The Need for Vestibular Implants in a Tertiary Referral Ear, Nose, and Throat Center and Its Relation to Hearing Status.

BACKGROUND: Patients with bilateral vestibulopathy (BVP) are at increased risk of falling and have poor quality of life. Several research groups are currently developing and investigating vestibular implants to treat BVP. The goal was to identify how many patients can be considered eligible for vestibular implantation. METHODS: The objective vestibular implantation criteria for research were applied to the results of the caloric irrigation test, the sinusoidal harmonic acceleration test, the video head impulse test, and the cervical and ocular vestibular evoked myogenic potential tests. RESULTS: Vestibular implant eligibility was situated between 3.6% and 15.7% (semicircular canal implant: 3.6%; otolith implant: 15.7%; combined implant: 4.8%). Only 16 out of the 29 patients (55%) eligible for a vestibular implant had bilateral severe-to-profound hearing loss. The remaining 45% (13/29) thus have better hearing in at least 1 ear. CONCLUSION: Vestibular implant eligibility in an ear, nose, and throat department was situated between 3.6% and 15.7%, depending on the type of implant that was considered. In addition, the data showed that 45% of the eligible patients had normal-to-moderate hearing in at least 1 ear. In other words, only recruiting patients with (bilateral) severe-to-profound hearing loss for vestibular implantation leads to the systematic exclusion of about half of the candidates. Structure-preserving surgical techniques are thus a major future challenge in the field of vestibular implantation.

Headbands, testbands and softbands in preoperative testing and application of bone-anchored devices in adults and children.

The headbands, the testbands and the softbands are applied for coupling of the sound processors of the bone-anchored devices to the patient's head before the titanium fixture/abutment can be implanted. The bands are used for acute and/or prolonged testing of the bone-anchored devices, and are able to approximate the results of postoperative amplification. Yet, whatever the type of the band coupling, the transducers interface with the bone through a layer of skin and subcutaneous tissue that damp the transmission and decrease effective amplification. Therefore, the final hearing result with the bone-anchored device after implantation is usually better than with the sound processor attached to the headband, testband or softband, especially in the high-frequency zone. The results of our studies performed in experienced Baha Compact users quantified the magnitude of the skin damping and showed significant threshold differences for frequencies 1-4 kHz (in the range of 5-20 dB) when the Baha was coupled to the implanted fixture/abutment, as compared to the headband or the testband. These differences were also reflected in speech audiometry with the speech reception threshold improvement of approximately 4-7 dB. Suboptimal character of audiometric thresholds and speech understanding scores found during the preoperative testing period must be carefully considered in patient counseling, because such suboptimal results obtained preoperatively could demotivate the patients from using the Baha. Audiometrical results obtained with the headband and the testband are comparable; therefore, the more comfortable headband is also suitable for the preoperative audiological evaluation, especially in children.

Skin reactions following BAHA surgery using the skin flap dermatome technique.

The objectives of the study were to determine the incidence of skin reactions and complications associated with bone-anchored hearing aid (BAHA) implantation. The study is a retrospective case review done in a tertiary referral center. One hundred thirty-eight consecutive patients between 1998 and 2008 underwent implantation of a BAHA and were regularly seen for follow-up. Indications included conductive or mixed hearing loss where a hearing aid cannot be used and since 2000 also had contralateral single-sided perceptive hearing loss. BAHA implantation was done by creating a pedicled flap using the skin flap dermatome technique. Postoperative incidence of skin reactions and complications were measured. Significant postoperative complications requiring revision surgery occurred 37 times in 30 patients. Normal skin healing was seen in 52 patients (63.4%), while abnormal skin healing occurred in 30 patients (36.6%). This study showed that skin problems occur more often than expected. Because of the skin problems with the skin flap technique, the authors have switched to the linear incision technique, hoping to decrease the incidence of skin problems.

Comparison of the audiologic results obtained with the bone-anchored hearing aid attached to the headband, the testband, and to the "snap" abutment.

OBJECTIVES: 1) To quantify the audiometric differences between the preoperative tests with the Bone-Anchored Hearing Aid (BAHA) attached to the headband or the testband and the final postoperative result with the BAHA positioned at the implanted abutment. 2) To compare the results obtained with the headband and the testband. 3) To quantify the magnitude of the damping through the skin for the BAHA placed at the testband (important for comparison with the implantable hearing aids). STUDY DESIGN: Prospective. SETTING: Tertiary otological referral centre. PATIENTS: Ten adult (> or = 14 yr old) BAHA patients (6 male and 4 female subjects) with bilateral air-bone gaps of minimum 40-dB hearing loss and with more than 6 months of BAHA experience with the BAHA "Compact." METHODS: Audiometric free-field thresholds and speech audiometry scores (Consonant-Vowel-Consonant lists, phonemic score) have been evaluated for 3 conditions: BAHA attached to the implanted "Snap" abutment, to the headband, or to the testband. RESULTS: For frequencies 1 to 4 kHz, significant differences in the range of 5 to 20 dB were found between the BAHA coupled with the Snap abutment and the preoperative testing conditions with the BAHA positioned at the headband or the testband. These differences were also reflected in the speech audiometry with a difference in speech reception threshold of approximately 4 to 7 dB. CONCLUSION: 1) Significant differences in the audiometric thresholds and the speech understanding scores were found between the preoperative test conditions and the final postoperative result. 2) Audiometric results obtained with the headband and the testband are comparable; therefore, the more comfortable headband is also suitable for the preoperative audiologic evaluation. 3) The magnitude of the skin damping must be accounted for when referring to the audiometric results obtained with the BAHA attached to the testband or headband.