Outcomes of high versus low ligation of the inferior mesenteric artery with lymph node dissection for distal sigmoid colon or rectal cancer

Purpose We compared the complication rates and oncologic and functional outcomes of high versus low ligation of the inferior mesenteric artery (IMA). Methods We reviewed data retrospectively from 776 patients, divided into high and low IMA ligation groups. Low ligation was performed with lymph node dissection around the IMA root. Postoperative complications and oncologic and functional outcomes were analyzed. Results There were 613 patients in the high ligation group and 163 patients in the low ligation group. Most clinicopathological variables were similar. There were no significant differences in complication rates (25.1% vs. 28.8%; p = 0.336), anastomotic leakage (2.8% vs. 2.5%; p = 1.000), colonic ischemia (2.8% vs. 1.2%; p = 0.393), 5-year overall survival (79.6% vs. 81.3%; p = 0.137) or 5-year relapse-free survival (77.4% vs. 73.3%; p = 0.973) between the groups. In terms of functional outcomes, both techniques were equivalent. The International Prostate Symptom Score and Fecal Incontinence Severity Index were significantly better in the low ligation group 12 months postoperatively than 3 months postoperatively. Conclusions The oncologic and functional outcomes, as well as postoperative complications, after low ligation of the IMA with lymph node dissection are not significantly different from those after high ligation of the IMA.