Lower extremity deep vein thrombosis is a common vascular surgical disease in clinical practice. It is easy to cause limb disability and can endanger patients’ lives in serious cases. High blood viscosity, slow blood flow and damage to the vascular wall are the three main causes of this disease, which mostly occurs in people who are bedridden after various surgeries, chronic diseases and people with limited limb movement due to various reasons. Deep vein thrombosis refers to the abnormal clotting of blood in the deep venous system, which is usually found in the lower extremities, mostly in postpartum, post-pelvic surgery, trauma and long-term bedridden patients, mainly manifested as localized pain, which increases when walking. In mild cases, the local pain is only heavy, and the symptoms are aggravated when standing up. There are several features as follows: 1. swelling of the affected limb; 2. pain; 3. superficial varicose veins; 4. systemic reaction, including increased body temperature, increased pulse rate, increased white blood cell count, and increased D-dimer. Treatment: 1. anticoagulation and thrombolytic therapy: for acute and chronic thrombosis. 2. Inferior vena cava filter implantation: for extensive iliofemoral vein thrombosis in the acute phase with the possibility of pulmonary embolism. 3. inferior chamber filter implantation, fogarty catheter embolization: for extensive iliofemoral vein thrombosis with impaired arterial blood supply and the limb tends to gangrene (femoral cyanosis), surgical embolization is often required. The operation time of iliofemoral vein thrombosis removal is usually within 72 hours (at the latest not more than 10 days), especially the best result is within 48 hours. The earlier the surgery, the less the thrombus adheres to the vein wall, the lighter the inflammatory response, the lighter the destruction of the vein lining, the less the secondary thrombosis, the more complete the surgical removal of the thrombus, and the best postoperative outcome! Patients with lower extremity thrombosis: Placement of inferior vena cava filter: Removal of thrombus: Removal of thrombus: Removal of thrombus