# Reconstruction of the Physiological Behavior of Real and Synthetic Vessels in Controlled Conditions
## 4 Discussion  
In our earlier investigations, we demonstrated the ability of an ex vivo bioreactor to recreate hemodynamics in elastic 3D-printed models of abdominal aortic aneurysms [24; 25] and human grafts [22]. In those papers, we showed that our self-made system allows us to successfully track hemodynamic changes in the abdominal aortic aneurysm (AAA) model with thrombus or stent-graft under different hemodynamic conditions. Here, we aimed to verify the accuracy of our platform to simulate the movement of artificial vessels in relation to a real vessel under changing cardiovascular parameters such as heartbeat, ejection fraction, and total peripheral resistance.  
The integration of engineering and medical tools could offer a valuable method for the ex vivo analysis of biomaterials. [26]. Nevertheless, artificial systems have limitations, such as the specificity of their construction, the absence of a pulsating flow [27], or their reliance on animal tissues rather than human tissues [28]. Additionally, while MRI techniques offer data regarding the spatial configuration of vessels, they do not provide information about their stability or rupture [29]. The present research confirms that the Artificial Circulatory Phantom effectively replicates blood hemodynamics, allowing for the recreation of physiological conditions, such as the ejection volume, pulsation frequency, and ejection pressure for iliac arteries and ePTFE vascular prostheses. This corresponds with findings from comparable studies conducted by other researchers [11; 30; 31].  
Significantly, we noted that the achievement of physiological conditions required the utilization of a water environment, an innovative approach with no prior literature precedent for simulating organ tension. For instance, [PERSON] et al. devised a culture system  
Figure 8: Correlation for: (**a**) the iliac arteries for the tortuosity index as function of wall deformation; (**b**) for the ePTFE vascular prosthesis for the tortuosity index as function of wall deformation. Scatterplot graphic; analyzed cases consisted of \(n=120\).  
to replicate hemodynamic conditions in saphenous veins following coronary artery bypass grafting [16; 32]. [PERSON] et al. investigated cellular interactions in pig carotid arteries using an ex vivo system, with flow reconstructed using a peristaltic pump at a constant speed [33]. However, these studies lacked an authentic representation of the heartbeat, which is a distinctive feature of our approach. Similarly, [PERSON] et al. examined abdominal aortic aneurysm displacement using 3D speckle-tracking ultrasound [31], but their horizontal vessel configuration differed from our vertical positioning.  
Moreover, [PERSON] et al. applied a dedicated system for mouse artery stress analysis [34]. [PERSON] et al. studied the transparent part of the cardiac system using 3D particle-tracking velocimetry [35], but their methodology lacked a water environment and the measurement of vessel spatial configuration.  
Taking into account the significance of the vessel's physical properties for the reconstruction of clinical conditions [36; 37], our study is consistent with the observations made by [PERSON] et al. [37], who identified changes in the aortic pressure wave associated with varying aortic stiffness, and [PERSON] et al. [38], who documented the age-related stiffening of the ascending aorta. [PERSON] et al. [39] analyzed the accuracy of the tortuosity index in the left main coronary artery using computational modeling, contrasting with our results, which indicated a good agreement between the experimental and clinical data. Additionally, our study differs from the findings of [PERSON] et al. and [PERSON] et al. [40; 41], who noted higher averages and wider spreads of the WSS values.  
In light of our presented results, we suggest that it is essential to examine other geometric parameters, such as angulations, in our system to accurately predict the occurrence of thrombus or prosthesis movement.