Computational Fluid Dynamics As an Approach to Ureteroscopy Irrigation

¹Department of Chemical Engineering, University of Rochester

²University of Rochester Medical Center

This project focuses on modeling the fluids dynamics during ureteroscopy, the primary surgical treatment for kidney stones. The process consists of retrograde passage of a narrowed lighted scope (ureteroscope), under vision through the urinary channel up to the stones. Ureteroscope fluid irrigation through a channel is essential to pressurize the ureter and the kidney to secure a better vision field during lithotripsy and provide a spontaneous flow passage for kidney stone fragments to move out of the kidney.

Computational Fluid Dynamics (CFD) is a branch of mechanics that creates simulations for a variety of applications and is becoming a useful tool in medical applications to study the physiological flow patterns of fluids in the human body. The aim of this project is to utilize CFD to model and monitor the development of the fluid velocity and intrapelvic pressure during ureteroscopy irrigation. Geometries were obtained from scans of patients’ anatomy and inserted into the CFD program. The ureteroscope was placed manually into the geometry at 5 different locations to obtain representative fluid velocity and intrapelvic pressure data that will be validated with known values. Patients’ information and ureteroscope’s operating conditions are provided by the University of Rochester Medical Center so that the simulation has sufficient boundary conditions to replicate an accurate real-life procedure. The flow behavior of the saline solution within the flow domain is governed by the Navier-Stokes equations. Optimization and manipulation of the geometries allow for the creation of an accurate 3-dimensional mesh throughout the geometries where the CFD software uses finite volume methods and iterative procedures to solve the basic governing equations of fluid dynamics and generate several million data points throughout the geometry.

Through the examination of velocity and pressure profiles over time, an extensive guideline can be established to determine the safe operation time for a specific ureteroscope setting. Our objective is to gauge different patients’ specific and unique flow patterns and pressure gradients during the procedure to have a better comprehensive understanding of ureteroscope irrigation.