title: Experimental Rat Skin Flap Model That Distinguishes between Venous Congestion and Arterial Ischemia: The Reverse U-Shaped Bipedicled Superficial Inferior Epigastric Artery and Venous System Flap.
abstract: BACKGROUND
  The commonly used flap models have drawbacks that limit their usefulness. In the random skin flap model, flap necrosis is caused by both arterial and venous insufficiency. In the axial skin flap model, flap viability is easily affected by the pedicle blood flow and can result in complete necrosis. This study aimed to establish a new rat skin flap model that has a consistent flap survival rate and in which venous congestion and arterial ischemia can be readily distinguished macroscopically.
  
  
  METHODS
  Rats underwent reverse U-shaped bipedicled superficial epigastric artery flap elevation. The right superficial epigastric vessels formed the pedicle. In the control rats (n = 3), the left superficial epigastric vessels were left intact. In the ischemia group (n = 10), the left superficial epigastric artery was ligated. In the congestion group (n = 10), the left superficial epigastric vein was ligated. The flap was returned to the original site and sutured. The surrounding neovascularization was blocked by polyurethane film. Flap survival rates were evaluated on postoperative day 3.
  
  
  RESULTS
  The flaps in the ischemia and congestion groups were noticeably pale and violet, respectively. Flap necrosis was noted in the contralateral distal zone only. It started on postoperative day 2 in the ischemia and congestion groups. The mean flap survival rates of the control, ischemia, and congestion groups were 100 percent, 61.8 percent (range, 56.9 to 67.1 percent), and 42.3 percent (35.7 to 48.7 percent), respectively (all p < 0.001).
  
  
  CONCLUSIONS
  The flap facilitated discrimination of the effects of ischemia and congestion. This new rat skin flap model is simple and easy to construct, and has a consistent flap survival rate.
authors.affiliation: Tokyo, Japan.|From the Department of Plastic, Reconstructive, and Aesthetic Surgery, Nippon Medical School; and the Department of Pathology and the Department of Integrated Diagnostic Pathology, Graduate School of Medicine, Nippon Medical School Hospital.
authors.forename: Noriko M
authors.initials: NM
authors.lastname: Matsumoto
authors.affiliation: Tokyo, Japan.|From the Department of Plastic, Reconstructive, and Aesthetic Surgery, Nippon Medical School; and the Department of Pathology and the Department of Integrated Diagnostic Pathology, Graduate School of Medicine, Nippon Medical School Hospital.
authors.forename: Masayo
authors.initials: M
authors.lastname: Aoki
authors.affiliation: Tokyo, Japan.|From the Department of Plastic, Reconstructive, and Aesthetic Surgery, Nippon Medical School; and the Department of Pathology and the Department of Integrated Diagnostic Pathology, Graduate School of Medicine, Nippon Medical School Hospital.
authors.forename: Junichi
authors.initials: J
authors.lastname: Nakao
authors.affiliation: Tokyo, Japan.|From the Department of Plastic, Reconstructive, and Aesthetic Surgery, Nippon Medical School; and the Department of Pathology and the Department of Integrated Diagnostic Pathology, Graduate School of Medicine, Nippon Medical School Hospital.
authors.forename: Wei-Xia
authors.initials: WX
authors.lastname: Peng
authors.affiliation: Tokyo, Japan.|From the Department of Plastic, Reconstructive, and Aesthetic Surgery, Nippon Medical School; and the Department of Pathology and the Department of Integrated Diagnostic Pathology, Graduate School of Medicine, Nippon Medical School Hospital.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Takami
authors.affiliation: Tokyo, Japan.|From the Department of Plastic, Reconstructive, and Aesthetic Surgery, Nippon Medical School; and the Department of Pathology and the Department of Integrated Diagnostic Pathology, Graduate School of Medicine, Nippon Medical School Hospital.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Umezawa
authors.affiliation: Tokyo, Japan.|From the Department of Plastic, Reconstructive, and Aesthetic Surgery, Nippon Medical School; and the Department of Pathology and the Department of Integrated Diagnostic Pathology, Graduate School of Medicine, Nippon Medical School Hospital.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Akaishi
authors.affiliation: Tokyo, Japan.|From the Department of Plastic, Reconstructive, and Aesthetic Surgery, Nippon Medical School; and the Department of Pathology and the Department of Integrated Diagnostic Pathology, Graduate School of Medicine, Nippon Medical School Hospital.
authors.forename: Ryuji
authors.initials: R
authors.lastname: Ohashi
authors.affiliation: Tokyo, Japan.|From the Department of Plastic, Reconstructive, and Aesthetic Surgery, Nippon Medical School; and the Department of Pathology and the Department of Integrated Diagnostic Pathology, Graduate School of Medicine, Nippon Medical School Hospital.
authors.forename: Zenya
authors.initials: Z
authors.lastname: Naito
authors.affiliation: Tokyo, Japan.|From the Department of Plastic, Reconstructive, and Aesthetic Surgery, Nippon Medical School; and the Department of Pathology and the Department of Integrated Diagnostic Pathology, Graduate School of Medicine, Nippon Medical School Hospital.
authors.forename: Rei
authors.initials: R
authors.lastname: Ogawa
mesh_terms: D000818:Animals; D001158:Arteries / Q000473:pathology*; D019074:Epigastric Arteries; D058752:Free Tissue Flaps; D006940:Hyperemia / Q000473:pathology*; D007511:Ischemia / Q000473:pathology*; D008297:Male; D023421:Models, Animal; D051381:Rats; D011916:Rats, Inbred F344; D012867:Skin / Q000098:blood supply*