A Multiscale-Multiphysics Framework for Modeling Organ-scale Liver Regrowth

TL;DR

This paper introduces a comprehensive multiscale, multiphysics modeling framework for simulating liver regrowth after partial resection, integrating perfusion, poroelastic growth, and local flow dynamics to match clinical observations.

Contribution

The framework combines synthetic vascular modeling, homogenized flow, and growth equations to accurately predict liver regeneration and local perfusion changes.

Findings

Model captures hyperperfusion after resection.

Predicts reduction of hyperperfusion to homeostasis.

Replicates local hypoperfusion near orphan vessels.

Abstract

We present a framework for modeling liver regrowth on the organ scale that is based on three components: (1) a multiscale perfusion model that combines synthetic vascular tree generation with a multi-compartment homogenized flow model, including a homogenization procedure to obtain effective parameters; (2) a poroelastic finite growth model that acts on all compartments and the synthetic vascular tree structure; (3) an evolution equation for the local volumetric growth factor, driven by the homogenized flow rate into the microcirculation as a measure of local hyperperfusion and well-suited for calibration with available data. We apply our modeling framework to a prototypical benchmark and a full-scale patient-specific liver, for which we assume a common surgical cut. Our simulation results demonstrate that our model represents hyperperfusion as a consequence of partial resection and accounts for its reduction towards a homeostatic perfusion state, exhibiting overall regrowth dynamics that correspond well with clinical observations. In addition, our results show that our model also captures local hypoperfusion in the vicinity of orphan vessels, a key requirement for the prediction of ischemia or the preoperative identification of suitable cut patterns.