PROLONGED PROPHYLAXIS WITH UNFRACTIONED HEPARIN IS EFFECTIVE TO REDUCE DELAYED DEEP-VEIN THROMBOSIS IN TOTAL HIP-REPLACEMENT

The aim of this study was to assess the incidence of deep vein thrombo sis (DVT) and pulmonary embolism (PE) until 45 days after elective tot al hip replacement (THR) and the efficacy of prolonged unfractioned he parin (UH) prophylaxis up to postoperative day 30, To this end 79 of 9 6 patients admitted consecutively to the University Hospital of Pisa f or THR were randomly assigned to short- or long-term UH prophylaxis, S ixty-one patients completed the study: 28 of them received short-term prophylaxis (subcutaneous UH 15,000 IU/24 h for 15 days) and 33 prolon ged prophylaxis (subcutaneous UH 15,000 IU/24 h for 30 days). Lower li mb phlebography was performed in all patients on day 45 after THR. DVT was demonstrated in 10 (16.3%) cases after hospital discharge. Among them, 2 patients also had symptomatic PE. The incidence of DVT was 21. 4% in short- and 12.1% in long-term UH-treated patients. The incidence of only proximal DVT was 17.8% in short- and 3.0% in long-term UH-tre ated patients; although the difference was only close to significance (p = 0.085), the relative risk of developing proximal DVT was about si x times greater in the former group of patients. We concluded that the risk for thromboembolism persists at least until 45 days after surger y in patients subjected to THR. Prophylaxis with UH given up to postop erative day 30 appears more effective and safer in reducing the delaye d thromboembolic risk compared to prophylaxis with UH given up to disc harge only.