Development and initial testing of valves opened by Valsalva (abdominal straining): Proof of principle for urinary catheters or male urethra

We hypothesised that raising the abdominal pressure could provide a non-manual approach to opening urinary valve, with potential application for indwelling catheters or an intraurethral device. The ‘Vysera’ valve remains closed during short high amplitude spikes but opens when pre-defined low-amplitude is maintained pre-specified duration, allowing sustained straining achieve voluntary opening. was subjected in vitro performance and microbiological tests. Parameters specification were selected by review of large urodynamic database nominal 75 cmH2O ＋/−15 (range 60–90 cmH2O) refined using early clinical results. Valve housings designed end Foley catheter, male post-prostatectomy placement. Preliminary evaluation undertaken both designs, incorporating qualitative feedback. In testing catheter demonstrated only minimal encrustation. On catheter-sited six seven patients (86%) able open intentionally straining. When inactive, none experienced leakage (7/7 = 100%), while five (71%) leaked they coughed. device successfully placed image intensifier guidance under general anaesthetic nine patients. Three used device; initial resolved as mobilised. However, contrast difficult tolerate even few hours. Removal performed local anaesthesia flexible cystoscope stent grasper. conclude storage bladder emptying strain-activated are feasible intra-urethral parameters need be matched individual For device, additional development needed improve housing performance.