What are the long-term outcomes of iliac-vein stenting in young patients (under 45 years) with May-Thurner syndrome?

Long-Term Iliac Vein Stent Outcomes in Young May-Thurner Patients

Iliac vein stenting for May-Thurner syndrome in young patients demonstrates excellent long-term durability with primary patency rates of 84-93% at 2-3 years and secondary patency exceeding 95%, making it the definitive treatment when combined with thrombolysis for acute DVT or as standalone therapy for chronic venous obstruction. 1, 2

Evidence for Long-Term Patency

The data specifically addressing young patients is robust and reassuring:

• In adolescents and young adults (ages 12-20 years), primary patency at 24 months reaches 88.9% for non-thrombotic lesions and 84.4% for thrombotic presentations, with overall patency (including reinterventions) of 95.4% and 96.9% respectively. 2

• Technical success rates exceed 98% in young patients, with clinical symptom improvement achieved in 93-94% of cases. 2

• The 3-year data from large series show sustained symptom relief, with 79% maintaining pain reduction and 66% maintaining swelling reduction at 3 years. 3

Critical Age-Related Considerations

Young patients warrant special attention because:

• Patients under 50 years presenting with claudication or venous symptoms may have more aggressive disease, but venous stenting outcomes remain excellent—unlike arterial interventions which perform worse in this age group. 3

• Young, otherwise healthy patients with acute left-sided DVT should immediately raise suspicion for May-Thurner syndrome, as anatomic compression is more prevalent in this population. 1

• The anatomic compression persists despite anticoagulation alone, making mechanical relief essential to prevent recurrent VTE. 1

Treatment Algorithm for Young Patients

Acute Presentation (DVT <14 days):

• Initiate therapeutic anticoagulation immediately with unfractionated heparin or LMWH. 1

• Perform catheter-directed thrombolysis (CDT) or pharmacomechanical thrombectomy (PMT) to remove thrombus burden before stenting (Class IIa recommendation). 3, 1

• Pharmacomechanical thrombectomy reduces thrombolytic drug dose by 40-50% and shortens infusion time compared to CDT alone. 1

• After thrombus removal, perform balloon angioplasty followed by self-expanding stent placement—angioplasty alone typically fails. 1

Non-Thrombotic or Chronic Presentation:

• Proceed directly to venography with intravascular ultrasound (IVUS) to confirm >50% stenosis. 4

• Stent placement without preceding thrombolysis achieves 83-98% anatomic success for chronically occluded iliac veins. 3

• This approach significantly improves quality of life scores and enables venous ulcer healing in 56% of affected patients. 3

Technical Specifications

• Confine stents to the iliac vein whenever feasible to optimize patency. 3

• If the lesion extends into the common femoral vein, caudal stent extension is reasonable but expect modestly reduced patency (90% vs 84%). 3

• Self-expanding bare-metal stents are the standard choice, with average sizes ranging 12-16mm depending on vessel diameter. 2, 4

Post-Stenting Management for Young Patients

Anticoagulation Protocol:

• Continue therapeutic anticoagulation with the same dosing, monitoring, and duration as iliofemoral DVT patients without stents—minimum 3 months, indefinite for unprovoked events. 3, 1

• Direct oral anticoagulants are preferred over warfarin in non-cancer patients due to lower bleeding risk. 1

• Add antiplatelet therapy to anticoagulation in high-risk patients (poor inflow, suboptimal result) after individualized bleeding assessment. 3

Compression Therapy:

• Prescribe 30-40 mmHg knee-high elastic compression stockings for at least 2 years to reduce post-thrombotic syndrome risk. 1

Timing of Complications

A critical finding for counseling young patients:

• When stent complications occur, they manifest early—within the first year, particularly within the first 4 months. 5

• If initial luminal patency is achieved, it remains well-maintained during long-term follow-up with no new in-stent stenosis developing after the first year. 5

• Stent fracture is rare (~1% of cases) and can be successfully managed with a second stent when it occurs. 3

Special Situations in Young Patients

Pregnancy Considerations:

• In 62 women with left iliac vein stents who later became pregnant and received LMWH prophylaxis, zero experienced recurrent VTE during pregnancy or postpartum. 3

• Mechanical stent deformation may occur on duplex ultrasound late in pregnancy but resolves spontaneously postpartum without clinical sequelae. 3

Limb-Threatening Presentation:

• For phlegmasia cerulea dolens, CDT or PCDT is a Class I (mandatory) recommendation—anticoagulation alone is inadequate and risks limb loss. 1

Common Pitfalls to Avoid

• Do not rely on anticoagulation alone when May-Thurner is identified; the persistent anatomic compression predisposes to recurrent VTE regardless of anticoagulation adequacy. 1

• Do not delay endovascular intervention; early thrombus removal within 14 days yields optimal outcomes. 1

• Do not dismiss symptoms in young patients as musculoskeletal—left-sided leg swelling in young women has 4.88 times higher odds of being May-Thurner compared to right-sided or male presentations. 4

• Procedural bleeding complications during CDT are rare (1-4%), and thrombolysis-related bleeding is essentially absent with modern pharmacomechanical techniques. 2, 6

Surveillance Protocol

• Perform duplex ultrasound at 3,6,12, and 24 months to evaluate venous patency and stent function. 7

• CT venography can be used selectively for comprehensive evaluation of stent morphology and surrounding anatomy. 5