title: Angiogenic effects of cryosurgery with liquid nitrogen on the normal skin of rats, through morphometric study.
abstract: BACKGROUND
  Cryosurgery is an efficient therapeutic technique used to treat benign and malignant cutaneous diseases. The primary active mechanism of cryosurgery is related to vascular effects on treated tissue. After a cryosurgical procedure, exuberant granulation tissue is formed at the injection site, probably as a result of angiogenic stimulation of the cryogen and inflammatory response, particularly in endothelial cells.
  
  
  OBJECTIVE
  To evaluate the angiogenic effects of freezing, as part of the phenomenon of healing rat skin subjected to previous injury.
  
  
  METHODS
  Two incisions were made in each of the twenty rats, which were divided randomly into two groups of ten. After 3 days, cryosurgery with liquid nitrogen was performed in one of incisions. The rats' samples were then collected, cut and stained to conduct histopathological examination, to assess the local angiogenesis in differing moments and situations.
  
  
  RESULTS
  It was possible to demonstrate that cryosurgery, in spite of promoting cell death and accentuated local inflammation soon after its application, induces quicker cell proliferation in the affected tissue and maintenance of this rate in a second phase, than in tissue healing without this procedure.
  
  
  CONCLUSIONS
  These findings, together with the knowledge that there is a direct relationship between mononuclear cells and neovascularization (the development of a rich system of new vessels in injury caused by cold), suggest that cryosurgery possesses angiogenic stimulus, even though complete healing takes longer to occur. The significance level for statistical tests was 5% (p<0,05).
authors.affiliation: aff01.
authors.forename: Camila Bianco
authors.initials: CB
authors.lastname: Pimentel
authors.affiliation: Universidade Estadual de Campinas, Campinas, SP, Brazil.
authors.forename: Aparecida Machado de
authors.initials: AM
authors.lastname: Moraes
authors.affiliation: Universidade Estadual de Campinas, Campinas, SP, Brazil.
authors.forename: Maria Letícia
authors.initials: ML
authors.lastname: Cintra
mesh_terms: D000818:Animals; D002452:Cell Count; D003452:Cryosurgery / Q000379:methods*; D062109:Dermatologic Surgical Procedures / Q000379:methods*; D008297:Male; D018919:Neovascularization, Physiologic / Q000502:physiology*; D009584:Nitrogen / Q000627:therapeutic use*; D011897:Random Allocation; D051381:Rats; D011917:Rats, Inbred Lew; D015203:Reproducibility of Results; D013997:Time Factors; D014945:Wound Healing / Q000502:physiology
chemical_list: D009584:Nitrogen