A case of the pathogenesis of choledochocele in relation to dysfunction of the sphincter of Oddi

Choledochocele demonstrated by computed tomographic cholangiography: report of a case

Choledochocele is a rare cystic congenital malformation of the distal common bile duct, the precise pathogenesis of which remains unclear. It is usually diagnosed in adulthood after many examinations for unclear digestive symptoms, as in the patient whose case is described herein. Of all the diagnostic techniques available, endoscopic retrograde cholangiography (ERCP) seems to be the best; however, it is an invasive procedure associated with some morbidity. Spiral computed tomographic cholangiography with three-dimensional reconstruction is also an interesting screening technique. Malignant transformation of a choledochocele occurs very rarely, compared with other cystic malformations of the biliary tract. If a choledochocele is small and symptomatic, the lesion can be treated by endoscopic sphincterotomy, but larger cysts are more effectively removed by a surgical cystoduodenostomy. We present herein the case of a 25-year-old woman admitted to our hospital in March 1998 with upper right quadrant abdominal pain caused by a choledochocele, who was successfully treated by a cystoduodenostomy.

Dilated common channel syndrome: endoscopic diagnosis, treatment, and relationship to choledochocele formation

BACKGROUND

Choledochoceles (type III biliary cysts) are cystic dilations of the terminal common bile duct or common pancreatobiliary channel. Although no size criteria have been defined, it is generally assumed these must be large. However, we describe patients who do not meet the perceived size criteria for choledochoceles, but who nonetheless have a dilated common pancreatobiliary channel.

METHODS

We reviewed the presenting symptoms, endoscopic and radiographic findings, and response to endoscopic therapy of patients meeting our criteria for the dilated common channel syndrome.

RESULTS

Of 2847 patients undergoing ERCP, 100 (3.5%) had the dilated common channel syndrome. Common presenting symptoms and signs included abdominal pain in 97%, abnormal liver function test(s) in 66%, and a history of acute or recurrent pancreatitis in 46%. A bulge was visible above the papilla in 88%, with a dilated common bile duct in 54% and a dilated pancreatic duct in 28%. After endoscopic unroofing of the common channel, 77% had complete and long-lasting resolution of symptoms, 18% had partial or transient improvement, and 5% had no change.

CONCLUSIONS

Although classic choledochoceles are rare, a lesser degree of dilation of the common channel is more frequent than generally appreciated. We postulate that this finding represents an "incomplete," acquired form of choledochocele, possibly caused by underlying papillary stenosis. Whatever the etiology and appropriate term, the presence of a dilated common channel predicts a high rate of clinical response to endoscopic therapy.