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.
Martinod
Emmanuel
E
Laboratoire d'Etude des Greffes et Prothèses Cardiaques, Hôpital Broussais, Upres 264, Université Paris 6, France. emartinod@wanadoo.fr
Seguin
Agathe
A
Pfeuty
Karel
K
Fornes
Paul
P
Kambouchner
Marianne
M
Azorin
Jacques F
JF
Carpentier
Alain F
AF
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