title: Treatment of resistant port-wine stains with a pulsed dual wavelength 595 and 1064 nm laser: a histochemical evaluation of the vessel wall destruction and selectivity.
abstract: OBJECTIVE
  Pulsed dye laser (PDL) is the current treatment of choice for port-wine stains (PWS), but 25-50% of treated lesions do not demonstrate a significant improvement. Hybrid lasers may improve treatment efficacy, especially those using the synergies between PDL and Nd:YAG 1064 nm laser. The objectives of this study were to assess vessel wall damage and epidermal sparing after a dual wavelength treatment with the two lasers, using different laser parameters.
  
  
  METHODS
  Post-treatment biopsies, after using a laser platform that allows sequential pulses of PDL and Nd:YAG 1064 nm lasers, were performed in five patients with PWS resistant to PDL. The biopsies were stained with nitroblue-tetrazolium chloride (NBTC), using enzymatic activity that stops immediately after cell death and allows a better identification of viable cells.
  
  
  RESULTS
  Five patients with PWS and a median age of 33 years were enrolled in this study. Selectivity and efficacy was observed with this dual wavelength approach, with the best results observed with PDL pulses shorter than 10 ms, use of the 10 mm spot, and a second pass with PDL only.
  
  
  CONCLUSIONS
  Histochemical studies with NBTC stain can help the laser surgeon establish the best treatment parameters and understand some of the unwanted side effects. The dual wavelength used in this study showed efficacy, but better assessment of treatment parameters, such as the delay between the two lasers, is needed to avoid side effects.
authors: Department of Dermatology, Hospital de Santa Maria, Lisboa, Portugal. joaobc77@hotmail.com
authors: João
authors: J
authors: Borges da Costa
authors: Pablo
authors: P
authors: Boixeda
authors: Carmen
authors: C
authors: Moreno
authors: Juan
authors: J
authors: Santiago
mesh_terms: D000293:Adolescent; D000328:Adult; D001808:Blood Vessels / Q000473:pathology / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004817:Epidermis / Q000473:pathology / Q000528:radiation effects*; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D007202:Indicators and Reagents; D054025:Lasers, Dye; D053844:Lasers, Solid-State; D028022:Low-Level Light Therapy; D008297:Male; D008875:Middle Aged; D009580:Nitroblue Tetrazolium; D019339:Port-Wine Stain / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*
chemical_list: D007202:Indicators and Reagents; D009580:Nitroblue Tetrazolium