Kasai Procedure

Kasai procedure (portoenterostomy) is a surgical procedure to treat biliary atresia in newborns. It envolves mobilizing the liver to access the atretic bile ducts at the porta hepatis, preparing a jejunum Roeux en Y loop, anastomosis of the loop in the porta hepatis. This corrects the obliterative cholangiopathy, leading to proper drainage of bile.

Biliary atresia

Biliary atresia is a congenital malformation of the biliary tree, causing the occlusion of the extra hepatic bile duct. It is marked by an increase of conjugated bilirubin, resulting in jaundice, pale stools, dark urine. Coagulopathy, failure to thrive, hepatosplenomegaly and ascites are also common presentations. In the first few months of life, liver function is generally preserved, mantaining normal levels of albumin and prothrombin.

As the disease progresses if left untreated, cholestasis, hepatic fibrosis, cirrhosis, portal hypertension and liver failure can develop.

Medical management consists of antibiotic therapy (prevention of cholangitis), nutritional support (fat soluble vitamin supplementation), and improvement of bile flow (ursodeoxycholic acid and steroids - controversial). Surgical management includes portoenterostomy and liver transplantation.

Over 80% of the patients with a sucessful Kasai procedure are likely to survive more than 10 years with their native liver. However, all children will develop portal fibrosis, cirrhosis and portal hypertension to a greater or lesser extent, even if surgery is successful. Recurrent cholangitis is a risk factor for progression of disease. In these patients, combined management with liver transplantation can be beneficial.

Anesthesia considerations for Kasai procedure

Monitoring:

• ECG, pulse oximeter, noninvasive blood pressure and temperature
• Ventilation should be controlled and end tidal volumes monitored
• An arterial cannula should only be considered in procedures of long duration and in selected situations likely to cause anticipated circulatory impairment: total liver vascular occlusion, repeat surgery, combined organ resection, and surgery conducted on tumours >10 cm in size or in connection with the vena cava

Antibiotic prophylaxis:

• Intraoperative antibiotic prophylaxis must be administered to prevent translocation of intestinal enterobacteria to the systemic circulation

Fluids:

• Crystalloid solutions must contain dextrose to prevent hypoglycemia
• Blood sugar testing should be done intraoperatively (at least after induction and at end of surgery)
• Blood loss is generally uncommon, but if loss is over 10% of estimated blood volume, warm blood should be given
• Ascitis is also uncommon, but if present, albumin 4.5% in 0.9% saline should be used

Inhalational agent:

• Halothane should be avoided (associated with greater incidence of hepatitis and decrease in splanchnic and hepatic blood flow)
• Nitrous oxide should be avoided to prevent abdominal distension

Hypothermia prevention:

• Very common due to large surface to volume ratio and lack of insulation
• Prevent by keeping OR temperature higher than normal, warming fluids and cleaning solutions, and hot air blowers

Postoperative pain management:

• Systemic opioids (morphine infusion rate of 0.5-2 ml/h to a max of 1 mg/kg/day) - caution with respiratory depression in extubated children
• Epidurals (decrease systemic opioid use, need for postoperative mechanical ventilation, and days of hospital stay)
• Avoid NSAIDs due to worsening of pre existing renal disease

Relevant Article Depot:

Benefit of epidural analgesia for postoperative pain control after a Kasai Portoenterostomy: A ten-year retrospective cohort study