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[Histopathologic changes after tracheal reconstruction with a scraped partial mucosa jejunal autograft].

OBJECTIVE
To explore the histopathological changes of the new trachea reconstruction with a scraped partial mucosa jejunal autograft hy microscope and transmission electron microscope.


METHOD
Eight canine models of extensive circumferential tracheal defects with revascularized jejuna combined with NiTi alloy mesh tube were established. Operations were performed on these dogs under general anesthesia by intravenous ketamine. A 6.5 cm length of segment of the jejunum was resected. The graft was prepared by scraping the partial mucosa with operating knife blade and dry gauze. During the resecting course, micro-vascular anastomoses were done between the mesenteric artery and the right common carotid artery,and the mesenteric vein with the right common carotid vein. The silicone intraluminal stent was placed in the lumen of the jejunal segment and was removed the fourth week after operation. A Ni-Ti alloy prothesis was placed over the jejunal segment, with the mesenteric vascular supply egressing through the longitudinal defect of the mesh tube. Then the free jejunum was used to reconstruct the tracheal defects. Biopsy were performed and recorded at the 1 at, 2nd, 3rd and 4th postoperative months. All specimens were observed by microscope and transmission electron microscope examinations.


RESULT
Eight dogs postoperative all survived expected time. One month after operation, the tracheointestinal snastomosis showed smooth and was covered by continuous internal lining. The mucosa of the jejunum was slightly atrophied. Two months after operation, examination of the jejunal mucosa of the autografts demonstrated obviously thinned. The lumen of the reconstructed trachea was covered by squamous epithelium entirely at 3 months postoperatively. The partial squamous epithelium has transformed ciliated columnar epithelium at 4 months postoperatively.


CONCLUSION
A free scraped partial jejunum reconstructed trachea can accelerated the atrophying process of mucous epithelization and promoted mucosal metaplasia of the jejunum. The reconstructed tracheal lumen has completely transformed squamous epithelium at 3 months postoperatively and partial squamous epithelium has transformed ciliated columnar epithelium at 4 months postoperatively.