Iliofemoral venous stenting has become the standard of care for patients presenting with quality-of-life impairing symptoms of chronic iliofemoral venous obstruction (CIVO) not responding to conservative measures. This has led to the increased utilization of venous stenting over the last several years. However, iliofemoral venous anatomy in patients requiring such intervention remains poorly elucidated. This study attempts to fill that gap.

22 consecutive patients with IVUS confirmed CIVO underwent 3D reconstruction of their computed tomography venogram (CTV) images. Relevant angles, tortuosity (tort index – ratio between centerline length and straight line length), lengths and diameters were computed and analyzed. T-tests were used for comparison between the right and left sides. P<0.05 was considered significant.

Of the angles calculated, the median of the angles between the horizontal and CIV was 66° on the right and 60° on the left (p<0.01). The median IVC -CIV angle was 172° on the right and 165° on the left (p<0.0001). CIV-EIV angle was 159° on the right and 151° on the L (p=0.01). Overall, the median tortuosity was 1.07 on the right and 1.12 on the left (p=0.007). The median centerline length of the common iliac vein (CIV) was 42mm on the right and 60mm on the left (p<0.0001). The median external iliac vein (EIV) length was 73mm on the right and 88mm on the left (p<0.0001). The overall median iliac vein length was 220mm on the right and 237mm on the left (p<0.01). The median diameters of the IVC at the iliocaval confluence, 20mm, 40mm and 60 mm cranial to the confluence, were 23mm, 20mm, 22mm and 23mm respectively.

Overall, the left side has steeper angles, greater tortuosity and longer lengths than the right side. These disparities should be considered during femoroiliocaval stent construction.