May-Thurner syndrome describes compression of the left common iliac vein where the right common iliac artery crosses over it against the lumbar spine. The chronic compression and repetitive pulsatile trauma can produce venous outflow obstruction, left-leg swelling, and a predisposition to iliofemoral deep vein thrombosis.
Clinical presentation
Patients are often young to middle-aged women presenting with unilateral left-leg swelling, heaviness, or pain, and in some cases acute iliofemoral DVT. Chronic cases may show signs of venous hypertension, including varicosities or skin changes. A high index of suspicion is important because the anatomic lesion is easily overlooked.
Diagnostic criteria
- Cross-sectional imaging (CT or MR venography) demonstrates the arterial crossover and iliac vein narrowing.
- Duplex ultrasound supports assessment of flow and thrombosis, though the iliac segment can be difficult to visualize.
- Intravascular ultrasound (IVUS) is particularly valuable, quantifying the degree of compression and guiding stent sizing during intervention.
- Venography shows the stenosis and collateral formation.
Interventional management
For symptomatic compression, angioplasty and placement of a dedicated venous stent restore outflow. When May-Thurner presents with acute iliofemoral DVT, thrombus removal (catheter-directed thrombolysis or mechanical thrombectomy) is combined with stenting of the underlying lesion. Dedicated venous stents provide the crush resistance and diameter needed for the iliac segment, distinct from arterial designs.
Outcomes and follow-up
Reported outcomes after stenting show durable symptom relief and good patency when the lesion is fully treated, with IVUS-guided sizing improving results. Antithrombotic therapy and imaging surveillance support long-term stent patency.
INVAMED technologies in this space
INVAMED offers dedicated venous stents and thrombectomy platforms; explore the venous stents category and the deep vein thrombosis category.
Device availability and approved indications vary by country. This content is prepared for healthcare professionals and does not replace clinical judgment or the instructions for use.