Postoperative Changes in the Plasmatic Levels of Tissue-Type Plasminogen Activator and Its Fast-Acting Inhibitor - Relationship to Deep Vein Thrombosis and Influence of Prophylaxis

Abstract

SummaryFibrinogen, euglobulin lysis time (ELT), tissue-type plasminogen activator (t-PA) antigen, plasminogen activator inhibitor activity (PA-inhibitor) and α2-antiplasmin (a2-AP) were measured pre- and postoperatively in 60 patients undergoing total hip replacement. Reduced fibrinolytic activity as assessed by the prolongation of euglobulin lysis time, decrease of t-PA and increase of PA-inhibitor and β2-AP could be demonstrated. These changes did not correlate with the postoperative deep vein thrombosis (DVT) diagnosed with the 125I-fibrinogen test. However, preoperative PA-inhibitor activity was significantly higher in patients with postoperative DVT (p <0.01). The prophylactic treatment with aspirin (20 patients) and with heparin plus dihy-droergotamine (20 patients) induced significant changes in some of those parameters.This study shows that the decrease of t-PA and the increase of PA-inhibitor may contribute to the reduced postoperative fibrinolytic activity after total hip replacement. PA-inhibitor level might be a useful marker in evaluating the risk of developing DVT in patients undergoing total hip replacement.