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The layer-specific biomechanical properties of dissecting ascending aortic aneurysm (Stanford type A of dissection)

Kozuń Marta, Kaczorowski Maciej, Haloń Agnieszka

Acta of Bioengineering and Biomechanics

2022

Vol. 24, no. 2

3--14

The aims of this paper was the analysis of the mechanical properties of dissected wall of the ascending aortic aneurysm (n = 12). Methods: All aortas were collected from men (mean age: 48 ± 12 years, mean diameter of the aneurysm: 49 mm ± 4 mm). The mechanical properties were determined based on directional tensile test. The biomechanical assay was complemented by conducting histological analysis (hematoxylin and eosin, Mallory’s trichrome, Azan stain). Results: The highest values (median) of failure Cauchy stress, failure force, Young’s modulus and stiffness coefficient were obtained for the adventitia (max = 1.40 MPa, Fmax = 4.05 N, E = 26.11 MPa, k = 1.06 N/mm). Conclusions: The results indicate that the mechanical function of the adventitia in healthy tissue and dissected ascending aorta aneurysm is the same, i.e., it protects the vessel against destruction. The failure Cauchy stresses found in the media and intima are comparable and amounted to 0.23 and 0.21 MPa, respectively. The results indicate that dissection affects the mechanical properties of ascending aorta wall layers. The mechanical loads are probably transferred within the dissected aneurysmal wall not only through the media, but also through the intima.

Effect of dissection on the mechanical properties of human ascending aorta and human ascending aorta aneurysm

Kozuń Marta, Płonek Tomasz, Jasiński Marek, Filipiak Jarosław

Acta of Bioengineering and Biomechanics

2019

Vol. 21, no. 2

127--134

The aim of the presented work is to determine (i) mechanical properties of the ascending aorta wall (DAA) and the wall of the ascending aortic aneurysm (DAAA), in which spontaneous dissection resulting from the evolving disease occurred, and (ii) the strength of the interface between the layers in the above-mentioned vessels. Methods: The mechanical tests were divided into two steps. In the first step the mechanical properties of the of DAA and DAAA walls were examined on the basis of uniaxial stretching until rapture. In the next step the mechanical parameters of the interface between layers of DAA and DAAA walls were determined by the peeling test. Results: Higher values of tensile strength (max) and Young’s modulus (E) were obtained for the DAAA group, to which the dissecting wall of the ascending aortic aneurysm was classified. For circumferential samples, the difference between the DAAA and DAA groups was 39% in the case of tensile strength and 70% in the case of the Young’s modulus. Conclusions: Summarizing, the studies performed showed that the dissection process is different in the case of the ascending aortic aneurysm wall and the ascending aorta wall. The wall of the ascending aortic aneurysm is more susceptible to dissection, as evidenced by lower values of the mechanical parameters of the interface between the intima and the media-adventitia complex. The obtained results of mechanical properties tests confirm that dissection and aneurysm should be treated as separate disease entities that may coexist with each other.

Krew jako materiał diagnostyczny w toksykologii sądowej

Szopa M., Prudlak K., Zawadzki M., Markowska J., Piekoszewski W., Pędlowski M., Futoma-Kołoch B.

Laboratorium - Przegląd Ogólnopolski

2015

nr 9-10

77--80

Analiza toksykologiczna może być wykonywana dla każdego rodzaju próbki, jednak najczęstszym materiałem do badań toksykologicznych jest krew, nierzadko analizowana wraz z innymi płynami ustrojowymi, a w przypadku toksykologii sądowej – tkankami pobranymi w czasie sekcji zwłok. Obecnie jednym z najważniejszych zadań leżących w sferze zainteresowania toksykologa sądowego jest analiza substancji uzależniających.

The toxicological analysis may be performed for each type of sample, but the most common material for toxicological studies is the blood, often analyzed along with other body fluids and tissue collected during autopsy. One of the most important tasks falling within the sphere of the forensic toxicologist interest is the analysis of addictive substances.