University of Miami Miller School of Medicine researchers have initiated enrollment for two National Institutes of Health (NIH)-funded clinical trials looking at how devices that cool vulnerable parts of the ear might safely prevent hearing loss.

One study investigates cochlear implant patients, the other, firefighters, whose job-related exposure to loud noise is a known risk for hearing loss.

Miller School otolaryngology faculty are collaborating on the studies with University of Miami College of Engineering Professor Suhrud Rajguru, Ph.D.

“Hypothermia therapy has been shown to be very effective in neural preservation and Dr. Rajguru, with his team, have applied this regimen to preservation of residual natural hearing during cochlear implantation surgery,” said Fred Telischi M.D., the James R. Chandler Chair of the Department of Otolaryngology-Head and Neck Surgery and professor of otolaryngology, neurological surgery and biomedical engineering at the Miller School. “Starting these first-in-human clinical trials is as exciting as it gets for translational research and biomedical innovation. If it works as well in patients as it did in the preclinical trials, we have a game-changing intervention with minimal side effects.”

Cooling Therapy to Prevent Hearing Loss

The outcomes of these trials could result in the first non-drug option that preserves hearing simply by therapeutically cooling ears. But while the concept sounds simple, the technology took years to develop. Dr. Rajguru holds patents on hypothermia technologies to preserve hearing and is founder and chief scientific officer of RestorEar Devices, LLC. The company is recipient and lead for NIH Small Business Innovation Research (SBIR) grants that funded these studies.

“There are many trials going on around the country for preserving residual hearing, but these are the only studies involving temperature manipulation,” Dr. Rajguru said. “Other trials involve drugs or require people to use certain implant types, in the case of cochlear implantation. Our technology is based on the therapeutic potential of ice and it will work with any cochlear implant on the market.”

Cooling During Cochlear Implant Surgery

Cochlear implantation is an important treatment option for people who have some hearing, according to Michael Hoffer, M.D., professor of otolaryngology and neurological surgery at the Miller School. Dr. Hoffer, Dr. Telischi and Simon Angeli, M.D., director of the UHealth Ear Institute and professor of clinical otolaryngology and neurosurgery at the Miller School, will perform cochlear implant surgery in this trial.

“Over time we’ve been implanting individuals with more and more residual hearing and have found overall improvements in these people’s ability to hear, understand and speak when the implants are on,” Dr. Hoffer said. “However, the limited hearing that they came into the surgery with may be lost. The hope is that by using this technology to cool the cochlea from the ear canal during surgery, patients will retain the hearing they had and have functioning cochlear implants in the long term.”

The cochlear implant study has safety and efficacy arms. Six patients will participate in the safety arm to test hypothermia’s safety during and after cochlear implant surgery. The efficacy arm will enroll 48 patients to determine if the applied hypothermia preserves residual hearing, according to study principal investigator Sandra Prentiss, Ph.D, CCC-A, associate professor of otolaryngology at the Miller School.

“This groundbreaking, first-in-humans trial represents a remarkable step in translating research into clinical practice,” Dr. Prentiss said. “This technique of hypothermia will be a way to control some of the inflammation and irritation patients may experience during surgery for a better chance of preserving residual hearing and ultimately optimizing cochlear implant outcomes.”

Firefighters and Hearing Loss

Miller School researchers will use a different device in the firefighter study.

“To help prevent hearing loss, we designed gel packs that deliver therapeutic levels of cooling on the temple bone right behind the ear through surface contact,” Dr. Raiguru said.

The device, he said, fits much like over-the-ear headphones, but without covering the ears.

According to study principal investigator Hillary Snapp, Au.D., Ph.D., chief of audiology and professor of clinical otolaryngology at the Miller School, the study will provide critical information on the effectiveness of hypothermia in at-risk populations. Additionally, the device is designed for general use, opening the door to benefit the broader population.

The research team plans to enroll more than 120 firefighters. Comparisons will be made between groups who do and do not receive hypothermia following occupational noise exposure.

“Our team will go to fire stations and measure study participants’ hearing to determine the safety and efficacy of hypothermia as a therapeutic for noise-induced hearing loss,” Dr. Smapp said. “In addition to monitoring hearing, we will also study device use patterns and behavioral intent.”

Drs. Snapp and Rajguru have published studies on the dangers of noise exposure and risk of hearing loss in firefighters.

“This latest research adds to the Miller School’s long and strong history of collaboration with the fire service to eradicate work-related disease and disability,” Dr. Snapp said.

The model that has applicability for use in all types of ear trauma, including blasts, explosives and gun shots to which members of the military and police are exposed, added Dr. Hoffer.

Article originally appeared on U of Miami Miller School of Medicine.