Contrast-enhanced intraoperative ultrasonography in surgery for liver tumors.

IOUS is the most accurate diagnostic technique for assessing focal liver lesions, but still has some drawbacks. Contrast-enhanced ultrasound examination done intraoperatively (CE-IOUS), using second generation contrast agents (SonoVue, Bracco-Imaging, Milan, Italy), seems able to overcome those aforementioned lacking aspects of IOUS. In cirrhotic patients with hepatocellular carcinoma (HCC), CE-IOUS provides information about tumor vascularity which are useful for nodules differentiation: this should improve the surgical radicality. Furthermore, two different pattern of enhancement are also recognizable at CE-IOUS in those HCC nodules depicted preoperatively: one of them has no similarity with that observed at computed tomography (CT). In patients who undergo surgery for colorectal liver metastases, CE-IOUS seems to improve the sensitivity of IOUS to small, hypoechoic lesions, reducing the risk to down-stage the disease and enhancing the rate of treatment with curative intent. In conclusion, IOUS accuracy is improved by CE-IOUS with an impact on surgical strategy either for primary than for metastatic tumors. Furthermore, a wider experience with vascular enhancement patterns at CE-IOUS could provide new classification for liver lesions.