Third pa of duodenum is crossed by
The third pa, or horizontal pa or inferior pa of the duodenum begins at the inferior duodenal flexure and passes transversely to the left, passing in front of the inferior vena cava, abdominal aoa and the veebral column. The superior mesenteric aery and vein are anterior to the third pa of duodenum. Ref - BDC 6e vol2 pg262
Poal vein
Hepatic aery
Bile duct
Superior mesenteric aery
Abdomen and pelvis