Vascular variants in laparoscopic extended right hemicolectomy with central vascular ligation for right colon cancer.

PURPOSE: To evaluate the right colic vascularity, focusing on the confluences of veins.

METHODS: The subjects of this retrospective study were 100 patients who underwent laparoscopic extended right hemicolectomy (Lap-ERHC) between April 2015 and September 2020, at our hospitals. Veins draining into the superior mesenteric vein (SMV) included the ileocecal vein (ICV), the right colic vein (RCV), the middle colic vein (MCV), and the gastrocolic trunk of Henle (GCT). Veins draining into vessels other than the SMV were defined as accessory colic veins (aICV, aRCV or aMCV).

RESULTS: The GCT, aRCV, and aMCV were found in 86, 89, and 15 patients, respectively. In 66 patients with one aRCV, drainage was split as the anterior superior pancreaticoduodenal vein (ASPDV) in 12, the right gastroepiploic vein (RGEV) in 7, and the GCT in 47. In 23 patients with two aRCVs, drainage was split as the ASPDV in 4, the RGEV in 1, the GCT in 11, and the ASPDV and GCT in 7. In 14 patients with one aMCV, drainage was split as the GCT in 8, the splenic vein in 5, and the first jejunal vein (FJV) in 1. One patient had two aMCVs, draining into the GCT and the FJV.

CONCLUSIONS: The findings of our evaluation of vascular anatomy, focusing on confluences of the colic veins, provides useful information for colorectal surgeons.