Background: It is unclear whether composite Y-grafts can withstand the flow demand of the coronary system at rest and under stress. This study compared the graft flow and flow reserve of the left internal mammary artery (LIMA) intraoperatively and over a 2-year follow-up in single or composite Y-graft configurations using the radial artery (RA).
Methods: One hundred patients who underwent off-pump myocardial revascularization with a composite Y-graft (group 2) were compared with a homogeneous group of 100 patients treated with a single independent LIMA graft on the left anterior descending artery (LAD) (group 1). Intraoperative baseline flow and flow after adenosine infusion into the left ventricle were analyzed. Over a 2-year follow-up, noninvasive longitudinal evaluation of flow was carried out at rest and during maximal hyperemic response by transthoracic Doppler ultrasonography. Final functional evaluation was obtained through a 2-day stress/rest 99mTc-sestamibi myocardial perfusion single-photon emission computed tomographic scan.
Results: The proximal LIMA in a Y-graft configuration showed adaptability to flow dynamics. It had a greater average peak velocity (p = 0.02), flow volume (p < 0.01), and diameter (p < 0.01) than independent single LIMA grafts. Distal flow at rest and during adenosine recruitment was similar between groups both intraoperatively and at all time points of the follow-up. No steal phenomenon occurred at rest, nor was it induced by adenosine in the Y-graft group. Exercise nuclear scintigraphy showed satisfactory exercise tolerance and no inducible significant perfusion defects in both groups.
Conclusions: Left internal mammary artery Y-grafting with the RA is adequate for flow requirements of distal branches at rest and during maximal hyperemia and is able to adapt its dimension to flow demand. Optimal results for RA anastomoses are possible only in arteries with critical stenosis and of good size and quality.
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http://dx.doi.org/10.1016/j.athoracsur.2011.05.092 | DOI Listing |
In Vitro Cell Dev Biol Anim
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Department of Outpatient Service, The Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, 421002, Hunan, China.
The objective of this study is to explore how adipose-derived stem cells (ASCs) regulate mitochondrial structure and function and the impact of this regulation on slowing cellular senescence. HFF-1 cells were induced by HO to establish a cellular senescence model, and ASCs or Mdivi-1 (mitochondrial fission inhibitor) was added. MTT examined the cell proliferation; flow cytometry detected mitochondrial membrane potential as well as apoptosis and cell cycle; kit measured ATP production; ELISA analyzed the levels of interleukin-6 (IL-6), interleukin 1 beta (IL-1β), tumor necrosis factor alpha-like (TNF-α), glutathione (GSH), malondialdehyde (MDA), and superoxide dismutase (SOD); Western blotting and qRT-PCR detected the expression of protein and mRNA levels; and β-galactosidase staining observed the degree of cellular senescence.
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Institute for Medical Engineering and Science, Massachusetts Institute of Technology, MA, Cambridge, USA.
Purpose: Atrial fibrillation (AF) is the most common chronic cardiac arrhythmia that increases the risk of stroke, primarily due to thrombus formation in the left atrial appendage (LAA). Left atrial appendage occlusion (LAAO) devices offer an alternative to oral anticoagulation for stroke prevention. However, the complex and variable anatomy of the LAA presents significant challenges to device design and deployment.
View Article and Find Full Text PDFCardiovasc Eng Technol
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Department of Hydrodynamic Systems, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 1-3, Budapest, 1111, Hungary.
Purpose: The initiation of intracranial aneurysms has long been studied, mainly by the evaluation of the wall shear stress field. However, the debate about the emergence of hemodynamic stimuli still persists. This paper builds on our previous hypothesis that secondary flows play an important role in the formation cascade by examining the relationship between flow physics and vessel geometry.
View Article and Find Full Text PDFMed Biol Eng Comput
January 2025
School of Biomedical Engineering, Shanghai Jiao Tong University, No.1954 Huashan Road, Shanghai, 200030, Shanghai, China.
Previous studies reported baseline state-dependent effects on neural and hemodynamic responses to transcranial ultrasound stimulation. However, due to neurovascular coupling, neither neural nor hemodynamic baseline alone can fully explain the ultrasound-induced responses. In this study, using a general linear model, we aimed to investigate the roles of both neural and hemodynamic baseline status as well as their interactions in ultrasound-induced responses.
View Article and Find Full Text PDFInt J Cardiovasc Imaging
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Translation Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland.
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