Maximum length of tracheal autografts in dogs.

When a primary anastomosis of the trachea is not feasible, grafting is required. We assessed the maximum length of tracheal autografts in 25 dogs. We used the autografts in this experimental study to avoid the immunologic complexity of allografts. Sections of cervical trachea ranging in length from 2.4 cm (6 rings) to 5.9 cm (14 rings) were excised and reimplanted as autografts. To increase the blood supply, we wrapped each graft in the greater omentum, which was brought up through the diaphragm. Grafts longer than 4.0 cm (8 to 10 rings) frequently showed stenosis, dissolution, or both in the middle part of the graft as a result of ischemia in that area, as demonstrated by laser blood flowmetry and injection study. We conclude that there is a limit to the length of a tracheal autograft, even if the blood supply has been increased by wrapping with omentum.