Introduction: Acute liver failure (ALF) is associated with significant mortality in pediatric patients. Auxiliary partial orthotopic liver transplantation (APOLT) represents a therapeutic alternative in selected patients with ALF who retain the potential for native liver regeneration.

Case Report: A four-year-old boy presented with ALF secondary to paracetamol intoxication (166 mg/kg/day for 72 hours). At admission, he showed metabolic acidosis (pH 7.07), hyperammonemia (239 µmol/L), severe hypertransaminasemia (AST 14,320 IU/L; ALT 4,992 IU/L), coagulopathy (INR 3.8), grade III/IV hepatic encephalopathy, and acute kidney injury (creatinine 0.81 mg/dL), with rapid deterioration despite standard conservative management.

APOLT was performed 48 hours after admission using a donation after circulatory death (DCD) donor. An ex-situ liver split was carried out under hypothermic oxygenated perfusion (HOPE), implanting segments II–III–IV (graft-to-recipient weight ratio 1.78%). The right liver graft was successfully transplanted into an adult recipient. An extended left hepatectomy was performed, preserving segments VI–VII, along with a temporary portocaval shunt. The graft was implanted orthotopically with portal-to-portal anastomosis, recipient left hepatic vein anastomosed to the graft middle and left hepatic veins, common hepatic artery to recipient splenic artery, and Roux-en-Y biliary reconstruction.

Postoperative complications included a biliary leak requiring surgical repair and acute pancreatitis related to ALF. One month after transplantation, the patient showed normal hepatic, renal, and neurological function, with 65% recovery of native liver parenchyma. Progressive immunosuppression withdrawal and auxiliary graft removal are planned.

Conclusion: DCD donation with normothermic regional perfusion followed by split-HOPE represents an alternative organ source that enables auxiliary liver transplantation in critically ill pediatric patients with acute liver failure.