自体心包包裹人工气管修复气管缺损的组织相容性评估

背景：记忆合金支架材料具有可靠、稳定、相容性好的特点，长段气管缺损（大于6个气管环）的气道修复往往需要借助人工材料完成，记忆合金材料的生物学特点是否适应人工气管复合体基本支架的应用？ 目的：评估自体心包包裹记忆合金带孔支架人工气管修复犬气管缺损的组织相容性。 设计、时间及地点：于2005-09/2007-03在上海交通大学医学院附属仁济医院心胸外科实验室完成随机分组的动物对照实验。 材料：健康成年杂种犬22只。人工气管假体3种：镍钛记忆合金假体、镍钛记忆合金外涂胶原假体、镍钛记忆合金外包自体心包形成的生物人工复合假体。 方法：22只犬按随机数字表法分为3组。基本假体组（镍钛记忆合金材料）7只，胶原涂层组（镍钛记忆合金材料表面覆胶原涂层）8只，复合假体组（镍钛记忆合金材料表面覆自体心包）7只。人工气管植入修复犬气管缺损。基本假体组与胶原涂层组犬行人工气管与自体气管端端吻合，复合假体组吻合后外包自体心包片。 主要观察指标：比较3种人工气管植入后的稳定性及长期存活的可能性。 结果：早期死亡实验犬4只：2只死于吻合口瘘，1只死于吻合口狭窄，1只死于出血；9只麻醉后人工处死；9只存活>3个月。X射线片显示各组犬人工气管在位良好。大体观察：犬颈部肌肉将人工气管紧密包裹并固定在气管床内，管腔内壁有一层纤维结缔组织覆盖。肉眼可见吻合口向人工气管内壁有少量上皮细胞生长（5 mm），光镜检测提示为假复层纤毛柱状上皮，偶见有鳞状上皮化生。这种生物学特性在胶原涂层组和复合假体组中优于基本假体组。术后并发症：基本假体组吻合口瘘2只，吻合口狭窄2只；胶原涂层组吻合口瘘1只，吻合口狭窄2只，出血1只；复合假体组吻合口狭窄2只，感染1只。 结论：带孔记忆合金支架加自体心包材料组成的复合型人工气管外层组织相容性好，周围自身组织攀附并紧密包裹假体，能限制人工气管移位。

Histocompatibility of autologous pericardium-covered tracheal prosthesis to repair tracheal defect

BACKGROUND: Memory metallic material is reliable, stable and good compatible with the tissues. Repairing of long tracheal defects (more than six tracheal rings) often requires artificial materials. Are the biological characteristics of memory alloy materials are suitable for the basic tubular skeleton of tracheal prosthesis? OBJECTIVE: To assess the histocompatibility of autologous pericardium-covered porous memory metallic tracheal stents to repair canine tracheal defect. DESIGN, TIME AND SETTING: It was a randomized controlled animal study performed from November 2005 to March 2007 at the Cardiothoracic Laboratory in Renji Hospital, Medical College of Shanghai Jiao Tong University. MATERIALS: Twenty-two adult mongrel dogs were randomly divided into three groups: basic prosthesis group (n=7, Ni-Ti memory alloy wired prosthesis), collagen sponge group (n=8, Ni-Ti memory alloy prosthesis coated with collagen), and complex prosthesis group (n=7, Ni-Ti memory alloy prosthesis wrapped with pericardium). Tracheal prosthesis is end-to-end anastomosis with the native tracheal in basic prosthesis group and collagen sponge group, while tracheal prosthesis was wrapped with native pericardium after anastomosis in the complex group. MAIN OUTCOME MEASURES: The stability of three tracheal prosthesis and their possibility for long-term survival after implantation were compared. RESULTS: Four dogs died in the early time of this study: two died of anastomotic leakage, one died of anastomotic stenosis, and one died of hemorrhage. Nine dogs were killed after anesthesia. Nine survived more than three months. It was displayed in X-ray film that all tracheal prosthesis situated in proper situation. General observation: The tracheal prosthesis was wrapped with canine neck muscles in the tracheal bed. The lumen wall of the tracheal prosthesis was covered with a layer of fibrous connective tissue. Some epithelial cells migrated to the lumen wall of the tracheal prosthesis (5 mm) were also observed. They were the sham-columnar epithelium cilia in microscope. Occasionally there were squamous metaplasia. The biological characteristics in collagen sponge group and complex group were better than those in basic prosthesis group. Postoperative complications: There were two cases with anastomotic leakage and two cases with anastomotic stenosis occurred in the basic prosthesis group. One case with anastomotic leakage, two cases with anastomotic stenosis and one case with hemorrhage were found in the collagen sponge group. There were two cases with anastomotic stenosis and one case with anastomotic infection in the complex group. CONCLUSION: The complex porous memory alloy tracheal prosthesis wrapped with autologous pericardium has good biocompatibility. It is incorporated with the recipient tissues, which restricts the shift of tracheal prosthesis.