Ultrastructural study of the remnant liver after extensive hepatectomy in dogs; Especially morphological alterations of sinusoidal endothelial cells

Background/Aims: To investigate the role of sinusoidal endothelial cells in the mechanism of the remnant liver dysfunction after extensive hepatectomy , morphological alteration of sinusoidal endothelial cells and cytoprotecti ve effects of prostaglandin I2 analog were studied by ultrastructural analy sis. Methodology: Mongrel dogs (n=24) were divided into 3 groups according to th e extent of hepatectomy and the use of prostaglandin I-2 analog preoperativ ely. Group 1: 70% hepatectomy (n=8), Group 2: 84% hepatectomy (n=8), and Gr oup 3: 84% hepatectomy with administration of prostaglandin I2 analog, preo peratively (n=8). Morphology of hepatic sinusoidal endothelial cells was ex amined after hepatectomy in all cases. Results: Group 2: Enlargement of the sinusoidal endothelial fenestrations w as transitorily occurred immediately after hepatectomy, but were dramatical ly decreased in size 24h after the operation. Most sinusoidal endothelial c ells were destroyed and separated from the sinusoidal wall. Fibrin deposits and sludge were found in the Disse's space and sinusoidal lumens, resembli ng liver failure at 24h after the operation. Group 1 and 3: sinusoidal endo thelial fenestrations remained slightly enlarged at 24h after the operation , but fibrin deposits or sludge were not observed in sinusoidal lumens. Conclusions: Our data suggest that extensive hepatectomy changed the morpho logy of sinusoidal endothelial cells. Administration of prostaglandin I-2 a nalog helped maintain structural integrity of sinusoidal endothelial cells, improved hepatic microcirculation and thus served to reduce remnant liver dysfunction.