by Harwood Academic Publishers Printed in Malaysia Cystic Dilatations of the Common Bile Duct in Adults

Cystic dilatations of the common bile duct are believed to be of congenital etiology with most cases presenting in childhood. During the last 20 years, 10 patients with cystic dilatations of the bile duct were treated in our Department. There were 5 men and 5 women with an age range of 35–81 years. Clinical presentation consisted of right hypohondrial pain, nausea, vomiting and a history of obstructive jaundice. Diagnosis was established by ultrasound, cholangiography and ERCP in most cases. According to the Todani classification system, 5 patients had type I cysts, 4 had type II and one had type III. At the time of surgery, main associated diseases were choledocholithiasis in 3 cases and cholangitis in 2 cases. One patient (type III) underwent endoscopic sphincterotomy; 4 patients underwent internal drainage and 2 of them developed mild cholangitis postoperatively; 5 patients underwent excision of the cyst and a biliary-enteric bypass and developed no main complications. Patients remained in good health during long-term follow-up. We conclude that cyst excision is the treatment ofchoice for adults in order to reduce postoperative morbidity and the potential risk of malignancy.

Cystic dilatations of the common bile duct, the socalled choledochal cysts are rather rare congenital malformations of the pancreatico-biliary system; their incidence ranges from in 13,000 to one in 2 million live births1. They are usually a surgical problem of infancy or childhood; however in approximately 20% of cases, diagnosis is established during adulthood2. There is a strong predilection for Asians: more than 75% of reported cases come from the Japanese litera-ture3. During the last two decades they are found with increasing frequency due mainly to the advent ofmodern imaging techniques.
There are controversies concerning surgical management of choledochal cysts. Early reports suggested that internal drainage procedures were acceptable surgical treatment; however, long-term follow-up proved Correspondence to: Gregory Kouraklis, MD, FACS 122 Vasilisis Sophias Avenue Athens 11526 Greece Tel. (01)-7772181 Fax (01)-7791456 that they are followed by a high rate of late complications. Currently, cyst excision with biliary reconstruction has been recognized as the procedure ofchoice for choledochal cysts4'5'6.
The present study describes our experience with cystic bile duct dilatations, analyzing the clinical findings, classification, surgical management and longterm results. 91

PATIENTS AND METHODS
Between January 1975 and December 1994, 10 adult patients with choledochal cysts were treated at the 2nd Department of Propedecutic Surgery of Athens University Medical School. Sex, age at operation, clinical symptomatology, associated diseases, laboratory, radiographic and histopathological findings, surgical management and postoperative morbidity and mortality were recorded. Choledochal cysts were classified according to the Alonso-Lej classification with Todani modifications, based on radiographic and operative findings.
Follow-up was obtained by review of medical records, follow-up visits and telephone calls to patients. The results were considered good if patients were asymptomatic or had rare mild episodes of cholangitis that were treated conservatively. Hepatomegaly was present in one patient with cholestatic cirrhosis. Three patients had laboratory evidence of hepatocellular dysfunction and only one patient had mild hyperamylasemia. Seven patients had associated cholelithiasis, choledocholithiasis or cystolithiasis. Calculi were most often bilirubinate and were associated with thick viscous bile and/or sludge.
The standard imaging methods for the diagnosis of biliary tract disease were used in our patients. Ultrasonography was the least accurate method in diagnosing choledochal cysts preopeatively. Only endoscopic retrograde cholangio-pancreatography (ERCP) and intravenous cholangiography clearly defined anatomy of the extrahepatic biliary system. However, diagnosis was not made until operation in 3 cases (Table 1).
Nine patients underwent laparotomy. No patient had undergone a previous operation. Operative cholangiography was carried out for 7 patients. Cyst size ranged from to 4.5 centimeters. A chronic inflammatory reaction was present in 4 cases.
A variety of operations were performed. Four patients with a type I cyst that were treated early in the series had cystoduodenostomy performed. One patient with a type ! cyst underwent cyst excision and Roux-en-Y hepaticojejunostomy. Four patients with a type I! cyst underwent cyst excision followed by a drainage procedure: choledochoduodenostomy was performed in 3 of them and a Roux-en-Y choledochojejunostomy in one patient. Concurrent cholecystectomy was perfomed in all 9 patients. One patient with a choledochocele (type III cyst) and concomitant choledocholithiasis underwent endoscopic sphincterotomy and stone extraction (Fig. 1).
Histopathologic examination of the surgical specimens revealed that the wall of the choledochal cysts was composed almost exclusively of fibrous connective tissue with a patchy collumnar epithelium as a mucosal lining. Inflammation and mucosal ulceration were present. Chronic cholecystitis was found in 5 patients.
Postoperatively, there was one bile leak that sealed without surgical intervention in a patient undergoing cystoduodenostomy. Two of the early cases treated with internal drainage were lost to long-term followup, after an interval of 3 and 4 years during which they did well. At a mean follow-up of 36 months, 2 patients with type I cysts who underwent internal drainage, presented with rare mild episodes of cholangitis that resolved conservatively. One patient had a biopsy proven mild cholestatic cirrhosis two years after operation and is in a good general condition. No patient with a retained cyst presented with malignancy. The patient with a choledochocele treated nonoperatively is doing well 2 years after the endoscopic procedure.

DISCUSSION
There is still controversy regarding the pathogenesis of choledochal cysts. Yotsuyanagi in 1936 proposed that choledochal cysts arise from inequality in the cellular proliferation ofthe biliary tract in the early fetal life. Babbitt 1 in 1969 proposed the common channel theory, which is the most widely accepted: patients with cystic bile duct dilatations have an anomalous entry of pancreatic ducts into the bile duct system in such a way that there is a true common channel resulting in easy reflux of pancreatic juice into the duct due to absence of the sphincter of Oddi. In 1959, Alonso-Lej et al. developed the first classification system which included type I, II and III choledochal cysts, as are presented in our work. Todani et al. in 1977 modified the classification system by adding type IV-A and B and type V cysts. According to previous statistics, type I cysts are reported to make up 85% to 90% of all reported cases worldwide11, type II cysts occur in less than 2% of cases4, type Ill cysts in approximately 2% of cases and type IV cysts occur in 10% of cases4.
Clinical symptomatology of choledochal cysts varies widely. The classic triad of pain, mass and jaundice described by Alonso-Lej and co-workers is seen in only one third of cases1'7'12. In our series most patients had a history of obstructive jaundice where only one patient had a mild hyperamylasemia. The prevalence of hepatobiliary disease, i.e. concurrent lithiasis was greater in our series than usually reported2'13; this probably reflects advanced age of our patients and prolonged bile stasis14.
Between the diagnostic modalities, ultrasonography is considered as one of the best imaging methods for diagnosing choledochal cysts6. However in our series it_s diagnostic accuracy was low. CT scan is useful for revealing associated intrahepatic disease, whereas ERCP and transhepatic cholangiography (PTC) provide the most accurate means for the preoperative examination of the biliary anatomy1'12.
The conventional surgical approach to choledochal cysts is internal drainage of the cyst into the duodenum orjejunum. This was the procedure we performed in our four early cases of type I cysts. However, longer follow-up revealed that severe late complications such as anastomotic stricture, recurrent cholangitis, lithiasis, pancreatitis, cirrhosis, portal hypertension and carcinoma of the bile duct occured in up to 30-50% of cases3'4'11 '15'16'17. Kasai was the first to report the increased incidence of bile duct carcinoma arising in cystic bile duct dilatations and proposed surgical excision18. Consequently surgical excision and biliary reconstruction is considered now as the procedure of choice. For type I cysts, total excision of the cyst or exizision by the method described by Lilly1'9'2, followed by Roux-en-Y hepaticojejunostomy and cholecystectomy should be performed, as was done in one of our cases. For type II cysts, excision with bile duct repair is indicated, as was done in our cases of type II cysts. Type III cysts are best managed by transduodenal sphincteroplasty or endoscopic sphincterotomy without cyst excision, because of the 382122 low risk of carcinoma" This was done in one of four cases of a small type III cyst, using the endoscopic method, and the clinical result was excellent. However an alternative approach by total excision followed by reimlantation of the bile duct and the major pancreatic duct to the duodenal mucosa could 13 23 be performed No cases of type IV and V cysts occured in our series.
There is still controversy about the management of patients who have undergone internal drainage procedures in the past. There is no doubt that patients with retained cysts carry a lifetime risk of cholangiocarcinoma, which is associated with a dismal prognosis. For that reason, some authors advocate that these patients should undergo a secondary cyst excision6. In our series, patients with retained cysts did not developed any severe complications requiring reoperation, except for mild cholangitis in two cases that was managed conservatively and biliary cirrhosis in another case which should rather be attributed to late diagnosis. Further more, no malignancy occured in patients with retained cysts. It is also widely accepted, that excision does not completely eliminate the risk of malignancy, because 40% of cases of cholangiocarcinoma occur outside the cyst3'6. We are in accordance with other authors 3'14 who do not recommend reoperation in asymptomatic patients with retained cysts, but meticulous follow-up using biochemical and diagnostic imaging tests, in frequent intervals, during their lifetime.

Invited Commentary
Although the typical patient with choledochal cyst has been the young girl (below 10 years of age) presenting with jaundice, abdominal mass and pain, the condition is actually recognised more often in adults1. Dr. Kouraklis and colleagues report 10 patients, no less than 4 ofwhom had type II choledochal cyst. This type makes up no more than 7% in most series2-4, and it is unusual to find more than 2 cases in any one series. The authors do not define the entity of choledochal cyst. Only four patients in their series had an endoscopic retrograde cholangiopancreatogram (ERCP), none had percutaneous transhepatic cholangiography (which often gives the best delineation) and two had an intravenous cholangiogram, which generally gives poor definition of bile duct diameter. They are therefore relying upon operative interpretation of bile duct size, which ranged from 1.0 to 4.5 cm. Perhaps this limited investigation explains the apparent lack of any intrahepatic biliary dilatation.
In the present series, ultrasonography was surprisingly poor in diagnosing the cyst, with an accuracy rate of 25 per cent, compared with up to 90% in other series5'6, even when performed antenatally7. Ultrasound scan can sometimes fail to identify extrahepatic biliary dilatation, however, because of the problem with overlying bowel gas8.
As the authors state, resection of the cyst and bile duct reconstruction is preferable to simple cyst drainage, and their results endorse this fact. Of four patients receiving cyst drainage, two have had recurrent cholangitis and surely need reoperation. The other two are lost to follow-up and must be at some risk ofdeveloping cholangiocarcinoma. It is generally agreed that up to 75% of patients need further operation after an internal drainage2'8'9'1. In high-risk patients, endoscopic sphincterotomy could be useful if the cause of the recurrent infection were a "sump syndrome" following choledochoduodenostomy11; ERCP could also help to show whether the old anastomosis has became stenotic. For patients with type II cyst, excision with bilioenteric anastomosis is usually advocated as the best treatment3. Alternatively the cyst can be excised at its junction with the common duct, closing the defect either primarily or with T tube decompressions.