title: Comparison of AlloDerm and AlloMax tissue incorporation in rats.
abstract: BACKGROUND
  Human acellular dermal matrices (HADMs) are used in a variety of settings. AlloMax is a new HADM currently being used for breast reconstruction and hernia repair. We compared the in vivo tissue integration of AlloMax to AlloDerm, a well-studied HADM, in rats.
  
  
  METHODS
  We implanted AlloDerm and AlloMax patches into subcutaneous pockets on the backs of 32 male Sprague-Dawley rats. The animals were killed after either 4 or 8 weeks, and the patches were recovered and stained for histopathologic analyses. Microscopic end points included patch thickness, vascularization, tissue in-growth, fibroblast proliferation, and inflammation.
  
  
  RESULTS
  All animals completed the study without complications or infection. There were no significant differences in graft thicknesses at 4 and 8 weeks. Microscopically, at 4 weeks, AlloDerm sections had significantly more microvessels than AlloMax (P = 0.02). This disparity increased by 8 weeks (P < 0.01). Similarly, we found greater tissue in-growth and fibroblast proliferation in AlloDerm than AlloMax sections at 4 (P < 0.01) and at 8 (P < 0.01) weeks. Inflammatory infiltrates consisted of lymphocytes, histiocytes, eosinophils, and plasma cells. Deep graft infiltration by predominately lymphocytic inflammatory cells was significantly higher in AlloDerm than AlloMax grafts at 4 (P = 0.01) and 8 (P = 0.02) weeks. Graft necrosis was uncommon, but marginal fibrosis was similar in both.
  
  
  CONCLUSIONS
  AlloDerm grafts had greater neovascularization, tissue infiltration, fibroblast proliferation, and inflammatory reaction than AlloMax grafts when placed subcutaneously in rats. AlloDerm may be better incorporated than AlloMax when placed in vivo.
authors: From the *Department of Surgery, †Department of Pathology, and ‡Clinical Investigation Facility, David Grant USAF Medical Center, Travis AFB, CA; and §Division of Plastic Surgery, UC Davis School of Medicine, Sacramento, CA.
authors: Matthew V
authors: MV
authors: Chauviere
authors: Ryan J
authors: RJ
authors: Schutter
authors: Megan B
authors: MB
authors: Steigelman
authors: Beth Z
authors: BZ
authors: Clark
authors: John Kevin
authors: JK
authors: Grayson
authors: David E
authors: DE
authors: Sahar
mesh_terms: D062088:Acellular Dermis; D000818:Animals; D001672:Biocompatible Materials; D003094:Collagen; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: C440568:Alloderm; D001672:Biocompatible Materials; D003094:Collagen