title: The optimization of laser prostatectomy. Part I: Free beam side fire coagulation.
abstract: OBJECTIVE
  To study laser-tissue interaction and develop unifying principles for the optimization of free beam side fire neodymium:yttrium-aluminum-garnet (Nd:YAG) laser coagulation prostatectomy.
  
  
  METHODS
  The heating patterns and coagulation volumes created by different right angle deflecting fibers were studied at different wattages and times in potato and canine models.
  
  
  RESULTS
  In the potato, higher wattage resulted in deeper and more rapid heating. The high power density fibers created lesions of smaller volume which increased less with rising wattage than those fibers of lower power density. In the canine model, carbonization decreased heat penetration, and "popcorn" decreased superficial temperature without altering lesion size as long as it occurred without carbonization. As lasing progressed, smaller incremental increases in coagulation depth were achieved.
  
  
  CONCLUSIONS
  To optimize coagulation laser prostatectomy, the surgeon should operate at the highest wattage which does not cause carbonization. The visualized intraoperative laser-tissue interaction allows the adjustment of laser power during the case as needed.
authors.affiliation: Department of Urology, James Buchanan Brady Foundation, New York Hospital-Cornell Medical Center, New York, New York.
authors.forename: A P
authors.initials: AP
authors.lastname: Perlmutter
authors.forename: R
authors.initials: R
authors.lastname: Muschter
mesh_terms: D000818:Animals; D004285:Dogs; D004560:Electricity; D017075:Laser Coagulation / Q000379:methods*; D008297:Male; D011467:Prostate / Q000473:pathology / Q000528:radiation effects; D011468:Prostatectomy / Q000379:methods*; D013696:Temperature; D013997:Time Factors