The repair of tracheal defects using bioabsorbable mesh

This study compares the use of synthetic bioabsorbable mesh with that of non-absorbable mesh in repairing tracheal defects. Two patch windows, each 1 cm x 1 cm, were created on the ventral wall of the cervical trachea in 12 adult mongrel dogs. One window was repaired using a bioabsorbable polyglycolic acid (PGA) mesh graft, and the other using a nonabsorbable Marlex mesh (polypropylene mesh; PP mesh) (C. R. Bard, Inc., Billerica, MA) graft. The dogs were killed at intervals from 1 to 35 weeks after surgery. Macroscopically, there was no difference between the two mesh groups until 3 weeks after surgery. At 6 weeks in the PP mesh group, the connective tissue over the mesh was remarkably thick, and after 9 weeks, constriction by scarlike tissue was evident, as compared with the PGA mesh group, which showed no constriction. Microscopically, epithelium covered the whole mesh in both groups at 6 weeks. However, in the PP mesh group, flat and poorly differentiated cells occupied a large area, and after 9 weeks the height of the epithelial cells in the PP mesh group was less than in the PGA mesh group. Furthermore, in the PP mesh group, nonciliated cells occupied a large area even at 15 weeks, and the submucous connective tissue layer was thicker than in the PGA mesh group after 6 weeks. The results indicate that, from the point of view of wound-healing, bioabsorbable mesh may be more adequate for repairing tracheal defects.