July 30, 2021 by John Fernandez
Critical Limb Ischemia – ‘A Threat to Life and Limb’
There’s a growing worldwide epidemic of critical limb ischemia (CLI) that threatens to disable approximately 2 million Americans, according to a 2019 study published in the journal Vascular Health and Risk Management.
Often caused by peripheral artery disease (PAD), CLI results from inadequate blood flow to the legs and feet caused by atherosclerosis, or plaque buildup, in the arteries that supply blood to these lower extremities. Critical limb ischemia can also be caused by diabetes, chronic kidney disease and hypertension, or high blood pressure. When tissues of the legs and feet are robbed of oxygen-rich blood, they can become painful, heal slowly and eventually die, setting up the need for amputation. Yet, beyond disabling victims, CLI can lead to death.
Barry Katzen, M.D., an interventional radiologist who treats patients with CLI and is the founder and chief medical executive of Miami Cardiac & Vascular Institute has taken on another role to raise awareness about this deadly condition. Dr. Katzen also serves as president of the CLI Global Society Board.
“Through research we, at Miami Cardiac & Vascular Institute, and others have been involved with, we’ve found that the five-year death rate of people diagnosed with CLI is higher than many of the deadliest cancers, including pancreatic, colorectal, liver and breast cancer,” Dr. Katzen said. A study he co-authored in 2018, published in the Journal of the American Heart Association, found that the mortality rate of people five years past diagnosis of CLI was 60 percent.
Dr. Katzen credits the high mortality rate to a lack of awareness by the public and many doctors about CLI, diagnosis and treatment options. By the time most people are diagnosed with the disease, aggressive intervention is needed.
“Generally, this disease affects people in their 60s and beyond, when disease processes like atherosclerosis, hypertension and diabetes begin to take their toll on our vascular health,” he said. “It’s important to recognize the signs of critical limb ischemia.”
Symptoms of Critical Limb Ischemia
Dr. Katzen warns anyone with peripheral artery disease, coronary artery disease, carotid artery disease, high blood pressure, chronic kidney disease and diabetes to be especially aware of any of the following signs that critical limb ischemia may have developed:
- Pain in the leg, ankle or foot while resting, especially at night.
- Non-healing wounds on the legs or feet with or without pain.
If you have these symptoms, Dr. Katzen recommends you speak to your primary care doctor or specialist about diagnostic testing to measure blood flow to your legs and feet.
Diagnosing Critical Limb Ischemia
He says the most common test to determine whether there may be a blockage in an artery to the legs is a non-invasive test called an ankle-brachial index. The test compares the blood pressure in the legs to the blood pressure in the arms. If the blood pressure is weaker in the legs, the ankle-brachial index is low and blood flowing to the ankles may be encountering resistance along its path to the feet. If the ankle-brachial index reveals this phenomenon, a test to measure the amount of or visualize the path of the blood flow through the blood vessels, such as an ultrasound or an angiogram using a computerized tomography (CT) scan or magnetic resonance imaging (MRI) technology, along with more extensive functional analysis of the blood flow, can confirm CLI.
While for some individuals with advanced CLI that has led to gangrene or tissue death, amputation may be necessary, Dr. Katzen wants people with CLI to know that, in many cases, there are treatment options that don’t involve such drastic and disabling measures.
“We now have the technology and the expertise of more than 15 years of studying this disease to know that endovascular or surgical revascularization is an option for some people,” he said. “It also has been proven to extend life expectancy and improve morbidity by reducing the need for amputation.”
In fact, the study that Dr. Katzen co-authored found that compared with revascularization, amputation doubles the risk of death over the next year. Conversely, the study found, in patients with gangrene, endovascular or surgical revascularization doubles patient survival compared to amputation.
Dr. Katzen points to the multidisciplinary team of interventional radiologists and vascular surgeons at Miami Cardiac & Vascular Institute as a key solution to the problem of mortality related to CLI.
“With interventional radiologists and vascular surgeons working together, we review cases and determine what treatment is best for the patient and his or her lifestyle,” he said. “Sometimes we may be able to restore blood flow through a minimally invasive endovascular procedure where a catheter is used to deploy a balloon to push the plaque against the vessel wall and to place a stent in the blood vessel to prop it open. We can similarly scrape the plaque from inside the vessel using a catheter approach, known as an atherectomy. Or a vascular surgeon may need to bypass a blockage with a vessel taken from elsewhere in the leg or a synthetic graft.” Institute doctors, including Dr. Katzen, are also taking part in the DETOUR2 trial, testing a bypass procedure done using a catheter.
Dr. Katzen and other physicians with Miami Cardiac & Vascular Institute understand that amputation is a life-altering event for patients and their families and can lead to complications resulting in premature death. Their multidisciplinary approach has made the Institute the go-to place for amputation prevention and for the care of advanced, complex CLI, Dr. Katzen says.
“We strive to avoid amputation when we can,” he said. “But it’s not just about saving a limb, it really is about saving a life.”