title: Does treatment of split-thickness skin grafts with negative-pressure wound therapy improve tissue markers of wound healing in a porcine experimental model?
abstract: BACKGROUND
  Negative-pressure wound therapy (NPWT) has been used for to treat wounds for more than 15 years and, more recently, has been used to secure split-thickness skin grafts. There are some data to support this use of NPWT, but the actual mechanism by which NPWT speeds healing or improves skin graft take is not entirely known. The purpose of this project was to assess whether NPWT improved angiogenesis, wound healing, or graft survival when compared with traditional bolster dressings securing split-thickness skin grafts in a porcine model.
  
  
  METHODS
  We performed two split-thickness skin grafts on each of eight 30 kg Yorkshire pigs. We took graft biopsies on postoperative days 2, 4, 6, 8, and 10 and submitted the samples for immunohistochemical staining, as well as standard hematoxylin and eosin staining. We measured the degree of vascular ingrowth via immunohistochemical staining for von Willenbrand's factor to better identify blood vessel epithelium. We determined the mean cross-sectional area of blood vessels present for each representative specimen, and then compared the bolster and NPWT samples. We also assessed each graft for incorporation and survival at postoperative day 10.
  
  
  RESULTS
  Our analysis of the data revealed that there was no statistically significant difference in the degree of vascular ingrowth as measured by mean cross-sectional capillary area (p = 0.23). We did not note any difference in graft survival or apparent incorporation on a macroscopic level, although standard hematoxylin and eosin staining indicated that microscopically, there seemed to be better subjective graft incorporation in the NPWT samples and a nonsignificant trend toward improved graft survival in the NPWT group.
  
  
  CONCLUSIONS
  We were unable to demonstrate a significant difference in vessel ingrowth when comparing NPWT and traditional bolster methods for split-thickness skin graft fixation. More studies are needed to elucidate the manner by which NPWT exerts its effects and the true clinical magnitude of these effects.
authors: Department of Surgery, Maine Medical Center, Portland 04102, USA. wardc1@mmc.org
authors: Christopher
authors: C
authors: Ward
authors: David
authors: D
authors: Ciraulo
authors: Michael
authors: M
authors: Coulter
authors: Steven
authors: S
authors: Desjardins
authors: Lucy
authors: L
authors: Liaw
authors: Sarah
authors: S
authors: Peterson
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001458:Bandages; D015415:Biomarkers / Q000032:analysis; D001707:Biopsy, Needle; D062109:Dermatologic Surgical Procedures; D004195:Disease Models, Animal; D006084:Graft Rejection; D006085:Graft Survival; D007150:Immunohistochemistry; D018919:Neovascularization, Physiologic / Q000502:physiology*; D011897:Random Allocation; D012016:Reference Values; D012867:Skin / Q000473:pathology; D016038:Skin Transplantation / Q000009:adverse effects / Q000379:methods*; D034421:Sus scrofa; D013552:Swine; D014945:Wound Healing / Q000502:physiology*; D014841:von Willebrand Factor / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D014841:von Willebrand Factor