Long-Term Follow-Up in Active Transcutaneous Bone Conduction Implants

OBJECTIVE

To evaluate long-term outcomes of active transcutaneous bone conduction implants (atBCIs) regarding safety, hearing, and quality of life.

STUDY DESIGN

A clinical study with retrospective medical record analysis combined with prospective audiometry and quality of life questionnaires.

SETTING

Three secondary to tertiary care hospitals.

PATIENTS

All subjects operated with an atBCI in three regions in Sweden were asked for informed consent. Indications for atBCI were single-sided deafness (SSD) and conductive or mixed hearing loss (CMHL).

INTERVENTION

Evaluation of atBCI.

MAIN OUTCOME MEASURES

Pure tone and speech audiometry and Glasgow Benefit Inventory (GBI).

RESULT

Thirty-three subjects were included and 29 completed all parts. The total follow-up time was 124.1 subject-years. Nineteen subjects had CMHL and in this group, pure tone averages (PTA4) were 56.6 dB HL unaided and 29.6 dB HL aided, comparable with a functional gain of 26.0 dB. Effective gain (EG) was -12.7 dB. With bilateral hearing, Word Recognition Scores (WRS) in noise were 36.5% unaided and 59.1% aided. Fourteen subjects had SSD or asymmetric hearing loss (AHL) and in this group, PTA4 were >100 dB HL unaided and 32.1 dB HL aided with the contralateral ear blocked. EG was -9.1 dB. With bilateral hearing, WRSs were 53.2% unaided and 67.9% aided. The means of the total GBI scores were 31.7 for CMHL and 23.6 for SSD/AHL.

CONCLUSION

Few complications occurred during the study. The atBCI is concluded to provide a safe and effective long-term hearing rehabilitation.

Outcomes after Application of Active Bone Conducting Implants

BACKGROUND

A bone conducting implant is a treatment option for individuals with conductive or mixed hearing loss (CHL, MHL) who do not tolerate regular hearing aids, and for individuals with single-sided deafness (SSD). An active bone conducting implant (ABCI) was introduced in 2012 with indication in CHL, MHL, and SSD, and it is still the only ABCI available. With complete implantation of the active transducer and consequent intact skin, a decrease in infections, skin overgrowth, and implant losses, all common disadvantages with earlier passive bone conducting implants, could be expected. Our Ear, Nose and Throat Department, a secondary care center for otosurgery that covers a population of approximately 365,000 inhabitants, was approved to implant ABCIs in 2012.

OBJECTIVES

Our aim was to conduct an evaluation of audiological and subjective outcomes after ABCIs.

METHOD

A cohort study with retrospective and prospective data collection was performed.The first 20 consecutive patients operated with an ABCI were asked for informed consent. The main outcome measures werepure tone and speech audiometry and the Glasgow Benefit Inventory (GBI).

RESULTS

Seventeen patients accepted to participate and 15 were able to complete all parts. Six patients had CHL or MHL. In this group the pure tone audiometry tests are comparable with an average functional hearing gain of 29.8 dB HL. With bilateral hearing, the mean Word Recognition Score (WRS) in noise was 35.7% unaided and 62.7% aided. Ten patients had the indication SSD. With the hearing ear blocked, the pure tone average was >101 dB HL, compared to 29.3 dB HL in sound field aided. With bilateral hearing, the mean WRS in noise was 59.7% unaided and 72.8% aided. The mean of the total GBI score was 42.1 in the group with CHL or MHL and 20.6 in the group with SSD.

CONCLUSIONS

The patients benefit from their implants in terms of quality of life, and there is a substantial hearing gain from the implant for patients with conductive or MHL. Patients with SSD benefit less from the implant than other diagnoses but the positive outcomes are comparable to other options for this group.