February 22, 1985

Prophylaxis of Postoperative Deep Venous Thrombosis-Reply

Author Affiliations

Veterans Administration Medical Centers West Roxbury/Brockton, Mass
Sandoz Inc East Hanover, NJ

JAMA. 1985;253(8):1120. doi:10.1001/jama.1985.03350320040008

In Reply.—  In comparison with the beneficial results of dihydroergotamine-heparin combination in preventing deep vein thrombosis in patients undergoing elective general surgery,1 Drs Wille-Jørgensen et al cite their study2 in which the combination therapy was not significantly superior to subcutaneously administered heparin alone. In addition, they question the validity of using the RFUT leg scan technique for diagnosing deep vein thrombosis, citing the number of false-positive results in their study, particularly in the heparin-alone group.There are several important points of difference between our two trials that we believe account for the differing significance of the results. First, as Dr Wille-Jørgensen and colleagues initially calculated, the number of patients planned for accession into their trial to achieve statistical significance was much larger than was actually accessed (125 patients for each group planned, in contrast to only 100 patients entered into the dihydroergotamine-heparin group and 81 in the heparin-alone