镍钛合金组合式人工食管替代食管的实验研究

Experimental study of replacement of an esophageal segment with an nitinol alloy composite artificial esophagus

目的观察镍钛合金组合式人工食管替代一段食管的可行性。方法镍钛合金组合式人工食管是由柔性硅胶膜覆盖镍钛合金网状支架作管体,距两端1 cm处管体上带有涤纶连接环的组合式人工食管。以10只猪作实验动物,分为Ⅰ、Ⅱ两组(每组5只),行手术切除一段长约7 cm的胸段食管,应用镍钛合金组合式人工食管替代建立实验动物模型,Ⅰ组用单纯镍钛合金组合式人工食管与正常食管做套入式端端全层吻合连接,Ⅱ组在Ⅰ组连接基础上,于镍钛合金组合式人工食管套入正常食管重叠处的食管外面加用涤纶条环绕固定。术后观察动物的进食及生长情况,3个月内每月做1次x线食管造影、电子纤维食管镜检查,处死3只术后66,100和123 d脱管的实验动物进行解剖,并对新生食管行病理学检查。结果两组共10只实验猪存活超过6个月以上,最长的存活已达20个月余。全组无吻合口漏发生,所有实验动物在人工食管未脱落之前都能正常进食。7只实验猪在术后2～6个月内发生脱管,Ⅰ组3只术后3个月内脱管,脱管后发生新生食管狭窄,进食出现严重梗阻；Ⅰ组1只和Ⅱ组3只术后3个月后脱管,脱管后短时间内发生轻度新生食管狭窄,随后逐渐缓解,无进食困难。Ⅰ组1只、Ⅱ组2只实验猪超过术后10个月未发生脱管,新生食管无狭窄,进食顺畅。结论镍钛合金组合式人工食管替代猪被切除食管段,近期效果较好。

Objective To observe the feasibility of a segment thoracic esophagus replaced by using a nitinol alloy composite artificial esophagus. Methods A nitinol alloy composite artificial esophagus was made of a nitinol tube coated with a silicone membrane with a dacron flange 1 cm proximal to each end. There were ten pigs for the models of experimental animal. The models of experimental animal were established by excised a segment of 7 cm long thoracic esophagus and replaced with the graft. In accordance with the different anastomosis connective way 10 pigs were divided into group Ⅰ and group Ⅱ , every group had 5 pigs. In group Ⅰ monolayer end-to-end anastomosis was used with this prosthesis. In group Ⅱ monolayer end-to-end anastomosis was used with this prosthesis and above the site of anastomosis adding dacron strip fixed. After operation the operate animals were observed for eating and health. Esophagography and flexible esophagoscopy were performed once a month at the first, second, and third postoperatively month. Three pigs of the grafted prostheses sloughed out spontaneously at different postoperatively period were killed for autopsy and pathologic examination of the neoesophagus. Results All pigs had no leakage at the site of anastomosis and survived over 6 months. The longest survival was 20 months. Seven of 10 pigs the grafted prostheses sloughed out spontaneously at 2 to 6 months after the operation （4 in group Ⅰand 3 in group Ⅱ ）. The grafted prostheses sloughed out spontaneously less than 3 months after operation, marked neoesophageal stenosis in the grafted portion was recognized （ 3 in group Ⅰ ）. They displayed serious difficulty in eating. But the prothesis sloughed out spontaneously more than 3 months after operation, neoesophageal stenosis was increased slightly and the stenosis was only temporary and gradually resolved. （ 1 in group Ⅰ ,3 in group Ⅱ ） They lived in good health and without difficulty in eating. Three of 10 pigs the grafted prosthesis still stayed in the grafted place over 10 months （ 1 in group Ⅰ , 2 in group Ⅱ ）. The neoesophageal had no stenosis . They were perfectly well in eating. Conclusions A segment excised pig esophagus replaced with a nitinol alloy composite artificial esophagus is feasible and takes a better result.