title: Blood Congestion Can Be Rescued by Hemodilution in a Random-Pattern Skin Flap.
abstract: BACKGROUND
  There is no standard method to ensure survival of random-pattern skin flaps. The authors developed a rat anemia model to observe survival of random-pattern skin flaps after blood transfusion and hemodilution.
  
  
  METHODS
  Anemia was induced by withdrawal of 35 percent blood volume followed by compensation with the same amount of blood (blood transfusion model) or plasma equivalent (normovolemic hemodilution). Control rats were subjected to a sham procedure. Subsequently, a random-pattern skin flap (1.5 × 6 cm) was elevated on the back of each rat. Physiologic assessments of flap vascularity/viability were performed using laser Doppler spectrophotometry before and after flap elevation.
  
  
  RESULTS
  The normovolemic hemodilution group showed anemia (hemoglobin, 9.5 ± 0.8 g/dl) but less flow occlusion and greater flap survival (72.8 ± 8.6 percent) compared with control (57.4 ± 9.6 percent; p < 0.01) and blood transfusion (62.1 ± 6.5 percent; p < 0.089) groups. In control and blood transfusion groups but not the normovolemic hemodilution group, blood flow was decreased and relative quantity of hemoglobin was increased toward the flap tip, indicating congestion. In control and blood transfusion groups, blood flow and tissue oxygen saturation dropped after flap elevation, but recovered by day 7; congestion gradually improved by day 7.
  
  
  CONCLUSIONS
  The authors determined that congestion promoted necrosis and hemodilution reduced microcirculatory occlusion and increased blood flow and oxygenation in skin flaps. It was suggested that perioperative hemodilution is superior to blood transfusion in any flap operations unless there is a critical systemic need for blood transfusion.
authors.affiliation: Tokyo and Tochigi, Japan.|From the Department of Plastic Surgery, University of Tokyo School of Medicine; and the Department of Plastic Surgery, Jichi Medical University.
authors.forename: Koji
authors.initials: K
authors.lastname: Kanayama
authors.affiliation: Tokyo and Tochigi, Japan.|From the Department of Plastic Surgery, University of Tokyo School of Medicine; and the Department of Plastic Surgery, Jichi Medical University.
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Mineda
authors.affiliation: Tokyo and Tochigi, Japan.|From the Department of Plastic Surgery, University of Tokyo School of Medicine; and the Department of Plastic Surgery, Jichi Medical University.
authors.forename: Takanobu
authors.initials: T
authors.lastname: Mashiko
authors.affiliation: Tokyo and Tochigi, Japan.|From the Department of Plastic Surgery, University of Tokyo School of Medicine; and the Department of Plastic Surgery, Jichi Medical University.
authors.forename: Szu-Hsien
authors.initials: SH
authors.lastname: Wu
authors.affiliation: Tokyo and Tochigi, Japan.|From the Department of Plastic Surgery, University of Tokyo School of Medicine; and the Department of Plastic Surgery, Jichi Medical University.
authors.forename: Jingwei
authors.initials: J
authors.lastname: Feng
authors.affiliation: Tokyo and Tochigi, Japan.|From the Department of Plastic Surgery, University of Tokyo School of Medicine; and the Department of Plastic Surgery, Jichi Medical University.
authors.forename: Kahori
authors.initials: K
authors.lastname: Kinoshita
authors.affiliation: Tokyo and Tochigi, Japan.|From the Department of Plastic Surgery, University of Tokyo School of Medicine; and the Department of Plastic Surgery, Jichi Medical University.
authors.forename: Ataru
authors.initials: A
authors.lastname: Sunaga
authors.affiliation: Tokyo and Tochigi, Japan.|From the Department of Plastic Surgery, University of Tokyo School of Medicine; and the Department of Plastic Surgery, Jichi Medical University.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Yoshimura
mesh_terms: D000818:Animals; D001803:Blood Transfusion; D006438:Hemodilution; D006940:Hyperemia / Q000628:therapy*; D008297:Male; D011183:Postoperative Complications / Q000628:therapy*; D051381:Rats; D017208:Rats, Wistar; D016038:Skin Transplantation; D013524:Surgical Flaps / Q000098:blood supply*