Biliary Atresia

Muhammad Haris Aslam JanjuaResident, General Surgery

SIMS/Services Hospital, Lahore

Introduction• Biliary atresia is characterized by obliteration or

discontinuity of the extrahepatic biliary system, resulting in obstruction to bile flow.

• Most common surgically treatable cause of Cholestasis in newborns

• If not corrected

–Secondary biliary cirrhosis

Embryology• The biliary system originates from the hepatic

diverticulum of the foregut at 4 weeks’ gestation.

• This differentiates into cranial and caudal components, which give rise to the intrahepatic and extrahepatic bile ducts, respectively.

GroupsIsolated Biliary Atresia Associated with situs inversus

or polysplenia/asplenia with or without other congenital anomalies

Postnatal form Fetal /embryonic form

Accounts for 65-90% of cases 10-35% of cases.

Kasai classification system

• Type I– obliteration of the common bile duct– the proximal ducts are patent

• Type II – Type IIa is atresia of the hepatic duct, with cystic bile

ducts found at the porta hepatis

– Type IIb is atresia of the cystic duct, common bile duct, and hepatic ducts

• Type III – >90% of patients– atresia occurs at porta hepatis.

• Should not be confused with intrahepatic biliary hypoplasia, – Group of distinct and surgically noncorrectable

disorders.

Variants of ductal anatomy in biliary atresia

Pathophysiology/etiology

• Multifactorial – Genetic– Inflammatory– infectious

• Infectious agents causing bile duct obliteration (H/P evidence of inflammatory lesion)– reovirus type 3– rotavirus and – cytomegalovirus (CMV)

• Other causes include– bile duct ischemia, – abnormal bile acid metabolism,– pancreaticobiliary maljunction– environmental toxins

Congenital Anomalies Associated with Biliary Atresia

Malrotation

Preduodenal portal vein

Polysplenia

Interrupted inferior vena cava

Azygous continuation

Cardiac malformations

Epidemiology • Highest in Asian populations• Biliary atresia occurs in between 1 in 10,000 and 1 in• 16,700 live births

• More common in females than in males

• Long -term survival rate for infants with biliary atresia following portoenterostomy– 47-60% at 5 years – 25-35% at 10 years

• The fetal/perinatal form is evident within the first 2 weeks of life.

• The postnatal type presents in infants aged 2-8 weeks.

Diagnosis

• History– jaundice, dark urine, and light stools.

– In most cases, acholic stools are not noted at birth but develop over the first few weeks of life.

– Appetite, growth, and weight gain may be normal during the first few weeks of life.

Physical findings• Hepatomegaly may be present early, and the

liver is often firm or hard to palpation. • Splenomegaly is common, – Enlarging spleen suggests progressive cirrhosis with

portal hypertension• In fetal/neonatal form (polysplenia/asplenia

syndrome), – midline liver may be palpated in the epigastrium .

• Cardiac murmurs associated cardiac anomalies

Imp points • Direct hyperbilirubinemia is always an abnormal

finding and may be present from birth in the fetal/embryonic form.

• Consider biliary atresia in all neonates with direct hyperbilirubinemia.

• Physiologic unconjugated hyperbilirubinemia rarely persists beyond 2 weeks.– Infants with prolonged physiologic jaundice must be

evaluated for other causes.

• A high index of suspicion is key to making a diagnosis

– because surgical treatment by age 2 months has clearly been shown to improve

• the likelihood of establishing bile flow

• prevent the development of irreversible biliary cirrhosis.

Work Up

• Labs1. Serum bilirubin (total and direct)• infants show only moderate elevations in total bilirubin,

which is commonly 6-12 mg/dL, with the direct fraction comprising 50-60% of total serum bilirubin.

2. Alkaline phosphatase (AP), 5' nucleotidase, gamma-glutamyl transpeptidase(GGTP), serum aminotransferases, serum bile acids

• 3. Serum alpha1-antitrypsin with Pi typing:• Alpha1-antitrypsin deficiency is the most common

inherited liver disease that presents with neonatal cholestasis.

• 4. Sweat chloride (Cl):– Biliary tract involvement is a well-recognized complication

of cystic fibrosis (CF)

Imaging studies

• Ultrasonography– exclude specific anomalies of the extrahepatic

biliary system, particularly choledochal cysts.

– In biliary atresia it may demonstrate absence of the gallbladder and no dilatation of the biliary tree.

– sensitivity and specificity do not exceed 80%

Gallbladder ghost triad

• gallbladder length less than 1.9 cm,

• a thin or indistinct gallbladder wall,

• an irregular and lobular contour

• 97% sensitive and 100% specific for biliary atresia.

• Hepatobiliary scintiscanning– using technetium-labeled diisopropyl iminodiacetic acid (DISIDA)

nuclear scintiscan,

– intestinal excretion of radiolabel confirms patency of the extrahepatic biliary system.

• If time allows, all jaundiced infants undergoing hepatobiliary scintigraphy should be pretreated with phenobarbital (5 mg/kg/day) for 5 days before the study.

– sensitivity of hepatobiliary scintigraphy is high (~100%). – The specificity is 93% specific, and 94.6% accurate in diagnosing

biliary atresia following pretreatment with phenobarbital

– disadvantages• reliability of the scintiscan is diminished at very high

conjugated bilirubin levels (>20 mg/dL). • 10% rate of false-positive or false-negative diagnostic

errors

• MRCP– incomplete visualization of the extrahepatic

biliary system

– sensitivity and specificity of 90% and 77%, respectively.

• Endoscopic retrograde cholangiopancreatography (ERCP)

• Percutaneous liver biopsy• most accurate nonsurgical diagnostic test• differentiate between obstructive and

hepatocellular causes of cholestasis,• with 90% sensitivity and specificity for biliary atresia

– bile ductular proliferation in the liver biopsy is considered diagnostic for biliary atresia

• Intraoperative cholangiography: – demonstrates anatomy and patency of the extrahepatic

biliary tract.

Management• Surgical intervention is the only mechanism for a – definitive diagnosis (intraoperative cholangiogram)– therapy (Kasai portoenterostomy).

• Preoperative oral supplementation with fat-soluble vitamins or an intramuscular injection of vitamin K (1 mg) should be considered.

• During the operation, the fibrotic biliary tract remnant is identified, and the patency of the biliary system is assessed

• In cases in which biliary patency is associated with ductal hypoplasia, further surgical intervention is not indicated,

• Bile may be collected to evaluate for disorders of bile acid metabolism.

• In most cases of atresia, dissection into the porta hepatis and creation of a Roux-en-Y anastomosis with a 35-cm to 40-cm retrocolic jejunal segment is the procedure of choice.

Kasai procedure

• Infant should be placed supine• Right upper abdominal incision given• LHQ is searched for spleen– Absence of the spleen or the finding of polysplenia

can alert the surgeon to the presence of important associated anomalies

• Next, the liver, biliary structures, and porta are inspected– Liver is nodular and fibrotic with greenish colour

• If Rudimentary fibrous gallbladder is noted at initial exploration and if it clearly has no lumen, – diagnosis of biliary atresia has been confirmed and

the operation can proceed with dissection of the portal plate

• If G.B is Normal then fluid in lumen of G.B is aspirated– If fluid is white proceed for portal plate dissection

– If fluid is dark or there is any doubt intraoperative cholangiogram is done

If contrast flows freely into the duodenum and intointrahepatic bile ducts, then patency of the biliary tree hasbeen established and the diagnosis of biliary atresia excluded.In this scenario, a wedge liver biopsy shouldbe performed, the cholangiogram catheter removed, thecholecystotomy closed, and the operation concluded

• 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

• The bifurcation of the portal vein should be used as a landmark in such cases where the biliary remnants and portal plate are difficult to identify.

• After portal plate dissection roux limb is constructed.

• 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.

• The side of the Roux limb is opened, and the portoenterostomy is created.

• Mesenteric defect created by construction of the Roux limb and to anchor the Roux limb to the edges of the defect in the transverse mesocolon.

• Small closed suction drain is placed near the portoenteric anastomosis, and a wedge liver biopsy is routinely performed

POSTOPERATIVE 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 .• Drain removed at 5th P.O.D• Antibiotics, a choleretic agent, fat-soluble

vitamin supplements, and an oral steroid taper is used routinely.

Postoperative Medical Regimen After Hepatic Portoenterostomy

• Ursodiol (Actigall)—10-15 mg/kg/dose BID day

• Trimethoprim-Sulfamethoxazole—2.5 mg/kg/day based on Trimethoprim component dosing

• Vitamins ADEK drops—1 mL/day

• Prednisone—2 mg/kg/day and taper over 6 weeks

Tid bits • Pigmented stools either immediately or within the first 10

to 14 days after surgery suggest successful bile flow from the liver to the intestinal tract

• Half will continue to drain bile well, with efficient clearance of jaundice and normal development. This is considered a “cure,” and liver transplantation is not necessary

• In other half liver failure will evetually develop slowly Liver transplantation

• In 15 to 30% early liver transplatation is required

When to operate

• Goal is to operate before 70 to 90 days of life. It is important to note, however, that hepatic portoenterostomy is not contraindicated after 90 days of age.

• A study of older children (100 days) revealed acceptable survival rates, supporting the use of the procedure, if possible, even in older infants

Complications • Cholangitis 33 to 60% of patients following

portoenterostomy.– Treat with I/V fluids, broad spectrumm antibiotics,

choleretic agents and steroids.

• Anastomosis failure to achieve adequate bile drainage.

• Portal hypertension occur in more than 34-76% of infants.– Eventually require liver transplant.

• Progressive liver disease .

• Hepatocellular carcinoma

• Progressive fibrosis and biliary cirrhosis develop in children who do not drain bile,– liver transplantation is the only option for long-

term survival.

Available at surgicalpresentations