Changes of the soluble fibrin monomer complex level during the perioperative period of hip replacement surgery

BACKGROUND: Venous thromboembolism (VTE) is a critical complication after hip replacement surgery, so both early diagnosis and prophylaxis are important. The purpose of this study was to clarify the rapid changes of the fibrin monomer complex (FMC) and soluble fibrin (SF) during the perioperative period of hip replacement surgery. METHODS: The subjects were 32 patients (7 men, 25 women) who underwent elective hip replacement surgery between November 2004 and January 2006. Their ages ranged between 34 to 82 years (mean 56.8 years). According to their thromboembolic risk, the patients received different prophylaxis: unfractionated heparin (4 patients), danaparoid sodium (14 patients), or mechanical therapy only (14 patients). RESULTS: FMC and SF became rapidly elevated during the operation and just after surgery but declined to preoperational levels 3 days after surgery; they were higher in lupus anticoagulant (LA)-positive patients. In contrast, FDP and D-dimer had gradually become elevated 3 and 7 days after surgery. According to venous ultrasonography and lung perfusion scintigraphy, VTE occurred in 7 patients overall (21.9%). The incidence of VTE was 7.1% in the danaparoid group, whereas it was 35.7% in the mechanical therapy group. We also found that danaparoid sodium rapidly decreased FMC and SF within 3 days. CONCLUSIONS: FMC and SF were rapidly elevated during hip replacement surgery and differentiated in LA-positive and LA-negative patients.