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At least 145 records · Page 8Linked to original sources
PubMed1976

Tissue reaction to middle ear prostheses: in vivo observation (rabbit ear lobe) of polyethylene tube, stainless steel wire and absorbable gelatin sponge used in middle ear surgery.

Over the past ten years, polyethylene tube, stainless steel wire and absorbable gelatin sponge have come to be used in middle ear surgery. A modified Williams' steel chamber with a transparent central area was embedded in a rabbit ear lobe surgically, and cross-sectioned polyethylene tube, stainless steel wire or absorbable gelatin sponge were inserted respectively. The in vivo tissue reaction to each of these installed materials was observed daily microscopically. Finally, in the case of both the cross-sectioned polyethylene tube and the stainless steel wire, the chambers were fixed with 10% formalin solution and the contents stained for histological study. The results were as follows: Absorbable gelatin sponge was absorbed completely by phagocytosis in 62 days. Polyethylene tube was encapsulated by a layer of fibroblasts by day 110 in one case and by day 140 in another case; these findings were confirmed histologically on day 110 and 281. Almost all the surface of the stainless steel wire was encapsulated by a layer consisting of giant cells, on which a dense fibrous layer was superimposed by day 82. It is concluded that polyethylene tube, stainless steel wire, and absorbable gelatin sponge should be well tolerated in middle ear surgery.

Absorption↗
PubMedDate not supplied

Cholesteatoma in children: histopathologic findings in middle ear ossicles.

Middle ear ossicles removed during ear surgery in 40 patients were examined in order to compare the histopathologic changes in children with those observed in adults. Bone resorption, mainly localized at the level of the periosteum and haversian canals in adults, was much more extensive in children. Replacement of bone by fibrous granulation tissue was observed in 60% of children's ossicles and in 27% of those belonging to adults. In children, extensive active resorptive osteitis of the ossicles was frequently associated with intensive round cell infiltration, which seems to play an important role in bone absorption and in the aggressiveness of cholesteatoma.

Adolescent↗
PubMed1997

Enhanced epithelial proliferation due to elevated levels of interleukin-1 receptors in middle ear cholesteatomas.

Middle ear cholesteatoma epithelium is a rich source of interleukin-1-alpha (IL-1-alpha), being involved in both keratinocyte hyperproliferation and bone destruction. IL-1-alpha exerts its effects by binding to two distinct IL-1 receptors (IL-1-R). In this study, we have examined the expression of IL-1-R type II (IL-1-R-II) in cholesteatoma samples and have quantified these levels with computer-assisted image analysis. Normal aural skin was used as control. Immunostaining demonstrated the presence of IL-1-R-II in both epidermis and cholesteatoma keratinocytes. The receptors were 3 times higher than those in normal epidermis. The presence of IL-1-alpha in cholesteatoma epithelium coupled with the induced expression of IL-1-R-II indicates the existence of a highly regulated system of autocrine stimulation of cholesteatoma keratinocytes by IL-1.

Cell Division↗
PubMed1988

The mechanics of the middle-ear at static air pressures: the role of the ossicular joints, the function of the middle-ear muscles and the behaviour of stapedial prostheses.

In an experimental study, the mechanical behaviour of the ossicle-chain during changes of the static air pressure was analyzed microscopically and with a radiographic magnification technique in temporal bone preparations. Several preliminary experiments served to pinpoint methodological problems, like exsiccation-artifacts, storage procedures, preparation defects, missing air-cushion effect with the opened middle-ear cavity, absent labyrinthine pressure, relation of the optical axis to middle-ear structures and statistical reproducibility of the measured values. Variations of the static air pressure in the external ear canal ranging from 0 to +/- 400 mmH2O induce an inward-outward movement of the malleus. In the regular middle-ear, the direction of this movement is changed within the ossicular chain into a predominantly upward-downward direction of the lenticular process, due to a gliding function of the incudo-malleal (IM) joint. This results in a gliding movement of the surfaces of the incudostapedial joint (IS). In this way, the stapes and the inner-ear are decoupled from the excessive displacements of the drum membrane and malleus. This change in the mode of motion explains many former results of ossicle vibration, aroused by unphysiologically high sound pressures, like v. Békésy's description of the tilting footplate. This mode of motion, however, changes completely if the gliding function of the IM-joint is cancelled by experimental ankylosis. In that case, the predominant direction of movement at the incus and stapes is inward and outward, too. This mode of motion has been the generally accepted concept of the ossicle-chain mechanics up to now. This isodirectional motion also occurs with progressive exsiccation of the temporal bone preparations, explicable with drying and shrinking of the capsular ligament of the IM-joint. It is conceivable, therefore, that our concepts of the mechanics of the ossicle-chain were partly based on experiments with insufficiently moistened temporal bone preparations, as the methodological problem of the exsiccation became known only during recent decades. In further experiments with static air pressure, the mechanics of the reconstructed ossicle-chain, i.e. tympanoplasty and stapedial prostheses, were studied. In the columella-like chain reconstruction, the displacement of the stapes equals the values measured with the ankylosed IM-joint. This displacement is limited by the strength of the annular ligament, whose function, however, is eliminated in the case of stapedial prostheses. Now the displacement is limited by the friction of the piston at the perforation in the footplate.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1989

Meconium contamination of the neonatal middle ear.

The neonatal middle ear and mastoid cavity are frequently contaminated by cells and hair of the amniotic fluid. This amniotic fluid cellular content provokes a foreign body inflammatory reaction that can persist for months. To evaluate whether clinical and postmortem findings might correlate with the amount of amniotic fluid cellular content in the middle ear, we compared temporal bones of nine patients born through meconium-contaminated amniotic fluid with those of 10 patients born through clear amniotic fluid. All patients were examined at less than 17 days postpartum and provided 37 temporal bones for histologic analysis. The volume of contaminant was quantified for each patient. The cases were arranged according to volume of contaminant in the middle ear and compared with clinical information and autopsy findings. Patients with larger volumes of contaminant in the middle ear were born through thick, meconium-stained amniotic fluid (1.9-38 mm3; average 9.3 mm3). Conversely, patients with lesser volumes of contaminant in the middle ear were born through unstained amniotic fluid (none to 3.2 mm3; average 0.9 mm3). We speculate that patients born through thick, meconium-stained amniotic fluid may be at greater risk of sequelae such as otitis media from this foreign body inflammatory reaction in the middle ear and mastoid cavity.

Amniotic Fluid↗
PubMed2003

Tympanometry versus direct middle ear pressure measurement in an artificial model: is tympanometry an accurate method to measure middle ear pressure?

HYPOTHESIS: Indirect tympanometric pressure measurements of the middle ear (ME) do not correspond to direct pressure measurements. BACKGROUND: Tympanometry is an accepted method for estimating ME pressures. These pressure values are different, however, when measurements are made directly. MATERIALS AND METHODS: Negative pressures were induced by volume changes in an artificial ME model with various "mastoid" volumes. Both tympanometric and direct pressure measurements were obtained simultaneously. RESULTS: A substantial difference was demonstrated between tympanometric and direct pressure measurements. There was a linear correlation between tympanometry and direct pressures between -46.8 and -93.6 mmH2O, with a tympanometric overestimation of 40% to 20%, respectively. The smaller the "mastoid" volume, the greater the overestimation. The correlation was not linear for direct pressures between zero and -46.8 mmH2O. Tympanometric overestimation was greatest (i.e., 4-14-times the actual pressure) in the pressure range between zero and -12 mmH2O. CONCLUSIONS: Tympanometry does not yield precise ME pressure values. In a model with a larger "mastoid" and an actual pressure range of -46.8 to -93.6 mmH2O tympanometric readings are somewhat less unreliable (error of 40%-20%). However, tympanometry is in error of more than 400% in a model with a small mastoid in which the actual ME pressure is only slightly negative (i.e., range between -3.9 and -46.8 mmH2O). Therefore, this study implies that tympanometry has little use for measuring ME pressure especially in chronic ears or their sequelae that are usually characterized by having small negative pressures and small mastoids.

Acoustic Impedance Tests↗
PubMed1999

Bilateral middle ear squamous cell carcinoma and clinical review of an additional 5 cases of middle ear carcinomas.

We reported a retrospective review of the clinical records for a 64 year old male patient with bilateral middle ear squamous cell carcinoma (MESCC), and for the five other patients with MESCC treated at our institution during the last 20 years. The patient with bilateral MESCC has survived and remained tumor free for more than 1.5 years after extended radical resection of the secondary tumor combined with intra-arterial and systemic chemotherapy, radiotherapy and immunotherapy. Four patients with unilateral MESCC were treated with multidisciplinary treatment (induction chemotherapy, surgery and radiotherapy), and the remaining patient was treated with radiotherapy and mastoidectomy. Five of the six patients are alive with no evidence of disease. The patient treated with radiotherapy and radical mastoidectomy died of local recurrence 3 years after diagnosis. We suggest that MESCC should be considered when refractory granulation, long-standing otorrhea, otalgia and facial paralysis are observed. Multidisciplinary treatment, including intra-arterial chemotherapy and en bloc resection of the temporal tumor is useful for the treatment of MESCC and will improve the prognosis of patients with this disease.

Adult↗
PubMed1999

Oxygen modulates Na+ absorption in middle ear epithelium.

The physiology of the middle ear is primarily concerned with keeping the cavities air filled and fluid free to allow transmission of the sound vibrations from the eardrum to the inner ear. Middle ear epithelial cells are thought to play a key role in this process, since they actively transport Na+ and water. The PO2 of the middle ear cavities varies from 44 to 54 mmHg in healthy human ears but may be lower in the course of secretory otitis media. The effect of chronic hypoxia on ion transport was investigated on a middle ear cell line using the short-circuit current technique. Chronic hypoxia reversibly decreased the rate of Na+ absorption across the MESV cell line. Although a decrease in cellular ATP content was observed, the decrease of Na+ absorption seemed related to a primary modulation of apical Na+ entry. As revealed by RNase protection assay, the decrease in the rate of apical Na+ entry strictly paralleled the decrease in the expression of transcripts encoding the alpha-subunit of the epithelial Na+ channel. This effect of oxygen on Na+ absorption might account for 1) the presence of fluid in the middle ear in the course of secretory otitis media and 2) the beneficial effect of the ventilation tube in treating otitis media that allows the PO2 to rise and restores the fluid clearance.

Absorption↗
PubMed1998

A randomized prospective trial to compare four different ear packs following permeatal middle ear surgery.

Surgeons choice of an ear pack is dictated by availability, previous training and personal preference. There has been no recent prospective study evaluating the use of different types of ear packs. This randomized prospective study compares the use of BIPP impregnated ribbon gauze (Aurum), Pope wicks (Xomed-Teace), silastic sheeting (Dow Corning) and tri-adcortyl ointment (Squibb) as an ear dressing following 'clear' middle ear procedures via a permeatal approach. The results showed that there was no statistically significant difference in post-operative pain and discomfort experienced, neither was there any significant difference regarding the otolaryngologist's assessment of the degree of canal granulation, stenosis or discharge with the above named packs. This study concludes that non-traditional dressings such as tri-adcortyl ointment or simply a thin silastic sheet placed on the drum are no worse than time honoured BIPP. They have, as well, the advantage of being well-tolerated by the patients.

Bandages↗
PubMed2001

Medium-term middle ear ventilation with self-manufactured polyethylene T-tubes for the treatment of children with middle ear effusion.

We present the results of the insertion of self-made polyethylene T-tubes for a period of 15-24 months for the treatment of chronic middle-ear effusion. We compare the outcome of our patients to the reported outcome of patients treated with other commonly used ventilation tubes for either shorter or longer periods of time. In a retrospective review of 603 T-tubes inserted in 306 children up to the age of 12 years, charts were reviewed for age, sex, surgical procedure performed, duration of ventilation and complications. In all cases the indication for surgery was chronic middle-ear effusion. The tubes were electively removed by the authors after 15-24 months of ventilation. Spontaneous extrusion was considered a complication. The mean period of ventilation was 20 months. Post-operative otorrhoea was experienced in 6.6 per cent of ears; 4.8 per cent of tubes extruded spontaneously, whereas 3.15 per cent had to be removed earlier than originally planned; 4.9 per cent of ears were re-ventilated at a later date, and 1.49 per cent of ears developed a persistent perforation. We demonstrate that the outcome of patients treated with our self-manufactured tubes for a period of 15-24 months is, in many respects, better or at least comparable to the reported outcome of patients treated with other commonly used ventilation tubes for either shorter or longer periods of time, and that the many complications associated with the conventional T-tube can be reduced. We suggest that our favourable outcome may be due to the duration of ventilation, which was controlled to be shorter than the conventional long-term T-tubes and longer than that of grommets.

Child↗