Arterial ulcers are chronic, non-healing wounds caused by a significant lack of blood flow to the affected tissue, typically occurring in the lower extremities. This serious condition is a manifestation of impaired circulation, where arteries fail to deliver sufficient oxygen and nutrients. This failure results in tissue death and the creation of an open sore. This article explains the underlying mechanism of their formation, their characteristic appearance, the factors that increase risk, and the primary goals of treatment.
How Arterial Ulcers Develop
The primary physiological cause of arterial ulcers is Peripheral Artery Disease (PAD). PAD involves the narrowing and hardening of arteries, usually in the legs, due to a buildup of fatty materials and plaque called atherosclerosis. As these deposits accumulate on the artery walls, they progressively reduce the blood vessel’s interior diameter. This restriction limits the volume of blood that can pass through to the downstream tissues.
This reduction in blood flow, or arterial insufficiency, causes oxygen and nutrient deprivation in the lower limbs, particularly the feet and ankles. This tissue starvation is known as ischemia, which prevents cells from carrying out normal functions and initiating repair. When tissue lacks adequate perfusion, even a minor injury or abrasion cannot heal properly.
The starved cells eventually die, resulting in tissue necrosis and the breakdown of the skin, which manifests as an ulcer. In severe arterial disease, cell death can occur spontaneously without a preceding injury. Since the body cannot transport necessary components for wound repair due to poor blood supply, the ulcer persists as a chronic, non-healing wound.
Recognizing the Physical Signs
Arterial ulcers have a distinct physical appearance and specific symptoms that distinguish them from other wounds. They are most commonly found on distal points, such as the toes, heels, or outer ankle, often over bony prominences. The wound itself usually appears small, symmetrical, and round, with well-defined, even borders, often described as having a “punched-out” look.
The ulcer base is typically deep, potentially exposing underlying structures like tendons. It may have a pale, yellow, gray, or black color due to necrotic tissue. Due to poor circulation, the wound often shows minimal bleeding and lacks the healthy red tissue that signals new growth. The surrounding skin is frequently cool to the touch, appearing shiny, thin, and taut. There is often a noticeable loss of hair growth on the affected limb.
A distinguishing symptom is severe pain, which can be constant, even at rest, and worsens when the leg is elevated. Patients often find temporary relief by dangling the affected limb, as gravity slightly assists blood flow. A physical examination may also reveal diminished or absent pulses in the foot and ankle due to restricted arterial flow.
Major Risk Factors
Several systemic conditions and lifestyle choices increase susceptibility to the arterial narrowing that causes these ulcers. Cigarette smoking is a potent risk factor, as tobacco chemicals damage the inner lining of arteries and accelerate plaque buildup. This damage directly contributes to the progression of atherosclerosis.
Systemic Conditions
Diabetes mellitus is a major factor, as poorly controlled blood sugar levels damage small blood vessels and nerves, compounding reduced arterial flow. Hypertension, or high blood pressure, contributes by placing increased mechanical stress on artery walls, damaging the lining and promoting plaque deposition.
Cholesterol and Age
Hyperlipidemia, characterized by high levels of cholesterol and fats, provides the material for the atherosclerotic plaques that obstruct blood flow. Advanced age also increases risk because arteries naturally stiffen and narrow over time, making older adults more vulnerable to arterial insufficiency.
Goals of Treatment
Management focuses on two goals: restoring adequate blood circulation to the affected limb and providing meticulous local wound care. Addressing the underlying arterial insufficiency is the most important step, as local care alone cannot achieve healing without sufficient oxygenated blood. This often involves procedures aimed at improving flow, such as revascularization, which seeks to bypass or clear arterial blockages.
Surgical options for revascularization include creating a detour around the blocked artery or using minimally invasive techniques, such as balloon dilation, to open the narrowed vessel. Once circulation is improved, the second goal is managing the wound environment to promote healing and prevent complications. This involves professional debridement to remove non-viable, necrotic tissue from the ulcer base. Debridement is necessary to allow healthy tissue growth. Infection control is maintained through appropriate wound dressings and, if systemic infection is present, with antibiotics.