title: Compression stockings with a negative pressure gradient have a more pronounced effect on venous pumping function than graduated elastic compression stockings.
abstract: OBJECTIVE
  To measure the effect on the venous pumping function of a stocking providing a negative pressure gradient with higher pressures over the calf in comparison to a conventional graduated elastic compression stocking (GECS) in patients with advanced venous insufficiency.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  30 patients with severe superficial chronic venous insufficiency were enrolled. Two elastic stocking designs exerting a pressure at ankle between 15 and 25 mm Hg were compared; a conventional GECS and a stocking exerting a higher pressure over the calf than over the ankle producing a "progressive" increase in compression (PECS).
  
  
  METHODS
  the venous calf pumping function was assessed by measuring the ejection fraction (EF) from the lower leg by a plethysmographic method during a standardised exercise. Interface pressure of the 2 compression devices was simultaneously recorded both at B1 = 12 cm above ankle, C = just above widest part of calf.
  
  
  RESULTS
  The mean increase of EF produced by PECS was +75% (95 CI 48, 7-101,3) compared with +32% (95% CI 16, 8-48,6) with GECS (P < 0.001). There was a significant correlation between EF and the stocking pressure measured at calf level during standing and walking.
  
  
  CONCLUSIONS
  Stockings exerting a higher pressure on the calf than on the ankle show a greater efficacy in increasing the venous ejection fraction from the leg.
authors: Clinica MD Barbantini, Via del Calcio n.2, 55100 Lucca, Italy. jmosti@tin.it
authors: G
authors: G
authors: Mosti
authors: H
authors: H
authors: Partsch