Abstract
Purpose: To develop a physical understanding of ureterorenoscopy irrigation, we derive mathematical models from basic physical principles and compare these predictions with the results of benchtop experiments. Mathematical modeling can be used to understand the role of inlet pressure, tip deflection, the presence of working tools, geometric properties of the instruments used, and material properties of the irrigation fluid on resulting flow rate.Materials and Methods: We develop theoretical models to describe irrigation flow in an idealized setup and compare with benchtop experiments for flow through a straight scope, a scope with a deflected tip, and a scope with a working tool inserted. The benchtop experiments were performed using Boston Scientific LithoVue ureteroscope and a variety of Boston Scientific working tools. Standard ureteroscope working channels have circular cross sections, but using theoretical models we investigate whether modifications to the cross-sectional geometry can enhance flow rates.Results: The theoretical flow predictions are confirmed by experimental results. Tip deflection is shown to have a negligible effect on flow rate, but the presence of working tools decreases flow significantly (for a fixed driving pressure). Flow rate is predicted to improve when tools are placed at the edge of the channel, rather than the center, and modifying the cross-sectional shape from a circle to an ellipse can further increase flow rate.Conclusions: A mathematical framework is formulated and shown to accurately predict the properties of ureteroscope irrigation flow. The theoretical approach has significant potential in quantifying irrigation flow and improving ureteroscope design.
Highlights
Flexible ureterorenoscopy provides a minimally invasive treatment for the destruction and removal of kidney stones
The details of irrigation flow during ureteroscopy, its impact on intrarenal pressure and stone visualization and movement, are hard to determine in a clinical setting
Mathematical modeling can improve the design of endourologic tools by providing quantitative predictions of irrigation flow and intrarenal pressure
Summary
Flexible ureterorenoscopy provides a minimally invasive treatment for the destruction and removal of kidney stones. The procedure is performed by passing auxiliary working tools (e.g., laser fibers and baskets) through the working channel of a ureteroscope, and utilizing the actively deflectable tip. Good intrarenal views are obtained by flowing irrigation fluid (saline) through the scope to create a working space within the kidney and to clear this region of debris from stone fragmentation or blood. There are several different ways that urologists deliver and drain the irrigation fluid, but a typical approach is to connect a bag of saline to the scope inlet via irrigation tubing. The flow is complicated by working tools of varying sizes inserted into the channel of the ureteroscope, and there is no systematic procedure for varying the flow or quantifying the relationship between flow and intrarenal pressure
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
