A strange case of superior mesenteric venous collar around the superior mesenteric artery.

During our dissection classes, we saw a venous collar formed around the superior mesenteric artery (SMA) by the jejunal tributaries of superior mesenteric vein in an adult male cadaver. The jejunal tributaries united themselves to form two common jejunal veins. Upper common jejunal vein crossed superficial to SMA and opened into the SMV in front of the uncinate process of pancreas. The inferior common jejunal vein crossed behind the SMA from left to right and opened into the SMV, 4 cm below this level. A communicating vein connected the two common jejunal veins with each other.