Pulsatile flow through idealized renal tubules: Fluid-structure interaction and dynamic pathologies.

Area of Science:

• Biomedical Engineering
• Nephrology
• Computational Fluid Dynamics

Background:

• Kidney tubules possess flow-sensing structures, but direct measurement of intra-tubule fluid flow is challenging.
• Understanding fluid dynamics within kidney tubules is crucial for comprehending kidney function and disease progression.

Purpose of the Study:

• To develop a multiscale biomechanical model for analyzing fluid flow and fluid-structure interactions in elastic kidney tubules under pulsatile pressure.
• To investigate the impact of varying driving frequencies and wall compliances on flow dynamics and wall strains.

Main Methods:

• A two-dimensional macroscopic mathematical model of a single, fluid-filled elastic kidney tubule (distal nephron segment) was developed.
• Finite-element analysis was employed to simulate fluid flow and determine wall strains.

Main Results:

• The model accurately predicts flow dynamics and wall strains within the elastic kidney tubule.
• Results show good agreement with existing analytical solutions, validating the model's approach.
• The study provides a foundation for incorporating elastohydrodynamic coupling in future multiscale models.

Conclusions:

• The developed model offers a robust method for analyzing biomechanics within kidney tubules.
• This work supports the exploration of 'dynamic pathology' to better understand chronic kidney diseases, including Polycystic Kidney Disease.