Initial Load Stability of Different Trachea Suture Techniques: Tests on an Ex Vivo Model

Abstract

Objective Tracheal anastomosis can be performed with different suture techniques. In this experimental work, the resilience of anastomotic techniques to pressure and tensile stress was studied. Study Design Ex vivo pig model. Setting Experimental. Subjects and Methods The trachea with the 2 main bronchi in freshly slaughtered pigs was isolated and intubated (CH 8.0). Both main bronchi were closed distally by a stapler. After resection of the trachea, an anastomosis (n = 15 per group) was created: group 1, single interrupted sutures; group 2, continuous running suture; group 3, mixed technique. A continuous tensile stress of 0, 500, 1000, or 1500 g was applied to the preparations. Mechanical ventilation with a maximum pressure of 70 mbar was initiated. The airtightness of the anastomosis was verified by submerging the entire preparation under water. Results At tensile loads of 0.5 and 1.0 kg, all anastomoses created in the single-stitch technique were airtight; at 1.5 kg, 93.3% were without leaks. In the continuous suture technique, the airtightness of anastomoses decreased with increasing tensile load: from 93.3% at 500 g to 73.3% at 1 kg and 66.6% at 1.5 kg ( P = .02 at 1.5 kg). Anastomoses in the mixed technique were airtight in 80% at 500 g, 66.6% at 1 kg, and 46.6% at 1.5 kg ( P = .01 in comparison with single stitches). Conclusion Anastomoses created with single interrupted sutures showed the highest resilience against combined pressure and tensile stress.