Long-term evaluation of the replacement of the trachea with an autologous aortic graft.
BACKGROUND
Tracheal reconstruction after extensive resection remains a challenge in thoracic surgery. The goal of this experimental study was to analyze the long-term evolution of tracheal replacement using an autologous aortic graft.


METHODS
In 21 sheep, a 5-cm segment of the cervical trachea was replaced by a segment of the descending thoracic aorta that was reconstructed to a prosthetic graft. Because of the airway collapse reported in a previous series, a permanent (n = 13) or temporary (n = 8) stent was systematically placed in the lumen of the graft. Clinical, bronchoscopic, and histologic examinations were performed up to 3 years after implantation.


RESULTS
All animals survived the operation with no paraplegia. In the group with a permanent stent, three complications occurred: one stent displacement, one laryngeal edema, and one infection. Stent removal was tolerated after 6 months in the group with a temporary stent. Histologic examination showed a progressive transformation of the arterial segment into first extensive inflammatory tissue with a squamous epithelium, and after 6 to 36 months well-differentiated tracheal tissue including a continuous mucociliary epithelium and regular rings of newly formed cartilage.


CONCLUSIONS
An autologous aortic graft used as a substitute for extensive tracheal replacement in sheep remained functional for periods up to 3 years. The progressive transformation of the graft into a structure resembling tracheal tissue seems to be a key factor in long-term patency. The mechanism of this regenerative process and the possibility of using arterial homografts, which would make clinical application easier, remain to be evaluated.
Laboratoire d'Etude des Greffes et Prothèses Cardiaques, Hôpital Broussais, Upres 264, Université Paris 6, France. emartinod@wanadoo.fr
Emmanuel
E
Martinod
Agathe
A
Seguin
Karel
K
Pfeuty
Paul
P
Fornes
Marianne
M
Kambouchner
Jacques F
JF
Azorin
Alain F
AF
Carpentier
D000818:Animals; D001013:Aorta, Thoracic / Q000473:pathology / Q000637:transplantation*; D012756:Sheep; D015607:Stents / Q000009:adverse effects; D014132:Trachea / Q000473:pathology / Q000601:surgery*; D014182:Transplantation, Autologous