title: Differences in polypropylene shrinkage depending on mesh position in an experimental study.
abstract: BACKGROUND
  Polypropylene (PP) mesh is one of the most frequent materials used in hernia repair. We have experimentally evaluated the shrinkage of PP mesh depending on the place of implantation.
  
  
  METHODS
  In 15 New Zealand rabbits a muscular defect measuring 3 x 3 cm was created in both pararectal sides of the abdominal wall. The defect was repaired using a PP mesh measuring 5 x 3.5 cm that was placed in the right side in the sublay location and in the left side in the onlay location. Five animals were killed on the 30th, 60th, and 90th postoperative days. Macroscopic measurement and microscopic study of the prosthesis-host tissue interfaces were performed.
  
  
  RESULTS
  One rabbit was killed because of severe infection in the onlay mesh. Another 2 infections were tolerated in the onlay mesh side. All the prostheses were integrated in the host tissue at death. In the macroscopic evaluation the mesh areas were reduced by 25.92% on the 30th day, by 28.67% on the 60th day, and by 29.02% on the 90th day. The mesh shrinkage was greater in the onlay group than in the sublay group at the 3 time intervals. More inflammatory leukocyte and mononuclear responses also were seen in the onlay group.
  
  
  CONCLUSIONS
  These observations support the theory of PP mesh shrinkage as a consequence of the incorporation of the biomaterial to the scarring tissue. This shrinkage is significantly more intense if the meshes are placed in the onlay position.
authors: Department of Surgery, Cadiz University School of Medicine, Cra Nacional IV, Km 665, 11510 Puerto Real, Spain. mgarciau@meditex.es
authors: Miguel Angel
authors: MA
authors: García-Ureña
authors: Vicente
authors: V
authors: Vega Ruiz
authors: Antonio
authors: A
authors: Díaz Godoy
authors: Jose María
authors: JM
authors: Báez Perea
authors: Luis Miguel
authors: LM
authors: Marín Gómez
authors: Francisco Javier
authors: FJ
authors: Carnero Hernández
authors: Miguel Angel
authors: MA
authors: Velasco García
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D005260:Female; D046449:Hernia, Abdominal / Q000601:surgery*; D008422:Materials Testing; D011126:Polypropylenes / Q000494:pharmacology*; D011817:Rabbits; D013526:Surgical Mesh; D014945:Wound Healing
chemical_list: D001672:Biocompatible Materials; D011126:Polypropylenes