Association between plasma levels of tissue plasminogen activator and postoperative deep vein thrombosis--influence of prophylaxis with a low molecular weight heparin. The Venous Thrombosis Group.

In a prospective, randomized controlled study, tissue plasminogen activator (t-PA) and tissue plasminogen activator antigen (t-PA:ag) were measured pre- and postoperatively in 40 consecutive patients undergoing total hip replacement. Patients received either a subcutaneous injection of low molecular weight heparin or placebo once daily. Deep vein thrombosis was diagnosed by bilateral phlebography. Patients who developed postoperative thromboembolic complications had significantly lower preoperative t-PA activity levels than patients who did not develop such complications. No difference was observed between the two groups with respect to t-PA:ag. Thromboprophylaxis with low molecular weight heparin did not cause any significant changes in t-PA activity and t-PA:ag. This study in high risk patients indicates that impaired fibrinolysis may be associated with development of thromboembolic complications after operation.

Subcutaneous treatment of deep venous thrombosis with low molecular weight heparin. A dose finding study with LMWH-Novo.

Treatment of deep venous thrombosis with low molecular weight heparin (LMWH-Novo, Logiparin) was carried out with two different doses of Logiparin, 75 XaI U/kg b.w. twice daily and 150 XaI U/kg b.w. once daily subcutaneously for 5 days. Simultaneously warfarin was given from the first day of heparin treatment. Mean age of the twenty patients was 65 years and one third was females. No serious side effects, hematomas, pulmonary emboli or signs of recurrent thrombosis occurred during treatment with either dose regime. Venografic assessment with Marder scoring one week after initiation of Logiparin treatment showed a slight not significant improvement apparent in 40% of the patients. The activities of F-IIaI and F-XaI in the blood plasma were found to increase after injection of Logiparin. These two parameters seem to be the most suitable for monitoring the effect during treatment. For future studies on the therapeutic effect of Logiparin in deep venous thrombosis a single dose of 150 to 200 F-XaI activity per 24 hours seems to be most suitable.

Plasma cross-linked fibrin degradation products fraction D in patients undergoing elective abdominal surgery.

In 18 patients undergoing major abdominal surgery we measured the plasma D-dimer concentration (EIA d-dimer kit) preoperatively, postoperatively, and on postoperative day 1, 3, 4, 5, and 6. The patients received thromboembolic prophylaxis with low-molecular weight heparin. All patients were screened with the 125I-fibrinogen uptake test. Preoperatively, the median plasma D-dimer concentration was 500 ng/ml (200-3200 ng/ml) rising to 1800 ng/ml (500-4600 ng/ml) (p less than 0.05) immediately postoperatively. The plasma D-dimer level increased further during the following days to a maximum of 4800 ng/ml (1600-8600 ng/ml) on the 6th postoperative day (p less than 0.01). One patient developed deep-venous thrombosis. The plasma D-dimer concentration of this patients was within the range of the other patients. In conclusion, the EIA D-dimer test does not seem to be a potential screening procedure for postoperative thrombosis.