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Choledochal Cyst



Related narrative: Choledochal Cyst

Cystic dilatation of the bile ducts was first described by Vater and Elzer in 1723. The 1959 classification by Alonso-Lei was modified to include both intrahepatic and extrahepatic variants by Todani in 1977. Type I cysts comprise the majority (70-80%) of cases. Type IA cysts are cystic dilatation of the common duct, IB saccular, and IC fusiform. Type II is a supraduodenal diverticulum of the common duct. Type III is intraduodenal (choledochocele). Type IVA is multiple intra- and extrahepatic cysts, IVB is extrahepatic cysts only, and type V is intrahepatic only (Caroli's disease). Type IV is the second most common type (13-19%).

Incidence in the west is 1:13,000 and in Japan 1:1,000 with female predominance (up to 8:1). Most (70%) are diagnosed in the first decade of life, but the incidence of adult diagnosis is increasing. Childhood choledochal cyst usually presents with jaundice (71% v 25%), pain and abdominal mass, while the adult form manifests less specifically with pain (97%), pancreatitis, cholangitis, choledocholithiasis and ultimately in some cases progression to cirrhosis and portal hypertension.

Proposed etiologic factors have included genetics, embryologic mishaps, viral infection, environment, ductal obstruction and anomalous pancreaticobiliary duct junction. The latter two are currently thought to be the major factors in types I-IV, while type V, Caroli's is thought to be congenital and associated with hepatic fibrosis and autosomal recessive renal cyst disease. Obstruction due to sphincter of Oddi blockage, dysautonomia or web is thought to cause increased pressure. Anomalous/long (>15mm) pancreatobiliary junction is present in the great majority (80-100%) of cases and is postulated to cause inflammation, weakening of the bile duct wall, fibrosis and obstruction by early activation of refluxed pancreatic enzymes. The chronic inflammation caused by the presence of these enzymes is postulated to cause the 15-30% lifetime risk of cholangiocarcinoma both in the cyst and in the rest of the biliary system.

Ultrasound and MRCP are the most useful diagnostic tools. The MRCP helps define ductal anatomy and aids pre-operative planning.

Complications include pancreatitis, found in 30-70% of adult cases, cholangitis due to stones and stasis, and cholangiocarcinoma. The incidence of carcinoma increases with age (mean age 32). Between 10 and 30% of resected cysts harbor carcinoma. Most carcinomas appear on the posterior wall. Type III cysts (choledochocele) appear to have a lower incidence of carcinoma, but are less well studied. The presence of biliary mucosa vs. duodenal may increase the possibility of malignant transformation of type III cysts.

Treatment for type I cysts is complete excision with Roux-Y hepaticojejunostomy. Due to chronic inflammation, the incidence of anastomotic stricture is higher than that for anastomosis of a normal bile duct (3%). If there is dense fibrotic adherence of the cyst to the portal vein because of chronic inflammation, the non-adherent cyst wall is resected and the mucosa of the posterior wall ablated by curettage or cautery (Lilly technique).

Type II diverticula are resected and the common duct closed over a T-tube. Type III choledochoceles less than 3cm are treated with Endoscopic sphincterotomy or open sphincteroplasty. Greater than 3cm cysts are excised transduodenally. If there is suspicion of (rare) carcinoma in a type III cyst, pancreaticoduodenectomy may be indicated.

The extrahepatic components of type IV cysts are excised and the intrahepatic portions left alone unless complicated by stones, stricture or abscess which may necessitate resection. Bilobar type IV disease remains a high risk for cholangiocarcinoma and definitive treatment may be transplantation. Type V Caroli's disease may be treated by resection if only one lobe is involved. bilobar Caroli's may also ultimately require transplantation.


Edil B et. al.:Choledochal cyst disease in children and adults: a 30-year single-institution experience; JACS, 206(5); May 2008, pp1000-1005

This page was last modified on 5-May-2009.