title: Bacterial clearance of biologic grafts used in hernia repair: an experimental study.
abstract: BACKGROUND
  Biologic grafts used in ventral hernia repair are derived from various sources and undergo different post-tissue-harvesting processing, handling, and sterilization techniques. It is unclear how these various characteristics impact graft response in the setting of contamination. We evaluated four materials in an infected hernia repair animal model using fluorescence imaging and quantitative culture studies.
  
  
  METHODS
  One hundred seven rats underwent creation of a chronic hernia. They were then repaired with one synthetic polyester control material (n = 12) and four different biologic grafts (n = 24 per material). Biologic grafts evaluated included Surgisis (porcine small intestinal submucosa), Permacol (crosslinked porcine dermis), Xenmatrix (noncrosslinked porcine dermis), and Strattice (noncrosslinked porcine dermis). Half of the repairs in each group were inoculated with Staphylococcus aureus at 10(4) CFU/ml and survived for 30 days without systemic antibiotics. Animals then underwent fluorescence imaging and quantitative bacterial studies.
  
  
  RESULTS
  All clean repairs remained sterile. Rates of bacterial clearance were as follows: polyester synthetic 0%, Surgisis 58%, Permacol 67%, Xenmatrix 75%, and Strattice 92% (P=0.003). Quantitative bacterial counts had a similar trend in bacterial clearance: polyester synthetic 1×10(6) CFU/g, Surgisis 4.3×10(5) CFU/g, Permacol 1.7×10(3) CFU/g, Xenmatrix 46 CFU/g, and Strattice 31 CFU/g (P=0.001). Fluorescence imaging was unable to detect low bacterial fluorescence counts observed on bacterial studies.
  
  
  CONCLUSIONS
  Biologic grafts, in comparison to synthetic material, are able to clear a Staphylococcus aureus contamination; however, they are able to do so at different rates. Bacterial clearance correlated to the level of residual bacterial burden observed in our study. Post-tissue-harvesting processing, handling, and sterilization techniques may contribute to this observed difference in ability to clear bacteria.
authors.affiliation: Department of Surgery, University Hospitals Case Medical Center, and Department of Biomedical Engineering, Case Western Reserve School of Medicine, 11100 Euclid Avenue, Cleveland, OH 44106-5047, USA.
authors.forename: K C
authors.initials: KC
authors.lastname: Harth
authors.forename: A-M
authors.initials: AM
authors.lastname: Broome
authors.forename: M R
authors.initials: MR
authors.lastname: Jacobs
authors.forename: J A
authors.initials: JA
authors.lastname: Blatnik
authors.forename: F
authors.initials: F
authors.lastname: Zeinali
authors.forename: S
authors.initials: S
authors.lastname: Bajaksouzian
authors.forename: M J
authors.initials: MJ
authors.lastname: Rosen
mesh_terms: D000818:Animals; D058491:Bacterial Load; D001705:Bioprosthesis / Q000382:microbiology*; D003094:Collagen; D004195:Disease Models, Animal; D004866:Equipment Contamination; D005260:Female; D046449:Hernia, Abdominal / Q000382:microbiology / Q000601:surgery*; D008856:Microscopy, Fluorescence; D011091:Polyesters; D051381:Rats; D017207:Rats, Sprague-Dawley; D018709:Statistics, Nonparametric; D013552:Swine
chemical_list: C422414:Permacol; D011091:Polyesters; D003094:Collagen