Related Experiment Video
Updated: Jun 19, 2026
Robotic-assisted Lateral Pancreaticojejunostomy for Chronic Pancreatitis
Published on: September 5, 2025
Endoscopic evaluation of factors contributing to intrapancreatic biliary stricture in autoimmune pancreatitis
Kenji Hirano1, Minoru Tada, Hiroyuki Isayama
1Department of Gastroenterology, Faculty of Medicine, University of Tokyo, Tokyo, Japan.
Background:
Intrapancreatic bile duct stricture in autoimmune pancreatitis (AIP) is usually diagnosed as sclerosing cholangitis even if the stricture is limited to the intrapancreatic area. However, it is not known whether compression caused by pancreatic edema or biliary wall thickening causes such a biliary stricture.
Objective:
Our purpose was to clarify the factor that contributes to intrapancreatic biliary stricture in AIP: pancreatic head lesion or biliary wall thickening.
Design:
Single-center retrospective study.
Setting:
This study was performed in a tertiary care academic medical center.
Patients:
Fifty-six patients with AIP were included.
Main Outcome Measurements:
The relationship between the presence of a pancreatic head lesion and intrapancreatic biliary stricture was examined. In addition, the relationship between the extent of the intrapancreatic biliary stricture and the wall thickening was evaluated.
Results:
Among 44 patients with a pancreatic head lesion, 41 (93%) had intrapancreatic bile duct stricture. Among 12 patients without a pancreatic head lesion, only 2 had such a stricture (P < .0001). Intraductal US showed average intrapancreatic biliary wall thickening with severe stricture of 2.7 +/- 1.0 mm, significantly thicker than that with mild stricture (1.9 +/- 0.35 mm; P = .0200).
Limitations:
Intraductal US was not performed in all patients.
Conclusions:
Both pancreatic edema and biliary wall thickening influenced intrapancreatic biliary stricture in AIP. This type of stricture should be differentiated from extrapancreatic biliary stricture that may be caused by biliary wall thickening only.
Related Concept Videos
01:24Chronic Pancreatitis I: Introduction
Pancreatitis is the inflammation of the pancreas, which occurs when the immune system becomes active and causes swelling, pain, and disruptions in organ function. Pancreatitis can manifest as either an acute or chronic condition.
Acute pancreatitis arises suddenly and lasts for a brief duration, while chronic pancreatitis is a long-term affliction...
01:25Chronic Pancreatitis I: Introduction
01:21Chronic Pancreatitis II: Pathophysiology
01:29Chronic Pancreatitis II: Collaborative Care
Assessment:
01:25Acute Pancreatitis I: Introduction
01:27Acute Pancreatitis I: Introduction
Acute pancreatitis is characterized by rapid inflammation of the pancreas, often caused by factors like gallstone blockage or excessive alcohol consumption. Chronic pancreatitis, on the other hand, is a slow, progressive inflammation that may result from long-term alcohol abuse, obstructions in the pancreatic duct, or genetic factors.
The causes of acute pancreatitis include: