Prospective randomized evaluation of preoperative endoscopic vital staining using CH-40 for lymph node dissection in gastric cancer

Background: CH-40 is a suspension of activated carbon particles that was developed in Japan to carry anticancer drugs to regional nodes and peritoneal seedings of gastric cancer. Methods: Forty-five consecutive patients who had surgical resection and D-2 lymph node dissection for gastric cancer over a 2-year period were randomly assigned to preoperative endoscopic submucosal injection of CH-40 (group A) or no staining (group B). A total of 21 patients in group A and 24 in group B were available for analysis. Results: The number of resected nodes per patient was significantly higher (t = 6.06; 40 df; P < .0001) in group A (mean +/- S.E. = 35.3 +/- 1.24) than in group B (mean +/- S.E. = 25.5 +/- 1.02). The rate of metastatic nodes resected was significantly higher (chi(2) = 6.903; 1 df; P = .009) in stained (22.5%) than in non-stained (14.7%) nodes of group A and also (chi(2) = 6.906; 1 df; P = .009) in stained nodes of group A than in group B (15.8%). Conclusions: Preoperative endoscopic vital staining with CH-40 proved to be rapid, safe, and effective in all cases in this series. Its use allowed surgeons to resect a higher number of lymph nodes, and to identify and examine more metastatic nodes. It also permitted identification of nodal micrometastases on routine histopathologic examination.