Chronic Limb-Threatening Ischemia (Formerly Known as Critical Limb Ischemia)

Chronic limb-threatening ischemia (CLTI), formerly called critical limb ischemia, is severely blocked blood flow to your leg or foot. It’s an advanced stage of peripheral artery disease (PAD). You may have intense pain even when you’re resting and open wounds on your affected limb.

About 1 or 2 out of every 10 people with PAD develop CLTI. This serious condition increases your risk of heart complications, amputation and death.

Seek medical care right away if you think you have CLTI. Prompt treatment can save your limb and your life.

Symptoms of chronic limb-threatening ischemia

The most common symptom is foot or leg pain that occurs at rest. Often, this pain is worse when you elevate your leg or lie flat. It may wake you up at night. You might find that if you hang your leg off the edge of your bed or get up and walk around a small amount, it may relieve the pain.

Some people don’t feel any pain but have other symptoms, like:

• Skin sores that won’t heal
• Skin that looks purple, green or black due to tissue death

Healthcare providers call this condition “chronic” because symptoms are present for more than two weeks. But you shouldn’t wait to seek care. If you have any of these symptoms, seek medical attention immediately.

Chronic limb-threatening ischemia causes

Severe plaque buildup in your peripheral arteries (in any of your limbs, but typically your legs) causes CLTI. This process is called atherosclerosis. As your arteries narrow, less blood can reach certain tissues in your leg or foot. It’s harder for these tissues to remain healthy and strong, or to heal, without enough blood flow.

Plaque buildup is also responsible for the earlier stages of PAD, like leg cramps or achiness when you’re walking or exercising. But with CLTI, the plaque severely restricts blood flow. This means very little blood can get where it needs to go. That’s why CLTI symptoms are much more severe. Body tissues can even begin to die, or they won’t heal when damaged.

Risk factors

Anyone with PAD can develop chronic limb-threatening ischemia. You have an increased risk if you:

• Are over age 75
• Continue to smoke after your diagnosis
• Have diabetes
• Have chronic kidney disease
• Have atherosclerosis in another area of your body, too (coronary artery disease or cerebrovascular disease)
• Have depression

How to lower your risk

You can lower your risk of CLTI by working with a healthcare provider to manage peripheral artery disease in its earlier stages. This may involve:

• Taking medications
• Doing structured exercise therapy (supervised by a healthcare provider)
• Eating heart-healthy foods
• Quitting smoking
• Following your provider’s advice on foot care

Complications

Without treatment, CLTI can lead to limb loss (amputation). Having CLTI also raises your risk for a heart attack, stroke or dying. That’s because the same kind of plaque that builds up in your leg arteries can also build up in other arteries — including those that supply blood to your heart or brain.

How doctors diagnose this condition

Your healthcare provider will do a physical exam and talk with you about your symptoms. They’ll check your pulse at several different points along both arms and legs. If your provider thinks you may have critical limb ischemia, they’ll run some noninvasive diagnostic tests, like:

• Ankle-brachial index (ABI): This test compares blood pressure in your arms versus your ankles. It can show if blood has a hard time reaching your feet.
• Toe-brachial index: This test is like an ABI. But instead of measuring blood pressure at your ankle, it measures it at your toe.
• Pulse volume recordings: This is a part of the ABI test that measures volume changes caused by blood flow in your legs.

To help plan treatment, your provider may do imaging tests like a vascular ultrasound, CT angiogram, MRA or catheter angiogram.

How is chronic limb-threatening ischemia treated?

To treat CLTI, your healthcare provider will do one or more procedures or surgeries to restore blood flow and heal skin wounds. If there’s severe tissue damage that isn’t salvageable, you may need surgery to remove toes or even some or all of a limb. In addition to treatment for the affected limb, you’ll likely also need to take some medicines and change some habits to lower your risk of future complications.

Procedures and surgeries

Your provider may recommend one or more of the following treatments:

• Leg revascularization: This is a procedure or surgery to help blood flow better in your leg. It’s the gold standard for managing CLTI. But it’s not an option in some cases, like when there’s gangrene or irreversible tissue damage.
• Venous arterialization: This is an option if you can’t have your arteries opened up. A provider connects an artery to a vein to allow oxygen-rich blood to reach your foot that way.
• Wound care and infection control: Your provider will remove dead tissue (debridement) to prevent further damage and help nearby areas heal. They’ll suggest specific care to best heal the wound. Often, they’ll give you antibiotics if you have a bacterial skin infection.
• Amputation: Removing a portion of your toes or limb is a last resort. This can even save your life in certain situations. With new advances in prosthetics and physical therapy, most people can return to a fully functional life.

Medications and habit changes

Your provider may prescribe medicines to help keep the arteries open and lower your risk of a heart attack or stroke. Possible medicines include:

• Antiplatelet drugs and anticoagulants to lower your risk of blood clots
• High-dose statins to reduce your LDL (“bad”) cholesterol and limit the buildup of new atherosclerosis
• Antihypertensives to lower your blood pressure
• Medication or other treatments to manage diabetes

If you smoke, your provider will give you guidance on how to quit and suggest programs or medication to help.

Your provider will also talk with you about footwear and how to care for your feet. They may recommend using orthotics, like custom-made shoe inserts. These can help relieve pressure on certain parts of your foot. This promotes wound healing and prevents new wounds from forming.

When should I see my healthcare provider?

Contact a provider right away if you think you have CLTI. The sooner you get treatment, the better.

Treating CLTI takes time. You’ll have many appointments and follow-up visits — often with different types of providers, like vascular surgeons, podiatrists, dietitians and physical therapists. These visits are all crucial for your healing. Be sure to tell your providers if it’s hard for you to stick with your treatment plan or get to your appointments. They can offer resources to help.

What can I expect if I have this condition?

Treatment can help save your limb and your life. But each person is different, and many factors affect your outlook. These include:

• Whether it’s possible to restore blood flow to your limb
• How much tissue is damaged
• Your age
• Your other medical conditions

Your healthcare provider can help you understand what’s possible in your situation. It’s important to know that chronic limb-threatening ischemia is a serious condition that can lead to limb loss or death. For example, up to 1 in 3 people with CLTI need a major amputation (above the ankle) within one year of diagnosis.

But there are also many reasons to have hope. Treatments continue to improve. Surgeons are finding more and better ways to restore blood flow in people who have this condition. This means it’s often possible to heal tissue damage, feel better and keep your limb.

If you need an amputation, your care team will be there for you. They’ll connect you with resources to help you adjust both physically and emotionally.