Planned simultaneous bilateral cochlear implant operations: How often do children receive only one implant?
Introduction
Pediatric bilateral cochlear implantation has become increasingly common in the past decade, with demonstrated benefits including improved spatial hearing and listening in noise [1], [2], [3], [4]. Bilateral cochlear implantation can be performed as sequential or simultaneous procedures. In a sequential procedure, the contralateral ear is implanted months or years after the first implant operation. In a simultaneous procedure, two cochlear implants are inserted in a single operation. A multi-country survey of implant procedures conducted in 2007 showed that 65.6% (378 out of 576) of all pediatric bilateral cochlear operations were sequential procedures and 34.4% were simultaneous procedures [5]. For children under the age of 3 years, 58% of bilateral operations were simultaneous procedures. The lower proportion of simultaneous procedures in older children is a reflection of the fact that the majority of bilateral implant candidates in this age range will already have received a first implant.
There are some advantages to receiving bilateral implants simultaneously rather than sequentially. Firstly, both implants will be received when the child is as young as possible, thus minimizing the duration of deafness in both ears. Secondly, there will be no period of unilateral implant use, thus avoiding potential dominance within the auditory system of input via one ear. Electrophysiological studies suggest these advantages may promote the development of binaural processing [6]. There are also practical advantages for simultaneous implants as only one operation is required. The implant operation is emotional and stressful for the family and the child and it is preferable to only undertake this once. A single operation will also result in time and cost savings. Post-operatively, establishing full-time bilateral implant use has been shown to be easier and faster for simultaneously implanted children, and they are less likely to develop a preference for one implant over the other [7]. Given that age at implant and amount of listening experience are important factors in the outcomes achieved with a cochlear implant, early implantation of each ear at the same age and full-time use of both implants is likely to promote the development of equivalent listening skills with each implant alone.
To make an informed choice about proceeding with any cochlear implant procedure, families should be provided with as much information as possible [8]. Now that the multiple options of a unilateral cochlear implant, sequential bilateral cochlear implants, and simultaneous bilateral cochlear implants are available at many clinics, the level of complexity in parental decision making has increased. The increased number of options adds to the amount of information clinicians need to provide during pre-operative counseling. A specific issue to discuss when families are considering simultaneous implantation is the possibility that both ears may not be implanted in a planned simultaneous procedure. There is limited information in the literature on which to base such a discussion. Ramsden et al. [9] examined 50 consecutive pediatric simultaneous procedures and reported that no operation resulted in a first-side cochlear implant only, however the author did emphasize that parents must understand this outcome is a possibility. There are no other reports in the literature which indicate the frequency with which a planned simultaneous procedure results in a first-side implant only, however, it is the clinical experience of the present authors that at least some planned simultaneous operations result in a first-side implant only. In order for evidence-based discussions to be conducted with parents pre-operatively, it is necessary for clinics to document the outcomes of planned simultaneous operations.
The aim of this study was to examine planned pediatric simultaneous cochlear implant operations at the Cochlear Implant Clinic in Melbourne to determine the number of operations which proceeded as planned versus those which resulted in the implantation of a first-side cochlear implant only.
Section snippets
Method
A retrospective survey was conducted of cochlear implant operations on pediatric patients (less than 18 years of age at the time of surgery) at The Royal Victorian Eye and Ear Hospital/The University of Melbourne Cochlear Implant Clinic (the Melbourne Cochlear Implant Clinic). The Melbourne Cochlear Implant Clinic has been conducting pediatric bilateral cochlear implant operations since September 2003. Simultaneous cochlear implants have been an option for children meeting the audiological and
Results
As shown in Fig. 1, a total of 221 operations, involving 197 pediatric patients, were conducted from January 2007 to the end of July 2010. Eighty-seven (44.2%) patients received only a first-side cochlear implant. Although a proportion of these patients are likely go on to have a second-side cochlear implant in the future, the present report deals only with operations conducted up to the end of July 2010. As indicated by the shaded area of the figure, 110 (55.8%) of the patients received
Discussion
There has been a trend at the Melbourne Cochlear Implant Clinic for an increasing proportion of pediatric implant procedures to be bilateral operations. In the year 2006, bilateral implant operations made up only 17% (8 out of 47) of pediatric operations. From January 2007 to July 2010 (the time period examined in the present study) bilateral implant operations made up 49.8% (110 out of 221) of pediatric operations. Looking more specifically at the rates of simultaneous versus sequential
Acknowledgments
The authors are grateful to the staff of the Royal Victorian Eye and Ear Hospital Cochlear Implant Clinic for their support of this work. Ethical approval for this work was given by the Human Research Ethics Committee of the Royal Victorian Eye and Ear Hospital, Melbourne (Project No. 04/564H/09). Financial support for this work was provided by the National Health and Medical Research Council (Project Grant No. 454318) and the Department of Otolaryngology at The University of Melbourne. Nobody
References (15)
- et al.
Auditory brainstem activity in children with 9–30 months of bilateral cochlear implant use
Hear. Res.
(2007) - et al.
Hearing benefits of second-side cochlear implantation in two groups of children
Int. J. Pediatr. Otorhinolaryngol.
(2007) - et al.
Sound localization ability of young children with bilateral cochlear implants
Otol. Neurotol.
(2007) - et al.
Sound localization skills in children who use bilateral cochlear implants and in children with normal acoustic hearing
Ear Hear.
(2010) - et al.
Bilateral or unilateral cochlear implantation for deaf children: an observational study
Arch. Dis. Child.
(2010) - et al.
Earlier intervention leads to better sound localization in children with bilateral cochlear implants
Audiol. Neurootol.
(2010) - et al.
Worldwide trends in bilateral cochlear implantation
Laryngoscope
(2010)