The role of intraoperative ultrasound for the assessment of the focal liver lesions in patients with colorectal cancer.

Objective: To evaluate the concordance between intraoperative ultrasound (IOUS) and abdominal ultrasound (US) for the characterization of focal liver lesions in patients with colorectal cancer, and to evaluate the way in which IOUS influences the initially established hepatic surgical protocol based on abdominal US only.

Method: In this prospective study 73 patients with colorectal cancer and focal liver lesions found during IOUS were included. Abdominal US and IOUS findings were compared. The initially established hepatic surgical protocol based on abdominal US only was recorded. All patients in whom IOUS influenced this protocol and the way in which this was influenced were recorded.

Results: Of the 73 patients, 41 (56.2%) had focal liver lesions classified as malignant by IOUS. In 26 of the 73 patients (35.6%), there were discordances between abdominal US and IOUS. IOUS influenced the operative protocol in 9 of the 73 patients included in the study (12.3%), and in 8 of the 41 patients with malignant lesions (19.5%). IOUS influenced the operative protocol by cancelling the preoperative hepatic surgery decision by evidencing the additional multiple malignant focal liver lesions, following the classification of some lesions as benign or by demonstrating the non-resectable character of other lesions. IOUS also determined unplanned hepatic resections by detecting resectable malignant lesions undiagnosed by abdominal US, and extended or limited the scheduled hepatic surgery based on abdominal US only.

Conclusions: There were inconsistencies between IOUS and abdominal US, therefore in patients with colorectal cancer IOUS provided additional information about focal liver lesions. IOUS influenced the operative protocol and consequently, unnecessary liver surgery was avoided. Also, IOUS identified malignant resectable liver lesions which were undetected by abdominal US.