title: Impaired laparotomy wound healing in obese rats.
abstract: BACKGROUND
  Obesity increases the risk of laparotomy dehiscence and incisional hernia. The aim of this study was to measure the biological effect of obesity on laparotomy wound healing and the formation of incisional hernias.
  
  
  METHODS
  Normal-weight Sprague-Dawley (SD) and obese Zucker rats were used in an established laparotomy wound healing and incisional ventral hernia model. Mechanical testing was performed on abdominal wall strips collected from laparotomy wounds. Hernia size was measured by digital imaging. Picrosirius staining for collagen isoforms was observed with polarized microscopy. Abdominal wall fibroblasts were cultured to measure collagen matrix remodeling and proliferation.
  
  
  RESULTS
  Laparotomy wound healing was significantly impaired in obese rats. Mechanical strength was lower than in normal-weight rats. Yield load was reduced in the obese group at all time points. Picrosirius red staining showed increased immature type III collagen content and disorganized type I collagen fibers within laparotomy wounds of obese rats. Wound size was significantly larger in the obese group. Collagen matrix remodeling was impaired with fibroblasts from obese rats, but there was no difference in fibroblast proliferation between the obese and normal-weight groups.
  
  
  CONCLUSIONS
  We observed for the first time that laparotomy wound healing is impaired in obese rats. The recovery of laparotomy wound strength is delayed due to abnormal collagen maturation and remodeling, possibly due to a defect in fibroblast function. Strategies to improve outcomes for laparotomy wound healing in obese patients should include correcting the wound healing defect, possibly with growth factor or cell therapy.
authors.affiliation: Department of Surgery, University of Michigan, 2124F Taubman Center, 1500 East Medical Center Drive, Ann Arbor, MI 48109-0331, USA.
authors.forename: Liyu
authors.initials: L
authors.lastname: Xing
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Culbertson
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wen
authors.forename: Martin C
authors.initials: MC
authors.lastname: Robson
authors.forename: Michael George
authors.initials: MG
authors.lastname: Franz
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D007813:Laparotomy; D009765:Obesity / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011924:Rats, Zucker; D013997:Time Factors; D014945:Wound Healing