Healing process after total cricoidectomy and laryngotracheal reconstruction: endoscopic and histologic evaluation in a canine model

Objective: The surgical procedure for subglottic stenosis is technically challenging when the vocal cords are involved and concomitant management for glottic involvement is required. After total cricoidectomy and laryngotracheal anastomosis, T-tube placement for 3 to 6 months is recommended. Bone grafts might shorten this period. We report the histologic and endoscopic changes after total cricoidectomy with or without bone grafts in a canine model to suggest an appropriate period for T-tube placement and the necessity for bone grafts.

Methods: Ten dogs underwent total cricoidectomy and laryngotracheal anastomosis with or without bone grafts harvested from the ribs. Endoscopic examination was performed monthly, and 1 dog from both groups was humanely killed at 1, 2, 3, 6, and 12 months. The T-tube was removed before death in the dogs killed at 1, 2, and 3 months and at 3 and 6 months in those killed at 6 and 12 months, respectively.

Results: Endoscopically, the glottic opening was in good condition in all dogs, except for 1 that had glottic stenosis. Histologically, active lymphocyte infiltration was observed in dense collagen fibers at the anastomosis at 1 month. At 2 and 3 months, fibroblasts were evident, suggesting active collagen fiber production. At 6 and 12 months, the collagen fibers had become looser. The bone grafts were intact and did not influence the surrounding tissue.

Conclusions: In the canine model, 6 months of T-tube placement is probably sufficient; however, 3 months of placement might not be. Additionally, no difference was found between the dogs with and without a bone graft.