Postoperative deep vein thrombosis in patients with colorectal cancer.

Deep vein thrombosis (DVT) is reported to be common among patients undergoing surgery for colorectal cancer. This randomized controlled trial was aimed to determine the efficacy of low molecular-weight heparin in the prophylaxis of DVT in this high-risk group and was truncated early in view of an unexpectedly low incidence of DVT. Between March 2002 and January 2004, a total of 99 patients with colorectal cancer - selected for surgery in the lithotomy position - were randomized before surgery to either receive dalteparin or no drug (51 and 48 patients, respectively) during the perioperative period. Duplex ultrasonography was performed before and after the surgery. We also looked for distal venous thrombosis, pulmonary embolism, hemorrhage and any mortality. No episode of DVT occurred in either the drug arm or the observation arm. There was no death following surgery. The incidence of DVT in Indian patients operated for colorectal cancer in the lithotomy position was negligible.