title: New alternatives for laser vaporization of the prostate: experimental evaluation of a 980-, 1,318- and 1,470-nm diode laser device.
abstract: OBJECTIVE
  Several diode laser systems were introduced in recent years for the minimal-invasive surgical therapy of benign prostate enlargement. We investigated the ablation capacities, hemostatic properties and extend of tissue necrosis of different diode lasers at wavelengths of 980, 1,318 and 1,470 nm and compared the results to the 120 W GreenLight HPS laser.
  
  
  METHODS
  The laser devices were evaluated in an ex vivo model using isolated porcine kidneys. The weight difference of the porcine kidneys after 10 min of laser vaporization defined the amount of ablated tissue. Blood loss was measured in blood-perfused kidneys following laser vaporization. Histological examination was performed to assess the tissue effects.
  
  
  RESULTS
  The side-firing 980 and 1,470 nm diode lasers displayed similar ablative capacities compared to the GreenLight HPS laser (n.s.). The 1,318-nm laser, equipped with a bare-ended fiber, reached a higher ablation rate compared to the other laser devices (each P < 0.05). A calculated 'output power efficiency per watt' revealed that the 1,318-nm laser with a bare-ended fiber reached the highest rate compared to the side-firing devices (each P < 0.0001). All three diode lasers showed superior hemostatic properties compared to the GreenLight HPS laser (each P < 0.01). The extend of morphological tissue necrosis was 4.62 mm (1,318 nm), 1.30 mm (1,470 nm), 4.18 mm (980 nm) and 0.84 mm (GreenLight HPS laser), respectively.
  
  
  CONCLUSIONS
  The diode lasers offered similar ablative capacities and improved hemostatic properties compared to the 120 W GreenLight HPS laser in this experimental ex vivo setting. The higher tissue penetration of the diode lasers compared to the GreenLight HPS laser may explain improved hemostasis.
authors.affiliation: Department of Urology, Mannheim Medical Center, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany. felix.wezel@medma.uni-heidelberg.de
authors.forename: Felix
authors.initials: F
authors.lastname: Wezel
authors.forename: Gunnar
authors.initials: G
authors.lastname: Wendt-Nordahl
authors.forename: Nina
authors.initials: N
authors.lastname: Huck
authors.forename: Thorsten
authors.initials: T
authors.lastname: Bach
authors.forename: Christel
authors.initials: C
authors.lastname: Weiss
authors.forename: Maurice Stephan
authors.initials: MS
authors.lastname: Michel
authors.forename: Axel
authors.initials: A
authors.lastname: Häcker
mesh_terms: D000818:Animals; D016063:Blood Loss, Surgical / Q000517:prevention & control; D006487:Hemostasis; D053685:Laser Therapy / Q000295:instrumentation* / Q000379:methods; D054023:Lasers, Semiconductor; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation* / Q000379:methods; D009336:Necrosis; D011183:Postoperative Complications / Q000473:pathology / Q000517:prevention & control; D011467:Prostate / Q000473:pathology / Q000601:surgery*; D011470:Prostatic Hyperplasia / Q000601:surgery; D013552:Swine; D020728:Transurethral Resection of Prostate / Q000295:instrumentation* / Q000379:methods