Influence of manual hand pump irrigation on intrapelvic temperature during retrograde intrarenal surgery: a thermography-based in vitro study.

Abstract

Introduction: Thermal injury to kidney tissue during holmium laser lithotripsy represents a significant complication. This issue is often unavoidable due to the variability of renal conditions and the absence of techniques for real-time intrarenal temperature monitoring. The objective of this research was to evaluate influence of manual hand pump irrigation on temperature of the fluid within a pelvicalyceal model during holmium laser lithotripsy.

Material and methods: Laser lithotripsy of artificial stones was carried out in a 3D-printed model of the renal pelvicalyceal system. The irrigation system employed a continuous gravity approach (P = 60 cmH₂O), augmented by manual pumping as required. A 9.2 Fr ureteroscope was inserted into the model via a ureteral access sheath (UAS), with sizes of either 10/12 Fr or 12/14 Fr.The power settings for the lithotripsy varied between 12 and 25 W. Temperature monitoring during the procedure was conducted using thermographic methods.

Results: For all laser power settings, the temperatures recorded under gravity irrigation alone were significantly higher compared to those achieved when gravity was combined with a manual hand pump, regardless of the ureteral access sheath size. When using the hand pump system and a 12/14Fr UAS, the median temperatures in none of the laser settings exceeded 30°C. However, using a 10/12Fr UAS, the median temperatures did not exceed 35°C in any of the settings and were significantly lower compared to the use of the gravity flow system alone.

Conclusions: The employment of gravity irrigation supplemented by a manually on-demand pump in retrograde intrarenal surgery is a critical component in mitigating the risk of significant temperature elevations, leading to thermal injury to the adjacent kidney tissues. Moreover, the interquartile ranges of temperatures indicating that gravity system enhanced by an on-demand pump irrigation not only reduce the median temperature but also promote a more consistent thermal environment.