去部分黏膜游离空肠重建气管缺损肠黏膜组织学变化研究

Histological research of tracheal reconstruction by free jejunal graft with the mucosa partially preserved

目的通过建立去部分黏膜游离空肠重建气管缺损动物模型,研究去部分黏膜游离空肠修复缺损后的组织学变化,为应用于临床提供实验依据。方法选用通用标准实验动物Beagle犬6条,截取一段4 cm长的空肠段,从气管3～10环切除管周1/3,形成约1.2 cm×4.0 cm气管壁缺损,将游离空肠的肠系膜动脉和右侧颈总动脉行端侧显微血管吻合,肠系膜静脉与右侧颈内静脉行端端吻合,将移植空肠与气管壁吻合。实验组去掉部分空肠黏膜,对照组不去除空肠黏膜。术后分别于第1、2、3、6个月四个时间点,于吻合口和移植空肠肠腔中部取活检,标本行光镜和电镜检查。结果所有实验犬术中无死亡,创口I期愈合。移植游离空肠全部成活。实验组有1条Bea-gle犬在术后第2周因痰痂阻塞窒息而死,对照组有1条Beagle犬在术后第50天因造瘘口感染而死亡,其余Bea-gle犬均存活6个月以上。实验组术后2个月,移植空肠表面有鳞状上皮化生,未发现空肠腺体样结构;术后3个月时,移植空肠肠腔表面有假复层纤毛柱状上皮覆盖,黏膜层有淋巴细胞浸润,固有层有纤维组织。对照组术后3个月时,移植空肠肠腔表面出现非角化鳞状上皮覆盖;术后6个月,移植空肠表面均被假复层纤毛柱状上皮覆盖。结论去部分黏膜游离空肠重建气管,能加速肠黏膜腺上皮萎缩,促进假复层纤毛柱状上皮覆盖,为应用于临床提供了实验依据。

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 4 cm 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 1.2 cm×4.0 cm,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.