Major liver resection (partial hepatectomy) is performed to treat liver lesions or for adult-to-adult living donor liver transplantation.
Surgery complication may occur due to a poor post-operative liver function (post-operative liver failure).
Liver hemodynamics plays a role in post-operative liver failure.
Investigation with mathematical models of the impact of liver surgery on hemodynamics.
Reproduce the observed waveform changes.
Pressure and flow in the main vessels of the liver have been recorded for different resection percentages on pigs.
At the resection time, waveform changes were observed repeatedly in the pressure and flow measured in the hepatic artery
(artery entering the liver).
Pressure and flow measurements in hepatic artery at the resection time for
4 different animals, black lines indicate the resection time.
Liver receives 25% of cardiac outflow, therefore the surgery may impact the whole circulation:
development of a closed-loop model of the blood circulation.
Reproduce the observed waveform changes:
model enabled to capture wave propagation, the network of artery is modeled by systems of the one-dimensional (1D)
hyperbolic Euler equations.
Schematic representation of the 1D-0D closed-loop model for porcine blood circulation including a 3-lobe liver model.
1D blood flow is simulated in the thick lines arteries while thin lines represent the 0D model connections.
All RCR units and the liver are linked (thin arrows) to the vena cava (VC).
Simulations
75% liver resection simulation (remove 2 of the 3 main liver lobes, increasing the corresponding lobe resistances).
75% – 90% liver resection simulation (resection of a part of the remaining lobe, reducing the lobe mass
i.e. changing the lobe model parameters).
The capability of the model to represent this complex behaviour allowed us to propose possible explanations of the observed phenomenon.
The fact that changes in hepatic artery flow waveform during experiments are observed for 75% resection but not for 90% hepatectomy,
can be explained by the change in architecture in the blood vessel trees. Indeed, in the first resection,
two of the three liver lobes are removed, which leads to an important architecture change.
For the second resection, the remaining lobe mass is decreased and the vessel tree architecture does not change as much.
