ABSTRACT
【Objective】 To investigate the effects of 450 nm diode blue laser on the morphological changes and thermal damage of renal pelvis under different conditions. 【Methods】 An ex vivo study was conducted on a fresh porcine pelvis model (7 cm×5 cm×3 cm). The laser fiber was fixed on the mechanical arm perpendicular to the renal pelvis tissue, and the distance between them was 1-2 mm. The renal pelvis tissue was incised at a speed of 1-2 mm/s and power of 5-30 W. After the incised tissue was fixed in formalin (4%), the morphology, depth, width and coagulation thickness were observed with naked eyes and a microscope. 【Results】 The different powers had different vaporization and incision effects. When the operating distance was 2 mm, the speed was 2 mm/s and power was 5 W, the vaporization depth, width and coagulation thickness were approximately 0 9 mm, 0.25 mm and 0.35 mm, respectively. With the increase of power, the vaporization width and depth increased, and the coagulation thickness was 0.35-0.50 mm. When the power was more than 10 W, the renal pelvis tissue was easily penetrated. When the laser power was 20 W, the section of the renal pelvis showed an irregular shape of vaporization. When the operating distance was 1 mm, the whole renal pelvis tissue was easily vaporized. When it was 2 mm, a wide and safe energy treatment window was produced. 【Conclusion】 The 450 nm diode blue laser can vaporize and incise renal pelvis tissue safely and effectively, with high precision and little thermal damage. It is expected to be a new surgical tool in the treatment of renal pelvis lesions.
ABSTRACT
【Objective】 To compare the efficacy and safety of blue laser en bloc enucleation and traditional plasmakinetic electrocautery in the treatment of non-muscle invasive bladder cancer (NMIBC). 【Methods】 A total of 50 NMIBC patients treated in our hospital during Oct.2018 and Dec.2019 were enrolled. A randomized, incomplete blinding, parallel control design and non-inferior test method was adopted. The control group (electrocautery group) used plasmakinetic electrocautery for transurethral resection, and the experimental group (blue laser group) used semiconductor blue laser for transurethral en bloc enucleation. The effective resection rate, operation time, postoperative catheter indwelling time, length of hospital stay, perioperative hemoglobin changes and obturator nerve reflex were compared. 【Results】 There were 24 patients in the blue laser group and 26 in the electrocautery group. The effective dissection rate and hemostasis rate in both groups reached 100%. The blue laser group had slightly longer operation time than the electrocautery group (55 min vs.42 min, P=0.009), but lesser hemoglobin decrease (5.7 g/L vs. 10.4 g/L, P=0.007). There were no significant differences in urinary catheter indwelling time, length of hospital stay and reoperation rate between the two groups. The electrocautery group had 3 cases of obturator nerve reflex, while the blue laser group had none. 【Conclusion】 Compared with the traditional electrocautery, blue laser has good vaporization cutting and coagulation hemostatic effects on bladder tumor tissue, and can completely enucleate tumors in a front-firing model with less bleeding and no obturator nerve reflex, which can be used as a new, efficient, safe and easy-to-learn method for NMIBC surgery. However, its effects on postoperative recurrence rate and progression rate still need further studies.