Partial hepatectomy hemodynamics changes: Experimental data explained by closed-loop lumped modeling.

Area of Science:

• Physiology
• Surgical Engineering
• Computational Biology

Background:

• Partial liver ablation can impair liver function, with adverse hemodynamics linked to liver failure.
• The relationship between hemodynamic changes and ablation size remains unclear.
• Understanding these changes is crucial for managing post-surgical liver function.

Purpose of the Study:

• To develop and validate a closed-loop lumped model explaining hemodynamic alterations post-partial liver ablation.
• To investigate the impact of ablation size and blood volume changes on liver hemodynamics.
• To provide a framework for understanding inter-subject variability in post-operative states.

Main Methods:

• A closed-loop lumped model simulating porcine liver hemodynamics during surgery.
• Modeling the portal venous tree with a pressure-dependent variable resistor.
• Tuning model parameters with pre-operative measurements and simulating post-operative conditions, including fluid infusion and blood loss.

Main Results:

• The model accurately captures key hemodynamic changes post-75% hepatectomy, including increased portal pressure and liver pressure loss, and decreased portal and arterial flow.
• A 75% reduction in hepatic arterial flow is explained by increased surgical resistance, not the hepatic arterial buffer response (HABR).
• The model reproduces observed post-operative states and explains inter-subject variability.

Conclusions:

• The developed closed-loop model effectively explains hemodynamic changes following partial liver ablation.
• Increased surgical resistance, not HABR, is the primary driver of reduced hepatic arterial flow.
• The model offers a adaptable framework for clinical hepatic applications and studying diverse pathologies.