The pancreas lies transversely in the retroperitoneum, at the L1–L2 vertebral level, between the duodenum and the hilum of the spleen.

The head of the pancreas lies over the inferior vena cava (IVC), right renal hilum, and the left renal vein at its junction with the IVC.

The uncinate process extends to the left and wraps from around the superior mesenteric vessels. It is in close proximity to the inferior pancreaticoduodenal artery.

The neck of the pancreas lies over the superior mesenteric vessels and the proximal portal vein. The space between the neck and the superior mesenteric vessels is avascular and allows blunt dissection without bleeding. The area to either side of the midline is vascular and should be avoided.

The body of the pancreas lies over the suprarenal aorta and the left renal vessels. It is intimately related to the splenic artery and vein.

The major pancreatic duct (Wirsung) traverses the entire length of the pancreas and drains into the ampulla of Vater, approximately 8 cm below the pylorus. The lesser duct of Santorini branches off the superior aspect of the major duct, at the level of the neck of the pancreas, and drains separately into the duodenum, approximately 2–3 cm proximal to the ampulla of Vater.

The pancreas receives its blood supply from both the celiac artery and the superior mesenteric artery.

• The head of the pancreas and the proximal part of the duodenum receive their blood supply from the anterior and posterior pancreaticoduodenal arcades. These arcades lie on the surface of the pancreas, close to the duodenal loop. Any attempts to separate the two organs results in ischemia of the duodenum.

• The body and tail of the pancreas receive their blood supply mainly from the splenic artery. The splenic artery originates from the celiac artery and courses to the left along the superior border of the pancreas. It follows a tortuous route, with parts of it looping above and below the superior border of the pancreas. It gives numerous small and short branches to the body and tail of the pancreas.

• The splenic vein courses from left to right, superiorly and posteriorly to the upper border of the pancreas, inferiorly to the splenic artery. It is not tortuous like the artery. It joins the superior mesenteric vein, at a right angle, behind the neck of the pancreas, to form the portal vein. The inferior mesenteric vein crosses behind the body of the pancreas and drains into the splenic vein.

The portal vein is formed by the junction of the superior mesenteric and splenic veins, in front of the inferior vena cava and behind the neck of the pancreas.

The common bile duct (CBD) courses posterior to the first part of the duodenum, in front of the portal vein, continues behind the head of the pancreas, often partially covered by pancreatic tissue, and drains into the ampulla of Vater, in the second part of the duodenum.