This system was created on the basis of ischemia and angiographic disease patterns not being the sole determinants of amputation risk. The WIfI classification system is broken up into two parts: wounds and ischemia. Wounds are graded 0 through 3 on the presence of ulceration and/or gangrene and ischemia. Grade 0: no ulcer, no gangrene
Grade 1: small, shallow ulcer; no gangrene
Grade 2: deep ulcer with exposed tendon or bone, gangrene limited to toes
Grade 3: extensive, full-thickness ulcer; gangrene extending to forefoot or midfootIschemia is graded 0 through 3 based on ABI, ankle systolic pressure, and toe pressure. Grade 0: ABI 0.8 or higher, ankle
Grade 1: arterial brachial index 0.6 to 0.79, ankle pressure 70 to 100 mm Hg, toe pressure 40 to 59 mm Hg
Grade 2: ABI 0.4–0.59, ankle pressure 50 to 70 mm Hg, toe pressure 30 to 39 mm HgThe TASC (and TASC II) classification suggested PAD treatment is based on the severity of disease seen on angiogram. Screening
It is not clear if screening for disease in the general population is useful as it has not been properly studied. This includes screening with the ankle-brachial index.Testing for coronary artery disease or carotid artery disease is of unclear benefit. While PAD is a risk factor for abdominal aortic aneurysms (AAA), there is no data on screening individuals with asymptomatic PAD for abdominal aortic aneurysms. In people with symptomatic PAD screening by ultrasound for AAA is not unreasonable.
A decrease in ABI of 15%–20% would be diagnostic of PAD.If ABIs are abnormal, the next step is generally a lower limb Doppler ultrasound to look at the site of obstruction and extent of atherosclerosis. Other imaging can be performed by angiography, where a catheter is inserted into the common femoral artery and selectively guided to the artery in question. While injecting a radio-dense contrast agent, an X-ray is taken. Any blood flow-limiting blockage found in the X-ray can be identified and treated by procedures including atherectomy, angioplasty, or stenting. Contrast angiography is the most readily available and widely used imaging technique. Modern computerized tomography (CT) scanners provide direct imaging of the arterial system as an alternative to angiography.Magnetic resonance angiography (MRA) is a noninvasive diagnostic procedure that uses a combination of a large magnet, radio frequencies, and a computer to produce detailed images of blood vessels inside the body. The advantages of MRA include its safety and ability to provide high-resolution, three-dimensional imaging of the entire abdomen, pelvis and lower extremities in one sitting. Classification
The two most commonly used methods to classify peripheral artery disease are the Fontaine and the Rutherford systems of classification.