Arterial insufficiency refers to impairment of arterial blood flow leading to tissue ischemia and potentially necrosis. Such impairment can occur acutely (eg, trauma, thrombosis) or chronically (eg, atherosclerosis). Both acute and chronic arterial insufficiency can lead to the formation of lower-extremity ulcers. Arterial insufficiency can occur at any level, from large arteries to arterioles and capillaries. Tissue ischemia that leads to leg ulcers tends to occur more in the setting of large vessel or mixed disease.
The most common cause of arterial ulcers is atherosclerosis. Risk factors for the development of atherosclerosis include age, smoking, diabetes mellitus, hypertension, dyslipidemia, family history, obesity, and sedentary lifestyle. It should be noted that arterial insufficiency might act in concert with other pathological mechanisms leading to tissue necrosis and ulceration. Diabetic foot ulcers, for example, may result from the combination of neuropathy, trauma, and arterial insufficiency. Table 1 lists diseases associated with arterial insufficiency.
A number of conditions are associated with the formation of ulcers that can mimic arterial leg ulcers. A list of these conditions is given in Table 2.
Assessment and Documentation
The initial assessment of any ulcer begins with a thorough history and physical examination. Although most leg ulcers are caused by venous insufficiency, one must carefully assess for the presence of arterial insufficiency. Concomitant arterial disease can delay or prevent healing. Additionally, compression therapy, the cornerstone of treatment for venous insufficiency, can cause tissue necrosis and ulceration in patients with underlying arterial disease.
Ischemic ulcers tend to have a "punched-out" appearance, being small, round, and with smooth, well-demarcated borders. The wound base is typically pale and lacks granulation tissue. Wet or dry gangrene may be present. Arterial ulcers tend to occur over the distal part of the leg, especially the lateral malleoli, dorsum of the feet, and the toes. They can be shallow or deep and are frequently painful. In addition to these common features, the physical examination may reveal a decrease in peripheral pulses, lack of hair over the distal leg, and cyanosis, pallor, and/or atrophy of the surrounding skin. Lifting the leg greater than 30 degrees can induce pallor in the ischemic limb. When dropped to a dependent position, the limb may become very red.
Vasculitic ulcers tend to have some characteristics similar to ischemic ulcers, including their location, size, and shallow depth. There are several typical differences, however. Vasculitic ulcers frequently have irregular shapes and borders. Additionally, the base of the wound tends to be necrotic with significant vascularity. The surrounding skin is usually hyperemic rather than pale. Vasculitis may also feature other cutaneous manifestations, including palpable purpura, petechiae, and persistent urticaria.
Management of arterial ischemic ulcers classically includes conservative debridement, pain control, use of occlusive dressings, and improvement of circulation. Treatment is also directed at the pathogenic causes of arterial disease.
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Source: Hess CT. Clinical Guide to Skin and Wound Care. 6th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2008.