The rationale for thrombophrophylaxis is well known. Without prophylaxis the incidence of objectivlely confirmed, hospital-acquired deep venous thrombosis is approximately 10% to 40% among medical or general surgical patients. In urology the prevalence is 15-40%. The Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy1 recommend against specific prophylaxis in patients undergoing transurethral procedures. Our study is the first double-blind, placebo-controlled study with Dalteparine as thrombophrophylaxis in transurethral surgery. The aim of the study is to proof that thrombophrophylaxis causes not more complications in transurethral surgery than without.

The aim of our study is to proof that transurethral surgery under thrombophylaxis with dalteparine is safe. The study design is double-blind placebo controlled.

Inclusion Criteria:

• transurethral surgery

Exclusion Criteria:

• oral anticoagulation