FE simulation of human trachea swallowing movement before and after the implantation of an endoprothesis

Background and aimsNowadays interventions associated to the implantation of tracheal stents in patients with airway pathologies, are a very common surgery that in the post-operating period can bear many problems such as migration of the stent, development of granulation tissue at the edges of the stent with overgrowth of the tracheal lumen, or accumulation of secretions inside the prosthesis. Among the movements that trachea carries out, swallowing seems to drive harmful consequences for the tracheal tissues surrounding the prosthesis. In this work a finite element model of a human trachea has been developed and used to analyze its behavior during swallowing.Material and methodsIn the present work, a complete human trachea finite element model based on experimental study was developed. The real swallowing movement of two patients before and after the implantation of Dumon prosthesis was used to simulate and then analyze the effect that the tracheal implant has on the stress response of the trachea and on the physiological capacity to swallow.ResultsIn both studied cases with an implanted Dumon prosthesis, patients showed a decrease of their ability to swallow; one lost 26.4% and the other one 18.9% of their tracheal ascending movements. Besides, the prosthesis implantation caused an increase of the stresses located in the superior contact border between the tracheal wall and the prosthesis. It could be seen that the resulting force equivalent to the elevating tracheal muscle forces for degluting, was around F = 13.5 N for the two patients both before and after the stent implantation.ConclusionThe implantation of a Dumon prosthesis modifies the mechanical response of the trachea altering its stress distribution and its ascending movement.