title: Ex vivo efficacy evaluation of laser vaporization for treatment of benign prostatic hyperplasia using a 300-W high-power laser diode with a wavelength of 980 nm.
abstract: OBJECTIVE
  Laser vaporization of the prostate is considered to be a promising treatment for benign prostatic hyperplasia (BPH), and efficiency of vaporization and hemostasis are both important parameters for such treatment. In this study, we used a high-power laser diode with a wavelength of 980 nm to obtain high vaporization efficiency with good hemostasis. The objective of this study is to evaluate the efficacy of laser vaporization for treatment of BPH in ex vivo experiments using a 300-W high-power laser diode with a wavelength of 980 nm quantitatively.
  
  
  METHODS
  An ex vivo experimental setup simulating clinical treatment situation was constructed. Bovine prostate tissue was used as a sample. The power setting was 100, 150, 200, 250, or 300 W, and the irradiation time was 0.5, 1, or 2 s. After laser irradiation, vaporized and coagulated depths were measured.
  
  
  RESULTS
  The vaporized depth increased with the laser power and irradiation time, and the results confirmed that the high-power laser diode could efficiently vaporize the prostate tissue. Coagulated depth increased as the laser power became higher.
  
  
  CONCLUSIONS
  Laser vaporization of prostate tissue using a high-power laser diode with a wavelength of 980 nm represents a promising treatment for BPH; this method exhibits high vaporization efficiency and good hemostasis. However, operators must be aware of the risk of postoperative perforation of the prostatic capsule caused by coagulation of deep regions that cannot be visualized by endoscopic observation.
authors.affiliation: Graduate School of Engineering, Osaka University.
authors.forename: Junya
authors.initials: J
authors.lastname: Takada
authors.affiliation: Institute for Academic Initiatives, Osaka University.
authors.forename: Norihiro
authors.initials: N
authors.lastname: Honda
authors.affiliation: Graduate School of Engineering, Osaka University.
authors.forename: Hisanao
authors.initials: H
authors.lastname: Hazama
authors.affiliation: Graduate School of Engineering, Osaka University ; Graduate School of Frontier Biosciences, Osaka University ; The Center for Advanced Medical Engineering and Informatics, Osaka University.
authors.forename: Kunio
authors.initials: K
authors.lastname: Awazu
keywords: absorption coefficient; laser surgery; scattering coefficient; transurethral vaporization of the prostate