Τίτλος:
Effect of impaired vasa vasorum flow on the structure and mechanics of
the thoracic aorta: implications for the pathogenesis of aortic
dissection
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Objective: To investigate the alterations of structure and mechanical
properties of the aortic wall, resulting from impairment of vasa vasorum
Row. Methods: Eight healthy Landrace pigs were subjected to interruption
of vasa vasorum how to the upper segment of their descending thoracic
aorta. Under sterile conditions, the periaortic tissue was excised and
the contiguous intercostal arteries were ligated. Ten sham-operated pigs
were used as controls. Fifteen days postoperatively, the animals were
sacrificed and their upper descending thoracic aortas were removed.
Histology, and collagen and elastin content determination by image
analysis technique were performed. Mechanical analysis of aortic strips
was carried out with a uniaxial tension device and stress-strain curves
were obtained. Results: In contrast to normal aortic walls of the
control group, histology of the avascular aortas revealed severe
ischemic necrosis of the outer media along with abnormal straightening
of the elastin and collagen fibers, without significant collagen and
elastin content changes. The borderline between the outer ischemic and
inner non-ischemic media was sharp, and an outset of dissection was
observed at this point. Mechanical analysis showed that at the same
level of strain, the ischemic aorta was significantly stiffer at both
low (P = 0.03) and high strains (P = 0.003). Conclusions: Impairment of
blood supply to the thoracic aorta leads to abnormal morphology of
elastin and collagen fibers of the outer media, resulting in increased
aortic stiffness under a wide range of stresses. In the clinical
setting, decreased vasa vasorum flew, reportedly occurring in arterial
hypertension, may increase the stiffness of the outer media of the
thoracic aorta and produce interlaminar shear stresses, contributing to
the development of aortic dissection. (C) 2000 Elsevier Science B.V. All
rights reserved.
Συγγραφείς:
Angouras, D
Sokolis, DP
Dosios, T
Kostomitsopoulos, N and
Boudoulas, H
Skalkeas, G
Karayannacos, PE
Περιοδικό:
European Journal of Cardio-Thoracic Surgery Supplements
Εκδότης:
ELSEVIER SCIENCE BV
Λέξεις-κλειδιά:
aorta; elasticity; vasa vasorum; ischemia; dissection
DOI:
10.1016/S1010-7940(00)00382-1
