An arterial insufficiency ulcer is an open sore that develops on the body, typically on the lower extremities. These ulcers occur when the arteries, which carry oxygen-rich blood to the limbs, experience reduced or blocked blood flow. Without a steady supply of oxygen and nutrients, the affected skin and underlying tissues begin to break down, leading to the formation of a persistent wound. This condition is also known as an ischemic ulcer or ischemic wound.
Underlying Causes of Arterial Ulcers
Arterial ulcers are caused by insufficient arterial blood supply to affected tissues. This inadequate blood flow is most commonly a consequence of Peripheral Artery Disease (PAD). PAD develops when arteries that supply blood to the limbs become narrowed or blocked.
Atherosclerosis is the primary mechanism behind PAD, involving plaque accumulation—a mixture of fat, cholesterol, and other substances—on the inner walls of arteries. This process can be compared to a pipe gradually becoming clogged, restricting the flow of water. As plaque builds up, the arteries harden and narrow, diminishing the delivery of oxygen and nutrients to the skin and other tissues, particularly in the legs and feet.
Several factors contribute to atherosclerosis and PAD. Smoking is a major risk factor, as the chemicals in tobacco can damage the artery lining, accelerate plaque buildup, and constrict blood vessels. Diabetes, especially when not well-controlled, significantly increases the risk by damaging blood vessels and impairing circulation. High blood pressure can injure artery walls over time, while high cholesterol levels contribute directly to plaque formation. Advanced age also plays a role, as arteries naturally become less elastic and narrower over time.
Identifying an Arterial Ulcer
Arterial ulcers have specific characteristics. They often present with a “punched-out” appearance, typically round or symmetrical with well-defined, even borders. The base of the ulcer may appear pale, yellow, gray, or black, sometimes showing necrotic (dead) tissue, and usually has minimal to no drainage.
These ulcers commonly form on the lower legs and feet, frequently appearing on the toes, heels, or other bony prominences. Pain is a common symptom, often described as severe, and it tends to worsen when the leg is elevated, as this position further reduces blood flow. Dangling the affected leg can sometimes provide temporary relief as gravity assists blood flow.
Additional symptoms in the affected limb include a cold sensation to the touch, reflecting poor circulation. The skin around the ulcer may appear shiny, taut, and thin, with a noticeable loss of hair on the leg and foot. Pulses in the affected ankle or foot may be faint or absent due to restricted blood flow.
Medical Diagnosis and Evaluation
Diagnosing an arterial insufficiency ulcer begins with a physical examination. During this exam, the doctor will visually inspect the ulcer and the surrounding skin, assess skin temperature, and check for hair distribution. They will also check the pulses in the feet and ankles to gauge blood flow.
The Ankle-Brachial Index (ABI) is a primary non-invasive test to evaluate arterial circulation. This test compares the blood pressure measured in the ankle to the blood pressure measured in the arm. A normal ABI typically ranges from 1.00 to 1.40, while a reading of 0.90 or less can indicate PAD. An ABI below 0.50 suggests severe arterial disease and may be associated with significant tissue damage.
Further imaging tests can pinpoint blockages within the arteries. A Doppler ultrasound uses sound waves to create images of blood flow through the vessels, helping to identify narrowed or blocked arteries. In some cases, an arteriogram, also known as angiography, may be performed, which involves injecting a special dye into a blood vessel to make the arteries more visible on imaging scans, providing detailed information about the location and extent of blockages.
Approaches to Treatment
Treatment for arterial insufficiency ulcers focuses on two main goals: restoring adequate blood flow and providing local wound care. Restoring blood flow is essential for healing these ulcers. Medical procedures like angioplasty can be performed, where a balloon is inflated inside a narrowed artery to widen it, sometimes followed by the placement of a stent, a small mesh tube, to keep the artery open. For more extensive blockages, bypass surgery may be considered, which involves creating a new pathway for blood flow using a healthy blood vessel from another part of the body to reroute blood around the blocked artery.
Medications can also play a role in managing underlying conditions and improving blood flow. These may include drugs to manage blood pressure, cholesterol levels, or blood sugar, as well as antiplatelet medications to help prevent blood clots. These systemic treatments support the overall cardiovascular health, which directly impacts the limb’s perfusion.
Local wound care involves several steps to promote healing and prevent complications. Debridement, the removal of dead or infected tissue from the ulcer, is a routine practice to create a healthier wound bed for new tissue growth. This prepares the wound for appropriate dressings, which help maintain a moist environment conducive to healing while protecting against infection. Infection management, often involving antibiotics, is also a consideration if signs of bacterial growth are present in the wound.
Managing the underlying risk factors is a fundamental part of treatment and helps prevent recurrence. This includes lifestyle changes such as smoking cessation, which improves circulation and artery health. Diligent control of blood sugar levels for individuals with diabetes, and maintaining healthy blood pressure and cholesterol levels, are also important to slow the progression of atherosclerosis and support long-term wound healing.