Biometry of infrarenal inferior vena cava measured by cavography

Placement of a transvenous vena cava filter has became a common way to control recurrent pulmonary embolism. However few studies have been reported on the diameter of the infrarenal inferior vena cava (IIVC) where the device is usually placed. This study based upon 100 cavographies has showed the calculated average diameter of IIVC was 20.9 mm (range 12–27 mm) in its middle part and 21.3 mm (range 10–31 mm) in its terminal end. The calculated average IIVC length was 96 mm (range 80.3–142 mm). There was no statistical correlation between caval size and age, sex, height, weight and corporeal area. There was a statistical difference of left renal vein location between patients presenting with lumbar arthrosis and those without. We discuss different methods to measure IIVC in particular tomodensitometry. CT scans reviewed in our department show that the largest diameter of IIVC is not in a frontal plane and that the width seen on cavography is the projection of the largest diameter on the film. Therefore, the range of the real caval diameters is greater than indicated above.