A recent news report out of the Bay Area announced that a clinical trial of the Magnetic Apnea Prevention (MAGNAP) device for obstructive sleep apnea (OSA) treatment has begun at University of California San Francisco Medical Center. The initial response to this report indicates that there is an incredible amount of interest from the sleep apnea community in this potential alternative to CPAP for sleep apnea. But, if eventually approved by the FDA for sleep apnea treatment, would this be a good option for you? In this article, I'll explore the forces, both attractive and repulsive, that this treatment option is likely to generate.
In the Beginning, There Was Magnet
Using magnets to treat sleep apnea is not a new concept. The earliest reference to a magnetized OSA treatment device in the medical literature is a 1998 study entitled, "A Magnetic Appliance for Treatment of Snoring Patients With and Without Obstructive Sleep Apnea," by Berhnold and Bondemark. In this study, the researchers created an oral appliance with magnets embedded to pull the mandible forward, thereby mechanically widening the retro-lingual (behind the tongue) space and opening the posterior upper airway. Subjects had a sleep apnea test without the device and then another one with it, and it did show a significant benefit in treating sleep apnea. This idea never took off, probably because dentists figured out that they could achieve the same result of advancing the mandible without the magnets by pushing the jaw forward with some extra plastic.
Enter MAGNAP: the "Sleep Apnea Magnet Solution"
The inception of MAGNAP appears to date back to 2008, when Ethicon, Inc filed a patent for "Magnetic implants for treating obstructive sleep apnea and methods therefor." Below is an image from the patent application.
As you can see, the original iteration involved having a "T" shaped magnet implanted in the tongue - ouch! Thankfully for potential patients, the application left the door open for several variations on the same theme. The final iteration involves surgically attaching a magnet to the hyoid bone. Where is the hyoid bone, you ask? See the X-ray below; the hyoid is circled in yellow:
How Does the MAGNAP Work?
The concept is elegant and simple. A surgeon implants a magnetic device onto the hyoid bone. This would most likely be categorized as a "minimally invasive surgery" and could be done as an outpatient. When it's time for bed, you put on a collar that has another magnet. The attractive force between the magnets pulls the upper airway open and prevents airway collapse while you sleep. Proof of concept for the device was established in a 2012 human cadaver study. The next step in bringing the product to market is a clinical trial in living humans.
The Rubber Hits the Road
In 2016, the University of California San Francisco began enrolling patients in a small clinical trial entitled "Magnetic Apnea Prevention (MAGNAP) Device to Treat Obstructive Sleep Apnea: First-in-Human Study of Feasibility and Safety."
The inclusion criteria include:
- moderate-to-severe obstructive sleep apnea
- intolerant of continuous positive airway pressure (CPAP)
- ages 21-69
The estimated completion date for this research study is the end of 2020. If this pilot study is successful, Magnets-In-Me, MAGNAP's parent company, has stated that it will then embark on a larger clinical trial. In general, a successful large multi-center trial is needed before the FDA will consider approving a new medical device.
If you're interested in participating as a subject in the MAGNAP trial, you can find more information at clinicaltrials.gov.
What Are Potential MAGNAP Side Effects?
The recent press release about MAGNAP stated that "the only significant side effect [of the magnet implantation] has been temporary soreness on swallowing." Keep in mind that this is an invasive therapy and any surgery can lead to bleeding and infection.
A deeper dive into possible side effects indicates that a similar surgery, the "hyoid suspension," has been associated with the following risks:
neck seromas (subcutaneous fluid buildups)
transient dysphagia (temporary difficulty swallowing)
It is reasonable to suspect that the MAGNAP implantation surgery would also put you at risk for the same side effects.
Are There Other Downsides to MAGNAP?
Every Sleep Apnea Patient is Like a Snowflake
One major problem is that, depending on your individual anatomy, MAGNAP might not be effective for you. There are multiple areas where the upper airway can collapse, as depicted in the cartoon below. Patients can have collapse at one or a combination of these areas. Advancing the hyoid won't correct all of the possible areas of airway collapse.
Additionally, MAGNAP wouldn't be expected to work on other forms of sleep apnea besides pure obstructive sleep apnea. So if your sleep apnea test showed a component of any of the following, you're unlikely to respond completely to MAGNAP:
- primary or secondary central sleep apnea
- periodic breathing
- Cheyne Stokes respirations
- complex sleep apnea
You'll Never Get an MRI in This Town Again and Other Issues
The majority of people with implantable metallic medical devices will not be able to get an MRI. This is true for MAGNAP. So should you need to be evaluated for disorders like stroke, cancer, or back pain, you'll have to rely on older, less accurate imaging techniques like X-rays and CT scans.
Also, people with pacemakers, defibrillators, and other implanted medical devices that can be damaged by magnetic fields will likely not be candidates for the MAGNAP.
OSA Patients: Don't Hold Your Breath
Looking at the MAGNAP timeline thus far, it took four years from patent filing to the cadaver study, and another four years for the first small clinical trial to begin. If the current study stays on target and wraps up at the end of 2017, additional time will be needed to analyze and publish the data. Then, if (and that's a big if) positive results are found, a larger multi-center study will be needed. It is a lot harder to orchestrate a research study at multiple medical centers than just one hospital, so plan on waiting until next decade to be able to get treated with MAGNAP. And that's if everything goes smoothly!
The Laws of Attraction
It's normal for people to be attracted to a sleep apnea treatment that doesn't involve having to wear a mask and use a machine for the rest of their lives. A quick fix for OSA from a minor surgery sounds like a great idea! But buyer beware: many "quick fixes" for sleep apnea have come and gone over the years after failing to hold up to the scrutiny of medical science. There is a reason that CPAP is the gold-standard treatment for sleep apnea: no other treatment has come close to delivering the consistent results that CPAP has in multiple research studies.
There is cautious optimism that the MAGNAP system, in time, may become an option for some people who fail CPAP. Until we know the results of the ongoing trial, we'll have to prevent ourselves from getting sucked into the field of this new sleep apnea treatment. Singular Sleep will keep you updated on MAGNAP's progress.
Joseph Krainin, M.D., FAASM is the founder of Singular Sleep, the world's first online sleep center. He is a Fellow of the American Academy of Sleep Medicine and board-certified in both sleep medicine and neurology. He has been practicing medicine for over 10 years.