About 27-million people in North America and Europe alone suffer from peripheral arterial disease – or PAD. The disease limits blood flow to leg muscles, which can make it difficult to walk. Now, doctors are testing out a new way to treat the condition, and many patients are already benefiting.
Working out on a treadmill? No sweat now for 71-year-old Mary Hammond. But a few months ago...
"I be walking through the mall and I couldn't walk anymore," Mary Hammond told Ivanhoe.
Mary had peripheral arterial disease or PAD for short. It's caused by build-up in the artery walls.
"I thought I was just getting old and my veins were getting ugly in my feet and stuff like that," said Hammond.
Doctors inserted a flex stent into Hammond's leg. Like the name suggests, it's flexible and self-expanding. It won't close up, like other leg stents.
Charles Lambert, M.D., Ph.D., Medical Director of Florida Hospital Pepin Heart Institute and Dr. Kiran C Patel Research Institute, and Professor of Medicine at University of Florida, explained, "Based upon preliminary information, it looks like it's going to be a quantum leap forward in terms of treating those vessels long term."
The blood vessel before the flex stent has lots of clots. After the flex stent is in, the clots are cleared, and the artery is smoother.
"We hope to see much better long-term patency or it will stay open longer- because that's the principle problem in these vessels," explained Dr. Lambert.
Mary's problem seems to be solved.
"I can walk," said Hammond, "I can walk great. I can walk through the mall ten times and my legs wouldn't hurt me at all."
PAD can also be treated with exercise, medicines and bypass surgery in the legs. The flex stent is currently in the study phase right now.
Contributors to this news report include: Cyndy McGrath, Supervising Producer; Emily Maza Gleason, Field Producer; Travis Bell, Videographer; Kim Coley, News Assistant; Jamie Koczan, Editor.
BACKGROUND: Peripheral artery disease, or PAD, is a circulatory problem in which blood flow is reduced to the limbs due to narrowed arteries. Usually, the legs don't receive proper circulation, and pain can develop when walking. Atherosclerosis, or fatty build up in the artery walls is the most common cause of PAD; however some other less common causes are inflammation of blood vessels, injury to limbs, radiation exposure or abnormal anatomy of muscles and ligaments. Diagnosing PAD can occur through a physical exam, blood tests, or certain tests such as ankle-brachial index (ABI), in which the blood pressure in the arm is compared to the blood pressure in the ankle. An ultrasound can measure blood flow through the arteries, and an angiography injects a dye into the blood vessel to view blood flow through imaging techniques like X-Rays, magnetic resonance angiography (MRA), or computerized tomography angiography (CTA).
(Source: http://www.mayoclinic.org/diseases-conditions/peripheral-artery-disease)
PREVENTION/TREATMENT: Treating PAD is more so about preventing the disease or alleviating symptoms. Physical activity, maintaining low cholesterol levels, and avoiding smoking are the pinnacle of reducing the risk of PAD. In terms of drugs, a doctor may prescribe high blood pressure medications, cholesterol-lowering medications or blood clot medications. If a patient requires more extensive treatment, minimally invasive surgeries may be recommended. An angioplasty procedure threads a catheter through a blood vessel to the affected artery, and a small balloon at the tip inflates to open and stretch the artery. A tiny mesh cylinder, called a stent, may also be placed here to keep the artery open. Another procedure is a bypass, in which another vein is used to reroute blood around the closed artery.
(Source: http://www.heart.org/Conditions/PeripheralArteryDisease/Prevention-and-Treatment)
S.M.A.R.T.® FLEX STENT: As the latest innovation in self-expanding stents, the S.M.A.R.T.® Flex Stent has been created to optimize fracture resistance, meaning it can last long-term in the desired area. The stability of the stent allows it to stretch to the appropriate diameter once placed accurately, and not when it is initially deployed in the artery. Patients who have received this particular stent have shown a 58% overall improvement in walking distance with less pain. It is currently being evaluated in an open trial study to determine safety and effectiveness treating atherosclerosis. For more information on the trial, visit: http://www.clinicaltrials.gov/ct2/show/NCT01355406
(Sources: http://www.vasculardiseasemanagement.com/news/cordis-showcases-new-cardiovascular-innovations-europcr-2013, http://www.cordis.com/products/smart-control-iliac-stent-system, http://evtoday.com/2013/02/cordis-acquires-flexible-stenting-solutions)
FOR MORE INFORMATION ON THIS REPORT, PLEASE CONTACT:
Jennifer McVann
(813) 373-9505
If this story or any other Ivanhoe story has impacted your life or prompted you or someone you know to seek or change treatments, please let us know by contacting Marjorie Bekaert Thomas at mthomas@ivanhoe.com
Charles Lambert, M.D., Ph.D., Medical Director of Florida Hospital Pepin Heart Institute and Dr. Kiran C Patel Research Institute, and Professor of Medicine at University of Florida, talks about a new, more durable stent for those with peripheral arterial disease.
Interview conducted by Ivanhoe Broadcast News in October 2014.
How do you think the Flex-stent is going to change the way doctors treat this disease?
Dr. Lambert: The flex-stent is a fourth or fifth generation stent for the peripheral vasculature. It's always been a really hard area to treat with stents because of restenosis. It doesn't respond like the coronary or the heart vessels it's just very, very difficult. This stent is a variant of current designs in terms of its metallurgy, what it's made out of, and also its rigidity and flexibility. The design actually is very similar to some coronary stents but it's made to go in the peripheral vasculature where there's a really high restenosis rate.
This is going to really help a lot of patients who haven't been able find something to this point.
Dr. Lambert: Hopefully so. There aren't a lot of stents that you can use as far down the vessels in the legs as this one just because of the profile number one, and number two we hope to see much better long-term patency or it'll stay open longer because that's the principle problem in these vessels in the superficial femoral artery and the popliteal in particular.
Would you consider this a big breakthrough?
Dr. Lambert: We're going to have to see how the study goes. We want it to be a big breakthrough and probably based upon preliminary information it looks like it's going to be a quantum leap forward in terms of treating those vessels long-term.
For the people who have this disease how does this affect their daily life?
Dr. Lambert: Well most people that have peripheral arterial disease which is what this is for present with claudication; claudication is basically pain usually in your lower extremities when you walk, when there is a lack of blood flow to the muscle in your legs. Generally they'll present to their doctors at that time and have some tests done usually you start with noninvasive tests of pressures which if they're abnormal you have and angiogram. Then your choices are to treat with medicine or to go with more invasive therapies such as stents like the flex-stent. The stents are limited right now in terms of where you can put them and as I mentioned before their long-term patency. If it's successful when you treat one of these people they go from having very limited ambulation, being able to walk short distances to being able to walk as far as they can. Usually something else limits them like shortness of breath or something, being out of shape.
The idea is for it to stay open?
Dr. Lambert: Yes, forever.
Right now what's on the market now isn't staying open, is that the main thing?
Dr. Lambert: Right. We used to have this in the heart many, many years ago and we sort of solved that with drug eluding stents. Where there's a drug on the stent that is delivered to inhibit cell growth around the stent. In the legs that really hasn't worked as well as it has in the heart. Drugs have been tried, radiation has been tried, all kinds of stent designs. The other problem in the legs is you can push down on an artery in the leg, you can't reach into your chest and push a stent but if it's a collapsible stent, if it's a stainless steel stent that doesn't spring back open you can actually crush the stent. We don't use those types of stents anymore. The flex-stent you kind of get it from its name it's very flexible but it's also a self-expanding stent which stays open. You can't smash it with your finger or by trauma or bumping into something like you can a regular stainless steel stent.
Is this the only thing that can treat peripheral arterial disease?
Dr. Lambert: We treat it with very intensive drug therapy very similar to atherosclerosis anywhere else whether you've had a stroke or heart attack or peripheral vascular disease, peripheral arterial disease. We use exercise which is actually very effective for some patients; we use anticoagulants like antiplatelet drugs. There's also surgery for this, you can do bypass surgery in your legs. These days there are so many options with endovascular therapy which are balloons and stents, usually that's tried first unless the disease is so extensive that you really can't approach it with catheter-based therapy. In fact most vascular surgeons that we train these days they are trained just as well and as extensively with balloons and stents. It's kind of shifted away from surgery.
So far with the trial, what have you seen?
Dr. Lambert: We've seen that the system is very deliverable it which is one of the issues with getting way down especially toward the knee in the leg the vessels get very small, they get calcified, they're tiny and a lot of times it's very difficult to negotiate a stent down there. This stent is very negotiable. The other thing it allows you to do is partially deploy it and then recapture it and reposition it. If you're not exactly where you think you are with respect to the actual stenosis or the narrowing you can recapture the stent, pull it back or advance it and let it go again which is an advance over a lot of stent systems that are not recapturable.
Are you still taking patients to be in the trial?
Dr. Lambert: We're still taking patients with the other centers and will continue until we meet the enrollment targets.
This is pretty much the beginning phase of it?
Dr. Lambert: We're sort of in the middle third.
Is this geared toward patients who have tried everything else?
Dr. Lambert: It's geared not necessarily to last resort because we're using it as really standard-of-care. We will compare it to historical controls and other stents sort of in a cohort design. But they don't have to be at the end of their rope and exhausted all other therapies. We're just as interested as in first time patients.
Is SFA disease another name?
Dr. Lambert: The SFA is a specific artery, the superficial femoral artery, which is in your thigh. That's been the bugaboo of interventional radiology in cardiology in terms of this restenosis. Because there's a lot of disease that occurs there and it has been just very difficult to keep those vessels open long-term. There have been some other stents that share some of the characteristics of the flex-stent, not nearly as sophisticated and they've had some more promising results so you know I'm enthusiastic about this one.
It's safe to say that the flex-stent is geared towards people with peripheral arterial disease?
Dr. Lambert: Right, iliofemoral popliteal disease.
This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc. or any medical professional interviewed. Ivanhoe Broadcast News, Inc. assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors; always consult your physician on medical matters.