Choledochal cysts - 2

Prevalence
Race

• Persons of Asian ancestry, especially those of Japanese descent, may have a somewhat increased risk.

Sex

• Choledochal cysts are more prevalent in females. The female-to-male ratio is approximately between 3:1 and 4:1.

Presentation

• The clinical history and presentation of a patient with a choledochal cyst varies with the patient's age.

• Overt, dramatic signs and symptoms are more common in infancy, whereas manifestations are more subtle in adulthood.

• Most patients with choledochal cysts have some clinical manifestation of the disease in childhood.

•  Approximately 67% of patients with choledochal cysts have signs or symptoms related to the cyst before they are 10 years of age. 80% before adulthood.

Infants

• Infants frequently come to clinical attention with jaundice and the passage of acholic stools.

• Infants with choledochal cysts can have a palpable mass in the right upper abdominal quadrant; this may be accompanied by hepatomegaly.

Children

• Intermittent bouts of biliary obstructive symptoms or recurrent episodes of acute pancreatitis.

• May also have jaundice and a palpable mass in the right upper quadrant.

• The correct diagnosis is occasionally more difficult in children with pancreatitis.

• An analysis of biochemical laboratory values reveals elevations in amylase and lipase levels. 

Adults

• In adult patients, subclinical bile duct inflammation and biliary stasis have been ongoing for years.

•  Adults with choledochal cysts can present with hepatic abscesses, cirrhosis, recurrent pancreatitis, cholelithiasis, and portal hypertension.

• Uncommon cause of obstructive jaundice!

The most common symptom in adults is abdominal pain. Classic clinical triad of abdominal pain(70-90%), jaundice(30-50%), and a palpable right upper quadrant abdominal mass(25%) has been described in adults with choledochal cysts, although this is found in only 20-30% of patients. Cholangitis can be part of the clinical presentation in adult patients with biliary obstruction.Choledochal cysts not appearing until adulthood can be associated with a number of serious complications resulting from long-standing biliary obstruction and recurrent bouts of cholangitis.


Complications

• Cholelithiasis/choledocholithiasis

• Severe pancreatitis

• Hepatic abscesses

• Hepatic cirrhosis

• Portal hypertension/portal vein thrombosis

• Cholangitis

• 2% risk of malignancy, which may develop in any part of the biliary tree.

• Cyst rupture – biliary peritonitis

• Bleeding

 Preferred Examination

• According to Miyano and Yamataka, the preferred initial radiologic examination in the diagnostic workup of a choledochal cyst is an abdominal ultrasonography (US) scan.

•  US scanning is noninvasive and involves no radiation exposure, and its findings are sensitive and specific for the diagnosis. 

•  Uss-fusiform cyst beneath porta hepatis.

• Separate from gall bladder(c/o double GB,agenesis).

• Communication with CHD/intrahepatic ducts need to be demonstrated.

• Abrupt change of calibre at junction of dilated segment to normal ducts.

• Intra hepatic ducts may be dilated(16%) due to obstruction, but most peripheral ones do not.

Once a preliminary diagnosis is made using US scanning, other supportive studies , including abdominal computed tomography (CT) scans, magnetic resonance imaging (MRI) studies, or magnetic resonance cholangiopancreatographic (MRCP) examination is confirmatory. These studies demonstrate the cyst with more precise anatomic detail, important anatomic relationships.

• UGI studies- RUQ mass,anterior displacement of 2 nd part of duodenum,widening of c loop.

•  HIDA – may not fill with radionuclide, or late filling up to 1 hour.

Limitations of Techniques

• Its effectiveness is dependent on operator experience.

• Cysts on US images may be misinterpreted as the gallbladder or other structures.

• Decreased sensitivity in the presence of overlying bowel gas, pancreatitis, cholangitis, or other inflammatory processes.

• Differentiating a choledochal cyst from a hepatic cyst, hepatic abscess, acute fluid collection, or pancreatic pseudocyst may be difficult.

• If the diagnosis is unequivocal with US scanning, other supportive studies are usually required to adequately plan the surgical approach.

• If doubt remains despite sonographic evidence suggestive of the diagnosis, CT scanning or MRI/MRCP provides the details needed to confirm the diagnosis.

Differential Diagnoses

• Pseudocyst( Pancreatic)

•  Gallbladder duplication

• Enteric duplication cyst

• Other Problems to Be Considered

• Hepatic cystCholangiocarcinomaCholedocholithiasisCholangitis

• Biloma

• Hydronephrotic kidney

• Hepatic artery aneurysm 

 Treatments
Choledochal cysts are treated by surgical excision of the cyst with the formation of a roux-en-Y anastamosis to the biliary duct.