Fighting for Your Legs: Peripheral Arterial Disease Is On The Rise
For the aging population, risk of Peripheral Arterial Disease is on the rise.
Peripheral Arterial Disease (PAD), a condition synonymous with the clogging of arteries in the body’s lower extremities, is often referred to as a “silent killer” that can bring with it potentially grave results that include gangrene, amputation, or death.
Data shows that PAD currently affects approximately eight million men and women over the age of 40 in the United States. What’s more, the risk of developing PAD increases dramatically as people grow older, with as many as one in 20 Americans over the age of 501 developing the disease.
Although PAD is prevalent among the senior population, current statistics shows public awareness about the disease is low.2 In fact, only 25 percent of those afflicted receive treatment3, in large part due to frequent misdiagnosis of commonly mistaken symptoms. In many instances, especially among the senior community, PAD is mistaken for arthritis or aging pains, allowing the disease to remain undiagnosed, untreated, and left to intensify.
PAD develops when arteries in the legs become clogged with plaque comprised of fatty deposits, calcium, and cholesterol and blood flow to the legs becomes limited or blocked. In severe cases, the arterial blockages can cause circulation problems that reduce blood flow to the brain and heart, which then elevate the risk for stroke and heart attack.
PAD is broken down into two stages that worsen as blood flow to the legs decreases: Claudication and Critical Limb Ischemia (CLI). Claudication, the first stage, begins with a feeling of fatigue or heaviness in the lower extremities or buttocks and progresses to significant discomfort during activity. Patients with buttock claudication will frequently stop walking until the pain goes away, a condition know as “window shopper’s disease.” The second stage, CLI, starts off with pain while resting or sitting and, if left untreated, may lead to gangrene. Within the CLI population alone, at least 200,000 amputations are performed each year4.
In addition to the correlation between PAD and the aging population, diabetics are also especially susceptible to PAD because they have difficulty properly processing the sugar they ingest. Also, smoking and heritage, such as African Americans, Hispanic Americans and Native Americans, are heightened risks for developing severe PAD that results in amputation.
Knowing the Difference
For senior citizens, it’s not out of the ordinary to have some leg pain after a long and vigorous walk. However, when pain and cramping exist after short walks or mild activity, it could be an indication that there are blockages within the peripheral arteries.
Early detection of PAD is essential to maintaining a high quality of life for those afflicted with PAD. Below is a list of warning signs and symptoms that should be monitored closely:
* Fatigue or cramping in the leg muscles (known as claudication) when walking
* Pain in the legs, buttocks and/or feet that disturbs sleep
* Wounds on toes, feet or legs that heal slowly, poorly, or not at all
* Color changes in the skin of the feet (paleness or blueness)
* A lower temperature in one leg when compared to the other leg
* Poor nail growth and decreased hair growth on toes and legs
Seeing Your Doctor
Two of the most common methods used to test patients for PAD are the ankle-brachial index (ABI) and the Doppler ultrasound test. The ABI is a noninvasive, painless, and reliable test that works by comparing blood pressure in the ankles and arms. An ABI test is useful in determining if someone has PAD, but cannot locate the blocked artery. The Doppler test, which is also noninvasive, manipulates sound waves to evaluate blood flow in lower extremities, often locating the blockage.
Treatment for mild PAD is largely behavioral, as the condition can be mitigated with a regimen of walking, a low cholesterol diet for diabetics, cessation of smoking and, in some cases, medication. For severe PAD, however, treatment may require an invasive bypass surgery or angioplasty.
Lower extremity bypass surgery involves harvesting a healthy vein from another region of the body for insertion into the damaged limb, an effort to reroute blood away from the blocked artery. Angioplasty is a minimally invasive procedure used to widen arteries with constricted or blocked blood flow. During the procedure, a catheter with a balloon on its tip is inserted into the narrowed artery and inflated. Once the artery widens, the balloon is deflated and the catheter is withdrawn, often restoring blood flow.
Another option in specific arteries (such as the iliac) is to have a stent (a tubular wire-mesh tube) inserted into the artery, where it is expanded to act as a “scaffold” to hold the artery open and allow blood flow to resume. The procedure is minimally invasive, as the stent is guided into the restricted artery with a catheter inserted through a small opening in the artery located in the groin.
Drug-eluting stents, which are coated with medicine that is slowly released into the artery, were created to prevent the recurent disease from growing through the stent and forming scar tissue, a process called restenosis. These devices have shown clinical effectiveness in treating coronary artery disease, and are currently being studied in the leg arteries.
In the United States and other parts of the world, clinical trials are currently underway to determine the effectiveness of using drug-eluting stents to treat PAD. The trial process is similar to the procedure used to treat coronary artery disease, and involves inserting a drug-eluting stent into the affected leg.
One particular investigational device involved in these recent trials is the Zilver PTX Drug-Eluting Stent (zilverptxtrial.com) from Cook Medical. The Zilver PTX stent is coated with paclitaxel, a drug approved for use as an anti-cancer agent and used successfully with coronary stents to reduce the recurrence of narrowing in the arteries following stenting. The amount of paclitaxel used is minimal compared to the amount used to treat cancer. It was created with the intention of staving off relapse in the nearly 40 percent of patients5 who now must endure repeat procedures when arteries renarrow. The Zilver PTX Trial is currently enrolling patients in clinical trial locations across the U.S. and Japan.
In the meantime, doctors across the country are working to increase general awareness and help identify the early warning signs of the disease. It is their hope that this heightened awareness, paired with the acceptance of innovative new treatment methods, will help eradicate PAD completely.
By Dr. Gary M. Ansel, Director of the Center for Critical Limb Care and Clinical Director of the Peripheral Vascular Intervention-Division of Cardiology at Riverside Methodist Hospital