Tracheal replacement by allogenic aorta in the pig.
BACKGROUND
To assess whether fresh aortic allografts (AAs) can be used for tracheal replacement.


METHODS
Twenty-one male minipigs underwent tracheal replacement using AAs harvested from female pigs. The length of replaced segments exceeded 50% of the trachea. A stent was implanted into the lumen of the AA to prevent collapse. The animals were killed at 3-month intervals, and AAs were assessed for ingrowth of respiratory epithelium and cartilage formation and tested for type II collagen formation and the presence of the SRY gene.


RESULTS
A high stent migration rate was observed. Only 10 pigs and 4 pigs made it to follow-up periods exceeding 3 months and 9 months, respectively. Neither rejection nor ischemia were observed. At 3 months, a metaplastic epithelium lined the graft. At 10 months, a posterior membrane could be seen with immature cartilage and disorganized elastic fibers. SRY gene assay showed that the cells engrafted in the AAs, particularly at the level of the newly formed cartilage, were of male origin and thus originated from the recipient.


CONCLUSIONS
This study confirms that a fresh AA, replacing more than half of the trachea of the pig, transforms into a conduit containing the major tracheal components. These components are relatively immature and do not as of yet replicate the form and function of the native trachea. Questions remain concerning the exact mechanisms of this process. Further research on the role of tracheal replacement is recommended.
Jaillard
Sophie
S
Département de Chirurgie, Polyclinique du Bois, Lille, France.
Holder-Espinasse
Muriel
M
Hubert
Thomas
T
Copin
Marie-Christine
MC
Duterque-Coquillaud
Martine
M
Wurtz
Alain
A
Marquette
Charles-Hugo
CH
D000818:Animals; D001011:Aorta / Q000473:pathology / Q000637:transplantation*; D002356:Cartilage / Q000166:cytology; D003094:Collagen / Q000378:metabolism; D004247:DNA / Q000235:genetics / Q000378:metabolism; D005260:Female; D005548:Foreign-Body Migration; D024282:Genes, sry / Q000235:genetics; D008297:Male; D020545:Respiratory Mucosa / Q000378:metabolism / Q000473:pathology; D015607:Stents; D013552:Swine; D013556:Swine, Miniature; D014132:Trachea / Q000601:surgery*; D014184:Transplantation, Homologous; D019737:Transplants
D003094:Collagen; D004247:DNA