Clinical and Radiological Findings in Dominance of Santorini's Duct

Abstract

Background and Aims: Few studies on Santorini's duct dominance, in which the ventral pancreatic duct is narrower than and anastomoses with Santorini's duct have been performed. We examined clinical and radiological findings in cases characterized by dominance of Santorini's duct. Methods: We reviewed 3800 cases of endoscopic retrograde cholangiopancreatography. Clinical and pancreatographic findings including caliber, course, terminal shape, and patency of Santorini's duct were examined in cases of Santorini's duct dominance. Results: Twenty-nine cases were diagnosed as Santorini's duct dominant. Chronic pancreatitis, acute relapsing pancreatitis, pancreatic-type pain, and hyperamylasemia not associated with obvious pancreatitis were observed in 3, 1, 5, and 6 cases, respectively. Cholangiopancreatographic findings indicated congenital choledochal cyst (n=2), branch fusion between the ventral and dorsal pancreatic ducts (n=23), and normal pancreatic duct system characterized by a straight course through the body and tail to join the ventral pancreatic duct in the neck portion of the pancreas (n=4). Maximum diameter of the ventral pancreatic duct was less than 1 mm in 13 cases, of which 4 cases showed as slender as 0.5 mm. Maximum diameter of Santorini's duct exceeded 3 mm in 17 cases, and exceeded 4 mm in 5 cases without chronic pancreatitis. Regarding terminal shapes of Santorini's duct, cudgel type (n=9) and spindle type (n=8), which sicantly more frequently than in controls. Patency of Santorini's duct was observed in 90% (17/19). Conclusions: Many Santorini's duct-dominant cases exhibited branch fusion between the ventral and dorsal pancreatic ducts. Although Santorini's duct functions well in most cases in which it is dominant, pancreatitis or pancreatic-type pain occurs in half of such cases due to relative impairment of function of the minor duodenal papilla.