What is Pancreatic Divisum
Pancreatic divisum is the most common congenital pancreatic anomaly, occurring in approximately 6-10% of individuals, resulting from failure of fusion between the dorsal and ventral pancreatic ductal systems during embryonic development. 1, 2
Embryologic Basis and Anatomic Configuration
The condition arises when the ventral and dorsal pancreatic buds fail to fuse during fetal development, leaving the two ductal systems draining separately into the duodenum 3, 4, 5
In pancreatic divisum, the dorsal duct becomes the dominant drainage system and empties through the minor papilla, while the ventral duct (duct of Wirsung) remains small (1-6 cm long, 2 mm diameter) and drains only the posterior head of the pancreas through the major papilla 3
Both classic and incomplete variants exist, though both can lead to impaired pancreatic secretion drainage 2
Clinical Significance and Natural History
The majority of patients with pancreatic divisum remain completely asymptomatic throughout their lives 1, 6
Only approximately 5-25% of individuals with pancreatic divisum develop symptomatic disease, typically manifesting as recurrent acute pancreatitis, chronic pancreatitis, or chronic abdominal pain 5, 6
The pathophysiologic mechanism in symptomatic cases involves impaired drainage of pancreatic secretions through the dorsal-dominant system, resulting in increased intraductal pressures that can trigger pancreatitis 1
Symptomatic patients are typically young (mean age 29 years), predominantly female, and lack significant alcohol abuse history, contrasting with incidentally detected cases who tend to be older males with hepatobiliary disease 3
Diagnostic Approach
Endoscopic ultrasound (EUS) is the preferred initial diagnostic modality for evaluating unexplained acute and recurrent pancreatitis, with MRI/MRCP serving as complementary or alternative testing 1, 2, 7
MRCP is particularly valuable for identifying pancreatic ductal anatomical variants, demonstrating non-communicating dorsal and ventral ducts, independent drainage sites, and a dominant dorsal pancreatic duct 1, 8
Secretin-enhanced MRCP can improve diagnostic yield compared to standard MRI/MRCP, though clinical utility may be limited by availability and interpretation variability 1
ERCP remains the gold standard for definitively diagnosing and classifying pancreatic divisum types, though it should not be performed solely for diagnostic purposes due to associated risks 2, 7
The radiologic appearance shows a characteristically short, thin pancreatic duct (duct of Wirsung) with regular arborization draining only the posterior pancreatic head 3
Important Diagnostic Pitfalls
False pancreatic divisum can be simulated by previous pancreatic trauma, partial pancreatectomy, pancreatitis with irreversible ductal damage, pseudocyst, or pancreatic carcinoma—differentiation is clinically critical 3
Pancreatic divisum is also classified as an anatomic variation rather than a pathologic finding in cancer screening protocols, requiring no follow-up when incidentally detected 9
In children with recurrent pancreatitis, pancreatic divisum should be considered after excluding more common etiologies including gallstones, medications, and metabolic disorders 7, 4