Regulation of hepatic microcirculation in stepwise liver resection

Background : After liver resection a small-for-size syndrome may result from the reduction of liver volume and additional liver damage caused by hepatic hyperperfusion. Therefore the influence of the extent of liver resection on liver perfusion is investigated. Material and methods : A stepwise liver resection (removal of 30%, 70%, 90%, 95% and 97% of the liver) was performed under inhalation anaesthesia with isoflurane in 6male Lewis rats. Besides systemic arterial and venous blood pressure the portal pressure and flow was measured and the sinusoidal perfusion was visualized. Sinusoidal diameter, intersinusoidal diameter and functional capillary density were determined. Results and conclusions : A decrease in the portal flow but an increase in the portal pressure was observed. Sinusoidal diameter showed a steady but low increase when up to 70% of the liver was removed but a high increase after 90% or more of the liver was resected. This indicates a decompensation of a regulatory mecha- nism of sinusoidal perfusion. (Acta gastroenterol. belg., 2007, 70, 345-351).