生物材料人工气管的设计与动物实验研究

Designing of a novel tracheal prosthesis made from composite biomaterials

目的 :通过筛选适宜的生物材料和选用特殊的成型工艺自行研制新型人工气管假体 ,探讨其用于长段气管缺损重建的可行性。方法 :根据理想化气管替代物的要求 ,设计出 型人工气管 :由聚丙烯单丝、聚乙丙交酯纤维编织成直管状网管 ,内壁涂以聚氨酯薄膜和胶原蛋白 ,涂层材料不能透过外壁网孔 ,外壁采用胶原蛋白 -羟基磷灰石多孔状海绵覆盖。作为对照的 型人工气管 ,网管结构与 型相同 ,内外壁均涂以聚氨酯。分别将 型、 型人工气管用于实验组 (8只 )和对照组 (4只 )动物 ,构建犬颈部气管置换与重建的动物模型。结果 :实验组犬术后人工气管假体能迅速被宿主气管周围组织包绕而达到生物学固定 ,假体在位良好 ,吻合口肉芽生长不明显 ;假体内腔可见不规则黏膜上皮生长 ,色较苍白 ,未铺覆内腔全长 ;包绕假体的周围组织中可扪及散在的大小不等的硬质骨性结构 ;动物存活时间长。而对照组术后均出现不同程度的假体松脱现象 ,并发生局部漏气、感染及狭窄等并发症。结论 :该生物材料人工气管可用于长段气管置换重建手术 ,具有一定的开发利用价值和临床应用前景。

Objective: To design a novel tracheal prosthesis made from composite biomaterials, and to study its feasibility for replacing cervical trachea in mongrel dogs. Methods: Twelve adult mongrel dogs(weighing 16.3 21.8 kg) were used to establish the experimental models.We designed 2 types of tracheal prosthesis.Type Ⅰ prosthesis was a tubular knitted mesh made of polypropylene monofilament and polyglactin fiber,the luminal surface was coated with polyurethane and collagen,and the exterior surface was covered with collagen and hydroxylapatite sponge.The mesh structure of type Ⅱ was similar to the type Ⅰ,but the coating materials on the internal and external surface of the mesh were all polyurethane. Results: In experimental group( n =8),the tracheal prosthesis were completely incorporated with the native trachea and adherent to the surrounding tissues postoperatively.No dehiscence and dislocation of prosthesis occurred in this series.The granuloma formation at the sites of the anastomoses in this group was less serious than that of the control group.Various degrees of epithelial lining were observed on the luminal surface,but confluent epithelization was seen in none of the 8 dogs.In addition,many scattered neo ossification substances of various sizes were found at the sites of the local surrounding tissues.In control group( n =4), various degrees of dehiscence and displacement of prosthesis often occurred after operation, resulting in severe and fatal postoperative complications such as local infection,anastomotic leakage,marked granuloma formation and so on. Conclusions:This tracheal prosthesis made of composite biomaterials has high biocompatibility and the potential for the long segment circumferential tracheal reconstruction and for the clinical repair of tracheal defects.