Isolated human pulmonary artery structure and function pre‐ and post‐cardiopulmonary bypass surgery
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Background Pulmonary dysfunction is a known complication after cardiac surgery using cardiopulmonary bypass, ranging from subclinical functional changes to prolonged postoperative ventilation, acute lung injury, and acute respiratory distress syndrome. Whether human pulmonary arterial function is compromised is unknown. The aim of the present study was to compare the structure and function of isolated and cannulated human pulmonary arteries obtained from lung biopsies after the chest was opened (pre–cardiopulmonary bypass) to those obtained at the end of cardiopulmonary bypass (post–cardiopulmonary bypass) from patients undergoing coronary artery bypass graft surgery.
Methods and Results Pre‐ and post–cardiopulmonary bypass lung biopsies were received from 12 patients undergoing elective surgery. Intralobular small arteries were dissected, cannulated, pressurized, and imaged using confocal microscopy. Functionally, the thromboxane mimetic U46619 produced concentration‐dependent vasoconstriction in 100% and 75% of pre‐ and post–cardiopulmonary bypass arteries, respectively. The endothelium‐dependent agonist bradykinin stimulated vasodilation in 45% and 33% of arteries pre‐ and post–cardiopulmonary bypass, respectively. Structurally, in most arteries smooth muscle cells aligned circumferentially; live cell viability revealed that although 100% of smooth muscle and 90% of endothelial cells from pre–cardiopulmonary bypass biopsies had intact membranes and were considered viable, only 60% and 58%, respectively, were viable from post–cardiopulmonary bypass biopsies.
Conclusions We successfully investigated isolated pulmonary artery structure and function in fresh lung biopsies from patients undergoing heart surgery. Pulmonary artery contractile tone and endothelium‐dependent dilation were significantly reduced in post–cardiopulmonary bypass biopsies. The decreased functional responses were associated with reduced cell viability.
Methods and Results Pre‐ and post–cardiopulmonary bypass lung biopsies were received from 12 patients undergoing elective surgery. Intralobular small arteries were dissected, cannulated, pressurized, and imaged using confocal microscopy. Functionally, the thromboxane mimetic U46619 produced concentration‐dependent vasoconstriction in 100% and 75% of pre‐ and post–cardiopulmonary bypass arteries, respectively. The endothelium‐dependent agonist bradykinin stimulated vasodilation in 45% and 33% of arteries pre‐ and post–cardiopulmonary bypass, respectively. Structurally, in most arteries smooth muscle cells aligned circumferentially; live cell viability revealed that although 100% of smooth muscle and 90% of endothelial cells from pre–cardiopulmonary bypass biopsies had intact membranes and were considered viable, only 60% and 58%, respectively, were viable from post–cardiopulmonary bypass biopsies.
Conclusions We successfully investigated isolated pulmonary artery structure and function in fresh lung biopsies from patients undergoing heart surgery. Pulmonary artery contractile tone and endothelium‐dependent dilation were significantly reduced in post–cardiopulmonary bypass biopsies. The decreased functional responses were associated with reduced cell viability.
Date Issued
2016-02-23
Date Acceptance
2016-01-13
Citation
Journal of the American Heart Association, 2016, 5
ISSN
2047-9980
Publisher
American Heart Association
Journal / Book Title
Journal of the American Heart Association
Volume
5
Copyright Statement
© 2016 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
PII: JAHA.115.002822
Subjects
bradykinin
cardiopulmonary bypass
lung
thromboxane
vasoconstriction
vasodilation
Publication Status
Published
Article Number
e002822