This is a publications repository of Liverpool Heart & Chest NHS Foundation Trust. It contains records of written works by the members of staff and features a mix of journal articles, conference papers and other publications.
For news items, please visit the LHCH News Archive.
Risk Stratification of Postoperative Dyspnoea: Is it Time to Change Practice?
Abah U, Shackcloth M
2019 Oct 17
Bicuspid valve aortopathy is associated with distinct patterns of matrix degradation
Chim YH, Davies HA, Mason D, Nawaytou O, Field M, Madine J, Akhtar R
Journal of thoracic and cardiovascular surgery
2019 Sep 25
OBJECTIVE: To explore the micromechanical, biochemical, and microstructural differences between bicuspid aortic valve aneurysm (BAV-A) and tricuspid aortic valve idiopathic degenerative aneurysm (DA), compared with normal aorta. METHODS: Aortic tissue was obtained from patients undergoing aneurysmal repair surgery (BAV-A; n = 15 and DA; n = 15). Control tissue was obtained from aortic punch biopsies during coronary artery bypass graft surgery (n = 9). Nanoindentation was used to determine the elastic modulus on the medial layer. Glycosaminoglycan, collagen, and elastin levels were measured using biochemical assays. Verhoeff Van Gieson-stained cross-sections were imaged for elastin microstructural quantification. RESULTS: The elastic modulus was more than 20% greater for BAV-A relative to control and DA (signifying a loss of compliance). No significance difference between control and DA were observed. Collagen levels for BAV-A (36.9 ± 7.4 μg/mg) and DA (49.9 ± 10.9 μg/mg) were greater compared with the control (30.2 ± 13.1 μg/mg). Glycosaminoglycan and elastin levels were not significant between the groups. Elastin segments were uniform throughout the control. Aneurysmal tissues had less elastin segments close to the intima and adventitia layers. Both BAV-A and DA had elastin segments compacted in the media; however, elastin segments were highly fragmented in DA. CONCLUSIONS: BAV-A has a greater loss of aortic wall compliance relative to DA and the control. Although elastin levels were equal for all groups, spatial distribution of elastin provided a unique profile of matrix degradation for BAV-A. Elastin compaction within the media of BAV-A may have resulted from the altered hemodynamic pressure against the wall, which could explain for the stiffness of the tissue. Copyright © 2019 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.