title: Cryogen spray cooling in conjunction with pulse dye laser treatment of port wine stains of the head and neck.
abstract: BACKGROUND
  When a cryogen spurt is applied to the skin surface for an appropriately short period of time, the spatial distribution of cooling remains localized in the normal overlying epidermis, while leaving the temperature of deeper port wine stain (PWS) blood vessels unchanged. Furthermore, cooling continues after pulsed laser exposure as cryogen remaining on the surface evaporates and removes heat deposited by light absorption in epidermal melanin. The objective of this study was to evaluate the efficacy and advantages of cryogen spray cooling plus flashlamp-pumping in conjunction with dye laser treatment (CSC-LT) of PWS.
  
  
  METHODS
  From 1996 to 2000, a retrospective study was conducted on 63 patients, consisting of 43 women and 20 men, between the ages of 8 and 62 years treated with pulsed dye laser (lambda = 585 nm, tau p = 450 microseconds) over a 4-year period. The duration of cryogen spurts and the delay period between cryogen delivery and laser illumination were controlled. An infrared focal plane array thermodetector measured changes of lesion surface temperature which were recorded. The subject was asked to score discomfort during treatment using a pain scale. The primary efficacy measure was the quantitative assessment of a blanching response score.
  
  
  RESULTS
  The ambient skin surface temperature of PWS was 33.31 +/- 1.55 degrees C. The mean pain score for uncooled sites was 39.85 +/- 0.23 compared to 20.18 +/- 0.15 for cooled sites. There was a statistically significant difference in pain elimination between cooled and uncooled sites (p = 0.001). The mean blanching response score of CSC-LT was 3.70. A significant blanching response of PWS when receiving CSC-LT was noted.
  
  
  CONCLUSIONS
  Our clinical studies demonstrate the feasibility of selective epidermal cooling while achieving photothermolysis of blood vessels during pulsed dye laser treatment of PWS.
authors.affiliation: Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, Taipei, Chang Gung University, Taoyuan, Taiwan, R.O.C.
authors.forename: P S
authors.initials: PS
authors.lastname: Huang
authors.forename: C J
authors.initials: CJ
authors.lastname: Chang
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003080:Cold Temperature; D005260:Female; D006257:Head; D006801:Humans; D053685:Laser Therapy; D008297:Male; D008875:Middle Aged; D009333:Neck; D019339:Port-Wine Stain / Q000628:therapy*; D012189:Retrospective Studies; D012881:Skin Temperature