The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Jun 2016
Reduced continuous-flow left ventricular assist device speed does not decrease von Willebrand factor degradation.
Nonsurgical bleeding is a frequent complication of continuous-flow left ventricular assist device (LVAD) support. Abnormal von Willebrand factor (vWF) metabolism plays a major role. However, the relationship between LVAD speed and vWF degradation is unknown. Recent evidence has demonstrated that supraphysiologic shear stress from continuous-flow LVADs accelerates vWF degradation and causes an acquired vWF deficiency and bleeding. To manage LVAD-associated bleeding, it has been proposed that reduced LVAD speed may decrease shear stress and thereby reduce pathologic vWF metabolism. However, there are little published data to support this clinical practice. We tested the hypothesis that reduced continuous-flow LVAD speed decreases vWF degradation. ⋯ Reduced LVAD speed (within the clinical operational range) did not significantly decrease vWF degradation in a mock circulatory loop with human blood. During bleeding events, reduced LVAD speed, itself, may not diminish vWF degradation.
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J. Thorac. Cardiovasc. Surg. · Jun 2016
Lower-extremity complications with femoral extracorporeal life support.
Patients undergoing emergency peripheral arteriovenous extracorporeal life support were evaluated for lower-extremity complications on the basis of the ipsilateral limb perfusion strategy. ⋯ No superficial femoral artery perfusion strategy is associated with a high lower-extremity complication rate. If percutaneous cannulation is performed, then angiographic confirmation of superficial femoral artery run-off is highly recommended. The open superficial femoral artery approach remains a safe alternative to the other strategies.
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J. Thorac. Cardiovasc. Surg. · Jun 2016
Extracellular matrix fiber microarchitecture is region-specific in bicuspid aortic valve-associated ascending aortopathy.
Ascending thoracic aortic aneurysm (ATAA) in patients with bicuspid aortic valve (BAV) commonly dilate asymmetrically compared with patients with tricuspid aortic valve (TAV). This discrepancy in aneurysm geometry led us to hypothesize that microarchitectural differences underlie the observed asymmetric dilatation pattern. The purpose of this study was to characterize the microarchitectural distinctions of the extracellular matrix of the 2 phenotypes with a focus on the proportion of radially oriented elastin and collagen fibers in different circumferential aortic regions. ⋯ The differential pattern of fiber orientation noted between L and N-R regions help explain the unique pattern of greater curvature dilatation of BAV-ATAA. The distinctions noted in matrix microarchitecture may form the basis of differing aneurysm geometries and aortic wall integrities in ATAAs arising in these different valve morphologies.
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J. Thorac. Cardiovasc. Surg. · Jun 2016
EditorialPropensity-score analysis in thoracic surgery: When, why, and an introduction to how.
Propensity score matching is a valuable tool for dealing with observational data and nonrandom treatment assignment, which often results in groups that differ systematically in numerous measured and unmeasured variables. When these systematically different variables are associated with both group assignment and the outcome(s) of interest, bias is introduced. Propensity score matching assigns a propensity for group assignment, which is then used to create 2 groups that are balanced across all possible variables that might influence exposure assignment. When used in the proper conditions, these analytics allow for more accurate and precise estimates of risk for a variety of outcomes.