Right colic artery

The right colic artery (RCA) is a branch of the superior mesenteric artery (SMA) that supplies the ascending colon. It courses within the right mesocolon toward the ascending colon, where it typically bifurcates into ascending and descending branches that anastomose with branches of the middle colic artery superiorly and the ileocolic artery inferiorly, contributing to the marginal artery of Drummond a continuous paracolic arterial arcade running along the mesenteric border of the colon.

Key anatomical characteristics:

• Origin: Classically described as arising independently from the right side of the SMA, though its origin is highly variable. It may also arise from a common trunk with the middle colic artery or the ileocolic artery.

• Territory: Supplies the ascending colon, bridging the vascular territories of the ileocolic artery (which supplies the cecum and proximal ascending colon) and the middle colic artery (which supplies the transverse colon).

• Prevalence: The RCA is the most inconstant of the three major colic branches of the SMA. Meta-analyses report its presence in approximately 60-73% of individuals, with some cadaveric series finding it in as few as 33% of specimens. When present, it shows high variability in its site of origin arising directly from the SMA in only about 1040% of cases, and frequently originating from the right branch of the middle colic artery (up to 36%) or sharing a common trunk with the ileocolic artery.

• Course: When present, the RCA most commonly runs ventral to the superior mesenteric vein (approximately 89% of cases).