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The perforated tympanic membrane.

Tympanic membrane perforations typically result from trauma or acute otitis media. Most perforations do not cause more than a mild conductive hearing loss, aural fullness and mild tinnitus. Blood, purulent secretions and other debris should be carefully suctioned out of the canal and the perforation size and location described. Irrigation and pneumatic otoscopy should be avoided. A history of vertigo, nausea and vomiting and an audiogram showing a conductive hearing loss of more than 30 dB suggest disruption of the ossicular chain. Profound sensorineural loss may signify inner ear nerve damage. Mastoid radiographs and computed tomographic scans may be useful in cases of significant trauma and infection. Most small perforations resolve spontaneously. The affected ear should be kept dry. Oral and topical antibiotics may be prescribed for perforations related to acute otitis media. Otolaryngologic referral may be necessary to evaluate traumatic perforations associated with vertigo or significant hearing loss, perforations from chronic otitis media or perforations from acute otitis media that do not heal within one month.

Ear Diseases↗

Tympanic membrane changes in central tympanic membrane perforations.

PURPOSE: The objective of this study was to evaluate the histopathological changes in central tympanic membrane perforations caused by chronic otitis media without cholesteatoma. MATERIALS AND METHODS: Twenty-nine temporal bones from 25 patients (13 male patients and 12 female patients) with central tympanic membrane perforations-18 chronic otitis media with perforation and 11 chronic otitis media with perforation caused by ventilation tubes-and 30 aged-matched normal temporal bones were included in this study. A scale was used to evaluate the extension of the migration of stratified squamous epithelium in the inner surface of the tympanic membrane. The thickness of tympanic membranes was measured halfway between the annular ligament and the perforation and compared with that of the normal bones. The presence of tympanosclerosis and papillary projections of squamous epithelium was also noted. RESULTS: The extension of the migration of stratified squamous epithelium in the inner surface of the tympanic membrane was observed in 11 of the 29 perforations (38%). The thickness of tympanic membranes was significantly different between the perforation groups and the control group. Of the 29 tympanic membranes, 13 (44%) had tympanosclerosis and 8 (28%) revealed papillary projections of squamous epithelium. CONCLUSIONS: Our study shows that a central tympanic perforation should not merely be considered as a simple defect. Most of the tympanic membranes showed one or more signs of sequelae or persistent abnormalities such as tympanosclerosis, papillary projections, thickening, and ingrowth without significant differences between the 2 central perforation groups.

Adolescent↗

Cholesteatoma behind an intact tympanic membrane: histopathologic evidence for a tympanic membrane origin.

BACKGROUND: Several theories have been proposed with respect to the origin and pathogenesis of cholesteatoma behind an intact tympanic membrane. CASE REPORT: The authors describe a case of cholesteatoma behind an intact tympanic membrane in a 71-year-old man with a history of tympanic membrane retraction fixed to the incus without evidence of a perforation. The membrane eventually became detached, and remnants of keratinizing squamous epithelium were found on the incus. DISCUSSION: Mechanisms such as metaplasia, ectopic epidermis rests, or ingrowth of meatal epidermis have been proposed to explain the pathogenesis of cholesteatoma behind an intact tympanic membrane. These findings, based on temporal bone histopathology, support the role of an acquired epidermal rest. CONCLUSIONS: This case report provides evidence that cholesteatoma behind an intact tympanic membrane can be established from a resolved retraction of the pars tensa of the tympanic membrane.

Aged↗

Histological study of the thin replacement membrane of human tympanic membrane perforations.

A histological study was done on the thin, nearly transparent replacement membrane of tympanic membrane perforations. Human tympanic membranes that were rejected for transplantation, were studied by light and electron microscopy. The abrupt reduction in thickness at the margin of the covered perforation, is entirely due to the reduction of the lamina propria. Even in the thinnest parts of the replacement membrane, a lamina propria is present, separated by continuous basement membranes from the epithelium and mucosa, and measuring no more than some 2-3 microns in thickness. This lamina propria consists of fibrils and interfibrillar matrix, but fibroblasts appear to be lacking. The epithelial layer does not contain basal cells, confirming the thesis that the upper layers are not generated by in situ proliferation, but that they have migrated from the periphery.

Humans↗

The collagen structure of the tympanic membrane: collagen types I, II, and III in the healthy tympanic membrane, during healing of a perforation, and during infection.

OBJECTIVE: To analyze the distribution of 3 collagen types in healthy tympanic membranes, during healing of a perforation, and during infection. DESIGN: Immunohistochemical study of collagen types I, II, and III in the tympanic membranes of healthy rats as well as during healing of a perforation and in the presence of infection with Streptococcus pneumoniae at various time points. SETTING: Laboratory research center at a university hospital. RESULTS: Type II collagen was a main constituent of the lamina propria of the pars tensa, whereas type I collagen was found mainly in the pars flaccida. Collagen types I and III were found at the insertion to the malleus handle and in the loose connective tissue surrounding the main collagen layer of the pars tensa. After myringotomy, collagen types I and III were found at the perforation border and around dilated blood vessels early in the healing phase. During infection, the collagen layer was thickened and stained strongly for type II collagen. Collagen types I and III were found in the edematous connective tissue around the main collagen layer and around dilated blood vessels. Three months after perforation or infection, all 3 collagens were present in the lamina propria of the tympanic membrane. Extensive amounts of all 3 collagen types were present in the scar tissue in the tympanic membranes of rats that had undergone myringotomy during the presence of acute otitis media. CONCLUSIONS: The lamina propria of the pars tensa is mainly made up of type II collagen, whereas type I collagen is found in the pars flaccida. Thus the fibrous structure of the pars tensa and flaccida is composed of diverse collagen types, which reflects the different physiological properties of these tissues. Collagen types I and III are present in the acute healing phase after myringotomy and infection, and the collagen content of the tympanic membrane is modified during the inflammatory and healing process.

Animals↗

The effects of keratinocyte growth factor on healing of tympanic membrane perforations.

Tympanic membrane (TM) perforations heal by reepithelialization and fibrous layer proliferation. The rat TM model may be used to study growth factors that promote epithelialization and fibroblast proliferation, such as epidermal growth factor (EGF) and fibroblast growth factor (FGF). The authors previously evaluated the effects of FGF on tympanic membrane perforations and showed an enhanced rate of wound healing with preservation of normal structure and function. The same model was used to test keratinocyte growth factor (KGF, also called FGF-7). This growth factor has been shown to stimulate the migration and proliferation of keratinocytes. This is the first study investigating KGF in the tympanic membrane perforation model. Our results show that in contrast to FGF and EGF, KGF does not enhance the rate of wound healing, but rather results in a more organized wound repair process.

Animals↗

Tympanic membrane Patcher: a new device to close tympanic membrane perforations in an office setting.

OBJECTIVE: To assess a new device intended to cover tympanic membrane (TM) perforations in an office setting. STUDY DESIGN: Not all patients with TM perforations require or choose tympanoplasty surgery. Alternatives to surgery (e.g., paper and plastic onlay) have limitations that prompted a need for an alternative method. A new, simple device, designed to be inserted into the perforation, is made out of a very soft silicone in the shape of a sealed tympanostomy tube. The TM Patcher is self-stabilizing without adhesives. SETTING: An outpatient office. PATIENTS: Twenty-nine patients with 30 consecutive dry TM perforations, who volunteered to participate in the study. Patients with known cholesteatomas or persistent drainage were excluded. INTERVENTIONS: In the office, patients had the Patcher inserted into their dry TM perforation. No anesthetics were needed. MAIN OUTCOME MEASURES: Hearing was tested before and after patching by conventional audiometry. The ears were assessed for Patcher position, perforation status, and infection. RESULTS: Patients with normal ossicular chains had immediate improvement of hearing. No patient experienced hearing loss. Twenty-six of 30 patients (87%) were free of infection. Two patients (7%) with persistent drainage were taken to surgery and were found to have mastoid disease (cholesteatoma or granulation tissue). Three patients (10%) had rare otorrhea after patching and were treated by drops or temporary removal of the Patcher. Two of these three ears subsequently became dry and then healed. Small perforations often healed or became smaller (46% of 3-mm perforations) despite failure of tympanoplasty or conventional office patching with a flat piece of paper or plastic. Perforations >5 mm did not heal; however, these patients simply continued wearing their Patcher and benefited by protection of their middle ear, typically with improved hearing and resolution of tinnitus. Occasional spontaneous lateralization was allowed to occur in the small perforations, which often later healed. In larger perforations, the Patcher was simply repositioned. CONCLUSIONS: The Patcher is a safe and effective alternative for office patching of dry perforations when surgery is contraindicated or is refused by the patient. New materials should increase healing rates when applied to a Phase II Patcher.

Adolescent↗

The structure of the tympanic membrane: a new concept or some thoughts on the structure of the tympanic membrane and its presentation as a dynamic organ.

We have been taught that the tympanic membrane stretches across the end of the external auditory canal as a thin, taut drumhead passively vibrated by air borne sound. Much evidence supports this conception. However, I believe the tympanic membrane is a dynamic, complicated organ that is in many situations neither passive, thin, nor flat; a serous fluid accumulates within its middle layers, and often a double-convex shape is assumed. There are several phenomena that are not adequately explained by our present interpretation of tympanic membrane structure, and these are herein enumerated. I contend that the presence of a highly mobile fluid system within the drumhead resolves these questions. The search for historic evidence to support this concept involves both Dr. H. Shrapnell and Dr. H. Helmholtz. In 1832, Shrapnell wrote two articles for the London Medical Gazette in which he discredited the theories of Home and Albinus regarding the structure of the tympanic membrane. He described the pars flaccida and speculated on its function. He noted the mucosal layer of the pars flaccida was covered with mucus, while the pars tensa had a "glistening, shiny surface." The work of Dr. Helmholtz in 1863 and 1869 is perhaps even more pertinent. In years later his calculations projected a double-convex contour of the eardrum. As he could not reconcile these calculations with his original impressions, he deferred "...special description and discussion...in order that this experiment might be better performed." It is the purpose of this article to suggest that the tympanic membrane has a variables thickness related to physiologic need, and photography and scientific works by Nillson, Stenfors, McMinn, Taylor, Lim, Graham, and others are utilized to support this contention.

Humans↗

Viscoelastic properties of human tympanic membrane.

The tympanic membrane or eardrum of human ear transfers sound waves into mechanical vibration from the external ear canal into the middle ear and cochlea. Mechanical properties of the tympanic membrane (TM) play an important role in sound transmission through the ear. Although limited resources about linear elastic properties of the TM are available in literature, there is a lack of measurement or modeling of viscoelastic properties of the TM at low stress levels. In this study, the uniaxial tensile, stress relaxation, and failure tests were conducted on fresh human cadaver TM specimens to explore mechanical properties of the TM. The experimental results were analyzed using the hyperelastic Ogden model and digital image correlation method. The constitutive equation and non-linear elastic properties of the TM were presented by functions of the stress and strain at the stress range from 0 to 1 MPa. Viscoelastic properties of the TM were described by the stress relaxation function and hysteresis. The results show that the uniaxial tensile test with the aid of digital image correlation analysis is a reliable and useful approach for measuring mechanical properties of ear tissues. The data presented in this paper contribute to ear biomechanics in both experimental measurement and theoretical analysis of ear tissues.

Cadaver↗

Embryonic stem cells enhance the healing of tympanic membrane perforations.

OBJECTIVE: Tympanic membrane perforations may cause hearing impairment and otorhea. It is a common indication for ear surgery. The aim of the study was to test whether stem cells may enhance the healing of fresh tympanic membrane perforations. METHODS: In a first assay, the status of the tympanic membrane at 5 days after myringotomy was tested in five Mongolian gerbils that were treated on one side with embryonic stem cells and on the other side with control substance. In a second assay, nine gerbils were treated in the same way, except that fluorescent-labeled embryonic stem cells were used. The integration of the stem cells into the surface layer of the healing tympanic membrane was assessed with fluorescence microscopy, as well as the differentiation of these cells. RESULTS: In the first assay, all perforations in the treated ears were closed, whereas only two of the untreated ears were closed. The strength of the healed perforation was greater in the stem cell treated tympanic membranes (mean rupture pressure 120 daPa in three treated ears compared to 60 daPa in the one control ear). Two stem cell-treated tympanic membranes remained intact throughout the whole sequence of pressures, whereas only one control tympanic membrane remained intact. In three tympanic membranes in the second assay, a group of fluorescence-doped cells was detected in the region of the perforation. CONCLUSION: These findings indicate that stem cells enhance the healing of tympanic membrane perforations, possibly by differentiation and integration into the tympanic membrane tissue.

Animals↗

Nature of the tympanic membrane insertion into the tympanic bone of the rat.

The nature of the insertion of the tympanic membrane into the tympanic bone was studied in the rat during the developmental period ranging from 18 days post conception (dpc) to 40 days after birth (dab). Techniques applied were light microscopy, electron microscopy and immunohistochemistry with antibodies to cytoskeletal proteins: vimentin, desmin and alpha-smooth muscle actin (sma) as fibroblast differentiation markers. It was established that the cartilaginous annulus of the pars tensa was connected to the tympanic bone by an interface of specialised connective tissue. Both the fibrocartilage and the interface were derived from the embryonal mesenchyme between the tympanic ring and meatal plate. Electron microscopy showed that the interface was composed of two types of fibroblast. The majority of these cells were myofibroblasts, which were interconnected by junctions and had intimate contact with the collagenous fibres. A small number were identified as genuine fibroblasts. Cytoskeletal characterisation revealed the presence of three types of cell: V cells which expressed vimentin, VA cells which expressed vimentin and alpha-sma and VAD cells which expressed vimentin, alpha-sma and desmin. The myofibroblasts expressed antigens of both smooth muscle cells (alpha-sma, desmin) and connective tissue cells (vimentin). It is suggested that the pars tensa is connected to the tympanic bone by a network of contractile cells and fibres. Contraction will move the membrane in an outward direction and antagonise the inward retraction by the tensor tympani.

Actins↗

Effect of pentoxifylline on the healing of guinea pig tympanic membrane.

Although most tympanic membrane perforations heal spontaneously, persistent perforations frequently require treatment by otolaryngologists. Initial management strategies include keeping the ear dry, ensuring aural hygiene, and using topical antibiotics. For persistent perforations, paper patching or myringoplasty may be required. Recently, agents such as hyaluronic acid and epidermal growth factor have been used to promote tympanic membrane healing. Similarly, pentoxifylline, a pharmaceutical agent with hemorrheological and antithrombotic properties, has been shown to increase perfusion and accelerate wound healing. This double-blinded prospective study attempts to examine the effect of pentoxifylline on tympanic membrane healing of 50 guinea pigs subjected to myringotomy. Serial examinations and histopathologic sectioning of the tympanic membranes revealed no significant difference in rate of healing or quality of repair between the pentoxifylline and control groups.

Animals↗

Determinants of hearing loss in perforations of the tympanic membrane.

BACKGROUND: Although tympanic membrane perforations are common, there have been few systematic studies of the structural features determining the magnitude of the resulting conductive hearing loss. Our recent experimental and modeling studies predicted that the conductive hearing loss will increase with increasing perforation size, be independent of perforation location (contrary to popular otologic belief), and increase with decreasing size of the middle-ear and mastoid air space (an idea new to otology). OBJECTIVE: To test our predictions regarding determinants of conductive hearing loss in tympanic membrane perforations against clinical data gathered from patients. STUDY DESIGN: Prospective clinical study. SETTING: Tertiary referral center. INCLUSION CRITERIA: Patients with tympanic membrane perforations without other middle-ear disease. MAIN OUTCOME MEASURES: Size and location of perforation; air-bone gap at 250, 500, 1,000, 2,000, and 4,000 Hz; and tympanometric estimate of volume of the middle-ear air spaces. RESULTS: Isolated tympanic membrane perforations in 62 ears from 56 patients met inclusion criteria. Air-bone gaps were largest at the lower frequencies and decreased as frequency increased. Air-bone gaps increased with perforation size at each frequency. Ears with small middle-ear volumes, < or = 4.3 ml (n = 23), had significantly larger air-bone gaps than ears with large middle-ear volumes, > 4.3 ml (n = 39), except at 2,000 Hz. The mean air-bone gaps in ears with small volumes were 10 to 20 dB larger than in ears with large volumes. Perforations in anterior versus posterior quadrants showed no significant differences in air-bone gaps at any frequency, although anterior perforations had, on average, air-bone gaps that were smaller by 1 to 8 dB at lower frequencies. CONCLUSION: The conductive hearing loss resulting from a tympanic membrane perforation is frequency-dependent, with the largest losses occurring at the lowest sound frequencies; increases as size of the perforation increases; varies inversely with volume of the middle-ear and mastoid air space (losses are larger in ears with small volumes); and does not vary appreciably with location of the perforation. Effects of location, if any, are small.

Acoustic Impedance Tests↗