Study on Tracheal Prosthesis using promotive materials for tissue regeneration

(1)我们用我们的人工气管替换了狗的胸内气管。气管假体由Marlex补片（聚丙烯补片）组成，补片由连续聚丙烯螺旋增强，并移植和涂覆猪真皮胶原。在手术中，气管假体和吻合部位的空气泄漏是最小的。所有假体均与宿主组织完全融合。然而，观察到补片暴露于气管腔的情况比先前在颈部气管处进行的置换实验中更为明显。(2)为了克服这个问题，我们在胸内气管置换术中增加了网膜固定术。结果，新粘膜的再生比以前没有网膜固定的替换更快，更完全。组织学观察显示，再生上皮更快、更完全。但由于部分犬仍有气管狭窄残留，需要进一步改善管腔狭窄，促进上皮再生。(3)因此，我们制造了一种新的人工气管，以促进新粘膜的再生。该假体由与实验（1）中使用的假体相同的材料作为主体，在其上层压由猪真皮胶原制成的胶原海绵。这种新的气管可以部分克服两个主要问题，如管腔狭窄和网状物暴露。然而，由于胶原海绵容易从补片圆柱体上脱落，因此认为吻合部位的并发症容易发生。由于该气管的漏气在某些胸腔内置换术中是致命的，因此使用胶原海绵似乎不如预期有效。

(1) We replaced the intrathoracic trachea of dogs'using our tracheal prosthesis. The tracheal prosthesis consists of Marlex mesh (polypropylene mesh) reinforced with a continuous polypropylene spiral, which is grafted and coated with porcine dermal collagen. At the operation the air leakage from the tracheal prosthesis and anastomotic site were minimal. All the prosthesis were completely incorporated with the host tissue. However, the exposure of mesh to tracheal lumen were more remarkably observed than in the previous experiment of replacement at the cervical trachea.(2) In order to overcome this problem, we added omentpexy to the intrathoracic tracheal replacement prosedure. As the result, the regeneration of neomucosa was faster and more complete than in the previous replacements without omentopexy. Moreover, in histological study, the epithelial regeneration were faster and more complete. But, since there were still remain in some dogs, stenoses of tracheal lumen furter improvement is requiered to promote the epithelial regeneration.(3) Therefore, we manufactured a new tracheal prosthesis to promote the regeneration of neomucosa. This prosthesis consists of tthe same as the prosthesis used in the experiment (1) as a bulk on which collagen sponge made from porcine dermal collagen was laminated.We replaced dog's cervical tracheae using this prosthesis. This new trachea could partially overcome the 2 major problems such as stenosis of the lumen and exposure of the mesh. However, since collagen sponge easily came off from the cylinder of mesh, the complications at the anastomotic sites is consider to be ready to occure. As the air leakage from this trachea were lethal in some intrathoracic replacements, the use of collagen sponge appeared not so effective than expected.