[Carbon-carbon materials and composites for experimental tracheal reconstruction]

The Carbon fiber reinforced carbon matrix composites were employed for reconstruction of large circumferential defect of the cervical trachea. The biocompatibility and biofunctionality of the new type carbonaceous tracheal prosthesis were evaluated, and the feasibility for cervical tracheal reconstruction discussed.

Two types of carbonaceous tracheal prosthesis with different weaving methods of carbon fiber were used on eight healthy canines. Three to six tracheal cartilage rings were resected circumferentially. The 2 cm long tracheal prosthesis was transplanted into canines and the anastomosis was completed by end-to-end, tracheal-into-prosthesis and prosthesis-into-tracheal method. The function of breathing, eating and infection was observed after surgery. Four months later, the five survival canines were sacrificed and the prosthesis with surrounding tissues was removed for observation by optical microscopy and scanning electron microscopy.

All dogs had cough symptom in different degree lasted 1 - 4 weeks after surgery. Two dogs with tracheal-into-prosthesis anastomosis showed eating disorders in different degree. One canine died due to airway obstruction caused by dislocation of prosthesis within three weeks after operation. Another two deaths in 11th week and 12th week were attributed to suffocation because of hypergranulation and scar formation. Prosthesis was surrounded by connective tissues and anchored firmly to the neighboring tissues. Most part of the luminal surface of tracheal prosthesis was not covered by respiratory mucosa. However, the inner layer showed scant re-epithelialization beyond the anastomosis.

The implantation of the carbonaceous tracheal prosthesis can maintain the normal respiratory function of the experimental canines, but hypergranulation and scar formation around the end of the tracheal prosthesis and epithelium on the luminal surface of the prosthesis are questions still remained to be solved.