title: Comparative analysis of histopathologic effects of synthetic meshes based on material, weight, and pore size in mice.
abstract: BACKGROUND
  While synthetic prosthetics have essentially become mandatory for hernia repair, mesh-induced chronic inflammation and scarring can lead to chronic pain and limited mobility. Mesh propensity to induce such adverse effects is likely related to the prosthetic's material, weight, and/or pore size. We aimed to compare histopathologic responses to various synthetic meshes after short- and long-term implantations in mice.
  
  
  METHODS
  Samples of macroporous polyester (Parietex [PX]), heavyweight microporous polypropylene (Trelex[TX]), midweight microporous polypropylene (ProLite[PL]), lightweight macroporous polypropylene (Ultrapro[UP]), and expanded polytetrafluoroethylene (DualMesh[DM]) were implanted subcutaneously in mice. Four and 12 wk post-implantation, meshes were assessed for inflammation, foreign body reaction (FBR), and fibrosis.
  
  
  RESULTS
  All meshes induced varying levels of inflammatory responses. PX induced the greatest inflammatory response and marked FBR. DM induced moderate FBR and a strong fibrotic response with mesh encapsulation at 12 wk. UP and PL had the lowest FBR, however, UP induced a significant chronic inflammatory response. Although inflammation decreased slightly for TX, marked FBR was present throughout the study. Of the three polypropylene meshes, fibrosis was greatest for TX and slightly reduced for PL and UP. For UP and PL, there was limited fibrosis within each mesh pore.
  
  
  CONCLUSIONS
  Polyester mesh induced the greatest FBR and lasting chronic inflammatory response. Likewise, marked fibrosis and encapsulation was seen surrounding ePTFE. Heavier polypropylene meshes displayed greater early and persistent fibrosis; the reduced-weight polypropylene meshes were associated with the least amount of fibrosis. Mesh pore size was inversely proportional to bridging fibrosis. Moreover, reduced-weight polypropylene meshes demonstrated the smallest FBR throughout the study. Overall, we demonstrated that macroporous, reduced-weight polypropylene mesh exhibited the highest degree of biocompatibility at sites of mesh implantation.
authors.affiliation: Department of Surgery, University of Connecticut Health Center, Farmington, Connecticut, USA.
authors.forename: Sean B
authors.initials: SB
authors.lastname: Orenstein
authors.forename: Ean R
authors.initials: ER
authors.lastname: Saberski
authors.forename: Donald L
authors.initials: DL
authors.lastname: Kreutzer
authors.forename: Yuri W
authors.initials: YW
authors.lastname: Novitsky
mesh_terms: D000818:Animals; D062109:Dermatologic Surgical Procedures; D004195:Disease Models, Animal; D005355:Fibrosis / Q000209:etiology / Q000473:pathology; D005549:Foreign-Body Reaction / Q000209:etiology* / Q000473:pathology; D059685:Herniorrhaphy / Q000295:instrumentation* / Q000379:methods; D008422:Materials Testing / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D011091:Polyesters / Q000009:adverse effects / Q000737:chemistry; D011126:Polypropylenes / Q000009:adverse effects / Q000737:chemistry; D011138:Polytetrafluoroethylene / Q000009:adverse effects / Q000737:chemistry; D011183:Postoperative Complications / Q000209:etiology; D012867:Skin / Q000473:pathology*; D013526:Surgical Mesh / Q000009:adverse effects*
chemical_list: D011091:Polyesters; D011126:Polypropylenes; D011138:Polytetrafluoroethylene