铥激光与钬激光碎石时升温曲线和稳态温度的差异

Comparison of temperature rise curve and steady state temperature during thulium and holmium laser lithotripsy

目的对比超脉冲铥激光与钬激光在碎石过程中升温曲线和稳态温度的差异。方法2021年11-12月采用可以进行恒温水浴、恒速灌流的水槽(体积为10 cm×10 cm×10 cm)进行实验,水槽正中为容积8 ml的模拟肾盂,将1枚体积为1 cm×1 cm×1 cm的人工结石置于模拟肾盂中进行36.5℃~37.5℃水浴,使用橡木塞封闭模拟肾盂,通过橡木塞上的孔洞将测温探头和输尿管软镜鞘置入模拟肾盂,进行软镜操作。分别使用铥激光和钬激光,在10 W(10 Hz×1.0 J;20 Hz×0.5 J)、20 W(10 Hz×2.0 J;20 Hz×1.0 J)、30 W(10 Hz×3.0 J;20 Hz×1.5 J)碎石功率下碎石,碎石过程共180 s。实验的灌注流速设置为高流速(35 ml/min)和低流速(15 ml/min)两种模式。距光纤左右各5 mm处放置测温探头,记录碎石过程中模拟肾盂中水温的变化。同一功率下,以每5秒测量的两个探头10个温度值的平均值作为该时间段的水温值。每种激光6种功率组合下共计216个时间点。比较同样参数设置下,每个时间点两种激光的温度,并绘制相应的升温曲线。采用碎石过程最后30 s内温度平均值作为稳态温度,比较相同参数设置、相同灌注流速下,两种激光达到的稳态温度。以43℃为安全阈值温度,评估两种激光的稳态温度是否超过安全阈值。结果升温曲线比较结果显示,铥激光在碎石过程77.7%(168/216)的时间点中水温高于钬激光。低流速时,铥激光在10 Hz×1.0 J[(32.43±2.19)℃与(30.99±0.90)℃,P<0.01]、10 Hz×2.0 J[(41.21±3.30)℃与(38.13±1.26)℃,P<0.01]、10 Hz×3.0 J[(49.54±2.44)℃与(44.91±0.65)℃,P<0.01]、20 Hz×0.5 J[(32.75±1.41)℃与(30.84±1.16)℃,P<0.01]、20 Hz×1.0 J[(41.67±1.76)℃与(37.51±1.25)℃,P<0.01]、20 Hz×1.5 J[(47.54±3.48)℃与(46.12±1.04)℃,P<0.01]下稳态温度显著高于钬激光。高流速时,铥激光在10 Hz×1.0 J[(28.01±0.57)℃与(26.84±0.97)℃,P<0.01]、10 Hz×2.0 J[(31.31±1.07)℃与(30.41±1.39)℃,P<0.01]、10 Hz×3.0 J[(33.29±0.70)℃与(32.25±2.55)℃,P<0.01]、20 Hz×0.5 J[(28.36±0.99)℃与(26.22±0.66)℃,P<0.01]、20 Hz×1.0 J[(30.80±2.06)℃与(30.08±0.78)℃,P=0.012]下稳态温度显著高于钬激光,在20 Hz×1.5 J[(34.54±3.08)℃与(33.93±1.49)℃,P=0.163]下与钬激光稳态温度差异无统计学意义。低流速时,铥激光在10 Hz×1.0 J、20 Hz×0.5 J下未超过安全阈值温度,钬激光在10 Hz×1.0 J、10 Hz×2.0 J、20 Hz×0.5 J和20 Hz×1.0 J下未超过安全阈值温度。高流速时,两种激光所有功率组合均未超过安全阈值温度。结论与钬激光相比,在相同参数设置和灌注流速下,铥激光的热效应更明显。相同功率下,使用铥激光碎石时应保证灌注流速快于钬激光,以免损伤组织。

Objective To compare the temperature rise curve and steady-state temperature of thulium and holmium laser in lithotripsy.Methods This study was conducted from November to December 2021.Firstly,we designed an experimental water tank(10 cm×10 cm×10 cm)that can carry out constant temperature water bath,with a 8ml simulated renal pelvis,and can carry out constant velocity perfusion in the simulated renal pelvis.A 1 cm×1 cm×1 cm cubic artificial stone was placed in the simulated renal pelvis to perform 36.5℃-37.5℃water bath.The simulated renal pelvis was closed with an oak plug,the temperature measuring probe and flexible ureteroscope were placed through the hole on the oak plug and entered into the simulated renal pelvis.Flexible ureteroscope was carried out by urologists.The lithotripsy lasted a total of 180 seconds for thulium and holmium laser respectively under different parameter settings(10 Hz×1.0 J,10 Hz×2.0 J,10 Hz×3.0 J,20 Hz×0.5 J,20 Hz×1.0 J,20 Hz×1.5 J,the corresponding gravel power is 10 W,20 W and 30 W respectively),the constant speed water pump flow rate was separate as the high flow rate group(35 ml/min)and low flow rate group(15ml/min),and leave a temperature probe 5mm around the optical fiber.Water temperature change during the lithotripsy was recorded by probes,the average of 10 temperature values of two probes measured every 5 seconds was taken as the water temperature value of this period,with a total of 216 time points in 6 parameter settings.Under the same parameter settings,the temperature of two lasers at each time point was plotted and compared to form the corresponding temperature rise curve.The average temperature in the last 30 seconds during lithotripsy in the record was used as the steady-state temperature,which of thulium and holmium laser lithotripsy was compared under the same parameter setting and the same water flow velocity.Finally,43℃was taken as the safety threshold temperature to evaluate whether the temperature of the two lasers during lithotripsy exceeds the safety threshold.Results According to the temperature rise curve,the water temperature of thulium laser during lithotripsy was higher than that of holmium laser at 77.7%(168/216)of time points.At the flow rate of 15 ml/min,thulium laser was significantly higher than that of holmium laser at 10 Hz×1.0 J[(32.43±2.19℃)vs.(30.99±0.90)℃,P<0.01],10 Hz×2.0 J[(41.21±3.30℃)vs.(38.13±1.26)℃,P<0.01],10 Hz×3.0 J[(49.54±2.44)℃vs.(44.91±0.65)℃,P<0.01],20 Hz×0.5 J[(32.75±1.41)℃ vs.(30.84±1.16)℃,P<0.01],20 Hz×1.0 J[(41.67±1.76)℃vs.(37.51±1.25)℃,P<0.01],20 Hz×1.5 J[(47.54±3.48)℃vs.(46.12±1.04)℃,P<0.01].At the flow rate of 35 ml/min,the thulium laser was significantly higher than that of holmium laser at 10 Hz×1.0 J[(28.01±0.57)℃ vs.(26.84±0.97)℃,P<0.01],10 Hz×2.0 J[(31.31±1.07)℃vs.(30.41±1.39)℃,P<0.01],10 Hz×3.0 J[(33.29±0.70)℃ vs.(32.25±2.55)℃,P<0.01],20 Hz×0.5 J[(28.36±0.99)℃vs.(26.22±0.66)℃,P<0.01],20 Hz×1.0 J[(30.80±2.06)℃ vs.(30.08±0.78)℃,P=0.012],and the steady-state temperature was not significant different between two laser at 20 Hz×1.5 J[(34.54±3.08)℃and(33.93±1.49)℃,P=0.163].In the low flow rate group,thulium laser at 10 Hz×1.0 J,10 Hz×2.0 J,20 Hz×0.5 J and 20 Hz×1.0 J does not exceed the safety threshold temperature,while in the high flow rate group,any combination of laser parameters of the two lasers does not exceed the safety threshold temperature.Conclusion Under the same laser parameter setting and flow rate,the thermal eff of thulium laser is more obvious.When using thulium laser for lithotripsy,the flow rate in the process of lithotripsy being faster than that of holmium laser with the same laser setting should be ensured to avoid tissue damage.