Extrahepatic biliary atresia

Extrahepatic biliary atresia CMC Chitwan Medical college

1. Biliary Atresia Anup Shrestha CMC

2. Introduction Biliary atresia (BA) is a progressive, idiopathic, fibro- obliterative disease of the extrahepatic biliary tree that presents with biliary obstruction exclusively in the neonatal period. Overall incidence is low (approximately 1 in 10,000 to 20,000 live births ) BA is the most common indication for liver transplantation in children.

3. Japanese Association of Pediatric Surgeons classification In type I, or “distal” BA, atresia affects only the CBD, with the GB and hepatic ducts remaining patent . type IIa , in which the gallbladder and CBD are both present and patent Type IIb , in which the GB, CBD , and hepatic ducts are all obliterated type III or “complete,” : obliteration of both intrahepatic bile ducts as well as the entire extrahepatic biliary

4. D istinct clinical forms F etal-embryonic (or syndromic ): is characterized by early cholestasis , appears in the first 2 weeks of life. - In this form, the bile ducts are discontinuous at birth, and affected neonates have associated congenital defects: situs inversus , polysplenia , malrotation , intestinal atresia, and cardiac anomalies . P erinatal (or acquired ): This form is typically found in neonates and infants aged 2-8 weeks. Progressive inflammation and obliteration of the extrahepatic bile ducts occurs after birth. - This form is not associated with congenital anomalies , and infants may have a short jaundice –free interval .

5. Etiology Genetic: Recent work has identified mutations in jagged 1, a Notch signaling ligand, and the left right patterning gene Nodal Cofactor Cryptic (CFC1 ). Immunologic: Overexpression of adhesion molecules in biliary epithelium. -Aberrant expression of class I and II HLAs -Expression of Fas ligand and increased apoptosis of bile duct epithelial cells Vascular Abnormalities : impaired arterial flow may lead to necrosis and fibrous obliteration of extrahepatic bile ducts Viral : Reovirus type3, Rotavirus, Cytomegalovirus, Papillomavirus Environmental/miscellaneous- Gestational use of drugs (amphetamines, alcohol), p hytotoxins , mycotoxins , Industrial toxins, g estational diabetes, maternal age

6. Epidemiology It is most commonly observed in East Asian countries, with a reported incidence as high as 1 in 5,000 to 10,000 live births More common in females than in males Chinese infants seem to be particularly at risk

7. Clinical Features J aundice lasting longer than the first 2 weeks of life A cholic stools D ark urine Hepatomegaly V itamin K deficiency Coagulopathy Cardiac Murmurs

8. Workup Labs- LFT infants show moderate elevations in total bilirubin, which is commonly 6-12 mg/ dL . Elevated Alkaline phosphatase ( ALP ), gamma- glutamyl transpeptidase (GGTP), serum aminotransferases , serum bile acids albumin, total protein are in normal range.

9. USG A shrunken gallbladder despite fasting and lack of intrahepatic bile ducts. The presence of a hyperechogenic hilum on ultrasound, or “triangular cord sign

10. Hepatobiliary Iminodiacetic Acid (HIDA) S can L ack of bile excretion into the intestine on HIDA scan is consistent with BA. The specificity is 93% specific, and 94.6% accurate in diagnosing BA. Limitation- - infants with severe hepatitis may exhibit impaired radiotracer uptake and thus have limited excretion into the bowel . - Additionally, given the progressive nature of BA , some infants may initially demonstrate some flow of radiotracer into the duodenum with the gradual obliteration of this tract later in the disease

11. MRCP P rovide more detailed definition of the biliary tree. Findings- include incomplete visualization of the extrahepatic biliary system and periportal high-signal intensity on T2-weighted MRI scans  Sensitivity and specificity of greater than 90%

12. ERCP ERCP allows direct visualization of the extrahepatic biliary tree. It requires a general anesthetic, substantial expertise, and the availability of sufficiently small endoscopes.

13. Preoperative liver biopsy U sed method to help exclude other causes of neonatal jaundice . Findings suggestive of BA include portal or bridging fibrosis, bile duct proliferation, portal inflammation and bile duct plugs

14. Surgical Management- the Roux-en-Y HPE (Kasai procedure) First performed by Morio Kasai in 1959 In this procedure , the extrahepatic biliary tree is excised, and the fibrous portal plate at the hilum of the liver is transected and anastomosed to a Roux-en-Y limb

15. Procedure Incision – rooftop or Chevron

16. Procedure the abdomen is grossly inspected to identify any evidence of associated anomalies, such as intestinal malrotation or abnormalities of the spleen and portal vein the liver often appears cholestatic or fibrotic with a fibrotic and shrunken-appearing gallbladder. If the gallbladder is normal in appearance, is patent, the contents of the gallbladder may be aspirated to assess . If clear (“ white”) bile is aspirated, no additional maneuvers are required . If the fluid is darker appearing, it is recommended to proceed with a cholangiogram

17. Intra-op Cholangiogram Is considered gold standard for diagnosis of BA If contrast appears to freely flow into both the intrahepatic ducts as well as the duodenum, BA may be safely excluded. If a complete biliary tree is not visualized, biliary-enteric continuity must be restored

18. The peritoneum overlying the hepatoduodenal ligament is opened to allow identification of the structures in this area. Fibrous remnant of the distal common bile duct is often present here. As dissection continues proximally, the biliary remnant develops into a cone of fibrotic tissue that is located at the bifurcation of the main portal vein into its left and right branches . –most important landmark during the dissection of the portal plate and should be the goal of every dissection

19. Roux Limb Construction Proximal jejunum is identified and transected about 10 centimeters distal to the ligament of Treitz The distal end, destined for the right upper quadrant , is oversewn and the Roux limb is measured to 40 to 50 centimeters. At this location, an end-to-side jejunojejunostomy is created with interrupted absorbable sutures. The oversewn end of the Roux limb is carefully brought into the right upper quadrant via a small defect created in the avascular portion of the transverse mesocolon .

20. Portoenterostomy An end-to-end HPE is created rather than an end-to-side to avoid creating a long unused blind end as the bowel continues to grow over time.

21. Post-op care Drainage of gastric secretions with a nasogastric tube should continue for the first 48 hours, then removed NPO can be broken at 2nd or 3rd day High calorie diet – 3 to 4 gm / pg / day Drain removed at 5th P.O.D Ursodeoxycholic Acid for choleretic effect Antibiotics V itamin A, D ,E ,K supplements Methylprednisolone should be given for it’s anti-inflammatory and choleretic effects

22. Outcome 30-day postoperative mortality following HPE is low, and is estimated to be 0% to 5% Patients in whom biliary drainage is adequate develop pigmented stools with an associated downtrend in serum bilirubin levels, typically within the first 10 to 14 days after surgery . H alf of patients will continue to experience liver inflammation, fibrosis, and eventual liver failure despite an initial good response following HPE. U ltimately need liver transplantation by a mean age of 5.4 years

23. Long-term native-liver survival by age at hepatoportoenterostomy groups 1 and 2 are operative age < 6 days; group 3, 61 to 90 days ; group 4, 91 to 120 days; group 5, 121 to 150 days; group 6 , > 151 days

24. Complications Cholangitis- MC Complication - Mechanism- reflux of intestinal content - Bacterial Translocation - Impaired portal lymphatic drainage Prevention :- I nitial construction of an adequate Roux limb is fundamental -Prophylactic antibiotics - Intractable cholangitis : Liver Transplant should be considered

25. Portal Hypertension I t is estimated that as many as 30% to 70% of patients will continue to have elevated portal pressures following HPE Results in esophageal varices and ascites Half of the patient will have atleast one episode of variceal bleeding β- blockers and endoscopic interventions ( sclerotherapy or banding) as primary prophylaxis in children

26. Hepatopulmonary Syndrome characterized by hypoxia associated with chronic liver disease with evidence of intrapulmonary shunting inability of the liver to metabolize vasoactive substances may lead to abnormal shunting within the lungs, ultimately resulting in symptoms of dyspnea, platypnea , and orthodoexia No effective medical therapy Liver transplant – definitive treatment

27. Thank You