Revascularization of canine cryopreserved tracheal allografts.
BACKGROUND
We examined the blood supply of a cryopreserved tracheal allograft and its morphohistologic changes after transplantation.


METHODS
In each of 22 dogs, a five-ring tracheal segment was replaced by one of the following tracheal grafts: fresh autografts (n = 8), cryopreserved tracheal allografts (n = 8), or fresh allografts (n = 6). The cryopreserved tracheal allografts were preserved at -196 degrees C for 60 days. No immunosuppressant was given to any of the animals. All grafts were retrieved at 1 and 12 weeks and assessed by microangiography and histology.


RESULTS
The epithelial denudation and the revascularization of the transverse intercartilaginous arteries were recognized within 7 days as common to each of the three types of grafts. In the cryopreserved tracheal allografts, neither cartilage degradation nor graft shrinkage occurred at 7 days. However, the recanalized transverse intercartilaginous arteries completely disappeared at 12 weeks, and marked shrinkage occurred; the cartilage cells were accompanied by karyolysis and were significantly decreased in number (p < 0.05). Recanalization of the transverse intercartilaginous arteries was also demonstrated in the fresh allografts; however, necrosis abruptly occurred as a result of acute rejection responses.


CONCLUSIONS
Cryopreservation of a tracheal allograft provided sufficient reduction of the acute rejection responses, and blood supply to the cryopreserved tracheal allograft was established through the recanalized transverse intercartilaginous arteries within 7 days; however, subsequent chronic rejection responses resulted in occlusion of the transverse intercartilaginous arteries and atrophy.
Moriyama
H
H
First Department of Surgery, Asahikawa Medical College, Japan.
Sasajima
T
T
Hirata
S
S
Yamazaki
K
K
Yatsuyanagi
E
E
Kubo
Y
Y
D000818:Animals; D001158:Arteries / Q000473:pathology; D001284:Atrophy; D015925:Cryopreservation; D004285:Dogs; D005260:Female; D008297:Male; D008866:Microsurgery; D009926:Organ Preservation; D015427:Reperfusion Injury / Q000473:pathology*; D014132:Trachea / Q000098:blood supply / Q000473:pathology / Q000637:transplantation*; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous