The role of variant anatomy of the inferior mesenteric artery in segmental colon resections with lymphodissection in patients with colorectal cancer

Abstract

During laparoscopic surgery for colorectal cancer, vascular structures may be incorrectly identified and damaged due to ignorance of the variant anatomy of the inferior mesenteric artery (IMA), lack of tactile sensations, narrowed field of vision, which leads to complications such as massive bleeding and intestinal ischemia. Therefore, the preoperative study of the variant anatomy of the IMA is of paramount importance. Knowing the variant anatomy of the vessels before surgery, you can make an operation plan in advance, which will ensure fast and safe vascular ligation at the required level and lymph node dissection. Aim: To develop a classification of IMA variability for practical use in operations for colorectal cancer. Material and methods: From February 2013 to March 2022, 214 computed tomograms (CT) of abdominal organs with intravenous contrast were analyzed. We studied the variant anatomy of the IMA. Results: We proposed the classification of structure of the IMA and its branches. This is especially important when the safe lymph node dissection along the IMA is necessary. I type — several colonic branches derivate from the IMA by independent trunks (54,2 %); II type — all colon branches derivate from the IMA in one point like a “goose paw” (25,2 %); III type — one colon branch departs from the IMA by a single trunk; then it divides into colonic branches (20,6 %). The frequency of coincidence of intraoperative data with preoperative CT data was 95.8 %. The sensitivity of the method is 95.8 %, the specificity of the method is 100%. Conclusion: CT with 3D vascular reconstruction allows the surgeon to perform extended lymph node dissection in colorectal cancer with minimal risk of complications.