The sphincter of Oddi (also hepatopancreatic sphincter or Glisson's sphincter), abbreviated as SO,[1] is a muscular valve that in some animals, including humans, controls the flow of bile and pancreatic juice out of the gallbladder and pancreas respectively through the ampulla of Vater into the second part of the duodenum. It is named after Ruggero Oddi.
The sphincter regulates the secretion of pancreatic juice and bile into the duodenum.[3] It also prevents reflux of duodenal contents into the ampulla of Vater.[4] By preventing reflux of the contents of the duodenum, the sphincter of Oddi prevents the accumulation of particulate matter and sludge in the bile ducts, reducing the risk of cholangitis. The sphincter of Oddi also allows retrograde filling of the gallbladder.[5]
Pancreatitis can result from a failure of pancreatic secretions to drain properly. One possible cause of impaired drainage of pancreatic juice is blockage of the sphincter of Oddi. A common cause of blockage is a gallstone in the common bile duct.[citation needed]
Opiates may cause spasms of the sphincter of Oddi, leading to increased serum amylase levels.[9]
History
The sphincter was described for the first time by Ruggero Oddi when he was a young student in 1887.[10] This description followed extensive research into the physiology of dogs and detailed histological examinations of humans and many other species.[1]
^Druart-Blazy A, Pariente A, Berthelemy P, Arotçarena R (December 2005). "The underestimated role of opiates in patients with suspected sphincter of Oddi dysfunction after cholecystectomy". Gastroenterol. Clin. Biol. 29 (12): 1220–3. doi:10.1016/s0399-8320(05)82204-3. PMID16518275.
^Ono K, Hada R (July 1988). "Ruggero Oddi. To commemorate the centennial of his original article--"Di una speciale disposizione a sfintere allo sbocco del coledoco"". Jpn J Surg. 18 (4): 373–5. doi:10.1007/bf02471459. PMID3050213. S2CID30812172.