title: Vascular endothelium growth factor, surgical delay, and skin flap survival.
abstract: OBJECTIVE
  Cytokines may be a mechanism by which surgical delay can increase flap survival. We previously found that preoperative vascular endothelium growth factor (VEGF) administration in the rat transverse rectus abdominis myocutaneous (TRAM) flap could improve skin paddle survival. In this study, we used partial elevation of the rat TRAM flap as a surgical delay to assess endogenous cytokine expression and tissue survival comparable to undelayed TRAM flaps.
  
  
  METHODS
  In Part I, TRAM flaps underwent surgical delay procedures; 7 days later, the flaps were completely elevated and reinset. At the same time, other flaps were raised and reinset without delay. Skin paddle survival in both groups was evaluated at 7 days. In Part II, skin biopsies from TRAM zones I to IV were taken at the time of delay and at intervals of 12, 24, 48, and 72 hours. Specimens were assessed for selected cytokine gene expression by reverse transcription-polymerase chain reaction analysis (TR-PCR).
  
  
  RESULTS
  Surgical delay significantly (P < 0.001) increased skin paddle survival in the delayed TRAM flaps (16.14 +/- 1.53 cm, 81.9%) compared with undelayed flaps (7.68 +/- 3.16 cm, 40.9%). TGF-beta and PDGF expressions were not changed by surgical delay, but basic fibroblast growth factor (bFGF) and VEGF expressions increased significantly (P < 0.05 and P < 0.01) after delay.
  
  
  CONCLUSIONS
  In the rat TRAM model, surgical delay resulted in increased VEGF expression and increased skin paddle survival. These results correlate with previous studies showing the preoperative injection of VEGF increases skin paddle survival. VEGF may be an important element in the delay phenomenon and may be an agent for pharmacological delay.
authors.affiliation: Division of Plastic Surgery, University of Mississippi Medical Center, Jackson, Mississippi, USA. wlineaweaver@surgery.umsmed.edu
authors.forename: William C
authors.initials: WC
authors.lastname: Lineaweaver
authors.forename: Man-Ping
authors.initials: MP
authors.lastname: Lei
authors.forename: William
authors.initials: W
authors.lastname: Mustain
authors.forename: Tanya M
authors.initials: TM
authors.lastname: Oswald
authors.forename: Dongmei
authors.initials: D
authors.lastname: Cui
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001707:Biopsy, Needle; D004195:Disease Models, Animal; D006085:Graft Survival / Q000187:drug effects; D007150:Immunohistochemistry; D008297:Male; D011336:Probability; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017568:Rectus Abdominis / Q000637:transplantation*; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013524:Surgical Flaps / Q000473:pathology*; D013997:Time Factors; D016378:Tissue Transplantation / Q000009:adverse effects / Q000379:methods; D042442:Vascular Endothelial Growth Factors / Q000494:pharmacology*
chemical_list: D012333:RNA, Messenger; D042442:Vascular Endothelial Growth Factors