ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveTo assess the chemical composition of cerumen by flash pyrolysis-gas chromatography/mass spectrometry.Study DesignCollected earwax specimens were fractionated into residue and supernatant by means of deoxycholate. This natural bile acid produces significantly better disintegration of earwax in vitro than do presently available ceruminolytic preparations, and also has demonstrated excellent clinical results in vivo to date.PatientsThe sample for analysis was obtained from a patient with clinical earwax impaction.ResultsThe supernatant is composed of simple aromatic hydrocarbons, C5-C17 straight-chain hydrocarbons, a complex mixture of compounds tentatively identified as diterpenoids, and steroids, in particular cholesterol. The residue, on the other hand, produced simple aromatic compounds (including benzenes, phenols, and benzonitriles), C5-C25 straight-chain hydrocarbons, greater relative quantities of nitrogen compounds and phenol, and lesser importance of the (tentatively identified) diterpenoids.ConclusionsThrough the use of the detergent deoxycholate, squalene and a tentatively identified diterpenoid were revealed to be present in a free, unbound state, whereas some steroids and hydrocarbons appeared to be bound to a macromolecular structure by nitrogen linkages or other bonds. Additionally, this study reintroduces detergents as a viable method of earwax removal, specifically the bile acids.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveThe aim of this study was to understand the historical development of the knowledge of cholesteatoma.Materials and MethodsReview of the literature from 1683 to 1999 concerning the date-related knowledge of cholesteatoma.ResultsIn 1683, Duverney first described a temporal bone tumor probably corresponding to a cholesteatoma. Until 1838, when Müller coined the termcholesteatoma, nothing new about this condition appeared in medical publications. After 1838, three main theories about the pathogenesis of cholesteatoma were published. Virchow, in 1855, considered cholesteatoma to be a tumor arising from the metaplasia of mesenchymal cells to epidermal cells, growing then as tumoral cells. Gruber, Wendt, and von Troeltsch, in 1868, considered cholesteatoma to be the result of a metaplasia not of bone cells but of tympanic mucosa cells into a malpighian epithelium. Politzer, in 1869, assumed that cholesteatoma was a glandular neoplasm of middle ear mucosa. Bezold and Habermann, in 1889, considered cholesteatoma to be the result of migration of the external ear canal epidermis into the tympanic cavity via a marginal perforation after acute or chronic otitis. It took 40 years of discussions about these three theories to finally confirm that Habermann and Bezold were correct.ConclusionThe knowledge of cholesteatoma has evolved with other medical branches. As otologists began to monitor their patients in vivo, not limiting their observations to temporal bone dissections, the genesis of cholesteatoma became well understood. Today, with immunology and new histopathologic techniques, it is anticipated that we will learn much more about cholesteatoma.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

HypothesisThis study was conducted to evaluate the use of Grafton human demineralized bone matrix as a graft material for mastoid cavity obliteration and canal wall reconstruction in an animal model.BackgroundCanal wall down procedures in the treatment of cholesteatoma may result in a problematic mastoid cavity. Elimination of the mastoid cavity by obliteration or canal wall reconstruction can prevent or correct this problem. Many techniques and implant materials have been used for this application, yet no single material has proven to be ideal.MethodsAthymic rats received tympanic bulla obliteration and lateral bulla wall reconstruction utilizing the Grafton Putty and Flex formulations, respectively. Wound healing was monitored twice a week. Auditory brainstem evoked responses were obtained 8 weeks after implantation. Nine weeks after implantation, the animals were killed, and histologic sections were prepared. A histologic bone formation score (range 0–4) was determined for each implant.ResultsWound healing occurred without complication. Auditory brainstem response thresholds (average 23.5) fell within the normal range for all ears tested. The average histologic bone formation score for all implants was 3.7. The average scores for obliteration implants and wall reconstruction implants were 3.5 and 3.9, respectively. All wall reconstruction implants underwent partial or total collapse into the bulla.ConclusionsThe high level of bone formation obtained by the use of Grafton implants in this study makes this material a promising resource for use in mastoid obliteration. The use of the material for canal wall reconstruction will likely require a sturdier preparation to prevent collapse into the mastoid cavity.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

HypothesisUnilateral conductive hearing loss (HL) causes measurable disability in realistic hearing environments. The benefits of improving this loss depend both on the absolute level of final hearing and on hearing asymmetry.BackgroundSurgical success is often measured by the degree of change in the air-bone gap or in the air thresholds. The Glasgow Benefit Plot and the Belfast Rule of Thumb suggest that a given hearing gain will be of greater benefit if the postoperative thresholds in the worse ear are a <30-dB HL or within 15 dB of the contralateral ear. This assertion has important surgical implications, but few audiometric data supporting it currently exist.MethodsSpeech-in-noise sound-field scores were measured in 16 normal volunteers at three presentation levels at two signal-to-noise ratios (SNRs). Two levels of unilateral conductive HL were simulated with earplugs, averaging 25-and 43-dB HL, respectively, and the effect on speech-in-noise scores was measured and analyzed.ResultsUnilateral conductive HL is a disadvantage at lower sound intensities and low SNRs, but it can be compensated for by increasing volume or SNR. The benefits of improving unilateral conductive HL are greater if the final asymmetry is <25 dB and the final hearing threshold is <25 dB.ConclusionsUnilateral conductive HL is a significant disadvantage at low SNRs or presentation volumes. The benefits of surgery to improve HL depend not only on the degree of hearing improvement but also on the final hearing threshold in both ears.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveEvaluation of suitability of flexible composite sheets (hydroxylapatite and polymer) for outer ear canal (OEC) wall reconstruction in tympanoplasty.Study DesignProspective, open label pilot study.SettingUniversity and regional hospital.PatientsForty-two randomly selected patients with chronic otitis media (n = 20) and cholesteatoma (n = 22) among 356 patients admitted between 1996 and 1997.InterventionsEradication of disease through a partial or total canal wall down mastoidectomy; immediate reconstruction of canal wall with flexible composite sheet (hydroxylapatite and polymer) and connective tissue graft.Outcome MeasuresAnatomic integrity of the OEC and neotympanum, extrusion rate, complications.ResultsAt minimum follow-up of 24 months: recurrent cholesteatoma (n = 0), residual cholesteatoma (n = 3/22) (13.6%) in the mesotympanum (none behind the hydroxylapatite sheet or in the attic or antrum). The neotympanum was intact in 38 ears (90.4%), reperforated in 2, and severely retracted and lateralized in 1, respectively. Anatomic integrity of the OEC was obtained in 37 (88%) of 42 patients; stenosis or membranous synechiae were observed in 5 ears and treated in the office. Extrusion of the hydroxylapatite sheet occurred in 7 patients (16.6%) because of purulent otorrhea and granulation tissue formation. Surgical revision achieved complete epithelialization of the rebuilt canal wall in 33 ears (78.6%).ConclusionsA dry, disease-free ear and normal anatomy may be expected 2 years postoperatively in more than three-fourths of the patients treated using the described surgical technique. Complete protection with a connective tissue graft is essential to avoid extrusion of the implant. The failure rate is significantly higher if otorrhea is present at the time of the operation.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveTo determine the importance of supratubal recess in cholesteatoma surgery by presenting the clinical presentation, imaging findings, and surgical treatment methods of 66 patients with cholesteatoma. We propose that the management of supratubal recess allows the opportunity for total removal of the cholesteatoma with the prevention of recurrence.Study DesignRetrospective review of surgical cases.SettingTertiary referral center.InterventionsDiagnostic and therapeutic procedures were performed.Patients and MethodsWe present a series of patients with involvement of supratubal recess by reviewing the operative charts of 347 patients surgically treated for aural cholesteatoma between 1990 and 1999.ResultsWe detected the involvement of supratubal recess in 19% (n = 66) of our operations for aural cholesteatoma removal.ConclusionThe intent of this study is to improve the chance for a successful outcome by decreasing the rate of recurrence. The surgical approach to supratubal recess in cholesteatoma operations is emphasized with our series.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveWe previously described the use of anterior subannular T-tubes (n = 20) for long-term middle ear ventilation. In the current study, we examine a larger patient population (n = 38) and a longer follow-up interval (average >2 years) to evaluate the efficacy and safety of anterior subannular tympanostomy.Study DesignRetrospective nonrandomized case review.SettingTertiary referral hospital.PatientsOur series consisted of 38 consecutive patients with a diagnosis of eustachian tube dysfunction, adhesive otitis media, or chronic otitis media with a perforation who underwent a tympanoplasty.InterventionA subannular T-tube was placed anteriorly at the time of tympanoplasty to provide long-term middle ear ventilation.Main Outcome MeasuresThe main outcomes of this study are tube position, tube patency, and middle ear ventilation. In addition, hearing was evaluated both preoperatively and postoperatively and any complications were noted.ResultsThere were 38 patients and 38 ears that received an anterior subannular T-tube at the time of tympanoplasty. The study group consisted of 24 female patients and 14 male patents with a median age of 36 years (range, 10–75 yr). All 38 patients had eustachian tube dysfunction, 22 had adhesive otitis media, 23 had chronic otitis media, 13 had a cholesteatoma, 11 had tympanic membrane perforations, and 3 patients had a cleft palate. All patients underwent tympanoplasty. Eighteen patients had a concomitant ossiculoplasty and 7 had a mastoidectomy. Follow-up ranged from 1 month to 48 months (average, 26 mo). Three tubes had extruded within 2 years, in 1 case resulting in a persistent perforation. Postoperative complications included 1 patient with a partially extruded prosthesis, 2 patients with tipped prosthesis and persistent tympanic membrane retraction, and 1 patient with a plugged tube. All other tubes were patent and showed no evidence of migration. Furthermore, there were no cases of anterior canal blunting or ingrowth of epithelium around the tube.ConclusionAnterior subannular tympanostomy is a safe and effective method for long-term middle ear ventilation in patients with chronic eustachian tube dysfunction.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundThere is some evidence for an inflammatory process as a driving force in otosclerosis. Two popular hypotheses for the induction of this chronic inflammation have been proposed: an autoimmune phenomenon induced by an otic capsule specific antigen and measles virus infection.MethodsAntibodies against measles virus hemagglutinin, polymerase, nucleocapsid, and matrix proteins were evaluated in sera from otosclerotic patients and in sera from healthy age-and sex-matched controls by use of the Western blot analyses.ResultsSignificant differences were not detected between healthy men and women or between otosclerotic men and women. There were significantly stronger reactions against all viral proteins in the group of healthy women as compared with otosclerotic women despite a high standard deviation. The group of healthy male blood donors demonstrated significantly stronger reactions against polymerase and nucleocapsid proteins. Healthy blood donors again demonstrated stronger reaction compared with respective otosclerotic patients in a separate reaction for viral matrix protein.ConclusionOur observation is consistent with viral participation in otosclerotic pathogenesis, but it is difficult to say if the diminished antimeasles humoral response is a consequence or the cause for a local measles infection. In light of the present data, we can discuss autoantibodies in otosclerosis as a sign of autoimmunity triggered by measles virus.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

HypothesisLarge osteoclast-like cells, labeled by using monoclonal antibodies directed against macrophages, are participating in a bone remodeling process in the rat bullar bone after induced experimental acute otitis media, leading to tympanosclerosis.BackgroundIn humans, tympanosclerosis is a sequale of chronic otitis media. It causes hearing disability, especially if the ossicles or the inner ear are affected. No successful treatment is available. To evaluate the inflammatory stages that may lead to tympanosclerosis, the current study was performed.MethodsSprague-Dawley rats were exposed to a pneumococcus Type 3 solution into the middle ear. The rats were killed at 3, 6, and 10 days after inoculation. Sections from the ear specimen were stained immunohistochemically. Antibodies used were directed against macrophages.ResultsPositive cells were seen in the tympanic membrane, in the middle ear mucosa, and close to the tympanic membrane insertion into the bone. Macrophages appeared to be linearized adjacent to the bullar bone, both on the inner and on the outer bullar wall. These cells had the appearance of osteoclasts.ConclusionA differentiation of macrophages to osteoclasts is possible during induced otitis media in the rat, initiating a bone-remodeling process leading to tympanosclerosis.

ISSN:1531-7129    

出版商:OVID    

年代:2001

数据来源: OVID