In chronic human schistosomiasis mansoni, the entire hepatic lobule is involved. The hepatovascular barrier is modified and shows hepatic sinusoids with hypertrophy and stratification of endothelium, basement membrane-like deposits, perisinusoidal fibrosis, diminution of hepatocellular microvilli and hepatocellular clasmatosis into the sinusoidal circulation. This transformation of an open circulation to a partly closed one may decrease the blood hepatocyte exchanges in schistosomiasis mansoni.