Published in:
01-12-2013 | Original Article
The mucosal folds at the pancreaticobiliary junction
Published in: Surgical and Radiologic Anatomy | Issue 10/2013
Login to get accessAbstract
Purpose
The structure and function of the mucosal folds in the terminal bile and pancreatic ducts and hepatopancreatic ampulla are poorly characterised. The distribution, muscularity, and innervation of these folds were investigated.
Methods
The pancreaticobiliary junction was excised from ten cadavers (five male, 66–90 years) and examined histologically by serially sectioning (4-μm thickness) along the length of the terminal bile and pancreatic ducts from the tip of the major duodenal papilla. Three surgical specimens (two male, 63–72 years) were also evaluated. Sections were stained with haematoxylin and eosin, anti-actin (smooth muscle), anti-S100 (innervation), and anti-cholecystokinin (CCK)-A receptor antibodies. ImageJ software was used to compare relative radial fold projection and semi-quantitatively assess the smooth muscle and nerve content. In one additional cadaver specimen, folds were examined by scanning electron microscopy.
Results
Mucosal folds in the terminal bile duct were arranged circumferentially in a lattice-like arrangement and were distributed over an average distance of 7.3 mm along the terminal bile duct compared to 4.2 mm along the pancreatic duct (P = 0.001), projected further into the lumen, and were more densely innervated than those in the terminal pancreatic duct. Folds in both ducts contained smooth muscle which was more prominent in folds nearest to the major duodenal papilla. Mucosal folds in cadaver and surgical specimens showed no evidence of CCK-A receptor immunoreactivity.
Conclusions
This study demonstrates that the mucosal folds of the terminal bile and pancreatic ducts contain muscle and nerve fibres, suggesting an active rather than purely passive function.