Vascular anatomy for right colon lymphadenectomy.

Since the superior mesenteric artery (SMA) mostly originates on the left side of the superior mesenteric vein (SMV), the ileocolic artery (ICA) and the right colic artery (RCA) cross the SMV. Understanding the three-dimensional relation of these vessels is important for dissecting these arteries to their origin. Hence, we conducted a study of the vascular anatomy of the right colon in 27 cadavers. The RCA was separate from the SMA in eight cases (30%). The RCA passed the SMV either anteriorly (5 cases, 63%) or posteriorly (3 cases, 38%). In seven (88%) of these eight cases, the ICA was posterior to the SMV. The ICA was identified in all 27 cases, and passed the SMV anteriorly in nine cases (33%) and posteriorly in 18 cases (67%). Thus, the ICA and the RCA may pass on either side of the SMV. The surgeon must dissect the arteries with the SMV, being aware of both possibilities.