Physicians evaluate upper airway stimulation therapy for sleep apnea in adolescent patients with Down syndrome
Story by Suzanne Day. Photo by Garyfallia Pagonis.
From the Fall 2015 issue of Harvard Otolaryngology magazine. For inquiries or to be added to our mailing list, please contact Suzanne_Day@meei.harvard.edu.
Patients with Down syndrome and severe obstructive sleep apnea present unique challenges for physicians. Key characteristics of the anatomy in this population, such as larger tongues that fall back in the mouth during REM cycles, can obstruct the airway during sleep, and sensitivity to the feeling of a mask blowing air onto the face makes the traditional therapy for obstructive sleep apnea, a CPAP machine, a nightmare for these patients.
Without any favorable options to turn to and the threat of cardiovascular issues like high blood pressure and heart disease if the sleep apnea is left untreated, physicians and patients’ families are sometimes left with the difficult decision to resort to life-altering tracheostomies, if the obstruction is severe to the point of not being safe.
When Christopher J. Hartnick, M.D., Division Chief of Pediatric Otolaryngology at Massachusetts Eye and Ear, first encountered a 2014 study published in the New England Journal of Medicine of a large multicenter clinical trial assessing the efficacy of the hypoglossal nerve stimulator — a new technology that had recently gained momentum as an alterative to CPAP therapy — in adult patients with severe obstructive sleep apnea, he saw a unique opportunity to help pediatric patients with Down syndrome and severe sleep apnea.
“We believed that the technology had a lot of potential to be applied to this population, because it is exactly that area – the large tongue base – that, most often, is causing the sleep apnea,” Dr. Hartnick said. “The most compelling thing about it was the potential to help a population for which there are often no good treatments available.”
By stimulating a branch of nerves in the upper airway, the hypoglossal nerve stimulator causes the tongue to move forward and out of the airway during sleep. In surgery, a cuff is placed around selective branches of the nerve, and a wire is tunneled down to a receiver in the chest, and another to a sensor below the ribs. The sensor detects breathing and sends up a signal to the stimulator cuff, which sets the whole process into motion.
Patients and their physicians can program the technology to turn on at a certain time each night, approximately half an hour after the child goes to sleep.
The implant is powered by a battery that needs to be changed, which involves a minor follow-up procedure every 10-15 years. Patients with the implant are restricted from participating in MRI studies.
Keenly interesting in bringing the technology to this population, Dr. Hartnick and a team of physicians including Donald J. Keamy, Jr., M.D., John Dobrowski M.D., and Gillian Diercks, M.D., of Mass. Eye and Ear, and Thomas B. Kinane, M.D., Allison T. Schwartz, M.D., and Brian G. Skotko, M.D., of Mass General, began an FDA-approved pilot study evaluating the safety and efficacy of the use of the hypoglossal nerve stimulator in adolescents (ages 12 to 21 years) with Down syndrome and severe obstructive sleep apnea. They received a grant from Inspire Medical Systems, Inc., in support of the study.
The team performed the first pediatric implantation in the United States on April 8, 2015. Ryan J. Soose, M.D., a sleep surgeon from the University of Pittsburgh Medical Center and author from the study published in the New England Journal of Medicine, traveled to Mass. Eye and Ear for the surgery.
“I think one of the advantages of academic medicine is that we work together,” Dr. Hartnick said. “Ryan is an adult sleep doctor, but he was very interested in helping us by sharing what lessons he had learned and exploring the opportunity to extend the technology to this population.”
One additional patient has been implanted since the first surgery was performed, and Mass. Eye and Ear has the capacity to enroll four additional subjects. Subjects in the clinical trial are being followed closely through office visits and sleep studies to thoroughly assess safety of the treatment.
The first subject’s sleep study results showed a decrease of obstructive sleep apnea symptoms from an apnea hypopnea index score above 40 to below 10, and the child has subsequently been decannulated with positive results.
“At the end of this summer, he was able to go swimming for the first time,” Dr. Hartnick said. “He appears to be living comfortably without a trach.”
Dr. Hartnick and the team are looking at many different factors to understand the safety of the device. They want to ensure that the implant is well tolerated and that patients and families will comply with their treatment plan.
“Our first child doesn’t seem to notice it there, but we are wondering if the processor is bothersome,” Dr. Hartnick said. “Will they pick or scratch at it? Or, will they wake up suddenly, feel it, and then be scared to use it again?”
“Though this technology has been used successfully in adults, this situation is completely different given the involvement and dependency on the parent. And when these adolescents become adults, will they still comply? These are just some things we have to follow.
As they continue to identify and enroll subjects in the trial, Dr. Hartnick and the team are gaining valuable experience in surgical technique, and also in acclimating families to the new technology.
Future goals would be to expand the study to a multicenter trial.
“Before this technology came along, we had a population of kids who – even after removing their tonsils, adenoids and lingual tonsils – still needed treatment for severe sleep apnea. And if they couldn’t tolerate a CPAP, we were faced with this terrible choice of whether to perform a tracheostomy or to just wait to see if they developed a heart problem,” Dr. Hartnick said. “If this works out, it will be a game changer for those situations.”