Choledochal malformations
Key points
1:100,000
More common in Asia (especially Japan)
F:M 4:1
First presentation: From antenatal scan to adulthood
Proposed aetiology
Weakness of the duct wall during recanalisation
Distal obstruction (mechanical and/or functional )
Pancreatobiliary maljunction (also long common channel theory or Babbitt hypothesis - 70%) - reflux of bile and pancreatic enzymes weakening and dilating walls of biliary tree
(NOT vascular-ductal interaction)
Classification
2 systems (dependent on location and stage):
Todani
Kings College
Type 1 - Extra-hepatic duct dilatation (Classic) 1a, Saccular 1b or Fusiform 1c 50-80%
Type 2 - Diverticulum 2%
Type 3 - Intra-duodenal choledochal cyst (CD) Choledochocoele 1-4%
Type 4 - Both intra-and extra-hepatic ducts dilated
Type 5 - Just intra-hepatic dilatation (Caroli DISEASE)
(If associated with hepatic fibrosis then Caroli SYNDROME)
De novo mutation in PKHD1 (6p12) - coding for fibrocystin protein - presents in adolescence
Caroli syndrome autosomal recessive in most cases
>50% Associated with cystic renal diseases eg. Medullary sponge kidney
Symptoms = Symptoms of Caroli disease + symptoms of hepatic fibrosis (portal hypertension)
7% risk of Cholangiocarcinoma
Antenatal diagnosis - 15 weeks onwards, differentials are other intra-abdominal cysts. Consider MRI
Postnatal presentation - Triad of recurrent abdominal pain, jaundice and mass 10%. Can perforate.
Other presentations: obstructive jaundice, fever, nausea, vomiting, failure to thrive, perforation, cholangitis, pancreatitis, secondary biliary cirrhosis
Complications if left untreated:
◦ Pancreatitis (acute/chronic)
◦ Lithiasis (stone formation)
◦ Rupture (intra or extra peritoneal): Any part of the cyst 7%
◦ Malignancy (cyst/gallbladder ), age related
◦ Obstructive jaundice
◦ Ascending Cholangitis (NOT sclerosing)
◦ Secondary biliary cirrhosis
◦ Rapidly progressive hepatic fibrosis (reversible with surgical repair)
◦ Portal hypertension (from cyst compression or cirrhosis and its sequelae)
Investigations
USS, MRCP
Intra-op cholangiography if above not adequate
LFTs likely normal in younger children
Obstructive jaundice in older children
Need to differentiate from cystic biliary atresia on biopsy
Management
Conservative management has no role
Surgery should be as early as possible to prevent complications
Operate within 1st year of life, ideally at 3 months
Type 1 - Excision of the cyst avoiding injury to pancreas and the duct (or mucosectomy if cyst is adherent to structures as in Lilly Procedure), cholecystectomy and Roux en-Y hepaticjejunostomy, at least 40cm retrocolic Roux loop, connected 10-20cm away from DJ flexure
Type 2 - Diverticulectomy
Type 3 - ERCP and sphincterotomy or marsupialisation
Type 4 - Deal with extra-hepatic, and do lifelong follow up, may need operation as per type 5
Type 5 - Segmentectomy or Transplant
Intra-op choledochoscopy to remove intrahepatic stones to reduce the risk of cholangitis
If perforated - put in drain and stabilise before definitive surgery
Complications
Leak/stricture
3 commonest site of post-op obstruction:
Anastomosis at common hepatic duct and roux loop
Roux loop as it passes behind the colon
Jejuno-jejunostomy site
Cholangitis
Need lifelong follow up for cholangiocarcinoma and gallbladder carcinoma - regular USS
Cancer has been reported even after the complete excision of the cyst, this risk is higher the later the cyst was operated on
Page edited by Prof. Ashok Daya Ram, Consultant Paediatric and Neonatal Surgeon, Norfolk and Norwich University Hospital, UK. November 2024
References
Hirschl, Ron, et al., editors. "Choledochal Cyst." Pediatric Surgery NaT, American Pediatric Surgical Association, 2020. Pediatric Surgery Library, www.pedsurglibrary.com/apsa/view/Pediatric-Surgery-NaT/829053/all/Choledochal_Cyst.
Miyano T, Suruga K, Chen SC. A clinicopathologic study of choledochal cyst. World J Surg. 1980;4(2):231-8. doi: 10.1007/BF02393586. PMID: 7405261.
Umar J, Kudaravalli P, Lin J, et al. Caroli Disease. [Updated 2023 Jul 31]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513307/