Choledochal Cysts

CHAPTER 24 Choledochal Cysts



Greg M. Tiao



Step 1: Surgical Anatomy



♦ A choledochal cyst (CdC) is an uncommon but correctable cause of biliary obstruction.

♦ The anatomic configurations of a CdC were first classified by Alonso-Lej and colleagues and subsequently modified by Todani and colleagues into five subtypes (Fig. 24-1).
image Type I and Type IV are the most common forms.
• The common bile duct is dilated in a fusiform fashion.

• For a type I CdC, the dilatation is confined to the common bile duct.

• The dilatation in patients with a type IV CdC either extends in continuity into the intrahepatic biliary tree or there may be a short portion of normal-caliber common hepatic duct with isolated or multifocal intrahepatic duct dilatation.

image Types II, III, and V choledochal cysts are rare variants.
• A type II CdC is a diverticulum arising from the wall of the bile duct. This abnormality is thought to occur because of a localized weakness in a segment of the common bile duct.

• A type III CdC, also known as a choledochocele, consists of a dilatation at the distal end of the common bile duct that protrudes into the lumen of the duodenum. Endoscopically, its appearance is similar to that of a ureterocele found within the bladder.

• A type V CdC, or Caroli disease, consists of multiple cystic dilatations of the intrahepatic biliary tree often with strictures between the cysts. The cysts can be confined to one lobe of the liver or found throughout the intrahepatic biliary tree.

image

Figure 24-1



Step 2: Preoperative Considerations



Presentation



♦ Classically a patient presents with abdominal pain, jaundice, and a right upper quadrant mass; however, rarely are all three present at diagnosis.

♦ Some patients are diagnosed with cholangitis when they present with Charcot triad: jaundice, fever, and right upper quadrant pain.

♦ Others have recurrent episodes of pancreatitis as a result of sludge within a CdC, which causes intermittent obstruction of the pancreatic duct.

♦ A giant CdC can spontaneously perforate. Because bile causes chemical peritonitis, these patients require urgent care.

♦ A cystic anomaly of the biliary tract can be detected prenatally.
image The differential diagnosis is a CdC or a cystic variant of biliary atresia.

image These patients require assessment of the patency of the extrahepatic biliary tract. If the biliary tract is obstructed, biliary atresia is likely. If the biliary tract is patent, a CdC is likely.


Diagnosis



♦ Laboratory studies performed in patients with a CdC are often normal. Serum conjugated and unconjugated bilirubin and hepatocellular transaminase levels are within normal limits unless the patient has cholangitis or has developed cirrhosis. In patients who present with pancreatitis, serum amylase levels may be elevated.

♦ Cross-sectional imaging of the abdomen is necessary to define the anatomic configuration of a choledochal cyst. Computerized tomography or magnetic resonance imaging should be used to define the anatomic extent of disease. Hepatobiliary scintigraphy (HIDA) scan is helpful to determine patency of the biliary tract. On occasion, endoscopic retrograde cholangiopancreatography (ERCP) or, more recently, magnetic resonance cholangiopancreatography may be helpful to define anatomy more clearly, especially in cases in which the cyst size is small.


Treatment Strategy



♦ Treatment of a CdC is essential because it will cause recurrent episodes of cholangitis and may cause the development of biliary cirrhosis or evolve into a cholangiocarcinoma. All of these patients will require surgical intervention, but the type of procedure performed varies according to the subtype of CdC diagnosed. For a patient who presents with cholangitis or acute pancreatitis, surgical intervention is delayed until the inflammatory process has resolved.


Step 3: Operative Steps



Types I and IV Choledochal Cyst



♦ A right subcostal incision is used to enter the peritoneal cavity. If necessary, the incision is extended across the midline.

♦ An intraoperative cholangiogram performed through the gallbladder is helpful to determine where the proper hepatic duct appears normal and where the pancreatic duct joins the biliary tract (Fig. 24-2).

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  3. Laparoscopic and Open Pyloromyotomy
  4. Biliary Atresia

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Jun 18, 2016 | Posted by in PEDIATRICS | Comments Off on Choledochal Cysts

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