Neck of the Pancreas

The neck of the pancreas is a short, narrow segment of the gland that connects the head and uncinate process to the body. Though small in size, it is anatomically and clinically significant due to its proximity to key vascular structures, particularly the confluence of the superior mesenteric and splenic veins — which together form the portal vein. Its precise anatomical location makes it a critical landmark during surgical procedures such as the Whipple operation or distal pancreatectomy.

Structure

The neck is approximately 2 cm wide and lies anterior to several important vessels. It contains pancreatic parenchyma with both exocrine acini and scattered islets of Langerhans. The main pancreatic duct (duct of Wirsung) passes through it, continuing from the head into the body of the pancreas.

Structurally, it acts as a bridge:

• Laterally — connects the head to the body

• Posteriorly — lies over major vessels

• Anteriorly — covered by peritoneum and sometimes by the pylorus or stomach

Location

The neck of the pancreas lies anterior to the junction of several major vessels and inferior to the pylorus of the stomach. It is retroperitoneal and located in the upper abdomen, just left of the midline at the level of the first lumbar vertebra (L1).

Structure Relation to Pancreatic Neck Portal vein Formed posterior to the neck by the union of the superior mesenteric and splenic veins Superior mesenteric vein (SMV) Passes directly posterior to the neck Superior mesenteric artery (SMA) Located just posterior and inferior to the neck Pylorus May lie anterior to the neck

Function

The neck contributes to the dual roles of the pancreas — digestive (exocrine) and hormonal (endocrine):

• Exocrine role: Secretes digestive enzymes through the main pancreatic duct into the duodenum. The duct continues uninterrupted from the head, through the neck, and into the body.

• Endocrine role: Houses islets of Langerhans, though these are more concentrated in the tail. Still, the neck contributes to insulin and glucagon production.

• Conduit role: Serves as a key anatomical passage for pancreatic secretions moving from the head toward the duodenum and for blood vessels passing behind it.

Clinical Significance

The neck of the pancreas, though short, is surgically and radiologically vital:

• Pancreatic cancer: Tumors here can compress or infiltrate the portal vein or SMV, complicating surgical resection.

• Whipple procedure: During pancreaticoduodenectomy, the neck is transected to separate the head from the body and tail. This must be done with precision to avoid injuring the portal vein.

• Pancreatic trauma: Blunt trauma to the upper abdomen may cause transection at the neck, leading to pancreatic ductal injury and leakage of enzymes.

• Radiologic landmark: CT or MRI scans of the neck help assess the patency of the portal vein and detect space-occupying lesions.

Due to its close relationship with the portal circulation and pancreatic ductal system, the neck of the pancreas serves as a central landmark for staging pancreatic disease and guiding complex abdominal surgeries.