[Experimental study on the reconstruction of circumferential tracheal defects with novel prosthesis]

To investigate the feasibility of using new tracheal prosthesis made of biomaterials to replace extensive circumferential tracheal defects in mongrel dogs.

Three types of tracheal prostheses were developed, whose basic skeleton of tubular mesh was knitted with polypropylene monofilament and poly (lactic-co-glycolic acid) fiber. The inner side of type-I tubular mesh was first coated with polyurethane solution and then with collagen. The exterior of type-I was then immobilized with collagen-hydroxyapatite composites. In contrast, the internal and external walls of type-II were coated with polyurethane solution, which produced a prosthesis similar to a nonporous one, while type-III was coated only with collagen solution. Surgical resection and replacement of a segment of the cervical trachea was performed in 16 adult mongrel dogs. The efficacy of the implanted prosthesis periodically evaluated postoperatively.

In group A, only one died from prosthetic dehiscence, another from anastomotic leakage, and the others had uneventful postoperative courses. The implanted prosthesis was completely incorporated with the recipient trachea, where different length of reepithelialization occurred on the luminal surface of the reconstructed trachea. Macroscopic examination showed scattered and different sizes of neo-ossification surrounding the implanted prosthesis. The prosthesis was roentgenopaque when exposed to routine X rays. In contrast, a relatively high number of complications occurred postoperatively in group B and C.

Type-I tracheal prosthesis may be used effectively for long-segment circumferential tracheal replacement, and appears very promising for clinical application, with further improvements in promoting the epithelialization.