title: The biological effects of quadripolar radiofrequency sequential application: a human experimental study.
abstract: OBJECTIVE
  An experimental study was conducted to assess the effectiveness and safety of an innovative quadripolar variable electrode configuration radiofrequency device with objective measurements in an ex vivo and in vivo human experimental model.
  
  
  BACKGROUND
  Nonablative radiofrequency applications are well-established anti-ageing procedures for cosmetic skin tightening.
  
  
  METHODS
  The study was performed in two steps: ex vivo and in vivo assessments. In the ex vivo assessments the radiofrequency applications were performed on human full-thickness skin and subcutaneous tissue specimens harvested during surgery for body contouring. In the in vivo assessments the applications were performed on two volunteer patients scheduled for body contouring surgery at the end of the study. The assessment methods were: clinical examination and medical photography, temperature measurement with thermal imaging scan, and light microscopy histological examination.
  
  
  RESULTS
  The ex vivo assessments allowed for identification of the effective safety range for human application. The in vivo assessments allowed for demonstration of the biological effects of sequential radiofrequency applications. After a course of radiofrequency applications, the collagen fibers underwent an immediate heat-induced rearrangement and were partially denaturated and progressively metabolized by the macrophages. An overall thickening and spatial rearrangement was appreciated both in the collagen and elastic fibers, the latter displaying a juvenile reticular pattern. A late onset in the macrophage activation after sequential radiofrequency applications was appreciated.
  
  
  CONCLUSIONS
  Our data confirm the effectiveness of sequential radiofrequency applications in obtaining attenuation of the skin wrinkles by an overall skin tightening.
authors.affiliation: 1 Plastic and Reconstructive Surgery, Department of Clinical Surgical Diagnostic and Pediatric Sciences, University of Pavia , Pavia, Italy .
authors.forename: Giovanni
authors.initials: G
authors.lastname: Nicoletti
authors.forename: Antonia Icaro
authors.initials: AI
authors.lastname: Cornaglia
authors.forename: Angela
authors.initials: A
authors.lastname: Faga
authors.forename: Silvia
authors.initials: S
authors.lastname: Scevola
mesh_terms: D061645:Abdominoplasty / Q000295:instrumentation / Q000379:methods*; D000273:Adipose Tissue / Q000528:radiation effects*; D003357:Cosmetic Techniques / Q000295:instrumentation*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D061214:Patient Safety; D000078702:Radiofrequency Therapy; D012060:Rejuvenation; D015595:Skin Aging / Q000528:radiation effects*; D013696:Temperature