Anatomy - Duodenohemipancreatectomy with Blumgart anastomosis and biliopancreatic separation

The pancreas, composed of lobules, has a reddish-gray color, is 14 – 18 cm long, and weighs 65 – 80 grams. It is located at the level of the 1st and 2nd lumbar vertebrae and extends wedge-shaped from the epigastric region into the left hypochondriac region. Due to its developmental history, the organ is in close proximity to the upper abdominal organs and vessels.

The pancreas is encased in capsule-like connective or fatty tissue and is divided into three sections: head, body, and tail. While a somewhat firmer connective tissue plate is located in the posterior head region, the gland is otherwise predominantly loosely connected dorsally with the connective tissue. As a retroperitoneal organ, the gland is covered on its anterior surface with peritoneum.

The widest part of the gland is the head of the pancreas, which, located to the right of the spine, fits into the loop formed by the duodenum. Both the anterior and posterior surfaces of the duodenum can be overlapped by glandular tissue to varying extents here. The head encompasses the superior mesenteric vein from behind with its caudal portion (uncinate process), occasionally also the artery. The groove located in the uncinate process and the rest of the pancreatic head is referred to as the pancreatic notch.

The part of the pancreas located at the level of the 1st lumbar vertebral body represents the transition area from the head to the body and lies over the superior mesenteric vessels. From a surgical perspective, this section is also referred to as the neck of the pancreas.

The elongated body of the pancreas runs obliquely upward over the 1st and 2nd lumbar vertebrae, bulges ventrally into the omental bursa, and arches towards the splenic hilum, with the transition into the tail occurring without precise anatomical demarcation. Dorsal to the body are the aorta, inferior vena cava, and superior mesenteric artery and vein, alongside the spine.

The tail of the pancreas forms the pointed continuation of the glandular body and extends to or into the splenorenal ligament.

The pancreas can be configured in various shape variants, including obliquely running, S-shaped, transversely running, and L-shaped. A horseshoe shape and an inverted V-shape have also been described. The transitions between the shape variants are fluid.

Topographically, the pancreas has the following relationships to neighboring organs and retroperitoneal conduits:

• ventrally, the omental bursa and the posterior surface of the stomach
• to the right, there is a close relationship between the head and the duodenal loop
• to the left, there is a close relationship to the splenic hilum
• the posterior wall of the pancreas touches at the level of the head the portal vein, the superior mesenteric artery and vein, as well as the common bile duct, at the level of the body the splenic artery and vein, the inferior mesenteric vein, the inferior vena cava, and the abdominal aorta, at the level of the tail the left kidney

The approximately 2 mm thick Ductus pancreaticus traverses the organ in its longitudinal extension near the posterior surface and receives numerous short glandular ducts along its path, which enter it perpendicularly. In about 77% of cases, the duct joins with the Ductus choledochus at the Papilla duodeni major in the posterior wall area of the descending part of the duodenum; in the remaining cases, the openings of both ducts are close to each other. The Ductus pancreaticus accessorius, an accessory duct, is often only rudimentarily developed or completely absent. If present, it opens at the Papilla duodeni minor.