Venous stent patency may be affected by collateral vein lumen size

PURPOSE: Deep venous thrombosis causes blood flow deviation. It is hypothesized that with stent placement, developed collateral veins become redundant. This article evaluates the relation between the surface area of the collaterals and stent patency. METHODS: The azygos and hemiazygos veins were identified and the largest surface area was measured at thoracic level. Patency rates of stented tracts were evaluated and related to collateral vein lumen size. RESULTS: The vena cava occlusion and the azygos and hemiazygos vein surface area measurements were positive and statistically significant related (OR 1.01, 95% CI 1.003−1.019, p = 0.004) respectively (and OR 1.007, 95% CI 1.001−1.013, p = 0.004). An azygos surface area measurement of 23 (p<0.001) and hemiazygos surface area measurement of 40 (p = 0.008) was shown as cut-off point related to higher occlusion rates. CONCLUSIONS: The surface area of major venous collateral pathways seems to be related to stent occlusion in deep venous interventions.