Peritoneal relations of the pancreas:

The initial and terminal parts of the duodenum are covered by peritoneum, and the superior part of the duodenum is ataached to the liver by the hepatoduodenal ligament.

The rest of the duodenum is retroperitoneal.

The recesses associated with the duodenojejunal junction include;

• Superior duodenal recess
• Inferior duodenal recess
• Retroduodenal recess
• Paradeudenal recess. This recess is guarded by the paraduodenal fold, which contains the inferior mesenteric vein and the superior left colic artery.

These recesses are potential sites of internal hernia.

Arterial:

Mainly from:

•  Superior pancreaticcoduodenal - branch of gastroduodenal.
•  Inferior pancreaticoduodenal - branch of superior mesenteric.

These vessels anastomose.

Other sources include:

•  Supraduodenal artery from hepatic artery.
•  Right gastric artery
•  Right gastroepiploic
•  Gastroduodenal

These vessels also anastomose.

Veins:

In general, these follow the arteries and drain into the portal venous system.

Most drain into superior mesenteric, but some may enter the portal vein directly.

One of the anterior veins – the prepyloric vein (of Mayo) ascends anterior to the pylorus and drains into the right gastric vein. This vein consistently runs over the gastroduodenal junction and is an important guidepost to surgeons.

Posterior and anterior vessels anastomes:

Follow arteries:

• Pancreaticoduodenal
• Gastroduodenal
• Coeliac nodes. (anterior ones)
• The posterior ones
• Superior mesenteric nodes.