Background and objective: Bacteriuria is anticipated in long-term indwelling catheter (IDC) use, and urinary tract infection (UTI) and related issues are common. Defence mechanisms against infection are undermined by presence of a Foley catheter, and adjustments to design could influence UTI risk. Methods: We reviewed aspects of IDC and ureteric stent designs to discuss potential impact on UTI risk. Key findings and limitations: Design adaptations have focussed on reducing the sump of undrained urine, potential urinary tract trauma, and bacterial adherence. Experimental and computational studies on ureteral stents found interplay between urine flow, bacterial microcolony formation, and accumulation of encrusting particles. The most critical regions for biofilm and crystal accumulation are associated with low shear stress. The full drainage system is the functioning unit, not just the IDC in isolation. This means reliably keeping the drainage system closed, and considering whether a valve is preferred to a collection bag. Other developments may include one-way valves, obstacles to “bacterial swimming”, and ultrasound techniques. Preventing or clearing IDC blockage can exploit access via the lumen or retaining balloon. Progress in computational fluid dynamics, energy delivery and soft robotics may increase future options. Clinical data on effectiveness of IDC design features is lacking, which is partly due to reliance on proxy measures and the challenges of undertaking trials. Conclusions and clinical implications: Design changes are legitimate lines of development, but are only indirect for UTI prevention. Modifications may be advantageous, but potentially might bring problems in other ways. Education of healthcare professionals can improve UTIs, and should be prioritised.
Patient summary: Catheters to help bladder drainage can cause urinary infections, and improvements in design might reduce the risk. Several approaches are described in this review. However, proving they work is a challenge. Training professionals in key aspects of catheter care is important.