Rivaroxaban or Placebo for Extended Antithrombotic Prophylaxis After Laparoscopic Surgery for Colorectal Cancer.

Inclusion Criteria: * Objective diagnosis of colorectal cancer; * Elective laparoscopic surgery for colorectal cancer * Whatever the stage of cancer * Antithrombotic prophylaxis with LMWH administered for 7±2 days after surgery Exclusion Criteria: * Age \< 18 years * Surgery for non-cancer disease * Duration of surgery \< 45 min * Conversion to open surgery * 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.