Pediatric Choledochal Cyst Surgery Dr. Hisham Hussein, M.D Assistant Professor of General& Pediatric Surgery Banha Medical School 2011

BACKGROUND  Cystic dilatation of the extrahepatic bile ducts, also known as choledochal cyst, is a fairly uncommon anomaly of the biliary tract.In western countries has been estimated at around 1 in 15,000 live births.  The incidence is much higher in the far east,it may account for up to 1 per 1000 hospital admissions.  The male to female ratio has been variably reported as being between 1:2 and 1:4.  More than 60% of cases present before the age of 10 years,and an increasing number are presenting antenatally as a result of routine ultrasound scanning.

BACKGROUND  It was first described by Vater and Ezler in 1723, Douglas published the first complete clinical description of the anomaly in a patient in  In 1959, Alonso-Lej et al published an extensive review of 94 cases in the literature and added two cases of their own.They classified choledochal cysts into 3 types.  In 1977, Todani et al further classified this anomaly into 5 types. Subsequent subtypes based on cholangiographic findings have been described.

Pathophysiology ♣ The exact cause of choledochal cyst remains obscure. Many authors believe that they are congenital because most of the cysts are diagnosed in infants and children. ♣ However, because approximately 20% are diagnosed in adults, including elderly patients, several theories have been postulated, as follows. * Weakness of the wall of the bile duct. * Obstruction of the distal choledochus. *Combination of obstruction and weakness. * Reflux of pancreatic enzymes into the CBD secondary to an anomaly of the pancreaticobiliary junction (Babbitt’s theory) ♠ The pressure in the pancreatic duct (30-50 cm H2O) exceeds the pressure in the CBD(25-30 cm H2O) favoring reflux of pancreatic secretion into the CBD. ♠ The reflux of pancreatic juice could lead to weakness and dissolution of the wall of the CBD.

Pathophysiology channel theory” stands out as the most likely explanation.

Classification of choledochal cyst ♣ Type I: cystic or fusiform dilatation of the common bile duct (CBD) most frequent type (90-95%) of the cases. ♣ Type II: diverticulum of the CBD with normal size of the CBD. ♣ Type III: choledochocele, a cystic dilatation of the distal intramural portion of the CBD typically protruding into the second portion of the duodenum. ♣ Type IV: cystic or fusiform dilatation of the CBD associated with cystic fusiform or saccular dilatation of the intrahepatic bile ducts (10%). ♣ Type V: cystic fusiform or saccular dilatation of the intrahepatic bile ducts associated with a normal CBD, may be associated with hepatic fibrosis (referred to as Caroli’s disease ) (5%).

Classification of Choledochal Cyst

Clinical Presentation  Choledochal cysts may present at any age, but the majority (up to 60%) are diagnosed before the age of 10y.  Two distinct clinical groups of patients are recognized with regard to age at presentation. ► The infantile group (< 1y). * palpable mass in the right upper quadrant. * obstructive juandice. * acholic stools. * vomiting,fever,abdominal pain and hyperamylasemia

Clinical Presentation ► The older children group (>1year); * jaundice (75%) * abdominal pain (50%) * abdominal mass (30%) ► In general,children tend to present in one of 2 ways; # children with cystic choledochal cysts usually present with a palpable right upper quadrant mass and intermittent obstructive jaundice. # Those with fusiform choledochal cysts usually present with recurrent abdominal pain due to pancreatitis. Classical Triad

DIFFERENTIAL DIAGNOSIS (DD) ► The DD of Choledochal cysts depends upon the mode and timing of presentation, and includes; ♠ Duplication cysts ♠ Biliary atresia ♠ Spontaneous perforation of the CBD ♠ Rhabdomyosarcoma ♠ Simple hepatic cysts ♠ Mucocoele of the G.B ♠ Hepatic tumours ♠ Lesions of the pancreas, kidney and adrenal gland.

DIAGNOSIS ♥ The diagnosis of choledochal cyst is generally straightforward once the possible diagnosis is considered. 1- Ultrasonography is usually the 1 st line investigation of choice it can determine the size the position the shape of the cyst the anatomy of related structures However, it is less useful in the case of fusiform cysts, as there are limitations in its ability to demonstrate the ductal anatomy at the pancreaticobiliary junction.

DIAGNOSIS 2- Plain abdominal radiography; may show * Rt. Upper quadrant mass displaces the bowel * Radio-opaque calculi if these are present 3-Cholangiography either PTC or ERCP; provides the most accurate information about the cyst and its associated ductal anatomy. However these are invasive investigations with significant complication rate.

Intra-operative cholangiography is simple, safe and accurate

DIAGNOSIS 4- Computerized tomography scanning (CT); * provides clear images of the cyst and adjacent structures. * reveals associated pathology within the parenchyma of related organs. * spiral CT cholangiography enables 3D reconstruction of the biliary tree. 5- Hepatobiliary scintigraphy with T99m labelled IDA; shows the cyst and establishing that the cystic structure is an intrinsic part of the biliary tree.

DIAGNOSIS 6- Magnetic resonance imaging (MRI); MR cholangiopancreatography (MRCP) is non invasive and will produce clear images of the biliary tree. 7- Other diagnostic modalities include; * Endoscopic Ultrasonography * Angiography * Laparoscopy * Intra-operative cyst endoscopy

TREATMENT ♥ All choledochal cysts will require operative treatment. There is no role for long term observation because of the risk of gallstones, pancreatitis, cholangitis, cirrhosis and malignancy. ♥ The theoretical requirements of an ideal operation are; * To allow free hepato-enteric bile flow * To remove all cyst mucosa ( with its associated malignant potential). * To exclude any “common channel” and prevent pancreaticobiliary reflux. * To minimize the subsequent risk of cholangitis.

PREPARATION All patients will require; * FBC * coagulation profile * LFTs * full bowel preparation * systemic antibiotics prior to surgery

Surgical Options; ♠ Cyst excision and hepaticojejunostomy is the mainstay of choledochal cyst surgery.

OTHER OPTIONS ♦ External Drainage ♦ Cyst excision and hepaticoduodenostomy ♦ Mucosectomy and hepaticojejunostomy ♦ Choledechocyst-enterostomy ♦ Antireflux valves

PROGNOSIS ♥ The results of primary cyst excision and hepaticojejunostomy are very satisfactory. ♥ There are many reported series with a long-term survival rate close to 100% ♥ A number of reported series show that cyst excision and hepaticojejunostomy is almost complications free in children under 5 years of age. ♥ The incidence of complications varies between 0 and 10% it includes; * calculus formation * cholangitis * anastomotic stricture * anastomotic leakage * pancreatitis * obstruction and cholangiocarcinoma in the residual ducts