Atherosclerotic occlusive disease is a systemic disease that can occur in large and medium arteries throughout the body, with the distal abdominal aorta and the iliac, femoral and N arteries being the most common. The disease is mostly seen in men, and the age of onset is mostly above 45 years. Hyperlipidemia, hypertension, diabetes mellitus, and smoking are the risk factors. The earliest symptoms of the disease are coldness, numbness, and intermittent claudication in the affected limbs. If occlusion occurs in the lower abdominal aorta or iliac artery, there is soreness, weakness and pain throughout the buttocks and lower extremities after walking, and if the symptoms occur in the lower legs, it suggests a possible femoral artery occlusion. As the disease progresses, the ischemia of the affected limb worsens, and persistent resting pain may occur in the toes, foot or lower leg in a quiet state, more intense at night, and the patient often sits with his feet in his arms and stays awake all night. The affected toes, feet or calves have pale complexion, decreased temperature, decreased sensation, thinning skin, muscle atrophy, thickened and deformed toenails, and sparse bone. Severe ischemia produces ulcers and gangrene in the toes, feet, or lower legs. Patients with combined diabetes are especially susceptible to developing wet gangrene and secondary infections, which can be accompanied by systemic toxic symptoms. The more severe the arterial stenosis, the shorter the walking distance the patient can tolerate, until eventually he or she loses the ability to walk. At the later stage of the disease, the artery may even be occluded, when the limb is in a state of extreme ischemia even at rest, and the nerve endings produce severe pain, called “resting pain”, especially at night, so such patients often cannot sleep all night because of severe pain, causing great pain. At the same time, the skin, muscle tissue ischemia gradually loss of vitality, resulting in the affected foot, especially the toe ulcers or black gangrene, recurrent infection of the necrotic area often can not be controlled by ordinary drugs, resulting in the so-called “old rotten feet”. General examination: including blood lipids, electrocardiogram, blood glucose, etc. Among them, increased blood lipids or decreased high-density lipoprotein often indicate the possibility of atherosclerotic lesions, but normal blood lipids and high-density lipoprotein cannot exclude their existence, so the determination of total cholesterol, triglycerides, beta lipoprotein and high-density lipoprotein is only a reference value for diagnosis. Non-invasive vascular examination: segmental manometry and ankle/brachial index of the lower extremity can be used to understand the location and degree of lower extremity ischemia, which has become one of the routine examinations for patients with lower extremity arterial occlusion. CT angiography: Under the guidance of CT arteriography it can understand the site and extent of arterial blockage, output tract and collateral vessels before surgery, which is crucial to develop a suitable surgical plan. Treatment Non-surgical treatment: Weight reduction, strict prohibition of smoking and proper activity in obese people. Lipid-lowering treatment, blood pressure control, and blood glucose control for those with diabetes. Surgical treatment : (1) Percutaneous transluminal angioplasty is the expansion and recanalization of atherosclerosis or other causes of vascular stenosis or occlusive lesions through catheters and other devices. This treatment was applied in the 1960s and was mainly performed with balloon catheters until the 1980s, called balloon angioplasty. For single or multiple short-segment stenoses, a balloon catheter can be inserted percutaneously through a puncture to the stenotic segment of the artery, and the balloon is dilated and expanded with appropriate pressure to enlarge the diseased lumen and restore blood flow. If combined with the application of stent, it can improve the long-term patency rate; (2) Bypass diversion The use of autologous saphenous vein or artificial vessel to make a bypass diversion between the proximal and distal ends of the occluded segment. For aorto-iliac artery occlusion, aorto-iliac or femoral artery bypass can be used. In poor systemic conditions, a safer extra-anatomic bypass, such as axillary-femoral artery bypass, may be used.