Table 1 Eligibility Criteria

   • Patients being considered for a potentially curative (R0) right hepatectomy (removal of segments 5,6,7,8), extended right hepatectomy (removal of segments 5,6,7,8, part of segment 4) or right trisegmentectomy (removal of segments 4,5,6,7,8) for colorectal liver metastases

   • Age equal or greater than 18 years

   • Absence of any psychological, familial, sociological or geographical condition potentially hampering compliance with the study protocol, follow-up schedules or from signing informed consent

   • Written informed consent from each patient or the patient's legal guardian prior to entering the study

   • No evidence of active or former concurrent malignant diseases (except non-melanous skin cancer)

Exclusion criteria

   • Any extrahepatic disease, even if this will be resected concomitantly

   • Liver cirrhosis

   • Grossly positive lymph nodes in the hepatoduodenal ligament

   • Positive margins after liver resection (R1) (Patients will be excluded from further follow up, the patient's data however will be recorded).

   • Patients with an intraoperative blood loss of >= 2000 cc will be excluded from the analysis of tumor cell detection in blood samples but will be included in the rest of the analyses.