Use of β-tricalcium phosphate grafts for Airway reconstruction in rabbits: A pilot study

To assess the safety and feasibility of using β-tricalcium phosphate grafts in airway reconstruction in rabbits.

Interventional animal study.

Ten New Zealand White rabbits underwent division of the anterior cricoid cartilage with interposition of a graft sculpted from β-tricalcium phosphate blocks. Grafts were secured with sutures or were self-retaining. Rabbit larynges were harvested according to the following schedule: one at 1 week, one at 3 months, and two each at 2 weeks, 4 weeks, 6 months, and 1 year after graft implantation. Specimens were evaluated grossly for overall graft incorporation. Sections through the graft substance were prepared for histology. All sections were reviewed by a pathologist for evidence of vascular ingrowth, granulation tissue, inflammation, epithelialization, and graft resorption.

There were no major postoperative complications. Gross examination revealed persistent widening of the airway at the level of graft placement. Histologic evaluation of the larynges showed growth of new blood vessels within all specimens and absence of significant granulation tissue near the airway lumen. The graft was at least partially covered by an epithelium in seven of the 10 specimens. Evidence of graft resorption was present as early as 4 weeks after implantation, with replacement of the graft substance by fibrous tissue, fatty tissue, bone, or cartilage.

β-tricalcium phosphate grafts can be used safely in airway reconstruction procedures in rabbits. Further research is necessary to demonstrate its safety in human airway reconstruction in addition to further clarifying the processes of graft resorption and integration.

NA Laryngoscope, 126:E255-E260, 2016.