The Fate of Homograft Tracheal Transplants in Sheep

Abstract

The results from this animal experiment reveal-contrary to data published to date-that tracheal homografts are not incorporated but absorbed. They are replaced by scar/granulation tissue that cannot secure the stability of the trachea. Therefore, further experiments with respect to the biocompatability of homografts appear to be necessary.

Successful Circumferential Free Tracheal Transplantation in a Large Animal Model

“…Behrend et al have reported consistent failure of autografts [15] and allografts [16] in sheep, postulating that tracheal homografts in this animal model undergo necrosis and reabsorption, and are unavoidably destined to be replaced by a fibrous scar. On the other hand, Murakawa et al [17] obtained satisfactory results with noncircumferential transplantation of five rings in primates, but only leaving intact the membranous portion of the host and in a small number of animals.…”

“…Many previous studies have mentioned infection as a probable cause of graft failure in the sheep, [3,15,16] and it is possible that this complication is mainly…”

3D Bioprinted Artificial Trachea with Epithelial Cells and Chondrogenic-Differentiated Bone Marrow-Derived Mesenchymal Stem Cells

“…Various materials, that is, from synthetic products to biological tissues, were used for tracheal tissue reconstruction; however, previous reports with sufficiently successful outcomes are limited. Behrend et al reported in a study of homogenic tracheal transplantation in sheep that the grafts were completely absorbed and replaced by inflammatory scar tissue; thus, the stability of the trachea could not be secured [ 18 ]. A study of tissue-engineered allograft, using fibrin-hyaluronan composite gel and chondrocyte, by Kim et al showed partial success, with fine luminal contour of the regenerated site but insufficient neo-cartilage formation [ 19 ].…”