A study of the area of paraaortic lymph nodes dissection in gastric cancer based on lymphatic flow of the stomach using radioactive isotope

In gastric cancer patients, I subdivided paraaortic lymph nodes (No.16) into 4 zones. Using RI lymphography I analyzed the lymphatic flow from the cardiac and pyloric region to the No.16. Also, based on these results as well as studies of clinical lymph node metastasis, I elucidate the rational No.16 area in extended lymph node dissection. The lymphatic flows to the No.16 by RI lymphography showed the following routes. The route from the cardiac region was: (1) along the left gastric artery heading towards lymph node around the celiac artery and into the left/right No.16; (2) along the posterior gastric artery and splenic artery from lymph node around the splenic artery directly to the left No.16; (3) along the inferior phrenic artery from left cardiac lymph node and lymph node at the splenic hilus directly to the left upper No.16. The route from the pyloric region was: (1) along the common hepatic artery heading towards lymph node around the celiac artery to the left/right No.16; (2) from infrapyloric lymph node along the gastrocolic trunc flowing to lymph node at the root of the mesenterium and No.16. In upper gastric cancer, there was a high rate of metastasis to lymph node along the lesser curvature and right cardial lymph node, and lymph node along the left gastric artery and splenic artery. There were 3 cases in which metastasis was positive only to cardial lymph node and upper left No.16. In lower gastric cancer, there was a high rate of metastasis to infrapyloric lymph node, lymph node along the lesser curvature, lymph node along the left gastric artery and the common hepatic artery. In all cases which metastasized in group 4, the No.16 metastasis rate was significantly higher in the upper left No.16, being 84.8%. Given the above, the area of paraaortic lymph node dissection in extended lymph node dissection, irrespective of whether it is upper or lower gastric cancer, must be done in the 4 zones, and especially, the upper left No.16 is important. (author)