Anatomical variations of the arterial supply in the colonic splenic flexure: A 3D angio-CT study and its surgical implications

To evaluate the vascular anatomy of the colonic splenic flexure focusing on the left colic artery (LCA), the left branch of the middle colic artery (left-MCA), and the accessory middle colic artery (AMCA) and to correlate these findings with the observed variations of the middle colic artery (MCA) and inferior mesenteric artery (IMA). Two hundred three-dimensional CT angiography (3D CTA) exams were reviewed for a targeted study of the vascular anatomy of the left-MCA, the AMCA and the LCA. The presence of the left-MCA, the AMCA, and the LCA was observed in 98.5%, 22%, and 99%, respectively. The participation of each of these vessels in the blood supply of the colonic splenic flexure was 14%, 19.5%, and 82%, respectively. In cases in which the AMCA did not participate in the blood supply of the colonic splenic flexure, there was more significant participation (p < 0.001) of the LCA. The arterial supply in the colonic splenic flexure was type 1, trough LCA in 60% of cases; type 2, through left-MCA in 4%; type 3, through LCA and left-MCA in 10%; type 4, through AMCA in 7.5%; type 5, through LCA and AMCA in 12%; type 6, through other arteries in 6.5%. Preoperative knowledge of the vascular anatomy of the colonic splenic flexure is crucial for the surgical strategy and patient safety regarding vascular ligatures and appropriate lymphadenectomies in the approaches to tumors involving the colonic splenic flexure and rectosigmoid.