The pre-, peri-, and postsurgical activation of coagulation and the thromboembolic risk for different risk groups.

Patients after surgery stand at high risk of developing thromboembolic complications. Nevertheless, there is at present no universal and valid guideline on the duration of heparin prophylaxis. This study aims to assess the thromboembolic risk after the different surgical treatments for different risk groups, based on the activation of the plasmatic coagulation and fibrinolysis system. This is measured by estimating the levels of the fibrin monomers (FM) and fibrin-D-dimers (FD) in plasma during the pre-, peri-, and postsurgical periods in patients from the different clinical risk categories (i. e., posttraumatic or elective hip replacement and osteosynthesis and abdominal surgery: conventional or minimal invasive in malignant and non malignant diseases). During an observation period of 14 days the FM and FD levels were found to be significantly elevated in patients from all risk groups. Underlying malignant diseases lead to an elevation of the procoagulatory risk, whereas age itself does not. Patients who underwent hip surgery seemed to be especially at risk. Even after 14 days or at the date of discharge the FM and FD levels were elevated to maximum showing sustained precoagulatory conditions and increased thromboembolic risk. For these patients the long-term prophylaxis, lasting possibly longer than the average hospitalization period, seems evident. Clinical trials to prove this hypothesis are nevertheless urgently recommended. A corresponding clinical trial that compares long-term against standard heparinization was therefore initiated and is now in progress.