Coe NP, Collins RE, Klein LA, Bettmann MA, Skillman JJ, Shapiro RM, Salzman EW.
Prevention of deep vein thrombosis in urological patients: a controlled,
randomized trial of low- dose heparin and external pneumatic compression boots.
Surgery 1978 Feb;83(2):230-4

A prospective, randomized clinical trial in 83 patients undergoing open urological
operations was performed to compare the relative prophylactic efficacy of low-dose
heparin and external pneumatic compression (EPC) of the calves in comparison to no
treatment in the prevention of deep vein thrombosis (DVT). The diagnosis of deep
vein thrombosis was established by the I125 fibrinogen scan and contrast phlebography.
The data indicate that EPC is more effective than no treatment (p less than 0.04)
and more effective than low-dose heparin (p less than 0.04) in the prevention of DVT.
There was one pulmonary embolus in each of the three groups, and in the treatment
groups this occurred without evidence of DVT.