A pre-operative planning for endoprosthetic human tracheal implantation: a decision support system based on robust design of experiments

Abstract

Swallowing depends on physiological variables that have a decisive influence on the swallowing capacity and on the tracheal stress distribution. Prosthetic implantation modifies these values and the overall performance of the trachea. The objective of this work was to develop a decision support system based on experimental, numerical and statistical approaches, with clinical verification, to help the thoracic surgeon in deciding the position and appropriate dimensions of a Dumon prosthesis for a specific patient in an optimal time and with sufficient robustness. A code for mesh adaptation to any tracheal geometry was implemented and used to develop a robust experimental design, based on the Taguchi's method and the analysis of variance. This design was able to establish the main swallowing influencing factors. The equations to fit the stress and the vertical displacement distributions were obtained. The resulting fitted values were compared to those calculated directly by the finite element method (FEM). Finally, a checking and clinical validation of the statistical study were made, by studying two cases of real patients. The vertical displacements and principal stress distribution obtained for the specific tracheal model were in agreement with those calculated by FE simulations with a maximum absolute error of 1.2 mm and 0.17 MPa, respectively. It was concluded that the resulting decision support tool provides a fast, accurate and simple tool for the thoracic surgeon to predict the stress state of the trachea and the reduction in the ability to swallow after implantation. Thus, it will help them in taking decisions during pre-operative planning of tracheal interventions.

Model reduction methodology for computational simulations of endovascular repair

“…The target was the agreement between the applied displacement ( ) and the reaction force (RF) for SG and SM models. Statistical data processing was applied on the RF results, to determine: the effects of the factors, the interactions between factors and the influence percentage of each factor with respect to the target variable [23][22].…”

Predictive Models with Patient Specific Material Properties for the Biomechanical Behavior of Ascending Thoracic Aneurysms

“…30 It is always important to verify the uniqueness of the obtained solution. 3 Different candidates for the metric may be local deformations, 54 strains, 17 cross section areas or volumes. 17,18,27,30 Few have used the volume occupied by a given constituent, because most soft tissues are incompressible and do not show bulk volume variations above the resolution of imaging techniques.…”

Simulation of swallowing dysfunction and mechanical ventilation after a Montgomery T-tube insertion

“…These are normally focused on quantifying particles deposition for aerosol techniques Balashazy et al 1996;Nowak et al 2003), on the development of analytical models simulating an isolated tracheal ring (Holzhäuser and Lambert 2001), on analyzing the mechanism of mucosal folding that explains the difference in airway narrowing between asthmatic and control airways (Wiggs et al 1997), or on tracheal finite element models used to predict the behavior of animal (Costantino et al 2004) or human trachea (Gustin et al 1996;Perez del Palomar et al 2010;Trabelsi et al 2011Trabelsi et al , 2014Perez del Palomar et al 2010) with and without an inserted prosthesis. While some studies use structural simulations on real human geometries (Perez del Palomar et al 2010;Trabelsi et al 2011Trabelsi et al , 2012Trabelsi et al , 2014 other studies solve the computational fluid dynamics (CFD) problem applied to approximate (Calay et al 2002;Nowak et al 2003;Ma and Lutchen 2006) or real (Tawahai et al 2004;Gemci et al 2008;Luo and Liu 2008;Wall et al 2010) tracheal geometries. Only few studies have been recently oriented to the coupling between fluid and solid.…”