镍钛合金组合式人工食管替代食管术后新生食管的形成与重构

Experimental study of construction of the neoesophagus following a nitinol alloy composite artificial esophagus replacement of esophagus

目的观察镍钛合金组合式人工食管替代食管术后,新生食管的形成及重构。方法22只猪通过手术切除一段长约7 cm的胸段食管,应用镍钛合金组合式人工食管替代切除的胸段食管建立实验动物模型。对置入人工食管术后1、2、3、6个月各时段出现植入人工食管脱落移位的12只实验动物,进行X线食管造影,然后剖杀,对比观察各时段形成的新生食管的大体形态,镜下管体组织细胞结构的变化。结果12只实验动物中6只早期脱管（术后1个月内）,3只并发吻合口瘘和脓胸,另3只则出现严重吻合口狭窄;余6只脱管时间超过1个月,未发生吻合口瘘和胸腔感染,仅出现不同程度的新生食管狭窄和进食困难。镍钛合金组合式人工食管替代食管术后1个月,人工食管外壁形成一条以结缔组织膜包绕,连接正常食管两端的管道。2～3个月的新生食管管体结构,除中间狭窄部分为结缔组织外,已形成与正常食管4层组织结构相似的纤维肌性管道。3～6个月新生食管管体组织结构呈现肉芽组织增生、瘢痕组织形成的重构过程。全程未发现腺体组织。结论镍钛合金组合式人工食管作为修复材料重建食管通道置入人体后,诱导出由结缔组织包绕人工食管外壁的管道,新生食管在随后的重构过程中发生肉芽组织增生,瘢痕组织形成的转化过程,最终形成一条没有收缩功能、黏膜面覆盖复层鳞状上皮的瘢痕性管道。

Objective To observe the construction of the neoesophagus following a Nitinol alloy composite artrificial esophagus replacement of esophagus. Methods Nitinol alloy composite artificial esophagus was made up of Nitinol tube coated with a silicone membrane with a dacron flange 1 cm proximal to each end. A segment of 7 cm long thoracic esophagus was excised and replaced with this graft. Replacement was done in 22 pigs. After the operation, in 12 pigs the grafted prostheses sloughed out spontaneously in 1, 2,3,6 months were examined by esophagography and were killed for autopsy. The neoesophagus modality, histiocyte construction was observed. Results Six of 12 pigs the grafted prostheses sloughed out spontaneously within 30 days after the operation. Three pigs had anastomotic leakage and pyothorax. The other had serious stenosis at the site of anastomosis. Six of 12 pigs the grafted prostheses sloughed out spontaneously after a month postoperafion. All had various degrees of the neeesophagus stenosis and difficulty in eating. One month after the operation the artificial esophagus was surrounded by a tube made of connective tissue. 2 - 3 months later, the neeesophagus showed a thin stratified squamous epithelium over a thick layer of Fthrous connective tissue and smooth muscle layers at both ends similar to the normal esophageal constitution. Between 3 - 6 months, the neeesophagus histology become a scar tube. Conclusion In the course of the formation and re-construction of the neeesophagus, the granulation tissue is gradually replaced by scar tissue. At last, the neoesophagus become aperistaltic.