The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Feb 2019
Impact of patient-specific morphologies on sinus flow stasis in transcatheter aortic valve replacement: An in vitro study.
The goal of this study is to evaluate how sinus flow patterns after transcatheter aortic valve replacement in realistic representative patient roots vary. Sinus flow can affect transcatheter aortic valve operation and likely leaflet thrombosis occurrence due to stasis and poor washout. How the interaction between transcatheter aortic valve and representative patient aortic roots affects sinus hemodynamics is important to establish for future individualization of transcatheter aortic valve replacement therapy. ⋯ Sinus flow dynamics are highly sensitive to aortic root characteristics and transcatheter aortic valve aortic root interaction. Differences in sinus-flow washout and stasis regions between representative patient models may be reflected in different risks of leaflet thrombosis or valve degeneration.
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J. Thorac. Cardiovasc. Surg. · Feb 2019
Multicenter StudyIntervention for arch obstruction after the Norwood procedure: Prevalence, associated factors, and practice variability.
Arch obstruction after the Norwood procedure is common and contributes to mortality. We determined the prevalence, associated factors, and practice variability of arch reintervention and assessed whether arch reintervention is associated with mortality. ⋯ Interdigitation of the distal aortic anastomosis during the Norwood procedure decreased the risk of arch reintervention. Surgical arch reintervention is more definitive than transcatheter. Arch reintervention after the Norwood procedure is not associated with increased mortality. Serial surveillance for arch obstruction, integrated with changes in right ventricular function and tricuspid valve regurgitation, is recommended after the Norwood procedure to improve outcomes.
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J. Thorac. Cardiovasc. Surg. · Feb 2019
A comparison of aortic root measurements by echocardiography and computed tomography.
The aim of the study is to evaluate an optimal way to assess the dimensions of the aortic root and each of the sinuses of Valsalva and examine how a single measurement in 1 plane (echocardiography or 2-dimensional computed tomography) can underestimate the maximum dimension of the aortic root. ⋯ The difference in the measurements of the minimum and maximum aortic root dimensions is significant and may exceed 20 mm, especially in patients with bicuspid aortic valves. Therefore, aortic root dimensions can be significantly underestimated with the measurement (echocardiography, computed tomography angiography) performed in only 1 plane.
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J. Thorac. Cardiovasc. Surg. · Feb 2019
Stent and leaflet stresses in 26-mm, third-generation, balloon-expandable transcatheter aortic valve.
Transcatheter aortic valve replacement has proven successful in treating intermediate-risk, high-risk, and inoperable patients with severe aortic stenosis. Third-generation, balloon-expandable transcatheter aortic valves were developed with an outer sealing skirt to reduce paravalvular leakage. As transcatheter aortic valve replacement use expands, long-term durability questions remain. Valve design influences durability, where regions of increased leaflet stress are vulnerable to early degeneration. However, third-generation transcatheter aortic valve stresses are unknown. Our goals were to determine the stent and leaflet stresses of third-generation, balloon-expandable transcatheter aortic valves. ⋯ Stress analysis of the 26-mm SAPIEN 3 valve using exact geometry from high-resolution scans demonstrated that peak stresses for both transcatheter aortic valve stent and leaflets were present at commissural tips where leaflets were attached. These regions would be most likely to initiate degeneration. The Dacron skirt had minimal effect on stresses on leaflets and stent.
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J. Thorac. Cardiovasc. Surg. · Feb 2019
Comparative StudyInfluence of aortic stiffness on ventricular function in patients with Fontan circulation.
Elastic properties of the thoracic aorta are responsible for buffering systemic afterload, and may be particularly important in patients with Fontan circulation, in whom heart failure is a major source of attrition. The purpose of this study was to characterize regional stiffness in the ascending and descending aorta in patients with hypoplastic left heart syndrome and single left ventricle morphology after Fontan operation by cardiac magnetic resonance imaging, and to assess whether changes in aortic stiffness are associated with the ventricular function. ⋯ Aortic stiffness is most elevated in patients with hypoplastic left heart syndrome, yet patients with single left ventricle morphology show signs of abnormal stiffness as well in the form of reduced aortic strain. Stiffness indices measured in the ascending aorta were associated with overall ventricular function and measures of aortoventricular coupling in both patient populations.