A biphasic model for sinusoidal liver perfusion remodeling after outflow obstruction

Area of Science:

• Biomedical Engineering
• Computational Biology
• Hepatology

Background:

• Liver resection can cause focal outflow obstruction due to hepatic vein transection.
• This obstruction can lead to further damage in the remaining liver tissue.
• The liver attempts to reestablish drainage through sinusoidal dilatation and the formation of new vascular canals.

Purpose of the Study:

• To investigate the hypothesis that blood pressure gradients are the primary drivers of sinusoidal vascular canal formation.
• To develop and validate a mechanical model simulating this vascular remodeling process.
• To understand the fluid dynamics and structural changes in reestablishing hepatic venous drainage.

Main Methods:

• Generation of a biphasic mechanical model incorporating transverse isotropic permeability and an evolutional optimization rule.
• Development of a computational framework for simulating fluid flow and vascular remodeling.
• Numerical simulation of blood flow under physiological and post-obstruction conditions.

Main Results:

• The model successfully reproduced the experimentally observed reestablishment of hepatic venous drainage.
• Formation of new vascular structures and redirection of blood flow were numerically simulated.
• Results support the hypothesis that pressure gradients are key to blood flow reorientation in sinusoids.

Conclusions:

• The study provides numerical evidence that blood pressure gradients are the main driving force for sinusoidal vascular canal formation after liver outflow obstruction.
• The developed model offers a framework for studying vascular remodeling in response to pressure changes.
• Further research is needed to explore micromechanical factors influencing sinusoid reorientation.