title: High-powered holmium-laser ablation: comparison of setting effectiveness using tissue-surrogate model.
abstract: OBJECTIVE
  The 100-W holmium laser, in conjunction with a sidefiring 550-microm fiber, can ablate prostate glands as large as 40 g to relieve lower urinary-tract symptoms. We evaluated the effect of various setting combinations on ablation efficiency using beef kidney as a tissue-surrogate model.
  
  
  METHODS
  Beef kidney specimens (mean weight 44.8 +/- 3.1 g) were secured in a cylinder, which was submerged in a water-filled tank through which a 27F resectoscope and 550-microm sidefiring fiber were positioned. Four energy/frequency combinations were tested, with each used to treat 10 kidney specimens. The difference between the mean pretreatment and post-treatment weights of each treatment group were compared statistically with Student's t-test.
  
  
  RESULTS
  The largest mean weight difference after treatment (8.94 +/- 2.38 g) was achieved using 3.2 J and 25 Hz. This mass reduction was significantly greater than that of all other combinations except 2.5 J and 40 Hz.
  
  
  CONCLUSIONS
  Use of the 3.2 J and 25 Hz setting combination resulted in the greatest amount of ablation in this tissue-surrogate model, suggesting that maximal energy settings may provide an advantage in tissue vaporization using the 100-W holmium laser. Clinical assessment must be performed to substantiate these findings.
authors.affiliation: Department of Urology, Thomas Jefferson University, Jefferson Medical College, Philadelphia, Pennsylvania 19107, USA. ramsay.kuo@jefferson.edu
authors.forename: Ramsay L
authors.initials: RL
authors.lastname: Kuo
authors.forename: Ryan F
authors.initials: RF
authors.lastname: Paterson
authors.forename: Tibério M
authors.initials: TM
authors.lastname: Siqueira
authors.forename: Samuel C
authors.initials: SC
authors.lastname: Kim
authors.forename: James E
authors.initials: JE
authors.lastname: Lingeman
mesh_terms: D000818:Animals; D002417:Cattle; D006695:Holmium; D007668:Kidney / Q000033:anatomy & histology* / Q000601:surgery*; D053685:Laser Therapy / Q000379:methods*; D023421:Models, Animal; D009929:Organ Size
chemical_list: D006695:Holmium