Porto-sinusoidal Vascular Disease: Classification and Clinical Relevance

Area of Science:

• Hepatology
• Vascular Liver Diseases

Background:

• Non-cirrhotic portal hypertension (NCPH) presents with signs of portal hypertension (PHT) but without cirrhosis.
• Idiopathic NCPH (INCPH) lacks known risk factors or extrahepatic portal vein thrombosis, with unclear pathogenesis.
• Porto-sinusoidal vascular disease (PSVD) is a proposed syndromic entity with specific histopathological criteria for NCPH diagnosis.

Purpose of the Study:

• To review the diagnosis and treatment of INCPH/PSVD.
• To discuss the strengths and weaknesses of the new PSVD classification versus the traditional clinical diagnosis of NCPH.
• To explore the pathobiology and clinical correlates of INCPH/PSVD, particularly in an Asian context.

Main Methods:

• Review of existing literature on NCPH and PSVD.
• Analysis of the diagnostic criteria and implications of the PSVD classification.
• Discussion of clinical correlates and pathobiology in an Asian population.

Main Results:

• PSVD provides histopathological criteria (obliterative portal venopathy, nodular regenerative hyperplasia, incomplete septal fibrosis) for NCPH.
• The PSVD definition broadens diagnosis to include patients without PHT or with portal vein thrombosis (PVT).
• A key con of PSVD is the mandatory invasive liver biopsy for diagnosis, contrasting with the previous clinical diagnosis of NCPH in Asian patients.

Conclusions:

• Standardized diagnostic criteria like PSVD are valuable for comparing clinical cohorts.
• Prospective clinical validation of PSVD in global cohorts is essential to prevent misclassification of liver vascular disorders.
• The natural history of subclinical PSVD and its progression to PHT remain unknown.