title: A comparative study of bovine and porcine pericardium to highlight their potential advantages to manufacture percutaneous cardiovascular implants.
abstract: BACKGROUND
  Prosthetic heart valves designed to be implanted percutaneously must be loaded within delivery catheters whose diameter can be as low as 18 F (6 mm). This mandatory crimping of the devices may result in deleterious damages to the tissues used for valve manufacturing. As bovine and porcine pericardial tissue are currently given preference because of their excellent availability and traceability, a preliminary comparative study was undertaken to highlight their potential advantages.
  
  
  METHODS
  Bovine and pericardium patches were compared morphologically (light microscopy, scanning electron microscopy and transmission electron microscopy). The acute thrombogenicity of both materials was measured in term of platelet uptake and observed by scanning electron microscopy, porcine intact and injured arteries being used as controls. The pericardium specimens were also subjected to uniaxial tensile tests to compare their respective mechanical characteristics.
  
  
  RESULTS
  Both pericardiums showed a layered architecture of collagen bundles presenting some interstitial cells. They displayed wavy crimps typical of an unloaded collagenous tissue. The collagen bundles were not bound together and the fibrils were parallel with characteristic periodicity patterns of cross striations. The mesothelial cells found in vivo on the serous surface were no longer present due to tissue processing, but the adjacent structure was far more compacted when compared to the fibrous side. The fibrinocollagenous surfaces were found to be more thrombogenic for both bovine and porcine tissues and the serous side of the porcine pericardium retained more platelets when compared to the bovine samples, making the acute thrombogenicity more important in the porcine pericardium.
  
  
  CONCLUSIONS
  Both bovine and porcine pericardium used in cardiovascular implantology can be selected to manufacture percutaneous heart valves. The selection of one pericardium preferably to the other should deserve additional testing regarding the innocuousness of crimping when loaded in delivery catheters and the long-term durability after percutaneous deployment.
authors.affiliation: 1Center of LOEX, Laval University, Quebec (QC), Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Gauvin
authors.forename: Georgi
authors.initials: G
authors.lastname: Marinov
authors.forename: Yayhe
authors.initials: Y
authors.lastname: Mehri
authors.forename: Julianne
authors.initials: J
authors.lastname: Klein
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.forename: Danielle
authors.initials: D
authors.lastname: Larouche
authors.forename: Randolph
authors.initials: R
authors.lastname: Guzman
authors.forename: Ze
authors.initials: Z
authors.lastname: Zhang
authors.forename: Lucie
authors.initials: L
authors.lastname: Germain
authors.forename: Robert
authors.initials: R
authors.lastname: Guidoin
mesh_terms: D000818:Animals; D002417:Cattle; D006350:Heart Valve Prosthesis; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010496:Pericardium / Q000033:anatomy & histology*; D013552:Swine
keywords: Porcine pericardium; bioprostheses; bovine pericardium; heart valves; percutaneous valves