title: Optimizing fluence and debridement effects on cutaneous resurfacing carbon dioxide laser surgery.
abstract: OBJECTIVE
  To develop methods to compare carbon dioxide (CO2) resurfacing lasers, fluence, and debridement effects on tissue shrinkage and histological thermal denaturation.
  
  
  METHODS
  In vitro human or in vivo porcine skin samples received up to 5 passes with scanner or short-pulsed CO2 resurfacing lasers. Fluences ranging from 2.19 to 17.58 J/cm2 (scanner) and 1.11 to 5.56 J/cm2 (short pulsed) were used to determine each laser's threshold energy for clinical effect. Variable amounts of debridement were also studied.
  
  
  METHODS
  Tissue shrinkage was evaluated by using digital photography to measure linear distance change of the treated tissue. Tissue histological studies were evaluated using quantitative computer image analysis.
  
  
  RESULTS
  Fluence-independent in vitro tissue shrinkage was seen with the scanned and short-pulsed lasers above threshold fluence levels of 5.9 and 2.5 J/cm2, respectively. Histologically, fluence-independent thermal depths of damage of 77 microns (scanner) and 25 microns (pulsed) were observed. Aggressive debridement of the tissue increased the shrinkage per pass of the laser, and decreased the fluence required for the threshold effect. In vivo experiments confirmed the in vitro results, although the in vivo threshold fluence level was slightly higher and the shrinkage obtained was slightly lower per pass.
  
  
  CONCLUSIONS
  Our methods allow comparison of different resurfacing lasers' acute effects. We found equivalent laser tissue effects using lower fluences than those currently accepted clinically. This suggests that the morbidity associated with CO2 laser resurfacing may be minimized by lowering levels of tissue input energy and controlling for tissue debridement.
authors.affiliation: Department of Otolaryngology, Vanderbilt University Medical Center, Nashville, Tenn., USA.
authors.forename: N K
authors.initials: NK
authors.lastname: Weisberg
authors.forename: T
authors.initials: T
authors.lastname: Kuo
authors.forename: B
authors.initials: B
authors.lastname: Torkian
authors.forename: L
authors.initials: L
authors.lastname: Reinisch
authors.forename: D L
authors.initials: DL
authors.lastname: Ellis
mesh_terms: D000818:Animals; D002245:Carbon Dioxide; D003646:Debridement; D062109:Dermatologic Surgical Procedures; D006801:Humans; D066298:In Vitro Techniques; D053685:Laser Therapy; D012867:Skin / Q000473:pathology*; D013552:Swine
chemical_list: D002245:Carbon Dioxide