A 2-year-old patient with biliary atresia presents with portal hypertension, esophageal varices, and massive ascites for liver transplantation after a failed Kasai procedure.
Laboratory findings: International normalized ratio 4.2; total bilirubin 16.
Biliary atresia is the most common indication for pediatric liver transplantation. Up to 20% of patients have other congenital malformations, including splenic malformations, situs inversus, or absence of the inferior vena cava. After diagnosis in infancy, a Kasai portoenterostomy (a Roux-en-Y loop is anastomosed to exposed ductules at the surface of the porta hepatis), which corrects hyperbilirubinemia within 6 months if successful, is the standard of care. This has to be performed before 3 months of age, and the failure rate is high. Those patients develop portal fibrosis, cirrhosis, and portal hypertension. Patients may have the usual stigmata of liver failure and can be hypervolemic, hyperdynamic, and coagulopathic.
Use rapid-sequence induction for patients with a full stomach or massive ascites; use a cuffed endotracheal tube.
Arterial line and central venous access must be obtained above the diaphragm because of interruption of blood flow from the aorta and the inferior vena cava during cross-clamping.
Assess arterial blood gases, hemoglobin, and urine output hourly. Every 2 hours determine complete blood cell count, coagulation factors, and fibrinogen.
Preanhepatic phase: Prepare patient for caval cross-clamp, including optimizing hemodynamics with volume (central venous pressure should be >10) and inotropic and or vasopressor infusions, making sure patient is not acidotic or hyperkalemic (bicarbonate, furosemide, hyperventilation as needed).
Anhepatic phase: There is little caval blood flow with caval cross-clamping in patients without collaterals; therefore, it is better tolerated in patients with chronic portal hypertension. Piggyback technique preserves caval blood flow but may require a caval cross-clamp on short notice.
Postanhepatic phase: Reperfusion of the graft will lead to acidemia, hyperkalemia, and hypothermia. Prepare for unclamping with hyperventilation, give calcium and NaHCO3, and have insulin, glucose, and epinephrine available. To maintain patency of the hepatic artery, it may be necessary to start a heparin infusion. After anastomosis of the hepatic artery and portal vein, the bile duct will be anastomosed, or in patients with a prior Kasai procedure, the Roux-en-Y limb can be used for bile drainage.
Defer extubation in most patients, particularly when the abdominal wall was not closed or reexploration is planned. In patients with large grafts, abdominal compartment syndrome must be treated promptly to avoid abdominal ischemia and high airway pressures, which may lead to hemodynamic compromise. Graft-related problem in the early postoperative phase are vascular complications, biliary complications, or allograft rejection.