title: Evaluation of the effect of fractional CO2 laser on histopathological picture and TGF-β1 expression in hypertrophic scar.
abstract: OBJECTIVE
  Hypertrophic scar is a form of abnormal wound healing process in which tissue repair regulating mechanism is disrupted. Transforming growth factor β1 has a particular importance in the fibrotic scarring response. Treatment of hypertrophic scar included many chemical, physical, and surgical options. Fractional CO2 laser devices have gained acceptance as a way for managing hypertrophic scar. Aims of this study are: (a) to determine the clinical and histopathological effects of fractional CO2 laser on hypertrophic scar, (b) to evaluate the expression pattern of transforming growth factor-β1 (TGF-β1) as an important fibrogenic factor before and 6 months after fractional CO2 laser treatment.
  
  
  METHODS
  Forty patients of hypertrophic scar were selected, each patient was treated by four sessions with 1 month apart with fractional CO2 laser. Vancouver Scar Scale (VSS) was used to assess the patients before and after laser treatment. Skin biopsy was taken from eight cases before and 3 months after four fractional CO2 laser sessions and four normal skin control biopsies. All were assessed by hematoxylin-eosin (H&E), Masson's trichrome, Van Gieson and immunohistochemical (IHC) staining with TGF-β1. The epidermal thickness was assessed before and after treatment by image analyzing system software.
  
  
  RESULTS
  There was statistically significant difference in VSS before and after fractional CO2 laser (P > 0.001). The epidermal thickness showed significant increase after laser treatment (P > 0.001), and there was also thinning in stratum corneum and replacement of the irregular collagen bands with organized new collagen fibrils as demonstrated by H&E and the other special stains. The study also showed significant decrease in TGF-β1 expression after laser therapy (P = 0.008).
  
  
  CONCLUSIONS
  Fractional CO2 laser could be considered as a good way for hypertrophic scar management. It normalizes dermal collagen as imaged by histopathological picture and the change in TGF-β1 expression.
authors.affiliation: Faculty of Medicine, Plastic Surgery Department, Assiut University, Assiut, Egypt.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Makboul
authors.forename: Rania
authors.initials: R
authors.lastname: Makboul
authors.forename: Assem Hk
authors.initials: AH
authors.lastname: Abdelhafez
authors.forename: Safaa Said
authors.initials: SS
authors.lastname: Hassan
authors.forename: Sherif M
authors.initials: SM
authors.lastname: Youssif
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D017439:Cicatrix, Hypertrophic / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy*; D003094:Collagen / Q000378:metabolism; D004890:Erythema / Q000473:pathology; D005260:Female; D006801:Humans; D054020:Lasers, Gas / Q000627:therapeutic use*; D028022:Low-Level Light Therapy; D008297:Male; D012867:Skin / Q000378:metabolism / Q000473:pathology; D012880:Skin Pigmentation; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D055815:Young Adult
chemical_list: D053773:Transforming Growth Factor beta1; D003094:Collagen
keywords: TGF-β1; fractional CO2 laser; histopathological picture; hypertrophic scar