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written by: Alice Ferng
More than 200 million people worldwide, including approximately 8.5 million Americans, suffer from Peripheral Artery Disease (PAD). In the U.S. and Europe, PAD is responsible for around 240,000 amputations every year. Nearly a quarter of patients die within 30 days and almost half within a year of their limb amputation. With the number of diabetic patients increasing annually, a group at high risk for arterial blockages, safer, faster, more effective, and less expensive treatment options have never been as important. DABRA is an innovative new technology from Ra Medical Systems that can combat the growing number of diabetic amputations in our country.
Ra Medical’s DABRA technology for PAD treatment has recently received FDA market clearance. We bring to you an exclusive interview with Dean Irwin, CEO of Ra Medical Systems. To give you a quick biography of Dean, he was the VP of Research, Development and Engineering for PhotoMedex, where he developed laser systems for cardiovascular surgery and dermatology. He pioneered the XTRAC – the first excimer laser for dermatology – in conjunction with Harvard Medical School and Wellman Center of PhotoMedicine. He has published numerous engineering and scientific papers and consulted for the Plasma Research Center at MIT and the Intel Corporation. Dean has been issued eight patents in the field of UV light and phototherapy, four patents for advanced display technologies, and has patents pending for methods, devices, and catheters for cardiovascular applications.
Alice Ferng, Medgadget: Tell me about Ra Medical systems and your DABRA technology.
Dean Irwin, CEO, Ra Medical Systems: Back in late 1980s and early 1990s, several groups, one of which I was involved with here in California, set out to commercialize excimer laser technologies. We felt that just like Lasik for eye surgery, lasers could be used to clear out vessel blockages without a lot of trauma. At this time, excimer laser technologies were fairly new, large, and expensive, and the only technology we had available to us to get the laser energy inside the body where it was needed was fiber optic technology. Even back then, that was in its infancy as well. So several companies did launch systems – one be Spectranetics, and other Advanced Interventional Systems. With my particular technology, I decided that fiber optics wasn’t going to be enough to deliver on the promise of cleaning out these blockages without the trauma. I set out to develop an excimer laser to treat dermatological disorders.
I started Ra Medical Systems back in 2002 with Melissa Burstein. And we knew that one of the possibilities was to commercialize the laser for treating atherosclerotic disease or blockages in the arteries. But we decided to tackle it from a different view: instead of making a fiber optic bundle, we decided to use a liquid to transmit the energy. We encased a liquid in a small plastic tube and we used the liquid as the transmission media to get the laser energy from the laser to the blockage. We were successful and starting prototyping in 2007, and by 2012, we treated our first patient. We filed with the FDA in 2014. Here in 2017, we have now received FDA clearance for the product. We have now treated hundreds of patients with lots of fantastic success stories.
Medgadget: What is your background and what got you interested in peripheral artery disease treatments?
Ra Medical Systems: I come from the physics world where I was studying thermonuclear fusion back in the 1970’s. I spent a little bit of time at MIT, and came out to California in the early 1980’s working for General Atomics on a thermonuclear research program supported by the U.S. Department of Energy.
Medgadget: How did you get involved with this type of technology and application?
Ra Medical Systems: Of course lasers and mazers was what I was working on with fusion research, and that ultimately led me to start building lasers for medical applications. I have been working with lasers and electro-optics ever since 1978.
While I did not have an initial interest in peripheral artery disease, when I was approached by a group of individuals who told me about how PAD was one of the leading diseases in the world that could be easily treatable with lasers I became very interested in this application. I saw that this was a problem that was in need of a solution, and I thought that the excimer laser was ideally suited to clean out these blockages and that the real challenge was “how do we get the energy there?” This turned out to be quite the challenge.
Medgadget: While peripheral artery disease is your current use case, what are some other conditions you plan to tackle in the future?
Ra Medical Systems: Peripheral artery disease is what we are starting on, and we are moving on to coronary artery disease next. The peripheral artery disease affects some 10 million Americans today. It is underdiagnosed and begins by the symptoms of pain and claudication of the legs, gradually becoming more severe and ultimately leading to wounds that won’t heal and gangrene or amputation. There are around 150,000 amputations every year due to peripheral artery disease.
We had a great case recently where one of our physicians used the DABRA catheter to treat a patient who had already attempted treatment twice at a major hospital in San Diego. They told him that he was never going to play tennis again and may have to ultimately undergo amputation. With the DABRA catheter, we were able to re-cannalize and open up the blockages in his leg. Just one week after the treatment, he was back on the tennis courts. It’s quite a miraculous story. The DABRA is able to remove these blockages in patients where other technologies are unable to. We also believe that DABRA contributes to better patency, where the blocked arteries will stay open for even longer than other technologies.
Medgadget: It’s very impressive what DABRA is able to accomplish. What makes it so successful compared to other products on the market? What advantages and disadvantages does it have?
Ra Medical Systems: We really thought that there were four problems that interventional cardiologists, vascular surgeons, and interventional radiologists were facing. The first one was safety. A lot of these technologies use metal burrs or cutting blades that go into the arteries to carve out the blockages. Of course, that potentially causes damage to the vessels as well. As a result, safety was our number one priority. So far to date, the DABRA catheter does not have a single adverse event, so we have a perfect safety record. Sadly, a lot of these technologies are very difficult to use, requiring air, special fluids, and spinning to keep the devices cool and functioning. They are often hard to set up, and so another problem was to make sure our device was easy to set up and use. Third, a lot of these devices only tackle one type of blockage. That is, they could not cross a complete blockage and could only work on hard calcium as opposed to atheroma or thrombus, and multiple devices are needed to remove different types of blockages. Of course, a balloon would only compress the blockage to the side of the arteries. In order to use the balloon for these blockages, of course you had to first get across these blockages. In many patients, they have what is known as a chronic total occlusion, where they cannot get anything cross it. With our lasers, we can operate across all 4 layers of plaque. The fourth final piece to this puzzle that we have is that we are much more economical. We cost about a half to a third of what competing technologies do. That’s important because a lot of patients and physicians do not have access to many of these expensive technologies.
Medgadget: How large is the DABRA technology and how easy or difficult is it to set up in a clinical environment?
Ra Medical Systems: The laser is about the size of an airline food cart, and it can be plugged right into the wall. The DABRA catheter is removed from a sterile pouch, and inserted into a cannula so that the artery blockage can be accessed through the arterial vascular system. It is set up such that the physician has very little they need to do, since the laser can be set up outside of the sterile field, and then the sterile catheter can be used by the physician once it is ready.
Medgadget: Can you give me some technical details about the laser and physics behind the technology for those of us who are curious about these things?
Ra Medical Systems: The laser is a 308 nm laser, that produces up to 5W of power. Xenon chloride excimer laser. This is a wavelength that has even energy to break bonds through photochemical ablation, but still not so low that it cannot be transmitted through other mediums. The physician has control over the energy and repetition rate, typically the laser operates at 70 Hz, but the physician can dial it down to 20 Hz or up to 80 Hz. Usually no adjustments have to be made, and we operate at the default frequency of 70 Hz, which seems to be ideal. The energy starts off at a minimum of 10-12 mJoules per square mm, which is enough to ablate these materials. The physician has the option to increase this to 15-16 mJ/mm2. This is quite rare also, and is only increased for very hard calcium blockages.
Medgadget: How long does the treatment take?
Ra Medical Systems: The laser can cut the plaque up to 1 cm/sec, so the procedure usually takes just a few minutes – that is, the laser part of the procedure. For example, the whole procedure I did the other day with a physician took just 22 minutes. Since we are not cutting the patients open, they literally walk out the same day. In many cases, they cannot walk in on their own, but are able to walk out. It is really rewarding.
Medgadget: Is Ra Medical planning on developing other products with this laser technology?
Ra Medical Systems: We developed the laser platform, and our company also develops a dermatological laser. We use essentially the same platform for vascular and dermatological applications. The mechanism of action is a little difference for the other application, but the basics of photochemical ablation is fundamental to both.