Revision tympanoplasty including anterior perforations and lateralization of grafts.

Not long ago, the restoration of a perforated tympanic membrane by grafting over an air-containing tympanic cavity seemed impossible. Fortunately, successful results are so consistent and universal today that restoration of the tympanic membrane is expected, and a failure calls for careful evaluation as to "why". If known principles are observed, few complications need occur. Usually, complications are the result of either the choice and placement of the graft used in the repair, or the presence of unresolved upper respiratory pathology. When revision tympanoplasty is necessary, use of the underplay fascial graft technique, properly applied, usually can solve any difficult problems.

Biomechanical influences of magnetic resonance imaging on the SOUNDTEC Direct System implant.

OBJECTIVE: The purpose of this study was to measure the forces experienced by the SOUNDTEC Direct System magnetic implant during 0.3-T MRI. STUDY DESIGN: Torsional and linear forces imposed on 8 implants were measured by using calibrated neurologic Von Frey hairs and were compared with finite-element analysis predictions and the forces required to separate the incudostapedial joints of unpreserved temporal bones. An implanted embalmed autopsy specimen was also examined before and after 1.5-T MRI. RESULTS: Peak linear force at the orifice of the MRI core measured 0.51g (+/-0.2 SD). Maximum torque occurred at the MRI core center and measured 11.4g-cm (+/-1.2 SD). The mean torque required to separate the incudostapedial joints of 12 unpreserved temporal bones was 33.8g-cm (+/-20.4 SD). The autopsy specimen sustained a 1.5-T MRI scan without disruption of the ossicular chain or explantation. CONCLUSIONS: Physical and mechanical testing of the SOUNDTEC implant indicates that the structural integrity of the ossicles will be maintained during 0.3-T MRI of the human head.

Middle ear electromagnetic semi-implantable hearing device: results of the phase II SOUNDTEC direct system clinical trial.

OBJECTIVE: To assess the safety and efficacy of the SOUNDTEC Direct System, a partially implantable electromagnetic middle ear hearing device. STUDY DESIGN: Food and Drug Administration Phase II clinical trial of 103 patients at 10 sites across the United States. SETTING: Tertiary referral medical centers. PATIENTS: Individuals with bilateral moderate to moderately severe sensorineural hearing impairment who had worn optimally fit hearing aids for at least 45 days. INTERVENTIONS: Therapeutic intervention included implantation of a 27-mg neodymium iron boron magnet encased in a laser-welded titanium canister onto the incudostapedial joint, followed, after a 10-week healing period, by fitting with a deep earmold coil assembly and activation of the sound processor. MAIN OUTCOME MEASURES: Functional gain, speech recognition in quiet and noise, articulation index scores, perceived aided benefit, sound quality judgments, satisfaction, and presence of feedback and occlusion with the Direct System were compared with those of the patients' optimally fit hearing aid. RESULTS: The results of this multicenter clinical trial were submitted to the Food and Drug Administration on April 13, 2001, and are presented here. The results with the use of the SOUNDTEC Direct System compared with an optimally fit hearing aid provided an average 7.9-dB increase in functional gain in the speech frequencies (500-4,000 Hz) and a 9.6 dB gain in high frequencies (2,000, 3,000, and 4,000 Hz). There was a statistically significant average increase of 5.3% in speech discrimination. The mean speech perception in noise test score was improved, but the improvement was not statistically significant. Subjective tests using abbreviated profile of hearing aid benefit and the Hough Ear Institute Profile demonstrated scores statistically improved over the hearing aid condition. These subjective tests measured areas such as the presence of occlusion and feedback, speech quality judgments, device preference, and perceived aided benefit. CONCLUSIONS: The results of this Phase II clinical trial demonstrate that the SOUNDTEC Direct System provided statistically significant reduction in feedback and occlusive effect as well as a statistically significant improvement in all the following categories: functional gain, articulation index scores, speech discrimination in quiet, perceived aided benefit, patient satisfaction and device preference over the patient's optimally fit hearing aid.

Homograft microlathed femur prosthesis in stapedectomy.

The use of homografts in ossiculoplasty has been well documented in the literature. In the early 1980s, nonossicular homograft otic capsule bone was used as a prosthetic material in stapedectomy. We began using homograft femur as a prosthetic material in the early 1990s. In this article, we report the results of a retrospective study of the use of homograft femur prostheses. A series of 300 stapedectomies was performed between Aug. 24, 1992, and Jan. 20, 2000. Total footplate removal with preservation of the posterior crus was our procedure of choice. However, in 116 of these cases, the posterior crus could not be used, and a homograft femur prosthesis was substituted. For these prostheses, all homograft femurs were obtained from the American Red Cross. All prostheses were prepared in the bone laboratory and stored in the bone bank until needed. After an adequate period of follow-up, we tabulated our results. We found that in 89 of 113 cases (78.8%) available for follow-up, the air-bone gap was completely closed. In addition, the air-bone gap was closed to within 5 dB in 11 patients (9.7%) and closed to within 10 dB in five patients (4.4%). In all, 105 of the 113 homograft femur prosthetic procedures (92.9%) resulted in a successful outcome.

Semi-implantable electromagnetic middle ear hearing device for moderate to severe sensorineural hearing loss.

Despite the many improvements in hearing aid technology, conventional hearing aids continue to have significant limitations, which has led to increased interest in implantable hearing devices. The SOUNDTEC Direct Drive Hearing System for moderate to moderately severe sensorineural hearing loss is one such device. In this article the authors present results on five individuals enrolled in a Food And Drug Administration Phase I feasibility study.

Early clinical results: SOUNDTEC implantable hearing device phase II study.

OBJECTIVE: To assess the safety and efficacy of a new semi-implantable electromagnetic hearing device, the SOUNDTEC Direct Drive Hearing System (DDHS), and to compare its performance with that of subjects' previously worn, optimally fit hearing aids. Preliminary results for the first 10 subjects are presented. STUDY DESIGN: The protocol specified in the Investigational Device Exemption is used in this ongoing FDA phase II 100-subject multicenter clinical trial. METHODS: For baseline, each subject is tested wearing his or her own optimally fit hearing aid in the ear to be implanted. Six-month postoperative outcome measures using the SOUNDTEC DDHS are compared with the baseline. Multiple objective and subjective outcomes (as listed under Results) were measured. RESULTS: When compared with the subjects' optimally fit hearing aids, the SOUNDTEC DDHS provided an average improvement of 52% in functional gain (250-6000 Hz), 22% in aided thresholds, 3.8% for speech discrimination in quiet, 17% for speech in noise, 13.1% in articulation index scores, 28% in aided benefit, 27.3% in sound quality of speech, and a 16.7% increase in overall subject satisfaction. In addition, with the SOUNDTEC DDHS, subjects reported absence of acoustic feedback, little or no occlusive effects, and more natural sound perception. CONCLUSION: Analysis of data on the first 10 subjects using the SOUNDTEC DDHS indicates positive outcomes regarding safety and efficacy, although the small sample size is not sufficient to permit valid statistical inferences to be drawn from our preliminary data. Results also demonstrate improvement in performance compared with the subjects' optimally fit hearing aids and an improvement in quality of life as demonstrated by objective and subjective tests and measures.

Ossiculoplasty.

Homograft human bone is not only the most logical choice for grafting material, but also the closest transplantation material to the host histologically. This article discusses surgical repair of the ossicular chain with homograft bone transplants, including rationale for present surgical techniques, a thorough description of simple methods of microlathing homograft bone grafts, and instructions for maintaining an ossicular replacement bone bank. Furthermore, results in all types of ossiculoplasty and a method of classification of tympanoplasty are presented in this article.

Acute human trial of the floating mass transducer.

Five patients underwent acute implantation of the Floating Mass Transducer (FMT) to evaluate the ability of the FMT to produce measurable auditory thresholds when temporarily placed in the middle ears of patients undergoing routine stapedotomy procedures. The FMT was placed on the long process of the incus in an inferior position, as is planned for clinical application, and in two additional positions. The ability of the FMT to produce measurable auditory thresholds was demonstrated in all patients. Results were affected by the lack of a healing period, the presence of a fixed stapes and an open middle ear space, and patient sedation.

Bone conduction implants for amplification: comparison of results.

We compared the results from the North American patient database on the Xomed Audiant Bone Conductor to those reported on the NobleBiocare (previously Noblepharma) HC200 bone-anchored hearing aid (BAHA) implant, using the literature and specific results provided by one of the authors. It has been proposed that the percutaneous coupling of the NobleBiocare implant transduces energy more powerfully than the Audiant transcutaneous coupling. If true, percutaneous coupling could provide greater amplification, helping patients experiencing both conductive and sensorineural hearing loss. Aided sound-field thresholds corresponding to bone-conduction thresholds were compared retrospectively through the speech frequencies. Both the BAHA and the Audiant devices amplified in the sound field to approximate preoperative bone-conduction thresholds. No statistically significant differences existed between the amplification of warble tones through the speech frequencies for either device. We conclude that amplification with the Audiant device offers as much gain as the HC200 device through the speech frequencies. While both devices can supply effective amplification for select patients suffering from conductive hearing loss, neither provides gain superior to preoperative bone-conduction thresholds to address the needs of select patients with a substantial sensorineural component.

The implantable hearing device for sensorineural hearing impairment. The Hough Ear Institute experience.

This article describes one group's experience in developing and implanting rare earth magnets for conductive hearing loss and also for sensorineural hearing loss. Success and failures from over a decade of work are highlighted.

Selection of biomaterials for middle and inner ear implants.

In the selection of biomaterials for middle ear applications of implantable devices, certainly the site of implantation and the mass of the implant will dictate the choice of biomaterials. Hermetic sealing of an implant is best achieved by the use of metals, not polymers. Osteocompatibility of an ossicular implant can be enhanced by the incorporation of calcium phosphates such as hydroxyapatite coatings. Finally, osseointegration or osseofixation is neither necessary nor desirable for ossicular implants, because (1) they may need to be removed or replaced in the future and (2) their solid fixation to an ossicle is not necessary for the vibratory function of hearing amplification.

Long-term results for the Xomed Audiant Bone Conductor.

The Audiant Bone Conductor is now used worldwide. Results consistently demonstrate that when used on patients within the recommended criteria, hearing thresholds are improved to within 10 dB of the preoperative bone conduction threshold. In this article, comparisons are made with the reported results of the Audiant versus other comparable bone conduction devices, or with surgical procedures for conditions such as congenital aural atresia.

The Audiant Bone Conductor: update of patient results in North America.

The Xomed Audiant Bone Conductor is an implantable hearing device for conductive hearing impairments not adequately relieved by surgical methods or hearing aid amplification. It has now been used long enough for analysis of its present position in our management armamentarium. Data obtained from respondents from the United States and Canada are presented and indicate that this device, properly prescribed and used, almost eliminates the conductive elements of the hearing impairment. During the early years of its use, the device was frequently implanted in patients outside the manufacturer's guidelines for use. Some of the reasons for this discrepancy, as well as evidence that this misapplication is lessening, are presented. When proper guidelines were used, however, the results presented here indicate that socially adequate hearing can be restored to patients with conductive loss by the Audiant. Complications have been few and appear to be diminishing. The results indicate that this device has, in its present state of development, a narrow and restrictive application, but a well-defined and efficient role to play in the management of conductive hearing impairment.

Stapedectomy. Causes of failure and revision surgery in otosclerosis.

The greatest chance of success in stapedectomy is at the time of the initial procedure. Complications are compounded and successes markedly decreased when revision surgery is attempted. The most common pitfalls encountered in stapedectomy are reviewed in this article. Principles of surgery that have minimized complications and decreased the need for revision procedures in the authors' practices are outlined. Guidelines helpful when considering revision surgery also are presented and specific indications are addressed.

Kabuki make-up syndrome and hearing impairment.

In 1981, Niikawa et al. and Kuroki et al. independently described patients with a new syndrome consisting of mental retardation, postnatal growth deficiency and unusual facial features such as long palpebral fissures with eversion of the lateral one-third of the lower eyelids, arched and laterally sparse eyebrows and large prominent ears among other malformations. The condition has been called Kabuki make-up syndrome because the facial features in affected individuals resemble the make-up of the actors in a Japanese play: Kabuki. After the initial reports on Japanese individuals, the condition has been observed in several other patients of different ethnic origins including a few patients from this country (Kaiser-Kupfer et al., 1986; Pagon et al., 1986). We describe an additional 13-year-old male patient with Kabuki make-up syndrome with possible implication of autosomal dominant inheritance from his mother. Interestingly, our patient also displayed hitherto unreported severe ossicular malformations resulting in significant hearing impairment.

The safety and effectiveness of an implanted electromagnetic hearing device.

The records of 184 patients implanted with the XOMED Audiant Bone Conductor (XOMED Inc, Jacksonville, Fla) prior to March 1988 were reviewed retrospectively to determine the safety of this device. Complications were few and minor in nature. Effectiveness was judged from the audiometric data obtained from the 96 patients in the hearing part of this study, all of whom had improved hearing with the device. The mean preoperative pure-tone air-conduction three-frequency average threshold +/- SD in the implanted ear was 55.8 +/- 10.7-dB hearing level; postoperative average aided warble-tone threshold was 19.9 +/- 8.5-dB hearing level. The average improvement in threshold was 36.0 +/- 13.3 dB. Ninety-three percent of patients achieved socially adequate hearing, ie, mean aided sound-field thresholds of at least 30-dB hearing level, and 81% had thresholds of at least 25-dB hearing level. We conclude that the XOMED Audiant Bone Conductor is a safe and effective device for the surgical correction of conductive hearing loss.

Experiences with the Nucleus multichannel cochlear implant in three young children.

Clinical trials for the Nucleus multichannel cochlear implant in children 2 through 9 years of age have been ongoing for approximately 1 year. We describe three children who have used the device for at least 8 months. Based on these three cases, we discuss some factors that might affect the outcome of the Nucleus implant in young children: age at implantation, age at onset of deafness, and duration of profound deafness before implantation. Surgical and rehabilitation issues, including educational settings, are reviewed.

Histologic findings in two very small intracanalicular solitary schwannomas of the eighth nerve: II. "Onion bulbs".

An "onion bulb" is a descriptive histologic term referring to concentric layers of Schwann cell processes about a myelinated nerve fiber. Between the layers of Schwann cells are increased amounts of longitudinally oriented collagen fibers. It is thought that onion bulbs form as a result of sequential segmental demyelination and remyelination attempts. This process can become so severe that the myelinated fiber loses its myelin and ultimately degenerates; however, many fibers remain viable and thinly myelinated. The physiologic effect of "onion bulbs" is to markedly decrease conduction velocity in the fiber affected. In the auditory system, incompletely myelinated cochlear nerve fibers in the infant and in patients with multiple sclerosis show delays of the auditory evoked potential latencies and psychoacoustic retrocochlear patterns. No anatomic substrate has been identified for these auditory tests patterns in the acoustic tumor (solitary schwannoma of the eighth nerve). Two very small intracanalicular acoustic tumors were resected en bloc with the nerve of origin, serially sectioned, stained for neural tissue, and studied by light microscopy. In both tumors, histologic findings consistent with onion bulb formation were discovered about some of the myelinated nerve fibers found deeply incorporated in the tumor mass. These findings suggest that demyelination, perhaps with the formation of onion bulbs, may be a histopathologic correlate for retrocochlear dysfunction seen in acoustic tumors.

An implantable hearing device: osseointegration of a titanium-magnet temporal bone stimulator.

The use of bone conduction hearing devices has recently entered the realm of implantable prostheses and solid-state electronics, resulting in improved fidelity and applicability for a wider range of patients. One particular device, a temporal bone stimulator (TBS), consists of an external sound processor and implanted portion to cause vibration under the skin. An implantable temporal bone stimulator screw constructed of titanium alloy with a permanent magnet can be vibrated by inductive transcutaneous coupling. The safety and osseointegration of the TBS bone screw were tested in adult goats that were free-field stimulated at 75 dB with the TBS processor for 4 to 21 weeks. Histologic comparisons of the soft tissue and bone adjacent to active and passive screws revealed no remarkable differences between them with bone growing in the interstices of the threaded portion. Evidence for mild reorganization of bone was shown with Goldner's stain, which differentiated bone that was young and unmineralized from bone that was older and mineralized. Reorganization was evident in both the active and passive sites and there was no remarkable difference between the two in a blind study. Additional evidence for the integrity of the implant was obtained by subjecting a calvarium containing both screws to a 5000 gauss magnetic field for 10 minutes of a nuclear magnetic resonance head scan. The calvarium was first dissected free from overlying skin and connective tissue. The magnet-containing screws were not loosened. We conclude that the implanted screw portion of the TBS implantable hearing device is well-integrated into the temporal bone. Mild stimulation of new bone growth indicates a healthy long-term viable implant for bone conduction amplification of sound.