This research was funded on behalf of The Hospital Research Foundation.

<ol>
	<li>Chambers, D. 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=The+international+thoracic+organ+transplant+registry+of+the+international+society+for+heart+and+lung+transplantation:+Thirty-fifth+adult+lung+and+heart-lung+transplant+report-2018;+focus+theme:+Multiorgan+transplantation.">The international thoracic organ transplant registry of the international society for heart and lung transplantation: Thirty-fifth adult lung and heart-lung transplant report-2018; focus theme: Multiorgan transplantation.</a> The Journal of Heart and Lung Transplantation. 37 (10), 1169-1183 (2018).</li><li>Valapour, 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=OPTN/SRTR+2017+annual+data+report:+Lung.">OPTN/SRTR 2017 annual data report: Lung.</a> American Journal of Transplantation. 19, 404-484 (2019).</li><li>Chambers, D. 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=The+registry+of+the+international+society+for+heart+and+lung+transplantation:+Thirty-fourth+adult+lung+and+heart-lung+transplantation+report-2017;+focus+theme:+Allograft+ischemic+time.">The registry of the international society for heart and lung transplantation: Thirty-fourth adult lung and heart-lung transplantation report-2017; focus theme: Allograft ischemic time.</a> The Journal of Heart and Lung Transplantation. 36 (10), 1047-1059 (2017).</li><li>Klein, A. 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=Organ+donation+and+utilization+in+the+united+states,+1999-2008.">Organ donation and utilization in the united states, 1999-2008.</a> American Journal of Transplantation. 10 (4), 973-986 (2010).</li><li>Singh, E., 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=Sequence+of+refusals+for+donor+quality,+organ+utilization,+and+survival+after+lung+transplantation.">Sequence of refusals for donor quality, organ utilization, and survival after lung transplantation.</a> The Journal of Heart and Lung Transplantation. 38 (1), 35-42 (2019).</li><li>Bhorade, S. M., Vigneswaran, W., McCabe, M. A., Garrity, E. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Liberalization+of+donor+criteria+may+expand+the+donor+pool+without+adverse+consequence+in+lung+transplantation.">Liberalization of donor criteria may expand the donor pool without adverse consequence in lung transplantation.</a> The Journal of Heart and Lung Transplantation. 19 (12), 1199-1204 (2000).</li><li>Snell, G. I., Griffiths, A., Levvey, B. J., Oto, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Availability+of+lungs+for+transplantation:+Exploring+the+real+potential+of+the+donor+pool.">Availability of lungs for transplantation: Exploring the real potential of the donor pool.</a> The Journal of Heart and Lung Transplantation. 27 (6), 662-667 (2008).</li><li>Cypel, 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+lung+perfusion+in+clinical+lung+transplantation.">Normothermic ex vivo lung perfusion in clinical lung transplantation.</a> The New England Journal of Medicine. 364 (15), 1431-1440 (2011).</li><li>Wallinder, 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=Early+results+in+transplantation+of+initially+rejected+donor+lungs+after+ex+vivo+lung+perfusion:+A+case-control+study.">Early results in transplantation of initially rejected donor lungs after ex vivo lung perfusion: A case-control study.</a> European Journal of Cardio-Thoracic Surgery. 45 (1), 40-45 (2014).</li><li>Cypel, 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=Experience+with+the+first+50+ex+vivo+lung+perfusions+in+clinical+transplantation.">Experience with the first 50 ex vivo lung perfusions in clinical transplantation.</a> The Journal of Thoracic and Cardiovascular Surgery. 144 (1), 1200-1206 (2012).</li><li>Buchko, M. T., 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=Total+parenteral+nutrition+in+ex+vivo+lung+perfusion:+Addressing+metabolism+improves+both+inflammation+and+oxygenation.">Total parenteral nutrition in ex vivo lung perfusion: Addressing metabolism improves both inflammation and oxygenation.</a> American Journal of Transplantation. 19 (12), 3390-3397 (2019).</li><li>Andreasson, A. S. I., 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=Profiling+inflammation+and+tissue+injury+markers+in+perfusate+and+bronchoalveolar+lavage+fluid+during+human+ex+vivo+lung+perfusion.">Profiling inflammation and tissue injury markers in perfusate and bronchoalveolar lavage fluid during human ex vivo lung perfusion.</a> European Journal of Cardio-Thoracic Surgery. 51 (3), 577-586 (2017).</li><li>Sadaria, M. 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=Cytokine+expression+profile+in+human+lungs+undergoing+normothermic+ex-vivo+lung+perfusion.">Cytokine expression profile in human lungs undergoing normothermic ex-vivo lung perfusion.</a> The Annals of Thoracic Surgery. 92 (2), 478-484 (2011).</li><li>Ricard, J. D., Dreyfuss, D., Saumon, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ventilator-induced+lung+injury.">Ventilator-induced lung injury.</a> European Respiratory Journal. 42, 2-9 (2003).</li><li>Aboelnazar, N. 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=Negative+pressure+ventilation+decreases+inflammation+and+lung+edema+during+normothermic+ex-vivo+lung+perfusion.">Negative pressure ventilation decreases inflammation and lung edema during normothermic ex-vivo lung perfusion.</a> The Journal of Heart and Lung Transplantation. 37 (4), 520-530 (2018).</li><li>Lai-Fook, S. J., Rodarte, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pleural+pressure+distribution+and+its+relationship+to+lung+volume+and+interstitial+pressure.">Pleural pressure distribution and its relationship to lung volume and interstitial pressure.</a> Journal of Applied Physiology. 70 (3), 967-978 (1991).</li><li>Buchko, M. T., 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=Clinical+transplantation+using+negative+pressure+ventilation+ex+situ+lung+perfusion+with+extended+criteria+donor+lungs.">Clinical transplantation using negative pressure ventilation ex situ lung perfusion with extended criteria donor lungs.</a> Nature Communications. 11 (1), 5765 (2020).</li><li>Buchko, M. T., 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+low-cost+perfusate+alternative+for+ex+vivo+perfusion.">A low-cost perfusate alternative for ex vivo perfusion.</a> Transplantation Proceedings. 52 (10), 2941-2946 (2020).</li><li>Forgie, K. 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=Left+lung+orthotopic+transplantation+in+a+juvenile+porcine+model+for+ESLP.">Left lung orthotopic transplantation in a juvenile porcine model for ESLP.</a> The Journal of Visualized Experiments. , (2021).</li></ol>

DHF holds patents on ex situ organ perfusion technology and methods. DHF and JN are founders and major shareholders of Tevosol, Inc.

There are several critical surgical steps along with troubleshooting needed to ensure a successful ESLP run. Juvenile porcine lungs are extremely delicate compared to adult human lungs, so the procuring surgeon must be cautious when handling porcine lungs. It is critical to attempt a &#34;no-touch&#34; technique to avoid causing trauma and atelectasis when dissecting out the lungs. &#34;No-touch&#34; means using the bare minimum amount of manual manipulation of the lungs during procurement. Recruitment maneuvers while on...

Lung transplantation (LTx) remains the standard of care for end-stage lung disease1; however, LTx has significant limitations including inadequate donor organ utilization2 and a waitlist mortality of 40%3, which is higher than any other solid organ transplant4,5. Donor organ utilization rates are low (20-30%) due to organ quality concerns. Excessive geographic transportation distance compounded by stringent donor organ acceptance criteria exacerbates these quality concerns. LTx also trails other solid organ transplants in terms of long-term graft and patient outcomes2. Primary graft dysfunction (PGD), most often caused by ischemic reperfusion injury (IRI), represents the leading cause of 30-day mortality and morbidity post-LTx and increases the risk for chronic graft dysfunction6,7. Efforts to decrease IRI and extend safe transport times are paramount to improve patient outcomes.
Ex situ lung perfusion (ESLP) is an innovative technology that has shown promise in attenuating these limitations. ESLP facilitates the preservation, assessment, and reconditioning of donor lungs before transplantation. It has exhibited satisfactory short- and long-term outcomes following transplantation of extended criteria donor (ECD) lungs, contributing to an increase in the number of suitable donor lungs for LTx, with organ utilization rates increasing by 20% in some centres8,9,10. Compared to the current clinical standard for LTx, cold static preservation (CSP), ESLP offers several advantages: organ preservation time is not limited to 6 h, evaluation of organ function is possible before implantation, and due to continuous organ perfusion, modifications can be made to the perfusate that optimizes organ function11.
The vast majority of current ESLP devices designed for human use utilize positive pressure ventilation (PPV); however, recent literature has indicated that this ventilation strategy is inferior to negative pressure ventilation (NPV) ESLP, with PPV inducing more significant ventilator-induced lung injury12,13,14,15. In both human and porcine lungs, NPV-ESLP exhibits superior organ function when compared to positive pressure ex situ lung perfusion (PPV-ESLP) across various physiological domains, including pro-inflammatory cytokine production, pulmonary edema, and bullae formation15. The homogenous distribution of intrathoracic pressure across the entire lung surface in NPV-ESLP has been suggested as a significant factor underlying this advantage15,16. In addition to its pre-clinical benefits, the clinical safety and feasibility of NPV-ESLP have been demonstrated in a recent clinical trial17. Utilizing a novel NPV-ESLP device, twelve extended criteria donor human lungs were successfully preserved, evaluated, and subsequently transplanted with 100% 30-day and 1-year survival.
The objective of the present manuscript is to demonstrate a working protocol of our lab&#39;s NPV-ESLP device using juvenile porcine lungs under normothermic conditions for 12 h of duration. The surgical retrieval is covered in detail, and our custom software platform&#39;s initiation, management, and termination are also described. The strategy for tissue collection and the management of the samples is also explained.

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			<td>0 ETHIBOND Green 1 x 36&#34; Endo Loop 0</td>
			<td>ETHICON</td>
			<td>D8573</td>
			<td></td>
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		<tr>
			<td>2-0 SILK Black 12&#34; x 18&#34; Strands</td>
			<td>ETHICON</td>
			<td>SA77G</td>
			<td></td>
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		<tr>
			<td>ABL 800 FLEX Blood Gas Analyzer</td>
			<td>Radiometer</td>
			<td>989-963</td>
			<td></td>
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		<tr>
			<td>Adult-Pediatric Electrostatic Filter HME - Small</td>
			<td>Covidien</td>
			<td>352/5877</td>
			<td></td>
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		<tr>
			<td>Arterial Filter</td>
			<td>SORIN GROUP</td>
			<td>01706/03</td>
			<td></td>
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		<tr>
			<td>Backhaus Towel Clamp</td>
			<td>Pilling</td>
			<td>454300</td>
			<td></td>
		</tr>
		<tr>
			<td>Biomedicus Pump</td>
			<td>Maquet</td>
			<td>BPX-80</td>
			<td></td>
		</tr>
		<tr>
			<td>Cable Ties &#8211; White 12&#8221;</td>
			<td>HUASU International</td>
			<td>HS4830001</td>
			<td></td>
		</tr>
		<tr>
			<td>Calcium Chloride</td>
			<td>Fisher Scientific</td>
			<td>C69-500G</td>
			<td></td>
		</tr>
		<tr>
			<td>Cooley Sternal Retractor</td>
			<td>Pilling</td>
			<td>341162</td>
			<td></td>
		</tr>
		<tr>
			<td>CUSHING Gutschdressing Forceps</td>
			<td>Pilling</td>
			<td>466200</td>
			<td></td>
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		<tr>
			<td>D-glucose</td>
			<td>Sigma-Aldrich</td>
			<td>G5767-500G</td>
			<td></td>
		</tr>
		<tr>
			<td>Deep Deaver Retractor</td>
			<td>Pilling</td>
			<td>481826</td>
			<td></td>
		</tr>
		<tr>
			<td>Debakey Straight Vascular Tissue Forceps</td>
			<td>Pilling</td>
			<td>351808</td>
			<td></td>
		</tr>
		<tr>
			<td>Debakey-Metzenbaum Dissecting</td>
			<td>Pilling</td>
			<td>342202</td>
			<td></td>
		</tr>
		<tr>
			<td>Scissors</td>
			<td>Pilling</td>
			<td>342202</td>
			<td></td>
		</tr>
		<tr>
			<td>Endotracheal Tube 9.0mm CUFD</td>
			<td>Mallinckrodt</td>
			<td>9590E</td>
			<td>Cuff removed for ESLP apparatus</td>
		</tr>
		<tr>
			<td>Flow Transducer</td>
			<td>BIO-PROBE</td>
			<td>TX 40</td>
			<td></td>
		</tr>
		<tr>
			<td>Human Albumin Serum</td>
			<td>Grifols Therapeutics</td>
			<td>2223708</td>
			<td></td>
		</tr>
		<tr>
			<td>Infusion Pump</td>
			<td>Baxter</td>
			<td>AS50</td>
			<td></td>
		</tr>
		<tr>
			<td>Inspire 7 M Hollow Fiber Membrane Oxygenator</td>
			<td>SORIN GROUP</td>
			<td>K190690</td>
			<td></td>
		</tr>
		<tr>
			<td>Intercept Tubing 1/4&#34; x 1/16&#34; x 8&#39;</td>
			<td>Medtronic</td>
			<td>3108</td>
			<td></td>
		</tr>
		<tr>
			<td>Intercept Tubing 3/8&#34; x 3/32&#34; x 6&#39;</td>
			<td>Medtronic</td>
			<td>3506</td>
			<td></td>
		</tr>
		<tr>
			<td>Intercept Tubing Connector 3/8&#34; x 1/2&#34;</td>
			<td>Medtronic</td>
			<td>6013</td>
			<td></td>
		</tr>
		<tr>
			<td>MAYO Dissecting Scissors</td>
			<td>Pilling</td>
			<td>460420</td>
			<td></td>
		</tr>
		<tr>
			<td>Medical Carbon Dioxide Tank</td>
			<td>Praxair</td>
			<td>5823115</td>
			<td></td>
		</tr>
		<tr>
			<td>Medical Nitrogen Tank</td>
			<td>Praxair</td>
			<td>NI M-K</td>
			<td></td>
		</tr>
		<tr>
			<td>Medical Oxygen Tank</td>
			<td>Praxair</td>
			<td>2014408</td>
			<td></td>
		</tr>
		<tr>
			<td>Organ Chamber</td>
			<td>Tevosol</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>PlasmaLyte A</td>
			<td>Baxter</td>
			<td>TB2544</td>
			<td></td>
		</tr>
		<tr>
			<td>Poole Suction Tube</td>
			<td>Pilling</td>
			<td>162212</td>
			<td></td>
		</tr>
		<tr>
			<td>Potassium Phosphate</td>
			<td>Fischer Scientific</td>
			<td>P285-500G</td>
			<td></td>
		</tr>
		<tr>
			<td>Scale</td>
			<td>TANITA</td>
			<td>KD4063611</td>
			<td></td>
		</tr>
		<tr>
			<td>Silicon Support Membrane</td>
			<td>Tevosol</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Bicarbonate</td>
			<td>Sigma-Aldrich</td>
			<td>792519-1KG</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Chloride 0.9%</td>
			<td>Baxter</td>
			<td>JB1324</td>
			<td></td>
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			<td>Sorin XTRA Cell Saver</td>
			<td>SORIN GROUP</td>
			<td>75221</td>
			<td></td>
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			<td>Sternal Saw</td>
			<td>Stryker</td>
			<td>6207</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical Electrocautery Device</td>
			<td>Kls Martin</td>
			<td>ME411</td>
			<td></td>
		</tr>
		<tr>
			<td>Temperature Sensor probe</td>
			<td>Omniacell Tertia Srl</td>
			<td>1777288F</td>
			<td></td>
		</tr>
		<tr>
			<td>THAM Buffer</td>
			<td>Thermo Fisher Scientific</td>
			<td>15504020</td>
			<td>made from UltraPureTM Tris</td>
		</tr>
		<tr>
			<td>TruWave Pressure Transducer</td>
			<td>Edwards</td>
			<td>VSYPX272</td>
			<td></td>
		</tr>
		<tr>
			<td>Two-Lumen Central Venous Catheter 7fr</td>
			<td>Arrowg+ard</td>
			<td>CS-12702-E</td>
			<td></td>
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		<tr>
			<td>Vorse Tubing Clamp</td>
			<td>Pilling</td>
			<td>351377</td>
			<td></td>
		</tr>
		<tr>
			<td>Willauer-Deaver Retractor</td>
			<td>Pilling</td>
			<td>341720</td>
			<td></td>
		</tr>
		<tr>
			<td>Yankauer Suction Tube</td>
			<td>Pilling</td>
			<td>162300</td>
			<td></td>
		</tr>
	</tbody>
</table>

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.

At the beginning of lung perfusion and ventilation (preservation mode), the lungs will generally have a low pulmonary artery pressure (&#60; 10 mmHg) and low dynamic compliance (&#60; 10 mL/mmHg) as the perfusate warms to normothermia. Yorkshire pigs weighing 35-50 kg typically results in lungs weighing 350-500 g. During the first hour of NPV-ESLP, the measured expiratory tidal volumes (TVe) are 0-2 mL/kg, and the inspiratory tidal volumes (TVi) are 100-200 mL. TVe generally reaches 4-6 mL/kg within 3-6 h, and after that...

Watch this Scientific Journal Video about Normothermic Negative Pressure Ventilation Ex Situ Lung Perfusion: Evaluation of Lung Function and Metabolism at JoVE.com

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.

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 ...

normothermic-negative-pressure-ventilation-ex-situ-lung-perfusion

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2.0K Views.  University of Alberta. 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.

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

Pressure Controlled Ventilation to Induce Acute Lung Injury in Mice

Murine models are extensively used to investigate acute injuries of different organs systems (1-34). Acute lung injury (ALI), which occurs with prolonged mechanical ventilation, contributes to morbidity and mortality of critical illness, and studies on novel genetic or pharmacological targets are areas of intense investigation (1-3, 5, 8, 26, 30, 33-36). ALI is defined by the acute onset of the disease, which leads to non-cardiac pulmonary edema and subsequent impairment of pulmonary gas exchange (36). We have developed a murine model of ALI by using a pressure-controlled ventilation to induce ventilator-induced lung injury (2). For this purpose, C57BL/6 mice are anesthetized and a tracheotomy is performed followed by induction of ALI via mechanical ventilation. Mice are ventilated in a pressure-controlled setting with an inspiratory peak pressure of 45 mbar over 1 - 3 hours. As outcome parameters, pulmonary edema (wet-to-dry ratio), bronchoalveolar fluid albumin content, bronchoalveolar fluid and pulmonary tissue myeloperoxidase content and pulmonary gas exchange are assessed (2). Using this technique we could show that it sufficiently induces acute lung inflammation and can distinguish between different treatment groups or genotypes (1-3, 5). Therefore this technique may be helpful for researchers who pursue molecular mechanisms involved in ALI using a genetic approach in mice with gene-targeted deletion.

A murine model for ventilator induced lung injury is an important tool to study an acute lung injury in vivo. Here, we report an easy applicable in situ model for acute lung injury using high-pressure mechanical ventilation to induce acute failure of the lung.

Murine models are extensively used to investigate acute injuries of different organs systems (1-34). Acute lung injury (ALI), which occurs with prolonged ...

Method of Isolated Ex Vivo Lung Perfusion in a Rat Model: Lessons Learned from Developing a Rat EVLP Program

The number of acceptable donor lungs available for lung transplantation is severely limited due to poor quality. Ex-Vivo Lung Perfusion (EVLP) has allowed lung transplantation in humans to become more readily available by enabling the ability to assess organs and expand the donor pool. As this technology expands and improves, the ability to potentially evaluate and improve the quality of substandard lungs prior to transplant is a critical need. In order to more rigorously evaluate these approaches, a reproducible animal model needs to be established that would allow for testing of improved techniques and management of the donated lungs as well as to the lung-transplant recipient. In addition, an EVLP animal model of associated pathologies, e.g., ventilation induced lung injury (VILI), would provide a novel method to evaluate treatments for these pathologies. Here, we describe the development of a rat EVLP lung program and refinements to this method that allow for a reproducible model for future expansion. We also describe the application of this EVLP system to model VILI in rat lungs. The goal is to provide the research community with key information and &#8220;pearls of wisdom&#8221;/techniques that arose from trial and error and are critical to establishing an EVLP system that is robust and reproducible.

Method of Isolated Ex Vivo Lung Perfusion in a Rat Model: Lessons Learned from Developing a Rat EVLP Program

Ex-Vivo Lung Perfusion (EVLP) has allowed lung transplantation in humans to become more readily available by enabling the ability to assess organs and expand the donor pool. Here, we describe the development of a rat EVLP program and refinements that allow for a reproducible model for future expansion.

The number of acceptable donor lungs available for lung transplantation is severely limited due to poor quality. Ex-Vivo Lung Perfusion (EVLP) has allowed ...

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 ...

Lung Fixation under Constant Pressure for Evaluation of Emphysema in Mice

Emphysema is a significant feature of chronic obstructive pulmonary disease (COPD). Studies involving an emphysematous mouse model require optimal lung fixation to produce reliable histological specimens of the lung. Due to the nature of the lung&rsquo;s structural composition, which consists largely of air and tissue, there is a risk that it collapses or deflates during the fixation process. Various lung fixation methods exist, each of which has its own advantages and disadvantages. The lung fixation method presented here utilizes constant pressure to enable optimal tissue evaluation for studies using an emphysematous mouse lung model. The main advantage is that it can fix many lungs with the same condition at one time. Lung specimens are obtained from chronic cigarette smoke-exposed mice. Lung fixation is performed using specialized equipment that enables the production of constant pressure. This constant pressure maintains the lung in a reasonably inflated state. Thus, this method generates a histological specimen of the lung that is suitable to evaluate cigarette smoke-induced mild emphysema.

Presented here is a useful protocol for lung fixation that creates a stable condition for histological evaluate of lung specimens from a mouse model of emphysema. The main advantage of this model is that it can fix many lungs with the same constant pressure without lung collapse or deflation.

Emphysema is a significant feature of chronic obstructive pulmonary disease (COPD). Studies involving an emphysematous mouse model require optimal lung ...

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 ...

Lung Rapid Recovery Procurement Combined with Abdominal Normothermic Regional Perfusion in Controlled Donation after Circulatory Death

Controlled donation after circulatory death (cDCD) has contributed to increasing donor numbers all over the world. Experiences published in the last years confirm that the outcomes after lung transplantation from cDCD are similar to those from brain death donors; however, the utilization of lungs from asystole donors remains low. Several reasons may be involved: different legal frameworks among countries and centers with different premortem interventions, inadequate lung donor care before procurement, or even poor experience with cDCD procedures and protocols.
Initially, the rapid recovery technique was commonly employed for the procurement of thoracic and abdominal organs in cDCD, but, in the last decade, abdominal normothermic regional perfusion (ANRP) with extracorporeal membrane oxygenation devices has become a useful method to restore blood flow to abdominal organs, allowing their quality improvement and their functional assessment prior to transplantation. This makes the donation procedure more complex and generates doubts about injury to the grafts due to dual temperature.
The aim of this article is to describe a protocol based on a single center experience with Maastricht III donors combining lung cooling rapid recovery in the thorax and abdominal normothermic regional perfusion. Tips and tricks focused on premortem interventions and lung procurement procedure techniques are explained. This may help to minimize the reluctance among professionals to use this combined technique and encourage other donor centers to use it, despite the increased complexity of the procedure.

The protocol combines a lung cooling rapid recovery technique with abdominal normothermic regional perfusion for abdominal graft procurement in controlled asystole donors, which is a safe and useful method to expand the donor pool.

Controlled donation after circulatory death (cDCD) has contributed to increasing donor numbers all over the world. Experiences published in the last years ...

A Standardized Workflow for Hyperpolarized 129Xe MRI to Study Pulmonary Function

Acquiring Hyperpolarized 129Xe Magnetic Resonance Images of Lung Ventilation

Hyperpolarized 129Xe MRI comprises a unique array of structural and functional lung imaging techniques. Technique standardization across sites is increasingly important given the recent FDA approval of 129Xe as an MR contrast agent and as interest in 129Xe MRI increases among research and clinical institutions. Members of the 129Xe MRI Clinical Trials Consortium (Xe MRI CTC) have agreed upon best practices for each of the key aspects of the 129Xe MRI workflow, and these recommendations are summarized in a recent publication. This work provides practical information to develop an end-to-end workflow for collecting 129Xe MR images of lung ventilation according to the Xe MRI CTC recommendations. Preparation and administration of 129Xe for MR studies will be discussed and demonstrated, with specific topics including choice of appropriate gas volumes for entire studies and for individual MR scans, preparation&#160;and delivery of individual 129Xe doses, and best practices for monitoring subject safety and 129Xe tolerability during studies. Key MR technical considerations will also be covered, including pulse sequence types and optimized parameters, calibration of 129Xe flip angle and center frequency, and 129Xe MRI ventilation image analysis.

Author Spotlight: Standardization and Best Practices for Advancing Lung Imaging Using 129Xe MRI

Hyperpolarized 129Xe magnetic resonance imaging (MRI) is a method for studying regionally resolved aspects of pulmonary function. This work presents an end-to-end standardized workflow for hyperpolarized 129Xe MRI of lung ventilation, with specific attention to pulse sequence design, 129Xe dose preparation, scan workflow, and best practices for subject safety monitoring.

Hyperpolarized 129Xe MRI comprises a unique array of structural and functional lung imaging techniques. Technique standardization across sites is ...

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.

Lung transplantation is hampered by the lack of suitable donors. Previously, donors that were thought to be marginal or inadequate were discarded. ...

Advanced Lung Imaging for Disease Detection and Monitoring

Phase-Resolved Functional Lung MRI for Pulmonary Ventilation and Perfusion (V/Q) Assessment

Fourier decomposition is a contrast agent-free 1H MRI method for lung perfusion (Q) and ventilation (V) assessment. After image registration, the time series of each voxel is analyzed with regard to the cardiac and breathing frequency components.
Using a standard 2D spoiled gradient-echo sequence with a temporal resolution of ~300 ms, an image-sorting algorithm was developed to produce phase-resolved functional lung imaging (PREFUL) with an increased temporal resolution. Thus, it is feasible to evaluate regional flow volume loops (FVL) during tidal volume breathing and depict the propagation of the pulse wave during the cardiac cycle. This method can be applied at 1.5T or 3T with standard MR hardware without the necessity for sequence programming, as the described protocol can be implemented with the default SPGRE sequence on most systems.
PREFUL ventilation MRI has been validated using 129Xe and 19F gas imaging with good regional agreement. Perfusion-weighted PREFUL MRI has been validated using SPECT as well as dynamic contrast enhanced (DCE) MRI. PREFUL has been tested in a dual center dual vendor setting and is currently applied in several ongoing multicenter trials. Furthermore, it is feasible across a range of field strengths (0.55T-3T) and different age groups, including newborns.
Quantitative V/Q PREFUL MRI has been used in patients with cystic fibrosis, chronic obstructive pulmonary disease, chronic thromboembolic pulmonary hypertension, and corona virus disease-2019 to quantify disease and monitor treatment change after therapy. Furthermore, PREFUL V/Q imaging has been shown to predict transplant loss due to chronic lung allograft dysfunction in patients after lung transplantation. In summary, PREFUL MRI is a validated technique for quantitative ventilation and pulmonary pulse wave/perfusion imaging for regional pulmonary disease detection, quantification, and treatment monitoring with potential added value to the current clinical routine.

Author Spotlight: Enhancing Diagnostic Strategies and Biomarker Development for Comprehensive Lung Function Analysis

Here, we describe the implementation of phase-resolved functional lung MRI as a contrast-agent-free proton MR technique for the assessment of pulmonary ventilation and perfusion dynamics. Validated and applicable across different field strengths and age groups, it could enhance clinical decision-making in the future by aiding in disease quantification and therapy monitoring.

Fourier decomposition is a contrast agent-free 1H MRI method for lung perfusion (Q) and ventilation (V) assessment. After image registration, the time ...