Objective: To observe the effect of injecting activated carbon ultramicroparticles around the gastric tumor before or during operation on staining lymph nodes and guiding the lymphadenectomy of gastric cancer.
Methods: Forty-three cases of gastric cancer received activated carbon (AC) ultramicroparticles around the tumor by submucosal endoscopic injection 1 approximately 6 days before the operation and/or intraoperative subserosal injection (AC group), whereas 82 cases of gastric cancer without the injection were used as control group. The number of dissected lymph nodes, number of black-stained lymph nodes and its relation to the injection time, metastasis of lymph nodes, and the side effect of the procedure were analyzed.
Results: The average numbers of resected lymph nodes were 34 +/- 13 in the AC group, significantly higher than that in the control group (16 +/- 9, P < 0.05). The dissected N(2) lymph nodes in the AC group was 25 +/- 9, significantly higher than that in the control group (8 +/- 4, P < 0.05). The total ratio of black-stained lymph node was 60.3% in general, 71.3% for the N1 lymph nodes and 56.3% for the N(2) lymph nodes in the AC group. Satisfactory effect of black staining of lymph nodes could be seen 2 days after local gastric tissue injection of activated carbon ultramicroparticles. The metastasis rate was 67.4% in the AC group, not significantly different from that in the control group (63.4%, P > 0.05). In the patients of AC group the metastasis rate of black-stained lymph node was 26.8%, significantly higher than that of the unstained lymph nodes (3.3%) and higher than that of the control group (18.4%). No serious side effect happened after the activated carbon ultramicroparticles injection in local gastric tissue.
Conclusion: Local injection of activated carbon ultramicroparticles around the tumor is an effective, easy and safe procedure to guide gastric cancer lymphadenectomy.