From the Research
The correct answer is B. Marginal artery. The splenic flexure of the colon is primarily supplied by the marginal artery, which is also known as the marginal artery of Drummond. This vessel runs along the mesenteric border of the colon and forms an important anastomotic network between the superior mesenteric artery (SMA) and inferior mesenteric artery (IMA) systems. At the splenic flexure specifically, the marginal artery creates a critical connection between the middle colic artery (a branch of the SMA) and the left colic artery (a branch of the IMA) 1. This anastomosis at the splenic flexure is particularly important clinically as it can be a watershed area with potentially precarious blood supply, sometimes referred to as the "point of Griffiths." While the middle colic artery contributes to the blood supply of the transverse colon, it is the marginal artery that directly supplies the splenic flexure through this anastomotic connection. Some studies have shown variations in the blood supply to the splenic flexure, including the presence of an accessory middle colic artery (AMCA) 2, but the marginal artery remains the primary supplier of blood to this region. The most recent and highest quality study on this topic, published in 2024, confirms the importance of the marginal artery in supplying the splenic flexure 1. Key points to consider include:
- The marginal artery is the primary supplier of blood to the splenic flexure
- The middle colic artery contributes to the blood supply of the transverse colon, but not directly to the splenic flexure
- Variations in blood supply to the splenic flexure can occur, including the presence of an AMCA
- The marginal artery forms an important anastomotic network between the SMA and IMA systems.