Most Common Causes of Portal Hypertension in Children
Portal vein thrombosis (PVT) is the most common cause of portal hypertension in children, accounting for 5-20% of all cases and up to 63% in some pediatric cohorts, followed by biliary atresia and liver cirrhosis. 1, 2
Etiology by Anatomic Classification
Portal hypertension in children is best understood by anatomic location of obstruction 3:
Prehepatic (Extrahepatic) Causes - Most Common Overall
- Portal vein thrombosis (PVT)/Extrahepatic portal vein obstruction (EHPVO): The predominant cause in children
- Risk factors include umbilical vein catheterization (73% of cases), neonatal bacterial infections (47.6%), dehydration, transfusions, and thrombophilia 4
- Cavernous transformation of the portal vein develops over months following acute thrombosis 5
- More than half of cases have no identifiable underlying disorder 6, 7
Intrahepatic Causes
- Biliary atresia: Second most common cause (18% of cases) 2
- Liver cirrhosis: Accounts for approximately 19% of pediatric cases 2
- Congenital hepatic fibrosis (CHF): Characterized by ductal plate malformation, often associated with Caroli's disease and renal cysts 8
- Non-cirrhotic portal fibrosis (NCPF): Less common in children, typically presents in second decade 8
Posthepatic Causes
- Budd-Chiari syndrome: Hepatic venous outflow tract obstruction 3
Clinical Presentation
Primary Manifestations
Children with portal hypertension typically present with gastrointestinal hemorrhage (49% as first symptom) and splenomegaly (35% as first symptom). 4, 3
Key presenting features include:
- Upper gastrointestinal bleeding from esophageal varices (present in 89% of cases) 4, 6
- Splenomegaly - often massive, causing pain and early satiety 8
- Thrombocytopenia (present in 70% of cases) and other cytopenias from hypersplenism 4, 8
- Preserved hepatic synthetic function in non-cirrhotic causes (normal transaminases, alkaline phosphatase) 5
Less Common Presentations
- Fortuitous findings on imaging (increasingly common with improved diagnostic sensitivity) 5
- Post-prandial abdominal pain or incomplete bowel obstruction from ischemic stenosis 5
- Biliary symptoms (pain, pancreatitis, cholecystitis) from portal cholangiopathy - compression of bile ducts by cavernoma collaterals 5
- Growth failure, particularly in EHPVO 8
- Firm palpable liver in congenital hepatic fibrosis 8
Diagnostic Approach
Doppler ultrasound showing splenomegaly and portosystemic collaterals is the imaging modality of choice for diagnosis in children with PVT 1. Contrast-enhanced CT and MR venography provide additional detail 1.
Important Clinical Pitfalls
HPS can occur without liver dysfunction: Hepatopulmonary syndrome develops in patients with portal vein thrombosis, cavernous transformation, and congenital hepatic fibrosis even without cirrhosis 3. Screen all children with portosystemic shunting using room air pulse oximetry in upright position 3.
Age-specific patterns: PVT is significantly associated with age >8 years (p=0.007) 2, while NCPF typically presents in the second decade 8.
Thrombophilia workup essential: Protein C, protein S, and antithrombin III levels are decreased in 92% of tested patients, with 88% having positive thrombophilia mutations 4.
Screening timeline: Start screening for portal hypertension at 6 months after PVT detection, then annually for 5 years 1. Portal hypertension may develop years after the acute thrombotic event (mean 5.7 years in some series) 1.