Arterial Ulcer (Ischemic Ulcer)

How arterial ulcers develop

Arteries carry oxygen-rich blood to the legs. In peripheral artery disease (PAD), fatty plaque (atherosclerosis) narrows these arteries. When blood flow falls below what the skin needs, even a minor injury, such as a shoe rub, a cut while trimming nails, or pressure from bedding, cannot heal and breaks down into an ulcer. The most severe stage of PAD, with rest pain or tissue loss, is called critical limb ischemia.

Signs and symptoms

• Location: tips of toes, between toes, heel, ankle bones, top of the foot or lower shin, often over pressure points.
• Appearance: round with sharp edges, as if punched out; pale, gray, yellow or black base; little bleeding or fluid.
• Pain: often intense, worse at night or with legs raised, better with the legs hanging down.
• Surrounding skin: cool, shiny, thin and hairless; may turn pale when raised and dusky red when hanging (dependent rubor).
• Pulses: weak or absent in the foot.
• Other signs: thick, slow-growing toenails and leg pain when walking.

Arterial vs venous vs diabetic ulcers

Some people have mixed arterial and venous disease, which changes treatment, especially use of compression.

Causes and risk factors

• smoking, the strongest modifiable risk factor
• diabetes
• high blood pressure and high cholesterol
• older age
• kidney disease
• family history of heart disease or stroke
• less commonly: blood clots, vasculitis, Buerger's disease in young smokers, and Raynaud's phenomenon

Diagnosis

1. Examination of the ulcer, skin, and foot pulses.
2. Ankle-brachial index (ABI): blood pressure at the ankle divided by the arm. A value of 0.9 or below indicates PAD; below 0.4 suggests severe disease. In diabetes and kidney disease, stiff arteries can falsely raise the ABI, so toe pressures are also measured.
3. Doppler ultrasound: maps blood flow and blockages.
4. CT or MR angiography, or catheter angiography: to plan treatment.
5. Wound swab, blood tests and X-ray: if infection or bone involvement is suspected.

Treatment

Restore blood flow

The ulcer cannot heal without adequate blood supply. A vascular surgeon may recommend:

• Endovascular treatment: balloon angioplasty with or without a stent, through a small puncture in the groin.
• Bypass surgery: using a vein or synthetic graft to route blood around the blockage.

Wound care

• Keep the wound clean and protected, with dressings chosen by a wound care nurse.
• Dry black scabs (eschar) on a poorly perfused foot are often left intact until blood flow is restored, to avoid creating a larger wound.
• Treat infection promptly with antibiotics.
• Do not use compression bandages unless a clinician confirms arterial flow is adequate; compression can worsen arterial ulcers.
• Offload pressure with special footwear, heel protectors and pressure-relieving mattresses.

Medicines and risk factor control

• Stop smoking completely; it is the most important step.
• Antiplatelet medicine (aspirin or clopidogrel) and a statin, as prescribed.
• Control blood sugar, blood pressure and cholesterol.
• Pain relief, as ischemic pain can be severe.

Complications

Untreated arterial ulcers can become infected, spread to bone (osteomyelitis), progress to gangrene, and lead to amputation. People with arterial ulcers also have a high risk of heart attack and stroke from the same artery disease.

Prevention

Stop smoking, keep diabetes and blood pressure under control, walk regularly to build collateral circulation, check your feet daily, wear well-fitting shoes, and have a podiatrist trim nails if you have PAD or diabetes.

Frequently asked questions

What does an arterial ulcer look like?

An arterial ulcer is usually round with sharp, punched-out edges and a pale, gray, yellow or black base. It is often dry with little drainage. It typically appears on the toes, heel or top of the foot, and the surrounding skin is cool, shiny and hairless.

What is the difference between arterial and venous ulcers?

Arterial ulcers come from poor blood supply, appear on the toes or feet, look punched-out and are very painful, especially when the legs are raised. Venous ulcers come from poor vein return, appear near the inner ankle, are shallow and moist, and feel better when the legs are raised.

Why do arterial ulcers hurt more at night?

Lying flat removes the help of gravity, so even less blood reaches the feet. The tissue becomes starved of oxygen, causing pain. Many people find relief by hanging the leg over the side of the bed, which is a classic sign of severe artery disease.

Can arterial ulcers heal?

Yes, if blood flow to the area is improved, usually with angioplasty, stenting or bypass surgery, along with good wound care and stopping smoking. Without improved circulation, arterial ulcers rarely heal and can lead to gangrene and amputation.