Abstract:

Objective    To explore the histopathological changes by microscope and transmission electron microscope. Methods    Six Beagle dogs were randomly divided into two groups: the experimental group and the control group. Operations were performed on these dogs under general anesthesia by intravenous ketamine. A 4cm length of segment of the jejunum was resected. The experimental group was prepared by scraping the partial muscosa with an operating knife blade and dry gauze, while in the control group the muscosa of jejunum was not scraped. One third of circumferential tracheal wall was resected from the third to tenth tracheal rings, and nick area about 1.2cm×4.0cm, 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. Then, the free jejunum was uesed to reconstruct the tracheal defects， Fibrescope and biopsy were performed and recorded at the 1st, 2nd, 3rd and 6th postoperative months. All specimens were observed by microscope and transmission electron microscope examinations. Results    No dogs died in the operation, and the wound healed  well at  period I, but one dog died from obstruction of secretion in the tracheal tract at the 2nd postoperative week in the experimental group, another dog died from tracheostomy infection at the 50th postoperative days in the control group, and the others survived more than 6 months. After two month,  squamous epithelium  was found in the scraped jejunal mucosa. After three month, interestingly, ciliated columnar epithelium was found in the scraped jejunal mucosa. But in control group,  squamous epithelium was found in the scraped jejunal mucosa of the autografts at three months post-operation. After six months the new tracheal lumen was covered by ciliated columnar epithelium in all experimental Beagle dogs. Conclusions    A free scraped partial jejunum accelerated the process of mucous epithelization and promoted the metaplasia of the ciliated columnar epithelium.

Key words: Tracheal reconstruction；Jejunum；Autologous； microvascular anastomosis