Cytokine expression profile in the bone‐anchored hearing system: 12‐week results from a prospective randomized,controlled study

Objective

To study the effect of implanting the percutaneous bone‐anchored hearing system (BAHS) itself and inflammation of the peri‐abutment skin warrant clarification. In this study, we aimed to acquire further insight into the immune responses related to BAHS surgery and peri‐implant skin inflammation.

Materials and Methods

During surgery and 12 weeks post‐implantation, skin biopsies were obtained. If applicable, additional biopsies were taken during cases of inflammation. The mRNA expression of IL‐1β, IL‐6, IL‐8, TNFα, IL‐17, IL‐10, TGF‐ß, MIP‐1α, MMP‐9, TIMP‐1, COL1α1, VEGF‐A, FGF‐2 TLR‐2, and TLR‐4 was quantified using qRT‐PCR.

Results

Thirty‐five patients agreed to the surgery and 12‐week biopsy. Twenty‐two patients had mRNA of sufficient quality for analysis. Ten were fitted with a BAHS using the minimally invasive Ponto surgery technique. Twelve were fitted with a BAHS using the linear incision technique with soft‐tissue preservation. Five biopsies were obtained during episodes of inflammation. The post‐implantation mRNA expression of IL‐1β (P = .002), IL‐8 (P = .003), MMP9 (P = .005), TIMP‐1 (P = .002), and COL1α1 (P < .001) was significantly up‐regulated. IL‐6 (P = .009) and FGF‐2 (P = .004) mRNA expression was significantly down‐regulated after implantation. Within patients, no difference between post‐implantation mRNA expression (at 12 weeks) and when inflammation was observed. Between patients, the expression of IL‐1β (P = .015) and IL‐17 (P = .02) was higher during cases of inflammation compared with patients who had no inflammation at 12‐week follow‐up.

Conclusions

As part of a randomized, prospective, clinical trial, the present study reports the molecular profile of selected cytokines in the soft tissue around BAHS. Within the limit of this study, the results showed that 12 weeks after BAHS implantation the gene expression of some inflammatory cytokines (IL‐8 and IL‐1β) is still relatively high compared with the baseline, steady‐state, expression. The up‐regulation of anabolic (COL1α1) and tissue‐remodeling (MMP‐9 and TIMP1) genes indicates an ongoing remodeling process after 12 weeks of implantation. The results suggest that IL‐1β, IL‐17, and TNF‐α may be interesting markers associated with inflammation.     

骨锚式助听器（BAHA）的临床应用（附2例报告）

目的探讨骨锚式助听器（BAHA）的临床应用价值。方法对2例先天性双外耳道闭锁的传导性聋患者行骨锚式助听器治疗,对其术后听力效果,言语发育,植入体的稳定性和有无并发症进行分析。结果①固定助听器的钛螺钉植入牢固,随访8年无一例松动脱出;②配戴BAHA后在500Hz,1KHz,2KHz,3KHz,4KHz（声场测试）,气导平均提高了33dB,获得良好的听力效果,儿童患者言语发育在使用该助听器后达到了正常同龄儿童的水平．两患者使用助听器时间每天均超过8小时;③钛螺钉植入周围皮肤虽易出现感染．但易控制,未引起不良反应和严重并发症。结论在严格掌握适应症情况下,使用BAHA对先天性双外耳道闭锁的传导性聋患者有好的临床价值。     

骨锚式助听器(BAHA)的临床应用(附2例报告)

目的探讨骨锚式助听器(BAHA)的临床应用价值。方法对2例先天性双外耳道闭锁的传导性聋患者行骨锚式助听器治疗,对其术后听力效果,言语发育,植入体的稳定性和有无并发症进行分析。结果①固定助听器的钛螺钉植入牢固,随访8年无一例松动脱出;②配戴BAHA后在500Hz,1KHz,2KHz,3KHz,4KHz(声场测试),气导平均提高了33dB,获得良好的听力效果,儿童患者言语发育在使用该助听器后达到了正常同龄儿童的水平.两患者使用助听器时间每天均超过8小时;③钛螺钉植入周围皮肤虽易出现感染,但易控制,未引起不良反应和严重并发症。结论在严格掌握适应症情况下,使用BAHA对先天性双外耳道闭锁的传导性聋患者有好的临床价值。     

Effects of applied contact force and volume control setting on output force levels of the BAHA® Softband

The BAHA® Softband has been developed to provide a transcutaneous anchor for a BAHA® until a child is a surgical candidate for the percutaneous BAHA® implant. We tested the objective output force level of the BAHA® Classic 300 and Compact connected to a Softband on an artificial mastoid to determine: (1) the effects of direct contact force on output force levels (dB); and (2) the required volume control setting to ensure audibility of speech (assuming an average adult reference equivalent threshold force level).

Direct contact force was varied from 2 to 5 N in 1 N steps. Output force level increased with increasing contact force. However, the average increase was 3 dB or lower, suggesting that the contact force is of minor importance. Volume control setting appears to be of much greater importance. It is suggested that the volume setting of either device be set to at least 2.5 to ensure audibility of conversational speech. Data from normal-hearing adults with simulated conductive hearing losses are presented to validate this conclusion.     

Bone anchored hearing aid in single sided deafness: outcome in right-handed patients

Objective

To assess the benefits in terms of sound localization, to evaluate speech discrimination in noise, to appraise the prosthesis benefit and to identify outcome in right and left handed patients when BAHA are implanted on the right or on the left deaf side.

Methods

Two years prospective study in a tertiary referral center. Tests consist on Hearing in Noise Test (HINT) and sound localization after 6 months of BAHA use. Quality of life was assessed by the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire. The paired T-test and the analysis of variance were used for the statistical measures.

Results

Twenty-one subjects participated in this study. HINT: patients score better when speech and noise are spatially separated and noise is not presented to the healthy ear. In the right-handed group (left dominant brain), unaided left-implanted patients performed better than right-implanted patient when speech is in front and noise to the good ear; when speech is presented to the good ear and noise to the front, aided right-implanted patients performed better than aided left-implanted patients. Sound localization: correct answers attain 35% at best. No statistical difference between the frequencies was found, neither between the left and right implanted patients. APHAB: the score improvement is statistically significant for the global score, the background noise subscale at 5 weeks and for the reverberation subscale at 6 months.

Conclusion

It seems that left dominant hemisphere is able to filter crossed noise better than the right hemisphere. Results of uncrossed speech to the dominant left brain are better than the uncrossed speech to the non-dominant right brain.     

Bone-anchored hearing aid: Why do some patients refuse it?

Objective

Bone-anchored hearing aid (BAHA™) is a proven tool to improve hearing. Nevertheless, there are patients who are candidates for BAHA™ implants that end up refusing the surgery. The objective of this study is to review our BAHA™ experience with particular emphasis on reasons behind the refusal of some candidates.

Methods

A prospective cohort of 100 consecutive new candidates referred to The BAHA™ program in a tertiary health care center. Candidates’ demographics, hearing status, Co-morbidities and audiometeric tests were all recorded. Patients’ acceptance or refusal was noted alongside the reasons to refuse BAHA™.

Results

100 new candidates were seen for BAHA™ assessment, 10 patients were excluded due to incomplete data. There were 68 children and 22 adults. Unilateral Conductive Hearing Loss was the most common reason for consultation (40%), followed by unilateral SNHL (23.3%). Aural Atresia was the commonest clinical finding (36.6%). The commonest reason for refusal was social acceptance by the parents due to concern with cosmesis.

Conclusion

The main reason of BAHA™ surgery refusal, in otherwise eligible candidates, is related to cosmesis. Patients with congenital anomalies were the most likely candidates to accept BAHA™ implants.     

BAHA results in children at one year follow-up: A prospective longitudinal study

Objective

To evaluate audiometric and clinical results of children fitted with a bone-anchored hearing aid with specific emphasis on speech discrimination in different sound environments after one year of use.

Methods

We performed a prospective longitudinal study. Seventeen patients between the ages of 5 and 18 years old were included. All patients underwent a complete tonal and vocal evaluation at four pre-determined intervals between the pre-operative period and one-year of bone-anchored hearing aid (BAHA) use. Basic pure-tone average and speech reception threshold were measured in different sound environments. Speech discrimination improvement was tested with the voice originating from the side of the BAHA-fitted ear and with the voice originating from a source directly in front of the patient. These measures were repeated with confounding noise facing the patient then from the side of the affected ear. All tonal and vocal evaluations were performed pre-operatively, the day of processor insertion, 6 months and 12 months after processor insertion.A variance analysis was performed to compare differences in hearing gain with BAHA over time.

Results

Hearing gain with BAHA was clinically and statistically significant at all intervals. Conventional tonal evaluation revealed significantly improved hearing gain after BAHA insertion compared with pre-operative testing with BAHA (26.3 dB vs. 17.3 dB), and this improvement was maintained at one year (27.9 dB). Speech discrimination gain at one year was better than immediately post-insertion (21.9% vs. 11.7%). Maximal gain with BAHA was found with the voice originating from the side of the affected ear and with confounding noise facing the patient (27.1% at one year), whereas the least gain was found in a silent room with the voice coming from straight ahead (11.9% at one year).

Conclusions

Pure-tone average gain at one year post-insertion was similar to immediate post-insertion gain. BAHA aids speech discrimination most when the voice originates from the side of the affected ear with confounding noise facing the patient. Speech discrimination gain improves with time, suggesting an underlying learning process. The best BAHA gain in speech discrimination occurred with background noise.