Healing large tympanic membrane perforations using hyaluronic acid, basic fibroblast growth factor, and epidermal growth factor

Tissue engineering in otology: a review of achievements

Tissue engineering application in otology spans a distance from the pinna to auditory nerve covered with specialized tissues and functions such as sense of hearing and aesthetics. It holds the potential to address the barriers of lack of donor tissue, poor tissue match, and transplant rejection through provision of new and healthy tissues similar to the host and possesses the capacity to renew, to regenerate, and to repair in-vivo and was shown to be a bypasses for any need to immunosuppression. This review aims to investigate the application of tissue engineering in otology and to evaluate the achievements and challenges in external, middle and inner ear sections. Since gaining the recent knowledge and training on use of different scaffolds is essential for otology specialists and who look for the recovery of ear function and aesthetics of patients, it is shown in this review how utilizing tissue engineering and cell transplantation, regenerative medicine can provide advancements in hearing and ear aesthetics to fit different patients' needs.

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.

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.

Full-thickness cartilage graft myringoplasty combined with topical application of bFGF for repair of perforations with extensive epithelialization

OBJECTIVE

The objective of this study is to evaluate the long term outcome of endoscope full-thickness cartilage graft myringoplasty combined with topical application of basic fibroblast growth factor (bFGF) for repair of perforations with extensive epithelialization.

MATERIALS AND METHODS

In total, 65 perforations with extensive epithelialization of edges were divided into the endoscope full-thickness cartilage graft myringoplasty with (bFGF treatment group) and without topical application of bFGF (control group) groups. The outcomes were evaluated in terms of the hearing gain and graft success rate at 12 and 24 months post-surgery.

RESULTS

All patients were followed up at 24 months. Graft success rate was 97.2% in postoperative 12th month and 97.2% in postoperative 24th month in the bFGF group, whereas graft success rate was 100.0% in postoperative 12th month and 86.2% in postoperative 24th month in the control group. The re-perforation wasn't evident in any patients in the bFGF group while re-perforation in 4 (13.8%) patients in the control group, with statistical significance (P = 0.023).Comparing the two groups, there was no difference regardless of in preoperative or postoperative 12 months mean ABG or ABG closure. CT images revealed the well pneumatized middle ear and mastoid cells at postoperative 24th months in both groups, no middle ear cholesteatoma and keratin pearls were found during the period of follow up.

CONCLUSIONS

The cartilage-perichondrium double graft combined with bFGF are a feasible and effective method for providing the long-term graft success rate of the perforations with extensive epithelialization.

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.

Comparative study of epidermal growth factor and observation only on human subacute tympanic membrane perforation

OBJECTIVE

To compare the effects of epidermal growth factor (EGF) and observation only on human subacute tympanic membrane perforation (TMP).

METHODS

A total of 44 patients with traumatic TMPs >2 months after trauma were divided into an observation group (n = 18) and EGF group (n = 26). Patients in the EGF group underwent direct application of EGF without stripping of the perforation edge. All patients were followed up for at least 6 months. The TMP closure rate, closure time, and hearing gain were evaluated.

RESULTS

At 6 months, 25 of 26 (96.2%) perforations achieved complete closure with a mean closure time of 9.1 ± 3.9 days (range, 3-14 days) in the EGF group. However, only 11 of 18 (61.1%) perforations achieved complete closure in the observation group, with a mean closure time of 20.6 ± 10.7 days (range = 9-71 days). The patients in the EGF-treated group had significantly improved closure rates (P = 0.026) and a reduced closure time (P < 0.01) compared to those in the observation group. The difference in mean hearing improvement between the two groups was not statistically significant (P = 0.86).

CONCLUSIONS

Topical application of EGF improved the closure rate and shortened the closure time of human subacute TMPs compared with spontaneous healing, the stripping of the perforation edge was unnecessary. This treatment is simple and convenient and should be recommended pre-myringoplasty.

The short- and long-term adverse effects of FGF-2 on tympanic membrane perforations

SUMMARY

The objective of this study was to investigate the short- and long-term adverse effects of fibroblast growth factor-2 treatment of tympanic membrane perforations. A total of 134 patients with traumatic tympanic membrane perforations were randomly divided into two groups: an observational group and a fibroblast growth factor-2 treatment group. The closure rate, closure time and principal side-effects were compared between the groups at 6 and 12 months. At 6 months, 131 patients were examined to determine healing outcomes and short-term side-effects. The total closure rate differed significantly between the fibroblast growth factor-2 and observational groups (95.5% vs 73.4, p #x003C; 0.01). The fibroblast growth factor-treated group exhibited a significantly shorter closure time than the observational group (11.9±3.1 days vs 52.6 ± 18.1 days, p = 0.00). Three patients with secondary otitis media with effusion, and three with reperforations, were noted in the fibroblast growth factor-2 group. We additionally performed long-term follow-up on 89.1% of the patients in the observational group and 92.5% of the patients in the fibroblast growth factor-2 group; follow-up was performed 16-42 months after perforation closure. Only a small perforation of the pars flaccida developed in the fibroblast growth factor-2 group. No middle ear cholesteatoma was noted in either group. This study suggests that the topical application of fibroblast growth factor-2 to human traumatic tympanic membranes is safe. Otorrhoea was the most common short-term side-effect; other less common side-effects included otitis media with effusion and reperforation. No serious long-term side-effects were found.

Bacterial cellulose graft versus fat graft in closure of tympanic membrane perforation

OBJECT

To compare between results of bacterial cellulose graft myringoplasty and fat graft myingoplasty in patients had mild or moderate size safe perforation.

METHODS

120 patients undergoing myringoplasty due to mild or moderate size perforation were divided into 3 groups: group I: 40 patients undergoing myringoplasty with use of bacterial cellulose graft, group II: 40 patients undergoing myringoplasty with use of fat graft, group III: 40 patients undergoing usual myringoplasty with use of temporalis fascia graft (control group).

RESULTS

Healing in 20 patients with small perforation and 17 patients with moderate perforation in Group I, Healing in 15 patients with small perforation and 10 patients with moderate perforation in Group II, Healing in 18 patients with small perforation and 12 patients with moderate perforation in Group III.

CONCLUSION

Bacterial cellulose graft myringoplasty would be a good, simple, rapid and safe surgery that could be done under local anesthesia in outpatient clinic with shorter time of surgery than fat graft myringoplasty and temporalis fascia graft myringoplasty, with better hearing and healing.

SUMMARY AT GLANCE

120 patients undergoing myringoplasty were divided into 3 groups to compare between results of bacterial cellulose graft myringoplasty, fat graft myringoplasty and temporalis fascia graft myringoplasty.

Biological therapies in otology

Hearing loss is present in millions of people worldwide. Current treatment for patients with severe to profound hearing loss consists of cochlear implantation. Providing the cochlear nerve is intact, patients generally benefit greatly from this intervention, frequently achieving significant improvements in speech comprehension. There are, however, some cases where current technology does not provide patients with adequate benefit. Ongoing research in cell transplantation and gene therapy promises to lead to new developments that will improve the function of cochlear implants. Translation of these experimental approaches is presently at an early stage. This review focuses on the application of biological therapies in severe hearing loss and discusses some of the barriers to translating basic scientific research into clinical reality. We emphasize the application of these novel therapies to cochlear implantation.

Pretreatment factors affecting traumatic tympanic membrane regeneration therapy using epidermal growth factor

OBJECTIVE

The use of epidermal growth factor (EGF) to achieve closure of human traumatic tympanic membrane perforations (TMPs) was recently reported. However, pretreatment factors affecting healing outcomes have seldom been discussed. This study was performed to evaluate pretreatment factors contributing to the success or failure of TMP healing using EGF.

DESIGN AND PARTICIPANTS

This was a retrospective cohort study of 95 TMPs who were observed for at least 6 months after EGF treatment. Eleven factors considered likely to affect healing outcome were evaluated by univariate and multivariate logistic regression analyses.

INTERVENTIONS

Each traumatic TMP was treated by daily topical application of EGF. The main outcome measures were complete closure versus failure to close and mean closure time.

RESULTS

A total of 95 patients were included in the analyses. The total closure rate was 92.6% at 6 months, and the mean closure time was 10.5 ± 4.8 days. The closure rate was not significantly different according to the duration of perforation ≤3 days and >3 days (P = 0.816). However, the mean closure time was significantly different according to the duration of perforation (P < 0.001). The perforation size did not affect the closure rate (P = 0.442). The mean closure time in the low-dose EGF group was significantly shorter than that in the high-dose EGF group (P = 0.001). Logistic regression analyses showed that perforations with preexisting myringosclerosis were more likely to fail to close compared to those without preexisting myringosclerosis (P = 0.001). Multivariate logistic regression analyses showed that the duration of perforation (P = 0.011), size of perforation (P < 0.001), and involvement of the malleus in perforation (P = 0.005) were factors independently correlated with closure time.

CONCLUSIONS

Daily application of EGF can be used to treat all traumatic TMPs. The size of the perforation and inverted edges did not affect the closure rate, and the most beneficial dosage was sufficient to keep the eardrum moist. Multivariate logistic regression analyses revealed a significant correlation between preexisting myringosclerosis and failure to heal. Nevertheless, the size of perforation, starting time of application, and malleus injury were independent prognostic factors for prolonged healing time.

Efficacy of EGF and Gelatin Sponge for Traumatic Tympanic Membrane Perforations: A Randomized Controlled Study

OBJECTIVE

To compare the outcomes of epidermal growth factor (EGF) and gelatin sponge patch treatments for traumatic tympanic membrane perforations.

STUDY DESIGN

Prospective, randomized, controlled.

SETTING

University-affiliated teaching hospital.

SUBJECTS AND METHODS

In total, 141 perforations encompassing >50% of the eardrum were randomly divided into 3 groups: EGF (n = 47), gelatin sponge patch (n = 47), and observation (n = 47). The edges of the perforations were not approximated. The closure rate, mean closure time, and infection rate were evaluated at 6 months and the related factors analyzed.

RESULTS

A total of 135 perforations were analyzed. At 6 months, the closure rates were 97.8%, 86.7%, and 82.2% in the EGF, gelatin sponge patch, and spontaneous healing groups, respectively (P = .054). The mean ± SD closure time was 11.12 ± 4.60, 13.67 ± 5.37, and 25.65 ± 13.32 days in the EGF, gelatin sponge patch, and spontaneous healing groups, respectively (P < .001). In addition, the presence of infection was not significantly associated with rate of closure in any group.

CONCLUSIONS

As compared with spontaneous healing, daily application of EGF and gelatin sponge patching reduced the closure time of traumatic tympanic membrane perforations. EGF treatment had a higher closure rate and shorter closure time but resulted in otorrhea. By contrast, gelatin sponge patches did not improve the closure rate or cause otorrhea but required repeated patch removal and reapplication. Thus, the appropriate treatment should be selected according to patient need.

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.

Chitosan/PEI patch releasing EGF and the EGFR gene for the regeneration of the tympanic membrane after perforation

EGF and EGFR gene-releasing PEI/chitosan patch (EErP-CPs) was developed to increase the regeneration of tympanic membrane perforations.

A comparative study to evaluate the efficacy of EGF, FGF-2, and 0.3% (w/v) ofloxacin drops on eardrum regeneration

BACKGROUND

Traumatic tympanic membrane perforations (TMPs) tend to spontaneous healing, however, large TMPs usually fail to healing. Clinical and experimental studies had demonstrated that growth factors accelerated the healing of large TMPs. The aim of this study was to compare the effects of growth factors and 0.3% (w/v) ofloxacin drops n the healing of human large TMPs.

METHODS

A total of 184 human large traumatic TMPs were randomly assigned to receive epidermal growth factor (EGF) treatment, fibroblast growth factor-2 (FGF-2) treatment, 0.3% (w/v) ofloxacin drops treatment, and conservative observation (only).

RESULTS

A total of 180 patients were analyzed in this study at the 6-month follow-up. The closure rates of the perforations in the EGF, FGF-2, 0.3% (w/v) ofloxacin drops, and conservative observation groups were 91.11%, 93.18%, 95.65%, and 82.22%, respectively, the closure rates did not significantly differ among the groups (P = .165). Similarly, pairwise comparisons did not reveal any significant between-group differences (P > .0083). However, the difference of the mean closure time was significant among the 4 groups (P < .001), pairwise comparisons showed that closure time was significantly longer in the observational group than in the other 3 groups (P < .001). Nevertheless, no significant difference in mean closure time was evident between any 2 treated groups (P > .0083). The mean hearing gain after 6 months was 11.49 ± 5.88 dB for the EGF group, 10.89 ± 5.16 dB for the FGF-2 group, 10.54 ± 5.56 dB for the ofloxacin group, and 9.29 ± 5.36 dB for the observation group. Differences in hearing improvement rates among the 4 groups were not statistically significant (P = .283).

CONCLUSION

Epidermal growth factor, FGF-2, and 0.3% (w/v) ofloxacin drops accelerated the closure of large TMPs compared with conservative treatment. Surprisingly, neither the closure rate nor closure time differed significantly among the 3 treated groups. Further experimental studies to demonstrate whether 0.3% (w/v) ofloxacin per se accelerates the healing of TMPs will be interesting in the future.

A moist edge environment aids the regeneration of traumatic tympanic membrane perforations

OBJECTIVE

To review the history of moist therapy used to regenerate traumatic tympanic membrane perforations.

STUDY DESIGN

Literature review.

METHODS

The literature on topical agents used to treat traumatic tympanic membrane perforations was reviewed, and the advantages and disadvantages of moist therapy were analysed.

RESULTS

A total of 76 studies were included in the analysis. Topical applications of certain agents (e.g. growth factors, Ofloxacin Otic Solution, and insulin solutions) to the moist edges of traumatic tympanic membrane perforations shortened closure times and improved closure rates.

CONCLUSION

Dry tympanic membrane perforation edges may be associated with crust formation and centrifugal migration, delaying perforation closure. On the contrary, moist edges inhibit necrosis at the perforation margins, stimulate proliferation of granulation tissue and aid eardrum healing. Thus, moist perforation margins upon topical application of solutions of appropriate agents aid the regeneration of traumatic tympanic membrane perforations.

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.

[Biological therapies in otology. German version]

Millions of people worldwide suffer from hearing loss. Current treatment for patients with severe to profound hearing loss consists of cochlear implants. Providing the cochlear nerve is intact, patients generally benefit enormously from this intervention, frequently achieving significant improvements in speech comprehension. There are, however, some cases where current technology does not provide patients with adequate benefit. New therapeutic concepts based on cell transplantation and gene therapy are developing rapidly, at least in the research sector. Compared to the wealth of basic research available in this area, translation of these new experimental approaches into clinical application is presently at a very early stage. The current review focuses on translatable treatment concepts and discusses the barriers that need to be overcome in order to translate basic scientific research into clinical reality. Furthermore, the first examples of clinical application of biological therapies in severe hearing loss are presented, particularly in connection with cochlear implants.

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.

The effect of ofloxacin otic drops on the regeneration of human traumatic tympanic membrane perforations

OBJECTIVE

To investigate the effects of direct application of ofloxacin otic drops on human traumatic tympanic membrane perforations (TMPs).

STUDY DESIGN

Prospective, sequential allocation, controlled clinical study.

SETTING

Tertiary university hospital.

PARTICIPANTS

In total, 149 patients with traumatic TMPs were recruited. They were allocated sequentially to two groups: a conservative observation group (n = 75) and a ofloxacin drops-treated group (n = 74).

MAIN OUTCOME MEASURES

The closure rate, closure time and rate of otorrhoea were compared between the groups at 6 months.

RESULTS

In total, 145 patients were analysed. The closure rates of medium perforations between the groups were not significantly different (P = 0.35); however, the ofloxacin drops-treated group had a significantly shorter closure time for medium perforations than the observation group (P < 0.01). Additionally, the ofloxacin drops-treated group showed improvement in the closure rate of large perforations (P = 0.02) and a significantly shorter mean closure time (P < 0.01) than the observation group. However, purulent otorrhoea was not significantly different between the groups (P = 0.37).

CONCLUSIONS

The present findings indicate that the moist eardrum environment resulting from topical application of ofloxacin drops shortened the closure time and improved the closure rate, but did not affect hearing improvement or increase the rate of middle ear infection of large traumatic TMPs. Thus, although traumatic TMPs tend to heal spontaneously, moist therapy can be considered for traumatic, large TMPs in the clinic.

Comparative study on the effects of EGF and bFGF on the healing of human large traumatic perforations of the tympanic membrane

OBJECTIVES/HYPOTHESIS

We evaluated the effects of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) on the healing of large traumatic tympanic membrane perforations (TMPs).

STUDY DESIGN

Prospective clinical study.

SETTING

Tertiary university hospital.

METHODS

A randomized, prospective analysis was performed between June 2013 and August 2014 on the treatment of traumatic TMPs larger than 25% of the TM. Closure rate, closure time, hearing gain, and rate of otorrhea were compared between EGF and bFGF groups, as well as to an observation-only group.

RESULTS

Final analysis was performed on 86 patients at 3 months. The closure rates of perforation in the EGF, bFGF, and observation groups were 86.2%, 89.3%, and 72.4%, respectively. The closure rates in the EGF and bFGF groups were 14% to 17% higher than in the observation group, although the difference was not statistically significant for the total closure rate among the three groups (P = 0.200). The average closure time was significantly longer (P < 0.01) in the observation group than in the EGF and bFGF groups. However, the closure times in the EGF and bFGF groups were not significantly different (P = 0.92). In addition, differences in purulent otorrhea rates among the groups were not statistically significant (P = 0.82).

CONCLUSIONS

Both EGF and bFGF can accelerate the closure of human large traumatic TMPs. The healing outcomes among the two growth factors were not significantly different.

Latent progenitor cells as potential regulators for tympanic membrane regeneration

Tympanic membrane (TM) perforation, in particular chronic otitis media, is one of the most common clinical problems in the world and can present with sensorineural healing loss. Here, we explored an approach for TM regeneration where the latent progenitor or stem cells within TM epithelial layers may play an important regulatory role. We showed that potential TM stem cells present highly positive staining for epithelial stem cell markers in all areas of normal TM tissue. Additionally, they are present at high levels in perforated TMs, especially in proximity to the holes, regardless of acute or chronic status, suggesting that TM stem cells may be a potential factor for TM regeneration. Our study suggests that latent TM stem cells could be potential regulators of regeneration, which provides a new insight into this clinically important process and a potential target for new therapies for chronic otitis media and other eardrum injuries.

Evaluation of the optimum time for direct application of fibroblast growth factor to human traumatic tympanic membrane perforations

OBJECTIVE

The aim of this study was to determine the optimum time for direct application of basic fibroblast growth factor (bFGF) on large traumatic tympanic membrane perforations (TMPs).

STUDY DESIGN

Prospective clinical study.

SETTING

Tertiary University Hospital.

METHODS

Ninety-three patients, with traumatic TMPs greater in extent than 25% of the entire tympanic membrane, were randomized into observation and bFGF-treated groups (~0.2-0.25 mL of bFGF solution was applied directly onto the TM once daily and continued until the perforation closed). Initial visit times were subcategorized into perforation durations of ≤3 and >3 days, thereby rendering two subgroups, as follows: A and B in the observation group; and C and D in the bFGF-treated group. The closure rate and mean closure time were evaluated after 6 months.

RESULTS

Eighty-six patients were finally analyzed. After 6 months, the bFGF-treated group exhibited a significantly higher total closure rate (97.8 versus 82.5%, p < 0.05) and a shorter mean closure time (12.5 ± 3.4 versus 34.0 ± 5.9 days, p < 0.05) compared with the spontaneous healing group. In addition, in the observation group, visiting time was not associated with differences in closure rate (p > 0.05) and mean closure time (p > 0.05), between the A and B subgroups. Similarly, in the bFGF-treated group, visiting time was not associated with differences in closure rate (p > 0.05) between the C and D subgroups. However, the D subgroup was characterized by significantly shortened mean closure time compared with the C subgroup (p < 0.05).

CONCLUSIONS

This study shows the beneficial effect of bFGF on human traumatic large TMPs when applied after the 3rd day post-injury had passed (i.e. during the proliferative stage of wound healing). The procedure can not only significantly shorten closure time but can also reduce both the clinical administration duration and occurrence of side-effects associated with bFGF.

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.

Regeneration of chronic tympanic membrane perforation using an EGF-releasing chitosan patch

Most chronic tympanic membrane (TM) perforations require surgical interventions such as tympanoplasty because, unlike with acute perforations, it is very difficult for the perforations to heal spontaneously. The purpose of this study was to develop novel therapeutic techniques and scaffolds that release growth factors to treat chronic TM perforations. We evaluated the cell proliferation effects of the epidermal growth factor (EGF) and fibroblast growth factor (FGF) on in vitro cultures of TM cells using an MTT assay. They both showed similar efficacy, so we used EGF because of its lower cost. We then constructed an EGF-releasing chitosan patch scaffold (EGF-CPS) based on previous studies. We analyzed its toxicity and strength, and we studied it using scanning electron microscopy. EGF was released from the EGF-CPS for 8 weeks in an in vitro system. In animal studies, the EGF group, which was treated with EGF-CPS, showed healing in 56.5% of the animals (13/23), while the control group, which did not receive any treatment, revealed 20.8% healing (4/24) (p=0.04). Transmission electron microscopic studies of regenerated eardrums in the EGF group showed much greater preservation of histological features, and TMs of the EGF group were thinner than spontaneously healed TMs. In conclusion, this novel EGF-CPS can be used as a nonsurgical intervention technique for treatment of chronic TM perforations.

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.

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.

Biocompatibility evaluation of cigarette and carbon papers used in repair of traumatic tympanic membrane perforations: experimental study

The purposes of this study were to investigate the biocompatibility of two different paper patches (carbon and cigarette papers) and compare the adhesion and proliferation features of L929 fibroblast cells by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT Test) test and scanning electron microscopy (SEM). In this study, time-dependent cytotoxic effects of cigarette and carbon papers used in repairing small traumatic TM perforations were investigated in vitro by using MTT test. And also adhesion and spreading of cells over disk surface were observed by SEM. Cytotoxicity test carried out by MTT analysis on leakage products collected from two types of paper patches at the end of 24 and 48 h revealed no cytotoxicity (P > 0.05). In SEM studies, it was observed that cells started to proliferate over disk surface as a result of 48-h incubation, and SEM revealed that the cell proliferation over cigarette paper was more compared to the one over carbon paper. We believe that this is the first study where biocompatibility and adhesion features of carbon and cigarette paper have been studied by using L929 fibroblast cell culture. As a result, biocompatibility of cigarette paper and also whether cigarette paper was superior to carbon paper in cell attachment and biocompatibility were studied. It was found, by MTT test and SEM test, that cigarette paper had a higher biocompatibility and cell attachment, and thus cigarette paper should be the patch to be preferred in cases where TM perforations are repaired by paper-patch method.

Keratinocyte growth factor 1, fibroblast growth factor 2 and 10 in the healing tympanic membrane following perforation in rats

The aim of this study was to provide a transcriptome profile of Keratinocyte Growth Factor (KGF)-1, Fibroblast Growth Factor (FGF) 2 and FGF10 (KGF2) in the healing rat tympanic membrane (TM) over 7 days and an immunohistochemical account over 14 days following perforation. KGF1, FGF2, and FGF10 play important roles in TM wound healing. The tympanic membranes of rats were perforated and sacrificed at time points over a 14-day period following perforation. The normalized signal intensities and immunohistochemical protein expression patterns at each time point for KGF1, FGF2, and FGF10 are presented. The primary role of both KGF1 and FGF2 appeared to be in the proliferation and migration of keratinocytes. Whereas the role of KGF1 appeared to be exclusively concerned with increased proliferation and migration at the perforation site, the continued expression of FGF2, beyond perforation closure, suggested it has an additional role to play. FGF10 (KGF2), whilst possessing the highest sequence homologous to KGF1, has a different role in TM wound healing. The effect of FGF10 on keratinocytes in wound healing appeared to emanate from the connective tissue layer.

The role of epidermal growth factor in the healing tympanic membrane following perforation in rats

Epidermal Growth Factor (EGF) has been identified as playing a critical role in the wound healing process. The objective of this study is to investigate the role that EGF plays in rat tympanic membrane (TM) wound healing using two techniques, microarray and immunohistochemistry. The tympanic membranes of rats were perforated using a sterile needle and sacrificed at time points during 2 weeks following perforation. The normalized signal intensities at the time points for EGF and associated genes are presented. The rat EGF mRNA did not change significantly between time points. Five associated proteins, including heparin-binding EGF-like growth factor were found to be differentially expressed above a two fold threshold at 12 h following perforation. EGF staining was found at low levels in the uninjured TM. Levels of EGF staining increased at 24 h in the basal keratinocyte layer, became diffusely elevated in the specimen at 36 h, before a second peak in staining of the keratinocyte layer at Day 4. The staining of EGF corresponds to its multiple roles in TM wound healing.

Development of water-insoluble chitosan patch scaffold to repair traumatic tympanic membrane perforations

Perforated tympanic membranes (TM) and otitis media can be managed with a paper patch or tympanoplasty. However, a paper patch is not biocompatible and tympanoplasty requires complex aseptic surgical procedures. A novel biocompatible patch with a water-insoluble chitosan as the main component was prepared. Optimal mechanical characteristics of a water-insoluble chitosan patch scaffold (CPS) was approximately 40 microm in thickness, 7 MPa in tensile strength, and 107% in percent elongation, even though the characteristics varied significantly depending on the concentrations of chitosan and glycerol. SEM of the CPSs showed a very smooth surface as compared with that of the paper patches. These CPSs showed no cytotoxicity and had a stimulating effect on the proliferation of TM cells in in vitro study. In in vivo study, 4 (21.1%) and 17 (89.5%) TMs out of 19 adult rats with CPSs showed no perforations at 1 and 2 weeks, respectively. However, left control TMs showed healing of 0 (0%) at 1 week and 18 (94.7%) at 2 weeks. TEM findings of regenerated eardrums using CPSs showed thinner, smoother, and more compact tissues than spontaneously healed eardrums. A CPS was more effective than spontaneous healing to repair traumatic TM perforations.

[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.

Delay of tympanic membrane wound healing in rats with topical application of a tyrosine kinase inhibitor

An animal model of chronic tympanic membrane (TM) perforation is needed for experiments on supporting wound healing of TM perforations. The epidermal growth factor receptor (EGFR) has been implicated in the regulation of wound healing. The object of this study was to investigate the efficacy of topical EGFR-inhibitor (erlotinib) to arrest wound healing of experimental TM perforation in rats. Bilateral instrumental myringotomies were performed in 13 male rats. A solution of erlotinib (10 mg/mL) was applied to one TM of each animal and vehicle only (control group) to the other side. The application procedure was repeated on both sides daily for 12 consecutive days. Thereafter, tympanic membranes were observed weekly for a total of 30 days. The mean healing period was found to be 12.1 days in the group with erlotinib and 6.4 days in the control group. The difference was significant. We observed differences in the histologic parameters between erlotinib group and control group. The inhibition of EGFR by topical application of erlotinib did delay the healing rate of myringotomies but seems not to be suitable to create a chronic TM perforation in rat.

Hyaluronic acid ester in myringoplasty

Objectives:

To investigate the use of a new technique to close persistent tympanic membrane perforations under general anaesthesia, in patients in whom this has previously been considered impractical.

Design:

Twenty patients aged 50 years and over were recruited. All had a persistent, symptomatic tympanic membrane perforation in at least one ear. Pre-operatively, an audiogram was performed and the tympanic membrane was assessed in order to establish the site and size of the perforation. Under general anaesthesia, the edges of the perforation were freshened and a sheet of Epifilm, trimmed to a size roughly 2 mm larger in diameter than the perforation, was tucked through the perforation. The ear was dressed appropriately. Patients were seen two weeks post-operatively in the out-patients department and reassessed.

Setting:

The study was based at Poole General Hospital, a District General Hospital.

Participants:

Twenty patients were recruited from the out-patients clinics of Poole Hospital ENT department.

Main outcome measures:

(1) closure of the perforation, as a percentage of the original size; (2) improvement of hearing, as an average across all frequencies, expressed in dB hearing level; and (3) presence or absence of discharge.

Results:

Five patients were operated upon and assessed six weeks post-operatively. The Epifilm had dissolved but the perforations remained the same size in all five patients. There were no other adverse effects. Pure tone audiometry at this stage was redundant. The study was subsequently aborted.

Conclusions:

The authors conclude that repair of tympanic membrane perforations with hyaluronic acid ester films is not to be recommended.

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.

Effectiveness of MeroGel hyaluronic acid on tympanic membrane perforations

CONCLUSIONS

Our results support the proposition that hyaluronic acid (HA) provides a moist wound-healing environment to aid in the healing process of tympanic membrane perforation. A single MeroGel administration can be effective as well as daily topical HA application in the treatment of tympanic membrane perforations. A single application of esterified HA may be more suitable for patients and also for otolaryngologists.

OBJECTIVE

The purpose of the present study was to evaluate the effectiveness of a single MeroGel application on traumatic tympanic membrane perforations in rats.

MATERIALS AND METHODS

The posterior quadrant of the tympanic membranes in both ears of 24 male pathogen-free Sprague-Dawley rats was perforated with a 20-gauge needle. Subjects were divided into two groups: MeroGel and daily topical HA-treated groups. All subjects were sacrificed and histopathological examinations of the tympanic bullas were carried out.

RESULTS

Perforations of controls, and MeroGel- and daily HA-treated groups closed in 17/24 (70.8%), 11/12 (91.7%), and 12/12 (100%) ears, respectively. There was a significant difference between control and MeroGel-treated groups, and also between control and daily topical HA-treated groups for the presence of vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), lymphocytes and collagen fibrils (p<0.05), whereas there was no significant difference between MeroGel- and daily topical HA-treated groups (p>0.05).

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.

[An improved animal model for chronic perforation of the tympanic membrane]

BACKGROUND

An inexpensive and valid animal model of chronic tympanic membrane perforation is needed.

METHOD

Twelve male rats were selected for different surgical procedures (subtotal tympanic membrane perforation with local microflaps, re-perforation without flaps, partial excision of the handle of malleus). The inhibition of spontaneous healing was accomplished by the application of prednisolon or mitomycin directly onto the tympanic membrane.

RESULTS

Only by additional partial excision of the handle of malleus followed by local application of mitomycin were we able to achieve a persistent tympanic membrane perforation.

CONCLUSION

Chronic tympanic membrane perforation using this procedure may be useful in further investigations of the medical impact of tympanic membrane healing.