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At least 55 records · Page 3Linked to original sources

Symposium: Congenital anomalies of the middle ear. III. Congenital anomalies of the middle ear.

Congenital anomalies of the middle ear have been considered rare. The tremendous volume of middle ear surgery performed during the last 15 years has brought attention to numerous anomalies of the facial nerve, ossicles, and middle ear cleft, suggesting that middle ear anomalies are not as rare as once believed. This paper discusses anomalies of the descending and horizontal facial nerve which have been previously reported. The literature of anomalies of the ossicles is reviewed. A very rare anomaly of the carotid artery presenting in the middle ear is described and its surgical treatment outlined. Two anomalies of the middle ear associated with other branchial arch anomalies are reported and their treatment results discussed.

Adolescent↗

Transcanal management of benign middle ear lesions involving the anterior middle ear cleft.

The anterior middle ear has always been a difficult area to visualize and access. This report reviews the experience with a new approach to gain exposure of the middle ear. This technique involves separating the entire pars flaccida from the handle of the malleus for better exposure and then replacing the drum. Four patients were treated in this fashion; one glomus tympanicum, two congenital cholesteatomas, and one benign adenoma. All patients benefited from improved exposure and resection. No patients had postoperative laterialization of the drum and hearing was maintained.

Adenoma↗

The nasopharynx and the middle ear. Inflammatory reactions in middle ear disease.

The host-parasite interactions in the nasopharynx with bacterial colonization and antigen uptake in the lymphoid tissue, the adenoid, has an impact on the maturation of local and systemic immunity. The adenoid is a part of mucosa associated lymphoid tissue and is responsible for both effector and inductor functions in the nasopharynx. Increasing evidence supports the role of serum antibody in protecting the middle ear cavity from disease. There is evidence for a minor immunologic defect in a number of children with recurrent episodes of AOM.

Adenoids↗

Effect of increased middle ear pressure on blood flow to the middle ear, inner ear and facial nerve in guinea pigs.

We investigated the effect of increased middle ear pressure on blood flow to the inner ear, middle ear, and facial nerve in guinea pigs using a nonradioactive microsphere technique. The elevation of middle ear pressure significantly reduced blood flow to the middle ear. Blood flow to the facial nerve also decreased due to the elevation of the middle ear pressure but the reduction was not significant. Blood flow to the inner ear did not change even after the middle ear pressure was increased. Findings are discussed in relationship to aural barotrauma, alternobaric vertigo and facial baroparesis.

Animals↗

Middle ear pressure following tympanoplasty for various middle ear diseases. Pressure related to follow-up period and retractions.

In 512 ears with various middle ear diseases, the middle ear pressure was measured a minimum of 2 years and a maximum of 10 years after tympanoplasty. The findings were related to the length of the follow-up period and to retractions of the drum and/or in the epitympanum. The tympanometric findings were best in sequelae to otitis with dry perforations, poorest in cholesteatomas and adhesive otitis. Tubal function had not further deteriorated 4 years after the operation. There was a highly significant correlation between the middle ear pressure and the frequency of retractions, which also does not essentially increase--except in the cholesteatoma cases.

Acoustic Impedance Tests↗

The influence of endotoxin upon middle ear fibroblasts cultured in normal middle ear gas and atmospheric air.

Otitis media represents a continuum of inflammatory stages frequently in association with bacteria and/or endotoxin. Furthermore, the disease is often treated with insertion of ventilation tubes, which causes hyperoxia relative to the physiological state in the tympanic cavity. The present study was undertaken to quantitate the interaction between endotoxin and relative hyperoxia in cultures of rabbit middle ear fibroblasts incubated in normal middle ear gas and atmospheric air, respectively. Growth was monitored by determination of DNA, cell protein and cell division. The synthetic activity was estimated by collagen production. The antioxidant defense was determined by measuring the intra-and extracellular concentrations of superoxide dismutase (SOD). The results demonstrated that hyperoxia significantly impaired the growth of middle ear fibroblasts, which was compensated for by addition of endotoxin stimulating the growth. The collagen synthesis increased significantly in atmospheric air with a synergistic effect of endotoxin. Hyperoxia induced intracellular SOD formation, while endotoxin tended to reduce the synthesis. Finally, exposure to atmospheric air caused significantly larger amounts of reducing agents extracellularly in cultures without endotoxin compared to endotoxin incubated cultures. It is suggested that endotoxin possess both synergistic and antagonistic potential as regards the effects of relative hyperoxia, and that the interaction between endotoxin and hyperoxia may be an important factor in otitis media.

Animals↗

[Measuring vibration properties of middle ear implants with the mechanical middle ear model. Initial results].

With the aid of a mechanical middle ear model (MMM) the sound transmission properties of different middle ear implants were investigated. Input of the MMM involved a broad-band signal from 100 to 5000 Hz that was supplied by a miniaturized loudspeaker. Displacement of an artificial stapes footplate was measured by a fiberoptic probe. The transfer functions of four different total ossicular replacement prostheses (TORPs) of different materials and shapes were compared. Three of the devices revealed similar transfer functions which corresponded to the typical curve of the normal middle ear. One of the prostheses demonstrated a high-frequency deterioration of approximately 5 dB. This effect was explained by a 3- to 6-times higher mass of the implant when compared to the others. Altogether, the weight of the prosthesis seems to have the most marked impact on sound transmission to the inner ear, whereas stiffness of the implant itself is less crucial as long as it can be regarded as a rigid body.

Acoustic Impedance Tests↗

[Inner ear depression after middle ear interventions].

BACKGROUND: Any type of otosurgical procedure involves the risk of inner ear damage. As middle ear surgery is also performed for functional reasons this risk should be taken into consideration. The aim of this study was to analyse the frequency and the nature of sensorineural hearing loss following chronic ear surgery. PATIENTS: A total of 3989 middle ear cases operated on between 1991 and February 1999 at the Department of Otorhinolaryngology, Head and Neck Surgery, University of Würzburg, Germany were studied retrospectively: 781 type I tympanoplasties, 2408 type III tympanoplasties and 800 cases of stapes surgery. The pre- and the postoperative audiograms in the frequency range between 500 and 8000 Hz were analysed and correlated to the different intraoperative findings. RESULTS: Sensorineural hearing loss occurred in a total of 1.3% of 2224 patients with normal preoperative bone conduction thresholds: 0.2% became deaf, 0.8% acquired a high tone loss at 4 kHz and in 0.3% patients also 2 kHz was affected. None of the documented intraoperative complications such as bleeding, unexpected opening of a semicircular canal, extensive manipulation at the ossicular chain or a gusher phenoma showed a relevant effect on postoperative bone conduction thresholds. The incidence of high tone loss was not increased in cases of extensive drilling of the temporal bone. An unexpected opening of the vestibulum led to a small, but statistically significant change in postoperative bone conduction thresholds. CONCLUSIONS: Our results demonstrated that the risk for sensorineural hearing loss caused by middle ear surgery is low. None of the analysed factors seems to be a relevant prognostic risk factor for postoperative inner ear depression.

Adolescent↗

The influence of anterior nasal packings on middle ear pressure.

In 27 patients, representing 53 ears, middle ear pressure was measured before and after septoplasty/rhinoplasty. On the fourth postoperative day there was no demonstrable statistical difference (Mann-Whitney test). The various possible reasons for postoperative tube occlusion are discussed, mucosa oedema being considered the most important reason.

Adolescent↗

Middle ear status at myringotomy and its relationship to middle ear immitance measurements.

Middle ear status at myringotomy was compared to middle ear immitance measurements in 76 ears. Clinical features examined included plane and mobility of the tympanic membrane, amount of effusion, and status of the middle ear mucosa. Middle ear effusion yielded the strongest relationship with immitance results. Plane and mobility of the tympanic membrane were not strongly related with clinical immitance data. Tympanometry and acoustic reflex threshold were found to be the best indicators of the presence of middle ear effusion.

Acoustic Impedance Tests↗

Measures of middle ear admittance during experimentally induced changes in middle ear volume in the hamster.

The relation between middle ear admittance measured at the tympanic membrane and middle ear volume was studied in adult hamsters. A modified tympanometric procedure was used to measure complex admittance at eight test frequencies. Middle ear volume was varied by injecting small amounts of water into the bulla cavity. As bulla volume decreased, the value of admittance magnitude also decreased. The measured values of admittance magnitude could be accurately predicted by the equation for admittance magnitude until the bulla was about 70% filled. The results confirm that measures of middle ear admittance reflect the volume of the middle ear cavity as would be expected of a pure compliance. Where such measures are available in man, they might be used to predict the degree of fluid intrusion into the middle ear cavity.

Acoustic Impedance Tests↗

[Study on middle ear ventilation using positional tympanometry--normal ear].

The middle ear is a cavity surrounded by solid bones, lined with mucosa, which has a gas-filled lumen. Cavernous organs such as the ear should have their own ventilation system under atmospheric pressure. The mechanism of ventilation in the middle ear has not been sufficiently clarified. Ventilation performed in the middle ear may be classified into two types: 1) passive ventilation via the Eustachian tube, required in cases of abnormal pressure and 2) unique physiological active ventilation of the middle ear performed under atmospheric pressure and not involving the Eustachian tube. The purpose of the present study is to prove the existence of this active ventilation under atmospheric pressure. The subjects were 50 normal ears and elevation of middle ear pressure in the lateral position (determined by positional tympanometry) was studied. The change in the peak level, on tympanometry, was used as an index. The results were continuously recorded every 12 seconds. The following results were obtained. 1. Middle ear pressure was elevated by changing from the sitting to the lateral position. Venous pressure was regarded as a causative factor in this pressure elevation. 2. The elevated middle ear pressure in the lateral position suggested gas production from mastoid cells of the middle ear. The observation that the middle ear pressure was stabilized with the increase in pressure, up to a level of 85-90 mm H2O, indicated the existence of gas leakage from the Eustachian tube and a mechanism for controlling gas production from the mastoid cells of the middle ear.

Acoustic Impedance Tests↗

[Study on middle ear ventilation using positional tympanometry--post mastoidectomy ear].

The middle ear is a cavity surrounded by solid bone, lined with mucosa with a lumen filled with gas. To examine this unique ventilation system under atmospheric pressure, the middle ear pressure of 50 normal ears was previously examined. Positional tympanometry, whereby the middle ear pressure is increased as the subject assumes the lateral position under atmospheric pressure was used. As a result, (1) The middle ear pressure was elevated by the change from the sitting position to the lateral position. Venous pressure was regarded as causative factor of this pressure elevation. (2) The elevation of the middle ear pressure in the lateral position suggested gas production from the mastoid cells of the middle ear. In this study, a proportion of the mastoid cells were removed to resect a tumor of the internal acoustic meatus in conjunction with resection of an acoustic tumor. After resection the area was filled with fascia and fatty tissue. The middle ear pressure of each subject was monitored to determine the effect of a decrease in the mastoid cell volume on middle ear pressure. The results were continuously recorded every 12 seconds for the lower ear when the subjects were in the lateral position. The following results were obtained. (1) The elevation of the middle ear pressure due to positional change among subjects which had had acoustic tumors resected was noticeably greater than the elevation in normal ears. This is thought to have been the result of an elevation in cerebrospinal fluid pressure attributable to positional change, along with an elevation in intravenous pressure. (2) We made comparisons of increases in middle ear pressure 10 minutes after assuming the lateral position in 14 ears after acoustic tumor resection and in 21 normal ears. No noticeable differences were found in the middle ear pressure increases between the two groups despite the fact that the volume of the mastoid cells in the group that had tumors resected had been greatly reduced.

Acoustic Impedance Tests↗

Using high resolution computed tomography to evaluate middle ear cleft aeration of postoperative cholesteatoma ears.

BACKGROUND: Middle ear cleft mucosa and mastoid air cells are important for middle ear cleft aeration. However, the postoperative cholesteatoma ears treated in traditional open or closed techniques are often complicated by an atelectatic condition. In order to preserve the healthy mastoid air cells and also eradicate the cholesteatoma completely, we treated cholesteatoma ears by "tailored mastoidectomy with cartilage obliteration of the open cavity." METHODS: We used high resolution computed tomography (HRCT) to evaluate middle ear cleft aeration of postoperative cholesteatoma ears. Statistical analysis were used to investigate the correlation between postoperative milddle ear cleft aeration and associated clinical factors such as middle ear mucosa condition found intraoperatively (intact or defective), stage of cholesteatoma, level of mastoid pneumatization, range of cartilage obliteration, and tympanoplasty type. RESULTS: Forty-four cholesteatoma ears of forty-three patients (aged 13 to 74 years) underwent tailored mastoidectomy with cartilage obliteration of the open cavity from 1988 to 1998. Aeration of the middle ear cleft was evaluated using HRCT performed in a mean of 6.77 years after surgery. There was no aeration in 10 ears (22.7%), aeration only in the tympanic cavity in 19 ears (43.2%), and aeration in both the tympanic and mastoid cavities in 15 ears (34.1%). There were 26 ears (59.1%) with intact and healthy mucosa and 18 ears (40.9%) with defective mucosa. The correlation between the mucosal condition and recovery of middle ear cleft aeration was significant (r = 0.6855, p < 0.001). Recovery of aeration was negatively correlated with the stage of cholesteatoma (r = -0.4951, p = 0.0156) and positively correlated with the level of postoperative mastoid pneumatization (r = 0.8036, p < 0.001). CONCLUSIONS: Preserving healthy middle ear cleft mucosa and uninvolved mastoid air cells during cholesteatoma surgery enables gas-exchange through the remaining mucosa and maintains the pressure buffering effect of the mastoid, both of which are important for recovery of middle ear cleft aeration. HRCT is useful for the postoperative evaluation of middle ear cleft aeration.

Adolescent↗