Presentation
Upper abdominal pain and weight loss. Normal liver function testing on labs, normal lipase. Prior cholecystectomy.
Patient Data
Postcholecystectomy.
Dilated intrahepatic biliary ducts, dilated and tortuous common bile duct, mildly dilated pancreatic duct.
Cyst in upper pole of right kidney.
No mass in head of pancreas.
Similar findings as MRCP and no stones or mass seen on ERCP.
Sphincterotomy was performed without any complications.
Case Discussion
Sphincter of Oddi (SOD) dysfunction is a clinical syndrome described when the flow of pancreatic enzymes or biliary excretions are obstructed from entering the duodenum through the sphincter of Oddi. It can be caused by SOD stenosis (narrowing of the SOD) or SOD dyskinesia (smooth muscles disturbances of the SOD). The exact prevalence is difficult to estimate due to differences in nomenclature, the extent of exploring other causes of symptoms, diagnostic criteria, and lack of adequate control groups. However, data suggests that SOD dysfunction is more common in females than males, possibly due to the same risk factors for cholelithiasis, and may sometimes be referred to as post-cholecystectomy syndrome. One study revealed that 14-23% of patients with post-cholecystectomy syndrome had SOD dysfunction.
Treatment of SOD dysfunction can be subdivided into three types with respect to clinical manifestations. All types present with biliary-type pain. Type I SOD is characterized by the addition of abnormal liver enzymes and dilation of the common bile duct. Type II SOD will present with either abnormal liver enzymes or dilation of the common bile duct. Type III SOD will present with neither. The gold standard for diagnosis is SOD manometry of both the common bile duct and the pancreatic duct. Recent studies stratify the need for SOD manometry and subsequent sphincterotomy depends on the patient’s type of SOD.
SOD dysfunction is a disorder that should be suspected in patients with complaints of chronic biliary pain or recurrent episodes of pancreatitis not explained by other causes. Due to the lack of uniformity in research, uncovering the underlying cause of SOD dysfunction is difficult. Some possible explanations for the underlying pathophysiology include progressive inflammation or scarring from pancreatitis or passage of gallstones. It is important to include possible congenital papillary stenosis as a cause.