Assessment of intrarenal temperature dynamics when using holmium and thulium: YAG lasers in an ex vivo porcine kidney model.

AIM: To measure the temperature dynamics at the renal surface and within the urinary tract when using Ho:YAG and Tm:YAG lasers for tissue ablation. MATERIALS AND METHODS: Porcine kidneys were used. Both types of lasers with different configurations and fiber sizes were used through a flexible ureteroscope. The temperature at the renal surface was recorded using a thermal camera while the intrarenal temperature was measured using two thermal probes, the first one at the ureteropelvic junction and the second one at the calyx used for lasering. Temperature was determined at 0.5-1-3-5 and 10 min. RESULTS: Recordings at the ureteropelvic junction and calyx revealed significant increases when using Tm:YAG with the 273 µm (10 W to 50 W) (p ≤ 0.02) and 550 µm (10 W) fiber (p = 0.04). With Ho:YAG there was a significant increase when using 273 µm (at 10 W and 20 W) (p ≤ 0.03) and 365 µm (10 W) fibers (p = 0.04). Regarding fiber size there was a significant difference when using Tm:YAG (at 20 W and 40 W) (p < 0.05). The thermal camera recorded a mean increase of 8 °C in the UPJ while the remaining areas of the kidney did not undergo significant changes. CONCLUSIONS: Temperature changes were greater when using the Ho:YAG laser with respect to Tm:YAG at similar power settings for tissue ablation. The greatest temperature increase was recorded at the UPJ from where the heat dissipated throughout the kidney.

Evaluación de la dinámica de la temperatura intrarrenal con el uso de láseres holmio y tulio YAG en un modelo exvivo de riñón porcino / Assessment of intrarenal temperature dynamics when using holmium and thulium: YAG lasers in an ex vivo porcine kidney model

Objetivo Medir la dinámica de la temperatura en la superficie renal y dentro de la vía urinaria al usar los láseres Ho:YAG y Tm:YAG para la ablación tisular. Materiales y métodos Se utilizaron riñones porcinos. Ambos tipos de láseres con diferentes configuraciones y tamaños de fibras se usaron a través de un ureteroscopio flexible. La temperatura en la superficie renal fue registrada mediante una cámara termográfica mientras que la intrarrenal fue medida a través de dos termómetros, el primero en la unión pieloureteral y el segundo en el cáliz elegido para el uso del láser. La temperatura fue determinada a los 0,5-1-3-5 y 10 minutos. Resultado Los registros en la unión pieloureteral y en el cáliz revelaron incrementos significativos al usar el Tm:YAG con la fibra de 273μm (10W a 50W) (p≤0,02) y de 550μm (10W) (p=0,04). Con el Ho:YAG se registró un incremento significativo al usar fibras de 273μm (a 10W y 20W) (p≤0,03) y de 365μm (10W) (p=0,04). Respecto al tamaño de las fibras, hubo una diferencia significativa al usar el Tm:YAG (a 20W y 40W) (p<0,05). La cámara termográfica registró un incremento medio de 8°C en la unión pieloureteral mientras que el resto del riñón no sufrió cambios significativos. Conclusione Los cambios de temperatura fueron mayores al usar el láser Ho:YAG respecto al Tm:YAG a configuraciones de poder similares para la ablación tisular. El mayor incremento de temperatura fue registrado en la unión pieloureteral desde donde el calor se disipaba al resto del riñón (AU)

Aim To measure the temperature dynamics at the renal surface and within the urinary tract when using Ho:YAG and Tm:YAG lasers for tissue ablation. Materials and methods Porcine kidneys were used. Both types of lasers with different configurations and fiber sizes were used through a flexible ureteroscope. The temperature at the renal surface was recorded using a thermal camera while the intrarenal temperature was measured using two thermal probes, the first one at the ureteropelvic junction and the second one at the calyx used for lasering. Temperature was determined at 0.5-1-3-5 and 10minutes. Results Recordings at the ureteropelvic junction and calyx revealed significant increases when using Tm:YAG with the 273μm (10W to 50W) (p≤0.02) and 550μm (10W) fiber (p=0.04). With Ho:YAG there was a significant increase when using 273μm (at 10W and 20W) (p≤0.03) and 365μm (10W) fibers (p=0.04). Regarding fiber size there was a significant difference when using Tm:YAG (at 20W and 40W) (p<0.05). The thermal camera recorded a mean increase of 8°C in the UPJ while the remaining areas of the kidney did not undergo significant changes. Conclusions Temperature changes were greater when using the Ho:YAG laser with respect to Tm:YAG at similar power settings for tissue ablation. The greatest temperature increase was recorded at the UPJ from where the heat dissipated throughout the kidney (AU)