Baha System Research Articles

The Bone-Anchored Hearing Aid for children: Recent developments

In 1984 the Bone-Anchored Hearing Aid, or BAHA, system was introduced. Its transducer is coupled directly to the skull percutaneously to form a highly effective bone-conduction hearing device. Clinical studies on adults with conductive hearing loss have shown that the BAHA system outperforms conventional bone-conduction hearing aids. Therefore, the next step was to apply the BAHA system in children with congenital or acquired conductive hearing loss. Reviewed data showed that, on average, such children benefited significantly more from the BAHA than from reconstructive surgery. Thus, BAHA application appears to be the best option to achieve normal communication and speech and language development in children with bilateral conductive hearing loss. However, in children under the age of three to four years, a conventional solution must be applied, e.g. a bone conductor with a transcutaneous coupling, because they are too young to undergo BAHA implant surgery. In the case of unilateral congenital conductive hearing loss, there is no convincing evidence in the clinical literature for early intervention.In summary, the BAHA system can be considered a new, indispensable tool for children with bilateral conductive hearing loss.

Wertigkeit der BAHA-Testung für das postoperative Hörergebnis

Bone-anchored hearing aids provide a therapy option for patients with conductive and mixed hearing loss, with the possibility of audiological rehabilitation. Test rod and tension headband offer the patient a preoperative impression of their postoperative hearing. The aim of this study was to evaluate the tools available for preoperative assessment of candidates for bone-anchored hearing aids and to ascertain predictive audiometric values. Following implantation of a BAHA Compact system, sound and speech audiograms were performed in each of 16 patients with the bone-anchored BAHA device and with test rod and tension headband. Both with the BAHA and with the test devices, closure of the air-bone gap occurred and resulted in a clear improvement in hearing threshold and speech perception. The threshold increase with the BAHA was 9 dB greater on average (mean) than that measured with the test rod and the tension headband. Examinaation of speech perception indicated a mean advantage of 14-20% for the anchored BAHA system over the tension headband in monosyllabic testing. Preoperative testing before providing a BAHA system is a good way of predicting what level of hearing and speech perception can be expected after implantation.

Osseointegration Timing for Baha System Loading

The process of osseointegration for creating a biological bond between titanium oxide and bone is time dependent. However, different surgeons have used very varied time frames before loading the implant. The waiting time in dental implant loading ranged from immediate to 6 months. The Baha system (Cochlear Limited, Englewood, CO) traditional waiting period consisted of 3 months for adults and 4 to 6 months for children. The purpose of the study was to evaluate the safety of reducing the waiting time to 6 weeks in adults. Retrospective study of patients who underwent Baha implantation and exteriorization between March, 2004 and July 2005. Twenty-six adult patients underwent Baha titanium implantation and exteriorization in a single stage. They were loaded with the external processor after an average of 6.5 weeks. The etiology of their hearing loss (HL) included conductive HL, mixed HL, and unilateral sensorineural HL. Follow-up period ranged between 6 and 20 months. All patients were successfully implanted with the titanium implants, loaded at the 6 week interval, and have safely retained their prosthesis. The only reported complication was dermatitis, which occurred in three patients. Patients were pleased to receive the external processor earlier. The reduction of the waiting period from 3 months to 6 weeks did not result in any failure of osseointegration of the titanium implants. The earlier activation resulted in enhanced patient satisfaction. A larger series would be needed to definitively recommend shortening of the interval between Baha implantation and device loading.

Consensus Statement on the BAHA System: Where Do We Stand at Present?

Consensus Statement on the BAHA System: Where Do We Stand at Present?

Canal atresia: “Surgery or implantable hearing devices? The expert's question is revisited”

(1) Evaluate hearing results in patients managed with external auditory canal reconstruction; (2) compare results to the expectations from treatment with surgical; placement of an osteo-integrated bone-conduction device (BAHA system); (3) assess complications of both interventions; (4) evaluate the medical cost-effectiveness of each avenue of management at 2005 rates for billings based upon relative value units (RVUs). (1) Retrospective chart review for 36 ears in 29 pediatric patients who underwent surgical canal reconstruction at a tertiary-care pediatric hospital in a major urban center with assessment of management techniques and surgical and audiologic outcomes. (2) Retrospective chart review of six pediatric patients who underwent BAHA placement in a major urban center with assessment of management techniques and surgical and audiologic outcomes. (3) Cost reassessment at 2005 billings rates based upon RVUs for canal reconstruction versus BAHA system and comparative analysis. (1) The average post-operative hearing loss in the right ear was 34.3 dB left ear was 31.6 dB. The average gain per ear was 17.3 dB. (2) Twenty-seven (93%) of EAC reconstruction patients required some form of amplification post-operatively. (3) Data available for three of the BAHA patients reflected the predicted average gain in dB (predicted 34.3 dB, observed 31.8 dB). (4) Early complications of canal reconstruction included removal of the packing by the patient, post-operative bleeding and post-operative hematoma. (5) Late complications included recurrent canal stenosis, recurrent otitis externa, canal prolapse and canal cholesteatoma. (6) Uncomplicated external auditory canal reconstruction cost $51,505.98 or $2909.94/dB of hearing gain based upon billings fro RVUs. (7) Uncomplicated two-staged BAHA system placement cost $42,448.85 or $1237.57/dB of hearing gain based upon billings for RVUs. (8) Uncomplicated single-staged BAHA system placement cost $28,341.00 or $826.27/dB of hearing gain based upon billings for RVUs. Study results indicate that even with significant investments in EAC reconstruction, most patients still required some form of amplification. There are also significant risks of early and late complications from the reconstructive procedure. Studies indicate and our results support that the osteo-integrated bone-conduction device (BAHA system) can achieve truly acceptable hearing (<or=15 dB) in school-aged children with normal bone curves, and it can match the bone-curves for children with sensorineural hearing loss. The two-staged BAHA system placement may be provided at almost one-third the cost to the medical system, on a decibel-for-decibel basis. The single-stage BAHA system placement yields even greater cost savings at just over one-quarter of the cost of surgical EAC reconstruction on a decibel-for-decibel basis. Additionally, there are fewer complications and fewer follow-up visits for the care of the implant system. This is an added value to the parents and patient for the savings in opportunity costs related to the lost time at work and school for office visits and peri-operative care. Overall, it appears that osteo-integrated bone-conduction devices may provide a higher quality of outcome for patients while resulting in significant economic savings.

The bone-anchored hearing device (BAHA)

The bone-anchoring hearing device (BAHA) is an osseointegrated system that is used for hearing rehabilitation through direct bone conduction. The indications for the BAHA include unilateral and/or bilateral conductive or mixed hearing loss, and unilateral profound sensorineural hearing loss. When used for unilateral profound sensorineural hearing loss, the BAHA acts as a bone conduction CROS (contralateral routing of off-side signal) device transmitting the signal from the deaf side through the skull to the contralateral cochlea. The surgical procedure to place the abutment and titanium screw is straightforward. In general, the satisfaction rate is very high for patients using the BAHA system.

BAHA®: The Direct Bone Conductor.

The BAHA® device uses the principle of direct bone conduction (DBC) to overcome several of the drawbacks of conventional air-conduction (AC) and bone-conduction (BC) hearing aids for patients with conductive or mixed hearing loss. Recent developments of the BAHA system have made it more user friendly and the device has been further miniaturized. The FDA has cleared the device for both adults and pediatrics (from age 5 and up) and also for bilateral fitting. With the BAHA system, a vibrating transducer is directly connected to the skull bone, of which the cochlea is an integrated part. This principle of DBC provides a more or less direct and clear transmission pathway to the cochlea. The BAHA surgery is, however, a minor surgical procedure and does not in any way interfere with the hearing organ so there are no risks of damaging the ear or the residual hearing. Scientific papers about BAHA from around the world report high performance, safety, and patient satisfaction. (Tjellstrom and Granstrom, 1995; Powell et al., 1996; Hartland et al., 1996; Papsin et al., 1997; Tietze et al., 2001; Tjellstrom and Hakansson, 2001; Snik et al., 2001; Lustig et al., 2001). Today, more than 9000 patients around the world have been treated with BAHA.

Rehabilitation in Franceschetti Syndrome: An Interdisciplinary Approach Using Bone-Anchored Hearing Aids

The purpose of the study was to determine the effectiveness of a concept of combined interdisciplinary rehabilitation for children with mandibulofacial dysostosis, developed at the Center for Facial Malformations. It consists of binaural implantation of bone-anchored hearing aids and gradual distraction of the mandible. After audiological testing and mandibular distraction on a phantom head designed with data from a spiral CT, the surgery was done in three steps: implanting the fixtures for BAHA and the bone-lengthening device, removing the device after six weeks and completing the BAHA implantation two months later. The distraction procedure and orthodontic treatment were performed on an outpatient basis. The results (six patients, ages 6-19 years) were excellent: after implantation of the BAHA system speech perception increased from approximately 85% with the conventional BCHA to 95-100% with the BAHA. Quality of life was reported to be much better because of the general cosmetic improvement as well as the good acoustic orientation and sound quality with the new hearing devices. We conclude that the interdisciplinary approach provides favorable conditions for rehabilitation in cases of complex malformations of the head and neck.