Phil. Trans. R. Soc. A (2010) 368, 2881–2896 doi:10.1098/rsta.2010.0092 Patient-specific models of human trachea to predict mechanical consequences of endoprosthesis implantation BY A. PÉREZ DEL PALOMAR 1,2,3,∗ , O. TRABELSI 1,2,3 , A. MENA 1,2,3 , J. L. LÓPEZ-VILLALOBOS 4 , A. GINEL 4 AND M. DOBLARÉ 1,2,3 1 Group of Structural Mechanics and Materials Modeling, Aragón Institute of Engineering Research (I3A), Universidad de Zaragoza (Spain), C/Maria de Luna 3, 50018 Zaragoza, Spain 2 Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), C/Maria de Luna 11, 50018 Zaragoza, Spain 3 Aragón Institute of Health Sciences, and 4 Department of Thoracic Surgery, Hospital Virgen del Rocío, Seville, Spain Nowadays, interventions associated with the implantation of tracheal prostheses in patients with airway pathologies are very common. This surgery may promote problems such as migration of the prosthesis, 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 the trachea carries out, swallowing seems to have harmful consequences for the tracheal tissues surrounding the prosthesis. In this work, a finite-element-based tool is presented to construct patient-specific tracheal models, introducing the endotracheal prosthesis and analysing the mechanical consequences of this surgery during swallowing. A complete description of a patient-specific tracheal model is given, and a fully experimental characterization of the tracheal tissues is presented. To construct patient-specific grids, a mesh adaptation algorithm has been developed and the implantation of a tracheal prosthesis is simulated. The ascending deglutition movement of the trachea is recorded using real data from each specific patient from fluoroscopic images before and after implantation. The overall behaviour of the trachea is modified when a prosthesis is introduced. The presented tool has been particularized for two different patients (patient A and patient B), allowing prediction of the consequences of this kind of surgery. In particular, patient A had a decrease of almost 30 per cent in his ability to swallow, and an increase in stresses that were three times higher after prosthesis implantation. In contrast, patient B, who had a shorter trachea and who seemed to undergo more damaging effects, did not have a significant reduction in his ability to swallow and did not present an increase in stress in the tissues. In both cases, there are clinical studies that validate our results: namely, patient A underwent a further intervention whereas the outcome of patient B’s ∗ Author for correspondence (amaya@unizar.es). One contribution of 13 to a Theme Issue ‘The virtual physiological human: computer simulation for integrative biomedicine II’. This journal is © 2010 The Royal Society 2881