Mechanism of Gallstone-Induced Pancreatitis and Gallstone Formation
How Gallstones Cause Pancreatitis
Gallstones cause pancreatitis through transient obstruction of the ampulla of Vater by a migrating stone, which triggers intraglandular activation of pancreatic enzymes that then enter the circulation and cause local and systemic inflammatory damage. 1
Pathophysiologic Mechanism
The obstructing gallstone blocks the common channel where the pancreatic duct and common bile duct meet at the ampulla of Vater, preventing normal drainage of pancreatic secretions 1
This obstruction leads to intraglandular activation of pancreatic enzymes through an unclear mechanism, though the exact biochemical pathway remains incompletely understood 1
Once activated within the pancreas, these enzymes enter the systemic circulation and cause most of the local pancreatic injury and systemic complications characteristic of acute pancreatitis 1
In rare cases, a gallstone can migrate directly into the pancreatic duct itself rather than just blocking the ampulla, though this is uncommon 2
Clinical Context
Gallstones are the leading cause of acute pancreatitis, accounting for 50-75% of all cases in Western populations 3, 4, 5
The obstruction is typically transient—the stone either passes into the duodenum or falls back into the common bile duct 1
Most patients with gallstone pancreatitis experience mild disease and make a full recovery with supportive care 6
What Causes Gallstones
While the provided evidence focuses primarily on gallstone pancreatitis rather than gallstone formation mechanisms, the available data indicates:
Epidemiology of Gallstone Formation
By age 75, approximately 35% of women and 20% of men have developed gallstones 7
The risk of gallstones is increased in patients with Crohn's disease but not ulcerative colitis 7, 8
Important Clinical Caveat
Most gallstones remain asymptomatic throughout a patient's lifetime—the patient often remains completely unaware of their presence 7
There is an association between gallstones and gallbladder cancer, though it has not been definitively proven that gallstones directly cause the cancer—an alternative theory suggests a common underlying factor (such as bile composition) may cause both conditions 7
Clinical Implications
The key clinical priority is recognizing that gallstone pancreatitis requires different management based on severity, with mild cases requiring same-admission cholecystectomy and severe cases requiring ICU-level care with potential urgent ERCP 3, 6, 5