Vascular and Interventional RadiologyE1013. May Thurner Syndrome: Presentation, Radiologic Diagnosis, and the Role of Endovascular Treatment
Buckley J1, Kauffman T1, Borsa J.1 1. No Institutional Affiliation
Address correspondence to J. Buckley (email@example.com)
Background Information: May Thurner Syndrome (MTS) is a condition in which anatomic compression of the left common iliac vein by the right iliac artery results in symptomatic venous outflow obstruction to the left lower extremity. This obstruction can result in chronic pain and swelling but is also an important cause of acute, often extensive, deep vein thrombosis (DVT). Left undiagnosed and untreated, this syndrome can result in significant morbidity and mortality, especially as it generally affects younger patients. The ability of a radiologist to recognize this condition is especially important as the mainstay of treatment is endovascular stenting rather than the traditional medical therapy often used for other causes of DVT.
Educational Goals/Teaching Points: Participants will understand the anatomy and physiology responsible for the development of May Thurner Syndrome; identify patients at risk for this syndrome based upon clinical history and secondary evidence of the disease; recognize and directly diagnose MTS on multiple modalities, including CT and angiography; understand the role of endovascular intervention for definitive treatment of the disease, including procedural steps and the role of intravascular ultrasound; and prepare for future discussions with other clinicians or patient by identifying indications for intervention as well as the expected risks and outcomes.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques: Compression of the left common iliac vein between the overlying right common iliac artery and the spine can easily be identified on CT or MRI. This isolated finding is relatively common and only results in functional venous outflow obstruction (May Thurner Syndrome) in a small percentage of patients. Aside from direct visualization of this compression, secondary findings of obstruction can be seen on ultrasound, CT, or MRI, such as DVT (acute or chronic), vessel wall hypertrophy, and collateral vessel formation. Angiography and intravascular ultrasound are the reference standard for diagnosis as they most sensitively demonstrate the degree, location, and length of vein obstructed. These findings are important for diagnosis as well as treatment planning in the case of stent placement.
Conclusion: Chronic venous outflow obstruction to the lower extremity as in the case of May Thurner Syndrome results in significant morbidity and even mortality. Although relatively rare, it is important for radiologists to be familiar with this entity so they may not only diagnose this syndrome directly, but also so they may raise clinical suspicion when associated secondary findings of the syndrome are seen in a patient with supportive clinical history. Interventional radiologists who are familiar with this syndrome may offer both diagnostic as well as therapeutic intervention in the form of angiography with endovascular stenting.