Long-term clinical outcomes and technical factors with the Wallstent for treatment of chronic iliofemoral venous obstruction

Abstract

Background: Factors affecting long-term clinical outcome and stent patency after iliofemoral venous stenting remain complex and ill-defined. Also, consensus is lacking among clinicians regarding the continuing role for the Wallstent (Boston Scientific, Marlborough, Mass) as dedicated nitinol-based venous stents become available. We undertook this study to review our long-term results using Wallstents and to evaluate the potential role of this stent in the future.

Methods: From 2007 to 2014, there were 77 limbs in 67 consecutive patients that received Wallstents for chronic iliofemoral vein 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 (CEAP) classification. Clinical improvement was assessed with VCSS at 12, 24, and 36 months. VCSS change ≥4 points was considered significant improvement. Patency was assessed with duplex ultrasound. A retrospective review of patients' records and imaging was conducted to assess baseline and procedural factors associated with long-term clinical outcomes.

Results: 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 was 63 years (range, 47-83 years). Median baseline VCSS was 9 (range, 3-23). IVUS and venography estimated equal vessel compromise length in 37 limbs (48%). IVUS estimated a longer lesion in 32 limbs (42%). Stenting correlated with venography and IVUS in 37 limbs (48%) and more closely aligned with IVUS 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 (97%) 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 both 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. Eight patients required reintervention (range, 0.5-80 months); five interventions were to maintain patency. Cox multivariate regression identified that CFV disease predicted later complications. At last VCSS follow-up per patient (median, 26 months), 52 patients (68%) showed ≥4-point VCSS improvement. None had score worsening.

Conclusions: Venous stenting with Wallstents for iliofemoral post-thrombotic or compressive obstruction proved safe and effective through long-term follow-up, with excellent patency rates. The majority of patients exhibited significant clinical improvement. CFV occlusive disease predicts increased complications.

Keywords: IVUS; Iliofemoral veins; Nonthrombotic; Post-thrombotic; Venous stent; Wallstent.