Category: Clinical Stones: Ureteroscopy
Introduction & Objective : High intrarenal pressure during (IRP) during flexible ureteroscopy can cause significant morbidities. Measurement of IRP at baseline, with different irrigation flow, with and without ureteral access sheath (UAS) and with different laser settings in patients undergoing flexible ureteroscopy can identify factors associated with morbidities of flexible ureteroscopy.
Intra renal pressure profile was measured in 20 renal units undergoing flexible ureteroscopy for renal stone with different irrigation flow rate, using different size of UAS, with different laser settings and various flexible ureteroscopes. A 2.7 Fr pressure transducer catheter for measurement of IRP was inserted into the renal pelvis under direct vision using semirigid ureteroscope. Baseline IRP was then recorded. IRP was recorded with different irrigation flow rate, with various laser settings and with fiberoptic and digital scopes.
Mean baseline IRP was 18.2 (+/- 2.7) cmH2O. With irrigation rate of 10 ml/min visibility was good in ¾ of cases and mean IRP was 48.5 cmH2O. There was linear correlation of higher irrigation flow rate with increase in IRP. With similar irrigation flow rate, change in laser setting doesn't make significant change in IRP. Larger UAS and digital scopes were associated with lower IRP.
Irrigation flow rate should be kept minimum to ensure low IRP. Laser setting doesn’t cause any change in IRP.
Anil Shrestha– Associate Professor, National Academy of Medical Sciences, Bir Hospital, Kathmandu, Bagmati, Nepal