National study of hearing preservation rates and outcomes after cochlear implantation in Ireland

Abstract

Objective

To study the rate of hearing preservation and outcomes of hearing preservation candidates in a national cochlear implant centre. The HEARRING criteria was used.

Methods

All cochlear implant candidates with preserved low frequency pure tone average (PTA) were included. All patients underwent cochlear implantation using a standard ‘soft-surgery’ technique. PTA was assessed at switch-on, 3, 6, 9 and 12 months postoperatively. The primary outcome was hearing preservation at 12 months.

Results

Sixty six patients were included in the study between 2015 and 2020. Seventy one ears were implanted including 33 adults and 33 children with 5 bilateral implantations. Mean preoperative PTA was 74.8 dB (range 52.3–92 dB), mean postoperative PTA was 95.3 dB corresponding to a mean shift of 20.5 dB. In the adult population, HP rates were as follows: complete HP in 13%, partial HP in 39.1%, minimal HP in 30.4%, loss of hearing in 17.4%. In the paediatric population: complete HP in 20.7%, partial HP in 51.7%, minimal HP in 13.8% and loss of hearing in 13.8%. After the initial postoperative shift, there was no significant worsening of residual hearing during follow-up between 3 and 12 months. There were no significant prognostic factors for hearing preservation.

Conclusion

Hearing preservation rates using the HEARRING criteria are described. This study will help counselling and decision making in patients eligible for cochlear implantation with hearing preservation. Further studies are required to assess the performances and outcomes of electronatural and electroacoustic stimulation.

Keywords:

• Cochlear Implantation
• Cochlear Implants
• Hearing Preservation

Additional information

Notes on contributors

Adrien Gendre

Adrien Gendre graduated in Medicine in the Université François-Rabelais (Tours, France) in 2014. He finished his surgical training scheme in Otolaryngology in Nantes, before completing two fellowships in Dublin, including a 6 months fellowship in the National Hearing Implant and Viani Research Center. He is a fellow of the Royal College of surgeons in Ireland (FRCSI, ORL-HNS) since 2021. He’s currently completing a 1 year fellowship (Chef de Clinique) in Nantes University Hospital. His subspecialty interest is cochlear implantation, neuro-otology and lateral skull base surgery.

Sarah Quinn

Sarah Quinn is currently a medical student at the Royal College of Surgeons Ireland.

Holly Jones

Holly Jones graduated Medicine (MB BCh BAO) in 2016 from University College Dublin. She then began her clinical training in Dublin and is due to start specialty training in Otolaryngology this year.

Originally from Austria, Justin Hintze completed his medical degree and Masters of Bioengineering with Trinity College Dublin. He then went on to pursue a research fellowship with the Mayo Clinic in the USA, where he remains as a research collaborator. Justin is in his 3rd year of the Otolaryngology Higher Surgical training scheme, and is currently also pursuing a PhD in Bioengineering. He is an avid sailor, having recently completed a trans-Atlantic crossing in a Volvo Ocean Racer.

Cristina Simões-Franklin

Cristina Simões-Franklin is a Senior Medical Physicist in the National Hearing Implant and Research Centre, Beaumont Hospital, Dublin.

Peter Walshe

Peter Walshe is a Consultant Otolaryngologist Surgeon in Beaumont Hospital and Temple Street Children's University Hospital, Dublin, Ireland.

Laura Viani

Laura Viani is the Director of the National Cochlear Implant Programme in Ireland and a Consultant Otolaryngologist Surgeon in Beaumont Hospital and Temple Street Children's University Hospital.

Fergal Glynn

Fergal Glynn is a Consultant Otolaryngologist Surgeon in Beaumont Hospital and Temple Street Children's University Hospital, Dublin Ireland.