pubmed.ncbi.nlm.nih.gov

Is location a significant parameter in the layer dependent dissection properties of the aorta? - PubMed

Is location a significant parameter in the layer dependent dissection properties of the aorta?

Itziar Ríos-Ruiz et al. Biomech Model Mechanobiol. 2022 Dec.

Abstract

Proper characterisation of biological tissue is key to understanding the effect of the biomechanical environment in the physiology and pathology of the cardiovascular system. Aortic dissection in particular is a prevalent and sometimes fatal disease that still lacks a complete comprehension of its progression. Its development and outcome, however, depend on the location in the vessel. Dissection properties of arteries are frequently studied via delamination tests, such as the T-peel test and the mixed-mode peel test. So far, a study that performs both tests throughout different locations of the aorta, as well as dissecting several interfaces, is missing. This makes it difficult to extract conclusions in terms of vessel heterogeneity, as a standardised experimental procedure cannot be assured for different studies in literature. Therefore, both dissection tests have been here performed on healthy porcine aortas, dissecting three interfaces of the vessels, i.e., the intima-media, the media-adventitia and the media within itself, considering different locations of the aorta, the ascending thoracic aorta (ATA), the descending thoracic aorta and the infrarenal abdominal aorta (IAA). Significant differences were found for both, layers and location. In particular, dissection forces in the ATA were the highest and the separation of the intima-media interface required significantly the lowest force. Moreover, dissection in the longitudinal direction of the vessel generally required more force than in the circumferential one. These results emphasise the need to characterise aortic tissue considering the specific location and dissected layer of the vessel.

Keywords: Aortic dissection; Delamination tests; Mixed-mode peel test; Porcine aorta; T-peel test; Tissue characterisation.

© 2022. The Author(s).

PubMed Disclaimer

Conflict of interest statement

All authors declare that they have no conflicts of interest.

Figures

Fig. 1
Fig. 1

Experimental setup and descriptive outline of the experimental tests. (a) shows the dissection of a sample by means of the T-peel test in the Instron BioPuls™ low-force planar-biaxial Testing System. (b) shows the dissection via the mixed-mode peel test in the high precision drive Instron Microtester 5548 system

Fig. 2
Fig. 2

Outline of the considered dimensions to calculate the dissection energy in the T-peel test (a) and mixed-mode peel test (b). (c) shows an example of the obtention of displacement increments Δd in the force/width curves

Fig. 3
Fig. 3

F/w (mN/mm) vs interface separation (mm) of the T-peel test performed in the specimens of the ATA (a), DTA (b) and IAA (c). For each region, the C direction is shown on top and the L one at the bottom. Separation of the IM is shown on the left, of the MA in the centre and the M on the right. Each individual is represented by one color. Data are n = 8, except for ATA IM C (n = 9), DTA IM L (n = 6), MA L (n = 9) and M L (n = 7) and IAA IM C and L (n = 6 and n = 5), MA C and L (n = 5 and n = 7) and M C (n = 7)

Fig. 4
Fig. 4

Averaged mean force/width and standard deviation (a) and dissection energy and standard deviation (b) of the T-peel test. *Statistically significant differences with a p<0.05. **Statistically significant difference, p<0.05, in the separation of the specified interfaces between the ATA and the DTA, as well as the ATA and the IAA, shown this way for graphical purposes

Fig. 5
Fig. 5

F/w (mN/mm) vs interface separation (mm) of the mixed-mode peel test performed in the specimens of the ATA (a), DTA (b) and IAA (c). For each region, the C direction is shown on top and the L one at the bottom. Separation of the IM is shown on the left, of the MA in the centre and the M on the right. Each individual is represented by one color. ATA IM C and L (n = 8 and n = 7), MA C and L (n = 9 and n = 8), M C and L (n = 9 and n = 8). DTA IM C and L (n = 8 and n=9), MA C and L (n = 8 and n = 9), M C and L (n = 10 and n = 9). IAA IM C and L (n = 6), MA C and L (n = 5), M C and L (n = 6 and n = 5)

Fig. 6
Fig. 6

Averaged mean force/width and standard deviation (a) and dissection energy and standard deviation (b) of the mixed-mode peel test. *Statistically significant differences with a p<0.05. **Statistically significant difference, p<0.05, in the separation of the specified interfaces between the ATA and the DTA, as well as the ATA and the IAA, shown this way for graphical purposes

Fig. 7
Fig. 7

Masson’s trichrome histologies of the three dissected interfaces with the T-peel test in the C direction. a–c show separations in the DTA and d–f in the IAA. IM separation is on the left column, MA separation is on the middle and M separation on the right. The different layers are indicated on the images. Scale bar is 50 μm

Similar articles

Cited by

References

    1. Alimohammadi M, Sherwood JM, Karimpour M, et al. Aortic dissection simulation models for clinical support: fluid-structure interaction vs. rigid wall models. Biomed Eng. 2015 doi: 10.1186/s12938-015-0032-6. - DOI - PMC - PubMed
    1. Angouras DC, Kritharis EP, Sokolis DP. Regional distribution of delamination strength in ascending thoracic aortic aneurysms. J Mech Behav Biomed Mater. 2019;98:58–70. doi: 10.1016/j.jmbbm.2019.06.001. - DOI - PubMed
    1. Assar AN, Zarins CK. Ruptured abdominal aortic aneurysm: a surgical emergency with many clinical presentations. Postgrad Med J. 2009;85(1003):268–273. doi: 10.1136/pgmj.2008.074666. - DOI - PubMed
    1. Beller CJ, Labrosse MR, Thubrikar MJ, et al. Finite element modeling of the thoracic aorta: including aortic root motion to evaluate the risk of aortic dissection. J Med Eng. 2008;32(2):167–170. doi: 10.1080/03091900600687672. - DOI - PubMed
    1. BenSaïda A (2021) Shapiro-wilk and shapiro-francia normality tests. (https://wwwmathworkscom/matlabcentral/fileexchange/13964-shapiro-wilk-and-shapiro-francia-normality-tests), MATLAB Central File Exchange Retrieved August 28, 2021

MeSH terms