Objective: To investigate the effect of lightweight graduated elastic stockings on venous haemodynamics.
Design: The amount of reflux and function of the calf muscle pump were evaluated before and after the application of lightweight graduated compression stockings using air-plethysmography. Each patient acted as his own control and the Wilcoxon rank sum test was used.
Setting: Vascular laboratory of a teaching hospital.
Subjects: 19 female patients (20 limbs) with moderate varicose veins.
Main outcome measures: The haemodynamic parameters: amount of reflux (VFI), ejection fraction (EF) of the calf muscle pump after one tiptoe exercise, residual volume fraction (RVF) after 10 tiptoes and venous volume (VV) were determined for each patient with and without the three strengths of stocking (7, 10, 14 mmHg at the ankle) using air-plethysmography.
Results: The mean VFI decreased from 5.7 ml/sec without stockings to 4.6+/-2.2, 3.9+/-2.3, and 3.4+/-1.8 with stockings of 7, 10 and 14 mmHg respectively (p<0.0002). Similarly the RVF showed a significant decrease with all three stockings from the initial value 42.3% to 36.3, 34.4 and 31.5 respectively (p<0.03). EF showed an increase from 49.2% to 51.4, 50.9 and 56, but only with the latter was the increase significant (p<0.02). VV decreased from 118.8 ml to 113.6+/-24.4 (p>0.05), 104.2+/-22.8 and 109.1+/-27.4 (p<0.008) with 10 and 14 mmHg.
Conclusions: The results indicate that lightweight compression stockings can have a significant effect on venous haemodynamics. They decrease the residual volume fraction and by inference ambulatory venous pressure. This is the result of an increase in the ejection fraction with a decrease of reflux. The results offer a possible physiological explanation on the relief of symptoms experienced when patients with varicose veins wear lightweight stockings.