CFD to Elucidate Aortofemoral Artery Hemodynamics for AAA Geometric Variants

Introduction

Abdominal Aortic Aneurysm (AAA) is a pathological condition characterized by the dilation of the aorta, the largest artery in the human body, in the abdominal region. AAA is a severe medical condition and can lead to fatal complications such as rupture, causing massive internal bleeding. Hemodynamic factors, such as blood flow velocity and pressure, play a crucial role in the progression and rupture of AAA. Understanding the impact of AAA shape on hemodynamics is crucial for better diagnosis, prognosis, and treatment of this life-threatening disease. Recently, a team of researchers published an article titled “Influence of abdominal aortic aneurysm shape on hemodynamics in human aortofemoral arteries: A transient open-loop study” in the journal Physics of Fluids. In this blog post, we will discuss the key findings of this research and its potential implications.

Background

AAA is a complex disease that affects millions of people worldwide. The traditional clinical approach to diagnose and monitor AAA involves imaging techniques such as computed tomography (CT) and ultrasound. However, these techniques primarily focus on the size and location of the aneurysm and provide limited information on hemodynamics. Hemodynamics is a branch of physics that deals with the study of blood flow in the human body. Understanding the hemodynamic factors associated with AAA can provide valuable information about the disease’s progression and potential complications.

Research Methodology

The research team utilized a computational fluid dynamics (CFD) approach to simulate blood flow in human aortofemoral arteries with different shapes of AAA. The study used patient-specific models of aortofemoral arteries with varying AAA shapes, such as fusiform, saccular, and complex. The researchers simulated the blood flow under transient open-loop conditions, which mimic the pulsatile nature of blood flow in the human body. The team used several hemodynamic parameters, such as wall shear stress (WSS), pressure, and velocity, to evaluate the impact of AAA shape on hemodynamics.

Key Findings

The research found that AAA shape has a significant impact on hemodynamics in human aortofemoral arteries. The study revealed that saccular and complex AAA shapes were associated with higher WSS and pressure in the aneurysm sac compared to fusiform AAA shapes. The complex AAA shapes, in particular, were found to be associated with complex flow patterns, such as recirculation zones, which can lead to the formation of thrombus (blood clots). The research team also found that the location of the AAA in the aorta can significantly impact the hemodynamics in the aortofemoral arteries. AAA located near the bifurcation of the aorta was found to be associated with higher pressure and WSS in the iliac arteries compared to AAA located further up in the abdominal aorta.

Implications

The research has significant implications for the diagnosis, monitoring, and treatment of AAA. The findings suggest that AAA shape and location play a critical role in hemodynamics and potentially lead to complications such as thrombus formation. The study highlights the importance of incorporating hemodynamic factors into the clinical assessment of AAA to improve patient outcomes. The research also suggests that personalized treatment approaches, such as stent grafts, should consider the AAA’s shape and location to achieve optimal outcomes.

Conclusion

The research published in Physics of Fluids sheds light on the impact of AAA shape on hemodynamics in human aortofemoral arteries. The findings have significant implications for the clinical assessment and treatment of AAA. The study underscores the importance of incorporating hemodynamic factors into the diagnosis and monitoring of AAA to achieve better patient outcomes. Future research in this area can further investigate the relationship between AAA shape and hemodynamics and potentially identify new diagnostic and treatment approaches. The use of computational modeling techniques, such as CFD, can help predict potential complications associated with AAA and personalize treatment plans for patients. Overall, this research highlights the importance of interdisciplinary approaches to understanding complex medical conditions and improving patient outcomes.

Study DOI: 10.1063/5.0139085

Engr. Dex Marco Tiu Guibelondo, BS Pharm, RPh, BS CpE

Editor-in-Chief, PharmaFEATURES