title: Comparative analysis of frozen and acellularized vascular xenografts.
abstract: BACKGROUND
  We implanted frozen and acellularized porcine xenograft vessels as small-diameter arterial grafts in goats and comparatively analyzed the explanted grafts by gross observation and by light microscopy at predetermined periods.
  
  
  METHODS
  Porcine carotid arteries were harvested and immediately stored within a tissue preservation solution at -70 degrees C in a freezer designated for frozen xenograft vessels. The acellularized xenograft vessels were prepared with NaCl-SDS solution and stored frozen until use. One pair of porcine xenograft vessels were used to compare the frozen and acellularized grafts in the bilateral carotid arteries in one goat. The grafts were implanted for one, 3, and 6 months in three animals. Periodic ultrasonographic examinations were performed during the observation period. Explanted grafts were analyzed by gross observation, and by light microscopy.
  
  
  RESULTS
  All animals survived the experimental procedure without specific problems. Ultrasonographic examinations showed excellent patency in all grafts during the observation period. Gross observations revealed nonthrombotic patent smooth lumens. Microscopic examinations of the explanted grafts showed satisfactory cellular reconstruction to the 6-month stage. Although more inflammatory responses were observed in the early phase of implantation of frozen xenografts than of acellularized xenografts, there was no evidence of significant rejection of the frozen xenografts.
  
  
  CONCLUSIONS
  These findings suggest that porcine vessel xenografts, regardless of them being acellularized or simply frozen xenografts, can be acceptably implanted in goats as a form of small-diameter vascular graft.
authors.affiliation: Department of Thoracic & Cardiovascular Surgery, College of Medicine, Seoul National University Hospital, Yongon-Dong 28, Chongro-Gu, Seoul 110-744, Korea. wongon@plaza.snu.ac.kr
authors.forename: W G
authors.initials: WG
authors.lastname: Kim
authors.forename: J W
authors.initials: JW
authors.lastname: Seo
authors.forename: J H
authors.initials: JH
authors.lastname: Yang
mesh_terms: D000818:Animals; D002339:Carotid Arteries / Q000166:cytology* / Q000637:transplantation*; D015925:Cryopreservation; D006041:Goats; D006085:Graft Survival; D008853:Microscopy; D013552:Swine; D014183:Transplantation, Heterologous; D014654:Vascular Patency