Name: functional assessment of the donor heart during ex situ perfusion: insights from pressure-volume loops and surface echocardiography
Uploaded: 2022-10-11T13:20:00
Description: Watch this Scientific Journal Video about Functional Assessment of the Donor Heart During Ex Situ Perfusion: Insights from Pressure-Volume Loops and Surface Echocardiography at JoVE.com

Georges Lopez Institute, Lissieu, 69380, France
Claudia Lacerda, General Electric Healthcare, Buc, France

The present protocol was approved by the local ethics committee on animal experiments and by the Institutional Committee on Animal Welfare (APAFIS#30483-2021031811339219 v1, Animals Ethics Committee of the University of Paris Saclay, France). Animals were treated in accordance with the Guidelines for the Care and Use of Laboratory Animals developed by the National Institute of Health and with the Principles of Laboratory Animal Care developed by the National Society for Medical Research.
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<ol>
	<li>Lund, 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=The+registry+of+the+international+society+for+heart+and+lung+transplantation:+thirty-second+official+adult+heart+transplantation+report-2015;+focus+theme:+early+graft+failure.">The registry of the international society for heart and lung transplantation: thirty-second official adult heart transplantation report-2015; focus theme: early graft failure.</a> Journal of Heart and Lung Transplant. 34 (10), 1244-1254 (2015).</li><li>. Annual report 2018 Eurotransplant International Foundation Available from: <a target="_blank" href="https://www.eurotransplant.org/cms/mediaobject.php?file=ET_Jaarv">https://www.eurotransplant.org/cms/mediaobject.php?file=ET_Jaarv</a> (2018)</li><li>Guglin, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+to+increase+the+utilization+of+donor+hearts.">How to increase the utilization of donor hearts.</a> Heart Failure Reviews. 20 (1), 95-105 (2015).</li><li>Tuttle-Newhall, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organ+donation+and+utilization+in+the+United+States:+1998-2007.">Organ donation and utilization in the United States: 1998-2007.</a> American Journal of Transplantation. 9 (4), 879-893 (2009).</li><li>Dronavalli, V. B., Banner, N. R., Bonser, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+the+potential+heart+donor.">Assessment of the potential heart donor.</a> Journal of the American College of Cardiology. 56 (5), 352-361 (2010).</li><li>Reich, H. 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=Effects+of+older+donor+age+and+cold+ischemic+time+on+long-term+outcomes+of+heart+transplantation.">Effects of older donor age and cold ischemic time on long-term outcomes of heart transplantation.</a> Texas Heart Institute Journal. 45, 17-22 (2018).</li><li>Dhital, K. K., 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=Adult+heart+transplantation+with+distant+procurement+and+ex-vivo+preservation+of+donor+hearts+after+circulatory+death:+a+case+series.">Adult heart transplantation with distant procurement and ex-vivo preservation of donor hearts after circulatory death: a case series.</a> The Lancet. 385 (9987), 2585-2591 (2015).</li><li>Garry, B. P., Bivens, H. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Seldinger+technique.">The Seldinger technique.</a> Journal of Cardiothoracic Anesthesia. 2 (3), 403 (1988).</li><li>Lang, R. M., 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=Recommendations+for+cardiac+chamber+quantification+by+echocardiography+in+adults:+an+update+from+the+American+Society+of+Echocardiography+and+the+European+Association+of+Cardiovascular+Imaging.">Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging.</a> Journal of the American Society of Echocardiography. 28 (1), 1-39 (2015).</li><li>White, 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=Assessment+of+donor+heart+viability+during+ex+situ+heart+perfusion.">Assessment of donor heart viability during ex situ heart perfusion.</a> Canadian Journal of Physiology and Pharmacology. 93 (10), 893-901 (2015).</li><li>Hatami, S., 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=Myocardial+functional+decline+during+prolonged+ex+situ+heart+perfusion.">Myocardial functional decline during prolonged ex situ heart perfusion.</a> Annals of Thoracic Surgery. 108 (2), 499-507 (2021).</li><li>Hatami, S., 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=The+position+of+the+heart+during+normothermic+ex+situ+heart+perfusion+is+an+important+factor+in+preservation+and+recovery+of+myocardial+function.">The position of the heart during normothermic ex situ heart perfusion is an important factor in preservation and recovery of myocardial function.</a> American Society of Artificial Internal Organs Journal. 67 (11), 1222-1231 (2021).</li><li>Hatami, S., 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=Normothermic+ex+situ+heart+perfusion+in+working+mode:+assessment+of+cardiac+function+and+metabolism.">Normothermic ex situ heart perfusion in working mode: assessment of cardiac function and metabolism.</a> Journal of Visualized Experiments. (143), e58430 (2019).</li><li>Tchouta, 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=Twenty-four-hour+normothermic+perfusion+of+isolated+ex+situ+hearts+using+plasma+exchange.">Twenty-four-hour normothermic perfusion of isolated ex situ hearts using plasma exchange.</a> Journal of Thoracic and Cardiovascular Surgery. 164 (1), 128-138 (2020).</li><li>Ribeiro, 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=Comparing+donor+heart+assessment+strategies+during+ex+situ+heart+perfusion+to+better+estimate+posttransplant+cardiac+function.">Comparing donor heart assessment strategies during ex situ heart perfusion to better estimate posttransplant cardiac function.</a> Transplantation. 104 (9), 1890-1898 (2020).</li><li>Guihaire, 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=Are+pressure-volume+loops+relevant+for+hemodynamic+assessment+during+ex+vivo+heart+perfusion.">Are pressure-volume loops relevant for hemodynamic assessment during ex vivo heart perfusion.</a> Journal of Heart and Lung Transplantation. 39 (10), 1165-1166 (2020).</li><li>Hamed, 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=Serum+lactate+is+a+highly+sensitive+and+specific+predictor+of+post+cardiac+transplant+outcomes+using+the+Organ+Care+System.">Serum lactate is a highly sensitive and specific predictor of post cardiac transplant outcomes using the Organ Care System.</a> Journal of Heart and Lung Transplantation. 28 (2), 71 (2009).</li></ol>

There are some critical steps to consider in the NESP protocol. In situ preliminary assessment of the heart remained important, especially considering the aortic valve that should not present with significant aortic regurgitation (grade 2 or more); otherwise, the resuscitation of the heart will be compromised during the Langendorff period because of impaired coronary perfusion and myocardial ischemia. The initiation of the WM after Langendorff perfusion was a challenging maneuver, requiring at least two persons ...

Heart transplantation is the gold standard treatment for advanced heart failure, but is limited by current organ shortage1. A growing number of donor hearts with extended criteria (age &gt;45 years, cardiovascular risk factors, prolonged low flow, acute left ventricular dysfunction secondary to catecholaminergic storm) are allocated with an increased risk of primary graft failure2. Moreover, hearts donated after controlled circulatory death (DCD) may be presented with myocardial injury secondary to prolonged warm ischemia3. Therefore, there is a need for a better assessment of these donor hearts before transplantation, especially to evaluate their eligibility for heart transplantation4,5. 
Normothermic ex situ perfusion (NESP) preserves the beating heart using warm oxygenated blood. The only commercially available device for NESP preserves the heart in a non-working state (Langendorff mode). This approach was initially applied to expand the preservation of the graft beyond the critical 4 h period of cold ischemia6. Another major advantage of this technology is to provide continuous assessment of myocardial viability based on lactate concentration in the perfusate6. However, this biochemical assessment has never been correlated with post-transplant outcomes to date. Similarly, Langendorff mode for NESP does not allow for hemodynamic and functional evaluation of the heart prior to transplantation. Some authors have reported the potential benefit of intracardiac catheterization during NESP to predict myocardial recovery after transplantation7.
The present report aims to provide a reproducible methodology to evaluate donor heart performance during NESP. We modified the circuit to allow for working mode perfusion and, therefore, for the acquisition of noninvasive functional variables with epicardial echocardiography. Myocardial work index, a load-independent variable, was recorded using pressure-strain loops. We investigated the relationships between myocardial work and hemodynamic variables obtained from intracardiac conductance catheterization.

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	<tbody>
		<tr>
			<td>3T Heater Cooler System</td>
			<td>Liva Nova, Ch&#226;tillon, France</td>
			<td>IM-00727 A</td>
			<td>Extracorporeal Heater Cooler device</td>
		</tr>
		<tr>
			<td>4-0 polypropylene suture</td>
			<td>Peters, bobigny, France</td>
			<td>20S15B</td>
			<td>sutures</td>
		</tr>
		<tr>
			<td>5-0 polypropylene suture</td>
			<td>Peters, bobigny, France</td>
			<td>20S10B</td>
			<td>sutures</td>
		</tr>
		<tr>
			<td>Adenosine</td>
			<td>Efisciens BV, Rotterdam, Netherlands</td>
			<td>9088309</td>
			<td>Drugs for the ex-vivo perfusion</td>
		</tr>
		<tr>
			<td>Adrenaline</td>
			<td>Aguettant, Lyon, France</td>
			<td>600040</td>
			<td>Drugs for the ex-vivo perfusion</td>
		</tr>
		<tr>
			<td>Atracurium</td>
			<td>Pfizer Holding France, Paris, France</td>
			<td>582547</td>
			<td>Drugs for the induction of the anesthesia</td>
		</tr>
		<tr>
			<td>DeltaStream</td>
			<td>Fresenius Medical Care, L&#8217;Arbresle, France</td>
			<td>MEH2C4024</td>
			<td>Extracorporeal blood pump</td>
		</tr>
		<tr>
			<td>EKG epicardial electrodes</td>
			<td>Cardinal Health LLC, Waukegan, Illinois, USA</td>
			<td>31050522</td>
			<td>EKG detection electrodes</td>
		</tr>
		<tr>
			<td>External pacemaker</td>
			<td>Medtronic Inc. Minneapolis, Minneapolis, USA</td>
			<td>5392</td>
			<td>Pacemaker device</td>
		</tr>
		<tr>
			<td>Glucose 5%</td>
			<td>B.Braun Melsungen AG, Melsungen, Germany</td>
			<td>3400891780017</td>
			<td>Drugs for the priming solution</td>
		</tr>
		<tr>
			<td>Heart Perfusion Set, Organ Care System</td>
			<td>Transmedics, Andover, MA, USA</td>
			<td>Ref#1200</td>
			<td>Normothermic ex-vivo heart perfusion device</td>
		</tr>
		<tr>
			<td>Intellivue MX550</td>
			<td>Philips Healthcare, Suresnes, France</td>
			<td>NA</td>
			<td>Permanent monitoring system</td>
		</tr>
		<tr>
			<td>Istat 1</td>
			<td>Abbott, Chicago, Ill, USA</td>
			<td>714336-03O</td>
			<td>Blood Analyzer machine</td>
		</tr>
		<tr>
			<td>Labchart</td>
			<td>AD Instruments Ltd, Paris, France</td>
			<td>LabChart&#160;v8.1.21</td>
			<td>Pressure Volume loops aquisition software</td>
		</tr>
		<tr>
			<td>Magnesium</td>
			<td>Aguettant, Lyon, France</td>
			<td>564 780-6</td>
			<td>Drugs for the cardioplegia</td>
		</tr>
		<tr>
			<td>Magnesium Sulfate</td>
			<td>Aguettant, Lyon, France</td>
			<td>600111</td>
			<td>Drugs for the cardioplegia</td>
		</tr>
		<tr>
			<td>Mannitol 20%</td>
			<td>Macopharma, Mouvoux, France</td>
			<td>3400891694567.00</td>
			<td>Drugs for the cardioplegia</td>
		</tr>
		<tr>
			<td>Methylprednisolone</td>
			<td>Mylan S.A.S, Saint Priest, France</td>
			<td>400005623</td>
			<td>Drugs for the priming solution</td>
		</tr>
		<tr>
			<td>Millar Conductance Catheter</td>
			<td>AD Instruments Ltd, Paris, France</td>
			<td>Ventri-Cath 507</td>
			<td>Pressure Volume loops conductance catheter</td>
		</tr>
		<tr>
			<td>MWI software</td>
			<td>General Electric Healthcare, Chicago, Ill, USA</td>
			<td>NA</td>
			<td>software used for the Ultrasound echocardiographic machine</td>
		</tr>
		<tr>
			<td>Orotracheal probe</td>
			<td>Smiths medical ASD, Inc., Minneapolis, Minneapolis, USA</td>
			<td>100/199/070</td>
			<td>probe for the intubation during anesthesia</td>
		</tr>
		<tr>
			<td>Potassium chloride 10%</td>
			<td>B.Braun Melsungen AG, Melsungen, Germany</td>
			<td>3400892691527.00</td>
			<td>Drugs for the cardioplegia</td>
		</tr>
		<tr>
			<td>Propofol</td>
			<td>Zoetis France, Malakoff, France</td>
			<td>8083511</td>
			<td>Drugs for the induction of the anesthesia</td>
		</tr>
		<tr>
			<td>Quadrox-I small Adult Oxygenator</td>
			<td>Getinge, G&#246;teborg, Sweden</td>
			<td>BE-HMO 50000</td>
			<td>Extracorporeal blood oxygenator</td>
		</tr>
		<tr>
			<td>Ringer solution</td>
			<td>B.Braun Melsungen AG, Melsungen, Germany</td>
			<td>DKE2323</td>
			<td>Drugs for the cardioplegia</td>
		</tr>
		<tr>
			<td>Sodium Bicarbonate</td>
			<td>Laboratoire Renaudin, itxassou, France</td>
			<td>3701447</td>
			<td>Drugs for the cardioplegia</td>
		</tr>
		<tr>
			<td>Sodium chloride</td>
			<td>Aguettant, Lyon, France</td>
			<td>606726</td>
			<td>Drugs for the priming solution</td>
		</tr>
		<tr>
			<td>Swan Ganz Catheter</td>
			<td>Merit Medical, south jordan, utah, USA</td>
			<td>5041856</td>
			<td>Right pressure and cardiac output probe</td>
		</tr>
		<tr>
			<td>Tiletamine</td>
			<td>Virbac France, Carros, France</td>
			<td>3597132126021.00</td>
			<td>Drugs for the induction of the anesthesia</td>
		</tr>
		<tr>
			<td>Transesophagus probe (3&#8211;8 MHz 6VT)</td>
			<td>General Electric Healthcare, Chicago, Ill, USA</td>
			<td>NA</td>
			<td>Ultrasound echocardiographic transesophagus probe</td>
		</tr>
		<tr>
			<td>Vivid E95 ultraSound Machine</td>
			<td>General Electric Healthcare, Chicago, Ill, USA</td>
			<td>NA</td>
			<td>Ultrasound echocardiographic machine</td>
		</tr>
		<tr>
			<td>Xyloca&#239;ne 2%</td>
			<td>Aspen, Reuil-malmaison, France</td>
			<td>600550</td>
			<td>Drugs for the cardioplegia</td>
		</tr>
		<tr>
			<td>Zolazepam</td>
			<td>Virbac France, Carros, France</td>
			<td>3597132126021.00</td>
			<td>Drugs for the induction of the anesthesia</td>
		</tr>
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</table>

functional assessment of the donor heart during ex situ perfusion: insights from pressure-volume loops and surface echocardiography

Heart transplantation remains the gold standard treatment for advanced heart failure. However, the current critical organ shortage has resulted in the allocation of a growing number of donor hearts with extended criteria. These marginal grafts are associated with a high risk of primary graft failure and may benefit from ex situ perfusion before transplant. This technology allows for extended organ preservation using warm oxygenated blood perfusion with continuous metabolic monitoring. The only NESP device currently available for clinical practice perfuses the organ in an unloaded non-working state, which does not allow for functional assessment of the beating heart. We therefore developed an original platform of NESP in working mode conditions with adjustment of left ventricular preload and afterload. This protocol was applied in porcine hearts. Ex situ functional assessment of the heart was achieved with intracardiac conductance catheterization and surface echocardiography. Along with a description of the experimental protocol, we herein report the main results, as well as pearls and pitfalls associated with the acquisition of pressure-volume loops and myocardial power during NESP. Correlations between hemodynamic findings and ultrasound variables are of major interest, especially for further rehabilitation of donor hearts before transplantation. This protocol aims to improve the assessment of donor hearts to both increase the donor pool and reduce the incidence of primary graft failure.

We herein described a NESP protocol in a monoventricular working state, using a modified heart perfusion module usually employed in clinical practice for Langendorff perfusion of the donor heart before transplantation. This piglet model of NESP using the present custom module was developed in 2019. The modifications of the circuit were minor, as most of the perfusion circuit was re-used for experiments. The cap of the module provided a flexible and waterproof membrane to protect the heart during transportation. It also a...

Watch this Scientific Journal Video about Functional Assessment of the Donor Heart During Ex Situ Perfusion: Insights from Pressure-Volume Loops and Surface Echocardiography at JoVE.com

Functional Assessment of the Donor Heart During Ex Situ Perfusion: Insights from Pressure-Volume Loops and Surface Echocardiography

A reliable noninvasive approach for functional assessment of the donor heart during normothermic ex situ heart perfusion (NESP) is lacking. We herein describe a protocol for ex situ assessment of myocardial performance using the epicardial echocardiography and conductance catheter method.

Functional Assessment of the Donor Heart During Ex Situ Perfusion: Insights from Pressure-Volume Loops and Surface Echocardiography

Heart transplantation remains the gold standard treatment for advanced heart failure. However, the current critical organ shortage has resulted in the ...

Hemodynamic assessment of the heart during isolated Ex situ perfusion is poorly described. This protocol provides a method to evaluate Ex situ cardiac performances in working mode. Our approach co compares invasive PV loop technique to epicardial echocardiography for functional assessment of their heart during isolated Ex situ perfusion.This approach requires a team experience in Ex situ heart perfusion, along with involvement of a cardiologist trained for transoeosphageal echocardiography. A major concerns in heart transplantation is the risk of primary graft failure. Our approach using epicardial echocardiography provides an assessment of the heart before transplant during Ex situ perfusion.This non-invasive method could be written applied during Ex situ heart perfusion prior to transplant. Begin by placing four zero polypropylene sutures on the right atrium and on the ascending aorta of the anesthetized animal to secure cannulation with tourniquets. Infuse heparin and carefully dissect the aortic root.Then insert a double staged venous cannula in the right atrium for blood collection and a single lumen cannula in the ascending aorta for cardioplegia infusion. After isolating the superior and inferior vena cava connect the venous cannula to a blood collecting bag containing 10, 000 units of unfractionated heparin. Place the piglet body in the Trendelenberg position to improve blood drainage into the collecting bag.Proceed to heart procurement keeping two centimeters of the pulmonary trunk along with the left atrium posterior wall. Place the heart in a four degree Celsius saline solution and separate the ascending aorta from the pulmonary trunk. Verify that the aortic valve and the coronary ostea are not injured.Insert four pledged four zero polypropylene stitches, five millimeters below the distal section of the ascending aorta and insert the infusion cannula into the aorta. Tighten a hose clamp around the aorta to secure the cannula. Insert a drainage cannula into the pulmonary trunk and secure it with a three zero polypropylene running suture.Close the inferior and superior vena cava with five zero polypropylene running sutures. Close the left atrium posterior wall with a four zero polypropylene running suture. Insert a left vent cannula through the posterior wall of the left atrium and snare a tourniquet around.Insert a preloaded cannula into the left atrial appendage and snare a tourniquet around. Decrease the pump flow to 200 milliliters per minute. Connect the heart to the aortic connector after de-airing the connector.Adjust the aortic pressure to 30 millimeters of mercury at room temperature. During resuscitation, perform a smooth cardiac massage until a sinus rhythm is restored. Slowly increase the pump flow within 15 to 25 minutes by steps of 50 milliliters per minute to achieve an aortic pressure of 65 millimeters of mercury.At the same time, increase the profused temperature by steps of two to four degrees Celsius to reach 37 degrees Celsius. Once the required aortic pressure and profuse a temperature is reached deliver an electric shock at five joules if needed and repeat until the sinus rhythm is restored. Secure an epicardial electrode to the right ventricular posterior wall and connect to an external pacemaker.Then connect the pulmonary cannula to the coronary flow line. Open the preload line and adjust the pump flow to ensure stable filling of the preload reservoir. Open the aortic afterload line and clamp the main line of the circuit used for Langandorf perfusion.The afterload reservoir will be progressively filled up. Ensure the drainage of the reservoir by an overflow line which brings the profused back to the main reservoir of the circuit. Initiate the infusion of dobutamine at 0.04 milligrams per minute.Then remove the vent. Clean the seven French pigtail conductance catheter with saline solution and connect it to the hardware interface. Gently push the catheter into the introducer 8 French sheath previously inserted through the left atrium roof to be aligned with the mitral valve.Stop epicardial pacing of the heart to avoid interference with the conductance signal. Record data in a steady state when the signal is stabilized. Select a series of 10 consecutive loops and open the analysis software.To obtain the end systolic and end diastolic pressure volume relation, record the signal during preload occlusion. Gradually clamp the atrial profusion line until preload reduction is effective. Then slowly release the clamp.After placing a sterile drape around the heart apply the probe to the upper wall of the left atrium and manually rotate the transducer until a four chamber view is obtained. Then run the ultrasound probe monitor to obtain three and two chamber views. To assess the MWI proceed to the acquisition of four, three, and two chamber views and record simultaneous arterial pressure.Assess the global longitudinal strain using these views and open MWI software. Use the invasive blood pressure detected by the external sensor on the perfusion circuit using loop acquisition. Manually notify the software of the exact opening and closing times of the aortic and mitral valves.Echocardiographic assessment during working mode perfusion was performed in the custom setup. All three left ventricular views were obtained at any time point in all experiments. Mean left ventricular ejection fraction global longitudinal strain and M W I was approximately 40.8%minus 8.0%and 65 millimeters of mercury respectively.Hemodynamic parameters were assessed by either conductance catheter or surface echocardiography during work mode perfusion. During the work mode perfusion a significant decrease was observed in M W I over time in all experiments. A similar decrease was observed in the cardiac output and other parameters related to the end systolic pressure volume relationship.The echocardiographic probe has to be located on the roof of the left atrium. Stable requisition of at least three to six myocardial cycles must be performed correctly. A metabolic assessment of the myocardial tissue and the endothelial function would bring a complimentary evaluation of the heart graft during ex situ heart perfusion to optimize perfusion settings.

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Research

JoVE Journal

Medicine

Cardiac Catheterization in Mice to Measure the Pressure Volume Relationship: Investigating the Bowditch Effect

Animal models that mimic human cardiac disorders have been created to test potential therapeutic strategies. A key component to evaluating these strategies is to examine their effects on heart function. There are several techniques to measure in vivo cardiac mechanics (e.g., echocardiography, pressure/volume relations, etc.). Compared to echocardiography, real-time left ventricular (LV) pressure/volume analysis via catheterization is more precise and insightful in assessing LV function. Additionally, LV pressure/volume analysis provides the ability to instantaneously record changes during manipulations of contractility (e.g., &#946;-adrenergic stimulation) and pathological insults (e.g., ischemia/reperfusion injury). In addition to the maximum (+dP/dt) and minimum (-dP/dt) rate of pressure change in the LV, an accurate assessment of LV function via several load-independent indexes (e.g., end systolic pressure volume relationship and preload recruitable stroke work) can be attained. Heart rate has a significant effect on LV contractility such that an increase in the heart rate is the primary mechanism to increase cardiac output (i.e., Bowditch effect). Thus, when comparing hemodynamics between experimental groups, it is necessary to have similar heart rates. Furthermore, a hallmark of many cardiomyopathy models is a decrease in contractile reserve (i.e., decreased Bowditch effect). Consequently, vital information can be obtained by determining the effects of increasing heart rate on contractility. Our and others data has demonstrated that the neuronal nitric oxide synthase (NOS1) knockout mouse has decreased contractility. Here we describe the procedure of measuring LV pressure/volume with increasing heart rates using the NOS1 knockout mouse model.

This article describes the measurement of murine left ventricular function via pressure/volume analysis at different heart rates.

Animal models that mimic human cardiac disorders have been created to test potential therapeutic strategies. A key component to evaluating these ...

Ex Situ Normothermic Machine Perfusion of Donor Livers

In contrast to conventional static cold preservation (0-4 &#176;C), ex situ machine perfusion may provide better preservation of donor livers. Continuous perfusion of organs provides the opportunity to improve organ quality and allows ex situ viability assessment of donor livers prior to transplantation. This video article provides a step by step protocol for ex situ normothermic machine perfusion (37 &#176;C) of human donor livers using a device that provides a pressure and temperature controlled pulsatile perfusion of the hepatic artery and continuous perfusion of the portal vein. The perfusion fluid is oxygenated by two hollow fiber membrane oxygenators and the temperature can be regulated between 10 &#176;C and 37 &#176;C. During perfusion, the metabolic activity of the liver as well as the degree of injury can be assessed by biochemical analysis of samples taken from the perfusion fluid. Machine perfusion is a very promising tool to increase the number of livers that are suitable for transplantation.

Ex Situ Normothermic Machine Perfusion of Donor Livers

Here we present a protocol describing oxygenated ex situ machine perfusion of donor liver grafts. This article contains a step by step protocol to procure and prepare the liver graft for machine perfusion, prepare the perfusion fluid, prime the perfusion machine and perform oxygenated normothermic machine perfusion of the liver graft.

In contrast to conventional static cold preservation (0-4 &#176;C), ex situ machine perfusion may provide better preservation of donor livers. Continuous ...

Real-time Pressure-volume Analysis of Acute Myocardial Infarction in Mice

Acute myocardial infarction can lead to acute heart failure and cardiogenic shock. The evaluation of hemodynamics is critical for the evaluation of any potential therapeutic approach directed against acute left ventricular (LV) dysfunction. Current imaging modalities (e.g., echocardiography and magnetic resonance imaging) have several limitations since data on LV pressure cannot directly be measured. LV catheterization in mice undergoing coronary artery occlusion could serve as a novel method for a real-time evaluation of LV function.
At the beginning of the procedure, mice were anesthetized followed by endotracheal intubation. For LV catheterization, the right carotid artery was exposed via middle-neck incision. The catheter was introduced and placed into the LV cavity. Left thoracotomy was conducted and the left main coronary artery (LCA) was ligated. To induce reperfusion, the suture was released after 45 min. Pressure-volume data was recorded at all times.
Ligation of the LCA caused a decrease in LV systolic function as evidenced by a 30% reduction in stroke volume, LV ejection fraction (EF), and cardiac output. Maximum dP/dt as a parameter for LV contractility was also significantly reduced and diastolic function was severely impaired (minimum dP/dt -40%). Reperfusion over a period of 20 min did not lead to a complete recovery of LV function.
Real-time pressure-volume analysis served as a valid procedure for monitoring cardiac function during acute myocardial infarction in mice. Maintaining stable anesthesia and a standardized surgical approach was crucial to ensure valid results. As the early phase of acute myocardial infarction is critical for morbidity and mortality, the delineated method could be beneficial for preclinical evaluation of new strategies for cardioprotection.

Acute myocardial infarction in mice induces acute but incompletely characterized changes in left ventricular (LV) function. LV catheterization in mice undergoing coronary artery occlusion serves as a novel method for a real-time evaluation of LV function.

Acute myocardial infarction can lead to acute heart failure and cardiogenic shock. The evaluation of hemodynamics is critical for the evaluation of any ...

Normothermic Ex Situ Heart Perfusion in Working Mode: Assessment of Cardiac Function and Metabolism

The current standard method for organ preservation (cold storage, CS), exposes the heart to a period of cold ischemia that limits the safe preservation time and increases the risk of adverse post-transplantation outcomes. Moreover, the static nature of CS does not allow for organ evaluation or intervention during the preservation interval. Normothermic ex situ heart perfusion (ESHP) is a novel method for preservation of the donated heart that minimizes cold ischemia by providing oxygenated, nutrient-rich perfusate to the heart. ESHP has been shown to be non-inferior to CS in the preservation of standard-criteria donor hearts and has also facilitated the clinical transplantation of the hearts donated after the circulatory determination of death. Currently, the only available clinical ESHP device perfuses the heart in an unloaded, non-working state, limiting assessments of myocardial performance. Conversely, ESHP in working mode provides the opportunity for comprehensive evaluation of cardiac performance by assessment of functional and metabolic parameters under physiologic conditions. Moreover, earlier experimental studies have suggested that ESHP in working mode may result in improved functional preservation. Here, we describe the protocol for ex situ perfusion of the heart in a large mammal (porcine) model, which is reproducible for different animal models and heart sizes. The software program in this ESHP apparatus allows for real-time and automated control of the pump speed to maintain desired aortic and left atrial pressure and evaluates a variety of functional and electrophysiological parameters with minimal need for supervision/manipulation.

Normothermic ex situ heart perfusion (ESHP), preserves the heart in a beating, semi-physiologic state. When performed in a working mode, ESHP provides the opportunity to perform sophisticated assessments of donor heart function and organ viability. Here, we describe our method for myocardial performance evaluation during ESHP.

The current standard method for organ preservation (cold storage, CS), exposes the heart to a period of cold ischemia that limits the safe preservation ...

Biventricular Assessment of Cardiac Function and Pressure-Volume Loops by Closed-Chest Catheterization in Mice

Assessment of cardiac function is essential to conduct cardiovascular and pulmonary-vascular preclinical research. Pressure-volume loops (PV loops) generated by recording both pressure and volume during cardiac catheterization are vital when assessing both systolic and diastolic cardiac function. Left and right heart function are closely related, reflected in ventricular interdependence. Thus, recording biventricular function in the same animal is important to get a complete assessment of cardiac function. In this protocol, a closed chest approach to cardiac catheterization consistent with the way catheterization is performed in patients is adopted in mice. While challenging, the closed chest strategy is a more physiological approach, because opening the chest results in major changes in preload and afterload that create artifacts, most notably a fall in systemic blood pressure. While high-resolution echocardiography is used to assess rodents, cardiac catheterization is invaluable, particularly when assessing diastolic pressures in both ventricles.
Described here is a procedure to perform invasive, closed chest, sequential left and right ventricular pressure-volume (PV) loops in the same animal. PV loops are acquired using&#160;admittance technology with a mouse pressure-volume catheter and pressure-volume system acquisition. The procedure is described, beginning with the neck dissection, which is required to access the right jugular vein and the right carotid artery, to the insertion and positioning of the catheter, and finally the data acquisition. Then, the criteria required to ensure the acquisition of high-quality PV loops are discussed. Finally, the analysis of the left and right ventricular PV loops and the different hemodynamic parameters available to quantify systolic and diastolic ventricular function are briefly described.

Presented here is a protocol to assess biventricular heart function in mice by generating pressure-volume (PV) loops from the right and left ventricle in the same animal using closed chest catheterization. The focus is on the technical aspect of surgery and data acquisition.

Assessment of cardiac function is essential to conduct cardiovascular and pulmonary-vascular preclinical research. Pressure-volume loops (PV loops) ...

Morphological and Functional Assessment of the Right Ventricle Using 3D Echocardiography

Traditionally, it was believed that the right side of the heart has a minor role in circulation; however, more and more data suggest that right ventricular (RV) function has strong diagnostic and prognostic power in various cardiovascular disorders. Due to its complex morphology and function, assessment of the RV by conventional two-dimensional echocardiography is limited: the everyday clinical practice usually relies on simple linear dimensions and functional measures. Three-dimensional (3D) echocardiography overcame these limitations by providing volumetric quantification of the RV free of geometrical assumptions. Here, we offer a step-by-step guide to obtain and analyze 3D echocardiographic data of the RV using the leading commercially available software. We will quantify 3D RV volumes and ejection fraction. Several technical aspects may help to improve the quality of RV acquisition and analysis as well, which we present in a practical manner. We review the current opportunities and the limiting factors of this method and also highlight the potential applications of 3D RV assessment in current clinical practice.

Here, we provide a step-by-step acquisition and analysis protocol for the 3D volumetric assessment of the right ventricle, mainly focusing on the practical aspects that maximize the feasibility of this technique.

Traditionally, it was believed that the right side of the heart has a minor role in circulation; however, more and more data suggest that right ...

Normothermic Negative Pressure Ventilation Ex Situ Lung Perfusion: Evaluation of Lung Function and Metabolism

Lung transplantation (LTx) remains the standard of care for end-stage lung disease. A shortage of suitable donor organs and concerns over donor organ quality exacerbated by excessive geographic transportation distance and stringent donor organ acceptance criteria pose limitations to current LTx efforts. Ex situ lung perfusion (ESLP) is an innovative technology that has shown promise in attenuating these limitations. The physiologic ventilation and perfusion of the lungs outside of the inflammatory milieu of the donor body affords ESLP several advantages over traditional cold static preservation (CSP). There is evidence that negative pressure ventilation (NPV) ESLP is superior to positive pressure ventilation (PPV) ESLP, with PPV inducing more significant ventilator-induced lung injury, pro-inflammatory cytokine production, pulmonary edema, and bullae formation. The NPV advantage is perhaps due to the homogenous distribution of intrathoracic pressure across the entire lung surface. The clinical safety and feasibility of a custom NPV-ESLP device have been demonstrated in a recent clinical trial involving extender criteria donor (ECD) human lungs. Herein, the use of this custom device is described in a juvenile porcine model of normothermic NPV-ESLP over a 12 h duration, paying particular attention to management techniques. Pre-surgical preparation, including ESLP software initialization, priming, and de-airing of the ESLP circuit, and the addition of anti-thrombotic, anti-microbial, and anti-inflammatory agents, is specified. The intraoperative techniques of central line insertion, lung biopsy, exsanguination, blood collection, cardiectomy, and pneumonectomy are described. Furthermore, particular focus is paid to anesthetic considerations, with anesthesia induction, maintenance, and dynamic modifications outlined. The protocol also specifies the custom device's initialization, maintenance, and termination of perfusion and ventilation. Dynamic organ management techniques, including alterations in ventilation and metabolic parameters to optimize organ function, are thoroughly described. Finally, the physiological and metabolic assessment of lung function is characterized and depicted in the representative results.

Normothermic Negative Pressure Ventilation Ex Situ Lung Perfusion: Evaluation of Lung Function and Metabolism

This paper describes a porcine model of negative pressure ventilation ex situ lung perfusion, including procurement, attachment, and management on the custom-made platform. Focus is made on anesthetic and surgical techniques, as well as troubleshooting.

Lung transplantation (LTx) remains the standard of care for end-stage lung disease. A shortage of suitable donor organs and concerns over donor organ ...

Muscle Function Obtained with Motion Mode Ultrasound and Surface Electromyography during Core Endurance Exercise

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured between fascial borders at a given time point during an exercise. This selected time point produces a one-dimensional image resulting in real-time, live observation of anatomy. Ultrasound used during functional movement can be referred to as dynamic ultrasound; this is feasible and reliable with the use of a linear transducer, elastic belt, and foam block to secure consistent transducer placement. The lateral abdominal wall is commonly investigated using ultrasound due to the overlapping nature of the muscles. Surface electromyography (sEMG) can complement M-mode ultrasound imaging because it measures the electrical representation of muscle activation. There is minimal evidence using M-mode ultrasound and sEMG simultaneously during core exercise. Exercises that challenge the core musculature involve both isometric holds (e.g., side plank), as well as oscillatory extremity movements (e.g., dead bug). In this study, both instruments will be used simultaneously to measure core muscle function during exercise. Ultrasound measurements will be obtained using a linear transducer and ultrasound unit, and sEMG measurements will be acquired from a wireless sEMG system. To make comparisons between participants and exercises, normalization methods using static, exercise starting positions for both instruments will be used. An activation ratio will be used for ultrasound and calculated by dividing the contracted thickness (thickness during a time point of exercise) by the rested (starting position) thickness. Muscle thickness will be measured in centimeters from the superior inferior fascial border to inferior superior fascial border. These methods aim to offer an innovative and practical measurement of muscle function with M-mode ultrasound and sEMG during core endurance exercises.

This protocol uses motion mode ultrasound and surface electromyography simultaneously to measure muscle function of the core. Muscle thickness and activation of the local stabilizers (e.g., transverse abdominis, internal oblique) and global movers (e.g., external oblique) is achievable during specific time points of the side plank and dead bug exercises.

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured ...

Rat Model of Normothermic Ex-Situ Perfused Heterotopic Heart Transplantation

Heart transplantation is the most effective therapy for end-stage heart failure. Despite the improvements in therapeutic approaches and interventions, the number of heart failure patients waiting for transplantation is still increasing. The normothermic ex situ preservation technique has been established as a comparable method to the conventional static cold storage technique. The main advantage of this technique is that donor hearts can be preserved for up to 12 h in a physiologic condition. Moreover, this technique allows resuscitation of the donor hearts after circulatory death and applies required pharmacologic interventions to improve donor function after implantation. Numerous animal models have been established to improve normothermic ex situ preservation techniques and eliminate preservation-related complications. Although large animal models are easy to handle compared to small animal models, it is costly and challenging. We present a rat model of normothermic ex situ donor heart preservation followed by heterotopic abdominal transplantation. This model is relatively cheap and can be accomplished by a single experimenter.

Here, we present an assessment protocol of a heterotopically implanted heart after normothermic ex situ preservation in the rat model.

Heart transplantation is the most effective therapy for end-stage heart failure. Despite the improvements in therapeutic approaches and interventions, the ...

Advancing Lung Transplantation with PolyhHb-Based Perfusion in Rat EVLP Models

Exploring Alternative Perfusion Solutions Using Next-Generation Polymerized Hemoglobin-Based Oxygen Carriers in a Model of Rat Ex Vivo Lung Perfusion

Lung transplantation is hampered by the lack of suitable donors. Previously, donors that were thought to be marginal or inadequate were discarded. However, new and exciting technology, such as ex vivo lung perfusion (EVLP), offers lung transplant providers extended assessment for marginal donor allografts. This dynamic assessment platform has led to an increase in lung transplantation and has allowed providers to use donors that were previously discarded, thus expanding the donor pool. Current perfusion techniques use cellular or acellular perfusates, and both have distinct advantages and disadvantages. Perfusion composition is critical to maintaining a homeostatic environment, providing adequate metabolic support, decreasing inflammation and cellular death, and ultimately improving organ function. Perfusion solutions must contain sufficient protein concentration to maintain appropriate oncotic pressure. However, current perfusion solutions often lead to fluid extravasation through the pulmonary endothelium, resulting in inadvertent pulmonary edema and damage. Thus, it is necessary to develop novel perfusion solutions that prevent excessive damage while maintaining proper cellular homeostasis. Here, we describe the application of a polymerized human hemoglobin (PolyhHb)-based oxygen carrier as a perfusate and the protocol in which this perfusion solution can be tested in a model of rat EVLP. The goal of this study is to provide the lung transplant community with key information in designing and developing novel perfusion solutions, as well as the proper protocols to test them in clinically relevant translational transplant models.

Author Spotlight: Utilizing Next-Generation Polymerized Human Hemoglobin for Improved Donor Lung Evaluation and Preservation in Rats

Here, we describe the application of a polymerized human hemoglobin (PolyhHb)-based oxygen carrier as a perfusate and the protocol in which this perfusion solution can be tested in a model of rat ex vivo lung perfusion.