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PubMed2003

Lateralization of the tympanic membrane as a complication of canal wall down tympanoplasty: a report of four cases.

OBJECTIVE: To describe the pathophysiology and treatment of the lateralized tympanic membrane that occurs after canal wall down tympanoplasty. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral hospital. PATIENTS: Four patients in whom lateralization of the tympanic membrane developed as a complication of canal wall down tympanoplasty. RESULTS: The patients had undergone middle ear surgery 20 to 34 years before their first visit to the authors. A Bondy operation with soft-wall reconstruction of the ear canal had been performed in three patients and a modified radical mastoidectomy in one patient. They all had severe conductive hearing loss. Common findings were anterior canal sulcus blunting, good tubal function, normal middle ear mucosa, and mobile stapes. At revision surgery, the lateralized tympanic membrane was removed, and the temporalis fascia was grafted medial to the malleus manubrium. The exposed bony surface in the ear canal was covered with a split-thickness skin graft, and the ear canal and the mastoid cavity were tightly packed to secure the graft. All the patients regained good hearing after the revision. Although deterioration of the anterior tympanic ring was presumed to be the primary cause of the graft lateralization, the lack of a posterior bony ear canal might have facilitated this condition. CONCLUSION: Lateralization of the tympanic membrane can occur even in an ear with a radicalized mastoid cavity, especially when the anterior tympanic ring is torn and the posterior ear canal is reconstructed with soft tissue.

Bone Conduction↗
PubMed1981

Revision stapedectomy: a review of 258 cases.

We reviewed the records of 258 revision stapedectomy operations performed at the Otological Medical Group during an eight year period. Displacement of the prosthesis to the inferior edge of the window was the commonest cause of failure (41%) and occurred predominately in wire-Gelfoam pad cases. An oval window fistula, a short prosthesis or bony closure of the window were causes of failure in 9% each. Incus necrosis was the cause of failure in 5%. Less than 50% of the operations resulted in postoperative conductive deficit of 10 db or less. The results were better than this in incus bypass procedures, in revisions of cases in which a tissue graft was used over the oval window and in revisions of ears initially operated on elsewhere. Severe sensorineural hearing impairment was the result in 7% of the operations and half of these impairments were dead ears. The majority of these adverse results followed a repeat drill out of obliterative otosclerosis or followed reopening of the oval window in patients with a postoperative inner ear problem other than a fistula. We concluded that 1. revision stapedectomy is a less satisfactory procedure than primary stapedectomy; 2. there is rarely an indication for a repeat drill out of obliterative otosclerosis; and 3. the oval window membrane usually should not be disturbed in revision stapedectomy in a patient with inner ear symptoms unless there is a fistula.

Adult↗
PubMed1998

Intratympanic gentamicin treatment for Meniere's disease.

OBJECTIVES: The purpose of this study was to evaluate the safety and efficacy of a modified intratympanic gentamicin technique in patients with intractable unilateral or bilateral Meniere's disease. METHODS: A retrospective review of 25 consecutive patients who underwent gentamicin treatment for Meniere's disease was conducted between 1992 and 1996. Two separate delivery systems were used during this study, with the last 13 subjects undergoing placement of the new system (flanged polyethylene tubing). RESULTS: Follow-up averaged 23 months. Absence of vertigo spells was reported in 88%, and substantial control was achieved in 12%. Four of five patients with bilateral disease achieved complete control. Results for the two delivery systems were not significantly different. Absence of ice-water caloric response was seen in 75% (15 of 20) patients. Clinically significant sensorineural hearing loss occurred in 5 (20%) of 25 ears. Nonserviceable hearing developed in only two (8%) patients. CONCLUSIONS: Our results support the previously reported efficacy and relative safety of gentamicin infusion therapy for intractable Meniere's disease. Polyethylene tubing may be more advantageous than T-tube delivery because of anatomic concerns in certain patients.

Administration, Topical↗
PubMed1982

Tympanic membrane perforation descriptors and hearing levels in otitis media.

The air conduction threshold of hearing was determined at 0.5,1 and 2 kHz by manual audiometry on a consecutive series of young Thai adults with bilateral chronic suppurative otitis media. At the same time, after visual inspection of each tympanic membrane, the perforation was drawn, as faithfully as possible in respect of both shape and relative size, on a 40-mm diagram of a tympanic membrane. A study of the shapes of perforations showed that they could be described as elliptical, reniform or cardioid. For the purposes of calculating the area of a perforation, a reniform perforation was considered to be the result of substracting a smaller ellipse from a larger ellipse, which ellipses were in contact at the point of least curvature. The hearing threshold level was found to be a function of the size of the perforation. A power function best described this relationship. The relationship was such that a total perforation would be associated with a hearing loss of about 60 dB HL over the frequency range 0.5-2 kHz.

Adolescent↗
PubMed2005

Hearing loss after "refractory" secretory otitis media.

CONCLUSIONS: The results indicate that SOM of extreme duration, and maybe also the treatment of SOM, are risk factors for developing permanent hearing loss, both conductive and sensorineural. OBJECTIVE: Fluctuating or persisting hearing loss of varying degrees is known to accompany secretory otitis media (SOM). The aim of this study was to detect possible hearing sequelae in young adults who had suffered from "refractory" SOM during childhood. MATERIAL AND MEDTHODS: A total of 33 subjects (age 16-25 years) with previous SOM that had persisted for a mean of 11 years (range 6-19 years) were retrospectively examined at a mean of 18 years after their first myringotomy or tube insertion and compared to 15 healthy controls. The follow-up included audiometric examinations (pure-tone audiometry, distorted speech and impedance audiometry), otomicroscopy and scrutiny of medical records. RESULTS: The SOM group had poorer hearing at all frequencies with the exception of 1.5 kHz in the range 0.125-16 kHz. Those with the greatest number of myringotomies and tube insertions and those with the longest duration of SOM had significantly poorer hearing at high frequencies (8-16 kHz) than those with fewer tube insertions and a shorter duration of SOM. The SOM group scored lower on distorted speech tests than the controls.

Adolescent↗
PubMed2002

Effects of conductive hearing loss on auditory nerve activity in gerbil.

The goal of this research was to define the effects of conductive hearing loss (CHL) produced by malleus removal (MR) on auditory nerve activity in the absence of acoustic stimulation. Subjects were gerbils in two age groups: 21 days (P21) and 42 days (P42). Ensemble background activity (EBA) of the auditory nerve was measured by spectral analysis of a signal recorded from the round window. The EBA measure was studied following MR in an acute setting in P42 animals, and in chronic experiments either 5 days (P21 and P42 animals) or 3 weeks (P21 animals) after MR. Findings were: (1) an EBA can be reliably measured in the gerbil, and this measure is highly stable over time; (2) the EBA is eliminated by application of tetrodotoxin, confirming the auditory nerve as the source of this measure; (3) MR results in a statistically significant decrease in the magnitude of the EBA in adult animals; and (4) the EBA measure is age-dependent. The EBA was significantly lower in P21 than in P42 animals, and response to MR varied as a function of age. We conclude that CHL decreases 'spontaneous' activity of the auditory nerve in young adult gerbils.

Age Factors↗
PubMed1998

Intact canal wall mastoidectomy with tympanoplasty for cholesteatoma in children.

OBJECTIVE/HYPOTHESIS: Cases of cholesteatoma in pediatric patients were reviewed to determine which factors influence the outcome of surgical treatment. Cholesteatoma is considered a more aggressive disease in children than in adults. The outcomes of intact canal wall (ICW) mastoidectomy and canal wall down (CWD) mastoidectomy were assessed, as comparisons of different surgical technique. STUDY DESIGN: A retrospective analysis of all cases of pediatric cholesteatoma treated at a single institution by the senior author (P.R.L.) over a period of 11 years was conducted. METHODS: Patient information was collected from an otology database, patient records, and audiology files. RESULTS: Sixty-six patients, aged 10 months to 18 years, were treated and followed for an average of 37.7 months (range 12.2 months to 12.5 y). ICW mastoidectomy with tympanoplasty was the primary surgical treatment in 41 patients. Nineteen percent had residual disease at a planned second stage surgery and 22% developed recurrent cholesteatoma for a total recidivism rate of 41%. A SRT of less than 30 dB HL was achieved in 75% of these patients. Seventeen patients underwent CWD mastoidectomy with tympanoplasty initially. Two patients (12%) had residual cholesteatoma found at a planned second state procedure, and no recurrent cholesteatoma was encountered. Seventy-two percent maintained a SRT of less than 30 dB HL. CONCLUSIONS: These results support the continued use of ICW mastoidectomy with tympanoplasty for pediatric cholesteatoma. If planned second stage surgery is necessary, the long-term results of an ear with useful hearing and few problems with chronic medical care are gratifying. For reasons of anatomy or in an only hearing ear, CWD mastoidectomy with tympanoplasty provides a safe ear and good hearing results. Mastoid cavity care must be maintained indefinitely in many cases.

Adolescent↗
PubMed2006

Preservation of conductive hearing in approaches to tumors of the jugular foramen.

OBJECTIVE: Surgical approaches to the jugular foramen, most often used for the resection of glomus jugulare tumors, may include removal of the external auditory canal wall and overclosure of the meatus, resulting in maximal conductive hearing loss. Modifications have been described that maintain hearing by preserving the canal wall at the price of decreased exposure and are, therefore, suitable only for small and favorably located tumors. Our technique for removal and then reconstruction of the canal wall with hydroxyapatite cement allows for complete anterior translocation of the facial nerve as far proximal as the geniculate ganglion, giving uncompromising exposure of even the most extensive tumors, with the potential for preservation of normal hearing. The purpose of this study was to describe and report our experience with this technique. STUDY DESIGN: : Retrospective review. SETTING: Private otology practice. PATIENTS: Between 2000 and 2005, seven patients between the ages of 34 and 77 years were identified who underwent procedures using this technique. INTERVENTION: Surgical management of jugular foramen tumors. MAIN OUTCOME MEASURES: Successful anatomical reconstruction of the external auditory canal and middle ear. Preoperative and postoperative audiograms are compared, and facial nerve function is reported. Complications are discussed. RESULTS: All seven patients had successful reconstruction of the external auditory canal. Complications were minor and did not require additional surgical intervention. Postoperative pure-tone average differed from the preoperative average by a mean of 7.5 dB. Facial nerve function ranged from House-Brackmann Grades I to III when checked at least 7 months after surgery. CONCLUSION: This study reveals that this technique of external auditory canal reconstruction using hydroxyapatite cement allows complete anterior translocation of the facial nerve, while safely and reliably preserving the potential for normal hearing, without any compromise in exposure of the jugular foramen in the setting of an infratemporal fossa approach.

Abdominal Fat↗
PubMed2005

Long-term results of bone-anchored hearing aid recipients who had previously used air-conduction hearing aids.

OBJECTIVE: To study the long-term results (use, care, satisfaction, ear infections, and audiometry) of the application of a bone-anchored hearing aid (BAHA) to patients with conventional indications who had previously used air-conduction hearing aids. DESIGN: Follow-up study (mean duration, 9 years). SETTING: Tertiary referral center. PATIENTS: The study population comprised 27 patients with conductive or mixed hearing loss and who had participated in a previous study (N = 34). Seven could not be included anymore as a result of death, Alzheimer disease, or problems related to the implant. Everyone filled out the questionnaire, and 23 patients underwent audiometric evaluation. MAIN OUTCOME MEASURES: The patients filled out the adapted Nijmegen questionnaire. Aided free-field thresholds were measured as well as scores for speech in noise and in quiet. Results were compared with those obtained in the initial study. RESULTS: All 27 patients were still using their BAHA and appreciated it with regard to speech recognition in quiet, sound comfort, and improvements in ear infections. The audiometric results showed that most patients tested had stable bone-conduction thresholds over the years (after correction for age). Despite the treatment with BAHA, a significant deterioration in the cochlear hearing was observed in the other patients in the ear under study (their best hearing ear). CONCLUSIONS: Positive patient outcome measures emphasized the importance of BAHA application to patients with conventional indications. The audiometric data showed fairly stable cochlear function but not for all patients. This underlines that conservative treatment should be chosen (fitting of bone-conduction devices).

Audiometry↗
PubMedDate not supplied

Electrical properties of compact bone.

Dielectric properties of compact bone tissue have been measured in the wet, i.e., fluid-saturated, state. Comparison of these with other measurements at high relative humidity (RH) shows that the dc conductivity of wet bone is about 100 times larger than that of the high RH sample. Thus, the extrapolation of the high RH results to in vivo situations is not valid. In addition, the results of electrical measurements on dry bone samples cannot be extrapolated to the in vivo state because of the dominance of the fluid-filled pores. The difference in the results for longitudinal, tangential, and radial samples, both in dc resistivity and relaxation time, reflects the difference in connectivity of the pores on bone in these three orientations. Quantitative estimates of the cross-sectional area of connected pores are obtained from measurements on photomicrographs and correlated with dc conductivity of the samples. Further evidence for the dominance of the fluid-filled pores in determining the properties of the tissue comes from the results for bone conductivity g measured as a function of saline conductivity g0. The ratio g/g0 is approximately constant with respect to changes in g0 over a range corresponding to the conductivities of various body fluids. The influence of the dielectric properties in all but destroying the piezoelectrically generated voltage in going from the dry to the wet state is discussed. It is suggested that some mechanism other than the piezoelectric effect (e.g., streaming potentials) must be considered to account for the magnitude and decay time of the electromechanical voltage measured in wet bone. Our studies suggest that fluid transport plays a significant role not only in various aspects of bone metabolism such as mineralization, but also in the electrical, mechanical, and electromechanical properties of bone.

Animals↗
PubMed1993

[Indirect testimony of stress conduction from mandible to skull in maxillofacial trauma: morphological changes of temporomandibular joint disc]

There were cerebral injuries accompanied in maxillofacial high velocity projectile wound.Owing to the special anatomic relationship between skull and facial bones,the stress conduction of bone was an important factor of cerebral injury in maxillofacial wound.In this experiment,the canine mandibular regions were wounded by steel spheres,which weight 1.03g,impacting velocity at 1400m/s,to produce severely maxillofacial firearm wounds.The morphological and pathological changes of temporomandibular joint disc of wounded side were observed with light and electron microscopes.The microscopic injuries of disc,including arrangement disorder of figre,spotty edema and some fibrous dissolution,etc,were found.These results have provided an indirect evidence of injurous mechanism of the cerebral injury accompaning maxillofacial high enery misslle wound.

Journal Article↗