title: Patch incorporation in diaphragmatic hernia.
abstract: OBJECTIVE
  Biomaterial insertion often is required for closure of congenital diaphragmatic hernia (CDH). The optimal biomaterial remains uncertain. This study was designed to compare a commonly used patch (polytetrafluoroethylene) with a recently available fabric, fluorinated polyester. The aim of this study was to determine the clinical performance, histological tissue-polymer interaction, bacterial adhesion, and shrinkage rates of biomaterial inserted endoscopically into a CDH lamb model.
  
  
  METHODS
  Polytetrafluoro-ethylene (PTFE) and fluorinated polyester (FP) were randomised for laparoscopic patch insertion into 12 lambs. All lambs (age <4 weeks) underwent 3-port laparoscopy, surgical creation of diaphragmatic hernia, and sutured patch placement. Two PTFE and 2 FP lambs were killed at 1-, 3-, and 6-month intervals postoperatively. Postmortem examination histopathology, electron microscopy, and specific bacterial broth immersion (Escherichia coil, Staphylococcus aurens, and epidermidis) were performed.
  
  
  RESULTS
  All 12 lambs completed the study with intact patches that were fully peritonised. One abdominal adhesion was noted in a FP lamb at 6 months. FP was comparatively easier to insert, manipulate, and suture endoscopically. Histopathology findings showed that PTFE patches created a strong peripheral foreign body reaction with dystrophic calcification, whereas FP was well incorporated with intrapatch fibroblastic activity and neovascularsation. No significant difference in resistance to bacterial adhesion of relevant organisms was noted between the materials. Graft shrinkage for FP was 7% in one direction only, evident by 3 months.
  
  
  CONCLUSIONS
  Fluorinated polyester has advantages in this laparoscopic lamb model. It shows rapid and sustained incorporation with intrapatch neovascularisation when compared with polytetrafluoro-ethylene's significant foreign body reaction. It was preferred for its endoscopic handling and suturing properties. The laparoscopic techniques used may contribute to the general lack of adhesions, and insufficient data are available to comment on the comparative effect of the materials on adhesion formation. No difference was demonstrated in resistance to bacterial adherence in the harvested materials.
authors.affiliation: Department of Surgery, University of Dundee, Scotland.
authors.forename: C P
authors.initials: CP
authors.lastname: Kimber
authors.forename: M P
authors.initials: MP
authors.lastname: Dunkley
authors.forename: G
authors.initials: G
authors.lastname: Haddock
authors.forename: L
authors.initials: L
authors.lastname: Robertson
authors.forename: F A
authors.initials: FA
authors.lastname: Carey
authors.forename: A
authors.initials: A
authors.lastname: Cuschieri
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D001672:Biocompatible Materials; D005459:Fluorides; D005549:Foreign-Body Reaction / Q000473:pathology; D006548:Hernia, Diaphragmatic / Q000601:surgery*; D065630:Hernias, Diaphragmatic, Congenital; D010535:Laparoscopy; D011091:Polyesters; D011138:Polytetrafluoroethylene; D012756:Sheep; D013526:Surgical Mesh / Q000009:adverse effects / Q000382:microbiology; D000267:Tissue Adhesions; D014945:Wound Healing
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; D011138:Polytetrafluoroethylene; D005459:Fluorides