Neck of Pancreas

Overview

The neck of the pancreas is a short but critical region of the pancreas that connects the head to the body. Though small in size, it plays an important anatomical and surgical role, especially due to its close relationship with major blood vessels like the superior mesenteric vein (SMV) and portal vein. It also serves as a key landmark in pancreatic surgeries and imaging.

Location

The neck of the pancreas is located in the upper abdomen, anterior to several major vessels. Specifically, it:

• Lies anterior to the superior mesenteric vein (SMV) and the formation of the portal vein

• Is situated posterior to the pylorus of the stomach

• Is bounded by the head of the pancreas on the right and the body on the left

Its strategic location makes it an important conduit between the exocrine and endocrine functional areas of the pancreas.

Structure

The neck of the pancreas is:

• 2–2.5 cm wide and relatively flat in shape

• Composed of pancreatic parenchyma containing both exocrine acinar cells and endocrine islets of Langerhans

• Traversed by the main pancreatic duct (duct of Wirsung), which carries digestive enzymes toward the duodenum

• Closely associated with vascular structures including the portal vein, SMV, and splenic vein

Function

While the neck does not have a unique function distinct from the rest of the pancreas, it plays an essential part in:

• Pancreatic secretion transport: It serves as a passageway for the main pancreatic duct that carries digestive enzymes to the duodenum

• Blood vessel conduit: It overlies the formation of the portal vein, a critical anatomical and surgical consideration

Physiological Role(s)

The neck of the pancreas supports key physiological processes by:

• Linking exocrine regions: Provides continuity for enzyme production from the head to the body of the pancreas

• Supporting vascular drainage: Positioned at the junction where the splenic vein and SMV join to form the portal vein, which drains nutrient-rich blood from the gut to the liver

• Endocrine integration: Contains islets of Langerhans that release hormones like insulin and glucagon into surrounding capillaries

Clinical Significance

The neck of the pancreas is a critical zone in several medical contexts:

• Pancreatic cancer: Tumors in the neck can compress or invade nearby vessels (e.g., portal vein), impacting surgical resectability and prognosis

• Whipple procedure (pancreaticoduodenectomy): The neck is often transected during this operation; clear margins here are essential for curative resection

• Portal vein involvement: Cancer or inflammation involving the neck can encase or obstruct the portal vein, requiring vascular reconstruction during surgery

• Pancreatic trauma: Blunt abdominal injury may lead to transection or hematoma formation at the pancreatic neck due to its fixed position over major vessels

• Imaging landmark: The neck serves as a key reference point in CT or MRI scans when assessing pancreatic pathology or planning surgery

Accurate identification of the neck of the pancreas is crucial in both diagnostic imaging and operative planning due to its proximity to major vasculature and its role in maintaining pancreatic continuity.