Effect of outflow resistance on intrarenal pressure at different irrigation rates during ureteroscopy: in vivo evaluation.
To maintain visualization and control temperature elevation during ureteroscopy, higher irrigation rates are necessary, but this can increase intrarenal pressure (IRP) and lead to adverse effects like sepsis. The IRP is also dependent on outflow resistance but this has not been quantitatively evaluated in a biological system. In this study, we sought to characterize the IRP as a function of irrigation rate in an in vivo porcine model at different outflow resistances. Ureteroscopy was performed in a porcine model with a 9.5 Fr prototype ureteroscope containing a pressure sensor. A modified ureteral access sheath (UAS) (11/13 Fr, 36 cm) was configured to adjust outflow resistance. IRP-irrigation rate curves were generated at four different outlet resistances representing different outflow scenarios. At lower irrigation rates, the pressure change in response to increased irrigation was gradual and non-linear, likely reflecting a "compliant" phase of the renal collecting system. Once IRP reached the range of 35-50 cm H
Marom R, Dau JJ, Hall TL, Ghani KR, Louters MM, Kim HJ, et al [Khajeh NR] Effect of outflow resistance on intrarenal pressure at different irrigation rates during ureteroscopy: in vivo evaluation. Urolithiasis. 2023 Jul 29;51(1):98. doi: 10.1007/s00240-023-01470-2. PMID: 37515665.