Pitt | Swanson Engineering
Biomechanical Modeling of Thoracic and Abdominal Aortic Aneurysms


Our laboratory has had a long-standing interest in the biomechanical evolution of the aorta from the native to the aneurysmal state. Our initial computational work focused on the abdominal aortic aneurysm, which allowed for easy conversion of clinical images to a three-dimensional tubular model. Notably, we include the intraluminal thrombus (ILT) in our model, which is unique to abdominal aneurysms and modifies the response to the biomechanical environment. We have also begun generating three dimensional models of the more geometrically complex thoracic aorta, including the ascending portion and the aortic arch.

To provide important parameters to enter into our computational model, we have performed biomechanical testing of aneurysmal human thoracic and abdominal aortas from open repair surgeries, as well as samples of ILT. With our experimental data, we have developed a biomechanics-based rupture potential index, which can be calculated directly from patient-specific aortic geometries. For the case of abdominal aneurysm, we employ our well-cited constitutive models to noninvasively estimate wall strength based on patient age, gender, and local variables such as ILT thickness, diameter, etc. We are now beginning to translate these same techniques to the case of thoracic aneurysms.                
Related publications  

1.    Pasta S, Phillippi JA, Gleason TG, Vorp DA, “ Effect of Aneurysm on the Mechanical Dissection Properties of the Human Ascending Aorta”, Journal of Thoracic and Cardiovascular Surgery, 2012 Feb;143(2):460-7, PMID 21868041

2.    Pasta S, Cho JS, Dur O, Pekkan K, Vorp DA, “Computer modeling for the prediction of thoracic aortic stent graft collapse”, Journal of Vascular Surgery, 2013 May; 57(5):1353-61, PMID 23313184,

3.    Pasta S, Rinaudo A, Luca A, Pilato M, Scardulla C, Gleason TG, Vorp DA, “Difference in hemodynamic and wall stress of ascending thoracic aortic aneurysms with bicuspid and tricuspid aortic valve”, J Biomech., 2013 Jun; 46(10):1729-38, PMID: 23664314, PMCID: PMC4016719

4.    Pichamuthu JE, Phillippi JA, Cleary DA, Chew DW, Hempel J, Vorp DA, Gleason TG, “Differential Tensile Strength and Collagen Composition in Ascending Aortic Aneurysms by Aortic Valve Phenotype”, Annals of Thoracic Surgery, 2013 Dec; 96(6):2147-54, PMID 24021768, PMCID: PMC4016718