Liver hilus dearterialization. A histological and electron microscopical study in the dog.

Liver histological and electron microscopical changes were studied in six dogs after liver hilus dearterialization and in two dogs after sham operation. All specimens were taken in vivo. In light microscopy a marked dilatation of the sinusoids was noted 90 minutes after dearterialization. After 24 hours it was even more pronounced. The hepatocytes were shrunken. On the seventh day these alterations persisted in the central area only. None of these changes were found in the sham-operated controls. In electron microscopy rounding and swelling of the mitochondria was observed on the first day after dearterialization. On the seventh day they looked normal. Damage of the endoplasmatic reticulum was found to persist even on the seventh day. The bile canaliculi membrane was damaged after dearterialization but not after sham operation. Dilatation of the sinusoids and widening of the space of Disse was observed on the first and seventh day after dearterialization. In the controls none of these changes were seen. In both dearterialized and sham-operated dogs a transient decrease in liver glycogen was noted. In conclusion, light and electron microscopical studies demonstrated reversible ischemic changes in the liver. These correlated well with our liver pO2 measurements which indicated transient hypoxia and our biochemical studies which indicated reversible damage of the liver.