Express: The Effect of Age on Resistance to Distraction Following Tracheal Anastomoses With Two Suture Patterns in Cats

Objectives: To assess the effect of age on the ability of tracheal anastomoses in 24 feline cadaveric tracheae that were performed with two suture patterns to sustain distraction. Materials and Methods: Tracheae were obtained from 16 immature and 8 adult cats and were divided into 3 groups. Each trachea underwent end-to-end annular ligament anastomosis using a simple continuous pattern with a 4/0 polypropylene suture on a round-body needle. In one immature group, 3 simple interrupted tension-relieving sutures were additionally placed. The samples were tested with a tensiometer set at a drop head speed of 50 mm/min, and failure during distraction was defined by tissue pull-through or suture material failure. The force and elongation at failure were compared among groups. Results: Tracheal anastomoses in immature cats failed at lower forces (11.49 ± 1.30 N) compared to those with tension-relieving sutures and to adult cats (19.74 ± 4.55 N and 18.02 ± 1.28 N, respectively) [P < 0.001]. Tracheae from both immature groups sustained greater elongation (46.60 ± 0.06% and 46.53 ± 0.06%) compared to those from the adult group (33.85 ± 0.11%) [P= 0.017 and 0.09, respectively]. Conclusions and relevance: Tracheal anastomoses with tension-relieving sutures in immature cats and anastomoses in adult cats showed greater resistance compared to immature cats without tension–relieving sutures. Tracheae from immature cats showed greater elasticity compared to adult cats. Immature cats may resist longer tracheal resection than adult cats, but reinforcement techniques are necessary to improve resistance to tension.