A Study of Tourniquets in the Investigation of Venous Insufficiency

Abstract

Tourniquets are used extensively in the assessment of the venous system. They are employed not only for clinical tourniquet tests but are also used during examinations by Doppler ultrasound, plethysmography and venography, and during ambulatory venous pressure measurements. Surgical management is based on conclusions reached by the use of tourniquets. This study was undertaken to evaluate the pressure required to prevent reflux in the incompetent long saphenous vein. A total of 44 limbs with sapheno–femoral incompetence were studied. Duplex doppler ultrasound was used to detect retrograde flow within the long saphenous vein during inflation of a 2.5 cm wide pneumatic tourniquet applied around the thigh. The pressure required to prevent reflux, the diameter of the imaged vein and the circumference of the thigh were measured. The pressure required to prevent reflux varied from 40 mmHg to 300 mmHg. There was a correlation between this pressure and the circumference of the thigh ( r = 0.62 P < 0.001). There was no correlation with the diameter of the vein. In conclusion, tourniquets introduce a source of error into evaluation of venous disease.