Venous haemodynamics in the legs after ligation of the inferior vena cava.

Doppler ultrasound and strain gauge plethysmography (SGP) were used to study venous insufficiency in 22 patients after ligation of the inferior vena cava (LIVC), 13 control patients with unilateral postthrombotic syndrome (PS) and 20 normal controls. Isotope venography was performed in eight patients. SGP showed low venous capacity in LIVC legs without deep vein thrombosis (DVT), indicating restrictive syndrome. There was no venous obstruction in any of the groups studied. In the LIVC limbs with DVT and in the PS limbs, venous reflux differed significantly from that of normal controls. The popliteal venous reflux examined by Doppler ultrasound was sporadic in LIVC limbs without DVT, occurring in 71% of LIVC limbs with DVT and in 77% of limbs with PS. Isotope venography in eight LIVC patients showed abundant collateral circulation. We conclude that DVT causes venous reflux. LIVC causes a restrictive syndrome without venous obstruction, and alone it did not cause venous reflux. Clinically it indicates that symptoms after uncomplicated LIVC are mild and that late postoperative morbidity is principally arising from DVT and not from LIVC alone.