Viability of single-pedicled tracheal flaps: an experimental study

1. The objective of the present study was to test the viability of tracheal flaps of different widths and lengths for tracheal reconstruction in dogs, as well as the location of their pedicles. 2. Six types of single-pedicled tracheal flaps were prepared in 30 dogs as follows: narrow flaps with upper pedicles, wide flaps with upper pedicles, narrow flaps with lower pedicles, wide flaps with lower pedicles, narrow flaps with side pedicles, and wide flaps with side pedicles. 3. Flap condition was determined on the basis of clinical signs and by tracheoscopic, macroscopic and microscopic examination. 4. No statistically significant difference in viability was observed between narrow and wide flaps or between flaps with upper and lower pedicles, but all were less viable than side-pedicled flaps. 5. Poor coaptation of the flap borders produced deformities of tracheal architecture, with a significant incidence of necrosis occurring in poorly positioned flaps. The presence of poor coaptation was statistically significant in narrow flaps. Focal infection appears to influence the development of necrosis. We did not observe fibrosis or granulation tissue in sufficient amounts to cause significant stenosis of the tracheal lumen. 6. We conclude that single-pedicled tracheal flaps are viable and can be used for tracheal reconstruction when they are prepared with a length-width ratio of 5 to 10.