Study on the temperature changes around calculi in needle perc nephroscopy holmium laser lithotripsy / 中华泌尿外科杂志

ABSTRACT

Objective:To investigate the characteristics of local temperature changes around the stones during needle perc nephroscopy holmium laser lithotripsy.Methods:In vitro, Choosing a hard-plastic kidney model (the same size as the human kidney), and polishing the monohydrate calcium oxalate stones collected clinically into a round shape with a diameter of about 1 cm. Pushing the stone into the renal pelvis from the broken end of the renal pelvis and ureter junction of the kidney model to form a kidney stone model. The experiment operation was performed by the same senior doctor with needle perc nephroscopy holmium laser lithotripsy. The temperature recorder probe was placed 5 mm around the stones in the renal pelvis. The laser power were selected as 4 W and 8 W, and the perfusion rate were 0, 25 ml/ min, 50 ml/min and 100 ml/min, the pulse width modes are divided into short pulse width and long pulse width. The fifth-generation EMS laser device was selected for the laser equipment. The temperature changes were recorded around the stone in real time. The test was repeated 3 times under each condition. The temperature change value is the temperature difference between the end of the experiment and the beginning. The characteristics and differences of the temperature around the nephrolithiasis treated by needle perc nephroscopy were compared.Results:The experiments of each group were successfully completed. When the holmium laser power was 4 W and the perfusion rate was 0, 25, 50 and 100 ml/min, there was no statistically significant difference in the temperature around the lithotripsy between long pulse width and short pulse width [(3.40±0.30) ℃ vs. (2.97±0.15)℃, (1.20±0.30) ℃ vs. (1.17±0.21)℃, (0.77±0.21) ℃ vs. (0.53±0.15)℃, (0.60±0.10) ℃ vs. (0.47±0.06)℃, all P >0.05]. When the holmium laser power was 8 W and the perfusion speed was 0, 25, and 50 ml/min, the difference in temperature around the lithotripsy stones between long pulse width and short pulse width was statistically significant [(8.63±0.06) ℃ vs. (5.97± 0.25)℃, (2.63±0.06)℃ vs. (1.77±0.25)℃, (2.07±0.31)℃ vs. (0.97±0.06)℃; P<0.05]. There was no significant difference when the perfusion rate was 100 ml/min [(0.47±0.06) ℃ vs. (0.67±0.12) ℃, P>0.05]. In the long pulse width mode, when the perfusion speed was 0, 25, and 50 ml/min, there was statistical difference in the temperature change around the stone with 4 W and 8 W holmium laser power ( P<0.05); when the perfusion rate was 100 ml/min, the difference was not statistically significant ( P>0.05). Conclusions:In needle perc nephroscopy holmium laser lithotripsy, compared with low holmium laser power and short pulse width mode, high holmium laser power and long pulse width can significantly increase the surrounding temperature of the stone at the perfusion rate of 0, 25 ml/min, and 50 ml/min. However, regardless of the mode of the pulse width, while the lithotripsy power ≤8 W, and the perfusion rate ≥25 ml/min, the temperature around the stone does not change significantly during the lithotripsy. This type of operation is safe and reliable.