Intra-operative liver ultrasound--a contribution to colorectal carcinoma staging

Laparoscopic resection of colorectal carcinoma is now a well-established surgical technique with oncology treatment outcome similar to open surgery, yet performing better in some short-term variables. The technique, however, does not allow palpation of intra-abdominal organs and the liver in particular. This prospective study aims to assess the performance of laparoscopic intra-operative ulrasonography of the liver (L-IOUS) and compare its findings with pre-operative staging data.

In total 70 patients, 53 men and 17 women, who were recruited into the study, were indicated for primary laparoscopic resection for colorectal carcinoma, with laparoscopic intra-operative ulrasonographic examination of the liver (L-IOUS) being used during the initial part of the operation. Before surgery, all patients underwent abdominal and pelvic contrast CT examinations. Ultrasonographic examination of the liver was included.

In 14 patients L-IOUS detected a synchronous metastatic lesion of the liver as opposed to only six patients with pre-operative CT-positive findings. Furthermore, CT-positive metastases in three patients were not confirmed by L-IOUS. Several patients were diagnosed with benign lesions not disclosed during pre-operative assessment, e.g. haemangioma in 5 vs 2 patients, focal nodular hyperplasia in 3 vs 1 patient and liver cysts in 7 vs 5 patients.

Results of the presented prospective study substantiate the use of laparoscopic intra-operative ultrasound of the liver (L-IOUS) within the standard staging protocol, as this seems to appropriately supplement the results of the pre-operative staging. In cases of colorectal carcinoma the method allows highly sensitive detection of occult synchronous liver metastases that could finally alter a therapeutic strategy.