Predictive value of fibrin monomers in postoperative deep vein thrombosis

Intravascular activation of the coagulation system produces disseminated intravascular coagulation or deep vein thrombosis and is characterized by the occurrence of circulating soluble fibrin monomer complexes (FM) in plasma. In order to evaluate the prognostic and diagnostic value of this parameter in 156 patients with fractures of the femur, neck of the femur, tibia, and fibula, and with knee-joint or elective hip surgery, soluble fibrin monomer complexes (FM) were determined using the FM Test from Boehringer Mannheim/Diagnostica STAGO (erythrocyte agglutination test according to Largo). Plasma samples were taken prior to and on the 1st, 2nd, 3rd, 5th, 7th, and 9th postoperative day. Diagnosis of DVT was carried out by 125-I-labelled fibrinogen test in parallel. Positive results were checked by phlebography on the 7th or 9th postoperative day. Positive FM results were obtained in only 26% of patients without DVT. In 34 of 36 patients (94%) with postoperative DVT confirmed by phlebography, on the other hand, elevated FM levels were detected 2-4 days before the 125-I-labelled fibrinogen test gave positive results. The predictive value calculated on the basis of elevated FM levels is 63-73%. These results show that the FM Test allows early detection of a prethrombotic state in the development of postoperative DVT.