The purpose of this study is to investigate the natural kinetics of D-dimers that occur after abdominal surgery.

Venous thromboembolism (VTE) is a potentially fatal disease with an estimated incidence of 0.1%. One third of the VTE occur as pulmonal embolism with a mortality up to 25% (White RH. Circulation 107:2003)

Serum d-dimer levels are used as sensitive marker for the diagnosis of VTE (Kelly J et al. Arch Intern Med, 162: 2002). Because of its sensitivity, the determination of serum D-dimer levels is an accepted method to exclude VTE in the outpatient setting meaning that VTE may be excluded in case of normal D-dimer levels (Kelly J. Lancet 359: 2002). The specificity of the D-dimer testing, however, is low. This is true especially in the postoperative phase. The interpretation of elevated D-dimer levels in surgical patients remains elusive.

The natural kinetics of D-dimers after surgery is not known. The question to what extent D-dimer levels rise after surgery and how long it may take D-dimer levels to return to normal after surgery is not yet determined. This information is needed to be able to use D-dimer testing for VTE diagnosis in surgical patients.

In this study, D-dimer levels are measured in surgical patients immediately before (day 0) and repeatedly after surgery. D-dimer level measurement will be stopped after D-dimer levels returned to normal.

Inclusion Criteria:

• patients undergoing elective surgery

Exclusion Criteria:

• age < 18 years
• patients not speaking german
• patients involved in another study
• pregnancy
• concommitant inflammatory disease
• patients with oral anticoagulation
• patients having received fresh frozen plasma