What are the operative steps of a Kasai procedure for biliary atresia?

Operative Steps of the Kasai Procedure for Biliary Atresia

The Kasai portoenterostomy is the primary surgical treatment for biliary atresia that can achieve long-term survival with the native liver by restoring bile flow through the removal of obliterated extrahepatic bile ducts and creating a hepatoportoenterostomy. 1

Preoperative Considerations

• Optimal timing: Procedure should be performed before 8-10 weeks of age for best outcomes
• Poor prognostic indicators: Vitamin K nonresponsive coagulopathy, hypoalbuminemia, advanced cirrhosis, ascites, portal hypertension, and poor nutritional status 1

Essential Operative Steps

1. Exposure and Initial Assessment

• Right subcostal or transverse upper abdominal incision
• Thorough examination of the liver and extrahepatic biliary system
• Intraoperative cholangiogram to confirm biliary atresia diagnosis if not previously established

2. Mobilization of the Porta Hepatis

• Careful dissection of the hepatoduodenal ligament
• Identification of the fibrous remnant of the extrahepatic bile ducts

3. Exposing the Proximal Bile Duct Remnants

• Approach through hilar plate: Dissection along the posterior edge of liver segment IVb along the hilar transverse groove 1
• Approach through upper portion of hepatic portal: If severe scarring prevents clear dissection, dissect deeply into liver parenchyma until confluent with the hepatic duct 1
• Follow the principle of "bile duct is three rather than two" to avoid missing the right posterior hepatic duct 1

4. Excision of the Fibrous Remnant

• Complete excision of the fibrous remnant of the extrahepatic bile ducts
• Transection at the level of the porta hepatis to expose microscopic biliary ductules
• Careful preservation of the portal vein and hepatic artery

5. Preparation of the Roux-en-Y Limb

• Creation of a 40-45 cm Roux-en-Y jejunal limb
• Jejunojejunostomy to restore intestinal continuity
• Passage of the Roux limb through the transverse mesocolon (retrocolic)

6. Hepatoportoenterostomy

• Direct anastomosis of the transected porta hepatis to the Roux limb
• Ensure wide anastomosis to maximize bile drainage
• Meticulous suturing to create a watertight anastomosis between the porta hepatis and the jejunal limb

7. Anti-reflux Measures

• Creation of an anti-reflux valve or stoma to prevent ascending cholangitis, which is a major complication 2
• Some surgeons create a separate stoma to decompress the Roux limb temporarily

Postoperative Management

• Prophylactic antibiotics to prevent cholangitis (trimethoprim/sulfamethoxazole or neomycin) 1
• Ursodeoxycholic acid to promote bile flow 1, 3
• Consider steroid therapy (though evidence for benefit is lacking) 3
• Close monitoring for complications, especially ascending cholangitis

Outcomes and Prognosis

• Clearance of jaundice can be achieved in 50-60% of infants 3
• 10-year native liver survival rates of approximately 45% 3
• Success is rarely achieved in patients older than 12 weeks 2
• Approximately 25-35% of patients survive more than 10 years without liver transplantation 4

Complications to Monitor

• Ascending cholangitis (most common and serious complication)
• Progressive fibrosis and cirrhosis
• Portal hypertension
• Failure to thrive
• Need for eventual liver transplantation

Laparoscopic Approach Considerations

The laparoscopic Kasai procedure is technically challenging but may be considered by experienced pediatric laparoscopic surgeons. Studies show comparable outcomes to open surgery in terms of jaundice clearance rate, episodes of cholangitis, and 2-year native liver survival rate, though operative times are longer 5.