What is the management plan for a patient with a prominent left iliac artery on ultrasound, presenting with scrotal and penile edema, and left leg edema?

Management of Suspected Nonthrombotic Iliac Vein Lesion (NIVL)

This patient's presentation of left leg edema with scrotal and penile edema in the setting of a prominent left iliac artery strongly suggests a nonthrombotic iliac vein lesion (NIVL), where the left common iliac vein is compressed between the right common iliac artery and the vertebral body, and requires confirmatory imaging with venography and intravascular ultrasound (IVUS) to determine if endovascular stenting is warranted. 1

Initial Diagnostic Workup

Exclude other causes of edema first before pursuing invasive evaluation for NIVL:

• Rule out systemic causes including medications (calcium channel blockers), heart failure, renal disease, liver disease, and hypoproteinemia 1
• Exclude primary lymphedema as a cause of the asymmetric edema 1
• Perform venous duplex ultrasound to assess for superficial venous reflux and deep venous thrombosis 1
• Note that bilateral edema is rarely caused by NIVL; this patient's asymmetric left-sided presentation is consistent with NIVL 1

Confirmatory Imaging Strategy

If clinical suspicion remains high after excluding other causes, proceed with definitive imaging:

• Venography with IVUS is the gold standard for diagnosis and is mandatory before any intervention 1
• IVUS is superior to venography alone, detecting 30% more stenotic lesions ≥50% compared to venography 1
• A diameter stenosis >61% on IVUS is the threshold most predictive of clinical success with intervention 1
• CT venography may identify anatomic compression (24% of asymptomatic patients have >50% compression on CT), but does not predict symptoms and should not be used alone for treatment decisions 1, 2
• Ultrasound can suggest NIVL but lacks the precision needed for treatment planning 3

Patient Selection for Stenting

This patient meets criteria for potential stent placement based on the 2024 VIVA/American Venous Forum/American Vein and Lymphatic Society consensus guidelines:

• Stent placement is appropriate for asymmetrical edema significantly affecting quality of life after excluding other causes 1
• The presence of scrotal and penile edema indicates significant venous outflow obstruction affecting quality of life 1
• Stenting is inappropriate if symptoms are minimal or in asymptomatic patients as prophylaxis 1

Technical Considerations for Stent Placement

If IVUS confirms >61% diameter stenosis and symptoms warrant intervention:

• IVUS measurements must guide stent sizing, using the normal reference vessel (external iliac vein) for diameter selection 1
• Avoid using prestenotic dilated segments for sizing, as this can lead to undersizing 1
• Stent length should be ≥60 mm to minimize migration risk; stents <60 mm accounted for 82.6% of migrations with 16.2% mortality 1
• Extend stents into the straight portion of the external iliac vein to prevent migration 1
• Oversize by 1-4 mm compared to the reference vessel diameter per manufacturer instructions 1

Post-Procedure Management

Anticoagulation and antiplatelet therapy are NOT routinely required:

• No consensus supports routine anticoagulation or antiplatelet therapy for treated NIVL without prior venous thromboembolism 1
• High patency rates are achieved without antithrombotic therapy 1
• If other thrombotic risk factors exist (cancer, inherited thrombophilia, inflammatory conditions), these take precedence over the stent for determining anticoagulation need 1

Surveillance Protocol

Routine clinical and imaging surveillance is mandatory:

• Perform regular follow-up with imaging (ultrasound or CT) per practitioner preference 1
• Monitor specifically for stent migration and stenosis/thrombosis 1
• Clinical improvement in edema and quality of life should be evident if intervention was appropriate 1

Critical Pitfalls to Avoid

• Do not treat based on CT or ultrasound findings alone—IVUS confirmation is essential 1
• Do not intervene on dynamic lesions that vary with breathing or position; only fixed lesions warrant treatment 1
• Do not use stents <60 mm in length due to catastrophic migration risk (56% migrate to heart, 24% to pulmonary artery) 1
• Do not assume anatomic compression equals symptomatic disease—up to 70% of asymptomatic individuals have some degree of iliac vein compression 1, 2