colony-stimulating factor together with Gelfoam (absorbable gelatin sponge, USP) could enhance the healing of freshly perforated tympanic membranes. The frequency and occurrence of different immunocompetent cells and collagen types was noted.

METHODS

Laser perforations were made in the tympanic membrane of rats that were sacrificed at different time intervals post-myringotomy: Day 1, 3, 6, and 12. Tympanic membrane specimens were embedded and sections were stained with hematoxylin/eosin and an immunohistochemical technique was used, with antibodies against macrophages, B-cells, T-cells, and type I-IV collagens. Semi-quantification was performed after counting positive cells, mean values were calculated and analyzed statistically.

RESULTS

All perforations, except one, had closed by Day 12 and no difference was observed between experimental and control ears at the other time points. Gelfoam was still present in a high amount at Day 12. The sections were initially stained positive for type I and II collagen, but after Day 6, the regenerating tissue stained positive for mainly type III and IV collagens. Results showed that the recruitment of macrophages, B-cells, and T-cells could not be mapped with a statistical significance.

CONCLUSIONS

This study showed that at 6-12 days post-laser myringotomy, type III and IV collagen has replaced the collagen type II that normally constitutes the healthy tympanic membrane. There is a concern for excessive scarring involving adjacent structures. It was also seen that the combination of Gelfoam and granulocyte colony-stimulating factor or saline did not affect the healing times in perforated tympanic membranes. No significant results regarding the inflammatory cell recruitment could be obtained on the studied time points or between experimental and control ears, except for in the Gelfoam matrix.

Analysis of the effectiveness of basic fibroblast growth factor treatment on traumatic perforation of the tympanic membrane at different time points

OBJECTIVE

The aim of this study was to evaluate the effectiveness of basic fibroblast growth factor (bFGF) treatment on traumatic perforation of the tympanic membrane at different time points.

RESEARCH DESIGN

This is a prospective clinical study.

METHODS

Patients with traumatic perforations of the tympanic membrane were given a treatment of gelatin sponge + bFGF at different time intervals of 3 days, 4 to 7 days, 8 to 15 days, and more than 4 weeks after the injury. Healing rate and time of perforation were also observed after 1 month.

RESULTS

In 147 ears, 144 (98.0%) were healed. The perforation healing rates were 98.6%, 97.6%, 96.3%, and 100%, respectively, at the following time intervals: within 3 days, 4 to 7 days, 8 to 14 days, and 2 to 4 weeks since the injury. This was quite true without any significant difference (P > .05). Meanwhile, in the small perforation healing of 120 ears, the average healing times from admission to perforation within 3 days, 4 to 7 days, and 8 to 14 days after the injury were 7.95 ± 2.07, 6.75 ± 2.67, and 4.18 ± 0.91 days, respectively. No significant difference was found among the 3 groups (P(1) < .01).

CONCLUSION

Treating traumatic perforation of the tympanic membrane using the bFGF technique at different times of admissions is quite effective.

Regenerative treatment for tympanic membrane perforation

OBJECTIVE

To establish a tissue engineering therapy for the treatment of large tympanic membrane perforation (TMP) without the need for conventional surgical therapy.

STUDY DESIGN

Randomized control trial.

SETTING

General hospital.

PATIENTS AND METHODS

A total of 63 chronic TMPs were randomly selected from outpatients.

INTERVENTION

Of the total 63 chronic TMPs, 53 were randomly assigned to the basic fibroblast growth factor (b-FGF) group and the remaining 10 were randomly assigned to the control group. Materials used for the TM repair were gelatin sponge and fibrin glue with/without b-FGF. After creating a mechanical disruption of the edge of the TMP, a gelatin sponge was immersed in b-FGF or saline (for the control group) and placed over the perforation. Fibrin glue was dripped over the sponge as a sealant.

MAIN OUTCOME MEASURES

The effectiveness of this therapy was evaluated by closure rates, hearing level, and sequelae 3 weeks after treatment. The treatment was repeated up to 4 times for cases in which complete closure of the TMP was not achieved after 1 round of treatment.

RESULTS

Complete closure of the TMP was achieved in more than 98.1% (52/53) of the patients in the b-FGF group and 10% (1/10) of the patients in the control group. The average hearing level of all patients with successful TM repair was improved. Serious sequelae were not observed in any patient.

CONCLUSION

This study demonstrates that a combination of gelatin sponge, b-FGF, and fibrin glue enables the regeneration of the TM without conventional operative procedures. This innovative regenerative therapy is an easy, safe, cost-effective, and minimally invasive outpatient treatment.

Outcome of children with edge-everted traumatic tympanic membrane perforations following spontaneous healing versus fibroblast growth factor-containing gelfoam patching with or without edge repair

OBJECTIVES

To retrospectively analyze the outcome of children with edge-everted tympanic membrane (TM) perforations following spontaneous healing and fibroblast growth factor-containing gelfoam patching with or without repair of the edge flaps.

METHODS

Medical records of children with TM perforations who underwent spontaneous healing (n = 69) or received fibroblast growth factor (FGF)-containing gelfoam patching treatment (n = 67) were retrieved from the Records Department of the Wenzhou Medical College-Affiliated Yiwu Hospital in China. The demographic data and outcome measures were analyzed and compared between these two groups of patients.

RESULTS

Patching with FGF-containing gelfoams significantly improved the healing rate (P < 0.01) and the average perforation closure time (P<0.01), as compared with spontaneous healing. Repair of the perforation edge flaps did not significantly affect the outcome of gelfoam patching (P>0.05), despite a slightly reduced healing rate (96.4% versus 100%) and a slightly shorter closure time (10.2 ± 2.6 d versus 10.9 ± 3.3 d) observed as compared with no edge repair. The everted perforation edge flaps formed scabs during the process of spontaneous healing whereas they underwent retraction and eventually dissolved during the process of gelfoam patching-facilitated healing.

CONCLUSIONS

As compared with spontaneous healing, FGF-containing gelfoam patching had an improved outcome in children with edge-everted traumatic eardrum perforation. Repair of everted edge flaps did not affect the healing outcome. Our results suggest that growth factor-containing gelfoam patching without eardrum flap repair would offer a feasible option to manage traumatic tympanic membrane perforations in children.

Basic fibroblast growth factor combined with atelocollagen for closing chronic tympanic membrane perforations in 87 patients

OBJECTIVE

To present the clinical results of closing chronic tympanic membrane (TM) perforations using basic fibroblast growth factor (bFGF) combined with an atelocollagen/silicone bilayer membrane patch.

STUDY DESIGN

Closure of TM perforations in 87 patients was attempted using bFGF, which is thought to promote the regeneration of TM tissues by facilitating the growth of fibroblasts and collagen fibers.

METHODS

Under an operating microscope, the margin of the perforation was trimmed, and a piece of an atelocollagen/silicone bilayer membrane was placed in the perforation with the silicon layer facing outward and then infiltrated with 0.1 ml of trafermin. Data obtained from patient records included patient age, perforation size, and duration of treatment, with a focus on hearing improvement and complete TM closure.

RESULTS

The mean perforation size before treatment was 14.4%. Complete closure of the TM perforation was achieved in 80 patients (92.0%), whereas pinholes remained in 5 patients (8.7%), and small perforations were observed in 2 patients (2.3%). In the patients with complete closure, the TM perforations closed after an average 1.8 treatments, and hearing improved by 13.6 dB.

CONCLUSION

This study demonstrated that bFGF combined with atelocollagen is effective for the conservative treatment of TM perforation.

Regeneration of aged vocal fold: first human case treated with fibroblast growth factor

BACKGROUND/OBJECTIVES

Aged vocal folds are characterized by atrophy of the mucosa, which causes dysphonia and is difficult to treat. We have revealed a therapeutic potential of basic fibroblast growth factor (bFGF) for tissue regeneration of the aged vocal fold. We report here the first human case that has been treated with bFGF.

STUDY DESIGN

Institutional review board approved clinical human trial.

METHODS

A 63-year-old man with atrophied vocal folds was treated by local injection of 10 muicrog of bFGF into the left vocal fold under topical anesthesia. The effects of the injection were examined after 1 to 3 months by videostroboscopy, acoustic and aerodynamic measurements.

RESULTS

The atrophy of the vocal fold was improved at 1 week after the injection and glottic gap disappeared. Aerodynamic and acoustic parameters also showed remarkable improvement. These positive effects were maintained up to 3 months.

CONCLUSION

The first case with aged vocal folds treated with bFGF administration is presented. The results are encouraging, suggesting therapeutic effects of bFGF for atrophied vocal folds in human.

[Tympanic membrane perforation and tympanoplasty]

OBJECTIVES

To report anatomic and physiologic characteristics of the tympanic membrane, to discuss the etiology and pathogenesis of tympanic perforation, and to discuss its management.

MATERIAL AND METHODS

After a review of the literature, different surgical techniques and the postoperative results were evaluated.

RESULTS

The rate of tympanic membrane closure is greater than 90% for the majority of authors. Age, mucosa inflammation, pathological contralateral ear (perforation, otitis media, cholesteatoma), and surgical experience influence this result.

DISCUSSION

Even if surgical results are good, abstention must always be proposed and all complications must be explained.

CONCLUSION

Palisade cartilage tympanoplasty is an effective technique for both tympanic membrane closures.

Influence of topical application of basic fibroblast growth factor upon inner ear

BACKGROUND

Basic fibroblast growth factor (b-FGF) has recently been shown to have a positive effect on the treatment of postoperative mastoid cavity problem, but its ototoxicity has not been investigated.

OBJECTIVE

To investigate the effect of b-FGF on the inner ear of guinea pigs.

STUDY DESIGN AND SETTING

In groups A (n = 10) and B (n =11), b-FGF was applied into the left external auditory canal and the middle ear, respectively. The right ear served as a control. At 1 week after b-FGF administration, the endocochlear DC potential (EP) was measured, and morphology of the cochleae was examined by scanning electron microscopy.

RESULTS

In group A, the EP values of experimental ears and controls were 90.0 +/- 8.4 (mV, mean +/- SD) and 89.4 +/- 4.3 (P > 0.05). In group B, the values were 86.5 +/- 11.4 and 87.5 +/- 6.1, respectively, (P > 0.05). Morphological findings showed no damage on the cochlear.

CONCLUSION

Application of b-FGF to the external and middle ears does not seem to have an apparent risk of ototoxicity.

Behandlung von Trommelfellperforationen mit Fibringel

BACKGROUND

The goal of this study was to evaluate the effects of a fibrin gel on the healing of tympanic membrane perforation in rats.

METHODS

Prolonged tympanic membrane perforations in 12 rats were created by application of mitomycin C to the intact tympanic membranes followed by bilateral myringotomy. Repeated applications of a fibrin gel to the perforation site of one tympanic membrane were performed in each animal. Tympanic membranes were observed for a total of 8 weeks.

RESULTS

One perforation in each group was already patent at the end of the observation period. The mean healing period of the remaining tympanic membranes was found to be 16.7 days in the fibrin gel group and 19.6 days in the control group.

CONCLUSION

A fibrin sheet does not seem to promote the wound healing process of tympanic membranes. However, the sheet might serve as a drug-delivery system for growth factors in the treatment of tympanic membrane perforations, because of its biocompatibility.

A basic fibroblast growth factor improved the quality of skin grafting in burn patients

To avoid hypertrophic scars in burn wounds, the simultaneous application of basic fibroblast growth factor (bFGF) with regular surgical debridement and skin grafting was investigated for skin hardness by clinical examination and instrumental measurement. As little is known about the role of bFGF in wounds, burn wound scars were tested for hardness. Burn scars in various anatomical locations at least 1 year after final wound healing clinically demonstrated a significantly lower hard score in bFGF-treated wounds than in non-bFGF wounds (0.95+/-0.51 versus 2.3+/-0.66, respectively, p<0.01). In addition, a durometer, which is widely used in industry to measure materials similar to skin, such as rubber and thread-balls, demonstrated a significantly lower reading in bFGF-treated wounds than in non-bFGF wounds (7.9+/-3.64 versus 15.5+/-4.39, bFGF versus non-bFGF, respectively, p<0.01). The results demonstrated that burn wounds treated with clinically approved bFGF might contribute to a better cutaneous wound quality, at least in terms of hardness.

Inlay butterfly cartilage tympanoplasty in children

OBJECTIVE

To assess the results of inlay butterfly cartilage tympanoplasty in children.

STUDY DESIGN

Before-and-after trial; follow-up duration, 26.6 +/- 19.9 months (mean +/- standard deviation).

SETTING

Tertiary referral center.

PATIENTS

Fifty-nine pediatric cases of tympanic membrane perforation.

INTERVENTION

Inlay butterfly cartilage tympanoplasty was performed under general anesthesia according to the technique originally described by Eavey and modified by Lubianca-Neto (i.e., without any associated split-thickness skin graft).

MAIN OUTCOME MEASURES

Percentage of perforation closures, surgical complications, preoperative and postoperative puretone hearing thresholds; the results of inlay butterfly cartilage tympanoplasty were compared with those obtained in a retrospective series of 29 underlay fascia temporalis myringoplasties.

RESULTS

The 71% "take rate" of inlay butterfly cartilage tympanoplasty was not significantly different from the 83% take rate obtained with underlay fascia temporalis tympanoplasty (p = 0.23, chi test). The anatomic results were improved when the graft diameter was at least 2 mm larger than the size of the perforation (81% take rate) (p = 0.009, chi test). No iatrogenic cholesteatoma was observed. Pure-tone hearing thresholds were improved at 0.5, 1, and 2 kHz, and stable at 4 kHz. Hearing levels were not different from those obtained with underlay fascia temporalis tympanoplasty.

CONCLUSION

Inlay butterfly cartilage tympanoplasty is a safe, efficient, time-saving, and easy technique of tympanoplasty in children. Anatomic results may be improved by associating a split-thickness skin graft and/or by trimming a tragal graft much larger than the size of the perforation.

Traumatische Trommelfellperforationen

BACKGROUND

The aim of this study was to evaluate the effects of an alginate matrix releasing epidermal growth factor on healing after acute tympanic membrane perforation in rats.

METHOD

A total of 20 male rats were divided into two groups. In each animal, a randomly chosen tympanic membrane was perforated by heat. A piece of alginate matrix (control group) or alginate matrix loaded with 0.25 microg epidermal growth factor (EGF group) was then placed on the perforation. The rat ears were examined after days 3, 6, 9, and 14 and every week thereafter for a total of 11 weeks. Each matrix was removed on day 9. To examine the status of the tympanic membranes on day 14, one randomly chosen membrane from each group was histopathologically examined.

RESULTS

By day 6, complete closure of the tympanic membrane perforation was achieved in 56% of the EGF group, whereas it was achieved in only 10% in the control group. By day 14, all tympanic membrane perforations were closed in both groups. There were no complications and no significant differences in the histopathologic parameters between the EGF group and the control group.

CONCLUSION

An alginate matrix seems to be a useful EGF-delivery system to the tympanic membrane.

Repair of intractable cerebrospinal fluid rhinorrhea with mucosal flaps and recombinant human basic fibroblast growth factor: technical case report

OBJECTIVE AND IMPORTANCE

Repair of a cerebrospinal fluid leak is not always easy, especially when a large fistula, with concomitant infection and injured mucosa, has developed from repeated transsphenoidal operations. We repaired such a sellar floor defect with mucosal flaps via the endonasal endoscopic approach and finally obliterated the fistula by promoting granulation-like tissue formation with recombinant human basic fibroblast growth factor (bFGF).

CLINICAL PRESENTATION

A 27-year-old woman with intractable cerebrospinal fluid rhinorrhea was referred to our department after repeated operations for a relapsing Rathke's cleft cyst. Endonasal endoscopic examination revealed a large bone defect on the sellar floor through which previously packed fat and fascia were exposed to the nasal cavity.

INTERVENTION

Mucosal flaps were harvested endoscopically from the nasal septum and the superior and middle turbinates. These pedicled flaps were transposed to the sellar defect. The flaps survived but did not cover the whole area, resulting in gaps between the flaps through which cerebrospinal fluid still leaked. Recombinant bFGF was repeatedly applied endoscopically to the mucosal flaps. The flaps turned into granulation-like tissue, and complete mucosal covering was finally achieved.

CONCLUSION

bFGF has a wide range of biological effects, including stimulation of fibroblast growth and promotion of angiogenesis. It accelerates wound healing and is used clinically to treat dermal ulcers. The method presented here to treat an intractable fistula with mucosal flap and recombinant bFGF may suggest a new clinical application of bFGF. This possibility should be examined in a large number of patients in the future.