Biological fate of tissue-engineered porcine valvular conduits xenotransplanted in the sheep thoracic aorta

  • Authors:
    • Maria Teresa Conconi
    • Francesco Rocco
    • Raffaella Spinazzi
    • Mara Tommasini
    • Carlo Valfrè
    • Roberto Busetto
    • Elvio Polesel
    • Giovanna Albertin
    • Angelo Dei Tos
    • Ilaria Iacopetti
    • Attilio Cecchetto
    • Claudio Zussa
    • Mauro Grigioni
    • Pier Paolo Parnigotto
    • Gastone Giovanni Nussdorfer
  • View Affiliations

  • Published online on: December 1, 2004     https://doi.org/10.3892/ijmm.14.6.1043
  • Pages: 1043-1048
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Abstract

The ideal prosthesis to replace the diseased human aortic valve is not yet available. We have previously shown that porcine acellular aortic-valve conduits, obtained by detergent-enzymatic method, display hemodynamic performances similar to those of their native counterparts. Hence, it seemed worthwhile to ascertain whether these tissue-engineered prostheses can be successfully xenotransplanted. Porcine acellular conduits, which immunocytochemistry demonstrated to lack MHC class I and II antigens, were implanted in the thoracic aorta of 9 sheep. Two animals died just after surgery, and the other 7 sheep were sacrificed 1 or 5 months after transplantation. A rather favorable outcome of the implant was observed in 4 sheep. In these animals, aortic valves remained pliable and coaptive, and the luminal surface of the conduits was endothelized just after one month from surgery. An intense inflammatory response was present at 1 month, and, although attennuated, it persisted for 5 months, located mainly between the tunica intima and media and at the border of the implant. Vimentin-positive and smooth muscle actin-positive myofibroblasts proliferated within tunica media and adventitia, and an obvious thickening of the tunica intima was also observed. Small vessels were seen in the adventitia, and elastic fibers were well-preserved in both the aorta wall and valve leaflets. In the cases of unfavorable outcome (3 of 7 survived sheep), implants were detached from the aorta recipient and surrounded by a connective mass that almost completely obstructed their lumen. These masses were composed of a fibromyxoid background where proliferating cells, resembling those occurring in human reactive myofibroblastic lesions (proliferative fascitis), were embedded. Collectively, these rather disappointing findings indicate that acellular valve conduits, obtained by the detergent-enzymatic method, are presently not suitable for clinical applications because of the persistent inflammatory response, which conceivably triggers overgrowth mechanisms that lead to implant failure.

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December 2004
Volume 14 Issue 6

Print ISSN: 1107-3756
Online ISSN:1791-244X

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Spandidos Publications style
Conconi MT, Rocco F, Spinazzi R, Tommasini M, Valfrè C, Busetto R, Polesel E, Albertin G, Dei Tos A, Iacopetti I, Iacopetti I, et al: Biological fate of tissue-engineered porcine valvular conduits xenotransplanted in the sheep thoracic aorta. Int J Mol Med 14: 1043-1048, 2004
APA
Conconi, M.T., Rocco, F., Spinazzi, R., Tommasini, M., Valfrè, C., Busetto, R. ... Nussdorfer, G.G. (2004). Biological fate of tissue-engineered porcine valvular conduits xenotransplanted in the sheep thoracic aorta. International Journal of Molecular Medicine, 14, 1043-1048. https://doi.org/10.3892/ijmm.14.6.1043
MLA
Conconi, M. T., Rocco, F., Spinazzi, R., Tommasini, M., Valfrè, C., Busetto, R., Polesel, E., Albertin, G., Dei Tos, A., Iacopetti, I., Cecchetto, A., Zussa, C., Grigioni, M., Parnigotto, P. P., Nussdorfer, G. G."Biological fate of tissue-engineered porcine valvular conduits xenotransplanted in the sheep thoracic aorta". International Journal of Molecular Medicine 14.6 (2004): 1043-1048.
Chicago
Conconi, M. T., Rocco, F., Spinazzi, R., Tommasini, M., Valfrè, C., Busetto, R., Polesel, E., Albertin, G., Dei Tos, A., Iacopetti, I., Cecchetto, A., Zussa, C., Grigioni, M., Parnigotto, P. P., Nussdorfer, G. G."Biological fate of tissue-engineered porcine valvular conduits xenotransplanted in the sheep thoracic aorta". International Journal of Molecular Medicine 14, no. 6 (2004): 1043-1048. https://doi.org/10.3892/ijmm.14.6.1043