Since the advent of the cochlear implant more than 20 years ago, the devices have benefited thousands of patients. According to the U.S. Food and Drug Administration, as of April 2009, approximately 188,000 people worldwide have received cochlear implants. In the U.S., about 42,000 adults and 26,000 children have received them. Today, the fantasy of two implanted artificial cochlea is a reality.
At some institutions, it is standard operating procedure to place two implants. In a 2008 article in Current Opinion in Otolaryngology & Head and Neck Surgery, for example, Blake Papsin, MD, and colleagues published an article titled “Bilateral cochlear implants should be the standard for children with bilateral sensorineural deafness.” The authors wrote, “We recommend that simultaneous bilateral implantation be provided when possible and, if not, the inter-stage interval should be limited” (2008;16:69-74). Dr. Papsin is director of the Cochlear Implant Program at The Hospital for Sick Children and professor of otolaryngology at the University of Toronto.
Simultaneous or Sequential?
Bilateral cochlear implantation has been found to offer significant benefits to children with severe-to-profound hearing impairment. Where a single implant can enable a child to hear, two implanted simultaneously in a young child can give the child the gifts of song and music, and can significantly improve his or her ability to interact socially and to hear incidental sounds such as those in the back seat of a car, on the street, or on the playground. In a recent article in The Laryngoscope (2009;119:2444–2448), Dr. Papsin and coauthors demonstrated that simultaneous bilateral implantation in children was safe and effective in a series of 50 cases.
“Any parent will tell you that [the children] pick up stuff so much quicker [with bilateral simultaneous implants],” he said in an interview with ENT Today. “I have a video of a child actually singing the ABCs in tune.”
Dr. Papsin said bilateral implants are the standard of care in his hospital. “I think the key is if you have a funding structure that supports it, if you have a surgical team that can perform it, if you have an audiologic diagnosis that is dependable and if you have family who are willing to undergo that procedure, then I can’t imagine why you wouldn’t go for simultaneous bilateral or a bilateral implant,” he said.
Audie Woolley, MD, said studies show better sound localization and speech perception with bilateral implants. “They’re showing overall better listening skills, both for children in the classroom and in social situations,” said Dr. Woolley, associate clinical professor of otolaryngology and pediatrics at Children’s Hospital of Alabama and the University of Alabama Birmingham School of Medicine, where he is also medical director of the Pediatric Cochlear Implant Program.
Dr. Woolley recommends either simultaneous implants or bilateral implants with a limited interstage interval for a majority of his patients. “The cost is going to be much less if you do simultaneous because you’re going to have one OR [operating room] time. You’re not going to have two anesthesia charges. You’re not going to have two hospitalizations,” he explained.
At Children’s Hospital of Philadelphia, the standard procedure is to implant bilateral cochlea sequentially. “The main reason for that approach is that we like to verify that the children are responding well to the first implant, and that they’re getting good benefit initially, before proceeding with the second,” explains John Germiller, MD, assistant professor of otorhinolaryngology at the University of Pennsylvania/Children’s Hospital of Philadelphia, where he is also director of clinical research for otolaryngology.
As well, Dr. Germiller said that there may simply be no significant medical advantage to doing two at once: “So far there are not overwhelming data that prove that if you do it simultaneously it’s better than if you do it with a short delay…meaning under a year between the two, and ideally, under six months.”
There may be some absolute indications for bilateral implantation, according to Craig Buchman, MD, professor and chief of neurotology and skull-based surgery and medical director of the Carolina Children’s Communicative Disorders Program (CCCDP) at the University of North Carolina, Chapel Hill. “If a child is deafened from meningitis and they have ongoing cochlear ossification, they probably should get bilateral implants acutely or with a very limited inter-device interval,” he said. “If a child has progressive or complete visual loss, bilateral implants are really strongly indicated for the sound localization issues. If a child is blind, I believe that bilateral implants should be best practice.”
Some clinicians may be concerned by the possibility of increased complication rates with bilateral implants. “There’s no difference in complications with one versus two,” Dr. Woolley said. “There’s no difference with hospital length of stay. There’s no difference in the amount of pain or discomfort or the amount of nausea. So, for us, the only difference is a little bit of increase in length of surgery, obviously, because you’re doing two ears instead of one.”
The Case for Unilateral Implantation
A number of factors can influence the decision to implant a single cochlea versus two. One instance in which unilateral implantation would be seriously considered is the child who is profoundly hearing impaired in one ear but has residual hearing in the second ear. “If a child has a lot of residual hearing, we may err on the side of doing an implant on one side and then use a hearing aid in the contralateral ear for a period of time to see how they do,” Dr. Buchman said. “As you start adding in more residual hearing, the decision making becomes dramatically more complicated because the issue becomes whether the child can gain benefit from a second-side hearing aid versus a cochlear implant,” he explained. “I don’t think that we know all the answers to how much hearing is considered good enough to save.”
Another case for unilateral implantation is the child with profound developmental delay. “Two contraindications in our program for simultaneous cochlear implantation would be abnormal cochlear anatomy or substantial developmental delay which would make rehabilitation difficult,” Dr. Woolley said.
Very young age of the patient and parental preference may also be reasons for unilateral implantation. “Bilateral surgery in a child under one year of age is a lot of surgery,” Dr. Buchman said. “Some families are not bought into the entire concept at that age. In less than a year, they’ve had a new baby, their baby is now thought to be severely hearing impaired…and they’re still in the process of figuring it out.”
According to Dr. Papsin, when factors outside of medicine and pure clinical benefit to the patient are considered, the argument seems to come down on the side of a single unilateral implant. The benefit to the patient of the first implant is significantly greater than that of the second. The first enables a deaf person to hear. The second provides qualitative improvements in the efficacy of this newfound hearing. If the two implants are done sequentially, doubling all the costs associated with a single procedure, a single cochlear implant is significantly more cost effective than two.
“The reason why is because the first one shows so much effectiveness [that] it’s close to near normal on the scales that we use. So, adding a second doesn’t seem to be cost effective,” Dr. Papsin said.
The Centers for Medicare and Medicaid Services (CMS) do reimburse for both unilateral and bilateral cochlear implants, under very specific conditions. According to the CMS website, “Effective for services performed on or after April 4, 2005, cochlear implantation may be covered for treatment of bilateral pre- or post-linguistic, sensorineural, moderate-to-profound hearing loss in individuals who demonstrate limited benefit from amplification.”
Despite the CMS policy, cost and reimbursement are among the main reasons children receive a single implant or that they receive two sequentially. In many cases, “it’s not favorable to the hospital to have a bilateral case because they may not get compensated very much for the second surgery,” Dr. Germiller said.