Critical limb ischemia is a potentially serious condition that occurs when a leg or arm does not receive an adequate supply of new blood. Cholesterol buildup, blood clots in major arteries, and other circulatory problems may be responsible for symptoms. Critical limb ischemia is usually characterized by pain, weakness, and swelling in the affected body part that often worsen during sleep or prolonged periods of sitting or standing. If blood supply is severely restricted, skin and underlying tissue can begin to erode and form dark lesions. Treatment measures are targeted at correcting the underlying factors and may include medications, major lifestyle changes, and surgery.
In most cases, critical limb ischemia is a complication of peripheral artery disease (PAD). PAD refers to a narrowing or blockage in a vital artery in the leg caused by high levels of cholesterol and triglycerides in the blood. Cholesterol hardens and attaches to the walls of the artery over time, which limits the amount of blood that can reach the limb while significantly raising blood pressure. An unrelated blood clot, congenital blood vessel defect, or autoimmune disorder is responsible for critical limb ischemia in a small number of patients.
PAD and resulting critical limb ischemia tend to develop gradually. A person may first notice minor pain and swelling in his or her leg in the morning that resolves quickly. Over time, however, pain and weakness tend to worsen and cause problems during the day. Symptoms can become bad enough to disrupt sleep and make everyday activities such as walking and driving almost unbearable. Without treatment, decreased blood flow to the skin can cause tissue death and ulcers.
Most people who experience critical limb ischemia already know they are at risk of PAD from previous doctor visits. It is important to visit a doctor when arm or leg problems become chronic so that a PAD diagnosis can be confirmed and treated appropriately. A physician can perform a physical, ask about symptoms, and analyze blood samples to gauge the severity of the problem.
When limb ischemia is discovered early, it is often responsive to medications and lifestyle changes. Patients are typically instructed to maintain low-fat, low-salt diets, get regular exercise, and abstain from tobacco and alcohol. Blood pressure drugs and cholesterol-lowering medications are often prescribed to try to reverse the problem. Surgery is considered as a final option if symptoms fail to improve.
If surgery is necessary, a specialist may choose to insert a hard stent into the damaged artery or bypass the area altogether. An angioplasty procedure involves placing a balloon into the blood vessel and inflating it to spread the walls apart. A stent is placed in the artery to hold it open and prevent cholesterol from building up further. Bypass requires cutting off blood supply to the artery and putting either an artificial or donor blood vessel in its place. Most patients are able to recover from surgery if they follow their doctors' instructions about smart lifestyle decisions.