May-Thurner Syndrome: An Under-Recognized Etiology of Deep Vein Thrombosis (DVT).

Background and Aims: May-Thurner Syndrome (MTS) is a rare vascular condition characterized by the compression of the left iliac vein by the overlying right iliac artery. This anatomical anomaly predisposes patients, especially young to middle-aged women, to deep vein thrombosis (DVT), which when it persists, leads to complications such as pulmonary embolism and chronic venous insufficiency. Despite its clinical significance, there is a lack of standardized guidelines for diagnosis and management. This review aims to summarize current knowledge on the epidemiology, pathophysiology, diagnostic approaches, and therapeutic strategies for MTS while highlighting challenges in establishing a consistent clinical framework. Methods: A comprehensive literature search was conducted using PubMed and Google Scholar, focusing on English-language studies involving human subjects. Sources included case reports, case series, clinical trials, systematic reviews, and expert consensus guidelines. Additional literature on iliac vein pathophysiology and venous thromboembolism management was reviewed to provide broader clinical context. Reference lists of key publications were manually examined for additional relevant studies. The final literature search was completed on April 5, 2025. Results: Common diagnostic methods for MTS include duplex ultrasound, CT venography, and MR venography, with intravascular ultrasound showing the highest sensitivity (> 98%). Endovascular stenting, often combined with catheter-directed thrombolysis, provides significant symptom relief and reduces post-thrombotic syndrome. In contrast, angioplasty alone was linked to higher recurrence rates. Long-term patency rates following stenting ranged from 79% to 100%. However, the absence of standardized diagnostic and treatment protocols contributes to variability in clinical outcomes. Conclusion: MTS remains an underrecognized cause of DVT, especially among young women. Although advances in diagnostic imaging and minimally invasive interventions have improved management, the lack of evidence-based guidelines continues to interfere with optimal care. Early diagnosis and individualized treatment plans are crucial, and further research is needed to establish evidence-based protocols for consistent management of MTS.