Aortic valve grafts in the rat: Evidence for rejection

Moustapha, Ahmad; Ross, David B.; Bittira, Bindu; Van-Velzen, Dick; McAlister, Vivian C.; Lannon, Christopher L.; Lee, Timothy D.

doi:10.1016/s0022-5223(97)70002-3

Cited by 29 publications

(22 citation statements)

References 18 publications

(5 reference statements)

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“…17 Fresh allogeneic valve grafts have been shown to have significant tissue infiltration at 7 days (Figure 2g), loss of leaflet cellularity by 14 days (Figure 2h), and loss of structural integrity by 28 days (Figure 2i). Morphologically, the mode of failure appears to be similar for fresh allogeneic and cryopreserved syngeneic grafts; in both cases, the end result was early structural failure by 28 days with complete destruction of the implanted valve (Figures 2f and 2i).…”

Section: Resultsmentioning

confidence: 97%

“…Structural failure of leaflets in an allogeneic environment with fresh valve grafts has been described in previous work performed by us and others. 17,19 Based on this observation, it appears that injury to leaflet stromal cells, whether immune mediated (allogeneic/T cell driven) or mechanical (syngeneic cryopreserved tissue/monocyte macrophage driven), will result in tissue infiltration and the loss of structural integrity. In the present study, cryopreservation resulted in early infiltration of a significant number of mononuclear cells (ED1 ϩ ), which are known to be important early effector cells in response to injury and to initiate a response to injury process.…”

Section: Discussionmentioning

confidence: 99%

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Cryopreservation of Rat Aortic Valves Results in Increased Structural Failure

Légaré

Lee²

2000

Circulation

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Background-The cause of valve allograft failure is most likely multifactorial and may include mechanical, immunological, and other factors. Cryopreservation of these valves is often used to extend storage times. However, there has been considerable confusion as to the effects of cryopreservation on valve durability. Our objective was to determine the effects of cryopreservation on histopathological changes in rat aortic valve grafts. Methods and Results-Syngeneic rat aortic valve grafts (Lewis to Lewis; nϭ24) and allogeneic rat aortic valve grafts (Brown Norway to Lewis; nϭ24) were implanted infrarenally, either fresh or after cryopreservation. At 7, 14, and 28 days, the valves were explanted, and histological and immunohistochemical examinations were performed in a blinded fashion. Fresh syngeneic graft leaflets retained their normal structure for the 28-day period of observation. Cryopreserved syngeneic grafts showed retrovalvar thrombus formation, with leaflet destruction at 7, 14, and 28 days. Fresh allogeneic graft leaflets showed significant leaflet thickening and progressive destruction at 14 and 28 days. Cryopreserved allogeneic grafts had evidence of retrovalvar thrombus formation with leaflet destruction at 7, 14, and 28 days. Cryopreserved syngeneic grafts resulted in significant infiltration of mononuclear (ED1 ϩ ) cells not seen with fresh syngeneic grafts but similar to fresh allogeneic grafts. All allogeneic grafts resulted in significant infiltration of T-lymphocytes (CD3 ϩ , CD8 ϩ , CD43 ϩ ). Conclusions-Cryopreservation appears to predispose syngeneic and allogeneic rat aortic valve leaflets to accelerated injury and destruction.

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Section: Resultsmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

Cryopreservation of Rat Aortic Valves Results in Increased Structural Failure

Légaré

Lee²

2000

Circulation

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“…Kouwenhoven et al demonstrated that ischemic time and surgical trauma are immune-independent factors causing intimal thickening [16]. Histological evaluation of syngeneic valve grafts using earlier techniques revealed unexplained intimal proliferation [11]. Using our implantation model we did not see this intimal thickening in the syngeneic grafts at Day 21, which may indicate reduction of the nonimmunological factors.…”

Section: Discussionmentioning

confidence: 56%

“…The observed histological abnormalities-severe perivascular infiltration of mononuclear cells, malformation of the leaflet, and presence of thrombi in the sinus of Valsalva-strongly suggest such a process [11]. Using aortic vascular grafts in the same WAG-to-BN combination Geerlings et al also demonstrated histological aberrations in the vascular wall 21 days after transplantation, which they interpreted as histological signs of rejection [18].…”

Section: Discussionmentioning

confidence: 97%

“…A number of studies have demonstrated both humoral and cellular donor-specific immune response after aortic valve implantation in young and adult recipients [8 -10]. Recent histological studies on allogeneic heart valves, explanted early or late after implantation, showed signs of both acute and chronic rejection [11,12]. Yet it is still unclear whether, or to what extent, such activation of the immune system is responsible for allogeneic heart valve failure.…”

Section: Introductionmentioning

confidence: 99%

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A Size-Matching Heterotopic Aortic Valve Implantation Model in the Rat

Oei¹,

Welters²,

Bonthuis³

et al. 1999

Journal of Surgical Research

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Early valvular obliteration of cryopreserved aortic valve allograft

Saito

Ohtsuka

Motomura

et al. 2003

Jpn J Thorac Caridovasc Surg

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This report describes a 60-year-old male patient who developed early valvular obliteration of a cryopreserved aortic valve allograft with associated severe valvular leakage. The patient had previously undergone two operations for aortic valve insufficiency resulting from infective endocarditis, and prosthetic valve endocarditis: aortic valve replacement with a mechanical prosthesis was done 4 years ago, and two years later aortic root replacement with a cryopreserved allograft was performed. Perforation through the non-coronary cusp of the aortic allograft was found, and valve replacement was achieved using a mechanical prosthesis. The intraoperative findings, histological, immunological, and bacteriological studies of the resected cusps demonstrated negative for infection and rejection, therefore, the valvular perforation might have been caused by an injury or degeneration during management of the homologous graft. The patient showed neither aortic regurgitation on echocardiography nor recurrence of endocarditis 10 months after surgery.

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Aortic valve grafts in the rat: Evidence for rejection

Abstract: Cardiac allograft valves in the rat model undergo changes that are characteristic of cell-mediated rejection and lead to valve failure.

Cited by 29 publications

References 18 publications

Cryopreservation of Rat Aortic Valves Results in Increased Structural Failure

Cryopreservation of Rat Aortic Valves Results in Increased Structural Failure

A Size-Matching Heterotopic Aortic Valve Implantation Model in the Rat

Early valvular obliteration of cryopreserved aortic valve allograft

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