FIBRINOLYTIC PARAMETERS IN PATIENTS UNDERGOING TOTAL HIP-REPLACEMENT - RELATIONSHIP WITH THE DEVELOPMENT OF ASYMPTOMATIC DEEP-VEIN THROMBOSIS AND DIAGNOSTIC USEFULNESS OF VENOUS OCCLUSION

Background and Objective. It has been suggested that impaired fibrinol ytic activity contributes to deep vein thrombosis in orthopedic surger y. Studying the fibrinolytic system following venous occlusion has bee n proposed as a good method of detecting the risk of this postoperativ e complication. The objective of this work was to verify whether venou s occlusion represents a reliable method of detecting an impaired fibr inolytic response after total hip replacement. Methods. Thirty-two con secutive patients undergoing total hip replacement were studied. Citra ted blood samples were taken from each patient the day before surgery and on postoperative days 1, 3, and 7, before and after venous occlusi on, in order to evaluate plasma levels of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI-1); All patients unde rwent bilateral phlebography 10 days after surgery. Results. Seven out of 32 patients (21.9%) developed deep venous thrombosis (DVT) accordi ng to the venographic test. After surgery, an increase in t-PA antigen levels was detected both in patients who developed DVT and in those w ho did not, with a significant increase on the first and seventh days after surgery only in the non-DVT group. After 10-min venous occlusion , t-PA antigen levels increased at all postoperative recordings in bot h groups of patients, but most significantly on days 1 and 7 after sur gery. PAI-1 antigen plasma levels, when measured before venous occlusi on, increased only in non-DVT patients on the seventh postoperative da y. After venous occlusion, a difference was found between the two grou ps only postoperatively on day 7 with regard to PAI-1 levels. Interpre tation and Conclusions. According to our results, no impaired fibrinol ytic response was found in DVT patients. In addition, venous stasis se ems to give no further information with respect to basal values in the early detection of postoperative thromboembolic complications in orth opedic patients. (C) 1997, Ferrata Storti Foundation.