Rethinking ureteral stent design: Do more side holes improve performance?

Area of Science:

• Biomedical Engineering
• Urology
• Fluid Dynamics

Background:

• Double-J ureteral stents are crucial for maintaining urinary flow but are susceptible to encrustation, biofilm formation, and infections.
• Vesicoureteral reflux (VUR), or backward urine flow, is a significant complication increasing infection risk and kidney pressure.
• Existing stent designs have limitations in preventing these complications.

Purpose of the Study:

• To investigate the functionality of additional side holes (ASHs) at stent ends, focusing on their performance during VUR.
• To evaluate the impact of ASHs on fluid dynamics, wall shear stress (WSS), and flow pathways.
• To explore how varying ASH diameters influence stent performance and complication prevention.

Main Methods:

• Computational modeling was employed to simulate fluid dynamics within ureteral stents.
• Analysis focused on flow pathways, wall shear stress (WSS), and fluid exchange during normal flow and VUR.
• Simulations included ASHs with different diameters (0.7 mm, 1 mm, 1.2 mm).

Main Results:

• ASHs redistribute fluid exchange between the stent and ureter during VUR, altering WSS patterns.
• ASH diameter significantly impacts WSS distribution; larger diameters increase fluid exchange but decrease local mean WSS.
• Reduced local mean WSS is critical for preventing biofilm attachment.

Conclusions:

• Tailored design optimization of ASHs offers a promising approach to mitigate ureteral stent complications.
• ASHs can potentially reduce risks of infection, blockage, and kidney pressure associated with indwelling stents.
• Further research into ASH design could lead to improved patient outcomes.