title: Application of botulinum toxin type A in myocutaneous flap expansion.
abstract: BACKGROUND
  Although the use of the expanded myocutaneous flap has many advantages, the time course is prolonged. The net gain in surface area during acute expansion is insufficient. In this study, botulinum toxin type A was applied to shorten the flap expansion period while obtaining an adequate surface area that would meet surgical requirements.
  
  
  METHODS
  Seven minipigs were used for the authors' experiments. Two sides of the dorsolumbar section in each pig were divided randomly into the botulinum toxin type A-treated and the saline-treated groups. Two 200-ml expanders were implanted in the submuscular pocket. Inflation began 2 weeks later, and the period of expansion was observed in a double-blind manner. Two weeks after the final inflation, the expansion area was measured, and a 10 x 6-cm myocutaneous flap was elevated and sutured in situ, and the contraction of the myocutaneous flap was observed.
  
  
  RESULTS
  Botulinum toxin type A shortened the expansion time by 17 days (p < 0.001). The average increment of effective expansion area (p = 0.009) and the average recruitment area (p = 0.001) in the botulinum toxin type A-treated group were significantly higher than in the saline-treated group. Moreover, contraction in axial length and width of the botulinum toxin type A-treated group was lower than that of the saline-treated group at each time point following transposition (p < 0.001).
  
  
  CONCLUSIONS
  Botulinum toxin type A could decrease the resistance to myocutaneous flap expansion, speed up the inflation, increase the expansion area, and reduce the contraction of the myocutaneous flap. It is a safe and convenient method with which to assist myocutaneous flap expansion.
authors.affiliation: Tangshan and Beijing, People's Republic of China From the Tangshan Worker's Hospital, Hebei Medical University; Beijing Hospital, Chinese Ministry of Health; Plastic Surgery Hospital, Peking Union Medical College, Chinese Academy of Medical Science; and No. 2 Hospital affiliated to General Hospital of the Chinese People's Liberation Army.
authors.forename: Duan
authors.initials: D
authors.lastname: Chenwang
authors.forename: Bao
authors.initials: B
authors.lastname: Shiwei
authors.forename: Yu
authors.initials: Y
authors.lastname: Dashan
authors.forename: Li
authors.initials: L
authors.lastname: Qiang
authors.forename: Chen
authors.initials: C
authors.lastname: Bin
authors.forename: Zhao
authors.initials: Z
authors.lastname: Muxin
authors.forename: Li
authors.initials: L
authors.lastname: Pengcheng
authors.forename: Li
authors.initials: L
authors.lastname: Senkai
mesh_terms: D000818:Animals; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000627:therapeutic use*; D006085:Graft Survival; D007267:Injections; D023421:Models, Animal; D009465:Neuromuscular Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D013524:Surgical Flaps; D013552:Swine; D013556:Swine, Miniature; D013997:Time Factors; D015626:Tissue Expansion / Q000379:methods*; D015625:Tissue Expansion Devices
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A