Intraoperative ultrasound in colorectal cancer patients undergoing apparently curative surgery: correlation with two year follow-up.

Conventional ultrasound (US) and computerized tomography (CT) are well recognized to be limited in the detection of small liver metastases. In this study, we assessed the use of intraoperative ultrasound (IOUS) in the detection of 'occult' liver metastases in colorectal cancer patients undergoing apparently curative surgery of the primary colonic carcinoma. Ninety three colorectal cancer patients undergoing apparently curative surgery on the basis of preoperative US, CT and laparotomy were studied. All patients underwent IOUS examination of the liver. After two year follow-up, 27 of these 93 patients developed overt liver metastases and of these 27, only five had been detected by IOUS examinations at the time of laparotomy. The results suggest that IOUS is relatively insensitive in the detection of occult colorectal liver metastases. Its routine use as a screening tool during primary surgery is therefore not recommended.