The Role of Geometric Parameters in the Prediction of Abdominal Aortic Aneurysm Wall Stress

ObjectiveTo study the correlation between peak wall stress (PWS) and abdominal aorta aneurysm (AAA) geometric parameters in the presence of intraluminal thrombus (ILT).DesignComputational study using finite element analysis.MaterialAAA models were created by three-dimensional (3D) reconstruction of in vivo acquired computed tomography (CT) images from 19 patients.MethodsPWS was evaluated in the presence and absence of ILT. ΔPWS% represents the percentage change in PWS in the presence of ILT. The 3D lumen centrelines were extracted, and the values of torsion, tortuosity and mean curvature were estimated.ResultsA positive correlation was observed between ΔPWS% and relative ILT volume (P = 0.03). PWS in the presence of ILT significantly correlated only with the degree of centerline tortuosity (P = 0.003) and maximum diameter (P < 0.0001). The optimal predictive model for PWS in the presence of ILT was estimated to contain both maximum diameter and centreline tortuosity.ConclusionsSpecific geometric parameters in AAA models in the presence of ILT could serve as potential predictors of elevated PWS. PWS correlated significantly with the maximum diameter and the degree of centreline tortuosity. Centreline tortuosity may become a useful addition to maximum diameter in the decision-making process of AAA treatment.