Venous Anatomy of the Right Colon

Abstract

PURPOSE: This study was designed to describe the precise venous anatomy of the right colon, which is especially important for laparoscopic right hemicolectomy. METHODS: Fifty-eight adult cadavers were dissected to define the three major venous tributaries of the right colon: the ileocolic vein, right colic vein, and middle colic vein. Two or three middle colic veins were often present, and the biggest one was designated as the main middle colic vein. The middle colic vein and the right colic vein occasionally formed a common trunk with the right gastroepiploic vein and/or the pancreaticoduodenal vein. This common trunk was defined as the gastrocolic trunk. RESULTS: All 58 cadavers had a single ileocolic vein. All of the ileocolic veins drained into the superior mesenteric vein. The right colic vein was absent in 56.9 percent (33/58), and the other 43.1 percent had a single right colic vein. The right colic vein joined the superior mesenteric vein directly in 56 percent (14/25) and the gastrocolic trunk in 44 percent (11/25). The middle colic vein was the most variable. A single middle colic vein was present in 37.9 percent (22/58), 2 middle colic veins were present in 50 percent (29/58), and 3 middle colic veins were present in 12.1 percent (7/58). The main middle colic vein drained into the superior mesenteric vein directly in 84.5 percent (49/58), whereas 12.1 percent (7/58) drained into the gastrocolic trunk. In two cadavers, there was anomalous drainage of the main middle colic vein to the splenic vein and the inferior mesenteric vein. Forty-three accessory middle colic veins were present in total. These drained into the superior mesenteric vein in 17 cadavers and into the gastrocolic trunk in 23. The gastrocolic trunk was present in 69 percent (40/58), being formed with the right colic vein in 27.5 percent (11/40; 1 was together with an accessory middle colic vein) and with the middle colic vein in 75 percent (30/40; 7 with the main middle colic vein, 23 with the accessory middle colic vein). CONCLUSION: Venous anatomy of the right colon is highly variable. It is especially important to recognize the lack of direct drainage of the right colic vein to the superior mesenteric vein and the high frequency of the presence of plural middle colic veins and the gastrocolic trunk.