Biomechanical Profiling in Real-Life Abdominal Aortic Aneurysms in Different Clinical Scenarios

The aim of this study was to demonstrate the biomechanical properties in different abdominal aortic aneurysm (AAA) presentations of real-life patients. We used the actual 3D geometry of the AAAs under analysis and a realistic, nonlinearly elastic biomechanical model.

Three patients with different clinical scenarios (R: rupture, S: symptomatic, and A: asymptomatic) with infrarenal aortic aneurysms were studied. Factors affecting aneurysm behavior such as morphology, wall shear stress (WSS), pressure, and velocities were studied and analyzed using steady state computer fluid dynamics using SolidWorks (Dassault Systems SolidWorksCorp., Waltham, Massachusetts).

When analyzing the WSS, Patient R and Patient A had a decrease in the pressure in the bottom-back region compared with the body of the aneurysm. In contrast, WSS values appeared to be the most uniform across the entire aneurysm in Patient S. Furthermore, Patient A had focal small surface regions with high WSS values. The overall WSS in the unruptured aneurysms (Patient S and Patient A) were a lot higher than in the ruptured 1 (Patient R). All 3 patients showed a pressure gradient, being high at the top and low at the bottom. All patients had pressure values 20 times smaller in the iliac arteries compared with the neck of the aneurysm. The overall maximum pressure was similar between Patient R and Patient A, higher than the maximum pressure of Patient S.

Computed fluid dynamics was implemented in anatomically accurate models of AAAs in different clinical scenarios for obtaining a broader understanding of the biomechanical properties that determine the behavior of AAA. Further analysis and the inclusion of new metrics and technological tools are needed to accurately determine the key factors that will compromise the integrity of the patient's aneurysms anatomy.