Potential of Current Direct Mechanical Testing Methods in Assessing Intraoperative Samples of Aortic Aneurysm Caused by Uncontrolled Arterial Hypertension.

Materials and Methods: The study experimental material was the resected parts of the aortic aneurysm obtained during aneurysm replacement surgery in a patient with uncontrolled arterial hypertension. The direct mechanical testing methods such as instrumental indentation and uniaxial extension were used. Results: It was shown that by the direct instrumental indentation it is possible to accurately assess and compare the stiffness of all three layers of the aortic wall. In this clinical case, the inner aorta layer was subject to the greatest atherosclerotic damage. In the media area, the values of this indicator were widely scattered, whereas the material was greatly dissected. By uniaxial extension method it is possible to obtain accurate parameters of the vascular wall strength, as well as to assess the stiffness, elasticity, and deformability of the intraoperatively resected aortic tissue. It was found that the aneurysm aortic wall, compared with the non-dilated aortic section, was characterized by a significantly lower strength in both longitudinal (by 4.25 times) and transverse (by 3.75 times) directions. In addition, aneurysm tissues demonstrated a significantly lower elasticity and deformability. Conclusion: The study demonstrated the perspectives and options of using in clinical practice current methods of direct mechanical testing, which makes it possible to obtain more accurate indicators of the strength and elastic-deformative vascular characteristics, to clarify the pathophysiological mechanisms of cardiovascular accidents, and to justify the need for regular monitoring of vascular wall stiffness in clinical practice, in particular in patients with uncontrolled arterial hypertension.