Vascular bypass grafting can be performed to circumvent a diseased area of the arterial vasculature. The great saphenous vein is used as a conduit if available, although artificial (Gore-Tex or PTFE) material is often used for long grafts when adequate venous conduit is unavailable. When gangrene has set in, amputation may be required to prevent infected tissues from causing sepsis, a life-threatening illness. Thrombolysis and thrombectomy are used in cases of arterial thrombosis or embolism. Guidelines
A guideline from the American College of Cardiology and American Heart Association for the diagnosis and treatment of lower extremity, renal, mesenteric, and abdominal aortic PAD was compiled in 2013, combining the 2005 and 2011 guidelines. For chronic limb threatening ischemia the ACCF/AHA guidelines recommend balloon angioplasty only for people with a life expectancy of 2 years or less or those who do not have an autogenous vein available. For those with a life expectancy greater than 2 years, or who have an autogenous vein, bypass surgery is recommended. Prognosis
Individuals with PAD have an "exceptionally elevated risk for cardiovascular events and the majority will eventually die of a cardiac or cerebrovascular etiology"; prognosis is correlated with the severity of the PAD as measured by an ABI. Large-vessel PAD increases mortality from cardiovascular disease significantly.
High risk populations
Peripheral arterial disease is more common in these populations:
All people who have leg symptoms with exertion (suggestive of claudication) or ischemic rest pain
All people aged 65 years and over regardless of risk factor status
All people between 50 and 69 and who have a cardiovascular risk factor (particularly diabetes or smoking)
Age less than 50 years, with diabetes and one other atherosclerosis risk factor (smoking, dyslipidemia, hypertension, or hyperhomocysteinemia)
Individuals with an abnormal lower extremity pulse examination
Those with known atherosclerotic coronary, carotid, or renal artery disease
All people with a Framingham risk score of 10%–20%
All people who have previously experienced chest pain

Mechanism
As previously mentioned, the most common cause of peripheral artery disease, especially in patients over 40 years old, is atherosclerosis. Atherosclerosis is a narrowing of the arteries caused by lipid or fat build up and calcium deposition in the wall of the affected arteries. The most commonly affected site occurs at arterial branch points, because there is an increase in turbulence and stress on the artery at these areas where the artery branches to supply distant structures. Disease of distant structures, including feet and toes, are usually caused by diabetes and seen in the elderly population.Additional mechanisms of peripheral artery disease including arterial spasm, thrombosis, and fibromuscular dysplasia. The mechanism of arterial spasm is still being studied, but it can occur secondary to trauma. The symptoms of claudication ensue when the artery spasms, or clamps down on itself, creating an obstruction. Similar to atherosclerosis, this leads to decreased blood flow to the tissue downstream of the obstruction.