Unexpectedly high rate of phlebographic deep venous thrombosis following elective general abdominal surgery among patients given prophylaxis with low-molecular-weight heparin
H. Bounameaux, O. Huber, E. Khabiri, P. A. Schneider, D. Didier and A. Rohner
Department of Medicine, University Hospital of Geneva, Switzerland.
One hundred ninety-four patients undergoing elective general abdominal
surgery were randomized in a single-blind study to receive one daily
subcutaneous injection of a low-molecular-weight heparin, dalteparin sodium
(2500 IU, n = 97) or nadroparin calcium (3075 IU, n = 97), two regimens
that are approved in Europe to prevent deep venous thrombosis. On the eight
postoperative day, bilateral ascending leg phlebography (n = 185) showed
the presence of deep venous thrombosis in 45 cases (24.3%; 95% confidence
interval, 18% to 31%), with a significantly higher rate (on
intention-to-treat) among the patients who received the lower dosage (30 vs
15 deep venous thromboses). We conclude that the two regimens of
low-molecular-weight heparin that were used in this study failed to prevent
postoperative phlebographically proved deep venous thrombosis in one of
four patients.
