Comment onComparison of harmful gases produced during GreenLight High-Performance System laser prostatectomy and transurethral resection of the prostate.

The authors present a comparison of harmful gases produced during GreenLight HPS laser prostatectomy operating at 120W and TURVP. Overall, their report is well written, and the method used is correct; however, one might criticize their study, because they chose to perform the 2 procedures (TURVP followed by HPS laser prostatectomy) in the same patient. Others would have chosen to create 2 distinct groups, 1 for TURVP and 1 for HPS laser prostatectomy. In the present study, precise endpoints were adopted, and the results are interesting from a scientific viewpoint and quite promising for HPS laser prostatectomy. The authors conclude that the surgical smoke produced from TURVP and HPS laser prostatectomy contains potentially harmful chemical compounds, but HPS laser prostatectomy produced significantly less chemical components than TURVP. However, harmful chemical components, including 1,3-butadiene, a human carcinogen, were still released during HPS laser prostatectomy. The authors also compared the gases generated from HPS laser prostatectomy using Urosol, an irrigation solution comprising 2.7% sorbitol and 0.54% mannitol, with the gas production using normal saline solution and concluded that Urosol produced fewer types and a smaller amount of gases than normal saline. Photoselective vaporization of the prostate involving the GreenLight KTP laser was first introduced in 1998 by Malek et al.1 Since 1998, it has evolved from the GreenLight 80-W KTP powered laser through to the latest 180-W XPS laser involving a MoXy fiber.2 The key features of the new 180-W XPS laser are faster lasing speed and higher energy application. Bachmann et al,3 from the International GreenLight Users group, recently reported a comparative analysis of the energy use and lasing times found with the 3 systems. On average, with the 80-W system, a prostate of 55 cm3 was treated with 154 kJ, with the 120-W HPS laser, a prostate size of 61 cm3 was vaporized with 251 kJ (_60%), and with the 180-W XPS laser, a 67-cm3 prostate was treated with 324 kJ.3 Therefore, the results regarding gas production are expected to change with the newly released 180-W device, which is emerging as a more powerful and faster treatment compared with the 80- and 120-W counterparts, representing the future of KTP laser vaporization. A few more data need additional investigation and could be the subject of future studies. First, the method used by the authors does not detect CO, which, in previous studies of the chemical composition of gases produced during transurethral resection and transurethral vaporization of the prostate has been shown to be produced in significantly greater levels than the other compounds detected. 4,5 In the report by Weston et al,4 the mean CO level recorded throughout the duration of the procedures was 7 parts per million (ppm), and in 4 of 12 procedures, the peak CO level reached the maximal detectable level by the apparatus at 490 ppm, suggesting that levels greater than those occurred.4 According to the Occupational Safety and Health Administration, the maximak exposure to CO should be _35 ppm for no longer than 8 hours and the limit for short-term exposure (15-minutes reference period) is 200 ppm.6 Second, it has been shown that lasers and ultrasonic devices produce a plume, which contains larger particulate matter than smoke, _0.3 _m and _0.35-6.5 _m, respectively, and larger particles have greater biologic hazards than small particles.5 Awareness of the health risk/infectious potential of laser-generated viable particles has been increasing.5 Numerous studies have been conducted to examine the virus viability of laser smoke and showed viable and, therefore, potentially contagious viral DNA in the laser aerosol.5 Additional studies are needed to evaluate the gases produced, including CO and viable viral DNA particles, with 120-W laser prostatectomy and the newly released 180-W system The authors present a comparison of harmful gases produced during GreenLight HPS laser prostatectomy operating at 120W and TURVP. Overall, their report is well written, and the method used is correct; however, one might criticize their study, because they chose to perform the 2 procedures (TURVP followed by HPS laser prostatectomy) in the same patient. Others would have chosen to create 2 distinct groups, 1 for TURVP and 1 for HPS laser prostatectomy. In the present study, precise endpoints were adopted, and the results are interesting from a scientific viewpoint and quite promising for HPS laser prostatectomy. The authors conclude that the surgical smoke produced from TURVP and HPS laser prostatectomy contains potentially harmful chemical compounds, but HPS laser prostatectomy produced significantly less chemical components than TURVP. However, harmful chemical components, including 1,3-butadiene, a human carcinogen, were still released during HPS laser prostatectomy. The authors also compared the gases generated from HPS laser prostatectomy using Urosol, an irrigation solution comprising 2.7% sorbitol and 0.54% mannitol, with the gas production using normal saline solution and concluded that Urosol produced fewer types and a smaller amount of gases than normal saline. Photoselective vaporization of the prostate involving the GreenLight KTP laser was first introduced in 1998 by Malek et al.1 Since 1998, it has evolved from the GreenLight 80-W KTP powered laser through to the latest 180-W XPS laser involving a MoXy fiber.2 The key features of the new 180-W XPS laser are faster lasing speed and higher energy application. Bachmann et al,3 from the International GreenLight Users group, recently reported a comparative analysis of the energy use and lasing times found with the 3 systems. On average, with the 80-W system, a prostate of 55 cm3 was treated with 154 kJ, with the 120-W HPS laser, a prostate size of 61 cm3 was vaporized with 251 kJ (_60%), and with the 180-W XPS laser, a 67-cm3 prostate was treated with 324 kJ.3 Therefore, the results regarding gas production are expected to change with the newly released 180-W device, which is emerging as a more powerful and faster treatment compared with the 80- and 120-W counterparts, representing the future of KTP laser vaporization. A few more data need additional investigation and could be the subject of future studies. First, the method used by the authors does not detect CO, which, in previous studies of the chemical composition of gases produced during transurethral resection and transurethral vaporization of the prostate has been shown to be produced in significantly greater levels than the other compounds detected. 4,5 In the report by Weston et al,4 the mean CO level recorded throughout the duration of the procedures was 7 parts per million (ppm), and in 4 of 12 procedures, the peak CO level reached the maximal detectable level by the apparatus at 490 ppm, suggesting that levels greater than those occurred.4 According to the Occupational Safety and Health Administration, the maximak exposure to CO should be _35 ppm for no longer than 8 hours and the limit for short-term exposure (15-minutes reference period) is 200 ppm.6 Second, it has been shown that lasers and ultrasonic devices produce a plume, which contains larger particulate matter than smoke, _0.3 _m and _0.35-6.5 _m, respectively, and larger particles have greater biologic hazards than small particles.5 Awareness of the health risk/infectious potential of laser-generated viable particles has been increasing.5 Numerous studies have been conducted to examine the virus viability of laser smoke and showed viable and, therefore, potentially contagious viral DNA in the laser aerosol.5 Additional studies are needed to evaluate the gases produced, including CO and viable viral DNA particles, with 120-W laser prostatectomy and the newly released 180-W system The authors present a comparison of harmful gases produced during GreenLight HPS laser prostatectomy operating at 120W and TURVP. Overall, their report is well written, and the method used is correct; however, one might criticize their study, because they chose to perform the 2 procedures (TURVP followed by HPS laser prostatectomy) in the same patient. Others would have chosen to create 2 distinct groups, 1 for TURVP and 1 for HPS laser prostatectomy. In the present study, precise endpoints were adopted, and the results are interesting from a scientific viewpoint and quite promising for HPS laser prostatectomy. The authors conclude that the surgical smoke produced from TURVP and HPS laser prostatectomy contains potentially harmful chemical compounds, but HPS laser prostatectomy produced significantly less chemical components than TURVP. However, harmful chemical components, including 1,3-butadiene, a human carcinogen, were still released during HPS laser prostatectomy. The authors also compared the gases generated from HPS laser prostatectomy using Urosol, an irrigation solution comprising 2.7% sorbitol and 0.54% mannitol, with the gas production using normal saline solution and concluded that Urosol produced fewer types and a smaller amount of gases than normal saline. Photoselective vaporization of the prostate involving the GreenLight KTP laser was first introduced in 1998 by Malek et al.1 Since 1998, it has evolved from the GreenLight 80-W KTP powered laser through to the latest 180-W XPS laser involving a MoXy fiber.2 The key features of the new 180-W XPS laser are faster lasing speed and higher energy application. Bachmann et al,3 from the International GreenLight Users group, recently reported a comparative analysis of the energy use and lasing times found with the 3 systems. On average, with the 80-W system, a prostate of 55 cm3 was treated with 154 kJ, with the 120-W HPS laser, a prostate size of 61 cm3 was vaporized with 251 kJ (_60%), and with the 180-W XPS laser, a 67-cm3 prostate was treated with 324 kJ.3 Therefore, the results regarding gas production are expected to change with the newly released 180-W device, which is emerging as a more powerful and faster treatment compared with the 80- and 120-W counterparts, representing the future of KTP laser vaporization. A few more data need additional investigation and could be the subject of future studies. First, the method used by the authors does not detect CO, which, in previous studies of the chemical composition of gases produced during transurethral resection and transurethral vaporization of the prostate has been shown to be produced in significantly greater levels than the other compounds detected. 4,5 In the report by Weston et al,4 the mean CO level recorded throughout the duration of the procedures was 7 parts per million (ppm), and in 4 of 12 procedures, the peak CO level reached the maximal detectable level by the apparatus at 490 ppm, suggesting that levels greater than those occurred.4 According to the Occupational Safety and Health Administration, the maximak exposure to CO should be _35 ppm for no longer than 8 hours and the limit for short-term exposure (15-minutes reference period) is 200 ppm.6 Second, it has been shown that lasers and ultrasonic devices produce a plume, which contains larger particulate matter than smoke, _0.3 _m and _0.35-6.5 _m, respectively, and larger particles have greater biologic hazards than small particles.5 Awareness of the health risk/infectious potential of laser-generated viable particles has been increasing.5 Numerous studies have been conducted to examine the virus viability of laser smoke and showed viable and, therefore, potentially contagious viral DNA in the laser aerosol.5 Additional studies are needed to evaluate the gases produced, including CO and viable viral DNA particles, with 120-W laser prostatectomy and the newly released 180-W system