IntroductionThere are data that associates abdominal aortic aneurysms (AAA) with an increased prevalence of hernia disease. A possible structural alteration of extracellular matrix may be common in the degenerative process of the aortic wall and the abdominal fascia. ObjectiveDetermine the expression of matrix metalloproteinases-2 (MMP-2) and tissue inhibitor of metalloproteinases-2 (TIMP-2) in aortic wall tissue, abdominal fascia, and plasma of patients undergoing AAA versus patients with aortic occlusive disease (EAO). Material and methodsA pilot, prospective observational study was conducted, in which the protein expression of MMP-2 and TIMP-2 was analyzed in 10 patients with AAA, and in 10 with EAO, using an ELISA technique. Epidemiological data, history of hernias, and AAA diameters were collected. ResultsIn the subgroup of medium sized AAA with a history of hernia, over-expression of MMP-2 was found in fascia, and of TIMP-2 in aorta and fascia. As regards EAO without hernia (MMP-2 fascia: AAA=4.53 [3.11-6.90], EAO=1.87 [1.45-2.90], P=.04; TIMP-2 in aorta: AAA = 72.62 [9.26-161.12], EAO=9.79 [5.55-25.61], P=.04, and TIMP-2 in fascia: AAA=35.24 [13.15-61.08], EAO =4.98 [1.42-18.01], P=.02).The MMP-2 and TIMP-2 was increased in AAA fascia hernia disease compared with EAO without hernia (MMP-2: 4.31 [3.35-6.35] versus 1.87 [1.45-2.90], P=.009, and TIMP-2: 18.73 [7.76-57.97] versus 4.98 [1.42-18.01], P=.08).There was an increased TIMP-2 in the aortic wall, AAA (29.27 [14.05-140.30] vs. EAO 9.79 [6.19-32.74], P=.06). ConclusionsThe MMP-2 and TIMP-2 are increased in aorta and fascia of patients with AAA, especially in the medium size, suggesting a role in the etiology. The increase in MMP-2 and TIMP-2 in the presence of hernia, enhances the idea of a common pathogenic mechanism.
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