Is intraoperative ultrasound still useful for the detection of colorectal cancer liver metastases?

BackgroundDebate on the optimal mode of preoperative imaging in the management of colorectal liver metastases (CRLM) is ongoing and, despite its longstanding use, the precise role of intraoperative ultrasonography (IOUS) is not well established. This study evaluates the impact of IOUS in the era of high-quality, cross-sectional imaging techniques.MethodsAll patients who underwent liver resection for CRLM in a tertiary care referral centre from January 2006 to December 2013 were included. All patients were submitted to computed tomography (CT) and/or liver magnetic resonance imaging (MRI) before surgery. Intraoperative US was performed mainly to detect previously non-diagnosed tumours that would change the surgical strategy.ResultsA total of 225 liver resections were performed. Liver MRI and CT scans were available for 202 patients (89.8%) and 225 patients (100%), respectively. Radiological reports recorded 632 liver tumours in 219 patients (i.e. 2.9 lesions per patient). The median time between preoperative liver MRI and surgical resection was 36 days. Intraoperative inspection, palpation and US found 20 additional lesions in 18 patients (8.0%), in three of whom lesions were diagnosed only on IOUS (1.4%). Overall, only 12 of the 20 lesions were malignant.ConclusionsAlthough CT and liver MRI are commonly used, IOUS alone allows the discovery of a few additional lesions that result in a change of surgical strategy in 1.4% of cases.