From the Guidelines
The narrowing of the proximal common iliac vein due to compression by the distal aorta or proximal common iliac artery should be managed based on symptom severity, with asymptomatic patients undergoing observation and regular follow-up, while symptomatic patients may require anticoagulation, endovascular stenting, or surgical decompression. The condition, known as May-Thurner syndrome (MTS) or iliac vein compression syndrome, occurs due to the compression of the left common iliac vein by the right common iliac artery, leading to restricted blood flow and potential thrombosis 1.
Diagnosis and Treatment
The diagnosis of nonthrombotic iliac vein lesions (NIVL) involves the use of invasive diagnostic techniques, including venography and intravascular ultrasound (IVUS), with dynamic IVUS evaluation recommended to assess the severity of the lesion 1. The use of thresholds, such as >50% area reduction or >61% diameter stenosis on IVUS, can help guide treatment decisions, with intervention recommended for lesions exceeding these thresholds 1.
Management Approach
For asymptomatic patients, observation with regular follow-up is appropriate, as the presence of compression alone is not a sufficient indication for antithrombotic prophylaxis 1. For symptomatic patients, anticoagulation with direct oral anticoagulants (DOACs) may be recommended initially, with endovascular stenting considered if symptoms persist or if there is evidence of deep vein thrombosis 1. Post-stenting, patients may require antiplatelet therapy, although the use of anticoagulation and antiplatelet therapy is not universally recommended and should be tailored to the individual patient's risk factors 1.
Key Considerations
The technical success rate of endovascular stenting exceeds 90%, and long-term patency rates range from 96% to 99% 1. However, stent-related adverse events, such as migration and stenosis/thrombosis, can occur, and regular imaging surveillance is recommended to monitor for these complications 1. The management of NIVL should prioritize a patient-centered approach, taking into account individual risk factors and symptom severity to optimize outcomes and minimize the risk of complications 1.
From the Research
Narrowing of Proximal Common Iliac Vein
- The narrowing of the proximal common iliac vein secondary to extrinsic compression via the distal aorta/proximal common iliac artery is a condition known as iliac vein compression syndrome (IVCS) or May-Thurner syndrome 2, 3, 4.
- This condition occurs when the left common iliac vein is compressed by the overlying right common iliac artery, resulting in a reduction of the vein's lumen and subsequent inhibition of venous outflow 2, 5.
- The compression can lead to acute iliofemoral deep vein thrombosis (DVT) or chronic venous insufficiency, with symptoms such as swelling, pain, and heaviness in the affected leg 2, 3, 6.
Diagnosis and Treatment
- Diagnosis of IVCS can be made using various imaging modalities, including duplex ultrasonography, magnetic resonance venography, and computed tomography (CT) scans 3, 5.
- Treatment options for IVCS include catheter-directed thrombolysis, thrombectomy, venoplasty, and stent placement, with the goal of restoring patency to the venous system and relieving symptoms 3, 4, 6.
- Intravascular ultrasound (IVUS) can aid in the diagnosis and operative planning of IVCS, particularly in sizing and deploying venous stents 4.
- Studies have shown that endovascular treatment of IVCS can achieve good patency and vein function, with primary patency rates ranging from 85.2% to 96.7% at 1-5 years of follow-up 6.
Clinical Implications
- IVCS is a significant cause of iliofemoral DVT, with approximately 2-5% of patients with chronic deep venous insufficiency of the left leg having IVCS 2.
- Recognition and treatment of IVCS can improve patients' quality of life, reducing symptoms and preventing long-term complications such as postthrombotic syndrome 2, 6.
- Further research is needed to establish the long-term benefits of treatment for IVCS and to optimize diagnostic and therapeutic strategies for this condition 6.