Restoring Hearing Loss through Scientific Advancement
May 18, 2023
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Dr. Dan Simon (Host): Hello, everyone. My name is Dr. Daniel Simon. I am your host of the Science at UH Podcast, sponsored by the University Hospital's Research and Education Institute. This podcast series feature University Hospital's cutting-edge research and innovations. Thank you for listening to another episode.
Today, I am happy to be joined by guest, Dr. Alejandro Rivas, Division Chief of Otology and Neuro-Otology and Director of the Cochlear Implant Program here at University Hospitals. He is also a professor and the Richard W. and Patricia R. Pogue Chair in Auditory Surgery and Hearing Sciences at Case Western University School of Medicine. Dr. Rivas is a renowned otolaryngologist and pioneer of endoscopic ear surgery. His research focuses on various conditions and treatments such as endoscopic ear surgery, cochlear implantation and single-sided deafness. Welcome, Alejandro.
Dr. Alejandro Rivas: Dr. Simon, thank you very much for having me. It's a pleasure to be here and to talk a little bit about what passions me.
Dr. Dan Simon: So, tell me a bit about yourself. Where did you grow up and train? What inspired you to be a physician scientist? And what brought you here to UH?
Dr. Alejandro Rivas: Yeah. So, I'm originally Colombian. I was born and raised in Bogota, Colombia. That's where I did medical school. My father is a neuro-otologist. So at a very early age, I started to see how he would teach people from around South America how to do ear surgery. And that was ingrained into my brain. And so shortly after I came to the States with the idea that I wanted to be in a country and at a place where we could advance sciences. Colombia has great medical systems that is top of the line, but the research is lacking, and the resources for research is lacking. So, that would inspire me to seek training somewhere else.
And so, I did a research fellowship at Johns Hopkins for a few years. Subsequently did my internship at USC, otolaryngology residency at Johns Hopkins again, then, I moved to Nashville where I did a fellowship in Otology and Neuro-Otology at Vanderbilt University at the otology service there. And then, I stayed there for 13 years. I was there as a faculty until UH recruited me to come to Cleveland. And one of the reasons why I wanted to be here is because it's a tremendous opportunity. What I've always been seeking is the same. It's an institution where I can expand the field where I can help contribute to the advancements of science. And there was always a mentor that told me that if you treat a patient, you treat one patient, but if you do research and if you write what your results are and the research that you do, then you'll impact thousands of people with some of those findings. So, that's part of the story.
Dr. Dan Simon: Well, we're so lucky to have you. I think it obviously doesn't hurt to have a CEO who also likes cochlear implants. So, we're so glad that Cliff and Dr. Nicole Maronian got involved in recruiting you here. So, you are considered one of the pioneers of endoscopic ear surgery in the United States and the globe. Your research endeavors of endoscopic ear surgery and hearing loss target the use of the least invasive and less morbid management options to improve auditory outcomes of hearing impaired patients. What are the current challenges of our existing healthcare model with regards to cochlear implants and how can we improve the value of cochlear implementation in healthcare today?
Dr. Alejandro Rivas: The impact of hearing loss is something that has always been an interest of mine. And the fact is that if you look at around the globe, there's 466 million people worldwide with disabling hearing loss. And of out of those, you have 34 million that are children. And if we look at some of those statistics, for example, you know, that one out of three people began experiencing hearing loss between the ages of 65 and 74 years old. Ten thousand people turn 65 every day. So, that creates a really large population of patients and population needing hearing health. By 2050, we know that over 900 million people will have disabling hearing loss. And we also know that the unaddressed cost globally is over around 750 billion.
And so with those types of statistics, we need to be able to procure better hearing options for our patients. And when we look at the coverage or the impact that cochlear implants currently have, the penetrance of cochlear implants in the United States and the world, depending on the region, is not better than 6% to 8%. And so, as you can see with those types of statistics, there's challenges, but more than anything, there's a great opportunity to be able to impact our community and impact our region. And so, that has been some of the efforts that we've been having here at University Hospitals since my arrival.
Dr. Dan Simon: So in the US, the majority of cochlear implant procedures are performed under general anesthesia. However, there are few select cochlear implant centers in the country that now offer the procedure using light sedation and local anesthesia instead of general anesthesia. UH is the only center in the region performing cochlear implant surgery in this way. Is it safe to implant cochlear under local anesthesia? And how does it benefit the elderly population?
Dr. Alejandro Rivas: So, yes, it is very safe. Cochlear implants is a two-hour to two-hour and a half procedure, and it is an outpatient procedure. And so, particularly with patients who are elderly, they have comorbidities that might prevent them from getting a cochlear implant. We do know that elderly patients have much more difficulty with general anesthesia and recovering from general anesthesia from a cognitive perspective. And with that in mind, being able to do a cochlear implant under local or light sedation is ideal, because, number one, we can make the case a little bit shorter because we reduce the amount of time that takes putting a patient to sleep and waking them up. So, that reduces time of surgery itself. In the other portion, it's something that with the current anesthetic procedures and prepping and having a good communication with your anesthesia partners, you can make your patients very comfortable, and we've been very successful at it. For those, patients that are willing to get this done without general anesthesia.
Dr. Dan Simon: So, one of the things I think that's a little confusing for a cardiologist like me, you know, I don't have a lot of expertise in this area. I thought cochlear implants were predominantly for children. And you're saying that 10,000 people turning 65 every day, and hearing loss in that group is the largest and fastest growing. How do you determine whether a patient would benefit from a traditional hearing aid versus a cochlear implant? What is the sign that you need something more than a regular hearing aid?
Dr. Alejandro Rivas: I can describe those signs in two terms. If I give you the scientific measure, we can talk about percentages. Just like, for example, vision when we talk about vision, you have a 20/20 vision. For consideration of a cochlear implant, what we're trying to promote is the concept of 60/60, 60% of speech understanding or 60% of your average tone hearing. And so, those are measurements that you can get under any type of hearing test. And if you are worse than those numbers, 60/60, that means that you very well be a candidate for a cochlear implant. You have to do more studies and determine the candidacy in a better manner with x-rays, with CT scans, MRIs, and a formal cochlear implant evaluation, but to determine is the 60/60 mark. Now, if I put it in a little bit easier terms, it also becomes when your hearing aid is not providing you enough benefit and you're struggling with a hearing aid. And the other portion of it is that throughout the last 10 to 15 years, there has been an improvement and increase in the indications of implantation. It used to be that we would implant patients with complete deafness. Now, we don't. Now, we are actually able to preserve some of the residual hearing, some of the hearing that even though is not great hearing, is still hearing and is still useful. Some of that residual hearing we actually can preserve. So, we're able to offer cochlear implants on patients with better hearing. And guess what? Those patients who have better hearing actually do better with cochlear implants because they have more substrate. They have more neuronal substrate to utilize to make an implant efficient.
On the other hand, it used to be that cochlear implants could only be implanted on patients with hearing loss in both ears. Now, from a lot of our research, we know that patients with single-sided deafness, meaning deafness in one ear and normal hearing on another ear, they can do fantastic with a cochlear implant and much better than with hearing aids. Because when you have a complete deafness in one ear, a hearing aid won't be useful. You can send the sound to the other ear, to a Bluetooth device, but you're not going to be able to stimulate the lost organ.
And so, there's two conditions that are very important for implantation. One is hearing and noise. The world is noisy, the world is not quiet. And so if you go to a restaurant, if you even walk down the hospital, you'll see that there's a lot of noise all around. And unfortunately, people with one hearing ear cannot, you need two ears to be able to suppress the noise.
Dr. Dan Simon: Wow.
Dr. Alejandro Rivas: And so, it's very important for patients to be able to hear noise, and the other one is know where the sound is coming from. To be able to know where a sound is coming, you need to have two ears. And so, cochlear implants for single-sided deafness, there is a magnificent opportunity to restore their hearing noise as well as sound localization.
Dr. Dan Simon: That's terrific. So, you're the principal investigator for several trials for hearing preservation. Can you tell us about some of these research studies and how these findings could impact patient care?
Dr. Alejandro Rivas: Absolutely. Hearing preservation is very important because as you know, and as I mentioned earlier, the earlier you implant patients with residual hearing, the better the outcomes. If you implant a patient that is in their 70s, they do worse than patients that are in their 65s, 55s and 50s. So, the earliest you implant patients, the better they do. So if you take that into account, implanting patients at an early age means that they might have a little bit more substrate and also a little better hearing. And you want to use that better hearing. We know that if we implant patients with residual hearing and we preserve that hearing, we can improve their speech understanding by 20 percentile points, which is huge. And so with that in mind, the studies that we're doing are aiming and demonstrating that using specific electrodes that can send steroids inside the cochlea will prevent inflammation, prevent scarring, and preserve that residual hearing. And so, that is one of the studies that we started that's called the DE study, dexamethasone drug-eluting electrode that we use for those purposes. It's a multi-institutional study, that it's global, not only UH and then not only in the US either, but global. And we are close to finishing collecting data and enrolling patients on that one.
The second study is looking at a regular type of electrode called the 632 and how that electrode can also preserve hearing. And so, on that particular electrode, there's this belief that there's two types of electrodes that we put in. One that is a straight array, the other one is a pre-curve array, and it has always been thought that the best electrode to preserve hearing is a straight array. And although that is true, that electrode stays away from where the neurons of the cochlear are. So, the nice thing about the pre-curve array is that it's closer to those neurons. And so, you want to be closer to those neurons as possible because that improves speech understanding. But if you do that, you're at a higher risk of sacrificing residual hearing. But with this particular electrode, the 632, at least us at University Hospitals, we've been able to demonstrate that that preservation is achievable. So now, we're doing the preliminary studies, and this is a clinical trial looking at those hearing preservation results with that particular electrode. It really gives you the best of both worlds, better speech understanding and better residual hearing.
Dr. Dan Simon: Wow, that's really cool. So in addition to implants directed to the inner ear, surgeons can also use another technology for bone conduction. While the device being currently studied is FDA cleared for children 12 and under, it is not cleared for children five to 11. You are leading a clinical trial for an implantable hearing device in this age group who have been born with hearing loss that may be caused by craniofacial abnormalities. In fact, UH became the first site in the nation to kick off the trial. Can you tell us about this study? It sounds very exciting for a very important age group.
Dr. Alejandro Rivas: Absolutely. So, patients with craniofacial abnormalities or conductive hearing loss, many patients with microtia, little ears or atresia, kids that were born without an ear canal, have a baseline conductive hearing loss. And so, this is different than a cochlear implant. Bone conduction implants are implants that you put on the skull and through the bone, it transmits sound all the way into the cochlea. And so, traditionally, those bone conduction implants that are called passive, they were done through a little screw that you would put through the skin and attached to the bone. And then, you had a processor attached to it.
So over the last five to seven years, there has been a movement from, instead of using a passive bone conduction implant, an active one. An active means that instead of putting a little screw on the skull, you put a magnet and that magnet goes completely underneath the skin. So that is important, particularly in kids with craniofacial abnormalities because those abutments, those screws used, the profile of it was really far out the skull, and that kids would bump it, it would fall, it's less appealing. Particularly for girls, it's not a big problem because if they have long hair, they can cover it. But for boys, it's a bigger problem because you can see that screw coming out of the skull. And so, it was very important to be able to adapt this technology to children earlier than 11 years old. For example, kids with microtias are being reconstructed. The ideal age can vary between four to eight years old, and we would have to wait until all of that reconstruction is done until we can put this type of implant. And so, we don't want to wait until 11 years old for those patients to benefit from a bone conduction implant. So, this is another study that we're doing, using this OCI device in age five to 11. We finished enrolling three weeks ago. And so now, we're going to be doing the follow-up. It goes up to six months to a year after implantation. And we'll have some results hopefully at that time.
Dr. Dan Simon: Dr. Rivas, thank you for taking the time to speak with us today. It's really been a great learning experience for me and I'm sure for our listeners as well. For those who are interested in learning more about research at University Hospitals, please visit uhhospitals.org.