INDICATION FOR USING HIGH LIGATION OF THE INFERIOR MESENTERIC-ARTERY IN RECTAL-CANCER SURGERY - EXAMINATION OF NODAL METASTASES BY THE CLEARING METHOD

PURPOSE: In surgery for rectal cancer, it is unclear whether the infer ior mesenteric artery should be ligated at a high or low position. The study contained herein was undertaken to clarify the indications for high ligation of the inferior mesenteric artery. METHODS: Subjects inc luded 198 patients with rectal cancer who underwent resection with hig h ligation of the inferior mesenteric artery. Nodal metastases were ex amined by the clearing method. RESULTS: The incidence of metastases to the lymph nodes surrounding the origin of the inferior mesenteric art ery (root nodes) was 8.6 percent. Inferior mesenteric artery root noda l metastases occurred more frequently with pT3 and pT4 cancer. The fiv e-year survival rate in patients with inferior mesenteric artery root nodal metastases was 38.5 percent; this rate was significantly lower t han in those without inferior mesenteric artery root nodal metastases (73.4 percent). CONCLUSIONS: Although the five-year survival rate in p atients with inferior mesenteric artery root nodal metastases was lowe r than in those without metastases, inferior mesenteric artery root no dal dissection should be performed after high ligation of the inferior mesenteric artery for patients with pT3 and pT4 cancers.