ABSTRACT
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.
ABSTRACT
Objective:To investigate the technical points and clinical effect of thulium fiber laser lobes-enucleation of the prostate (ThuLLEP).Methods:A total of 90 patients underwent ThuLLEP and plasmakinetic enucleation of prostate (PKEP) in our hospital from November 2018 to December 2020 were collected. The age of patients in the two groups was (67.7±6.8) years and (65.7±7.1) years, the prostate volume was 56.0 (46.0-83.5) ml and 61.0 (53.5-79.5) ml, the serum PSA was 3.6 (2.2-6.0) ng/ml and 4.4 (1.8-7.3) ng/ml, the international prostate symptom score (IPSS) was 27 (22-31) and 28 (23-30), the quality of life score (QOL) was 5 (5-6) and 5 (5-6), the maximum urinary flow rate (Q max) was (8.5±5.7) ml/s and (7.8±3.8) ml/s, the post-void residual volume (PVR) was 127 (47-250) ml and 100 (27-209) ml. The differences had no statistical significance ( P>0.05). The glands were bluntly dissected to establish the surgical capsule plane on both sides of the verumontanum after the verumontanum being located. And then the middle lobe was removed. The glands formed grooves at 12 o'clock after vaporization, which served as anatomical marker. The left and right lobes were removed step by step. Finally, tissue crushing was performed. The PKEP group was enucleated by three lobes enucleation. Perioperative indicators were compared between the two groups. Results:All the operations were completed successfully. The median operative time in ThuLLEP and PKEP groups was 60 (50-73) minutes and 75 (60-100) minutes, the postoperative bladder irrigation time was 2.8 (2.3-3.6) d and 3.8 (2.6-4.7) d, the catheter indwelling time was 4.1 (3.7-4.9) d and 4.9 (4.7-6.0) d, the postoperative hospital stay was 5 (4-6) d and 6 (5-7) d. The decreased hemoglobin was 8.0 (1.5-14.5) g/L and 15.0 (6.5-21.0) g/L. The differences had statistical significance ( P<0.05). Follow-up was performed for 6 months after surgery. The median IPSS score of the two groups was 5 (2-11) and 6 (3-9), the QOL score was 1 (1-2) and 1 (1-2) respectively, which had statistical significance compared with the preoperative parameters ( P<0.05), but no statistical significance between the two groups ( P>0.05). The ThuLLEP group had 1 case of postoperative blood transfusion, 1 case of transient urinary incontinence and 2 cases of urethral stricture. The PKEP group had 1 case of fever and blood transfusion, 3 cases of transient urinary incontinence and 3 cases of urethral stricture. Conclusions:ThuLLEP has definite clinical effect because of less bleeding, quicker recovery and fewer complications. The relatively simple operation steps are beneficial for beginners to master.