Age

18–any

Sex

ALL

Healthy volunteers

Not accepted

age \< 18 years
surgery for non-cancer disease
duration of surgery \< 45 min
other indication for anticoagulant therapy
known cerebral metastases
kidney or liver failure
known hemorrhagic diathesis or high risk for bleeding
history of intracerebral bleeding or neurosurgery within 6 months, history of heparin induced thrombocytopenia
pregnancy or lactation
refusal of informed consent.

ONE WEEK VERSUS FOUR WEEK HEPARIN PROPHYLAXIS AFTER LAPAROSCOPIC SURGERY FOR COLORECTAL CANCER.