Biomechanical comparison of porcine mitral leaflets with porcine small intestinal submucosa extracellular matrix

TY - JOUR

T1 - Biomechanical comparison of porcine mitral leaflets with porcine small intestinal submucosa extracellular matrix

AU - Islamagič, Lejla

AU - Tjørnild, Marcell Juan

AU - Carlson Hanse, Lisa

AU - Nygaard, Jens Vinge

AU - Hasenkam, J. Michael

PY - 2023/4

Y1 - 2023/4

N2 - Porcine small intestinal submucosa extracellular matrix (SIS-ECM) used for cardiac valve repair has shown conflicting clinical outcomes with respect to calcification and failure. This may be related to differences in biomechanical properties of the material compared with the host site. The aim of this study was to compare the biomechanical properties of porcine mitral valve leaflets with SIS-ECM. Fresh porcine anterior and posterior mitral leaflet samples were cut radially and circumferentially. Similarly, 2- and 4-layered SIS-ECM were cut in orthogonal directions: length and width. Samples were subjected to a uniaxial tensile test or a dynamic mechanical analysis. Results show that the load of the porcine anterior circumferential leaflet was 39.5 N (2.4-48.5 N), which was significantly higher compared with the 2-layered length SIS-ECM which was 7.5 N (7-7.9 N), and the 4- layered length SIS-ECM which was 7.5 N (7.1-8.1 N) (p < 0.001). The load of the posterior circumferential leaflet was 9.7 N (8.3-10.7 N), which is still significantly higher when compared with the two versions of SIS-ECM. The degree of anisotropy (i.e. the ratio between circumferential-radial and width-length properties) was higher for the anterior- (ratio: 19) and posterior leaflet (ratio: 6) than the 2-layered (ratio: 5.1) and 4-layered SIS-ECM (ratio: 1.9). Especially 2-layered SIS-ECM more closely resembles the posterior mitral leaflet than the anterior mitral leaflet tissue and would be more suitable as a repair material in this position. Additionally, the anisotropic properties of mitral leaflets and SIS-ECM underscore the importance of correct orientation of the implant to ensure optimal reconstruction.

AB - Porcine small intestinal submucosa extracellular matrix (SIS-ECM) used for cardiac valve repair has shown conflicting clinical outcomes with respect to calcification and failure. This may be related to differences in biomechanical properties of the material compared with the host site. The aim of this study was to compare the biomechanical properties of porcine mitral valve leaflets with SIS-ECM. Fresh porcine anterior and posterior mitral leaflet samples were cut radially and circumferentially. Similarly, 2- and 4-layered SIS-ECM were cut in orthogonal directions: length and width. Samples were subjected to a uniaxial tensile test or a dynamic mechanical analysis. Results show that the load of the porcine anterior circumferential leaflet was 39.5 N (2.4-48.5 N), which was significantly higher compared with the 2-layered length SIS-ECM which was 7.5 N (7-7.9 N), and the 4- layered length SIS-ECM which was 7.5 N (7.1-8.1 N) (p < 0.001). The load of the posterior circumferential leaflet was 9.7 N (8.3-10.7 N), which is still significantly higher when compared with the two versions of SIS-ECM. The degree of anisotropy (i.e. the ratio between circumferential-radial and width-length properties) was higher for the anterior- (ratio: 19) and posterior leaflet (ratio: 6) than the 2-layered (ratio: 5.1) and 4-layered SIS-ECM (ratio: 1.9). Especially 2-layered SIS-ECM more closely resembles the posterior mitral leaflet than the anterior mitral leaflet tissue and would be more suitable as a repair material in this position. Additionally, the anisotropic properties of mitral leaflets and SIS-ECM underscore the importance of correct orientation of the implant to ensure optimal reconstruction.

KW - Mitral valve leaflets

KW - anisotropy

KW - dynamical mechanical analysis

KW - small intestinal submucosa extracellular matrix

KW - uniaxial tensile test

KW - Biomechanical Phenomena

KW - Animals

KW - Mitral Valve/surgery

KW - Extracellular Matrix

KW - Swine

U2 - 10.1177/09544119231158248

DO - 10.1177/09544119231158248

M3 - Journal article

C2 - 36882979

SN - 0954-4119

VL - 237

SP - 435

EP - 442

JO - Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine

JF - Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine

IS - 4

ER -