The graphic recording of the rate of drainage of blood from the veins of the legs

The purpose of this technique was to devise a method to study certain aspects of the aetiology of varicose veins in pregnancy and whether the developing foetus causes a mechanical obstruction of the venous drainage of the lower limbs. Such a technique might be of use in the study of other clinical conditions. The technique to be described is for the graphic recording of the rate of venous drainage from the legs by gravity. The procedure involves the use of a tilting table and a limb plethysmograph. The initial angle of the limb volume change following the completion of the tilting was recorded and from this the venous drainage rated was calculated. The results indicate the freedom with which venous drainage occurs and the lack of resistance that exists to the venous outflow from the lower limbs. The validity of the measurements derived from the technique was examined by causing venous obstruction by a positive Valsalva procedure and by examining the records during and after pregnancy. Other techniques have been evolved to investigate the part played in the production of varicose veins by: (1) changes in venous valvular competency and (2) venous tone (AU)