A feasibility study of a novel irrigation technique for reducing intrapelvic pressure during ureterorenoscopy using conventional devices
摘要
Ureterorenoscopy (URS) is a widely accepted approach for managing upper urinary tract stones, including renal calculi measuring > 20 mm. However, an elevated intrapelvic pressure (IPP) during URS can lead to infectious and procedural complications. We developed a simple irrigation technique and evaluated its efficiency in reducing IPP during URS.
MethodsIn this technique, a 14/16-Fr ureteral access sheath (UAS) was advanced to the ureteropelvic junction or distal to the stone. A 4.7-Fr single-J ureteral stent was inserted through the UAS, with the tip placed in the renal pelvis or upper calyx. The stent enabled continuous fluid outflow and reduced the IPP. We defined this technique as the “Continuous Alternative Reduction of the intrapelvic Pressure” (CARP) system. The study comprised: (1) IPP measurements in a representative case comparing conventional URS and the CARP system, and (2) a retrospective analysis of patients treated using the CARP system between June 2020 and October 2024, excluding those with staghorn calculi.
ResultsThe CARP system significantly reduced the IPP. In the conventional URS setup, pressure exceeded 100 cmH₂O during flushing, whereas the CARP system maintained pressures below 25 cmH₂O. Overall, 34 renal and 45 ureteral stones were analyzed. The median stone burden was 20.5 mm for renal and 18.2 mm for ureteral stones. The stone-free rates were 97.1% for renal and 97.8% for ureteral stones. Postoperative fever occurred in 5.1% of the patients. No UAS-related ureteral strictures were observed.
ConclusionThis technique can be easily implemented using existing devices and has demonstrated favorable outcomes with minimal complications.