Continuous monitoring of intrapelvic pressure during flexible ureteroscopy using a sensor wire: a pilot study

Purpose To evaluate the feasibility of measuring the intrapelvic pressure (IPP) during f-URS with a wire including a pressure sensor and to assess IPP profiles during the procedure. Methods Patients undergoing f-URS for stone disease were recruited. A wire with pressure sensor was placed in the renal cavities to measure IPP. For these cases, either no ureteral access sheath (UAS) or 10/12 or 12/14-Fr UASs were used according to surgeon discretion. Irrigation was ensured by a combination of a continuous pressure generator set at 80 cmH 2 O and a hand-assisted irrigation system providing on-demand forced irrigation to provide proper visibility. Pressures were monitored in real time and recorded for analysis. Results Four patients undergoing five f-URS were included. IPP monitoring was successful in all patients. Mean baseline IPP was 6 cmH 2 O. During f-URS with only the endoscope in the renal cavities and irrigation pressure set at 80 cmH 2 O without any forced irrigation, the mean IPP was 63 cmH 2 O. Mean IPP during laser lithotripsy with the use of on-demand forced irrigation was 115.3 cmH 2 O. The maximum pressure peaks recorded during this therapeutic period using forced irrigation ranged from 289.3 to 436.9 cmH 2 O. Conclusion High IPP levels may be achieved during f-URS with on-demand irrigation systems. The impact of these high pressures on the risk of complications and long-term consequences still need to be evaluated adequately. But, in this preliminary pilot study, IPP could be reliably and conveniently monitored and recorded using a wire with a digital pressure sensor.