Hepatic blood flow and cardiac output after porta-caval anastomosis in the rat

Investigations were performed in rats with portacaval anastomosis (PCA) in order to measure hepatic hemodynamics and cardiac output (CO) 3, 6, 14 and 28 days after operation under pentobarbitone anesthesia using the flow fraction distribution method (131I-MAA) of CO. The latter was calculated using Vierordt's principle from blood volume (BV) (125RIHSA-dilution method) and ICG-appearance time (ICG-AT) (ear-densitometry). Even 3 days after PCA CO was increased to 38.7 +/- 5.0 (SD) ml/min/100 g b.w. (normal 23.8), due to an increase of BV from 6.3 +/- 1.4 to 7.5 +/- 0.6 ml/100 g b.w. and a decrease of ICG-AT from 3.6 +/- 0.4 to 2.8 +/- 0.5 s. Arterial hepatic flow fraction of CO increased to 8.7 +/- 2.8% (control: 5.5 +/- 2.4%). Changes could be observed up to day 28. Hepatic blood flow per g liver tended to stabilize but was still decreased at day 28: 1.5 +/- 0.6 ml/min/g liver (control: 2.0 +/- 0.3). The typical hemodynamic changes in human liver cirrhosis can be reproduced by PCA alone. They are considered to be compensatory mechanisms for a reduced portal liver blood flow, which are not found to compensate completely.