title: Prevention of postoperative pericardial adhesions with a novel regenerative collagen sheet.
abstract: BACKGROUND
  Postoperative pericardial adhesions make a repeat sternotomy time-consuming and dangerous. The purpose of this study was to evaluate the efficacy of a new collagen pericardial substitute for preventing postoperative pericardial adhesions.
  
  
  METHODS
  Our absorbable substitute consists of three layers: a middle layer of aterocollagen between two layers of sodium hyaluronic acid and aterocollagen. In experiment 1 in this study, the patch, made of 9,000 filaments of aterocollagen fibers, (group 1; n = 5) was compared with a patch made of 6,000 filaments (group 2; n = 7), an expanded polytetrafluoroethylene sheet (group 3; n = 6), and a control group (group 4; n = 4). Subsequently, in experiment 2, the patch was examined at 4 weeks (n = 5), 12 weeks (n = 5), and 24 weeks (n = 4) after the operation by light microscopy and scanning electron microscopy.
  
  
  RESULTS
  The area of adhesion in group 1 was significantly less as compared with that in the other three groups, and the coronary vessels were clearly identifiable; on the other hand, all the animals in the control group showed moderate to severe adhesions, and the coronary vessels were completely obscured. In experiment 2, formation of a membranous tissue resembling the native pericardial membrane was observed in all animals, and the thickness of this membrane showed a marked increase by 24 weeks after the operation. Light microscopy and scanning electron microscopy also showed the formation of a mesothelium-like lining.
  
  
  CONCLUSIONS
  The new absorbable and regenerative collagen patch seemed to be biocompatible, and its use was associated with minimal adhesion formation and preserved coronary anatomy.
authors.affiliation: Department of Cardiothoracic Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsukihara
authors.forename: Shinichi
authors.initials: S
authors.lastname: Takamoto
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kitahori
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Matsuda
authors.forename: Arata
authors.initials: A
authors.lastname: Murakami
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Novick
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Suematsu
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D006348:Cardiac Surgical Procedures; D003094:Collagen / Q000627:therapeutic use*; D004285:Dogs; D006331:Heart Diseases / Q000517:prevention & control*; D010496:Pericardium / Q000473:pathology*; D011183:Postoperative Complications / Q000517:prevention & control*; D019919:Prosthesis Implantation; D000267:Tissue Adhesions / Q000517:prevention & control
chemical_list: D001672:Biocompatible Materials; D003094:Collagen