Inferior pancreaticoduodenal artery

The inferior pancreaticoduodenal artery (IPDA) is a branch of the superior mesenteric artery (SMA) that supplies the head of the pancreas and the duodenum. It typically arises from the SMA or from its first jejunal branch, near the inferior border of the pancreas.

Anatomy and Course

The IPDA divides into two branches an anterior and a posterior branch which anastomose with the corresponding anterior and posterior branches of the superior pancreaticoduodenal artery (a branch of the gastroduodenal artery, itself arising from the common hepatic artery of the celiac trunk). Together, these vessels form the pancreaticoduodenal arcades, which create a critical anastomotic network between the celiac trunk and the SMA circulations.

Key Features

• Origin: Most commonly from the SMA or its first jejunal branch; less frequently it may arise as a common trunk with the first jejunal artery.

• Branches: Anterior inferior pancreaticoduodenal artery and posterior inferior pancreaticoduodenal artery.

• Territory of supply: Inferior portion of the head of the pancreas, the uncinate process, and the third and fourth (horizontal and ascending) portions of the duodenum.

• Anastomotic significance: The pancreaticoduodenal arcades formed by the superior and inferior pancreaticoduodenal arteries represent the principal collateral pathway between the celiac axis and the SMA. This anastomosis becomes clinically important in cases of celiac artery stenosis (e.g., from median arcuate ligament syndrome) or SMA occlusion, where these arcades serve as a compensatory blood supply.

Variant Anatomy

Anatomic variations are frequent. The anterior and posterior branches may arise separately from the SMA rather than from a common IPDA trunk. In some individuals, the IPDA may give rise to a replaced or accessory right hepatic artery, a variant of significant surgical importance.