Low molecular weight heparin and prevention of postoperative thrombosis in abdominal surgery

In a prospective, double-blind, randomized multicenter trial the efficacy and safety of low melecular weihgt heparin and unfractionated heparin were compared for the prevention of postoperative deep vein thrombosis in patients undergoing abdominal surgery. Six hundred and seventy-three patients were randomly allocated to the two prohylaxis groups; 20 of these, however, did not undergo surgery and did not receive any prophylaxis