Perihepatic Lymph Node Assessment in Patients Undergoing Partial Hepatectomy for Malignancy

Resection remains the most effective therapy for selected patients with primary and secondary hepatic malignancy. In general, metastatic disease to extrahepatic sites is associated with poor survival and has been a contraindication to hepatic resection. In particular, regional metastases to perihepatic lymph nodes are a significant negative prognostic factor for both primary1–3 and secondary hepatic malignancies.4–8 On the other hand, selected patients with limited regional nodal disease may benefit from resection.7 Furthermore, as improvements in systemic chemotherapy continue to evolve, particularly for metastatic colorectal cancer, regional lymph node status may not necessarily be used to determine resectability but rather to select patients for optimal postresection chemotherapeutic therapies.9 The reported rate of perihepatic lymph node positivity in patients undergoing hepatic resection varies by histology,10 ranging from 10.6%7 to 28%5 in patients with hepatic colorectal metastases, 27%3 to 45%11 for intrahepatic cholangiocarcinoma and approximately 5% for hepatocellular carcinoma.12 Many of these studies include patients with obvious nodal involvement. Clearly, some patients have microscopic disease that is beyond detection by conventional radiographic imaging or even direct palpation. As a result, some authors have advocated routine lymph node sampling or lymphadenectomy for all patients undergoing hepatic resection.10,13 Although it has been suggested that occult metastasis to perihepatic lymph nodes is relatively common in patients with malignant liver disease, the incidence of truly occult disease is difficult to determine. Furthermore, there is currently no consensus regarding the optimal method of preoperative or intraoperative assessment of perihepatic lymph nodes in patients undergoing resection for hepatic malignancy. The present study investigates and compares the relative value of preoperative imaging (CT and PET) and intraoperative assessment of perihepatic lymph nodes, and particularly aims to determine the incidence of metastatic involvement that is clinically and radiographically undetectable.