Atherosclerosis obliterans of lower extremity (PAD) is caused by the formation of atherosclerotic plaque of lower extremity, which leads to the stenosis and occlusion of lower extremity arteries, and then leads to chronic ischemia of limbs. With the improvement of the overall living standard of the society and the aging of the population, the incidence of arteriosclerosis obliterans of lower limbs is increasing year by year.

Arteriosclerosis obliterans of lower limbs is common in middle-aged and elderly people, often accompanied by smoking, diabetes, hypertension, hyperlipidemia and other risk factors. The existence and severity of symptoms of arteriosclerosis obliterans of lower limbs are influenced by many factors, such as the speed of disease progression, the number of collateral circulation, and the tolerance of individuals. Symptoms generally develop gradually from mild to severe, but when acute thrombosis occurs on the basis of arteriosclerosis obliterans, symptoms can suddenly increase.

There may be no obvious symptoms in the early stage, or only slight discomfort, such as chills and chills. After that, intermittent claudication gradually appeared, which is a characteristic symptom of arteriosclerosis obliterans of lower limbs. It shows that after walking for a certain distance, the affected limb is tired and sore and forced to rest for a while; Symptoms can be completely relieved after rest and reappear after walking again. The distance and rest time for each walk are generally fixed. In addition, there is a correlation between the ulcer site and the location of vascular lesions. When the lesion develops further, there will be resting pain, that is, patients will have limb pain at rest, which is easy to occur when they lie down and rest at night. In the end, ulcers and gangrene may appear in the limbs, mostly caused by minor injuries to the limbs.

For the severity of clinical manifestations, Fontine stage or Rutherford stage can be used to divide the clinical manifestations, so as to increase the objectivity of clinical evaluation and make the results of various clinical treatments more comparable. At present, Rutherford stages are commonly used, which are divided into 7 grades from light to heavy: 0 ~ 6 * * *.

1.Rutherford0 level

No clinical symptoms, normal treadmill test or reactive congestion test, no hemodynamic manifestations of arterial obstruction;

2.Rutherford 1

Mild intermittent claudication, full exercise treadmill test, ankle arterial pressure >: 50mmHg after exercise, but ankle arterial pressure is lower than about 20mmHg； at rest;

3. Rutherford II

Moderate intermittent claudication, between 1 ~ 3;

4. Rutherford III

Severe intermittent claudication, unable to complete the treadmill test, ankle arterial pressure after exercise

5. Rutherford level 4

Ischemic resting pain, resting ankle arterial pressure

6. Rutherford level 5

Small tissue defect, unhealed ulcer, focal gangrene of plantar diffuse ischemic lesion, ankle arterial pressure at rest.

7. Rutherford level 6

Large area of tissue defect, beyond the metatarsal plane, foot function can not be preserved, other standards are the same as Rutherford5 grade 5. (The standard treadmill test is conducted on a slope of 15 degrees at a speed of 2 miles per hour for 5 minutes).