A comparison of incidences of bladder neck contracture of 80- versus 180-W GreenLight laser photoselective vaporization of benign prostatic hyperplasia

Abstract

Bladder neck contracture (BNC) after GreenLight laser photoselective vaporization (PVP) of benign prostatic hyperplasia is a common complication. In the present study, data of patients received 80 or 180 W PVP were collected. Perioperative parameters, including applied energy, irradiation time, catheter removal time, and hospital stay, were recorded. Postoperative parameters, including maximum urinary flow rate, International Prostate Symptom Score, post-void residual volume, and incidences of BNC, were recorded at 3 and 12 months after operations. Bladder neck tissues were taken at 3 months after operations for immunohistochemical staining and western blot analysis to examine the expressions of collagen I, matrix metalloproteinase-3 (MMP-3), and transforming growth factor-β (TGF-β). Sample size of patients was calculated with a power of 80 %. Chi-square test and one-way analysis of variance were performed as statistical methods. Three hundred twenty-six patients who received potassium titanyl phosphate (KTP) laser and 256 who received X-ray photoelectron spectroscopy (XPS) laser entered into the study. Perioperative parameters were comparable, except for shorter irradiation time in 180 W group (P = 0.032). Postoperative parameters were also similar, except for higher incidence of BNC in 80 W group at 3 months after operations (P = 0.022). Immunohistochemical staining and western blot analysis showed higher expressions of collagen I, MMP-3, and TGF-β in 80 W group than in 180 W group. In conclusion, 80 W GreenLight laser showed a comparable efficacy with 180-W laser in PVP but showed a higher incidence of BNC in short term, which might be the result of up-regulated fibrotic factors in bladder neck triggered by lasers.

Evaluation of transurethral GreenLight laser-selective vaporization for refractory overactive bladder in women

“…Histological staining in this study showed a decrease in the expression of selected inflammatory factors after vaporization compared to before treatment. As laser energy attenuates with distance from the center of the laser beam, laser therapy can produce a biological activity effect called photobiomodulation (PBM) in surrounding tissues ( 9 ). The anti-inflammatory effect is considered one of PBM’s most important biological effects ( 21 ).…”

“…The utilization of laser systems for PV dates back to their initial introduction in 1998, beginning with the GreenLight KTP laser (80 W) ( 8 ), progressing to the GreenLight HPS laser (120 W), and culminating in the latest iteration known as the GreenLight XPS lasers (180 W). The GreenLight laser generator emits a pulsed laser beam characterized by a wavelength of 532 nm, a pulse width ranging from 100 to 120 ns, a frequency of 13 kHz, and a laser beam area that varies between 0.2 and 0.5 mm 2 , with a specific size contingent upon the distance between the fiber tip and the tissue surface ( 9 ).…”