Postoperative deep vein thrombosis of the lower limb and prophylactic value of heparin evaluated by phlebography

The incidence of postoperative thrombosis of the leg at phlebography, and the prophylactic effect of low-dose heparin, was assessed in a double-blind investigation comprising 50 patients. Thrombosis occurred in 17 per cent in the heparin group and in 23 per cent in the placebo group. This difference is not significant. No prophylactic effect of low-dose heparin was demonstrated.