A 7-Year Single-Center Experience With the Wallstent as Treatment for Chronic Iliofemoral Venous Obstruction: Long-Term Clinical and Technical Outcomes

Abstract

Factors affecting long-term clinical outcome and stent patency after iliofemoral venous stenting remain complex and ill-defined. There is also a lack of consensus among clinicians regarding whether there is a continuing role for the Wallstent (Boston Scientific, Marlborough, Mass), the historical choice for iliofemoral stenting, as new nitinol stents become available. We undertook this study to review our long-term results using Wallstents and to evaluate the role of this stent in the future. From 2007 to 2014, in 67 consecutive patients, 77 limbs were implanted with Wallstents for chronic iliofemoral venous obstruction. Intravascular ultrasound (IVUS) and venography were used to assess lesion type and extent. Baseline clinical severity was assessed with Venous Clinical Severity Score (VCSS) and Clinical, Etiology, Anatomy, and Pathophysiology classification. Clinical improvement was assessed with VCSS at 12-, 24-, and 36-month follow-up. VCSS score change ≥4 points was considered significant clinical improvement. Patency was assessed with duplex ultrasound. A retrospective review of patient records and imaging was conducted to assess baseline and procedural factors associated with long-term clinical outcomes. Lesions were nonthrombotic in 42 limbs (55%) and left sided in 48 limbs (62%). Ten patients were treated for bilateral venous disease. Patients were predominantly male (55%); median age of the patients was 63 years (range, 47-83 years). Baseline VCSS was 9 (range, 3-23). IVUS and venography estimated equal vessel involvement in 37 limbs (48%). IVUS estimated a longer lesion than venography in 32 limbs (42%). Stenting correlated with both venographic and IVUS assessment in 37 limbs (48%) and more closely aligned with IVUS findings in 35 limbs (45%). Stents extended into the common femoral vein (CFV) in 17 limbs (22%) and into the inferior vena cava in 6 limbs (8%). Sixty-five patients had available imaging follow-up (median, 50 months). At 72 months, primary patency in the overall cohort was 87%; assisted primary patency and secondary patency were 95%. In the nonthrombotic subset, assisted primary patency and secondary patency were 100%; primary patency was 97%. In the post-thrombotic subset, primary patency was 75%; assisted primary patency and secondary patency were 88%. Three early failures occurred. Cox multivariate regression identified post-thrombotic etiology and CFV disease as associated with later complications. A total of eight patients required reintervention during follow-up (range, 0.5-80 months); five were interventions to maintain patency. All patients had follow-up VCSS assessment at 12, 24, and 36 months. At last VCSS follow-up for each patient (median, 26 months), 52 patients (68%) showed ≥4-point VCSS improvement, and no patients had score worsening. Venous stenting with Wallstents for iliofemoral post-thrombotic or compressive obstruction proved safe and effective through midterm follow-up, with excellent patency rates and a majority of patients exhibiting significant clinical improvement. Analyses for stenosis and stenting in the iliofemoral tract should err with the imaging modality that captures the more severe lesion. Contralateral limb deep venous thrombosis due to “jailing” with inferior vena cava stent extension may be avoided by proper stent sizing. In post-thrombotic cases, anchoring the Wallstent in scar improves stent radial force and may improve long-term patency. Post-thrombotic etiology and CFV occlusive disease predict increased reintervention.