Chronic Tympanic Membrane Research Articles

Poly(glycerol sebacate)-engineered plugs to repair chronic tympanic membrane perforations in a chinchilla model

Objective To evaluate the degree of neovascularization and efficacy of repair of chronic tympanic membrane perforations in a chinchilla model using poly(glycerol sebacate) (PGS), a novel bioengineered scaffold material. Study Design A feasibility study in which chinchilla ears with chronic perforations were randomly assigned to repair with PGS plugs or Gelfilm overlay myringoplasty. Setting Interventions were performed in the animal care facility of a tertiary care academic institution. Subjects and Methods Sixteen adult female chinchillas. Perforations were established under microscopic visualization with thermal cautery. The animals were examined six weeks later, and those ears with stable perforations were randomly assigned to repair with PGS or Gelfilm. All ears were evaluated six weeks after repair, and resected membranes underwent histological evaluation. Results Chronic perforations were established in 22 of 32 (69%) chinchilla tympanic membranes. Nineteen tympanic membranes were included in the study group (3 ears were excluded secondary to death from anesthesia during the repair); 11 were implanted with PGS, and eight underwent Gelfilm myringoplasty. Of the 11 tympanic membranes implanted with PGS, 10 were healed at six weeks, while six of the eight tympanic membranes repaired with Gelfilm had healed at six weeks. Imaging of the medial mucosal and lateral epithelial surfaces of the tympanic membranes revealed PGS plug incorporation with neovascularization. Histology demonstrated a confluent cell layer on both sides of the graft. Conclusions PGS plugs are easily placed and allow for perforation closure and graft neovascularization in a chinchilla model.

Expression of Fibroblast Growth Factor Receptors 1–4 in Human Chronic Tympanic Membrane Perforation

Objective: To locate fibroblast growth factor receptor (FGFRs) 1–4 in human chronic tympanic membrane (TM) perforation. Methods: A sample of human chronic TM perforation was harvested during myringoplasty. The sample was immediately fixed in 4% paraformaldehyde and embedded in OCT compound. Immunohistochemistry was performed with FGFR 1–4 polyclonal antibodies. Results: FGFRs 1–4 were strongly and weakly expressed in the epidermal and mucosal layer of the TM perforation, respectively. Conclusions: As it is impossible to perform quantitative analysis based on the fluorescence intensity of each immunoreactivity, the presence of FGFRs 1–4 in the human chronic TM perforation is shown. The expressions of FGFRs 1–4 indicated that the clinical use of bFGF agent is useful for myringoplasty.

Basic Fibroblast Growth Factor Combined With Atelocollagen for Closing Chronic Tympanic Membrane Perforations in 87 Patients

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

Comparison of Porcine Acellular Dermis and Dura Mater as Natural Scaffolds for Bioengineering Tympanic Membranes

Tympanic membrane (TM) perforation is a frequent cause of conductive hearing loss. The most popular surgical repair is autografting with temporalis fascia, although some disadvantages have been found with this method. Whether xenogeneous grafts produced by a tissue engineering approach could be used is unclear. The purpose of this study was to evaluate the possibility of bioengineering TM using porcine acellular dermis and dura mater with TM fibroblasts and to compare the effects of these two natural scaffolds. Both of the materials were prepared by sequentially using Triton X-100, nuclease solution, and freeze-drying technique. Histologically, both had porous structures without any cellular components. After seeding with TM fibroblasts isolated from guinea pigs, it was found that both of the materials could be used as scaffolds for bioengineering TM in vitro. In the in vivo study, chronic TM perforation models were successfully established in guinea pigs. From gross and histological examinations, most of TM perforations were healed after grafting these two bioengineered TMs using an underlay technique. Furthermore, auditory brainstem response audiometry was applied to determine the auditory threshold in each group. Results showed that hearing in the dura mater group seemed to undergo faster recovery in the early stage but in the end, no differences were found between the two groups. Two kinds of materials without cell seeding were used as controls. Porcine acellular dermis and dura mater are suitable scaffolds for bioengineering TMs.

Complications of otitis media in Indigenous and non‐Indigenous children

In Australia, three to five children die each year because of otitis media complications, and 15 children will suffer permanent hearing loss each year as a result of otitis media. Extracranial complications occur most commonly, and include mastoiditis, cholesteatoma and otitis media with perforation. Intracranial complications are less common, and include meningitis, brain abscess and lateral sinus thrombosis. In Australia, approximately 60% of extracranial and intracranial complications of otitis media occur in children. The contrasting rates of childhood otitis media among Indigenous and non-Indigenous children have implications for the frequency and types of complications occurring in both groups. Otitis media with effusion and acute otitis media predominate among non-Indigenous children, whereas chronic suppurative otitis media (CSOM) occurs most commonly among Indigenous children. The incidence of mastoiditis in Australia is low by international standards (2/100,000 children), but cholesteatoma rates among Indigenous children in Australia are higher than previously estimated (up to 10% in CSOM). A high rate of chronic tympanic membrane perforation occurs among Indigenous children, estimated to be as high as 80%. Intracranial complications of otitis media are uncommon, but are potentially life-threatening and are more likely to occur among Indigenous than non-Indigenous children. Reduced access to medical care, lower socioeconomic status and remote living conditions mean that levels of early childhood hearing loss among Indigenous children are likely to be underestimated. This has implications for early childhood speech and language development and education.

Preliminary results of the application of a silk fibroin scaffold to otology

The surgical treatment to repair chronic tympanic membrane perforations is myringoplasty. Although multiple autologous grafts, allografts, and synthetic graft materials have been used over the years, no single graft material is superior for repairing all perforation types. Recently, the remarkable properties of silk fibroin protein have been studied, with biomedical and tissue engineering applications in mind, across a number of medical and surgical disciplines. The present study examines the use of silk fibroin for its potential suitability as an alternative graft in myringoplasty surgery by investigating the growth and proliferation of human tympanic membrane keratinocytes on a silk fibroin scaffold in vitro. Light microscopy, immunofluorescent staining, and confocal imaging all reveal promising preliminary results. The biocompatibility, transparency, stability, high tensile strength, and biodegradability of fibroin make this biomaterial an attractive option to study for this utility.

Novel repair of chronic tympanic membrane perforations

Novel repair of chronic tympanic membrane perforations

Repair of the tympanic membrane with urinary bladder matrix

To test urinary bladder matrix (UBM) as a potential treatment for tympanic membrane (TM) healing and regeneration. This prospective pilot study was designed to provide both qualitative and semiquantitative assessment of temporal and spatial healing events in the chinchilla model of chronic TM perforations with and without UBM patching. Bilateral myringotomies were performed and repeated as necessary to create subtotal perforations over an 8-week period. Myringoplasty was then performed, with left TMs serving as controls and right TMs receiving UBM patches. TMs were excised at 4 weeks, 8 weeks, and 12 weeks. Fixed tissue samples were characterized for gross morphology, then processed for microscopic evaluation. Chronic perforations were maintained with one or more repeated myringotomies. Although both control and patched TMs were thicker than native tissue, patched TMs were transparent and uniform in thickness without any inclusions. UBM patches were readily degraded and replaced by newly deposited and organized host tissue that recapitulated the native TM layers. UBM scaffolds were an effective biological scaffold for TM closure and tissue remodeling, leading to thicker than normal anatomy but otherwise normal morphology. Future studies are required to determine functional and temporal outcomes as well as alternative patch orientations. The results show particular promise as a superior alternative means of reconstructing not only chronic TM perforations but also dimeric TMs associated with retraction pockets and atelectasis. Laryngoscope, 2009.

Evaluation of a model for studies on sequelae after acute otitis media in the Mongolian gerbil

Conclusions. The model appears relevant for studies on sequelae after acute otitis media (AOM), and may be the seed of a new, chronic tympanic membrane perforation model in the gerbil. Objectives. To evaluate an experimental model for abortive otitis media and to assess the structural and functional changes of the tympanic membrane in the resolving phase. Materials and methods. The middle ears of 16 Mongolian gerbils were inoculated with type 6a Streptococcus pneumoniae. Half of the animals were treated with antibiotics on days 4–6, when otoscopy was performed as well. After 1, 2, 3 or 4 weeks the animals were sacrificed and their tympanic membranes were examined by otoscopy, dissection microscopy, light microscopy and moiré interferometry. Results. On days 4 and 6 AOM was produced in approximately 80% of the animals and perforations prevailed in approximately 30% at the study end points. Clinical signs of AOM and oedema of the tympanic membrane had already started to reduce after 1 week, and often resolved within 2 weeks. The mechanical stiffness of the tympanic membrane remained relatively unharmed in the non-perforated ears. The antibiotic treatment seemed to reduce the duration of oedema but not the perforation rate.

Autologous Serum Eardrops Therapy With a Chitin Membrane for Closing Tympanic Membrane Perforations

Office treatment for chronic tympanic membrane (TM) perforations has limitations, and alternative methods to myringoplasty are sometimes needed. Serum lacks antigenicity and contains a large variety of growth factors known to modulate proliferation of various tissues to promote wound healing effects. Our purpose was to evaluate the feasibility of autologous serum eardrops therapy with a chitin membrane for closing TM perforations. In the outpatient clinic, the perforation margin was cauterized with silver nitrate, and the perforation was covered with a chitin membrane. Patients were instructed to apply autologous serum eardrops daily. Patients were examined every 2 weeks, and the procedure was repeated. We treated 19 sequential patients with chronic TM perforation in 1 ear between October 2005 and September 2007. Closure of the TM was achieved in 11 (58%) of 19 ears, and reduction of the perforation size was observed in 2 ears (11%). Closure rates for small, medium, and large perforations were 57 (8 of 14), 0 (0 of 1), and 75% (3 of 4), respectively. Closure rates for perforations attributable to intratympanic dexamethasone treatment, after myringoplasty and chronic otitis media were 67 (2 of 3), 67 (2 of 3), and 54% (7 of 13), respectively. Time for closure took from 15 to 175 days, with an average of 68 days (5.9 clinic visits). During autologous serum eardrop therapy with a chitin membrane, no remarkable side effects in the treated ears were observed. Measurement of the concentration of the epidermal growth factor, transforming growth factor beta1, fibronectin, and interleukin 6 in the serum showed no decrease in 14 days, suggesting activity remained stable in that period. Autologous serum eardrops therapy with a chitin membrane, which requires no surgical intervention, was found to be a promising office-based technique for the closure of chronic TM perforations because of its ease, safeness, and feasibility. However, additional studies are needed to independently analyze the specific benefits of the serum drops and the chitin membrane.

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.

Comparison of paper-patch, fat, and perichondrium myringoplasty ın repair of small tympanic membrane perforations

To compare the effectiveness of paper-patch, fat, and perichondrium myringoplasty in the treatment of chronic tympanic membrane perforations smaller than 3 mm. This investigation included 45 patients with chronic tympanic membrane perforations smaller than 3 mm. The patients were equally divided into 3 main groups according to surgical procedures. Each group consisted of 3 subgroups, which had 1-mm, 2-mm, and 3-mm perforations. The patients underwent paper-patch, fat, or perichondrium myringoplasty via transcanal approach under local anesthesia. Healing of perforation, hearing improvement, and complications were investigated. Closure rates of the perforations in the paper-patch, fat, and perichondrium myringoplasty groups were 66.7%, 86.7%, and 86.7%, respectively. There were no statistically significant differences in tympanic membrane closure rates between techniques with regard to size. Three techniques were found to be feasible for tympanic membrane perforations smaller than 3 mm.

Paper-patch myringoplasty with CO2 laser for chronic TM perforation

Chronic tympanic membrane (TM) perforations are a common problem in otolaryngology. However, there are controversies of how best to treat TM perforation. Recently, we successfully managed TM perforation with paper patch after trimming the perforated TM margin with the CO2 laser. The purpose of this report is to demonstrate the trial of this method and effectiveness. The authors conducted a retrospective case series from March 2000 to January 2005. Ninety patients underwent paper-patch myringoplasty with the CO2 laser. The procedure was performed in an office setting under local anesthesia. We investigated perforation size and postoperative success rate. Successful closure of the TM was achieved in 52.2% of cases (47/90) without any severe complication. The procedure was successful in 16 of 19 (84.2%) cases in perforation smaller than 2 mm, 19 of 29 (63.0%) cases when the size was 2-4 mm, 10 of 25 (40.0%) cases when the size was 4-6 mm, and 2 of 17 (11.8%) cases when the size was > or =6 mm. A significant difference was found: Perforation with <4 mm had the higher closure rate (chi2 test, P < 0.01). There was no correlation between the size of perforation and the number of patch graft (chi2 test, P > 0.05). The results showed paper-patch myringoplasty after CO2 laser trimming is simple and safe to perform, and suitable as an outpatient procedure, especially in small perforations (<4 mm).

Lack of plasminogen does not alter the early inflammatory response following a tympanic membrane perforation: a study in plasminogen-deficient mice

Conclusions. The results of the present study show that the early inflammatory response in plasminogen (plg)-deficient mice is not altered compared to that in wild-type (wt) mice. Therefore the chronicity of the perforation in the long-term healing experiment cannot be explained by an impairment of the early inflammatory response, but rather by an impairment in activation of the inflammatory cells. These findings give further insight into the mechanisms resulting in a clinically seen chronic tympanic membrane (TM) perforation and thus possible therapeutic strategies to replace today's conventional surgical treatment of these perforations. Objectives. Plg has been shown to play an essential role in the healing of TM perforations. In plg-deficient mice a completely arrested healing reaction was seen, resulting in a chronic TM perforation. The mechanisms involved seem to be an abundant neutrophil recruitment, an accumulation of macrophages, an arrested keratinocyte migration, and a massive deposition of fibrin along the TM tissue. However, the exact functional role of plg in the early inflammatory response during healing of TM perforation remains unclear. This study aimed to evaluate the early inflammatory response, mainly the occurrence of macrophages and neutrophils, during the first 48 h following a perforation in the pars tensa (PT) of the TM, in mice lacking the plasminogen gene compared to the corresponding response in wt mice. Materials and methods. The TMs were perforated in 45 plg-deficient and 39 wt mice. Otomicroscopic evaluation was performed at 3, 6, 9, 12, 18, 24, and 48 h after the perforation was made. Mice were harvested at all time points and prepared for morphology including immunohistochemistry (IHC). IHC was performed with antibodies targeting macrophages, neutrophils, T and B cells, cytokeratin, and fibrin(ogen). Morphometry was performed regarding the volume percentage of TM tissue occupied by the different inflammatory cells. Results. Perforation of the TM resulted in early otomicroscopic changes of the pars flaccida (PF) in both genotypes. Infiltration of inflammatory cells to PF and the presence of edema occurred as early as 6 h after the perforation was made, in both plg-deficient and wt mice. Morphometry did not reveal any significant differences between the genotypes concerning the occurrence of inflammatory cells. In contrast to the PF, the PT showed only sparse reactions during the experimental period. Furthermore, the migration pattern of keratinocytes did not differ between the genotypes throughout the experimental period.

Stem cells and enhanced healing of chronic tympanic membrane perforation

Conclusions. Important information about the basic reparative process of tympanic membrane (TM) healing is shown, which can be incorporated for further clinical understanding. This provides a basis for the exploration of stem cell treatment for TM perforations and holds promise for future improvements. Objectives. This study aimed to analyse the healing of TM perforation by using stem cells and the stiffness of the membrane was tested in an acute and long-term study. Materials and methods. Sprague-Dawley rats were used in a model of TM perforation. The perforation was performed with a laser system. Stem cells were applied and the healing time and morphological analysis were performed with light and transmission electron microscope. Stiffness was examined by moiré interferometry. Results. The stiffness of the perforated and healed TM was restored after just 2 weeks. In the chronic perforation model, mesenchymal stem cells enhanced the healing.

Chronic tympanic membrane perforation: a better animal model is needed

Developments in the treatment of chronic tympanic membrane perforation have been hindered by the lack of an ideal animal model. It is not appropriate to test such treatments on acute perforations as the majority of these heal spontaneously. An ideal animal model would be one that most closely resembles the human clinical situation. It should be inexpensive, readily available, and easy to create. There have been a number of attempts to create a chronic tympanic membrane perforation model with limited success. All published attempts at chronic tympanic membrane perforations have been reviewed and the limitations of each model are discussed. A number of areas for research exist for further developing a chronic tympanic membrane perforation model. These areas include a perforation model in the presence of bacteria and eustachian tube dysfunction. Understanding the molecular and genetic mechanisms of chronic otitis media and potential treatments will also be useful.

Prävalenz chronischer Trommelfellperforationen in der erwachsenen Bevölkerung

The goal of this study was to evaluate the prevalence of chronic tympanic membrane perforation in the adult population. The study population included 1,000 subjects (453 males, 547 females) aged 18-93 years. In addition to interview data, ear examinations were performed. There were eight subjects with unilateral chronic tympanic membrane perforation and a single subject with a bilateral perforation. The age adjusted prevalence of chronic tympanic membrane perforation was 0.45% (95% confidence interval: 0.03-0.87). Eight out of nine subjects disliked tympanoplasty. The high proportion of subjects with chronic tympanic membrane perforations who do not want to be operated suggests that there is a considerable need for novel therapeutic procedures.

Inhibition of Epidermal Growth Factor Receptor by Erlotinib

Inhibition of epidermal growth factor receptor (EGFR) may arrest wound healing of experimental tympanic membrane perforation in rats. An animal model of chronic tympanic membrane perforation is needed for experiments on supporting wound healing of tympanic membrane perforations. The EGFR has been implicated in the regulation of wound healing. Thirty animals were administered 80 or 40 mg/kg/d EGFR tyrosine kinase inhibitor, or vehicle only for 5 days. The right-sided tympanic membrane of each animal was perforated at Day 2. Rat ears were inspected repeatedly to analyze the status of perforation. Tympanic membranes were examined histologically. Unfortunately, five animals in the 80-mg/kg group and four in the 40-mg/kg group died before they reached their scheduled endpoint. Taking into account the small sample sizes, we observed a delayed closure of perforations in the 80-mg/kg group and differences in the histologic parameters between treated groups and control group. The inhibition of EGFR by systemic application of erlotinib seems not to be suitable to create a chronic tympanic membrane perforation in rat.

Tissue‐Engineered Calcium Alginate Patches in the Repair of Chronic Chinchilla Tympanic Membrane Perforations

Chronic tympanic membrane perforations are a common problem in the United States. A high number of these cases results from placement of pressure equalization tubes. These perforations may initially be treated with paper patch techniques and although safe and well tolerated, the procedure demonstrates poor efficacy. The ideal treatment for small perforations should be rapid, minimally invasive, and efficacious. Calcium alginate-based tissue engineered tympanic membrane patches represent an attractive option, but in vivo data are required. A controlled prospective study of tympanic membrane perforation repair using a well-known chinchilla model of chronic tympanic membrane perforation was performed. Calcium alginate-based tympanic membrane patches were created using computer-aided design techniques. A previously described chinchilla model of chronic tympanic membrane perforations was used to create stable perforations ranging from 2 to 5 mm. Ears with chronic perforations were divided into three groups: control (no patch), paper patch, and calcium alginate plugs. At 10 weeks postimplantation, all animals were killed and inspected both grossly and histologically for healing. In the chinchilla model, the alginate grafts demonstrated significantly improved healing rates over both the untreated control group (spontaneous repair) and the paper patch group; nine of 13 healed in the alginate group versus two of nine healed in the paper patch group (P < .05) versus one of 11 healed in the control group (P < .05). Calcium alginate tympanic membrane perforation patches offer a significant advantage in the repair of chronic perforations over traditional techniques in the chinchilla perforation model and may offer attractive opportunities in the clinical setting.

Fat Graft Myringoplasty: Results of a Long-Term Follow-Up

To evaluate the long-term results of fat graft myringoplasty in adult and pediatric populations. Prospective case series study. Patients with chronic tympanic membrane perforations were considered candidates for fat graft myringoplasty. Excluded were patients with purulent discharge, suspected ossicular disease, suspected cholesteatoma, or a perforation diameter greater than 6.5 mm. Fat was harvested from the ear lobule or subcutaneous tissue just posterior-inferior to the lobule. The study population comprised 27 adults and 11 children. Twenty-eight perforations were small (73.7%) and 10 were large (26.3%). Altogether, 31 of 38 perforations were successfully repaired (81.6%), including 22 of 28 small perforations (78.6%) and 9 of 10 large perforations (90%). Assessment by age showed that 23 of 27 perforations of the adults (85.2%) and 8 of 11 perforations of the children (72.7%) successfully closed (p = .648). Follow-up ranged from 25 to 53 months (mean 40.6 +/- 8.3 months). No recurrence of the perforation during the follow-up period was recorded if the initial results were successful. The speech reception threshold improved significantly (18.5 +/- 7.7 dB vs 23.5 +/- 8 dB; p = .043). No significant sensorineural hearing loss occurred. Fat graft myringoplasty is a reliable technique for the closure of small- and medium-sized perforations. The grafting results showed excellent long-term durability. Given the simplicity of the technique, its short duration, and the favourable hearing results, fat graft myringoplasty should be considered the procedure of choice in patients with suitable perforations and when not otherwise contraindicated.