The evaluation of various bioabsorbable materials on the titanium fiber metal tracheal prosthesis

A new type of tracheal prosthesis was studied. It consists of a rigid, porous cylinder of titanium fiber metal coated with a polymer that provides an initial air seal and then is absorbed to permit subsequent fibrous tissue ingrowth and reepithelialization. Fifteen such cylinders measuring 50 mm by 26 mm were coated with one of the following polymers: polycaprolactone 700 (3 coated internally and 3 externally); a copolymer of 75% poly-L-lactic acid and 25% polyglycolic acid (3 coated internally and 3 externally); and polyglactin 910 (3 coated externally). Fifteen kennel-conditioned mongrel dogs, each randomly assigned to one of these five groups, underwent implantation of the prosthesis through a right thoracotomy into a 5-cm defect in the distal intrathoracic trachea. There were no immediate postoperative deaths, and no instances of major air leak from the prosthesis. One animal died after two weeks secondary to a lower respiratory tract infection. Bronchoscopic evaluation revealed varying degrees of tissue ingrowth into the prostheses, with no evidence of infection or distal accumulation of secretions. Histological evaluation showed superior tissue ingrowth and reepithelialization with internally coated prostheses; two out of three polymers gave good results.