Laparoscopic lymphatic mapping and sentinel lymph node detection in colon cancer: technical aspects and preliminary results

BACKGROUND: The utility of lymph node mapping to improve staging in colon canceris under evaluation. Laparoscopic colectomy for colon cancer has been validatedin multicentric trials. This study assessed the feasibility of lymph nodemapping in laparoscopic colectomy for colon cancer. METHODS: From March 2004 toDecember 2005, 22 patients were studied. Before resection, 2 to 3 ml of PatentBlue V dye was injected subserosally around the tumor. Colored lymph nodes weremarked as sentinel nodes (SNs) with metal clips, and laparoscopic colectomy withlymphadenectomy was completed as normal. In SNs, multiple 4-mum slices at 50-mumintervals were stained with hematoxylin and eosin and examined. Anticytokeratinantibody immunostaining was applied in doubtful cases. Other lymph nodes wereexamined with multiple slices at 100- to 500-mum intervals by standard methods.RESULTS: The SN detection rate was 100%, although ex vivo lymph node mapping wasnecessary for an obese patient. Five patients (22.7%) were SN positive. Therewas one false-negative SN (16.7%). In two cases (9.1%) with aberrant lymphaticdrainage, lymphadenectomy was extended. The SN reflected the status of theregional lymph nodes in 21 patients (95.4%). Accuracy was 95.4%, and negativepredictive value was 94.1%. CONCLUSIONS: Laparoscopic lymphatic mapping and SNremoval is feasible in laparoscopic colectomy for colon cancer. Although thefalse-negative rate was high (16.7%), the overall results are promising andjustify prospective studies to determine the real accuracy and false-negativerate for the technique.