The Carina© middle ear implant: surgical and functional outcomes

Abstract

The Carina© system (Cochlear Ltd, Sydney, Australia) is a totally implantable prosthesis designed to meet the needs of acoustic amplification in adults with moderate-to-severe sensorineural or mixed hearing loss. It mechanically stimulates the ossicles or labyrinthine windows. The object of this study was to update surgical and functional results obtained in a consistent sample of Carina© recipients. The data sheets of 26 patients who underwent Carina© surgery at two ENT units [i.e., ENT Audiology and Phoniatrics Unit of the University Hospital of Pisa (Pisa, Italy) and ENT Unit of "Guglielmo da Saliceto" Hospital of Piacenza (Piacenza, Italy)] were evaluated for the surgical and audiological outcomes. Twenty patients received a unilateral device, whereas six patients were bilaterally implanted (simultaneously in one patient and sequentially in the remaining five patients). The total number of ears implanted in this study was 32. Most implanted patients expressed a high degree of satisfaction with the prosthesis, which highlights the improvement in hearing in different environmental conditions, the cosmetic advantages, and greater freedom in performing common activities in daily living. Audiological examination demonstrated valid functional gain and significant improvement in speech perception in quiet. Based on this experience, the Carina© is a valid alternative to hearing aids. Moreover, a bilateral implantation, even a simultaneous implantation, is a viable option for selected motivated patients because the intervention is generally well tolerated and the surgery time is relatively fast.

A Retrospective Multicentre Cohort Review of Patient Characteristics and Surgical Aspects versus the Long-Term Outcomes for Recipients of a Fully Implantable Active Middle Ear Implant

“…Although it is difficult to compare definitively, it is likely that the most frequent microphone location used in our study, the posterior inferior mastoid line (position B), is consistent with that most used and described as "close to the mastoid tip" by Bruschini et al [2016]. As mentioned above, their earlier work confirmed the need to consider microphone location and its impact on the feedback loop with possible repositioning when not optimal for the individual [Bruschini et al, 2010].…”

“…To date, published guidelines on the identification of the optimal site for microphone placement, the surgical procedure and the impact upon outcomes have not been reported in detail, referring to "recommendations by the manufacturer" Martin et al, 2009;Bruschini et al, 2016]. Description of the microphone placement has been explored in a cohort of 32 ears as in the mastoid area with variations in the method used to place the microphone as either in "a subcutaneous pocket formed between the skin and the sternocleidomastoid muscle near the mastoid tip" for the majority of cases or as "fixed over the mastoid surface close to the mastoid tip" [Bruschini et al, 2016].…”

“…Description of the microphone placement has been explored in a cohort of 32 ears as in the mastoid area with variations in the method used to place the microphone as either in "a subcutaneous pocket formed between the skin and the sternocleidomastoid muscle near the mastoid tip" for the majority of cases or as "fixed over the mastoid surface close to the mastoid tip" [Bruschini et al, 2016]. Clinically, they observed no influence of the microphone location upon system performance with particular mention of no impact upon the incidence of feedback which occurred rarely.…”

“…The use of an internally implantable microphone of a fully implantable active middle ear implant (AMEI) will influence the acoustic performance of the system, the daily users' physical comfort and the perception of sound quality and reception of desired external sound sources and undesired internal noises [Bruschini et al, 2010;Kam et al, 2013;Zwartenkot et al, 2013;Bittencourt et al, 2014;Pulcherio et al, 2014;Savas et al, 2016;Bruschini et al, 2016]. While the surgical considerations for placement of semi-implantable and fully implantable AMEIs remain largely the same, special attention is needed for the implantable microphone component.…”

Stability of the standard incus coupling of the Carina middle ear actuator after 1.5T MRI

“…Over the last decades, a number of different active middle ear implants (AMEI) have shown a succesful outcome in patients with different types of pathologies and hearing losses. The Carina 1 implant (Cochlear Ltd., Sydney, Australia) is the only fully-implantable AMEI for patients with moderate to severe sensorineural, conductive or mixed hearing loss currently on the market [1]. The Carina AMEI features a sensitive implantable subcutaneous microphone to pick up sound which is amplified in the implant body and converted into mechanical vibrations by the implantable actuator to stimulate a patient.…”