This project was supported by KFO 311 Grant from Deutsche Forschungsgemeinschaft.

Experiments were performed on male C57BL/6 mice, aged 12 weeks. This study was conducted in compliance with guidelines of the German Animal Law under Protocol TSA 16/2250.
1. Materials Preparation
NOTE: All steps are performed under clean, non-sterile conditions.&#160;Sterile conditions would be required if animal is to be survived postoperatively.
<ol>
	<li>Introduce 3 fenestrations into a 2-Fr polyurethane tube using a surgical blade under a microscope with 16X ...

<ol>
	<li>Hill, J. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prolonged+Extracorporeal+Oxygenation+for+Acute+Post-Traumatic+Respiratory+Failure+(Shock-Lung+Syndrome).">Prolonged Extracorporeal Oxygenation for Acute Post-Traumatic Respiratory Failure (Shock-Lung Syndrome).</a> New England Journal of Medicine. 286 (12), 629-634 (1972).</li><li>Noah, M. 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=Referral+to+an+Extracorporeal+Membrane+Oxygenation+Center+and+Mortality+Among+Patients+With+Severe+2009+Influenza+A(H1N1).">Referral to an Extracorporeal Membrane Oxygenation Center and Mortality Among Patients With Severe 2009 Influenza A(H1N1).</a> Journal of the American Medical Association. 306 (15), 1659 (2011).</li><li>Maslach-Hubbard, A., Bratton, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracorporeal+membrane+oxygenation+for+pediatric+respiratory+failure:+History,+development+and+current+status.">Extracorporeal membrane oxygenation for pediatric respiratory failure: History, development and current status.</a> World Journal of Critical. Care Medicine. 2 (4), 29-39 (2013).</li><li>Langer, 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="Awake"+extracorporeal+membrane+oxygenation+(ECMO):+pathophysiology,+technical+considerations,+and+clinical+pioneering.">"Awake" extracorporeal membrane oxygenation (ECMO): pathophysiology, technical considerations, and clinical pioneering.</a> Critical Care. 20 (1), 150 (2016).</li><li>Esper, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracorporeal+Membrane+Oxygenation.">Extracorporeal Membrane Oxygenation.</a> Advances in Anesthesia. 35 (1), 119-143 (2017).</li><li>Millar, J. E., Fanning, J. P., McDonald, C. I., McAuley, D. F., Fraser, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+inflammatory+response+to+extracorporeal+membrane+oxygenation+(ECMO):+a+review+of+the+pathophysiology.">The inflammatory response to extracorporeal membrane oxygenation (ECMO): a review of the pathophysiology.</a> Critical Care. 20 (1), 387 (2016).</li><li>Lubnow, 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=Technical+complications+during+veno-venous+extracorporeal+membrane+oxygenation+and+their+relevance+predicting+a+system-exchange--retrospective+analysis+of+265+cases.">Technical complications during veno-venous extracorporeal membrane oxygenation and their relevance predicting a system-exchange--retrospective analysis of 265 cases.</a> Public Library of Science One. 9 (12), e112316 (2014).</li><li>Passmore, 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=Inflammation+and+lung+injury+in+an+ovine+model+of+extracorporeal+membrane+oxygenation+support.">Inflammation and lung injury in an ovine model of extracorporeal membrane oxygenation support.</a> American Journal of Physiology - Lung Cellular and Molecular Physiology. 311 (6), L1202-L1212 (2016).</li><li>Vaquer, S., de Haro, C., Peruga, P., Oliva, J. C., Artigas, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systematic+review+and+meta-analysis+of+complications+and+mortality+of+veno-venous+extracorporeal+membrane+oxygenation+for+refractory+acute+respiratory+distress+syndrome.">Systematic review and meta-analysis of complications and mortality of veno-venous extracorporeal membrane oxygenation for refractory acute respiratory distress syndrome.</a> Annals of Intensive Care. 7 (1), 51 (2017).</li><li>Houser, S. 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=Animal+Models+of+Heart+Failure+A+Scientific+Statement+From+the+American+Heart+Association.">Animal Models of Heart Failure A Scientific Statement From the American Heart Association.</a> Circulation Research. 111 (1), 131-150 (2012).</li><li>Russell, J. C., Proctor, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Small+animal+models+of+cardiovascular+disease:+tools+for+the+study+of+the+roles+of+metabolic+syndrome,+dyslipidemia,+and+atherosclerosis.">Small animal models of cardiovascular disease: tools for the study of the roles of metabolic syndrome, dyslipidemia, and atherosclerosis.</a> Cardiovascular Pathology. 15 (6), 318-330 (2006).</li><li>Madrahimov, N., 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=Novel+mouse+model+of+cardiopulmonary+bypass.">Novel mouse model of cardiopulmonary bypass.</a> European Journal of Cardio-thoracic Surgery. 53 (1), 186-193 (2017).</li><li>Madrahimov, N., 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=Cardiopulmonary+Bypass+in+a+Mouse+Model:+A+Novel+Approach.">Cardiopulmonary Bypass in a Mouse Model: A Novel Approach.</a> J. Journal of Visualized Experiments. (127), (2017).</li></ol>

The authors have nothing to disclose.

Previously, we described a successful model of CPB in a mouse12,13. To implement such a model for acute or end-stage lung disorders we developed an easy-to-use veno-venous ECMO circuit for mice. Different to the CPB model, veno-venous ECMO does not require complicated surgical procedures such as sternotomy and clamping of the aorta, thus reducing the risk of wound bleeding in a fully heparinized animal. To avoid embolization of the oxygenator with blood clots, 2....

Extracorporeal membrane oxygenation (ECMO) is a temporary life support system that takes over functions of the lungs and heart to allow adequate gas exchange and perfusion. Hill et al1 described the first use of ECMO in patients in 1972; however, it only became widely used after its successful application during the H1N1 influenza pandemic in 20092. Today, ECMO is routinely used as a lifesaving procedure in end-stage heart and lung diseases3. Veno-venous ECMO is increasingly employed as an alternative to invasive mechanical ventilation in awake, non-intubated, spontaneously breathing patients with refractory respiratory failure4.
Despite its widespread adoption, diverse complications have been reported for ECMO5,6,7. Complications that can be experienced by patients on ECMO include bleeding, thrombosis, sepsis, thrombocytopenia, device-related malfunctions, and air embolism. Moreover, a systemic inflammatory response syndrome (SIRS) resulting in multi-organ damage is well-described both clinically and in experimental studies8,9. Neurological complications such as brain infarction are also frequently reported in patients undergoing long-term ECMO therapy. To confuse matters, it is often difficult to distinguish whether complications are caused by ECMO itself or arise from the underlying disorders accompanying acute and end-stage diseases.
To specifically study the effects of ECMO on a healthy organism, a reliable experimental animal model must be established. There are very few reports on performance of ECMO on small animals and are all limited to rats. To date, no mouse model of ECMO has been described in the literature. Due to the availability of a large number of genetically modified mouse strains, establishment of a mouse ECMO model would allow further investigation of the molecular mechanisms involved in ECMO-related complications10,11.
Based on our previously described murine model of cardiopulmonary bypass (CPB)12, we have developed a stable method of veno-venous ECMO in non-intubated, spontaneously breathing mice. The ECMO circuit (Figure 1), containing outflow and inflow cannulas, a peristaltic pump, oxygenator, and air-trapping reservoir, is similar to our previously described model of murine CPB12 with the exception of having a smaller priming volume (0.5 mL). This protocol demonstrates the detailed techniques, physiological monitoring, and blood gas analysis involved in a successful ECMO procedure.

<table>
	<tbody>
		<tr>
			<td>Sterofundin</td>
			<td>B.Braun Petzold GmbH</td>
			<td>PZN:8609189</td>
			<td>in 1:1 with Tetraspan</td>
		</tr>
		<tr>
			<td>Tetraspan 6% Solution</td>
			<td>B. Braun Melsungen AG</td>
			<td>PZN: 05565416</td>
			<td>in 1:1 with Sterofundin</td>
		</tr>
		<tr>
			<td>Heparin Natrium 25.000</td>
			<td>Ratiopharm GmbH</td>
			<td>PZN: 3029843</td>
			<td>2,5 IU per ml of priming</td>
		</tr>
		<tr>
			<td>NaHCO3 8,4% Solution</td>
			<td>B. Braun Melsungen AG</td>
			<td>PZN: 1579775</td>
			<td>3% in priming solution</td>
		</tr>
		<tr>
			<td>Carprofen</td>
			<td>Zoetis Inc., USA</td>
			<td>PZN:00289615</td>
			<td>5mg/kg/BW</td>
		</tr>
		<tr>
			<td>1 Fr PU Catheter</td>
			<td>Instechlabs INC., USA</td>
			<td>C10PU-MCA1301</td>
			<td>carotide artery</td>
		</tr>
		<tr>
			<td>2 Fr PU Catheter</td>
			<td>Instechlabs INC., USA</td>
			<td>C20PU-MJV1302</td>
			<td>jugular vein</td>
		</tr>
		<tr>
			<td>8-0 Silk suture braided</td>
			<td>Ashaway Line &#38; Twine Co., USA</td>
			<td>75290</td>
			<td>ligature</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Piramal Critical Care GmbH</td>
			<td>PZN:9714675</td>
			<td>narcosis</td>
		</tr>
		<tr>
			<td>Spring Scissors - 6mm Blades</td>
			<td>Fine Science Tools GmbH</td>
			<td>15020-15</td>
			<td>instruments</td>
		</tr>
		<tr>
			<td>Spring Scissors - 2mm Blades</td>
			<td>Fine Science Tools GmbH</td>
			<td>15000-03</td>
			<td>instruments</td>
		</tr>
		<tr>
			<td>Halsted-Mosquito Hemostat</td>
			<td>Fine Science Tools GmbH</td>
			<td>13009-12</td>
			<td>instruments</td>
		</tr>
		<tr>
			<td>Dumont #55 Forceps</td>
			<td>Fine Science Tools GmbH</td>
			<td>11295-51</td>
			<td>instruments</td>
		</tr>
		<tr>
			<td>Castroviejo Micro Needle Holder - 9cm</td>
			<td>Fine Science Tools GmbH</td>
			<td>12060-02</td>
			<td>instruments</td>
		</tr>
		<tr>
			<td>Micro Serrefines</td>
			<td>Fine Science Tools GmbH</td>
			<td>18555-01</td>
			<td>instruments</td>
		</tr>
		<tr>
			<td>Bulldog Serrefine</td>
			<td>Fine Science Tools GmbH</td>
			<td>18050-28</td>
			<td>instruments</td>
		</tr>
		<tr>
			<td>Isoflurane Vaporizer Drager 19.1</td>
			<td>Dr&#228;gerwerk AG &#38; Co. KGaA</td>
			<td></td>
			<td>anesthesia 1,3 -2,5%</td>
		</tr>
		<tr>
			<td>Multichannel Data Aquisition Device with ISOHEART Software</td>
			<td>Hugo Sachs Elektronik GmbH, Germany</td>
			<td></td>
			<td>invasive pressure, ECG, t &#176;C</td>
		</tr>
		<tr>
			<td>i-STAT portable device</td>
			<td>Abbott Laboratories, Lake Bluff, Illinois, USA</td>
			<td></td>
			<td>blood gas analysis</td>
		</tr>
		<tr>
			<td>i-STAT CG4+ and CG8+ cartridges</td>
			<td>Abbott Laboratories, Lake Bluff, Illinois, USA</td>
			<td></td>
			<td>blood gas analysis</td>
		</tr>
		<tr>
			<td>C57Bl/6 mice, male, 30 g, 14 weeks old</td>
			<td>Charles River Laboratories</td>
			<td></td>
			<td>housed 1 week before</td>
		</tr>
	</tbody>
</table>

veno-venous extracorporeal membrane oxygenation in a mouse

The use of extracorporeal membrane oxygenation (ECMO) has increased substantially in recent years. ECMO has become a reliable and effective therapy for acute as well as end-stage lung diseases. With the increase in clinical demand and prolonged use of ECMO, procedural optimization and prevention of multi-organ damage are of critical importance. The aim of this protocol is to present a detailed technique of veno-venous ECMO in a non-intubated, spontaneously breathing mouse. This protocol demonstrates the technical design of the ECMO and surgical steps. This murine ECMO model will facilitate the study of pathophysiology related to ECMO (e.g., inflammation,bleeding and thromboembolic events). Due to the abundance of genetically modified mice, the molecular mechanisms involved in ECMO-related complications can also be dissected.

This protocol describes the method of veno-venous ECMO in a mouse. This model is reliable and reproducible, and compared to our previously described model of CPB with respiratory and circulatory arrest12,13, it is less technically demanding to establish.
ECMO flow in the venous system was maintained between 1.5 and 5 mL/min. The mean arterial pressure was kept between 70...

Watch this Scientific Journal Video about Veno-Venous Extracorporeal Membrane Oxygenation in a Mouse at JoVE.com

Veno-Venous Extracorporeal Membrane Oxygenation in a Mouse

Here we present a protocol describing the technique of veno-venous extracorporeal membrane oxygenation (ECMO) in a non-intubated, spontaneously breathing mouse. This murine model of ECMO can be effectively implemented in experimental studies of acute and end-stage lung diseases.

The use of extracorporeal membrane oxygenation (ECMO) has increased substantially in recent years. ECMO has become a reliable and effective therapy for ...

This method can help answer key questions in the field of pulmonary research, such as those related to the therapy of acute and chronic end-stage lung disease. The main advantage of this technique is that it facilitates the starting of molecular and pathological mechanisms of multi-organ damage during prolonged extracorporeal membrane oxygenation as a life-saving procedure. Under clean, non-sterile conditions, use a surgical blade and a dissecting microscope to introduce three fenestrations into the distal third of a two French polyurethane catheter under 16x magnification.Next, place the outflow cannula into the priming solution, switch on the peristaltic pump to fill the extracorporeal membrane oxygenation, or ECMO machine, for priming of the circuit at a one millimeter per minute flow rate. After 30 minutes, add 0.5 liters per minute of 100%oxygen to the oxygenator and confirm the lack of response to toe pinch in an anesthetized adult mouse. After applying ointment to the animal's eyes, make a four millimeter lateral skin incision on the left side of the neck to visualize the jugular vein, and use micro-forceps and cotton swabs to further expose the vessel.Use an 8-0 silk suture to ligate the distal end of the exposed vein, and place a slip knot at the proximal end. Incise the anterior wall of the vein with microscissors, and inject 2.5 international units per gram of heparin into the jugular vein via a 26-gauge branula, raising the head end of the surgical pad by 30 degrees to avoid excessive blood loss during the insertion. Carefully insert the fenestrated two French polyurethane cannula into the proximal end of the jugular vein, rotating the cannula slightly, while pushing the cannula to a four centimeter depth to reach the illiac bifurcation of the inferior vena cava.It's important to push the cannula very gently, but continuously without the use of extra force. If resistance is encountered, pull the cannula back and insert it again. Secure the cannula with 8-0 silk knots, and expose the right jugular vein as just demonstrated.Cannulate the right jugular vein with a one French polyurethane cannula, gently moving the cannula five millimeters toward the right atrium, and secure the cannula with 8-0 silk knots. Catheterize the left femoral artery with another one French polyurethane cannula for invasive pressure monitoring and blood gas analysis, and insert electrocardiogram needles connected to a data acquisition device subcutaneously into both forelimbs, and into the left thoracic wall. Then insert a rectal thermometer connected to a data acquisition device.To initiate veno-venous extracorporeal membrane oxygenation, turn on the pump to an initial flow rate of 0.1 milliliter per minute. After two minutes, adjust the flow rate to three to five milliliters per minute. Under stable flow, monitor the vital parameters via the data acquisition device in the real-time mode, continuously checking the back flow from the venous drainage, and monitoring the level of blood in the air trapper reservoir.Use a one milliliter syringe equipped with a 24-gauge branula to collect any blood leakage, and return the blood to the ECMO circuit via the air trapping reservoir. For blood gas analysis, 10 minutes after ECMO initiation, use a blood sampling cartridge to collect approximately 75 microliters of arterial blood from the inferior vena cava before the oxygenator, directly after the oxygenator, and from the femoral artery. 30 and 60 minutes after ECMO initiation, collect blood from the femoral artery only.45 and 90 minutes after initiation, administer 0.1 milliliter of priming solution to compensate for intravasal liquid loss via the air trapper. Two hours after initiation, collect blood from the oxygenator, inferior vena cava, and femoral artery. After the last blood collection, reduce the flow rate on the pump over the course of five minutes, thereby stopping the ECMO, while continuing to record the vital parameters for another 10 minutes.In an typical experiment, the animal's physiological parameters are recorded every 10 minutes. In this representative experiment, the hematological parameters demonstrated a relevant hemodilution during ECMO, although no blood transfusion was necessary to compensate for moderate anemia. The oxygenation parameters displayed a proper oxygenator performance at an oxygen air mixture at a fraction of inspired oxygen of 1.0.Further, the metabolic changes during ECMO included respiratory alkalosis at the start and at the end of the experiment. No extra blood buffering was performed. It's important to use the proper cannulation technique to absorb blood flows through the ECMO circuit, to monitor the oxygenation parameters via blood gas analysis, and to replace any blood loss caused by blood sampling with extra priming solution.This technique paves the way for researchers in the field of lung disease to significantly improve protocols for life-saving treatments through the use of over 80 available knock-in, knock-out mouse models.

veno-venous-extracorporeal-membrane-oxygenation-in-a-mouse

Research

JoVE Journal

Medicine

12.3K Views.  Hannover Medical School. Questo metodo può aiutare a rispondere a domande chiave nel campo della ricerca polmonare, come quelle relative alla terapia della malattia polmonare acuta e cronica allo stadio finale. Il principale vantaggio di questa tecnica è che facilita l'avvio di meccanismi molecolari e patologici di danno multiorgano durante l'ossigenazione prolungata della membrana extracorporea come procedura salvavita. In condizioni pulite e non sterili, utilizzare una lama chirurgica e un microscopio sezionante ...