It is an arteriovenous anastomosis, mainly used for uremia, deep vein thrombosis, preparation for vascular transposition, etc. Patients with uremia mostly suture the artery and adjacent vein in the forearm near the wrist area, and there are three main types of vascular anastomoses: end-to-end arteriovenous anastomosis, end-to-side anastomosis and lateral anastomosis. The arterial and venous end-lateral anastomosis is preferred. It is a free ligation of the radial artery of the distal cephalic vein of the limb and a proximal anastomosis to form an arteriovenous fistula. The arterial blood flows in the anastomosed vein, promoting arterialization of the vein for a purpose that allows repeated punctures. The vasculature of the arteriovenous endovascular fistula provides adequate blood for hemodialysis treatment and guarantees the adequacy of dialysis treatment. The arteriovenous endovascular fistula is the most commonly used vascular access for maintenance hemodialysis patients; it has the advantages of safety, adequate blood flow (200-300 ml/min), low chance of infection; it can be repeatedly punctured, and with good management of compression care, the use of endovascular fistula can be maintained for 4-5 years in general; . Does not affect the patient’s daily life and other advantages. For the presence of severe stenosis in the large veins or central veins in the proximal extremities, obvious thrombosis or due to adjacent lesions affecting venous return, positive ALLEN test in the forearm of patients, end-to-end anastomosis of forearm arteriovenous fistula is prohibited, and endovenous fistula is not suitable for arteriovenous fistula. Vascular conditions: The expected selected vein diameter is ≥2.5 mm and there is no significant stenosis, significant thrombosis or adjacent tissue lesion in the deep and/or central vein of the proximal limb. The artery diameter expected to be selected is ≥2.0 mm. When selecting the upper extremity site, the presence of a pacemaker on the same side should be avoided, the forearm end-to-end anastomosis should be selected, and the patient should have an intact palmar artery arch on the same extremity. Principles of surgical site: upper extremity first, then lower extremity; non-dominant side first, then dominant side; distal end first, then proximal end. The following vascular options are available: radial artery-cephalic vein fistula in the forearm, followed by ulnar artery-guia vein fistula in the wrist, vein transposition fistula in the forearm (mainly guia vein-radial artery), elbow fistula (cephalic vein, guia vein or median elbow vein-brachial artery or radial artery or ulnar artery in its branches), lower extremity fistula (saphenous vein-dorsalis pedis artery, saphenous vein-anterior or posterior tibial artery), nasopharyngeal fossa fistula, etc.