Hepatic venous outflow obstruction: Three similar syndromes

Table 1 Definition, etiology and histology of VOD, BCS, and CH

	VOD	BCS	CH
Site of venous obstruction	Hepatic sinusoids and terminal venules	From hepatic veins to the superior end of IVC	Heart
Etiology	Sinusoidal endothelial injury due to HSCT, chemotherapy, abdominal radiotherapy, and pyrrolizidine alkaloids	Hepatic vein thrombosis, IVC webs, compression of hepatic veins or IVC by tumor, cyst, or abscess	Increased right atrial pressure due to CHF (CAD, cardiomyopathies, valve abnormalities), cor pulmonale (COPD, ILD, pulmonary HTN), and pericardial disease (constrictive pericarditis, pericardial tamponade)
Histology	Changes predominantly in perivenular areas	Predominantly in perivenular areas except in presence of concomitant PVT.	Predominantly in perivenular areas Sinusoidal congestion and hepatocellular necrosis
	Gaps in SEC barrier leading to subendothelial edema	Sinusoidal congestion followed by ischemic cell necrosis and bridging fibrosis between central veins	Bridging fibrosis between central veins leading to cardiac fibrosis in chronic cases
	Narrowing of central veins and sinusoids with sinusoidal congestion and hepatocellular necrosis	Caudate lobe hypertrophy, with fibrosis and atrophy in the rest of liver
	Collagen accumulation in sinusoids and veins leading to bridging fibrosis between central veins

VOD: Veno-occlusive disease, BCS: Budd-Chiari Syndrome, CH: Congestive hepatopathy, IVC: Inferior vena cava, HSCT: Hematopoietic stem cell transplantation, CHF: Congestive heart failure, CAD: Coronary artery disease, COPD: Chronic obstructive pulmonary disease, ILD: Interstitial lung disease, SEC: Sinusoidal endothelial cell, PVT: Portal vein thrombosis.