Prolonged Prophylaxis with Unfractioned Heparin Is Effective to Reduce Delayed Deep Vein Thrombosis in Total Hip Replacement

Abstract

The aim of this study was to assess the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) until 45 days after elective total hip replacement (THR) and the efficacy of prolonged unfractioned heparin (UH) prophylaxis up to postoperative day 30. To this end 79 of 96 patients admitted consecutively to the University Hospital of Pisa for THR were randomly assigned to short- or long-term UH prophylaxis. Sixty-one patients completed the study: 28 of them received short-term prophylaxis (subcutaneous UH 15,000 IU/24 h for 15 days) and 33 prolonged prophylaxis (subcutaneous UH 15,000 IU/24 h for 30 days). Lower limb 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-treated patients; although the difference was only close to significance (p = 0.085), the relative risk of developing proximal DVT was about six times greater in the former group of patients. We concluded that the risk for thromboembolism persists at least until 45 days after surgery in patients subjected to THR. Prophylaxis with UH given up to postoperative day 30 appears more effective and safer in reducing the delayed thromboembolic risk compared to prophylaxis with UH given up to discharge only.

Prophylaxis of Deep Vein Thrombosis in Total Hip Replacement:Which Heparin and What Duration?

“…Two recent studies [9,10] demonstrated that the continuation of prophylactic anticoagulation with lowmolecular-weight heparin after total hip replacement during 1 full month postoperatively significantly reduced the prevalence of deep vein thrombosis. Importantly Manganelli et al [6] observed in their study that this was also true for unfractionated heparin and that such prolonged anticoagulant therapy did not increase hemorrhagic complications.…”

“…The mechanical approach evaluated for total hip replacement is intermittent pneumatic leg compression [4] which significantly reduced the prevalence of proximal deep vein thrombosis from 27 to 14% after total hip replacement in a randomized trial involving 310 patients. The pharmaceutical approach includes unfractionated heparin [5] which was the prophylaxis considered in the report of Manganelli et al [6], warfarin [3], low-molecular-weight heparin [7] and a more recent drug, recombinant hirudin [8].…”

“…In addition to its efficacy and safety, the advantages of such a prophylaxis are that first, it does not require laboratory monitoring and second, as pointed out by Manganelli et al [6], its cost is low. Although low-molecular-weight heparin tends to be the standard regimen of prophylaxis of deep vein thrombosis in patients undergoing total hip replacement, low-dose unfractionated heparin is still widely used in Europe.…”

“…Finally, the regimen tested by Manganelli et al [6], 15,000 IU/day of unfractionated heparin, costs approximately one third of the regimen of low-molecular-weight heparin. This latter prophylaxis is frequently preferred by orthopedic surgeons although its superiority in terms of efficacy has never been demonstrated in the prophylaxis of deep vein thrombosis after total hip replacement.…”

“…This latter prophylaxis is frequently preferred by orthopedic surgeons although its superiority in terms of efficacy has never been demonstrated in the prophylaxis of deep vein thrombosis after total hip replacement. Therefore as proposed by Manganelli et al [6] a large prospective randomized trial comparing efficacy and costeffectiveness of prolonged prophylaxis of these two regimens would be of great interest. …”