What are the types of pancreatic divisum?

Types of Pancreatic Divisum

Pancreatic divisum is classified into two main anatomic types: complete (classic) pancreatic divisum and incomplete pancreatic divisum, both resulting from failure of fusion between the dorsal and ventral pancreatic ductal systems during embryogenesis. 1, 2, 3

Complete (Classic) Pancreatic Divisum

Complete pancreatic divisum represents total failure of fusion between the ventral and dorsal pancreatic ducts, resulting in two completely separate ductal systems with independent drainage. 2

• The dorsal duct (duct of Santorini) drains the majority of the pancreas (body and tail) through the minor papilla 1
• The ventral duct (duct of Wirsung) drains only a small portion of the pancreatic head through the major papilla 1
• MRCP demonstrates non-communicating dorsal and ventral ducts with independent drainage sites and a dominant dorsal pancreatic duct 2
• Complete pancreatic divisum occurs in approximately 1-6% of patients undergoing endoscopic retrograde cholangiopancreatography, with population prevalence estimates of 6-10% 1, 3, 4

Incomplete Pancreatic Divisum

Incomplete pancreatic divisum involves inadequate or partial communication between the ventral and dorsal pancreatic ducts, creating a functionally insufficient connection. 5

• A small communicating branch exists between the dorsal and ventral systems, but it is inadequate for proper drainage 5
• The clinical implications and prevalence of pancreatitis in incomplete pancreatic divisum are similar to complete pancreatic divisum 5
• Patients with incomplete pancreatic divisum who abuse alcohol universally develop chronic or acute pancreatitis 5
• The prevalence of chronic pancreatitis in incomplete pancreatic divisum is significantly higher than in controls without this anomaly (P=0.001) 5

Additional Anatomic Variant

A dorsal duct type variant has been described, though it is much less common than the complete and incomplete forms. 4

• This represents a rare anatomic configuration identified in surgical series 4
• Specific anatomic details distinguishing this from other types are limited in the literature 4

Clinical Significance of Classification

Both complete and incomplete pancreatic divisum can lead to impaired drainage of pancreatic secretions through the dorsal-dominant system, resulting in increased intraductal pressures that trigger recurrent acute pancreatitis. 1, 3

• The majority of patients with either type remain completely asymptomatic throughout their lives 1, 2
• Among symptomatic patients not abusing alcohol, complete pancreatic divisum is suspected as the cause of pancreatitis-like disease in 39% of cases, while incomplete divisum accounts for 30% 5
• ERCP remains the gold standard for definitively diagnosing and classifying pancreatic divisum types 2, 3
• Secretin-enhanced MRCP improves diagnostic yield compared to standard MRI/MRCP for detecting and characterizing both types 1, 2