Heterogeneity of Tensile Strength and Matrix Metalloproteinase Activity in the Wall of Abdominal Aortic Aneurysms

摘要: Purpose To measure the tensile strength of aneurysm wall and matrix metalloproteinase (MMP) activity in similar samples aortic tissue. Methods Detailed mechanical testing was conducted on 124 standardized specimens harvested from 24 patients undergoing elective repair. The intrasac pressure required to cause rupture calculated based upon Law Laplace. In addition, MMP-2 9 were assayed these specimens. Sixty nonaneurysmal aorta 6 cadaveric organ donors served as controls. Intrasubject intersubject variations analyzed. Results specimens, Young's modulus 1.80x10(6) N/m(2), load at break 6.36 N, strain 0.30, ultimate 0.53x10(6) N/ m(2), MMP 312 for 460 MMP-9. controls, circumferential measurements a 1.82x10(6) 5.43 0.29, 0.61x10(6) 395 2019 Longitudinal controls 1.38x10(6) 11.39 0.33, 1.30x10(6) N/m(2). Intra variation all parameters very high. Based lowest measured each aneurysm, varied 142 982 mmHg. Conclusions Localized "hot spots" hyperactivity could lead focal weakening relatively low levels intraluminal pressure. These data suggest that sac is just important tension determining risk rupture. Moreover, observations may explain why some small aneurysms larger do not. Assessment computation or measurement stress be subject error inaccuracy due strength.