Abstract:Iliac vein compression syndrome (IVCS) is a major cause of chronic venous disease. However, distinguishing patients who truly require endovascular intervention from those with incidental anatomical compression remains a major challenge in clinical practice. This review systematically summarizes the advances in imaging modalities for the diagnosis of IVCS, including color Doppler ultrasonography, computed tomography venography (CTV), venography, and intravascular ultrasound (IVUS), with particular emphasis on their clinical applications and inherent limitations. Based on recent clinical evidence, the indications supporting endovascular intervention are comprehensively reviewed, including the clinical benefits in patients with severe chronic venous disease, the application of IVUS-derived quantitative thresholds in treatment decision-making, the high prevalence of IVCS among patients with recurrent varicose veins, and the pathophysiological significance of iliac vein compression as an anatomical predisposing factor for deep vein thrombosis. In addition, the rationale for conservative management in patients with well-developed collateral venous circulation, the limited long-term efficacy of stenting in patients with severe stenosis, and the complementary value of functional hemodynamic parameters in guiding treatment decisions are also discussed. Current evidence suggests that treatment decisions based solely on the degree of anatomical stenosis have inherent limitations. A comprehensive assessment integrating clinical symptom severity, quantitative IVUS measurements, and functional hemodynamic evaluation may improve the precision of patient selection for endovascular intervention. Nevertheless, high-quality multicenter prospective studies are still warranted to further optimize the indications for endovascular treatment in patients with IVCS.