ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

PREOPERATIVE PLANNING SUPPORT SYSTEM FOR HUMAN TRACHEAL
ENDOPROSTHETIC INTERVENTIONS
1. ABSTRACT
O. Trabelsi 1 , J. L. López-Villalobos 2 , M. Doblaré 1
Introduction: Tracheal prosthetic implantation affects these values and the overall
performance of the trachea and, in particular, the ability to swallow and the tracheal
stress distribution. The objective of this work is to develop a tool based on
experimental, numerical and statistical studies to help the surgeon in deciding the
position and appropriate dimensions of the stent for any specific patient in an optimal
time and with sufficient robustness. Method: A code for mesh adaptation to any patient
geometry was implemented to develop a robust experimental design based on Taguchi's
method and the analysis of variance. The regression equations fitting the stress and the
maximal vertical displacement were obtained. For validation, a real patient with Dumon
stent was studied comparing FE and regression results.
Results: The regression results of the vertical displacements and stress distribution on
the tracheal specific patient model are in agreement withthe results found by FE
simulations with a maximum absolute error of 2.1% and 33% respectively. Conclusion:
A tool for statistical human prosthetic swallowing analysis is presented to get, in an
optimal time, response functions for the most important variables of the problem in
terms of a set of patient specific variables. This provides the surgeon a fast, accurate and
simple tool for predicting the stress state and the reduction in the ability to swallow after
implantation, thus helping in taking pre-operative decisions.
2. INTRODUCTION
The increasing use of simulation in medicine has permitted obtaining important data
about mechanical behavior of organs using mathematical formalization and associated
numerical simulation. Various medical problems associated with surgery and trauma
have been identified and numerically solved [1].
Finite element analysis has gradually improved the ability to simulate several clinical
situations, but still fails to sufficiently accurately fit the reality due to several factors
that change from one patient to the other. Therefore, the surgeon's experience allows a
more objective valorization of traumatic disorders as well as the methods used in their
treatment, while currently finite element analyses permit studying biomechanical
problems with a moderate accuracy, in normal and pathological circumstances caused
by traumatisms or degenerations provoked, for example, by a prosthetic implantation
[2-4]. Thus, a coupling of the surgical experience and finite element simulation would
be efficient and beneficent for the medicine in general.
In the specific case of tracheal intervention, the main problems associated to simulations
are the analysis of the patients TACs, the determination of their healthy and
* Olfa Trabelsi {olfa@unizar.es}, Campus rio Ebro, c/ María de Luna s/n, Ed. Betancourt, Dep. Mecánica,
50018, Zaragoza, Spain. Phone: +34 976 76 1912. Fax: +34 976 76 2578
1 Group of Structural Mechanics and Material Modeling (GEMM), Aragon Institute of Engineering
Research (I3A), University of Zaragoza, Spain
2 Hospital Virgen del Rocío, Department of Thoracic Surgery, Seville, Spain