Posterior inferior pancreaticoduodenal artery

The posterior inferior pancreaticoduodenal artery (PIPDA) is a branch of the inferior pancreaticoduodenal artery (IPDA), which itself typically arises from the superior mesenteric artery (SMA). It courses along the posterior aspect of the pancreatic head and duodenum, forming the posterior pancreaticoduodenal arcade by anastomosing with the posterior superior pancreaticoduodenal artery (PSPDA), a branch of the gastroduodenal artery. This arcade provides critical blood supply to the posterior surface of the pancreatic head and the adjacent duodenal wall.

Origin and Variations

The PIPDA most commonly originates from a common inferior pancreaticoduodenal trunk shared with the anterior inferior pancreaticoduodenal artery (AIPDA). However, its origin is notably variable. It may arise from:

• The IPDA as a common trunk with the AIPDA (most common pattern)

• Directly from the SMA as a separate branch

• A common trunk with the AIPDA and the first jejunal artery

• The dorsal pancreatic artery

• A replaced right hepatic artery originating from the SMA

When the AIPDA and PIPDA arise separately from the SMA, the PIPDA origin tends to be located more proximally (closer to the SMA origin), approximately 19 mm from the AIPDA origin. The posterior arcade formed by the PIPDA and PSPDA is present in approximately 88-93% of individuals, being absent in roughly 7-20% of cases.