Analysis of the Vascular Interrelationships Among the First Jejunal Vein, the Superior Mesenteric Artery, and the Middle Colic Artery.

BACKGROUND: The technical difficulty of laparoscopic surgery for transverse colon cancer is partly due to the vascular variability around the middle colic vessels. Although individual variations in the arteries or veins in this area were previously investigated, the vascular interrelationships between these vessels remain unknown. This study was designed to investigate the vascular interrelationships between the arteries and veins around the middle colic vessels and to provide practically useful classifications.

METHODS: This study included 105 consecutive patients who underwent colorectal surgery for colorectal tumors in our institution in 2016. Patients with a history of colectomy were excluded. Vascular anatomical classifications were analyzed by evaluating thin-slice images of preoperative contrast-enhanced computed tomography.

RESULTS: Vascular anatomical patterns were classified according to whether the first jejunal vein ran behind (type A) or in front (type B) of the superior mesenteric artery. Type B was subclassified into two subtypes, depending on whether the middle colic artery originated cephalad (type B1) or caudad (type B2) to the first jejunal vein. We identified 83 (79.0%) cases of type A, 11 (10.5%) of type B1, and 11 (10.5%) of type B2. In 17 cases, the middle colic vein drained into the inferior mesenteric vein, and all of these were type A (P = 0.0202). Furthermore, in eight cases, the middle colic vein drained into the first jejunal vein, and all of these were type B (P < 0.0001).

CONCLUSIONS: This study elucidated the vascular interrelationships around the middle colic vessels. Our findings provided important knowledge for laparoscopic surgery in treating transverse colon cancer.