Peripheral Artery Disease (PAD)
By Grace Kim MSIII, Kameron Black MSIII, Rutit Pak MSIII, Andi Garcia MSIII and Bryan C. Kramer, MD - February 24, 2020
Peripheral Artery Disease (PAD)
By Grace Kim MSIII, Kameron Black MSIII, Rutit Pak MSIII, Andi Garcia MSIII and Bryan C. Kramer, MD
Peripheral artery disease (PAD) is the narrowing and restriction of blood flow to all parts of the body excluding the heart and brain. The mechanism of PAD is similar to coronary artery disease and cerebrovascular disease, with the majority of cases caused by atherosclerosis. Thus, all pa-tients with PAD symptoms should be assessed for risk of cardiovascular disease. (4) If PAD is suspected, initial evaluation consists of taking an ankle-brachial index (ABI), the ratio of lower and upper extremity blood pressures. Ultrasound and CTA can also be utilized to evaluate blood flow through vessels and narrowing of arteries.
PAD can remain asymptomatic for many years, but initial presentation may include various de-grees of intermittent claudication, or limb pain with exertion. It is completely relieved by rest and most commonly affects the calf, buttock, hip, and thigh. (1) Mild symptoms should be managed conservatively with lifestyle changes, risk factor modifications (e.g., tobacco cessation, control of blood pressure, glucose, and cholesterol), and exercise. (1, 3) Primary care providers should consider referral to a vascular specialist when the severity of symptoms become lifestyle debilitat-ing or progress to critical limb ischemia (CLI), which is defined as the presentation of rest pain, non-healing wounds, or gangrene. (1, 2)
Rest pain is usually described as a burning pain in the lower extremities that is worse with leg elevation. Patients usually complain of worsening pain at night that is only relieved by hanging the affected leg over the side of the bed or with ambulation. The positional pain relief can create a vicious cycle that can eventually cause the extremity to become edematous from a decrease in lymphatic return. This edema can cause further worsening of the tissue damage.
Non-healing wounds can be acute or chronic and are due to major disruptions in blood flow. This decreases the likelihood of a wound to heal properly in an appropriate amount of time. If a wound fails to heal in several weeks or is getting worse, the patient should be evaluated for arterial dis-ease. Surgical intervention may be considered when non-healing wounds fail treatments includ-ing debridement, antibiotics, proper wound dressing, negative pressure wound therapy, and hy-perbaric oxygen therapy. Healing or excision of the wound is imperative as it can progress to even more serious conditions such as infection or gangrene.
There are three types of gangrene: dry, wet, and gaseous. Dry gangrene causes skin to fall off, wet will cause blistering and swelling, and gaseous will cause bubbling due to bacterial infection. Gangrene can be a life-threatening condition if it is allowed to progress. The tissue will show changes in texture, color, smell and have pain as a consequence of lack of blood.
If conservative methods fail (Statin, hypertensive medications, glucose control, pain relief, exer-cise, careful foot care) and patient presents with severe signs of limb ischemia (described above), you may need to refer to a vascular surgeon for surgical options. Surgical options that may be considered are endovascular repair with angioplasty and stent, bypass of affected segment, or amputation if it cannot be fixed (very unusual). The only doctor who is an expert at all the treat-ment modalities is a vascular surgeon, and they can individualize the treatment for each patient to find the best solution.