Untersuchungen zur Regeneration der Trachea nach partiellem oder totalem Ersatz durch synthetisches resorbierbares Material (Polyglactin 910)

Abstract

Though longer distances of the trachea and segments of the bronchi can be resected and the blunts be joined by end-to-end anastomosis, the replacement of parts of the wall of the tracheobronchial tree may become necessary. Alloplastic not absorbable material like silicone was not successful because of its disposition to infections and development of stenosis. Absorbable suture material proved to be suitable in tracheal surgery and it was shown that texture of Polyglactin 910 (Vicryl) could even be used for replacement of the aortic wall. We used weaved tubes of 2.5 mm diameter as prostheses of this material. We partly resected the trachea in the throat of 30 rats and in a microsurgical procedure we replaced in 17 animals the whole circumference by the tube shaped prosthesis and in 13 animals a window in the trachea by a patch, cut from such a prosthesis. By pneumonia or granulation in the anastomosis region 11 rats died or had to be sacrificed untimely. The others survived in several periods up to 10 weeks. At the time of autopsy starting after 3 weeks, a newly formed trachea could be demonstrated, which is covered more and more with respiratory epithelium. By light microscopic and scanning microscopic examinations, the development of a new wall, similar to the normal one, was seen. This wall lacks only mucus glands, but contains structures similar to hyaline cartilage. Our absorbable prosthesis cannot prevent the development of stenosis by overshooting granulation in the early postoperative period, but very soon the material is absorbed and replaced by a structure similar to the normal wall. After biodegradation, problems appear by instability of the new tissue, because of collapsing during inspiration. This problem could be solved by covering the prosthesis by an additional supporting scaffold.

Epithelisierungsmodell nicht-biologischer Gewebeersatzmaterialien in vitro

“…Fibroblasten entwickelten brückenarti-ge Zellfortsätze in den Zwickeln des Greve und Holste [5] untersuchten den partiellen und totalen Wandersatz der Trachea im Tiermodell der Ratte durch Polyglactin 910 und beobachteten eine schrittweise Auskleidung des Lumens mit einem respiratorischen Epithel, was sehr gut mit den In vitroErgebnissen der vorliegenden Arbeit übereinstimmt. Langfristig besaß diese Neotrachea jedoch durch die Resorbierbarkeit des Implantats keine Wandstabilität, so daß sich konsekutiv ein inspiratorischer Kollaps ausbildete.…”