AB061. Are post-operative irritative symptoms more favorable in GreenLight XPS 180W laser vaporization of the prostate compared to GreenLight KTP 80W laser vaporization of the prostate?

Background: Irritative symptoms including prolonged urgency and dysuria after GreenLight laser photoselective vaporization (PVP) of benign prostatic hyperplasia (BPH) are common complication. We aimed to compare the incidence of postoperative irritative symptoms of GreenLight XPS (GL-XPS) 180W laser system with GreenLight KTP (GL-KTP) 80W laser system for the treatment of BPH and evaluate the risk factors of irritative voiding symptoms. Methods: The data of patients, who received GL-KTP 80W PVP from July 2005 to December 2007 and GLXPS 180W PVP from January 2015 to August 2016 at our institution, were reviewed. The perioperative and postoperative parameters, including laser applied time, hospital stay, International Prostate Symptom Score (IPSS), maximum urinary flow rate (Qmax), post-void residual urine (PVR), prostate volume, prostate specific antigen and incidence of irritative symptoms were collected and compared between GL-XPS and GL-KTP groups. Results: GL-KTP 80W PVP was performed in 134 patients and XPS 180W PVP in 100 patients. Preoperative demographic data were similar in both groups. Perioperative parameters were also comparable, except for shorter laser applied time in GS-XPS 180w group. (41.2 vs. 18.5 min, P<0.01). Postoperative Qmax, PVR, IPSS of both groups were improved compared to baseline, however comparison of the postoperative parameters between GL-XPS and GL-KTP groups demonstrated significant difference, with PVR, IPSS voiding subscore and IPSS storage subscore. The incidence of irritative symptom in KTP group (41/134, 30.6%) was significantly higher than that in XPS group (14/100, 14.0%), (P<0.01). On multivariate analysis, laser applied time was independently associated with irritative voiding symptoms (OR =1.1; P=0.03). Conclusions: This is the first study that evaluated the risk factor of irritative symptoms following PVP between different laser system. The GL-XPS 180W PVP appears more favorable with reducing irritative symptoms compared to GL-KTP 80W through significantly reducing laser time.