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The aim of this work is to determine mechanical properties of interfaces between layers of the human thoracic aortic wall with early stages of atherosclerosis lesions. Circumferential (n = 48) and axial (n = 15) specimens have been prepared and the mechanical properties of the interfaces between the layers have been determined on the basis of the peeling test. The results show that the mechanical and dissection properties of the interfaces between the layers depend on the direction of the tests. The results confirm that the early stage of atherosclerosis does not affect the mechanical parameters of the layer interfaces and does not affect resistance of the vessel wall to delamination.

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Esophageal elongation is one of the methods of long gap esophageal atresia treatment. The aim of the study was to determine the best type of traction suture for esophageal lengthening on an animal model. White Pekin Duck’s esophagi were used as a model (fresh-frozen and thawed). The esophagus was cut in half, then both ends were sutured together and extended on a tensiometer. Tested sutures involved simple suture, suture aided by a single or double clip, and suture aided by pledget (10 samples each). Constant and 2 methods of intermittent traction were also compared. The histological study showed similarities between duck’s and newborn’s esophagus. The highest maximal force was achieved with pledget suture (F = 8.59 N ± 1.45 N), then with double clip (F = 5.74 N ± 1.29 N) and the lowest with single suture (F = 3.80 N ± 0.54 N) (p < 0.001). Pledget suture also allowed for the greatest elongation (p < 0.01). Intermittent traction results in better elongation at the same breaking strength as constant traction (p < 0.05) if traction is maintained during breaks. Reinforced sutures (pledget or double clip) should be taken into consideration in internal traction. When performing traction sutures, it is worth step by step carefully tightening the sliding knot in short periods before its final binding.

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Purpose: 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.