Pneumatic Compression Versus Low Molecular Weight Heparin in Gynecologic Oncology Surgery: A Randomized Trial

Abstract

Venous thromboembolism is a dangerous postoperative complication that occurs in as many as 14% of patients after gynecologic surgery and 38% of women after surgery for gynecologic oncology. To study the value of low-molecular-weight heparin in preventing thromboembolism, the authors conducted a randomized trial comparing the efficacy and complication rates of low molecular-weight heparin and external pneumatic compression in women scheduled to undergo gynecologic oncology surgery at Duke Medical Center. Patients randomly assigned to external pneumatic compression were placed in sleeves before surgery and wore them for the first 5 days and thereafter until they were ambulatory. Patients receiving low-molecular-weight heparin were given 2500 units subcutaneously 1 to 2 hours before surgery and again 12 hours after surgery. They received 5000 units daily for the first 5 postoperative days and each day thereafter until discharge. On the third to the fifth postoperative day, all patients were evaluated for the presence of occult deep vein thrombosis using bilateral Doppler ultrasound. In addition, each patient was interviewed by phone 1 month after surgery and asked about signs and symptoms suggestive of thrombosis. In the perioperative period, proximal lower extremity deep vein thrombosis was diagnosed in three women, one in the pneumatic compression group and two in the low molecular-weight heparin group. All were asymptomatic. The estimated blood loss at surgery, intraoperative and postoperative transfusions, and other complications were similar for both groups. The low molecular-weight heparin was discontinued in three patients who had excessive bleeding during surgery and in one patient whose platelet count dropped to less than 60. On the first postoperative day, low platelet counts (below 100,000) were seen in five women in the low molecular-weight heparin group and one in the external pneumatic compression group. On day three, low platelets were seen in six patients in the pneumatic compression group and two in the low molecular-weight heparin group. Linear regression analysis of laboratory values, including hematocrit, platelet count, and activated thromboplastin, found that the final postoperative hematocrit was significantly higher in the women with external pneumatic compression (P = .004). The maximum activated thromboplastin time was significantly higher in the women receiving low molecular-weight heparin (P = .01).