[An experimental study on SIS in reconstruction of tracheal defect in rabbits].

OBJECTIVE

To investigate the feasibility of polypropylene mesh (PPM) coated with SIS to reconstruct tracheal defect and the efficiency of SIS in improving epithelialization of the reconstructed trachea and reducing the postoperative complications.

METHODS

Twelve New Zealand white rabbits were chosen and divided randomly into 2 groups: PPM reconstruction group (n=6) and SIS-PPM reconstruction group (n=6). A tracheal full defect with a size of 1.2 cm x 0.6 cm was created. A PPM coated with SIS of 1.4 cm x 0.8 cm was inserted to the defect in SIS-PPM reconstruction group, pure PPM of 1.4 cm x 0.8 cm in PPM reconstruction group. Complications such as death, local inflammation, tracheal stenosis and subcutaneous emphysema were documented. After 4, 8 and 12 weeks, tracheal histological examination and SEM examination were performed.

RESULTS

In SIS-PPM reconstruction group, all animals survived at the end of the experiment, no infection, subcutaneous emphysema and breathing difficulties occurred. In PPM reconstruction group, there was 2 deaths because of infection of lumina and suffocation after 6 and 18 days of implantation; all rabbits had local subcutaneous emphysema. The histological examination showed that there was no obvious granulation tissue and scar in two groups and that the mucous membrane and cilia grew more normally in SIS-PPM reconstruction group than in PPM reconstruction group. SEM observation: At 8 weeks after implantation, most of the reconstructed area of the trachea in SIS-PPM reconstruction group was covered by relatively mature cilia; the corresponding area in PPM reconstruction group was covered by the naive cilia. At 12 weeks after implantation, the cilia in SIS-PPM reconstruction group grew orderly without obvious secretion adherence; while the cilia in PPM reconstruction group grew in a disorderly manner and were attached by an abundance of secretion.

CONCLUSION

Good epithelial regeneration can be achieved after repair of tracheal defect using PPM coated with SIS. SIS can promote regeneration of ciliated epithelium, decrease postoperative complications, such as subcutaneous emphysema. It may be a prospective biomaterial for circumferential tracheal defect reconstruction clinically.