Moser G, Krahenbuhl B, Donath A.
[Prevention of deep venous thrombosis (TVP) and pulmonary embolism. Comparison of
heparin (3 x 5000 IU/day), heparin (2 x 5000 IU/day) + 0.5 mg dihydroergot, and
physiotherapy (intermittent compression stockings + physical exercise).
Value of Doppler diagnosis in systematic detection of TVP compared with
phlebography and scanning of the legs using labelled fibrinogen]
Helv Chir Acta 1980 Jun;47(1-2):145-9

We compared the protective value of the above treatments in 227 randomised
patients. Investigations in each patient included pulmonary scanning before and
after operation, repeated postoperative Doppler and radioactive limb scanning
completed by phlebography to confirm positive results. The heparin DHE group and
the "physiotherapic" group each totalized 76 patients and the heparin group 75.
These comparable groups show that HDHE and heparin prophylaxis are identical; but
physiotherapy is perhaps better. Compared with phlebography leg scanning
sensitivity is 95%, whilst it's specificity is 99%. Doppler sensitivity is only
of 21%, whilst it's specificity is 95%. In conclusion, "physiotherapic"
prophylaxis, including Flowtron, is as effective as heparin alone. Doses of
heparin may be reduced, without loss of effect, if supplemented by a
veinoconstrictive agent as DHE. The low Doppler sensitivity contraindicates its
use in asymptomatic DVT detection.