This work was supported by the VA Merit Review #I01 BX000760 (RFK) from the United States (U.S.) Department of Veterans Affairs BLR&#38;D and U.S. Department of Veterans Affairs grant #I01 BX004146 (TAB). We also gratefully acknowledge the support of the University of Minnesota Lillehei Heart Institute. The contents of this work do not represent the views of the U.S. Department of Veterans Affairs of the United States Government.

The Institutional Animal Care and Use Committees (IACUC) of the Minneapolis VA Medical Center and the University of Minnesota have approved all of the animal studies. The current National Institutes of Health (NIH) guidelines for the use and care of laboratory animals were followed.
1. Isolation of mesenchymal stem cells and preparation and characterization of exosomes
<ol>
	<li>Isolation of bone marrow derived mesenchymal stem cells (MSCs)
	<ol>
		<li>Obtain 30-50 mL of ste...

Adjunctive Exosome Therapy: Enhancing Myocardial Recovery Post-CABG Surgery

<ol>
	<li>Dai, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Global,+regional,+and+burden+of+ischaemic+heart+disease+and+its+attributable+risk+factors,+1990-2017:+results+from+the+Global+Burden+of+Disease+Study+2017.">Global, regional, and burden of ischaemic heart disease and its attributable risk factors, 1990-2017: results from the Global Burden of Disease Study 2017.</a> European heart journal. Quality of care &amp; clinical outcomes. 8 (1), 50-60 (2022).</li><li>Tsao, C. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heart+Disease+and+Stroke+Statistics-2022+Update:+A+Report+From+the+American+Heart+Association.">Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association.</a> Circulation. 145 (8), e153-e639 (2022).</li><li>Rahimtoola, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+hibernating+myocardium.">The hibernating myocardium.</a> American Heart Journal. 117 (1), 211-221 (1989).</li><li>Canty, J. M., Fallavollita, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hibernating+myocardium.">Hibernating myocardium.</a> Journal of Nuclear Cardiology. 12 (1), 104-119 (2005).</li><li>Page, B. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Revascularization+of+chronic+hibernating+myocardium+stimulates+myocyte+proliferation+and+partially+reverses+chronic+adaptations+to+ischemia.">Revascularization of chronic hibernating myocardium stimulates myocyte proliferation and partially reverses chronic adaptations to ischemia.</a> Journal of the American College of Cardiology. 65 (7), 684-697 (2015).</li><li>Aggarwal, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Persistent+diastolic+dysfunction+in+chronically+ischemic+hearts+following+coronary+artery+bypass+graft.">Persistent diastolic dysfunction in chronically ischemic hearts following coronary artery bypass graft.</a> The Journal of Thoracic and Cardiovascular Surgery. 165 (6), e269-e279 (2023).</li><li>Olsen, F. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prognostic+Value+and+Interplay+Between+Myocardial+Tissue+Velocities+in+Patients+Undergoing+Coronary+Artery+Bypass+Grafting.">Prognostic Value and Interplay Between Myocardial Tissue Velocities in Patients Undergoing Coronary Artery Bypass Grafting.</a> The American Journal of Cardiology. 144, 37-45 (2021).</li><li>Virani, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heart+Disease+and+Stroke+Statistics-2021+Update:+A+Report+From+the+American+Heart+Association.">Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association.</a> Circulation. 143 (8), e254-e743 (2021).</li><li>Hocum Stone, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surgical+Swine+Model+of+Chronic+Cardiac+Ischemia+Treated+by+Off-Pump+Coronary+Artery+Bypass+Graft+Surgery.">Surgical Swine Model of Chronic Cardiac Ischemia Treated by Off-Pump Coronary Artery Bypass Graft Surgery.</a> Journal of Visualized Experiments:JoVE. (133), e57229 (2018).</li><li>White, F. C., Carroll, S. M., Magnet, A., Bloor, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coronary+collateral+development+in+swine+after+coronary+artery+occlusion.">Coronary collateral development in swine after coronary artery occlusion.</a> Circulation Research. 71 (6), 1490-1500 (1992).</li><li>Righetti, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interventricular+septal+motion+and+left+ventricular+function+after+coronary+bypass+surgery:+evaluation+with+echocardiography+and+radionuclide+angiography.">Interventricular septal motion and left ventricular function after coronary bypass surgery: evaluation with echocardiography and radionuclide angiography.</a> The American Journal of Cardiology. 39 (3), 372-377 (1977).</li><li>Hocum Stone, L. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recovery+of+hibernating+myocardium+using+stem+cell+patch+with+coronary+bypass+surgery.">Recovery of hibernating myocardium using stem cell patch with coronary bypass surgery.</a> The Journal of Thoracic and Cardiovascular Surgery. 62 (1), e3-e16 (2021).</li><li>Puigserver, P., Spiegelman, B. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peroxisome+proliferator-activated+receptor-gamma+coactivator+1+alpha+(PGC-1+alpha):+transcriptional+coactivator+and+metabolic+regulator.">Peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1 alpha): transcriptional coactivator and metabolic regulator.</a> Endocrine Reviews. 24 (1), 78-90 (2003).</li><li>Henning, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiovascular+Exosomes+and+MicroRNAs+in+Cardiovascular+Physiology+and+Pathophysiology.">Cardiovascular Exosomes and MicroRNAs in Cardiovascular Physiology and Pathophysiology.</a> Journal of Cardiovascular Translational Research. 14 (2), 195-212 (2021).</li><li>Chen, Y., Liu, Y., Dorn, G. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=2nd.+Mitochondrial+fusion+is+essential+for+organelle+function+and+cardiac+homeostasis.">2nd. Mitochondrial fusion is essential for organelle function and cardiac homeostasis.</a> Circulation Research. 109 (12), 1327-1331 (2011).</li><li>Pittenger, M. F., Martin, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mesenchymal+stem+cells+and+their+potential+as+cardiac+therapeutics.">Mesenchymal stem cells and their potential as cardiac therapeutics.</a> Circulation Research. 95 (1), 9-20 (2004).</li><li>Campos-Silva, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+sensitivity+detection+of+extracellular+vesicles+immune-captured+from+urine+by+conventional+flow+cytometry.">High sensitivity detection of extracellular vesicles immune-captured from urine by conventional flow cytometry.</a> Scientific Reports. 9 (1), 2042 (2019).</li><li>Hocum Stone, L. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Magnetic+resonance+imaging+assessment+of+cardiac+function+in+a+swine+model+of+hibernating+myocardium+3+months+following+bypass+surgery.">Magnetic resonance imaging assessment of cardiac function in a swine model of hibernating myocardium 3 months following bypass surgery.</a> The Journal of Thoracic and Cardiovascular Surgery. 153 (3), 582-590 (2017).</li><li>Stone, L. L. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+Respiratory+Capacity+is+Restored+in+Hibernating+Cardiomyocytes+Following+Co-Culture+with+Mesenchymal+Stem+Cells.">Mitochondrial Respiratory Capacity is Restored in Hibernating Cardiomyocytes Following Co-Culture with Mesenchymal Stem Cells.</a> Cell Medicine. 11, 2155179019834938 (2019).</li><li>Lamy, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Skeletonized+vs+Pedicled+Internal+Mammary+Artery+Graft+Harvesting+in+Coronary+Artery+Bypass+Surgery:+A+Post+Hoc+Analysis+From+the+COMPASS+Trial.">Skeletonized vs Pedicled Internal Mammary Artery Graft Harvesting in Coronary Artery Bypass Surgery: A Post Hoc Analysis From the COMPASS Trial.</a> JAMA Cardiology. 6 (9), 1042-1049 (2021).</li><li>Shim, J. K., Choi, Y. S., Yoo, K. J., Kwak, Y. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbon+dioxide+embolism+induced+right+coronary+artery+ischaemia+during+off-pump+obtuse+marginalis+artery+grafting.">Carbon dioxide embolism induced right coronary artery ischaemia during off-pump obtuse marginalis artery grafting.</a> European Journal of Cardio-Thoracic Surgery. 36 (3), 598-599 (2009).</li><li>Aklog, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Future+technology+for+off-pump+coronary+artery+bypass+(OPCAB).">Future technology for off-pump coronary artery bypass (OPCAB).</a> Seminars in Thoracic and Cardiovascular Surgery. 15 (1), 92-102 (2003).</li><li>Hou, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radiolabeled+cell+distribution+after+intramyocardial,+intracoronary,+and+interstitial+retrograde+coronary+venous+delivery:+implications+for+current+clinical+trials.">Radiolabeled cell distribution after intramyocardial, intracoronary, and interstitial retrograde coronary venous delivery: implications for current clinical trials.</a> Circulation. 112 (9 Suppl), I150-I156 (2005).</li><li>Gallet, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exosomes+secreted+by+cardiosphere-derived+cells+reduce+scarring,+attenuate+adverse+remodelling,+and+improve+function+in+acute+and+chronic+porcine+myocardial+infarction.">Exosomes secreted by cardiosphere-derived cells reduce scarring, attenuate adverse remodelling, and improve function in acute and chronic porcine myocardial infarction.</a> European Heart Journal. 38 (3), 201-211 (2017).</li></ol>

This study presents the first porcine model of chronically ischemic myocardium, in which it was shown that treatment with an MSC-derived exosome laden collagen patch during surgical revascularization recovers diastolic and systolic function upon inotropic stimulation potentially by targeting mitochondrial recovery. Previously, it was demonstrated that in a large animal model of HIB the diastolic and systolic function, as measured by cardiac MRI, remains impaired and only slightly improves with revascularization without c...

Globally, severe CAD affects over a hundred million patients, and although the mortality rate has decreased, it remains one of the leading causes of death1,2. CAD has a wide clinical spectrum from myocardial infarction (MI) to ischemia with preserved viability. Most pre-clinical research focuses on MI, characterized by the presence of infarcted tissue as it is possible to study in small and large animal models. However, that model does not address patients with preserved viability and amenable to revascularization. Most patients undergoing CABG have decreased blood supply and limited function while maintaining variability in contractile reserve and viability3. Without treatment, these patients can progress to advanced heart failure and sudden death, especially during increased workload4. Among these patients, coronary artery bypass graft (CABG) is an effective therapy but may not result in complete functional recovery5. Importantly, diastolic dysfunction, which is a marker for worse clinical outcomes, fails to recover after revascularization suggesting the need for novel adjuvant therapies during CABG6,7. Currently, there are no clinically available adjuvant interventions used with CABG to restore cardiomyocytes to full functional capacity. This is a major therapeutic gap given that many patients progress to advanced heart failure despite appropriate revascularization8.
An innovative porcine model of chronic myocardial ischemia that is amenable to CABG, to mimic clinical CAD experience was created9. Swine provide a good model of heart disease over other large animals as they do not have epicardial bridging collaterals so stenosis of the LAD alone results in regional ischemia10. In this study, 16-week-old female Yorkshire-Landrace pigs were used. In this model, the LAD was revascularized with off-pump CABG using the left internal mammary artery (LIMA) graft (Supplementary Table 1). Percutaneous coronary intervention (PCI) is not possible to open the stenosis as the constrictor is a rigid device. Cardiac magnetic resonance imaging (MRI) is used to assess global and regional function, coronary anatomy, and tissue viability. Cardiac MRI analysis showed diastolic function, characterized by peak filling rate (PFR) remains impaired despite CABG6. The mechanism of diastolic dysfunction likely relates to impaired mitochondrial bioenergetics and collagen formation in HIB that persist following CABG11.
Mesenchymal stem cells (MSC) provide therapeutic signaling through exosomes to improve myocardial recovery when applied during CABG. In this swine model and parallel in vitro studies, it was shown that placement of an epicardial MSC vicryl patch during CABG recovers contractile function with increase in key mitochondrial proteins namely PGC-1&#945;12, an important regulator of mitochondrial energy metabolism13. The in vitro model allowed us to investigate the signaling mechanism of MSCs on impaired mitochondrial function. Exosomes are secreted stable microvesicles (50-150 nm) that contain protein or nucleic acids including microRNA (miRNA)14. Recent in vitro data suggest that MSC-derived exosomes are an important signaling mechanism necessary for recovery of mitochondrial respiration.
Stem cell derived exosomes are promising adjunctive therapeutics as they are readily accessible, can be commercially produced, and lack ethical conflicts. In consideration of clinical translation, a collagen patch embedded with MSC-derived exosomes was created that can be surgically sutured to the hibernating region of myocardium. It was demonstrated that there is sustained delivery of exosomes using this patch and it provides a cell-free regenerative therapy with paracrine signaling mechanism that targets mitochondrial recovery and enhance mitochondrial biogenesis15. This procedure provides the pre-clinical model to study the impact of MSC-derived therapies to improve cardiac function by means of enhancing mitochondrial function and reducing inflammation at the time of revascularization and reverse the myocyte adaptations to chronic ischemia.
In this study, a surgical method of off-pump CABG using LIMA to LAD anastomosis to bypass the area of proximal LAD stenosis mimicking the standard treatment for patients with CAD is shown. As an adjunctive therapy with CABG, the surgical application of MSC-derived exosome embedded collagen patch on the ischemic region of the myocardium was demonstrated. This surgical model can be used to study the physiologic responses to the paracrine effect seen with use of an exosome patch as well as the molecular mechanisms of recovery.

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	<tbody>
		<tr>
			<td>5 Ethibond</td>
			<td>Ethicon</td>
			<td>MG46G</td>
			<td>Suture</td>
		</tr>
		<tr>
			<td># 40 clipper blade</td>
			<td>Oster</td>
			<td>078919-016-701</td>
			<td>Remove hair from surgery sites</td>
		</tr>
		<tr>
			<td>0 Vicryl</td>
			<td>Ethicon</td>
			<td>J208H</td>
			<td>Suture</td>
		</tr>
		<tr>
			<td>1 mL Syringe</td>
			<td>Medtronic/Covidien</td>
			<td>1188100777</td>
			<td>Administer injectable agents</td>
		</tr>
		<tr>
			<td>1&#34; medical tape</td>
			<td>Medline</td>
			<td>MMM15271Z</td>
			<td>Secure wound dressing and IV catheters</td>
		</tr>
		<tr>
			<td>1000mL 0.9% Sodium chloride</td>
			<td>Baxter</td>
			<td>2B1324X</td>
			<td>IV replacement fluid</td>
		</tr>
		<tr>
			<td>12 mL Syringe</td>
			<td>Medtronic/Covidien</td>
			<td>8881512878</td>
			<td>Administer injectable agents</td>
		</tr>
		<tr>
			<td>18 ga needles</td>
			<td>BD</td>
			<td>305185</td>
			<td>Administration of injectable agents</td>
		</tr>
		<tr>
			<td>20 ga needles</td>
			<td>BD</td>
			<td>305175</td>
			<td>Administration of injectable agents</td>
		</tr>
		<tr>
			<td>20 mL Syringe</td>
			<td>Medtronic/Covidien</td>
			<td>8881520657</td>
			<td>Administer injectable agents</td>
		</tr>
		<tr>
			<td>2-0 Vicryl</td>
			<td>Ethicon</td>
			<td>J317H</td>
			<td>Suture</td>
		</tr>
		<tr>
			<td>250 mL 0.9% saline</td>
			<td>Baxter</td>
			<td>&#160;UE1322D</td>
			<td>Replacement IV Fluid</td>
		</tr>
		<tr>
			<td>3 mL Syinge</td>
			<td>Medtronic/Covidien</td>
			<td>1180300555</td>
			<td>Administer injectable agents</td>
		</tr>
		<tr>
			<td>3-0 Vicryl</td>
			<td>Ethicon</td>
			<td>VCP824G</td>
			<td>Suture</td>
		</tr>
		<tr>
			<td>36&#8221; Pressure monitoring tubing</td>
			<td>Smith&#8217;s Medical</td>
			<td>MX563</td>
			<td>Connect art. Line&#160; to transducer</td>
		</tr>
		<tr>
			<td>4.0 mm ID endotracheal tube</td>
			<td>Medline</td>
			<td>DYND43040</td>
			<td>Establish airway for Hibernation</td>
		</tr>
		<tr>
			<td>4-0 Tevdek II Strands</td>
			<td>Deknatel</td>
			<td>7-922</td>
			<td>Suture to secure constrictor around LAD</td>
		</tr>
		<tr>
			<td>48&#8221; Pressure monitoring tubing</td>
			<td>Smith&#8217;s Medical</td>
			<td>MX564</td>
			<td>Connect art. Line&#160; to transducer</td>
		</tr>
		<tr>
			<td>500mL 0.9% Sodium chloride</td>
			<td>Baxter</td>
			<td>2B1323Q</td>
			<td>Drug delivery, Provide mist for Blower Mister</td>
		</tr>
		<tr>
			<td>6&#160; mL Syringe</td>
			<td>Medtronic/Covidien</td>
			<td>1180600777</td>
			<td>Administer injectable agents</td>
		</tr>
		<tr>
			<td>6.0 mm ID endotracheal tube</td>
			<td>Mallinckrodt</td>
			<td>86049</td>
			<td>Establish airway for Revasc,MRI and Termination</td>
		</tr>
		<tr>
			<td>6.5 mm ID endotracheal tube</td>
			<td>Medline</td>
			<td>DYND43065</td>
			<td>Establish airway for Revasc,MRI and Termination</td>
		</tr>
		<tr>
			<td>6&#8221; pressure tubing line</td>
			<td>Smith&#8217;s Medical</td>
			<td>MX560</td>
			<td>Collect bone marrow</td>
		</tr>
		<tr>
			<td>60 mL Syringe</td>
			<td>Medtronic/Covidien</td>
			<td>8881560125</td>
			<td>Administer injectable agents</td>
		</tr>
		<tr>
			<td>7.0 mm ID endotracheal tube</td>
			<td>Medline</td>
			<td>DYND43070</td>
			<td>Establish airway for Revasc,MRI and Termination</td>
		</tr>
		<tr>
			<td>7-0 Prolene</td>
			<td>Ethicon</td>
			<td>M8702</td>
			<td>Suture</td>
		</tr>
		<tr>
			<td>Advanced DMEM (1X)</td>
			<td>ThermoFisher Scientific</td>
			<td>12491023</td>
			<td></td>
		</tr>
		<tr>
			<td>Alcohol Prep pads</td>
			<td>MedSource</td>
			<td>MS-17402</td>
			<td>Skin disinfectant</td>
		</tr>
		<tr>
			<td>Amicon Ultra-15 Centrifugal Filter Unit</td>
			<td>Millipore Sigma</td>
			<td>UFC910024</td>
			<td></td>
		</tr>
		<tr>
			<td>Anesthesia Machine</td>
			<td>Drager</td>
			<td>Fabious Trio</td>
			<td>maintains general anesthesia</td>
		</tr>
		<tr>
			<td>Anesthesia Machine + ventilator</td>
			<td>DRE Drager- Fabius Tiro</td>
			<td>DRE0603FT</td>
			<td>Deliver Oxygen and inhalant to patient</td>
		</tr>
		<tr>
			<td>Anesthesia Monitor</td>
			<td>Phillips&#160; Intellivue</td>
			<td>MP70</td>
			<td>Multiparameter for patient safety</td>
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		<tr>
			<td>Arterial Line Kit</td>
			<td>Arrow</td>
			<td>ASK-04510-HF</td>
			<td>Femoral catheter for blood pressure monitoring</td>
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			<td>Artificial Tears</td>
			<td>Rugby</td>
			<td>0536-1086-91</td>
			<td>Lubricate eyes to prevent corneal drying</td>
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			<td>Bair Hugger</td>
			<td>3M</td>
			<td>Model 505</td>
			<td>Patient Warming system</td>
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		<tr>
			<td>Basic pack</td>
			<td>Medline</td>
			<td>DYNJP1000</td>
			<td>Sterile drapes and table cover</td>
		</tr>
		<tr>
			<td>Blood Collection Tubes- green top</td>
			<td>Fisher Scientific</td>
			<td>02-689-7</td>
			<td>Collect microsphere blood samples</td>
		</tr>
		<tr>
			<td>Blower Mister Kit</td>
			<td>Medtronic/Covidien</td>
			<td>22120</td>
			<td>Clears surgical field for vessel anastomosis</td>
		</tr>
		<tr>
			<td>BODIPY TR Ceramide</td>
			<td>ThermoFisher Scientific</td>
			<td>D7540</td>
			<td></td>
		</tr>
		<tr>
			<td>Bone marrow needle- 25mm 15 ga IO needle</td>
			<td>Vidacare</td>
			<td>9001-VC-005</td>
			<td>Collect bone marrow</td>
		</tr>
		<tr>
			<td>Bone Wax</td>
			<td>Medline</td>
			<td>ETHW31G</td>
			<td>Hemostasis of cut bone</td>
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		<tr>
			<td>Bovie Cautery hand piece</td>
			<td>Covidien</td>
			<td>E2516</td>
			<td>Hemostasis</td>
		</tr>
		<tr>
			<td>Bupivicaine</td>
			<td>Pfizer</td>
			<td>00409-1161-01</td>
			<td>Local Anesthetic</td>
		</tr>
		<tr>
			<td>Buprenorphine 0.3 mg/mL</td>
			<td>Sigma Aldrich</td>
			<td>B9275</td>
			<td>Pre operative Analgesic for survivial procedures</td>
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		<tr>
			<td>Cell Scrapers</td>
			<td>Corning</td>
			<td>353085</td>
			<td></td>
		</tr>
		<tr>
			<td>Cephazolin 1 gr</td>
			<td>Pfizer</td>
			<td>00409-0805-01</td>
			<td>Antibiotic</td>
		</tr>
		<tr>
			<td>Chest Tube</td>
			<td>Covidien</td>
			<td>8888561043</td>
			<td>Evacuates air from chest cavity</td>
		</tr>
		<tr>
			<td>Cloroprep</td>
			<td>Becton Dickenson</td>
			<td>260815</td>
			<td>Surgical skin prep</td>
		</tr>
		<tr>
			<td>Corning bottle-top vacuum Filter System (500mL)</td>
			<td>Millipore Sigma</td>
			<td>430758</td>
			<td></td>
		</tr>
		<tr>
			<td>CPT tube</td>
			<td>BD</td>
			<td>362753</td>
			<td>MSC isolation from bone marrow</td>
		</tr>
		<tr>
			<td>Delrin Constrictor</td>
			<td>U of MN</td>
			<td>Custom made</td>
			<td>Creates stenosis of LAD</td>
		</tr>
		<tr>
			<td>Dermabond</td>
			<td>Ethicon</td>
			<td>DNX12</td>
			<td>Skin adhesive</td>
		</tr>
		<tr>
			<td>DMEM (1X) Dulbecco&#39;s Modified Eagle Medium, HEPES</td>
			<td>ThermoFisher Scientific</td>
			<td>12430062</td>
			<td></td>
		</tr>
		<tr>
			<td>Dobutamine 12.5 mg/mL</td>
			<td>Pfizer</td>
			<td>00409-2344-01</td>
			<td>Increases blood pressure and heart rate during the second microsphere blood collection</td>
		</tr>
		<tr>
			<td>ECG Pads</td>
			<td>DRE</td>
			<td>1496</td>
			<td>Monitor heart rhythm</td>
		</tr>
		<tr>
			<td>Exosome-Depleted FBS</td>
			<td>ThermoFisher Scientific</td>
			<td>A2720801</td>
			<td></td>
		</tr>
		<tr>
			<td>Falcon Disposable Polystyrene Serological Pipets, Sterile, 10mL</td>
			<td>Fisher Scientific</td>
			<td>13-675-20</td>
			<td></td>
		</tr>
		<tr>
			<td>Femoral and carotid introducer</td>
			<td>Cordis- J&#38;J</td>
			<td>504606P</td>
			<td>femoral and carotis cannulas</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum, Heat Inactivated, Gibco FBS</td>
			<td>ThermoFisher Scientific</td>
			<td>16140089</td>
			<td></td>
		</tr>
		<tr>
			<td>Flo-thru 1.0</td>
			<td>Baxter</td>
			<td>FT-12100</td>
			<td>used to anastomos LIMA to L</td>
		</tr>
		<tr>
			<td>Flo-thru 1.25</td>
			<td>Baxter</td>
			<td>FT-12125</td>
			<td>FT-12125</td>
		</tr>
		<tr>
			<td>Flo-thru 1.5</td>
			<td>Baxter</td>
			<td>FT-12150</td>
			<td>FT-12150</td>
		</tr>
		<tr>
			<td>Flo-thru 2.0</td>
			<td>Baxter</td>
			<td>FT-12200</td>
			<td>FT-12200</td>
		</tr>
		<tr>
			<td>GlutaMAX Supplement</td>
			<td>ThermoFisher Scientific</td>
			<td>35050061</td>
			<td></td>
		</tr>
		<tr>
			<td>Hair Clipper</td>
			<td>Oster</td>
			<td>078566-011-002</td>
			<td>Remove hair from surgery sites</td>
		</tr>
		<tr>
			<td>Helistat collagen sponge</td>
			<td>McKesson</td>
			<td>570973 1690ZZ</td>
			<td>Sponge for embedding exosomes</td>
		</tr>
		<tr>
			<td>Heparin</td>
			<td>Pfizer</td>
			<td>&#160;0409-2720-03</td>
			<td>anticoaggulant</td>
		</tr>
		<tr>
			<td>Histology Jars</td>
			<td>Fisher Scientific</td>
			<td>316-154</td>
			<td>Formalin for tissue samples</td>
		</tr>
		<tr>
			<td>HyClone Characterized Fetal Bovine Serum (FBS)</td>
			<td>Cytiva</td>
			<td>SH30071.03</td>
			<td></td>
		</tr>
		<tr>
			<td>Hypafix</td>
			<td>BSN Medical</td>
			<td>4210</td>
			<td>Secure wound dressing and IV catheters</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Sigma Aldrich</td>
			<td>CDS019936</td>
			<td>General Anesthestic- Inhalant</td>
		</tr>
		<tr>
			<td>IV Tubing for Blower Mister</td>
			<td>Carefusion</td>
			<td>42493E</td>
			<td>Adapts to IV Fluids for Blower/Mister</td>
		</tr>
		<tr>
			<td>Jelco 18 ga IV catheter</td>
			<td>Smiths medical</td>
			<td>4054</td>
			<td>IV access in Revasc, MRI and Term</td>
		</tr>
		<tr>
			<td>Lidocaine 2%</td>
			<td>Pfizer</td>
			<td>00409-4277-01</td>
			<td>Local Anesthetic/ antiarrthymic</td>
		</tr>
		<tr>
			<td>Ligaclips</td>
			<td>Ethicon</td>
			<td>MSC20</td>
			<td>Surgical Staples for LIMA takedown</td>
		</tr>
		<tr>
			<td>Long blade for laryngoscope</td>
			<td>DRE</td>
			<td>12521</td>
			<td>Allows for visualization of trachea for intubation</td>
		</tr>
		<tr>
			<td>Meloxicam 5 mg/mL</td>
			<td>Boehringer Ingelheim</td>
			<td>141-219</td>
			<td>Post operative Analgesic</td>
		</tr>
		<tr>
			<td>Microsphere pump</td>
			<td></td>
			<td></td>
			<td>Collect blood samples from femoral introducer</td>
		</tr>
		<tr>
			<td>Monopolar Cautery</td>
			<td>Covidien</td>
			<td>Valleylab&#8482; FT10</td>
			<td>Hemostasis</td>
		</tr>
		<tr>
			<td>Nanosight NS 300</td>
			<td>Malvern Panalytical</td>
			<td>MAN0541-03-EN</td>
			<td></td>
		</tr>
		<tr>
			<td>NTA 3.1.54 software</td>
			<td>Malvern Panalytical</td>
			<td>MAN0520-01-EN-00</td>
			<td></td>
		</tr>
		<tr>
			<td>OPVAC Synergy II</td>
			<td>Terumo Cardiovascular System</td>
			<td>401-230</td>
			<td>Heart positioner and Stabilizer</td>
		</tr>
		<tr>
			<td>Oxygen Tank E cylinder</td>
			<td>various</td>
			<td>various</td>
			<td>Used for Blower Mister if anesthesia machine doesn&#39;t have auxiliary flow meter</td>
		</tr>
		<tr>
			<td>PBS, pH 7.2</td>
			<td>ThermoFisher Scientific</td>
			<td>20012050</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin-Neomycin (PSN) Antibiotic Mixture</td>
			<td>ThermoFisher Scientific</td>
			<td>15640055</td>
			<td></td>
		</tr>
		<tr>
			<td>Pigtail 145 catheter 6 French</td>
			<td>Boston Scientific</td>
			<td>08641-41</td>
			<td>Measure LV pressures</td>
		</tr>
		<tr>
			<td>Pressure Transducer</td>
			<td>various</td>
			<td>Must adapt to anesthesia monitor</td>
			<td>Monitor direct arterial pressures</td>
		</tr>
		<tr>
			<td>Propofol</td>
			<td>Diprivan</td>
			<td>269-29</td>
			<td>Induction agent</td>
		</tr>
		<tr>
			<td>Roncuronium</td>
			<td>Mylan</td>
			<td>67457-228-05</td>
			<td>Neuromuscular blocking agent</td>
		</tr>
		<tr>
			<td>SR Buprenorphine 10 mg/mL</td>
			<td>Abbott Labs</td>
			<td>NADA 141-434</td>
			<td>Post operative Analgesic</td>
		</tr>
		<tr>
			<td>Sterile Saline 20 mL</td>
			<td>Fisher Scientific</td>
			<td>20T700220</td>
			<td>Flush for IV catheters</td>
		</tr>
		<tr>
			<td>Sternal Saw/ Necropsy Saw</td>
			<td>Thermo Fisher</td>
			<td>812822</td>
			<td>Used to open chest cavity</td>
		</tr>
		<tr>
			<td>Stop Cocks</td>
			<td>Smith Medical</td>
			<td>MX5311L</td>
			<td>2 to connect to pig tail</td>
		</tr>
		<tr>
			<td>Succinylcholine 20 mg/mL</td>
			<td>Pfizer</td>
			<td>00409-6629-02</td>
			<td>Neuromuscular blocking agent</td>
		</tr>
		<tr>
			<td>Suction&#160; tubing</td>
			<td>Medline</td>
			<td>DYND50223</td>
			<td></td>
		</tr>
		<tr>
			<td>Suction Container</td>
			<td>Medline</td>
			<td>DYNDCL03000</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgery pack with chest retractor</td>
			<td>various</td>
			<td>See pack list</td>
			<td>Femoral cut down and median sternotomy</td>
		</tr>
		<tr>
			<td>Surgical Instruments</td>
			<td>various</td>
			<td>See pack list</td>
			<td>Femoral and carotid cutdowns and sternotomy</td>
		</tr>
		<tr>
			<td>Surgical Spring Clip</td>
			<td>Applied Medical</td>
			<td>A1801</td>
			<td>Clamp end of LIMA after takedown</td>
		</tr>
		<tr>
			<td>Syringe pump</td>
			<td>Harvard</td>
			<td></td>
			<td>Delivers IV Dobutamine infusion</td>
		</tr>
		<tr>
			<td>SYTO RNASelect Green Fluorescent cell Stain - 5 mM Solution in DMSO</td>
			<td>Millipore Sigma</td>
			<td>S32703</td>
			<td></td>
		</tr>
		<tr>
			<td>Telazol 100 mg/mL</td>
			<td>Fort Dodge</td>
			<td>01L60030</td>
			<td>Pre operative Sedative</td>
		</tr>
		<tr>
			<td>Telpha pad</td>
			<td>Covidien</td>
			<td>2132</td>
			<td>Sterile wound dressing</td>
		</tr>
		<tr>
			<td>Timer</td>
			<td></td>
			<td></td>
			<td>Time collection of blood samples</td>
		</tr>
		<tr>
			<td>Total Exosome Isolation Reagent (from cell culture media)</td>
			<td>ThermoFisher Scientific</td>
			<td>4478359</td>
			<td></td>
		</tr>
		<tr>
			<td>TPP Tissue Culture Flask, T75, Filter Cap w/ 0.22uM PTFE</td>
			<td>ThermoFisher Scientific</td>
			<td>TP90076</td>
			<td></td>
		</tr>
		<tr>
			<td>Triple Antibiotic Ointment</td>
			<td>Johnson &#38; Johnson</td>
			<td>23734</td>
			<td>Topical over wound</td>
		</tr>
		<tr>
			<td>Vicryl mesh</td>
			<td>Ethicon</td>
			<td>VKML</td>
			<td>Patch for epicardial cell application</td>
		</tr>
		<tr>
			<td>Vortex</td>
			<td></td>
			<td></td>
			<td>Mix microspheres</td>
		</tr>
		<tr>
			<td>Xylazine 100 mg/mL</td>
			<td>Vedco</td>
			<td>468RX</td>
			<td>Pre operative Sedative/ analgesic</td>
		</tr>
	</tbody>
</table>

surgical porcine model of chronic myocardial ischemia treated by exosome-laden collagen patch and off-pump coronary artery bypass graft

Chronic myocardial ischemia resulting from progressive coronary artery stenosis leads to hibernating myocardium (HIB), defined as myocardium that adapts to reduced oxygen availability by reducing metabolic activity, thereby preventing irreversible cardiomyocyte injury and infarction. This is distinct from myocardial infarction, as HIB has the potential for recovery with revascularization. Patients with significant coronary artery disease (CAD) experience chronic ischemia, which puts them at risk for heart failure and sudden death. The standard surgical intervention for severe CAD is coronary artery bypass graft surgery (CABG), but it has been shown to be an imperfect therapy, yet no adjunctive therapies exist to recover myocytes adapted to chronic ischemia. To address this gap, a surgical model of HIB using porcine that is amenable to CABG and mimics the clinical scenario was used. The model involves two surgeries. The first operation involves implanting a 1.5 mm rigid constrictor on the left anterior descending (LAD) artery. As the animal grows, the constrictor gradually causes significant stenosis resulting in reduced regional systolic function. Once the stenosis reaches 80%, the myocardial flow and function are impaired, creating HIB. An off-pump CABG is then performed with the left internal mammary artery (LIMA) to revascularize the ischemic region. The animal recovers for one month to allow for optimal myocardial improvement prior to sacrifice. This allows for physiologic and tissue studies of different treatment groups. This animal model demonstrates that cardiac function remains impaired despite CABG, suggesting the need for novel adjunctive interventions. In this study, a collagen patch embedded with mesenchymal stem cell (MSC)-derived exosomes was developed, which can be surgically applied to the epicardial surface distal to LIMA anastomosis. The material conforms to the epicardium, is absorbable, and provides the scaffold for the sustained release of signaling factors. This regenerative therapy can stimulate myocardial recovery that does not respond to revascularization alone. This model translates to the clinical arena by providing means of physiological and mechanistic explorations regarding recovery in HIB.

Author Spotlight: Enhancing Coronary Artery Revascularization

Surgical Porcine Model of Chronic Myocardial Ischemia Treated by Exosome-laden Collagen Patch and Off-pump Coronary Artery Bypass Graft

The overall goal of this surgical procedure is to create a surgical model of coronary artery revascularization using LIMA to LAD bypass, and the use of exosome-laden collagen patch as an adjunct to demonstrate physiological improvement in cardiac function. Our in-vivo model is a single-vessel model that does not include any comorbidities, which is not representative of the typical clinical situation for patients undergoing treatment for multi-vessel disease. However, despite this limitation, our model has consistently produced reliable results and has maintained low mortality rates.We developed a clinically relevant adjuvant therapy to be used during CABG and aim to understand the cellular mechanisms driving the myocardial functional improvement in chronic myocardial ischemia. Complete recovery of ischemic tissue appears to hinge on restoration of mitochondrial capabilities and reduced inflammation;representing a novel area of study.

Following revascularization, coronary angiography is performed to assess for LAD stenosis (greater than 80%) and patency of the LIMA-LAD graft (Figure 1). Four weeks following the revascularization surgery and placement of the exosome-laden collagen patch, cardiac MRI is performed to assess for systolic and diastolic function of the heart at rest and under stress using low-dose dobutamine infusion at 5&#181;g/kg/min. Systolic function is analyzed by measuring wall thickness percentage (wall ...

Watch this Scientific Journal Video about Surgical Porcine Model of Chronic Myocardial Ischemia Treated by Exosome-laden Collagen Patch and Off-pump Coronary Artery Bypass Graft at JoVE.com

This study presents a surgical porcine model of chronic myocardial ischemia due to progressive coronary artery stenosis, resulting in impaired cardiac function without infarction. Following ischemia, animals undergo off-pump coronary artery bypass graft with epicardial placement of stem cells-derived exosomes-laden collagen patch. This adjunctive therapy improves myocardial function and recovery.

Chronic myocardial ischemia resulting from progressive coronary artery stenosis leads to hibernating myocardium (HIB), defined as myocardium that adapts ...

surgical-porcine-model-chronic-myocardial-ischemia-treated-exosome

Research

JoVE Journal

Medicine

437 ビュー.  University of Minnesota. この外科的処置の全体的な目標は、冠動脈血行再建術の外科的モデルを作成することです LIMAからLADバイパス、およびエクソソームを含むコラーゲンパッチを補助として使用して、心機能の生理学的改善を実証します。私たちの生体内モデルは、併存疾患を含まない単一血管モデルであり、多血管疾患の治療を受けている患者の典型的な臨床状況を代表するものではあり...

ビデオ: 著者スポットライト:冠動脈血行再建術の強化

This study presents a surgical porcine model of chronic myocardial ischemia due to progressive coronary artery stenosis, resulting in impaired cardiac function without infarction. Following ischemia, animals undergo off-pump coronary artery bypass graft with epicardial placement of stem cells-derived exosomes-laden collagen patch. This adjunctive therapy improves myocardial function and...

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signal acquisition, score interpretation, and economics of a non-invasive point-of-care test for coronary artery disease

Author Spotlight: Enhancing Coronary Artery Disease Diagnosis with Non-Invasive Point-of-Care Testing

The methodology to acquire the physiological signal for a Coronary Artery Disease (CAD) test is presented. A method is proposed to interpret the CAD score concerning test positivity and negativity, including the granularities of each. The economics of the test are discussed in the context of the current standard of...

Non-Invasive Point-of-Care Test for Coronary Artery Disease Assessment 

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semi-automatic graphical tool for measuring coronary artery spatially weighted calcium score from gated cardiac computed tomography images

Author Spotlight: Advancing Cardiovascular Imaging - Introducing the Spatially Weighted Calcium Score for Early Disease Detection 

This video demonstrates the use of a novel graphical tool for measuring the spatially weighted calcium score (SWCS), an alternative to the Agatston score, for quantifying coronary artery calcification. The graphical tool computes SWCS based on image data from gated cardiac computed tomography and user-defined paths of the coronary arteries.

Improving Coronary Artery Calcification Assessment with the SWCS Tool

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coronary angiography during ex-situ heart perfusion in a porcine model

Author Spotlight: Innovative Technique for Coronary Angiography in Marginal Donors

Screening for coronary artery disease could increase the procurement of donor hearts with extended criteria. A protocol for performing reproducible coronary angiography during ex-situ heart perfusion is described herein in a porcine...

Coronary Artery Assessment During Ex-Situ Heart Perfusion

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measuring coronary artery spatially weighted calcium score for quantifying coronary artery calcification

Measuring Coronary Artery Spatially Weighted Calcium Score for Quantifying Coronary Artery Calcification  

preclinical evaluation of coronary artery stents

Preclinical Evaluation of Coronary Artery Stents

New coronary artery stent designs and materials must be tested before clinical use in relevant preclinical models. Here we describe an atherosclerotic rabbit aorta model and a pig coronary artery model for stent research with in vivo and histological analyses.

a modified model preparation for middle cerebral artery occlusion reperfusion

Author Spotlight: A Novel Approach to Cerebral Ischemia Modeling &amp;#8211; Enhancing Reperfusion and Simplifying Procedure

This protocol describes the process of preparing for middle cerebral artery occlusion reperfusion via the common carotid...

Modified MCAO/R Model with Preserved ECA for Enhanced Reperfusion and Stability

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direct re-implantation of left coronary artery into the aorta in adults with anomalous origin of left coronary artery from the pulmonary artery (alcapa)

Direct Re-implantation of Left Coronary Artery into the Aorta in Adults with Anomalous Origin of Left Coronary Artery from the Pulmonary Artery ALCAPA

Surgical correction of ALCAPA is highly recommended, regardless of age or the degree of intercoronary collateralization. This protocol presents a technique for the direct re-implantation of adult-type ALCAPA into the aorta to re-establish the dual-coronary perfusion. Whenever feasible, direct re-implantation is preferred to other surgical correction...

Direct Re-implantation of Left Coronary Artery into the Aorta in Adults with Anomalous Origin of Left Coronary Artery from the Pulmonary Artery (ALCAPA)

intravascular ultrasound image-based finite element modeling approach for quantifying in vivo mechanical properties of human coronary artery 

Author Spotlight: In Vivo Quantification of Coronary Artery Properties Using Patient-Specific FEM Analysis

In vivo cine intravascular ultrasound images show the coronary cross-sectional movement corresponding to different pressure loading conditions. Based on a finite element model, an iterative scheme was employed to determine the patient-specific mechanical properties of coronary arteries in vivo by matching coronary motion from the computational model and medical images.

 IVUS-Based Computational Method to Quantify Coronary Mechanical Properties

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modified technique for coronary artery ligation in mice

Modified Technique for Coronary Artery Ligation in Mice

The surgical procedure used to induce experimental myocardial infarction in mice begins with left thoracotomy between the third and the fourth ribs in order to visualize the anterior surface of the heart and left lung. The left coronary artery is ligated, the chest is closed and the mouse is allowed to recover...

identifying coronary artery calcification on non-gated computed tomography scans

Identifying Coronary Artery Calcification on Non-gated Computed Tomography Scans

Here, we present a protocol to reliably and systematically identify coronary artery calcification (CAC) on non-gated computed tomography (CT) scans of the chest or abdomen. CAC provides an objective measure of coronary artery disease for both research and clinical...

left coronary artery ligation: a surgical murine model of myocardial infarction

Left Coronary Artery Ligation: A Surgical Murine Model of Myocardial Infarction

Presented here is a surgical procedure for permanent ligation of the left coronary artery in mice. This model can be used to investigate the pathophysiology and associated inflammatory response after myocardial infarction.

ultrasound based assessment of coronary artery flow and coronary flow reserve using the pressure overload model in mice

Ultrasound Based Assessment of Coronary Artery Flow and Coronary Flow Reserve Using the Pressure Overload Model in Mice

Coronary flow reserve (CFR) is useful for assessment of myocardial oxygen demand and evaluation of cardiovascular risk. This study establishes a step-by-step transthoracic Doppler echocardiographic (TTDE) method for longitudinal monitoring of the changes in CFR, as measured from coronary artery in mice, under the experimental pressure overload of aortic...

normothermic ex situ porcine heart perfusion and coronary angiography for artery assessment

Normothermic Ex Situ Porcine Heart Perfusion and Coronary Angiography for Artery Assessment

left anterior descending coronary artery ligation for cardiac monitoring in mice

Left Anterior Descending Coronary Artery Ligation for Cardiac Monitoring in Mice

use of a hanging weight system for coronary artery occlusion in mice

Use of a Hanging Weight System for Coronary Artery Occlusion in Mice

A murine model for myocardial ischemia and ischemic preconditioning is an important tool study cardioprotective mechanisms in vivo. Here, we report an easy applicable in situ model for cardiac IP using a hanging-weight system for coronary artery...

coronary artery ligation and intramyocardial injection in a murine model of infarction

Coronary Artery Ligation and Intramyocardial Injection in a Murine Model of Infarction

Numerous genetic manipulations and/or intramyocardial injections of genes, proteins, cells, and/or biomaterials are superimposed upon the dimension of time in studies of acute ischemia/ reperfusion injury and chronic remodeling in mice.  This video illustrates the microsurgical procedures for ischemia/reperfusion, permanent coronary artery ligation, and intramyocardial injection...

surgical swine model of chronic cardiac ischemia treated by off-pump coronary artery bypass graft surgery

Surgical Swine Model of Chronic Cardiac Ischemia Treated by Off-Pump Coronary Artery Bypass Graft Surgery

This protocol presents a surgical large animal model of chronic, single vessel ischemia that results in regional abnormalities but does not create infarct, known as hibernating myocardium. Following establishment of chronic ischemia, animals are treated with off-pump LIMA-LAD coronary artery bypass graft surgery to revascularize the ischemic...

murine myocardial infarction model using permanent ligation of left anterior descending coronary artery

Murine Myocardial Infarction Model using Permanent Ligation of Left Anterior Descending Coronary Artery

Herein we describe a surgical procedure showing how to achieve permanent ligation of the left-anterior descending coronary artery in mice. This model is of high relevance to investigate the pathophysiology of myocardial infarction and the concomitant biological...

transient middle cerebral artery occlusion model of stroke

Author Spotlight: Assessing Ischemic Stroke Damage Through Middle Cerebral Artery Occlusion Model 

This protocol describes the model of transient focal cerebral ischemia in mice through intraluminal occlusion of the middle cerebral artery. Additionally, examples of outcome assessment are shown using magnetic resonance imaging and behavioral...

A Model of Transient Cerebral Ischemia by Occlusion of Middle Cerebral Artery

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Off-Pump Coronary Artery Bypass Graft Surgery for Preparing a Porcine Model of Chronic Myocardial Ischemia

To begin, position the anesthetized and intubated animal on its back and cover it with sterile towels. Use monopolar electrocautery to make a 20 centimeter incision, extending from the sternal notch proximally down to the xiphoid process distally, and to incise layers of muscles, subcutaneous fat and connective tissue down to the sternum. Then carry out a medium sternotomy, employing an oscillating saw.For efficient visualization of the mediastinum, use a specialized chest retractor. Dissect adhesions using monopolar electrocautery or Metzenbaum scissors. Then expose LIMA by dissecting the parasternal muscle and fat.Next, start the dissection of the LIMA by elevating the left sternal border to ensure optimal visualization. Apply gentle traction to the adventitia and expose the arterial and venous branches of the LIMA. Employ blunt dissection using electrocautery tip to carefully separate it from the chest wall.Use hemo clips on the branches and cauterize the chest wall side of these branches. Then clip the distal end of the LIMA just before the point of bifurcation and divide the conduit. Secure the distal end with a freely tied 2-O silk suture.After preparing the proximal end for grafting, evaluate the flow quality manually by allowing the graft to bleed briefly. Now clamp the distal end of the LIMA conduit with an atraumatic bulldog clamp to prevent bleeding. Stabilize the left anterior descending, or LAD artery, using silicone retraction tape and a tissue stabilizer that's secured to the sternal retractor.Perform an arteriotomy in the LAD artery distal to the stenosis, using an 11 blade, and extend it with iris scissors. Position an appropriately sized coronary shunt in the LAD artery. Conduct the LIMA to LAD anastomosis using a 7-O running, non-absorbable suture in an off-pump bypass technique.Take a three millimeter exosome suspension and use a five milliliter syringe equipped with an 18 gauge needle to mix it. Then gradually pipette 1.5 milliliters of this suspension onto two absorbable collagen sponges, placed in a medium sized Petri dish. To target the hibernating region of the heart, place the exosome sponge upside down on the epicardium of the anterior septal region in the distribution of the LAD artery.Carefully arrange two sponges to fully cover the hibernating region. Use a polyglactin mesh on each collagen sponge to ensure proper coverage and sew the mesh onto the epicardium with fine 7-O interrupted sutures. Make a separate stab incision near the inferior aspect of the sternotomy incision and place the chest tube carefully on the anterior aspect of the heart.Approximate the sternum using non-absorbable sutures, employing a figure eight pattern. Close layers of muscle and skin using 2-O and 3-O absorbable sutures, respectively, following the standard procedure. After evacuating the chest cavity with a chest tube, seal the wound using a purse string suture.Once the wound is closed, remove the chest tube. At rest, the peak filling rate over end diastolic volume is compared among four animal groups. In low dose dobutamine infusion, the group with hibernating myocardium had a decrease in peak filling rate.The coronary artery bypass graft surgery group showed improvement, while the coronary artery bypass graft, plus mesenchymal stem cell group, saw a significant increase. MRI analysis revealed that coronary artery bypass graft, plus mesenchymal stem cell group does not alter regional systolic function at rest. However, under stress this group showed significant improvement in regional systolic function compared to coronary artery bypass graft.