Changes in flow and pressure due to rotation of a saphenous vein segment

The effect of axial rotation on flow through and pressure gradient across saphenous vein segments was studied using 15 cadaver long saphenous veins. A significant reduction in flow occurred at a mean rotation of 25 degrees/cm and a significant increase in head loss across the segments occurred at a mean rotation of 23 degrees/cm. Collapse of the vein segments occurred at a mean rotation of 27 degrees/cm.