S5488 Atypical Presentation of Portal Vein Stenosis: Diagnosis 13 Years Post-Liver Transplantation

Introduction: Portal vein stenosis (PVS) is a rare but recognized complication after liver transplantation (LT), potentially resulting in non-cirrhotic portal hypertension (HTN) and, in severe cases, graft failure. Doppler ultrasound (US) is the first-line imaging modality and highly sensitive for PVS. We report an unusual case of severe, late-onset PVS, diagnosed 13 years post-LT, which was missed on Doppler US and later identified via magnetic resonance imaging (MRI). Case Description/Methods: A 53-year-old woman with a history of hepatitis C and alcoholic cirrhosis underwent LT in 2011 from a brain-dead donor. During her 2019 follow-up, US showed a nodular liver, inconsistent with non-invasive fibrosis testing that indicated F1-F2 fibrosis. Annual Doppler US suggested cirrhosis but remained stable. Esophagogastroduodenoscopy (EGD) revealed grade 1 esophageal varices (EV). Laboratory testing showed persistently mild alkaline phosphatase (ALP) elevation (∼130 U/L), with aspartate aminotransferase and alanine aminotransferase mildly elevated at 28 U/L and 42 U/L, respectively. Mild thrombocytopenia was noted at 141,000/μL. Due to the nonspecific alkaline phosphatase elevation and imaging-lab discrepancies, MRI with and without contrast, and magnetic resonance cholangiopancreatography (MRCP) was performed. These revealed subtle cirrhotic features and significant PVS at the LT anastomosis. A diagnosis of non-cirrhotic portal HTN secondary to PVS was made. Interventional Radiology performed balloon angioplasty and a transjugular liver biopsy, which showed no steatosis, fibrosis, rejection, or active injury. A repeat EGD 2 months later showed complete resolution of EV. Discussion: This case illustrates a rare instance of PVS as a cause of prehepatic portal HTN emerging 13 years post-LT. The patient’s clinic status improved following angioplasty, demonstrated by EV resolution. This underscores the importance of recognizing delayed-onset vascular complications after LT. While Doppler US is a valuable first-line tool, its limitations may delay diagnosis. In patients with unexplained portal HTN and persistent liver abnormalities, cross-sectional imaging should be considered to avoid missed vascular pathology.