Yusuke Suto^1,, Akira Umemura¹, Hiroyuki Nitta¹, Takeshi Shiohata², Seiya Tagane³, Naoki Yanagawa⁴, Masao Nishiya⁴, Ayaka Sato⁴, Akira Sasaki¹

We report the case of a 12-year-old boy with extrahepatic portal vein obstruction (EHPVO) complicated by idiopathic portal hypertension (IPH) who underwent living-donor liver transplantation (LDLT) and second-stage splenectomy. He presented with tarry stools, severe fatigue, and anemia. Computed tomography (CT) revealed EHPVO with cavernous transformation, and endoscopy revealed gastroesophageal varices with red signs. Brain magnetic resonance imaging and spectroscopy revealed portal systemic shunt encephalopathy, and liver biopsy confirmed IPH. LDLT was performed using his father’s right lobe graft, with resection of the cavernous transformation and portal vein reconstruction. His postoperative course was uneventful, and he was discharged on day 54. Pancytopenia and splenomegaly persisted, so a second-stage splenectomy was performed. Five years after transplantation, he remains well without graft complications or recurrent portal hypertension. The Rex shunt is a common surgical strategy for EHPVO, although IPH can limit its effectiveness. LDLT is a practical treatment option for EHPVO complicated by IPH

extrahepatic portal vein obstruction, idiopathic portal hypertension, living-donor liver transplantation, splenectomy, portosystemic encephalopathy, non-cirrhotic portal hypertension