PREVENTION OF POSTOPERATIVE VENOUS THROMB OSIS - A RANDOMIZED TRIAL COMPARING LOW-DOSE HEPARIN AND LOW-MOLECULAR-WEIGHT HEPARIN IN GYNECOLOGICAL ONCOLOGY

In a prospective double-blind randomised study the efficacy and safety of a low molecular weight heparin (LMWH) and unfractionated heparin ( UFH) were compared in the use of perioperative prophylaxis for thrombo sis in gynaecological patients undergoing major gynaecological cancer surgery. Three hundred and thirty patients were randomly allocated to the two prophylactic groups; 6 of these were dropouts of the study. Of the remaining 324 patients 160 received 3000 IU of low molecular weig ht heparin and 164 received subcutaneously 5000 IU unfractionated hepa rin 3 times a day (low dose heparin). Treatment was initiated 2 h preo peratively and continued for 7 days. The occurrence of deep vein throm bosis (DVT) was determind by impedance plethysmography (IPG) and phleb ography. DVT was diagnosed in 10 of 160 patients (6.3%) treated with l ow molecular weight heparin and in 10 of 164 patients (6.1%) treated w ith low-dose heparin. DVT of proximal veins (including poplitea area) was detected in 4 patients of the LMWH group and in seven patients of the UFH group. During the observation (until 10(th) postoperative day) 7 pulmonary embolism -1 fatal and 6 unfatal - occurred in patients rec eiving prophylaxis with LMWH and 4 pulmonary embolisms (all unfatal) o ccurred in the UFH group. The incidence of wound haematoma (p = 0.01) and blood transfusions (p = 0.0005) were statistically significantly i ncreased in the UFH group. The results of this trial demonstrate that the low molecular weight heparin is as effective and safe as low dose heparin preventing DVT, but the incidences of bleeding complications w ere higher in the group with unfractionated heparin.