Kink, flow and retention properties of urinary catheters part 2: novel design.

Research has shown that all the current designs of urinary catheters based on natural latex or silicone rubber are susceptible to the major problems associated with their use--infection, encrustation and blockage. Research, to date, has focussed on the biological aspects of these complications; little research has been directed towards the contribution of the design or materials used in the manufacture of the catheters. The aim of the current study was to evaluate a totally new concept in catheter design based on nylon braid encased in a polyurethane matrix. Novel prototypes were tested using a range of established protocols to assess their flow properties, resistance to kinking and retention properties. The results were compared to those for the conventional latex and silicone based catheters currently in clinical use. The indications were that the new designs had superior flow properties and equivalent retention properties to the all-silicone catheters. Following further modification they also had superior resistance to kinking.