Origin and Course
The inferior pancreaticoduodenal artery originates from the right side of the proximal segment of the superior mesenteric artery (a. mesenterica superior).
The superior and inferior pancreaticoduodenal arteries course toward each other parallel to the concave margin of the duodenum, within the groove between the duodenum and the head of the pancreas. Their branches travel along the anterior and posterior surfaces of the pancreatic head and adjacent duodenum.
Branches
The inferior pancreaticoduodenal artery divides into two main trunks:
- Anterior inferior pancreaticoduodenal artery (a. pancreaticoduodenalis inferior anterior / r. anterior) — the anterior branch that runs along the anterior surface of the pancreatic head and adjacent duodenum.
- Posterior inferior pancreaticoduodenal artery (a. pancreaticoduodenalis inferior posterior / r. posterior) — the posterior branch that runs along the posterior surface of the pancreatic head and adjacent duodenum.
Areas Supplied
The inferior pancreaticoduodenal artery participates in the blood supply to:
- Duodenum — descending and inferior parts.
- Pancreas — head (caput pancreatis).
Short, straight branches arise radially from the formed arterial arcades to penetrate the duodenal wall.
Arterial Arcades and Major Anastomoses
The branches of the inferior pancreaticoduodenal artery ascend to meet the superior pancreaticoduodenal arteries, which originate from the gastroduodenal artery (a. gastroduodenalis).
The superior and inferior pancreaticoduodenal arteries anastomose to form two vascular arcades:
- Anterior arterial arcade — formed by the anastomosis of the anterior superior and anterior inferior pancreaticoduodenal arteries.
- Posterior arterial arcade — formed by the anastomosis of the posterior superior and posterior inferior pancreaticoduodenal arteries.
The pancreaticoduodenal arcades serve as a critical collateral pathway linking the celiac trunk and the superior mesenteric artery.
Venous Drainage, Lymphatics, and Innervation
- Venous drainage: via corresponding veins into the v. mesenterica superior et inferior, v. splenica, v. gastrica sinistra, and ultimately into the v. portae.
- Lymphatic drainage: lymph drains into the pancreatic, pancreaticoduodenal, splenic, pyloric, and lumbar lymph nodes (nodi lymphoidei pancreatici, pancreaticoduodenales, splenici, pylorici, lumbales).
- Innervation: supplied by the celiac plexus (plexus coeliacus) and branches of the vagus nerve (n. vagus).
Clinical Significance
Embolism or thrombosis of the superior mesenteric artery leads to acute small bowel ischemia, which represents a life-threatening medical emergency.