Reduction of Out-of-Hospital Symptomatic Venous Thromboembolism by Extended Thromboprophylaxis With Low-Molecular-Weight Heparin Following Elective Hip Arthroplasty

Abstract

ELECTIVE TOTAL hip arthroplasty is a major risk factor for venous thromboembolism.¹ Low-molecular-weight heparin is an effective method of thromboprophylaxis, resulting in a reduction of approximately two thirds in proximal deep vein thrombosis.¹ When the original controlled trials that showed the efficacy of low-molecular-weight heparin following total hip arthroplasty were conducted, the usual duration of therapy, which coincided with the duration of hospital stay, was 7 to 12 days.¹ The length of hospitalization following total hip arthroplasty has decreased during the last decade, and it is now necessary for many patients to receive antithrombotic therapy following discharge to receive the minimum recommended 7 to 10 days of prophylaxis. More recently, studies^2-8 have reported that prophylaxis with extended out-of-hospital low-molecular-weight heparin for an additional 4 to 6 weeks further reduces venous thromboembolism following hip arthroplasty. Meta-analyses suggest that such regimens of prophylaxis reduce the risk of both asymptomatic deep vein thrombosis (ie, diagnosed by screening venography) and symptomatic venous thromboembolism by approximately 60%.^9-11