Abstract
This chapter provides an overview of the surgical treatment for biliary atresia, the Hepatic Portoenterostomy or Kasai Procedure. The pathophysiology of biliary atresia is reviewed as it related to the organ systems effected. The signs and symptoms of neonatal liver failure are discussed including the development of hepatorenal and hepatopulmonary syndromes. The chapter provides an overview of the surgical aspects and anesthetic concerns related to the Kasai procedure. The chapter provides a segue into the chapter on liver transplantation.
A nine-month-old male recently adopted from abroad with a past medical history significant for biliary atresia, arrives for preoperative evaluation for the Kasai procedure.
He was recently admitted for hematemesis requiring transfusion, followed by esophagogastroduodenoscopy with sclerotherapy and variceal band ligation. His oxygen saturation is 88% on room air. Physical examination is consistent with nail bed clubbing, scleral icterus, and a distended abdomen from ascites. He has scratch marks on his skin, some with scabbing and some appearing infected.
The preoperative clinic asks for guidance in performing a preoperative evaluation.
What Is Biliary Atresia?
Biliary atresia, with an incidence between 1 in 8,000 and 1 in 18,000 live births, is the most common cause of neonatal cholestasis and the most frequent indication for liver transplantation in children. Biliary atresia is a progressive fibro-inflammatory cholangiopathy leading to a complete obliteration of the extra-hepatic bile ducts. There is a slight female predominance with a female to male ratio of 1.7:1.
What Is the Natural History of Biliary Atresia?
Biliary atresia presents as neonatal jaundice. Neonatal jaundice beyond the first two weeks of life should raise suspicion for biliary atresia as morbidity and mortality depend on the timing of surgical intervention. Biliary cirrhosis, portal hypertension, and end-stage liver disease will occur in about 50% of children by two years of age with no surgical intervention. Clinical findings may include a conjugated hyperbilirubinemia, elevated gamma-glutamyl transferase, and elevated serum liver transaminases.
Neonatal jaundice progresses to hepatic fibrosis at four to six weeks of age. From two to six months, chronic hepatic fibrosis/cirrhosis results in the changes noted later in the chapter. If untreated, end-stage liver disease requiring liver transplantation occurs.
Associated congenital anomalies include polysplenia, situs inversus, absent vena cava, malrotation, and cardiac anomalies.
What Are the Associated Pathophysiologic Issues Related to Chronic Biliary Atresia?
Biliary obstruction leads to hepatic fibrosis and eventually cirrhosis.
Hepatic failure (usually after a few months of life) results in:
Anemia secondary to liver disease
Ascites (hypoalbuminemia)
Coagulopathy: intrahepatic factor production and inability to absorb vitamin K due to lack of bile salts
Hypoxemia: reduced functional residual capacity secondary to large volume ascites
Jaundice: acholic stool and dark urine
Malnutrition: malabsorption
Portal hypertension and esophageal varices
Secondary splenomegaly
Recurrent cholangitis/sepsis
What Is a Kasai Procedure (Hepatic Portoenterostomy)?
The Kasai procedure, or a hepatic portoenterostomy, involves:
(1) Mobilization of the liver to identify the porta hepatis
(2) Excision of all extrahepatic fibrous biliary remnants at the point where the portal vein enters the hepatic parenchyma.
(3) Creation of a Roux-en-Y loop of the proximal jejunum.
(4) Anastamosis of the Roux-en-Y loop of the jejunum to the porta hepatis.
The result is a conduit for biliary drainage to exit the liver.
What Is the Timing of and Prognosis for the Kasai Procedure?
The timing of the surgical intervention affects the morbidity and mortality of children with biliary atresia. Early intervention (8–12 weeks) affords the best prognosis.
Approximately one-third of children who have undergone a Kasai procedure will require no further surgical intervention whereas the other two-thirds of children will require a liver transplantation with development of portal hypertension, ascites, malnutrition, poor growth, and recurrent cholangitis.
What Is the Cause of Hematemesis in This Case?
Portal hypertension is an elevated portal venous pressure above 10–20 mmHg causing increased resistance to portal venous inflow. The increased resistance occurs not only because of hepatic fibrosis but also because of nitric oxide deficient vasoconstriction. Esophageal variceal bleeding is the most common presentation of portal hypertension with increasing blood flow from inadequate forward portal venous inflow, causing variceal expansion and rupture.
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