Thromboangitis obliterans (TAO), is a chronic occlusive disease characterized by segmental, aseptic inflammation of medium and small arteries and veins and thrombosis in the lumen of blood vessels.In 1908, Burger firstly researched the arteries and veins of 11 amputated limbs in healthy search and found that the pathological changes were mainly lesions of the Vascular thrombosis and mechanization, different from the traditional atherosclerosis, so this disease is also known as Buerger’s disease (Buerger’s disease), the domestic abbreviation of vasculitis. How to diagnose 1, medical history Smoking is one of the important causes of thromboembolic vasculitis, ask the patient in detail about the duration of smoking and the amount of smoking. Ask the patient about the duration of smoking and the amount of smoking. Ask the patient about the history of cold and freezing, and the history of thrombosed superficial veins. Ask the patient if he/she has been treated, and the status and effect of the treatment. Ask about the history of hypertension, diabetes mellitus, hyperlipidemia and arteriosclerosis. 2.Clinical manifestations The onset of the disease is mostly in male young adults (20-40 years old), usually less than 45 years old. There is a long course of the disease and clinical manifestations of limb ischemia, such as limb coldness, sensory abnormalities, Raynaud’s syndrome at the distal end of the upper and lower limbs, intermittent claudication, resting pain in the feet or hands, painful ulcers or gangrene at the extremities, superficial phlebitis, and the presence of proximal pulses but the disappearance of distal pulses. 3. Ancillary tests (color Doppler ultrasound, arteriography, CTA or MRA) show no evidence of arteriosclerosis, multiple, segmental occlusions or abrupt truncations of arteries distal to the knee or elbow, and the presence of some collateral circulation. 4. Rule out diseases such as arteriosclerotic occlusive disease of the limb, diabetic gangrene, aortitis major, arterial embolism of the limb, Raynaud’s disease, traumatic arterial occlusive disease, connective tissue disease vasculopathy, cold-injury vasculopathy, and allergic vasculitis. How to treat Thromboembolic vasculitis is a chronic occlusive disease of small and medium-sized arteries of undetermined etiology. The principle of treatment is to adopt comprehensive therapy according to the clinical manifestations and different stages of the disease, and the purpose of treatment is to prevent the progression of the lesion, improve and enhance the blood circulation of the affected limb, reduce or relieve pain, promote the healing of ulcers, try to save the limb, and improve the quality of life. (1) General treatment Smoking cessation is the first and foremost therapeutic measure, especially not indirect smoking; improve living conditions and pay attention to keeping warm: environmental stimuli such as cold, dampness and trauma should be minimized and avoided; appropriate exercise under the guidance of a doctor is beneficial to the relief of the disease. (2) Drug therapy Prostaglandin drugs have been proven to have a more definite effect on TAO, and can improve the clinical symptoms of patients to different degrees; other drugs such as hormones, antibiotics, vasodilators, antiplatelet, anticoagulant and expectorant drugs have not yet been widely recognized. For patients with coexisting acute thrombosis, thrombolytic drugs can be applied. Some patients also have some relief with the application of traditional Chinese medicine. 2, surgical treatment (1) indications for surgery: arterial reconstruction surgery is to prevent the progression of the lesion, improve and enhance the blood circulation of the affected limb, reduce or alleviate pain, promote the healing of ulcers, so as to save the limb of the effective method for the better limb arterial outflow and inflow tract of the patient can be carried out a variety of arterial bypass surgery. For patients who lack good limb arterial inflow and outflow tracts, lumbar sympathetic ganglionectomy, arteriovenous diversion surgery, autologous bone marrow or peripheral blood stem cell transplantation, and macroscopic omentum transplantation can be performed. For the above treatments are not effective, and the limb ulcers can not be healed and gangrene can not be controlled, then only amputation or toe amputation can be performed. (2) Timing of surgery: Surgery is mainly for patients with stage 2 or 3. stage 1 patients are not recommended to have surgery, and conservative treatment is the mainstay. (3) Selection of surgical program: lumbar sympathetic ganglionectomy: mainly for stage 1 and 2 patients, generally should be preoperative lumbar sympathetic nerve block test, if the skin temperature rises more than 1 to 2 ℃ after the block, the general effect of the postoperative period is better. If the skin temperature remains as it is, it means that the artery has been occluded, and after the vascular tension is lifted, it does not enhance the blood flow, so it is not suitable for sympathetic ganglionectomy. Autologous saphenous vein or artificial vascular bypass diversion: for arterial stage occlusion with a distal outflow tract. Arteriovenous Diversion: For patients with arterial occlusion distal to the artery without outflow tracts, inability to perform other revascularization procedures, unsatisfactory results of other treatments, severe ischemia of the limb, and patency of the deep veins of the lower leg without lesions. Bone marrow or peripheral blood stem cell transplantation: it is a treatment for severe peripheral arterial ischemic disease developed in recent years, especially for the pathogenesis is not clear, and need to rebuild the small blood vessels of the TAO has a better therapeutic effect. Amputation: for advanced patients, the ulcer cannot be healed and gangrene cannot be controlled, then only amputation or toe (finger) amputation can be performed.