Critical limb ischemia (CLI) is a severe complication of peripheral artery disease (PAD). PAD occurs when plaque builds up in blood vessels that deliver blood from the heart to other areas. CLI involves severe restriction of these vessels.
PAD is an often symptomless condition in which atherosclerosis (the build-up of plaque on the artery walls) reduces blood flow to the limbs through the peripheral arteries. Most often, this involves the legs. The most common symptom of PAD is leg pain while walking. The condition is treatable with lifestyle changes and medication.
However, severely blocked peripheral arteries can lead to CLI, which causes severe pain, ulcers, and possible gangrene. People with CLI may even require a limb amputation, so urgent treatment is necessary.
Read on to learn more about the symptoms and causes of CLI. This article also looks at how doctors diagnose the condition, treatment options, and more.
- Recurring leg pain: CLI causes severe burning sensations in the legs
and soles of the feet that continue to be extremely painful during rest, whereas earlier stage PAD leads to leg pain that hurts during movement but improves with rest. This leg pain may present even if it was absent in earlier stages of PAD. - Skin changes: The skin may become dry, smooth, or shiny.
- Ulcers: CLI leads to wounds and ulcers that do not get better.
- Muscle mass changes: The legs may lose muscle mass.
- Tissue death: Tissue death can cause gangrene to develop on the legs.
CLI can develop due to PAD, and atherosclerosis is the
Plaque is a waxy, fatty substance that can build up on the walls of crucial arteries throughout the body, including those that bring blood to the limbs. This narrows the arteries, making it harder for blood and oxygen to reach the legs or some vital organs, such as the brain or kidneys.
Some people with CLI develop it suddenly due to blood clots that break off and cause blockages in peripheral arteries.
Several genetic, medical, and lifestyle factors can increase a person’s risk of PAD and CLI. These include:
- being male and over the age of 60 years
- being female and having experienced menopause
- not getting enough regular physical activity or exercise
- having a family history of vascular disease
- smoking
- having any of the following conditions:
- high cholesterol
- high blood pressure
- diabetes
- overweight or obesity
To reach an accurate diagnosis, a doctor
They will also use a range of tests to measure blood pressure and oxygen levels in the limbs, including an ankle-brachial index. This measures blood pressure in the arms or legs.
Along with ongoing leg pain while at rest, a pressure value under 0.9 suggests reduced blood flow.
Similarly, a toe-brachial index measures blood pressure in the toe. A result under 0.50 indicates CLI.
Doctors may also use a TcPO2 test to measure skin oxygen levels, which indicate the ability of wounds to heal. If this test produces a reading of fewer than 30 millimoles of mercury and the individual has ulcers on the feet, the doctor is likely to diagnose CLI.
Ultrasound scans can show useful and detailed information about blood flow. Doctors may also use MRI or CT scans to provide clearer images of the blood vessels.
Learn more about how doctors screen for PAD.
The
Bypass surgery, also known as revascularization, involves using tissue from other veins, mainly the saphenous vein, or prosthetic grafts to build new arteries and reroute blood flow into the limb.
During an angioplasty, the surgeon inserts a thin, flexible tube into the narrowed vein before inflating a tiny balloon to hold the vein open.
A 2022 clinical trial compared open bypass surgery and balloon angioplasty for treating CLI. It found that those who received bypass surgery were 32% less likely to experience severe CLI complications.
However, some people did not have enough tissue remaining in the saphenous vein for the bypass, and the researchers found that this group had no significant differences in risk between the outlook of the procedures.
Amputation below the knee may be necessary in people who:
- develop gangrene or tissue loss due to CLI
- are not suitable candidates for either surgery
- undergo ineffective revascularization
Early diagnosis and treatment of PAD may help prevent it from progressing to CLI.
The best way to treat early peripheral disease is by making changes to daily life. These
- avoiding or quitting smoking, if applicable
- consuming a heart healthy diet, such as the DASH diet
- maintaining a moderate weight for a person’s body type
- managing stress as much as possible
- getting enough regular physical activity or exercise
Certain medications can also help, including:
- antiplatelet medications to help prevent blood clots and further artery narrowing
- statins to reduce cholesterol levels and other blood fats
- medications to reduce blood pressure, such as angiotensin II receptor blockers and ACE inhibitors
A person may require bypass surgery or angioplasty for PAD if other treatments do not work.
What are the early signs of critical limb ischemia?
Early signs of critical limb ischemia (CLI) are the typical symptoms of peripheral artery disease (PAD). Examples include leg pain and numbness, pins and needles in the foot, a foot that feels colder than the other, and a pale or discolored leg or foot.
What is the life expectancy of someone with critical limb ischemia?
According to a
A person’s doctor can provide more accurate information about their outlook based on their individual circumstances.
Critical limb ischemia (CLI) is a major complication of peripheral artery disease (PAD). When the peripheral arteries can no longer provide the legs or some internal organs with blood due to severe blockage, it can lead to consistent, severe pain, ulcers, and eventually gangrene.
Smoking, obesity, and aging can increase the risk of CLI. Treatment can involve bypass surgery or angioplasty. In some cases, a person may require an amputation below the knee.
Recognizing and treating PAD early with lifestyle modifications and medications may help prevent CLI.