Intraoperative ultrasonography during planned liver resections remains an important surgical tool

Laparoscopic microwave ablation of human liver tumours using a novel three-dimensional magnetic guidance system

BACKGROUND

Accurate antenna placement is essential for effective microwave ablation (MWA) of lesions. Laparoscopic targeting is made particularly challenging in liver tumours by the needle's trajectory as it passes through the abdominal wall into the liver. Previous optical three-dimensional guidance systems employing infrared technology have been limited by interference with the line of sight during procedures.

OBJECTIVE

The aim of this study was to evaluate a newly developed magnetic guidance system for laparoscopic MWA of liver tumours in a pilot study.

METHODS

Thirteen patients undergoing laparoscopic MWA of liver tumours gave consent to their participation in the study and were enrolled. Lesion targeting was performed using the InnerOptic AIM™ 3-D guidance system to track the real-time position and orientation of the antenna and ultrasound probe.

RESULTS

A total of 45 ablations were performed on 34 lesions. The median number of lesions per patient was two. The mean ± standard deviation lesion diameter was 18.0 ± 9.2 mm and the mean time to target acquisition was 3.5 min. The first-attempt success rate was 93%. There were no intraoperative or immediate postoperative complications. Over an average follow-up of 7.8 months, one patient was noted to have had an incomplete ablation, seven suffered regional recurrences, and five patients remained disease-free.

CONCLUSIONS

The AIM™ guidance system is an effective adjunct for laparoscopic ablation. It facilitates a high degree of accuracy and a good first-attempt success rate, and avoids the line of site interference associated with infrared systems.

Application of contrast-enhanced intraoperative ultrasonography in the decision-making about hepatocellular carcinoma operation

AIM: To evaluate the detection and differentiation ability of contrast-enhanced intraoperative ultrasonography (CE-IOUS) in hepatocellular carcinoma (HCC) operations.

METHODS: Clinical data of 50 HCC patients were retrospective analyzed. The sensitivity, specificity, false negative and false positive rates of contrast enhanced magnetic resonance imaging (CE-MRI), IOUS and CE-IOUS were calculated and compared. Surgical strategy changes due to CE-IOUS were analyzed.

RESULTS: Lesions detected by CE-MRI, IOUS and CE-IOUS were 60, 97 and 85 respectively. The sensitivity, specificity, false negative rate, false positive rate of CE-MRI were 98.2%, 98.6%, 98.6%, 60.0%, respectively; for IOUS were 50.0%, 90.9%, 1.8%, 1.4%, respectively; and for CE-IOUS were 1.4%, 40.0%, 50.0%, 9.1%, respectively. The operation strategy of 9 (9/50, 18.0%) cases was changed according to the results of CE-IOUS.

CONCLUSION: Compared with CE-MRI, CE-IOUS performs better in detection and differentiation of small metastasis and regenerative nodules. It plays an important role in the decision-making of HCC operation.

Contrast-enhanced ultrasound in the biliary system: Potential uses and indications

Conventional ultrasound (US) is the first-line imaging investigation for biliary diseases. However, it is lack of the ability to depict the microcirculation of some lesions which may lead to failure in diagnosis for some biliary diseases. The use of contrast-enhanced US (CEUS) has reached the field of bile duct disease in recent years and promising results have been achieved. In this review, the methodology, image interpretation, enhancement pattern, clinical usefulness, and indications for CEUS in the biliary system are summarized. CEUS may be indicated in the biliary system under the following circumstances: (1) Where there is a need to make a characterization of intrahepatic cholangiocarcinoma (ICC); (2) For differentiation diagnosis between ICC and other tumors (i.e. hepatocellular carcinoma or liver metastasis) or infectious diseases; (3) For differentiation diagnosis between biliary cystadenoma and biliary cystadenocarcinoma; (4) To detect malignant change in Caroli’s disease; (5) To depict the extent of Klatskin’s tumor with greater clarity; (6) To make a distinction between gallbladder cholesterol polyp, adenoma and polypoid cancer; (7) To make a distinction between chronic cholecystitis with thickened wall and gallbladder cancer; (8) For differentiation diagnosis between motionless sludge and gallbladder cancer; (9) For differentiation diagnosis between common bile duct cancer and sludge or stone without acoustic shadowing; and (10) In patients who are suspected of having a drop of their percutaneous transhepatic cholangiodrainage tube, US contrast agent can be administered to through the tube detect the site of the tube.

Value of contrast-enhanced intraoperative ultrasound for cirrhotic patients with hepatocellular carcinoma: A report of 20 cases

AIM: To assess the clinical value of contrast-enhanced intraoperative ultrasound (CE-IOUS) as a novel tool in partial hepatectomy for cirrhotic patients with hepatocellular carcinoma (HCC).

METHODS: From January 2007 to September 2007, a total of 20 consecutive cirrhotic patients with HCC scheduled to undergo partial hepatectomy were studied. Preoperative contrast enhanced computer tomography (CT) and/or magnetic resonance (MR) scans were performed within 1-2 wk before operation. Intraoperative ultrasound (IOUS) and CE-IOUS were carried out after mobilization of the liver. Lesions on precontrast and postcontrast scans were counted and mapped. CE-IOUS was performed with intravenous injection of ultrasound contrast agents SonoVue (Bracco Imaging, Milan, Italy). Arterial, portal and late phases of contrast enhancement were recorded and analyzed. Nodules showing arterial phase hyper-enhancing and/or hypo-enhancing in late parenchymal phase were considered malignant and removed surgically. Ultrasound-guided biopsy and ethanol ablation would be an option if the nodule could not be removed surgically. Newly detected nodules on IOUS showing iso-enhancement in both arterial and late phases were considered benign. These nodules were either removed surgically if they were close to the main lesion or followed by examinations of alpha-fetoprotein (AFP) level and ultrasound and/or CT/MR every 3 mo.

RESULTS: IOUS found 41 nodules in total, among which 17 (41.46%) were newly detected compared to preoperative imaging. Thirty-three nodules were diagnosed malignant by CE-IOUS, including one missed by IOUS. The sensitivity and specificity of CE-IOUS on detecting HCC nodules are 100% (33/33 and 100% (9/9), respectively. Nine nodules were considered benign by CE-IOUS, four was confirmed at histology and five by follow-up. CE-IOUS changed the surgical strategy in 35% (7/20) of patients and avoid unnecessary intervention in 30% (6/20) of patients.

CONCLUSION: CE-IOUS is a useful means to charac-terize the nodules detected by IOUS in cirrhotic liver, to find isoechoic HCC nodules which can not be shown on IOUS and to improve the accuracy of conventional IOUS, thus it can be used as an essential tool in the surgical treatment of cirrhotic patients with HCC.