title: A histopathological comparison of "char-free" carbon dioxide lasers.
abstract: BACKGROUND
  New "char-free" carbon dioxide lasers are capable of precise tissue vaporization with minimal residual thermal damage. These lasers operate either by producing high energy, rapid pulses or by scanning a highly focused continuous mode beam.
  
  
  OBJECTIVE
  To determine the depth of ablation and the depth of residual thermal injury produced with one to three passes of the pulsed and scanned systems.
  
  
  METHODS
  The distal ends of preauricular donor skin from 12 patients requiring full-thickness skin grafts following Mohs micrographic surgery were treated with zero to three passes of each of the lasers, and fixed for histopathological analysis.
  
  
  RESULTS
  The three lasers tested produced vaporization of thin (20-50 microns) layers of tissue and narrow (20-150 microns) zones of thermal injury following one, two, or three passes on intact skin.
  
  
  CONCLUSIONS
  The pulsed and scanned technologies are capable of producing "char-free" tissue ablation with minimal residual thermal damage.
authors.affiliation: Laser and Skin Surgery Center of New York, New York, USA.
authors.forename: A N
authors.initials: AN
authors.lastname: Kauvar
authors.forename: H A
authors.initials: HA
authors.lastname: Waldorf
authors.forename: R G
authors.initials: RG
authors.lastname: Geronemus
mesh_terms: D002056:Burns / Q000209:etiology / Q000517:prevention & control; D002245:Carbon Dioxide; D062109:Dermatologic Surgical Procedures; D006801:Humans; D053685:Laser Therapy / Q000009:adverse effects / Q000379:methods*; D015580:Mohs Surgery / Q000379:methods; D012867:Skin / Q000473:pathology; D016038:Skin Transplantation
chemical_list: D002245:Carbon Dioxide