E. Comellas, F. J. Bellomo, I. Rosales, L. F. del Castillo, R. Sanchez, P. Turon and S. Oller (2018) On the feasibility of the computational modelling of the endoluminal vacuum-assisted closure of an oesophageal anastomotic leakage, Royal Society Open Science, 5:171289, doi:10.1098/rsos.171289.

Abstract: Endoluminal vacuum-assisted closure (E-VAC) is a promising therapy to treat anastomotic leakages of the oesophagus and bowel which are associated with high morbidity and mortality rates. An open-pore polyurethane foam is introduced into the leakage cavity and connected to a device that applies a suction pressure to accelerate the closure of the defect. Computational analysis of this healing process can advance our understanding of the biomechanical mechanisms at play. To this aim, we use a dual-stage finite-element analysis in which (i) the structural problem addresses the cavity reduction caused by the suction and (ii) a new constitutive formulation models tissue healing via permanent deformations coupled to a stiffness increase. The numerical implementation in an in-house code is described and a qualitative example illustrates the basic characteristics of the model. The computational model successfully reproduces the generic closure of an anastomotic leakage cavity, supporting the hypothesis that suction pressure promotes healing by means of the aforementioned mechanisms. However, the current framework needs to be enriched with empirical data to help advance device designs and treatment guidelines. Nonetheless, this conceptual study confirms that computational analysis can reproduce E-VAC of anastomotic leakages and establishes the bases for better understanding the mechanobiology of anastomotic defect healing.

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Download the additional article information here. 
The .zip file contains the PLCd executable, input files and plotting result files used to produce the computational results presented in the main body of the article. The Fortran source code files corresponding to the constitutive model developed in the article are also provided. The complete PLCd source code is available via the "download" tab of this website. Finally, the PLCd manual and a brief tutorial on how to run the problem described in this article are also provided, albeit in Spanish. If you require further clarification, please contact us at plcd@cimne.upc.edu.