However, due to the presence of intravenous adhesions and venous anatomical stenosis and occlusion, acute thrombosis in the iliofemoral vein caused by IVCS is often less effective and can affect the arterial blood supply in cases of severe swelling, resulting in femoral cyanosis and even amputation. For patients who fail thrombolysis and miss the acute phase, conservative treatment is often used to wait for the establishment of thrombotic collateral circulation, but the slow establishment of collateral circulation and the failure of collateral circulation to meet the needs of venous return can lead to post-thrombotic syndrome of varying degrees, which seriously affects the quality of life of patients. Since IVCS is the main cause of secondary thrombosis, how to treat iliac vein compression also becomes the key to complete treatment of thrombosis. 1965 Cockett and Thomas gave a systematic description of IVCS, and also introduced the main surgical treatment methods, such as iliac vein dissection and angioplasty, right common iliac artery transposition, and venous bypass diversion, etc. Later, there were iliac vein band-ringing, and Double femoral vein diversion (Palma procedure) and other procedures were used for the treatment of this disease. However, most of these procedures are more invasive, more difficult to perform, and have poor long-term results, so there has been controversy in clinical treatment. With the improvement of endoluminal technology and the popularization of its application, endoluminal treatment of IVCS has gradually become the preferred method. Treatment methods include catheter-contact thrombolysis, ultrasound ablation, PTA, and stent placement. Endoluminal techniques have several advantages: 1. Intraoperative direct angiography allows direct evaluation of the degree of venous obstruction and collateral circulation; 2. Small-dose contact thrombolysis via catheter and iliac-femoral vein thrombectomy via jugular vein can remove thrombus with maximum preservation of valve function; 3. Adhesive structures in the vein can be released via PTA and/or Stent while removing thrombus. Ultrasonic ablation is an emerging ultrasonic thrombolytic technique, which is a treatment emerging abroad in the mid to late 1990s. Under the guidance of interventional technology, an ultrasonic probe is placed at the distal end of the thrombus after percutaneous puncture, and by releasing low-frequency, high-energy ultrasonic energy, it selectively acts on the thrombus, and through the mechanical vibration effect of ultrasound and cavitation effect, it eventually breaks up into fragments less than 7um in diameter, thus achieving It avoids the trauma and pain of traditional surgery and does not cause any damage to the blood vessel wall, and has the advantages of small trauma, rapid efficacy, safety and reliability, and repeatability, which provides an alternative method for clinical treatment of IVCS with thrombosis. Treatment of IVCS includes removal of secondary thrombosis, release of iliac vein stenosis, restoration of blood flow and preservation of venous valve function, and reduction of post-thrombotic syndrome. All requirements cannot be fully met by conventional methods, and the application of endoluminal techniques promises to successfully address this problem. Stenting after catheter-contact thrombolysis has become the treatment of choice for IVCS because of its safe and minimally invasive features, high technical success rate and vascular patency rate.