Choosing the optimal urethral Catheter: A computational comparison

Indwelling urinary catheters, particularly Foley catheters, are commonly used in clinical care but remain associated with several complications, including bladder tissue damage, risk of infection, poor emptying speeds and urethral trauma. Despite ongoing design innovations, objective comparisons between catheter types are limited. This study aimed to develop a computational framework to quantitatively assess and compare the performance of three urinary catheter designs (Foley, Optitip, and Flume) across metrics linked to patient outcomes. A female lower urinary tract (LUT) model was constructed using standard anatomical dimensions. Each catheter was assessed using geometrical analysis, computational fluid dynamics (CFD), and finite element analysis (FEA). Simulations were performed at two catheter positions (bladder centre and bladder neck) and under two bladder pressures (4 and 20 cmH 2 O). Quantified metrics include residual urine volume, catheter height (protrusion into the bladder), immersed surface area, wall shear stress, urine flow rate, and von Mises stress in bladder tissue. The Foley catheter consistently underperformed across all metrics, showing high residual volumes, low shear stress near the side holes, and high von Mises stress in the bladder tissue (factors linked to infection, blockage, and trauma). In contrast, the Flume and Optitip catheters demonstrated improved flow dynamics, reduced catheter height, and lower immersed surface area. This study presents a novel modelling approach to assess urinary catheter design. Findings support the clinical need to move beyond traditional Foley designs and adopt better-performing alternatives to reduce complications and improve patient safety and comfort.