title: Three-layered synthetic pericardial substitutes reduce postoperative pericardial adhesions.
abstract: BACKGROUND
  The development of postoperative pericardial adhesions increases the risk of cardiac reoperations. The purpose of this study was to test a new pericardial substitute (UBE sheet; UBE Industries, Ltd, Tokyo, Japan) that consists of 3 layers, namely, a middle layer of polyester inserted between 2 layers of silicone-urethane copolymer.
  
  
  METHODS
  Before implantation into the animals, platelet adhesion to the UBE sheet was evaluated in vitro. In the canine model, the UBE sheet (group I; n = 6) was implanted for 3 months. The development of adhesions, epicardial reactions, the shrink ratio of the patch, and macrophage infiltration to the epicardium with histologic examination were evaluated. As a control, an expanded polytetrafluoroethylene sheet (group II; n = 5) was implanted in the same manner.
  
  
  RESULTS
  Scanning electron microscopy of the platelets adhered to the sheet showed that the UBE sheet was superior in biocompatibility compared with the expanded polytetrafluoroethylene sheet. In the canine study, group I showed fewer adhesions than group II (median [25th percentile, 75th percentile]: 0.0 [0.0, 0.0] vs 1.0 [1.0, 2.3]; P = .003; Mann-Whitney U test), fewer epicardial reactions (1.75 [1.0, 3.0] vs 3.0 [3.0, 3.0]; P = .034), and a smaller shrink ratio (8.0% [5.5%, 12.4%] vs 31.7% [30.0%, 44.8%]; P = .006). Immunohistologic studies showed fewer macrophage infiltrations (86 [56.8, 139.3] vs 201 [161.0, 276.5] in 3 fields; P = .045) into the epicardium of group I.
  
  
  CONCLUSIONS
  The new 3-layered pericardial substitute clearly reduced adhesion formation. We concluded that this sheet may cause fewer adhesions and a less severe inflammatory reaction after cardiac surgery, thereby facilitating safe adhesiolysis reoperation.
authors.affiliation: Department of Cardiovascular Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Kajihara
authors.forename: Masataka
authors.initials: M
authors.lastname: Eto
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Oishi
authors.forename: Noriko
authors.initials: N
authors.lastname: Boku
authors.forename: Kunio
authors.initials: K
authors.lastname: Kuwahara
authors.forename: Naoki
authors.initials: N
authors.lastname: Nishiguchi
authors.forename: Chikara
authors.initials: C
authors.lastname: Kotani
authors.forename: Shigeki
authors.initials: S
authors.lastname: Morita
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001705:Bioprosthesis; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000379:methods; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D008422:Materials Testing; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D010496:Pericardium / Q000473:pathology* / Q000601:surgery*; D011093:Polyethylene Terephthalates / Q000737:chemistry*; D011138:Polytetrafluoroethylene / Q000737:chemistry*; D011183:Postoperative Complications / Q000517:prevention & control; D011897:Random Allocation; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D000267:Tissue Adhesions / Q000517:prevention & control*
chemical_list: D001672:Biocompatible Materials; D008567:Membranes, Artificial; D011093:Polyethylene Terephthalates; D011138:Polytetrafluoroethylene