[An experimental study on surgical treatment of tracheomalacia-- methods for making models of tracheomalacia and development of a new operative method]

To develop a new surgical method for the repair of tracheobronchomalacia, we conducted experiments on dogs. First, we created malacic models by fracturing or resecting 5 to 10 tracheal cartilages. The bearing strength of the tracheal lumen became remarkably weakened, and bronchoscopic examination revealed tracheal collapses during coughing. Second, we tried external stenting of the malacic tracheae with prostheses. In 11 dogs, a prosthesis composed of Silastic sheet and Marlex mesh was sutured to the malacic segments of trachea. The connective tissue around the prosthesis increased in amount and the tracheal wall became firmer with time. However, mucosal defects around the sutures were found in 4 of the dogs. Those defects were probably due to injury to capillaries by the suturing procedures. Therefore, instead of suturing, we decided to try adhesives for fixation of the prosthesis to the trachea. We tested three adhesives: PUP (polyurethane-prepolymer), cyanoacrylate and fibrin glue. In five dogs using cyanoacrylate, the tracheal walls were remarkably hardened within 3 to 8 months. In eight dogs using fibrin glue for fixation of Marlex mesh to the malacic trachea the results were satisfactory. With fibrin glue, the tracheal walls after 3 to 8 months had almost the same strength as the average of normal tracheae.