title: Effect of topically applied minoxidil on the survival of rat dorsal skin flap.
abstract: BACKGROUND
  Flap necrosis still is a challenging problem in reconstructive surgery that results in irreversible tissue loss. This study evaluated the effect of topically applied minoxidil on angiogenesis and survival of a caudally based dorsal rat skin flap.
  
  
  METHODS
  For this study, 24 male Wistar rats were randomly divided into three groups of eight each. A caudally based dorsal skin flap with the dimensions of 9 × 3 cm was raised. After elevation of the flaps, they were sutured back into their initial positions. In group 1 (control group), 1 ml of isotonic saline was applied topically to the flaps of all the animals for 14 days. In group 2, minoxidil solution was spread uniformly over the flap surface for 7 days after the flap elevation. In group 3, minoxidil solution was applied topically to the flap surface during a 14-day period. On day 7 after the flap elevation, the rats were killed. The average area of flap survival was determined for each rat. Subdermal vascular architecture and angiogenesis were evaluated under a light microscope after two full-thickness skin biopsy specimens had been obtained from the midline of the flaps.
  
  
  RESULTS
  The lowest flap survival rate was observed in group 1, and no difference was observed between groups 1 and 2. Compared with groups 1 and 2, group 3 had a significantly increased percentage of flap survival (P < 0.05). Intense and moderate angiogenesis also was observed respectively at the proximal and distal areas of the flaps in group 3.
  
  
  CONCLUSIONS
  The results of this experiment seem to show that the early effect of minoxidil is vasodilation and that prolonged use before flap elevation leads to angiogenesis, increasing flap viability.
  
  
  METHODS
  This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors                      www.springer.com/00266                                        .
authors.affiliation: Department of Plastic, Reconstructive, and Aesthetic Surgery, Cumhuriyet University Medical Faculty, Sivas, Turkey. gumus1970@hotmail.com
authors.forename: Nazım
authors.initials: N
authors.lastname: Gümüş
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Odemiş
authors.forename: Sarper
authors.initials: S
authors.lastname: Yılmaz
authors.forename: Ersin
authors.initials: E
authors.lastname: Tuncer
mesh_terms: D000287:Administration, Topical; D000818:Animals; D006085:Graft Survival / Q000187:drug effects*; D008297:Male; D008914:Minoxidil / Q000008:administration & dosage* / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013524:Surgical Flaps; D014665:Vasodilator Agents / Q000008:administration & dosage* / Q000494:pharmacology
chemical_list: D014665:Vasodilator Agents; D008914:Minoxidil