BackgroundTo perform a safe and precise laparoscopic surgery for the splenic flexure cancer, it is important for surgeons to gain a preoperative understanding of the running of the feeding artery of the splenic flexure. We evaluated the blood supply to the splenic flexure by using preoperative three-dimensional computed tomography (3D-CT).MethodWe retrospectively analyzed a total of 88 patients with colorectal cancer who underwent preoperative 3D-CT at our institutions between April 2016 and June 2017.ResultsThe arterial blood supply to the splenic flexure was divided into four patterns as follows: type 1, the left branch of the middle colic artery (MCA) with common trunk and the left colic artery (LCA) (n = 48, 54.5%); type 2, the left branch of the MCA with independent origin and the LCA (n = 8, 9.1%); type3, the accessory-MCA (A-MCA) and the LCA (n = 27, 30.7%); and type4, the LCA alone (n = 5, 5.7%). The MCA had the common trunk of the right and left branches in the majority of cases (85.2%). The right and left branches of the MCA arose separately from the superior mesenteric artery (SMA) in 8 of 88 patients (9.1%).ConclusionsThe arterial patterns of the splenic flexure were classified into four patterns by using preoperative 3D-CT. The A-MCA existed in 30% of the patients in this study. These information should be helpful to perform the optimal surgery for the splenic flexure cancer.