ObjectivesThe objective of this study is to analyze the main patterns of branching of the inferior mesenteric artery (IMA) and to determine if your knowledge changes the surgical strategy in the colorectal cancer.MethodsThis retrospective study included 63 patients with cancer of the sigmoid or rectum. We assessed the patterns of IMA in 3 subtypes: type A (independent left colic artery [LCA]), type B (LCA and sigmoid artery arising in a common trunk) and type C (LCA, sigmoid artery, and superior rectal artery with a common origin). Colorectal surgeons evaluated how the vascular map changed the type of IMA ligation.ResultsInferior mesenteric artery branching was classified as type A in 55.6% patients, type B in 23.8%, and type C in 20.6%. Knowledge of the vascular map changed the type of ligation from high to low in 20 of the 50 patients who were candidates for surgery. The change was possible in tumors located in the sigmoid colon and the rectosigmoid junction with the type A or B branching.ConclusionsPreoperative Multidetector Computed Tomography angiography can define the pattern of IMA branching. Based on this information, a low ligation can be performed in tumors located in sigmoid colon and rectosigmoid junction with IMA branching types A and B.