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Common Causes of Critical Limb Ischemia

critical limb ischemia

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What Is Critical Limb Ischemia

Critical limb ischemia (CLI) is a serious condition that occurs when blood flow to the legs is severely reduced. This can lead to pain, numbness, and sores on the feet and legs. If left untreated, CLI can progress to gangrene, amputation, and even death. Studies show that about 40% of patients diagnosed with CLI require major lower extremity amputation.

CLI occurs in the later stages of peripheral artery disease (PAD), a condition caused by plaque buildup in the arteries of the legs. This plaque is made up of fat, cholesterol, cellular waste products, and fibrin. When plaque buildup narrows the arteries and restricts blood flow, the muscles, skin, and other tissues in the leg do not receive enough oxygen and other nutrients.

If PAD is not diagnosed and treated early enough, the progressive buildup of plaque can cause severe narrowing of the leg arteries, leading to CLI.

For personalized treatment recommendations to help prevent PAD from progressing to critical limb ischemia, request a consultation with one of our expert vascular doctors today.


Signs and Symptoms of Ischemic Leg

CLI is accompanied by symptoms that can be debilitating and impact your quality of life. The two most prominent signs indicating PAD has progressed to CLI are severe leg pain at rest (lasting two or more weeks) and non-healing sores and ulcers or gangrene in the legs.

Pain from CLI is debilitating and occurs even at rest, known as ischemic rest pain. If you have CLI, you may experience burning pain in the ball of your foot and toes. This pain tends to worsen at night while you’re lying in bed. CLI pain differs from the claudication seen in the early stages of PAD, which is triggered by physical activity but stops when at rest.

Due to a lack of blood supply, CLI can prevent any wounds on the foot from healing. These wounds may ulcerate and become infected. If left untreated, infected wounds can lead to tissue death (gangrene), which can result in amputation or death. Gangrene usually occurs in the toes as the extremely poor blood supply causes tissues to break down and die.

While these are the two most prominent signs of CLI, symptoms can vary depending on the severity of the condition. Other signs of CLI include:

  • Numbness or tingling in the legs or feet
  • Coldness in the feet or one leg feeling colder than the other
  • Dry or shiny skin on the legs and feet
  • Thickened toenails
  • Faint pulse in the legs or feet

If you notice these symptoms, they might indicate a severe form of PAD. Seeking a diagnosis from a vascular specialist can help you determine the best course of action for your health.

Complications of Severe Circulation Issues in the Legs, Feet, and Toes

CLI can lead to serious medical conditions like gangrene and acute limb ischemia while increasing the risk of strokes and heart attacks.

Gangrene occurs when bodily tissues die due to a serious infection or lack of blood flow. CLI severely restricts the blood supply to the leg tissues, depriving the muscles and skin of oxygen and other nutrients. Eventually, the condition may become so advanced that blood cannot reach the toe, foot, calf, or even the entire leg, and the affected cells begin to die. Wounds that won’t heal due to a lack of blood flow can become severely infected, contributing to gangrene. In most cases, the only treatment for gangrene is the amputation of the affected toes or leg.

Acute Limb Ischemia (ALI)
ALI is a severe complication of advanced PAD in which the plaque blockage ruptures, travels with the bloodstream, and lodges in a leg artery. This completely blocks the blood supply to the tissues supplied by that artery. Acute limb ischemia causes a weak pulse and extreme pain in the leg. This condition is a serious medical emergency, as both critical and acute limb ischemia can lead to amputation and death.

Heart Attack and Stroke
In addition to the risk of amputation, people with PAD are at a greater risk of life-threatening conditions like strokes and heart attacks. Almost one in three people diagnosed with critical limb ischemia undergo amputation, and one in four die due to stroke or heart disease within one year.
If you have constant leg pain, open sores, skin that’s cold to the touch, purple-black patches of skin, or any other worrying signs, see a doctor as soon as possible.

It’s important to distinguish between PAD leg pain and other sources of leg pain. If you notice a throbbing pain in one leg accompanied by redness, swelling, or unusually warm skin, seek emergency care. This type of leg pain can indicate deep vein thrombosis (DVT), a life-threatening condition.

The importance of consulting a vascular specialist and seeking medical care when you notice signs of PAD can’t be emphasized enough. The earlier your condition is treated, the better chance you have for a good prognosis.

If you notice any of these symptoms, don’t wait. Seek medical attention immediately.

Contact us to schedule an evaluation.

Risk Factors and Causes of Critical Limb Ischemia

Critical limb ischemia is a severe form of PAD. Because untreated atherosclerosis (the hardening of the arteries due to plaque buildup) is the primary cause of developing CLI, the risk factors of PAD and CLI include:

A PAD screening is recommended for anyone aged 65 or older, but if you live with a PAD risk factor like diabetes or smoking, you should be screened starting at age 50.

Critical Limb Ischemia Diagnosis, Treatment Options, and Prognosis

To diagnose CLI, a vascular doctor will perform a physical examination and may use one of the following tests to confirm the condition:

  • Ankle-brachial index: A comparison of the blood pressure measured at the ankle and blood pressure measured at the arm.
  • Ultrasound: An assessment of the direction and velocity of blood flow.
    CT angiography: An advanced X-ray that uses contrast dye and captures images of the blood vessels to determine blockage.

CLI treatment involves unblocking the narrowed arteries, restoring blood flow, and preventing the condition from worsening. Your vascular specialist may recommend one of the following treatment options:

  • Angioplasty and stent placement: During this procedure, an interventional radiologist inserts a tiny, balloon-tipped catheter into the affected artery, moving it to the affected area. The balloon is inflated to compress the plaque buildup against the walls and widen the lumen of the artery. This restores normal blood flow. Angioplasty is usually followed by placing a stent, a metallic mesh tube, at the affected area. The stent helps keep the artery open. Some stents are coated with a medication that prevents new blockages from forming.
  • Atherectomy: In this procedure, a small catheter with a tiny blade or laser is used to scrape away the plaque from the artery walls.

The prognosis for CLI depends on how early the patient seeks treatment. When the patient receives ongoing care to prevent the progression of the disease after the procedure, the prognosis is typically positive.  

Early treatment is key to a positive prognosis. Reach out to us to start your journey towards recovery.

Schedule a Consultation with USA Vascular Team

Critical limb ischemia is a serious condition, but treatment is available to prevent further damage. At USA Vascular Centers, our expert vascular specialists perform non-surgical, outpatient procedures that can alleviate your pain and help you regain your mobility. Schedule a consultation at one of our accessible centers across the country or give us a call at 888.773.2193.



Additional FAQs

How common is critical limb ischemia?

Current estimates suggest1 that 1.28% of US adults over age 40 live with critical limb ischemia. This translates to about 2 million people in the United States alone, and the number is expected to grow. Recent studies estimate2 that 8 million Americans over the age of 40 live with PAD. Without treatment, all cases of PAD will eventually progress to critical limb ischemia.

What are the stages of critical limb ischemia?

There are several ways to classify the stages of critical limb ischemia (itself one of the final stages of PAD). CLI can be broken down into three stages: rest pain, ischemic ulceration, and severe ischemic ulceration or gangrene.

Pain in the legs when at rest is the first sign of too much plaque in the peripheral arteries to allow normal circulation. For most people, the burning pain in the lower legs is constant. These patients may only find relief when they hang their feet over the edge of the bed.

The ischemic ulceration stage results in ulcers or slow-healing wounds on the legs and feet due to poor blood circulation. These ulcers can become infected; the only way to treat them is to address the underlying peripheral artery disease.

By the third stage, severe ischemic ulceration or gangrene, the ulcers have worsened to become gangrenous (dead tissue). At this stage, amputation may be necessary to save the person’s life.

Is limb ischemia life-threatening?

Yes. Limb ischemia can be life-threatening, especially if left untreated. Without adequate blood flow, the cells in the foot or leg can die, and the resulting ulcers and gangrene can become severely infected. If the infection reaches the bloodstream, it can cause sepsis, a very serious complication that can lead to death. In addition, critical limb ischemia is linked to a higher risk of heart attack and stroke. Receiving treatment for CLI and other vascular conditions can help reduce the risk of serious complications and increase your lifespan.

How painful is ischemia?

Ischemic leg pain is often described as a burning sensation in the feet and lower legs. This pain may be accompanied by numbness and tingling. The pain can be bad enough that it wakes you up from sleep. Moving around may help ease the pain somewhat by helping your body circulate blood; however, the pain is essentially constant. If you are experiencing ischemic leg pain, reach out to a vascular specialist as soon as you can. For more details on how to treat this chronic condition, schedule an appointment with one of our experienced vascular specialists.

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