Background: Meticulous assessment of the left liver for patients scheduled for right hepatectomy is essential. Endoscopic ultrasonography (EUS) is frequently used for the locoregional staging or biopsy of pancreatic tumours and has shown some value in the evaluation of the left liver.
Methods: We prospectively enrolled 24 consecutive patients who were scheduled for at least a right hepatectomy and who underwent laparotomy for colorectal liver metastasis (CLMs). The left liver was assessed preoperatively with standard techniques [computed tomography (CT) scan, percutaneous ultrasonography] and EUS. These results were compared with those of intraoperative ultrasonography (IOUS).
Results: The study population consisted of 12 men and 12 women (mean age 64 years, range 47-79 years). Mean body mass index was 26 kg/m(2) (range 20-35 kg/m(2)). Standard preoperative evaluation detected 28 lesions in the left liver; EUS detected just 17 lesions, whereas IOUS detected 30 lesions in the left liver. For the left lobe of the liver (segments II and III), the standard evaluation had sensitivity of 85%, specificity of 64%, positive predictive value (PPV) of 50% and negative predictive value (NPV) of 91%; EUS had sensitivity of 55%, specificity of 86%, PPV of 71% and NPV of 76%; IOUS had sensitivity of 85.2%, specificity of 92%, PPV of 96.6% and NPV of 75%. In terms of the left liver (i.e. segments II, III and IV), the results of EUS were less good than for the left lobe of the liver.
Conclusion: For segments II and III, EUS had higher specificity and positive predictive value than standard evaluation, but only changed our therapeutic strategy in three cases. Even though EUS can provide some valuable information, the technique is not accurate enough to merit systematic performance as part of a standard preoperative evaluation. This study underlines the main role of IOUS in the left liver, with better sensitivity, specificity, and positive predictive value than EUS and standard evaluation.