Analysis of Regional Lymph Node Metastases from Rectal Carcinoma by the Clearing Method: Justification of the Use of Sigmoid Colon in J-Pouch Construction after Low Anterior Resection

摘要

It has been reported that functional outcome following low anterior resection of rectal cancer is improved by construction of a colonic J-pouch compared with straight anastomosis. Hence, we tried to justify use of the sigmoid colon in the construction of a J-pouch by the analysis of regional lymph node metastases. A total of 198 patients underwent resection for rectal cancer. Node metastases were examined by the clearing method. According to Japanese General Rules, nodes were classified into the perirectal nodes (PR-N), pericolic nodes (PC-N), central intermediate nodes (C-IM-N), central main nodes (C-M-N). Metastatic rate (number of patients with node metastases/ total number of patients) of PR-N was 56.6%. Metastatic rate of C-IM-N was 19.2% and that of C-M-N was 8.6%. Metastatic rate of PC-N was only 1.0%. In low anterior resection, high ligation of the inferior mesenteric artery and dissection of C-M-N, C-IM-N and PR-N are necessary. Resection of sigmoid colon is not required, and therefore, a J-pouch can be constructed using the sigmoid colon.