Typical case: The patient, male, 56 years old, with a history of diabetes mellitus for more than 20 years, combined with ischemic changes in the lower limbs (cold, pain, claudication, skin bruising, etc.) for 5 years, with progressive worsening of symptoms, especially in the right lower limb, was admitted to the hospital with “diabetes mellitus combined with ischemic changes in the lower limbs”. He was admitted to the hospital with “diabetes combined with lower limb ischemic changes”. In order to release the sympathetic nerve tension on the lower limb tissues and promote the expansion of lower limb blood vessels and the establishment of collateral circulation, so as to relieve the blood flow of the lower limb to the greatest extent possible, and finally achieve the purpose of relieving pain and promoting the healing of skin ulcer. After full communication with the patient and family, we decided to perform “CT-guided right lumbar sympathetic ganglion dissection”. The procedure was carried out by Nian Dingfang, director of the Department of Interventional Medicine. The procedure went smoothly, and the patient felt a rise in skin temperature and pain relief in the right lower limb during the procedure. Knowledge: The main diseases that cause arterial ischemia in the lower extremities are atherosclerotic occlusive disease, thrombo-occlusive vasculitis, and diabetes combined with neuropathy and peripheral vascular disease. In the early stage, the main manifestations are coldness, numbness and pins and needles in the affected limbs, the tips of the toes and toenails are obviously thickened and pale, followed by walking difficulties and pain, and the more intense the pain is in the dead of night. In the late stage, the main manifestation is the blackening and necrosis of the toes, outer ankles, heels and other terminal parts, and on the basis of necrosis, infection occurs and ulceration is formed, and even amputation is required to save life. In case the above two methods fail to work or the chance of surgery is lost, “CT-guided lumbar sympathetic ganglion disruption” is an ideal choice. By destroying the sympathetic ganglion in the corresponding area, the tension of the sympathetic nerve on the lower limb tissues is relieved, and the vasodilatation of the lower limb and the establishment of collateral circulation are promoted, thus relieving the blood flow of the lower limb to the greatest extent possible, and ultimately achieving pain relief and skin ulcer healing.