Neither Preoperative Computed Tomography nor Intra-Operative Examination can Predict Metastatic Lymph Node in the Hepatic Pedicle in Patients with Colorectal Liver Metastasis

In patients operated on for colorectal liver metastasis (CRLM), metastatic lymph node (LN) of the hepatic pedicle is a major prognostic factor. Efficiency of preoperative computed tomography (CT) and intraoperative examination for the diagnosis of metastatic LN of hepatic pedicle is prospectively evaluated. From January 2008 to June 2010, 76 patients underwent liver resection for CRLM, with systematic LN pedicle dissection. Preoperative CT scan evaluated prospectively location, size, and aspect of LN, whereas the surgeon assessed size and consistency of LN Results of CT and intraoperative findings were compared with pathologic findings to determine sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV). A total of 241 nodes were analyzed (3.2 +/- A 2.1 LN per patient). Systematic LN dissection increased the operative time by a mean of 20 +/- A 12.5 min, without any specific morbidity or mortality related to the LN clearance. Metastatic LN in the hepatic pedicle was observed in 15 (20%) patients and were unrelated to the number, size, and location of CRLM. NPV and PPV of the preoperative CT scan was 85 and 56%, respectively. Intraoperative evaluation of LN had a high NPV of 91% with a low PPV of 43%. Even with the combination of CT and intraoperative evaluation, 27% of the patients with a pathological metastatic LN were not suspected. Because neither the preoperative CT nor the surgical evaluation accurately predicts metastatic LN in the hepatic pedicle, accurate oncological staging require a systematic pedicular LN clearance during liver resection for CRLM.