目的:通过建立部分去除黏膜层的带蒂游离空肠段重建6.5cm袖状气管缺损动物模型,研究部分去黏膜空肠重建气管后空肠黏膜层的组织学变化。方法:比革犬8只,在制作好带蒂部分去黏膜游离空肠段后,肠腔内放置硅胶管内支架,空肠外面放置形状记忆镍钛合金外支架,切除犬的6.5cm长袖状气管后,将肠系膜动静脉分别与右侧颈总动脉、颈内静脉相吻合,重建气管缺损。术后分别于1、2、3、4个月各处死2只犬,于吻合口和移植空肠肠腔中部取活检,标本行光镜及电镜观察。结果:8只犬术后全部生存到预期时间,移植游离空肠全部成活。组织学观察术后1个月时空肠段重建气管的上皮层大量缩短的小肠绒毛,绒毛间有大量的纤维素性渗出和炎性细胞。术后2个月时小肠的绒毛明显稀疏减少、长度明显缩短,腺体萎缩,腺腔缩小,肠黏膜上皮层明显变薄。术后3个月时移植空肠腔上皮基本化生为鳞状上皮,4个月时移植空肠内腔部分鳞状上皮化生为假复层纤毛柱状上皮。结论:部分去黏膜游离空肠重建长段气管后可以加速肠腔黏膜层的萎缩及化生过程,3个月可见肠腔黏膜层化生为鳞状上皮、4个月时有部分鳞状上皮化生为假复层纤毛柱状上皮。
Objective: To explore the histopathological changes of the new trachea reconstruction with a scraped partial mucosa jejunal autograft by 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 1st, 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 anastomosis 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