Experimental study on a new tracheal prosthesis made from collagen-conjugated mesh

A new tracheal prosthesis was made from fine Marlex mesh reinforced with a continuous polypropylene spiral. The mesh and spiral were covalently grafted and further coated with pig collagen with the aim of promoting connective tissue infiltration and providing initial airtightness. Complete surgical resection and replacement of a segment (2 cm in length, three to five tracheal rings) of the cervical trachea was performed in 13 adult mongrel dogs. Two dogs died of pneumonia about 2 months after operation, and eleven dogs were killed between 3 and 26 months. The prostheses in all dogs were promptly infiltrated by the surrounding connective tissue and completely incorporated by the host trachea. Formation of respiratory epithelium, which lined the prosthetic lumen, was seen to various degrees, and, in five dogs killed at 6 months or more after reconstruction, confluent epithelialization was confirmed histologically from the upper to the lower anastomotic site of the prosthesis. Marked stenosis of the prosthetic lumen caused by excessive scar tissue growth was seen in three dogs, and ulceration on the luminal surface was seen in two dogs. These results indicate that this tracheal prosthesis is highly biocompatible and promising for the repair of tracheal defects after further investigation.