INCIDENCE AND PREVENTION OF DEEP VENOUS THROMBOSIS OCCURRING LATE AFTER GENERAL-SURGERY - RANDOMIZED CONTROLLED-STUDY OF PROLONGED THROMBOPROPHYLAXIS

Objective: To study the incidence of late deep venous thrombosis (DVT) , and to evaluate a regimen of prolonged thromboprophylaxis after gene ral surgery. Design: Randomised, controlled, open trial, with blinded evaluation. Setting. University hospital, Denmark. Subjects: 176 conse cutive patients undergoing major elective abdominal or non-cardiac tho racic operations, of whom 118 were eligible for evaluation. Interventi ons: Thromboprophylaxis with a low-molecular-weight heparin, tinzapari n, given for four weeks (n = 58), compared with one week (control grou p, n = 60). Main outcome measures: Presence of DVT established by bila teral venography four weeks after the operation. Results: The incidenc e of late DVT in the control group was 6/60 (10%, 95% confidence inter val (CI) 4% to 21%). In the prophylaxis group it was 3/58 (5.2%, 95% C I 1% to 14%) (p = 0.49). Conclusion: Prolonged thromboprophylaxis had no significant effect on the incidence of DVT occurring late after gen eral surgery.