Tracheal Anastomosis Leaks Across Suture Techniques and Tensions: A Biomechanical Ex Vivo Study.

ABSTRACT

BACKGROUND: Anastomotic leak after tracheal resection may occur while coughing in the early postoperative period. We investigated the varying effects of suturing technique, stretch, and tension on anastomotic leaks during simulated coughs. METHODS: End-to-end anastomoses were performed using continuous or interrupted sutures on excised porcine larynges. Tracheas were secured to a pressurized system simulating cough forces, submerged in a water bath, and stretched to 1, 2, and 3 cm above baseline. Peak pressure, incomplete cough generation, and observed leakages were recorded. Parameters were analyzed using Analysis of Variance (ANOVA), multiple linear regression, and logistic regression modeling. RESULTS: Peak tension (B = -0.660, p < 0.001) and stretch lengths (B = -0.329, p = 0.006) were associated with variance in peak pressure (R2 = 0.77, F(3,294) = 8.182, p < 0.001). Incomplete coughs increased with higher peak tension (odds ratio [OR] = 15.627, p < 0.001) and stretching to 3 cm above baseline (OR = 4.335, p < 0.007). Similarly, leak occurrences, primarily from the posterior tracheal wall, increased with higher peak tension (OR = 1.787, p < 0.001) and stretching to 3 cm (OR = 2.613, p = 0.017). No significance was identified with suturing technique. CONCLUSION: Interrupted and continuous suture techniques do not differ in anastomotic strength during simulated coughs. Increased peak tracheal tension is associated with a weaker anastomosis, and tracheal stretch to 3 cm was associated with a weaker anastomosis. Our study supports the commonly held clinical belief that, to create a stronger anastomosis, tension should be minimized, and particular attention should be placed at the posterior tracheal wall during closure. LEVEL OF EVIDENCE N/A, Benchtop study Laryngoscope, 2024.