Experimental study of a porous rat tracheal prosthesis made of T40: long-term survival analysis

In order to repair large defects in the laryngotracheal area, we developed a biomaterial based on porous titanium (Ti40) formed of spherical particles that are welded together. These Ti40 beads were arranged in several layers to create the rat tracheal prosthesis. After a partial tracheal resection, the prosthesis was fixed to both extremities to replace the missing part. Tissue surrounding the prosthesis was collected from 33 surviving animals after an implantation period of 3 to 12 months. Histological analyses showed that the periphery of the prosthesis was covered with fibroblasts and a few lymphocytes that penetrated the titanium layers. A ciliary cylindrical epithelium of respiratory type was found on the endoluminal side. The inflammatory reaction observed was minimal. These data indicate that the prosthesis, implanted in a laryngotracheal environment, is well tolerated by animals. Our results represent the first step towards the construction of a total laryngeal prosthesis that should allow restoration of the essential functions of the larynx after a laryngectomy in cancer treatment.