We would like to thank Duke Large Animal Surgical Core and Duke Perfusion Services for their assistance during these procedures. We would also like to thank Paul Lezberg and TransMedics, Inc. for support.

<ol>
	<li>Virani, S. 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=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), 254 (2021).</li><li>Stehlik, J., Kobashigawa, J., Hunt, S. A., Reichenspurner, H., Kirklin, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Honoring+50+years+of+clinical+heart+transplantation+in+circulation:+in-depth+state-of-the-art+review.">Honoring 50 years of clinical heart transplantation in circulation: in-depth state-of-the-art review.</a> Circulation. 137 (1), 71-87 (2018).</li><li>Kadner, A., Chen, R. H., Adams, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heterotopic+heart+transplantation:+experimental+development+and+clinical+experience.">Heterotopic heart transplantation: experimental development and clinical experience.</a> European Journal of Cardiothorac Surgery. 17 (4), 474-481 (2000).</li><li>Hastings, C. 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=Drug+and+cell+delivery+for+cardiac+regeneration.">Drug and cell delivery for cardiac regeneration.</a> Advanced Drug Delivery Reviews. 84, 85-106 (2015).</li><li>Sahoo, S., Kariya, T., Ishikawa, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeted+delivery+of+therapeutic+agents+to+the+heart.">Targeted delivery of therapeutic agents to the heart.</a> Nature Reviews. Cardiology. 18 (6), 389-399 (2021).</li><li>Stamp, N. 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=Successful+heart+transplant+after+ten+hours+out-of-body+time+using+the+TransMedics+Organ+Care+System.">Successful heart transplant after ten hours out-of-body time using the TransMedics Organ Care System.</a> Heart, Lung &amp; Circulation. 24 (6), 611-613 (2015).</li><li>Ragalie, W. S., Ardehali, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+status+of+normothermic+ex-vivo+perfusion+of+cardiac+allografts.">Current status of normothermic ex-vivo perfusion of cardiac allografts.</a> Current Opinion in Organ Transplantation. 25 (3), 237-240 (2020).</li><li>Koerner, M. 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=Normothermic+ex+vivo+allograft+blood+perfusion+in+clinical+heart+transplantation.">Normothermic ex vivo allograft blood perfusion in clinical heart transplantation.</a> Heart Surgery Forum. 17 (3), 141-145 (2014).</li><li>Rosenbaum, D. 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=Perfusion+preservation+versus+static+preservation+for+cardiac+transplantation:+effects+on+myocardial+function+and+metabolism.">Perfusion preservation versus static preservation for cardiac transplantation: effects on myocardial function and metabolism.</a> Journal of Heart and Lung Transplantation. 27 (1), 93-99 (2008).</li><li>Cullen, P. P., Tsui, S. S., Caplice, N. M., Hinchion, 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=A+state-of-the-art+review+of+the+current+role+of+cardioprotective+techniques+in+cardiac+transplantation.">A state-of-the-art review of the current role of cardioprotective techniques in cardiac transplantation.</a> Interactive Cardiovascular and Thoracic Surgery. 32 (5), 683-694 (2021).</li><li>Rurik, J. G., Aghajanian, H., Epstein, 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=Immune+cells+and+immunotherapy+for+cardiac+injury+and+repair.">Immune cells and immunotherapy for cardiac injury and repair.</a> Circulation Research. 128 (11), 1766-1779 (2021).</li><li>Rincon, M. Y., VandenDriessche, T., Chuah, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+therapy+for+cardiovascular+disease:+advances+in+vector+development,+targeting,+and+delivery+for+clinical+translation.">Gene therapy for cardiovascular disease: advances in vector development, targeting, and delivery for clinical translation.</a> Cardiovascular Research. 108 (1), 4-20 (2015).</li><li>Kieserman, J. M., Myers, V. D., Dubey, P., Cheung, J. Y., Feldman, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+landscape+of+heart+failure+gene+therapy.">Current landscape of heart failure gene therapy.</a> Journal of the American Heart Association. 8 (10), 012239 (2019).</li><li>Perin, E. C., Perin, E. C., Miller, L. W., Taylor, D. A., Wilkerson, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Stem cell and gene therapy for cardiovascular disease. , 279-287 (2016).</li><li>Bishawi, 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=A+normothermic+ex+vivo+organ+perfusion+delivery+method+for+cardiac+transplantation+gene+therapy.">A normothermic ex vivo organ perfusion delivery method for cardiac transplantation gene therapy.</a> Scientific Reports. 9 (1), 8029 (2019).</li><li>Hulot, J. S., Ishikawa, K., Hajjar, 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=Gene+therapy+for+the+treatment+of+heart+failure:+promise+postponed.">Gene therapy for the treatment of heart failure: promise postponed.</a> European Heart Journal. 37 (21), 1651-1658 (2016).</li><li>Ho, C. 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=Molecular+characterization+of+swine+leucocyte+antigen+class+I+genes+in+outbred+pig+populations.">Molecular characterization of swine leucocyte antigen class I genes in outbred pig populations.</a> Animal Genetics. 40 (4), 468-478 (2009).</li><li>Ho, C. 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=Molecular+characterization+of+swine+leucocyte+antigen+class+II+genes+in+outbred+pig+populations.">Molecular characterization of swine leucocyte antigen class II genes in outbred pig populations.</a> Animal Genetics. 41 (4), 428-432 (2010).</li></ol>

Paul Lezberg is employed by TransMedics, Inc. Carmelo Milano received a financial gift from TransMedics, Inc. to fund heterotopic heart transplant surgeries. Michelle Mendiola Pla is supported by T32HL007101. The other authors have no conflicts of interest to declare.

Delivery of therapeutics during ex vivo perfusion in cardiac transplantation offers a strategy to modify the allograft and potentially improve transplant outcomes. The protocol presented here incorporates the state-of-the-art normothermic ex vivo sanguinous perfusion storage and offers promising potential to test isolated delivery of cell, gene, or immunotherapies to the allograft11,12,13. To date, cardiac deli...

Heart failure is a condition that affects an estimated 6 million adults in the United States and is projected to increase to 8 million adults by the year 20301. Cardiac transplantation is the gold standard treatment for end stage heart failure. However, it is not without its limitations and complications. It remains limited by the number of available donor hearts, primary graft dysfunction, rejection of the heart, and the side effects of long-term immunosuppression2. These limitations are particularly important in young recipients who may experience allograft failure and require subsequent re-transplantation to achieve normal life expectancy.
An ideal intervention to overcome these limitations would treat entire cardiac allografts with therapeutics prior to implantation into the recipient that can improve the viability of the allograft and confer &#34;cardioprotection.&#34; Such interventions would be given prophylactically to minimize the incidence of ischemic insults, allograft rejection, cardiac allograft vasculopathy, and even repair marginal allografts. Translational studies for developing these types of interventions require a large-animal model of cardiac transplantation to allow for the long-term surveillance of the cardiac graft. The porcine, heterotopic heart transplantation model in the intraabdominal position has proven ideal for this purpose. Heart transplantation in this position allows for testing the effects of novel therapies and assessing the immunopathology of graft rejection. Additionally, the heterotopic model is advantageous over the orthotopic model due to better overall survival of the recipient, no requirement for cardiopulmonary bypass, and no requirement of the graft to maintain the recipient&#39;s circulation3.
Effective delivery of therapeutic interventions to the heart, such as gene, cell, or immuno- therapy, is a significant barrier to clinical application4,5. The technology introduced by ex vivo perfusion devices allows grafts to be continually perfused, maintaining them in a nonworking but metabolically active state6,7,8,9. This offers a unique opportunity to treat a whole heart with advanced therapeutics while minimizing the potential side effects of systemic delivery10,11,12,13. Another advantage of utilizing ex vivo perfusion devices for therapeutic delivery is that they allow the administration of medications to the coronary circulation over extended periods that are not feasible using traditional cold static storage methods. This allows for more global delivery of the therapeutics to the graft14. Using the protocol presented here, we successfully delivered the firefly luciferase gene to a whole porcine cardiac graft using adenoviral vectors15. The aim of this protocol is to provide a reproducible and robust approach for achieving delivery of a therapeutic to the entire cardiac allograft prior to transplantation.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0 Looped Maxon suture</td>
			<td>Covidien</td>
			<td>GMM-341L</td>
			<td>Used to close fascia of the laparotomy incision</td>
		</tr>
		<tr>
			<td>0 Silk ties</td>
			<td>Medtronic, Inc</td>
			<td>S346</td>
			<td></td>
		</tr>
		<tr>
			<td>18 G Angiocath</td>
			<td>BD</td>
			<td>381144</td>
			<td>Used to de-air the left ventricle of the donor heart after implantation</td>
		</tr>
		<tr>
			<td>20 Fr LV vent</td>
			<td>Medtronic, Inc</td>
			<td>12002</td>
			<td></td>
		</tr>
		<tr>
			<td>2-0 Silk sutures</td>
			<td>Ethicon, Inc.</td>
			<td>SA11G</td>
			<td></td>
		</tr>
		<tr>
			<td>2-0 Silk ties</td>
			<td>Ethicon, Inc.</td>
			<td>SA65H</td>
			<td></td>
		</tr>
		<tr>
			<td>2-0 Vicryl suture</td>
			<td>Ethicon, Inc.</td>
			<td>J259H</td>
			<td></td>
		</tr>
		<tr>
			<td>24 Fr venous cannula</td>
			<td>Medtronic, Inc</td>
			<td>68124</td>
			<td></td>
		</tr>
		<tr>
			<td>3-0 Prolene sutures</td>
			<td>Ethicon, Inc.</td>
			<td>8522</td>
			<td></td>
		</tr>
		<tr>
			<td>4-0 Monocryl suture</td>
			<td>Ethicon, Inc.</td>
			<td>Y469G</td>
			<td></td>
		</tr>
		<tr>
			<td>4-0 Prolene sutures</td>
			<td>Ethicon, Inc.</td>
			<td>8521</td>
			<td></td>
		</tr>
		<tr>
			<td>Animal hair cutting clipper</td>
			<td>Wahl</td>
			<td>8786-452</td>
			<td></td>
		</tr>
		<tr>
			<td>Aortic clamp</td>
			<td>V. Mueller</td>
			<td>CH6201</td>
			<td></td>
		</tr>
		<tr>
			<td>Army Navy retractor</td>
			<td>V. Mueller</td>
			<td>SU3660</td>
			<td></td>
		</tr>
		<tr>
			<td>ATF 40, Cell saver disposable set</td>
			<td>Fresenius Kabi</td>
			<td>9108494</td>
			<td>Cell saver device insert</td>
		</tr>
		<tr>
			<td>Balfour retractor</td>
			<td>V. Mueller</td>
			<td>SU3042</td>
			<td>Used as an abdominal wall retractor</td>
		</tr>
		<tr>
			<td>C.A.T.S cell saver</td>
			<td>Fresenius Kabi</td>
			<td>ES0019</td>
			<td>Cell saver device used to wash donor blood</td>
		</tr>
		<tr>
			<td>Cardiac defibrillator</td>
			<td>Zoll</td>
			<td>M Series</td>
			<td>Cardiac defibrillator</td>
		</tr>
		<tr>
			<td>Castro needle holder</td>
			<td>V. Mueller</td>
			<td>CH8589</td>
			<td></td>
		</tr>
		<tr>
			<td>CG4 iStat cartridges</td>
			<td>Abbott</td>
			<td>03P85-25</td>
			<td>POC testing</td>
		</tr>
		<tr>
			<td>CG8 iStat cartridges</td>
			<td>Abbott</td>
			<td>03P88-25</td>
			<td>POC testing</td>
		</tr>
		<tr>
			<td>DeBakey forceps</td>
			<td>V. Mueller</td>
			<td>CH5902</td>
			<td></td>
		</tr>
		<tr>
			<td>Electrocautery disposable pencil</td>
			<td>Covidien</td>
			<td>E2450H</td>
			<td></td>
		</tr>
		<tr>
			<td>Gerald forceps</td>
			<td>V. Mueller</td>
			<td>NL1451</td>
			<td></td>
		</tr>
		<tr>
			<td>Hemotherm 400CE Dual Reservoir Cooler/Heater</td>
			<td>Cincinnati Sub-Zero</td>
			<td>86022</td>
			<td>Heater cooler used to regulate perfusion temperature on the ex vivo perfusion device</td>
		</tr>
		<tr>
			<td>iSTAT 1</td>
			<td>Abbott</td>
			<td>04P75-03</td>
			<td>POC testing device</td>
		</tr>
		<tr>
			<td>Kocher clamp</td>
			<td>V. Mueller</td>
			<td>SU2790</td>
			<td></td>
		</tr>
		<tr>
			<td>Large clip applier</td>
			<td>Sklar</td>
			<td>50-4300</td>
			<td></td>
		</tr>
		<tr>
			<td>Large clips</td>
			<td>Teleflex</td>
			<td>4200</td>
			<td></td>
		</tr>
		<tr>
			<td>Large soft pledgets</td>
			<td>Covidien</td>
			<td>8886867901</td>
			<td></td>
		</tr>
		<tr>
			<td>Medium clip applier</td>
			<td>Sklar</td>
			<td>50-4335</td>
			<td></td>
		</tr>
		<tr>
			<td>Medium clips</td>
			<td>Teleflex</td>
			<td>2200</td>
			<td></td>
		</tr>
		<tr>
			<td>Metzenbaum scissor</td>
			<td>V. Mueller</td>
			<td>CH2006-001</td>
			<td></td>
		</tr>
		<tr>
			<td>No. 10 scalpel blade</td>
			<td>Swann-Mortan</td>
			<td>301</td>
			<td>Used for skin incision</td>
		</tr>
		<tr>
			<td>No. 11 scalpel blade</td>
			<td>Kiato Plus</td>
			<td>18111</td>
			<td>Used for vascular incision</td>
		</tr>
		<tr>
			<td>OCS device with base</td>
			<td>TransMedics, Inc.</td>
			<td></td>
			<td>Ex vivo perfusion device</td>
		</tr>
		<tr>
			<td>OCS disposable</td>
			<td>TransMedics, Inc.</td>
			<td></td>
			<td>Ex vivo perfusion device insert with perfusion kits</td>
		</tr>
		<tr>
			<td>Pacing cable</td>
			<td>Remington Medical</td>
			<td>FL-601-97</td>
			<td></td>
		</tr>
		<tr>
			<td>Pediatric cardioplegia catheter (4Fr)</td>
			<td>Medtronic, Inc</td>
			<td>10218</td>
			<td>Used to deliver cardioplegia to the donor aortic root</td>
		</tr>
		<tr>
			<td>Pediatric Foley catheter</td>
			<td>Teleflex</td>
			<td>RSH170003080</td>
			<td>Placed pre-op to decompress the recipient&#39;s bladder</td>
		</tr>
		<tr>
			<td>Potts scissors</td>
			<td>V. Mueller</td>
			<td>CH13038</td>
			<td></td>
		</tr>
		<tr>
			<td>Pressure bag x2 (1,000 mL)</td>
			<td>Novaplus</td>
			<td>V4010H</td>
			<td>Used to deliver cardioplegia at a set pressure</td>
		</tr>
		<tr>
			<td>Satinsky clamp</td>
			<td>V. Mueller</td>
			<td>CH7305</td>
			<td>Vascular clamp used for creating anastomoses between donor heart and recipient vessels</td>
		</tr>
		<tr>
			<td>Scissors</td>
			<td>Felco</td>
			<td>FELCO 200A-50</td>
			<td>Used to perform sternotomy</td>
		</tr>
		<tr>
			<td>Small hard pledgets</td>
			<td>Covidien</td>
			<td>8886867701</td>
			<td></td>
		</tr>
		<tr>
			<td>Sternal retractor</td>
			<td>V. Mueller</td>
			<td>CH6950-007</td>
			<td></td>
		</tr>
		<tr>
			<td>Temporary cardiac pacing wires</td>
			<td>Ethicon, Inc.</td>
			<td>TPW32</td>
			<td></td>
		</tr>
		<tr>
			<td>Temporary dual chamber pacemaker</td>
			<td>Medtronic, Inc</td>
			<td>5388</td>
			<td>Cardiac pacing device</td>
		</tr>
		<tr>
			<td>Tourniquet kit</td>
			<td>Medtronic, Inc</td>
			<td>79005</td>
			<td>Rummel tourniquets</td>
		</tr>
		<tr>
			<td>Umbilical tape</td>
			<td>Covidien</td>
			<td>8886861903</td>
			<td></td>
		</tr>
		<tr>
			<td>Vessel loops</td>
			<td>Covidien</td>
			<td>31145686</td>
			<td></td>
		</tr>
	</tbody>
</table>

a porcine heterotopic heart transplantation protocol for delivery of therapeutics to a cardiac allograft

Cardiac transplantation is the gold standard treatment for end-stage heart failure. However, it remains limited by the number of available donor hearts and complications such as primary graft dysfunction and graft rejection. The recent clinical use of an ex vivo perfusion device in cardiac transplantation introduces a unique opportunity for treating cardiac allografts with therapeutic interventions to improve function and avoid deleterious recipient responses. Establishing a translational, large-animal model for therapeutic delivery to the entire allograft is essential for testing novel therapeutic approaches in cardiac transplantation. The porcine, heterotopic heart transplantation model in the intraabdominal position serves as an excellent model for assessing the effects of novel interventions and the immunopathology of graft rejection. This model additionally offers long-term survival for the pig, given that the graft is not required to maintain the recipient's circulation. The aim of this protocol is to provide a reproducible and robust approach for achieving ex vivo delivery of a therapeutic to the entire cardiac allograft prior to transplantation and provide technical details to perform a survival heterotopic transplant of the ex vivo perfused heart.

This group has successfully survived 9 pigs between 5 and 35 days following the protocol as presented here, depending on the study design. Out of 10 pigs that have undergone this protocol, only 1 died prematurely from surgical complications, yielding a 90% survival rate. Demonstrated in Figure 2 is a diagram of the configuration of a heterotopic heart transplanted in the intraabdominal position in a pig. When determining the site for anastomosis of the allograft, select a site that minimizes...

Watch this Scientific Journal Video about A Porcine Heterotopic Heart Transplantation Protocol for Delivery of Therapeutics to a Cardiac Allograft at JoVE.com

A Porcine Heterotopic Heart Transplantation Protocol for Delivery of Therapeutics to a Cardiac Allograft

We present a protocol for utilizing a normothermic ex vivo sanguinous perfusion system for the delivery of therapeutics to an entire cardiac allograft in a porcine heterotopic heart transplant model.

Cardiac transplantation is the gold standard treatment for end-stage heart failure. However, it remains limited by the number of available donor hearts ...

a-porcine-heterotopic-heart-transplantation-protocol-for-delivery

Research

JoVE Journal

Medicine

2.5K Views.  Duke University. We present a protocol for utilizing a normothermic ex vivo sanguinous perfusion system for the delivery of therapeutics to an entire cardiac allograft in a porcine heterotopic heart transplant model.

Video: A Porcine Heterotopic Heart Transplantation Protocol for Delivery of Therapeutics to a Cardiac Allograft

Murine Heterotopic Heart Transplant Technique

It is now over forty years since this technique was first reported by Corry, Wynn and Russell. Although it took some years for other labs to become proficient in and utilize this technique, it is now widely used by many laboratories around the world. A significant refinement to the original technique was developed and reported in 2001 by Niimi. Described here are the techniques that have evolved over more than a decade in the hands of three surgeons (Plenter, Grazia, Pietra) in our center. These techniques are now being passed on to a younger generation of surgeons and researchers.
Based largely on the Niimi experience, the procedures used have evolved in the fine details - details which we will endeavor to relate here in such a way that others may be able to use this very useful model. Like Niimi, we have found that a video aid to learning is a priceless resource for the beginner.

The manuscript describes the steps required to perform the heterotopic heart transplant in the mouse.

It is now over forty years since this technique was first reported by Corry, Wynn and Russell. Although it took some years for other labs to become ...

Transplantation of Pulmonary Valve Using a Mouse Model of Heterotopic Heart Transplantation

Tissue engineered heart valves, especially decellularized valves, are starting to gain momentum in clinical use of reconstructive surgery with mixed results. However, the cellular and molecular mechanisms of the neotissue development, valve thickening, and stenosis development are not researched extensively. To answer the above questions, we developed a murine heterotopic heart valve transplantation model. A heart valve was harvested from a valve donor mouse and transplanted to a heart donor mouse. The heart with a new valve was transplanted heterotopically to a recipient mouse. The transplanted heart showed its own heartbeat, independent of the recipient&#8217;s heartbeat. The blood flow was quantified using a high frequency ultrasound system with a pulsed wave Doppler. The flow through the implanted pulmonary valve showed forward flow with minimal regurgitation and the peak flow was close to 100 mm/sec. This murine model of heart valve transplantation is highly versatile, so it can be modified and adapted to provide different hemodynamic environments and/or can be used with various transgenic mice to study neotissue development in a tissue engineered heart valve.

In order to understand the cellular and molecular mechanisms underlying neotissue formation and stenosis development in tissue engineered heart valves, a murine model of heterotopic heart valve transplantation was developed. A pulmonary heart valve was transplanted to recipient using the heterotopic heart transplantation technique.

Tissue engineered heart valves, especially decellularized valves, are starting to gain momentum in clinical use of reconstructive surgery with mixed ...

Rat Heterotopic Abdominal Heart/Single-lung Transplantation in a Volume-loaded Configuration

Herein, we describe a novel technique for heterotopic abdominal heart-lung transplantation (HAHLT) in rats. The configuration of the transplant graft involves anastomosis of donor inferior vena cava (IVC) to recipient IVC, and donor ascending aorta (Ao) to recipient abdominal Ao. The right upper and middle lung lobes are preserved and function as conduits for blood flow from right heart to left heart.
There are several advantages to using this technique, and it lends itself to a broad range of applications. Because the graft is transplanted in a configuration that allows for dyamic volume-loading, cardiac function may be directly assessed in vivo. The use of pressure-volume conductance catheters permits characterization of load-dependent and load-independent hemodynamic parameters. The graft may be converted to a loaded configuration by applying a clamp to the recipient&#8217;s infra-hepatic IVC. We describe modified surgical techniques for both donor and recipient operations, and an ideal myocardial protection strategy. Depending on the experimental aim, this model may be adapted for use in both acute and chronic studies of graft function, immunologic status, and variable ventricular loading conditions. The conducting airways to the transplanted lung are preserved, and allow for acute lung re-ventilation. This facilitates analysis of the effects of the mixed venous and arterial blood providing coronary perfusion to the graft.
A limitation of this model is its technical complexity. There is a significant learning curve for new operators, who should ideally be mentored in the technique. A surgical training background is advantageous for those wishing to apply this model. Despite its complexity, we aim to present the model in a clear and easily applicable format. Because of the physiologic similarity of this model to orthotopic transplantation, and its broad range of study applications, the effort invested in learning the technique is likely to be worthwhile.

We describe a novel technique for heterotopic abdominal heart-lung transplantation (HAHLT) in rats. The transplant configuration results in a partially loaded graft circulation, allowing direct functional assessment. This model may be employed for acute or chronic studies of function and immunologic status of the transplanted graft.

Herein, we describe a novel technique for heterotopic abdominal heart-lung transplantation (HAHLT) in rats. The configuration of the transplant graft ...

Heterotopic Cervical Heart Transplantation in Mice

The heterotopic cervical heart transplantation in mice is a valuable tool in transplant and cardiovascular research. The cuff technique greatly simplifies this model by avoiding challenging suture anastomoses of small vessels thereby reducing warm ischemia time. In comparison to abdominal graft implantation the cervical model is less invasive and the implanted graft is easily accessible for further follow-up examinations. Anastomoses are performed by pulling the ascending aorta of the graft over the cuff with the recipient&#8217;s common carotid artery and by pulling the main pulmonary artery over the cuff with the external jugular vein. Selection of appropriate cuff size and complete mobilization of the vessels are important for successful revascularization. Ischemia-reperfusion (I/R) injury can be minimized by perfusing the graft with a cardioplegic solution and by hypothermia. In this article, we provide technical details for a simplified and improved cuff technique, which should allow surgeons with basic microsurgical skills to perform the procedure with a high success rate.

The cuff technique shortens and facilitates the model of heterotopic cervical heart transplantation in mice by avoiding technically challenging suture anastomoses of small vessels. The technical details shown in this video paper should allow researches to establish this model in their laboratories.

The heterotopic cervical heart transplantation in mice is a valuable tool in transplant and cardiovascular research. The cuff technique greatly simplifies ...

Heterotopic Renal Autotransplantation in a Porcine Model: A Step-by-Step Protocol

Kidney transplantation is the treatment of choice for patients suffering from end-stage renal disease. It offers better life expectancy and higher quality of life when compared to dialysis. Although the last few decades have seen major improvements in patient outcomes following kidney transplantation, the increasing shortage of available organs represents a severe problem worldwide. To expand the donor pool, marginal kidney grafts recovered from extended criteria donors (ECD) or donated after circulatory death (DCD) are now accepted for transplantation. To further improve the postoperative outcome of these marginal grafts, research must focus on new therapeutic approaches such as alternative preservation techniques, immunomodulation, gene transfer, and stem cell administration.
Experimental studies in animal models are the final step before newly developed techniques can be translated into clinical practice. Porcine kidney transplantation is an excellent model of human transplantation and allows investigation of novel approaches. The major advantage of the porcine model is its anatomical and physiological similarity to the human body, which facilitates the rapid translation of new findings to clinical trials. This article offers a surgical step-by-step protocol for an autotransplantation model and highlights key factors to ensure experimental success. Adequate pre- and postoperative housing, attentive anesthesia, and consistent surgical techniques result in favorable postoperative outcomes. Resection of the contralateral native kidney provides the opportunity to assess post-transplant graft function. The placement of venous and urinary catheters and the use of metabolic cages allow further detailed evaluation. For long-term follow-up studies and investigation of alternative graft preservation techniques, autotransplantation models are superior to allotransplantation models, as they avoid the confounding bias posed by rejection and immunosuppressive medication.

Porcine models of organ transplantation provide an important platform to study mechanisms of organ preservation. This article describes a heterotopic porcine renal autotransplantation model, which allows investigating new approaches to improve the outcome of transplantation using marginal kidney grafts.

Kidney transplantation is the treatment of choice for patients suffering from end-stage renal disease. It offers better life expectancy and higher quality ...

A Pre-Clinical Porcine Model of Orthotopic Heart Transplantation

Fifty-years following the first successful report, cardiac transplantation remains the gold-standard treatment for eligible patients with advanced heart failure. Multiple small-animal models of heart transplantation have been used to study the acute and long-term effects of novel therapies. However, few are tested and demonstrated success in clinical trials. It is of critical importance to evaluate new therapies in a clinically relevant large-animal model for efficient and reliable translation of basic studies&#39;&#160;findings. Here, we describe a pre-clinical large-animal (porcine) model of orthotopic heart transplantation that has been firmly established and previously used to investigate novel cardioprotective strategies. This procedure focuses on acute ischemia-reperfusion injury and is a reliable method to investigate novel interventions which have been tested and validated in smaller experimental models, such as the murine model. We demonstrate its usefulness in assessing cardiac performance during the early post-transplantation period and other potential possibilities enabled by the model.

Here, we describe a pre-clinical large-animal (porcine) model of orthotopic heart transplantation that has been firmly established and utilized to investigate novel cardioprotective strategies.

Fifty-years following the first successful report, cardiac transplantation remains the gold-standard treatment for eligible patients with advanced heart ...

A Simplified Model for Heterotopic Heart Valve Transplantation in Rodents

There is an urgent clinical need for heart valve replacements that can grow in children. Heart valve transplantation is proposed as a new type of transplant with the potential to deliver durable heart valves capable of somatic growth with no requirement for anticoagulation. However, the immunobiology of heart valve transplants remains unexplored, highlighting the need for animal models to study this new type of transplant. Previous rat models for heterotopic aortic valve transplantation into the abdominal aorta have been described, though they are technically challenging and costly. For addressing this challenge, a renal subcapsular transplant model was developed in rodents as a practical and more straightforward method for studying heart valve transplant immunobiology. In this model, a single aortic valve leaflet is harvested and inserted into the renal subcapsular space. The kidney is easily accessible, and the transplanted tissue is securely contained in a subcapsular space that is well vascularized and can accommodate a variety of tissue sizes. Furthermore, because a single rat can provide three donor aortic leaflets and a single kidney can provide multiple sites for transplanted tissue, fewer rats are required for a given study. Here, the transplantation technique is described, providing a significant step forward in studying the transplant immunology of heart valve transplantation.

This protocol describes a simple and efficient method for the transplantation of aortic valve leaflets under the renal capsule to allow for the study of alloreactivity of heart valves.

There is an urgent clinical need for heart valve replacements that can grow in children. Heart valve transplantation is proposed as a new type of ...

Left Lung Orthotopic Transplantation in a Juvenile Porcine Model for ESLP

Lung transplantation is the gold-standard treatment for end-stage lung disease, with over 4,600 lung transplantations performed worldwide annually. However, lung transplantation is limited by a shortage of available donor organs. As such, there is high waitlist mortality. Ex situ lung perfusion (ESLP) has increased donor lung utilization rates in some centers by 15%-20%. ESLP has been applied as a method to assess and recondition marginal donor lungs and has demonstrated acceptable short- and long-term outcomes following transplantation of extended criteria donor (ECD) lungs. Large animal (in vivo) transplantation models are required to validate ongoing in vitro research findings. Anatomic and physiologic differences between humans and pigs pose significant technical and anesthetic challenges. An easily reproducible transplant model would permit the&#160;in vivo&#160;validation of current ESLP strategies and the preclinical evaluation of various interventions designed to improve donor lung function. This protocol describes a porcine model of orthotopic left lung allotransplantation. This includes anesthetic and surgical techniques, a customized surgical checklist, troubleshooting, modifications, and the benefits and limitations of the approach.

This protocol describes a juvenile porcine model of orthotopic left lung allotransplantation designed for use with ESLP research. Focus is made on anesthetic and surgical techniques, as well as critical steps and troubleshooting.

Lung transplantation is the gold-standard treatment for end-stage lung disease, with over 4,600 lung transplantations performed worldwide annually. ...

A Modified Cuff Technique for Mouse Cervical Heterotopic Heart Transplantation Model

Cardiac allograft rejection limits the long-term survival of patients after heart transplantation. A mouse heart transplantation model is ideal for investigating the mechanism of cardiac allograft rejection in preclinical studies because of their high homology with human genes. This understanding would help develop unique approaches to improving patients&#39; long-term survival treated with cardiac allografts. In a mouse model, abdominal donor heart implantation is commonly performed with an end-to-end&#160;anastomosis to the recipient&#39;s aorta and inferior vena cava using stitches. In this model, the donor&#39;s heart is implanted by end-to-end anastomosis to the recipient&#39;s carotid artery and jugular vein by the modified-Cuff technique. The transplantation surgery is performed without stitching and thus may increase the survival of the recipient since there is no interference with the blood supply and venous reflux of the lower body. This mouse model would help investigate the mechanisms underlying the immunological and pathological (acute/chronic) rejection of cardiac allografts.

In the present protocol, a mouse heart transplantation model is used for investigating the mechanism of cardiac allograft rejection. In this heterotopic heart transplantation model, operation efficiency is improved, and the survival of cardiac grafts is ensured by a cervical end-to-end anastomosis of heart implantation using a modified Cuff technique.

Cardiac allograft rejection limits the long-term survival of patients after heart transplantation. A mouse heart transplantation model is ideal for ...

Delivery of Cardioactive Therapeutics in a Porcine Myocardial Infarction Model

Myocardial infarction is one of the leading causes of death and disability worldwide, and there is an urgent need for novel cardioprotective or regenerative strategies. An essential component of drug development is determining how a novel therapeutic is to be administered. Physiologically relevant large animal models are of critical importance in assessing the feasibility and efficacy of various therapeutic delivery strategies. Due to their similarities to humans in cardiovascular physiology, coronary vascular anatomy, and heart weight to body weight ratio, swine is one of the preferred species in the preclinical evaluation of new therapies for myocardial infarction. The present protocol describes three methods of administering cardioactive therapeutic agents in a porcine model. After percutaneously induced myocardial infarction, female landrace swine received treatment with novel agents through either: (1) thoracotomy and transepicardial injection, (2) catheter-based transendocardial injection, or (3) intravenous infusion via jugular vein osmotic minipump. The procedures employed for each technique are reproducible, resulting in reliable cardioactive drug delivery. These models can be easily adapted to suit individual study designs, and each of these delivery techniques can be used to investigate a variety of possible interventions. Therefore, these methods are a useful tool for translational scientists pursuing novel biological approaches in cardiac repair following myocardial infarction.

The present protocol describes three methods of administering cardioactive therapeutic agents in a porcine model. Female landrace swine received treatment through either: (1) thoracotomy and transepicardial injection, (2) catheter-based transendocardial injection, or (3) intravenous infusion via jugular vein osmotic minipump.