Trial Information

Factors Influencing the Impact of Contrast-Enhanced Intraoperative Ultrasound During Liver Surgery for Colorectal Cancer Liver Metastases

Contrast-enhanced intraoperative ultrasound (CE-IOUS) during surgery for colorectal liver
metastases (CLM) is entered in clinical practice. However, its impact seems to decrease with
the improvement of preoperative imaging. Therefore, if CE-IOUS should be selectively or
routinely applied remains unclear: a profile of patients who may benefit of CE-IOUS
application has to be disclosed. The aim of this study is to define reliable criteria for a
selective use of CE-IOUS during surgery for CLM. IOUS is performed using 3-6 MHz convex
probe, and a 7.5-10 MHz micro convex probe. Staging is completed by CE-IOUS using the
standard 3-6 MHz convex probe and the dedicated 1.88-3.76 MHz harmonic frequency probe. In
all patients, 2.4 mL of sulphur-hexafluoride microbubbles (SonoVue®, Bracco, Milan, Italy)
are injected through a peripheral vein by the anesthesiologist. Ultrasound guidance is used
to drive the dissection plane as previously described. Reference standards are histology and
imaging at 6 months after surgery. Univariate and multivariate analyses are performed.
Statistical significance is set at P=0.05.