Health Matters: Hidden condition leads to limb loss
It’s that month of the year again, annually we take the time to discuss an issue of great importance. In some form or other, it affects most of us. September is the month to educate the public, to elaborate on the newest research, and honor those fallen victims. The issue of which I speak is PAD, peripheral arterial disease, a common condition affecting almost 20 million Americans.
Not that long ago, it was thought of as a rarity, not the common problem it is. Some estimates claim as much as 10 to 20% of the US population being afflicted with this vascular malady, which consists simply of the clogging of arteries. As many as 10 million Americans may suffer from occlusive (aka clogging) disease, becoming much more common as we age.
There are many types of artery disease, usually classified by location. Vessels around the heart can undergo this transformation, as can those running up to the brain. It turns out any artery can experience the build-up of plaque, reducing the space through which blood can travel. The long term consequences of reduced oxygenated, nutrient-rich blood are significant, potentially resulting in infection or limb loss. Affiliated afflictions include heart disease, stroke, and death. After all, an artery is just that, no matter where you’re looking.
Because of our aging population, the rising tide of obesity and diabetes, the incidence of peripheral arterial disease is increasing. Too many of us are employed in sedentary jobs, hunched over a desk, stuck in a cubicle. The amount of physical movement performed has decreased over the last half century, a trend only growing with computer games, the internet. Inactivity has a clear and obvious association with peripheral arterial disease.
There are numerous reasons PAD develops more in some than others. There’s always one’s genetic predisposition, naturally. Fitness has fallen as a whole, despite there being gyms and fitness centers in many communities. Most experts would point to our diet as being the most impactful explanation. Processed foods make up the bulk of many American’s nutritional intake, with significant implications for body weight, type 2 diabetes, vascular disease. As mentioned, age is an obvious factor, with PAD uncommon in those under 50.
PAD is a slow, insidious phenomenon, with plaque being deposited in the walls of our blood vessels gradually, over years. The classic symptom of the disease is termed intermittent claudication, which is pain that occurs in the feet or legs when the muscles are being used more, such as going for a walk. The increase in muscle work performed means a greater need for oxygen, which clogged arteries cannot provide, and pain results. With pain, most will rest and subsequently experience relief. With renewed ambulation, the same distance can be covered before the pain recurs. This is the reproducible “walk-pain-rest-relief” cycle.
Many physicians have been taught there is no danger if this claudication pain is not experienced, but studies reveal it occurs only about a third of the time. The result is that some with significant disease are not diagnosed in a timely fashion. PAD is often called a silent disease since many have no obvious symptoms. With time, many tissues can be affected. Skin becomes thin, dry, unhealthy. Hair follicles are very sensitive to blood flow so hair loss is usually seen, sometimes creating a sharp line of demarcation below which there is no hair. Toenails thicken, becoming discolored, brittle, and are often mistaken for having a fungal infection.
The astute physician will take note of these gradual changes and order a specialized study of arterial blood flow. This test is quite different than that used for venous problems, but too often the person being tested will not be educated on the difference. They leave the facility assuming they have good circulation since the (vein) test was normal. Again, the take home message: intermittent claudication is not diagnostic for arterial disease.
As this clogging process advances, PAD can transition into chronic limb-threatening ischemia, referred to as CLTI, a condition associated with increased mortality, risk of amputation, and impaired quality of life. This syndrome is characterized by PAD, accompanied by rest pain. This is pain which occurs when gravity is not helping the blood get down to the feet and lower legs, such as when one is sleeping. The afflicted typically will dangle their legs, alleviating the discomfort since gravity is again helping with blood flow. CLTI is often associated with gangrene and amputation. The former, as most are aware, is dead tissue: there is no healing of that.
All living tissues sicken when deprived of blood flow. With a sufficient reduction in supply, tissue death occurs. But there are other times increased blood flow is needed besides exercise. A basic blister or simple scrape requires tissue repair and that means having a sufficient source of blood. With long-standing PAD or CLTI, healing may be inadequate or non-existent. Those of us in wound care know well the caveat “We are held hostage by the blood flow.” It doesn’t matter what amazing technology or technique we use, without adequate arterial supply, healing of these wounds will not occur.
Numerous, precise methods exist for measuring arterial flow but are they ordered often enough? The data says “No,” the tell-tale indicators going unnoticed, the signs unheeded. Remember, only about 30% experience intermittent claudication, the pain that develops with exertion. Even then, many simply modify their activity levels to adapt. Interestingly, many of the physical changes associated with both PAD and CLTI are seen first in the feet. An astute podiatrist is often the first health care provider to identify the signs and symptoms of peripheral arterial disease and order the proper studies.
Treatments are many, depending on the severity of the disease. Our pharmacologic therapies (ie drugs) have met with only limited success. Minimally invasive surgical options are becoming increasingly commonplace. Complete replacement of a vessel, a by-pass procedure, is now relatively rare. Endovascular surgery, the term for this type of minimally invasive operation, rules the day. Unfortunately, these often re-occlude and the benefits subsequently lost.
Do we wait until frank and obvious signs of impending crisis are seen? Toes turning purple, dusky? The time to act is early, before the real repercussions of PAD evolve. With sufficient exercise, you can actually grow new blood vessels. Learn about diet and its close association with PAD. But early identification is the key, before it progresses to CLTI. If you have concerns, talk to your health care provider. And, yes, do some research.
Editor’s note: Dr. Conway McLean is a physician practicing foot and ankle medicine in the Upper Peninsula, with a move of his Marquette office to the downtown area. McLean has lectured internationally on wound care and surgery, being double board certified in surgery, and also in wound care. He has a sub-specialty in foot-ankle orthotics. Dr. McLean welcomes questions or comments at firstname.lastname@example.org.