Name: an isolated working heart system for large animal models
Uploaded: 2014-06-11T14:30:00.000+00:00
Duration: 9 min 45 s
Description: Watch this Scientific Journal Video about An Isolated Working Heart System for Large Animal Models at JoVE.com

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1，构建Langendorff装置上（ 见图1） <ol><li>使用3/8"管，心脏水库连接到储血槽。 <ol><li>确保该管道经过滚压泵。注意:这可能需要使用两个3/8"至1/4"管连接器来建立一块1/4"的管子要经过滚子泵。 </li><li>储血槽连接到加热器/氧合器带有3/8"管。 </li><li>使用3/8"油管加热器/氧合器连接到一个Y型连接器。 </li><li> Y形连接器的一个臂连接到离心泵，然后离心泵连接到第二Y形连接器（全用3/8"管）。 </li><li>附上一张3/8"油管固定止血阀的朝上的手臂，这将作为两个泡沫陷阱和插入压力传感器的手段。 </li><li>附上一张3/8"油管向下手臂。这部分将附加到AOR<html>抽动套管（ 即后负荷线）。 </li><li>连接Y形连接件的另一臂的方法采用3/8"管预装载室的流入。确保该管道穿过第二轮泵。 </li><li>连接多余的3/8"油管这个室的流出。该部分将要连接到左心房（ 即预置线）。 </li></ol></li><li>氧气罐和加热装置连接到加热器/氧合器。 </li><li>夹紧线从Y连接器将要预装载室，因为这条线将不会被使用，直到心脏被置于工作模式。 </li></ol> 2，压力 - 体积导管准备<ol><li>在37℃水浴，温一瓶生理盐水。 </li><li>浸泡光伏电导导管及压力传感器的温生理盐水至少30分钟。 </li><li>打开的数据采集系统，允许两个热身为至少30分钟。 </li></ol>TLE"&gt; 3。准备Langendorff装置上<ol><li>打开氧气罐，加热装置，辊子泵连接的两个容器，以及离心泵。加热装置应设置为动物的体温（〜36℃）。 </li><li>根据制造商的说明冲洗血液。慢冲洗速度被推荐用于从血液中（ 如 ，过剩的电解质，溶解细胞物质）更彻底清除废物。 </li><li>一旦血液清洗，检查血细胞比容水平前，血液稀释。 </li><li>每瓶洗涤红细胞用生理盐水所需的血球浓度（推荐:20％-25％），并添加到Langendorff装置上。 </li><li>调整两个泵的速度通过​​该系统（不包括预压腔）开始血流量。 </li><li>检查血液的混合物的pH和电解质，并调整至生理所使用的物种。注意:为了防止有害的再灌注后的钙通量，在Langendorff装置上的钙离子水平最初应保持在较低水平（0.3-0.5毫摩尔/升）。 <ol><li>如果有一个减少的血细胞比容与钾同时增加，检查乳酸脱氢酶和血浆中游离血红蛋白，以排除溶血。 </li><li>在溶血情况确实发生，确保所有连接牢固，并没有明显的区域的切向的。 </li></ol></li><li>附上米勒导管插入的PowerLab系统的二次压力槽。 </li><li>根据制造商的说明进行校准的压力传感器。 </li></ol> 4，准备为心，以附件的Langendorff装置上注意:正确逮捕心脏应该用于涉及心脏孤立系统中的任何大型动物实验。缺乏心脏停搏的可能损害心脏，这样就不会产生可测量的工作。 Celsior液，或低钾UNIVER威斯康星SITY（UW）溶液被推荐的，因为不仅是这些解决方案类似于临床上所使用的，但该溶液的低钾有助于防止高钾血症，而电路上。的心脏停搏液量将取决于心脏的大小，用1升水足够的猪心。 <ol><li>从储存容器中迅速取出心脏，倒出来的任何存储解决方案在心室，吸干并称重。 </li><li>为了帮助维持心肌冷温度，直到心脏是准备好了的Langendorff，心脏恢复到储存容器和方向，使主动脉朝上。 </li><li>插入一个3/8"的套管进入主动脉，并与一个拉链结固定。 </li></ol> 5，装上心脏的Langendorff离<ol><li>降低离心泵的缓慢滴入。 </li><li>滴入血液进入主动脉，直到它被充满血液并完全去除空气。 </li><li>仔细附上主动脉çannula到上的Langendorff主动脉导管。使附着时注意。 </li><li>将校准的压力传感器通过止血阀[DS1]到本机主动脉。 </li><li>开始压力测量和调节离心泵的速度，直到所需的灌注压的实现。注:压力可能转变为冠脉阻力的变化。因此，监测动脉压密切，特别是在最初的再灌注。 </li><li>提高温度对加热单元心肌内温度的测量是在37°C。注意:有将是加热单元和变化，心肌内的温度进行了调整之间的延迟。因此，温度变化应逐步进行。 </li><li>得到基线（T = 0）的样品从静脉储血槽，以测量pH，电解质，和其它生化测定。 </li><li>将温度探头插入隔和监视心肌温度。减小加热单元的温度如果心肌温度超过39°C。 </li><li>采取血液样本，每15分钟，调整为所需的实验生理学参数。 <ol><li>约1毫摩尔的钙添加到血液溶液，每隔5分钟，以确保离子钙是&gt; 0.8 mmol / L的工作模式开始前的。 </li></ol></li></ol> 6，把心入工作模式<ol><li>插入一个适当大小的套管插入左心房/肺静脉。这可以与任何一个荷包缝合或拉链领带（如适用）来完成。 </li><li>根据需要关闭在左心房的任何漏洞，可能会泄漏，如其他肺静脉起源与缝合或钉书钉。 </li><li>调整预压室的高度，使得所述柱的高度得到所需的预加载压力。注意:假设血液/晶体混合物的密度等于水的密度，1毫米汞柱=1.36厘米从主动脉瓣到顶部的距离的血液水平在预置储存器（ 例如 ，15毫米汞柱20.4厘米）。 </li><li>松开油管将预载室，慢慢地开始预压辊泵，使预紧室和预紧油管用血完全填满。 </li><li>一旦预压管被完全去除空气，慢慢地填补了左心房和套管用血。 </li><li>而不让任何空气进入系统，连接预紧油管左心房插管。 </li></ol> 7，获取心室压力 - 体积（PV）录音<ol><li>按照制造商的压力和Rho比色皿校正的数据采集系统的使用说明。 </li><li>用3-0聚丙烯缝线在左心室（LV）的顶点放置一个荷包缝合。 </li><li>使用16号针头，使荷包内的刺切口。 </li><li>插入光伏电导导管进入心尖切口。注:理想导管放置将视端上具有LV内的所有感测电极和对LV以外两个激励电极。确保一个适当大小的动物和导管已选定（见讨论）。 </li><li>按下右上角开始记录数据，并确定有多少容积段是活跃的"开始"按钮。 <ol><li>如果所有段不活跃，调整导管位置，直到所有段都是活动的。注:在导管的轻微扭曲可能是必要的，以优化循环形态</li><li>如果无法获得信号在各阶层，调整激励电极，并按照制造商的指示感应电极的位置。 </li></ol></li><li>一旦获得所需的配置，请按照制造商的数量和alpha校准说明。 </li><li>使用正确校准导管，获得至少30秒基线压力容积数据。注:这些压力容积环将提供体积依赖新生削弱心脏功能（ 如 ，心输出量，每搏输出量）的测量。 <ol><li>一旦有足够的循环获得，继续到下一个步骤而无需停止数据的记录，以便获得咬合压力 - 容积数据。 </li></ol></li><li>闭塞预紧管慢慢地用管钳。注:压力 - 容积环应该开始变得更小和向下移动，并在左侧。这就是所谓的"走"。 <ol><li>获得10-15秒的走了下来，然后松开管夹，以便预紧重新进入左心房。 注:这些压力容积环将提供心脏功能的音量独立测量（ 例如 ，预装搏出功，收缩末期压力-容积关系）。 </li><li>通过点击"停止"按钮，在屏幕的右上角停止记录数据。 </li><li>至少等待5分钟重复前闭塞。 </li></ol></li><li>重复步骤7.7和7.8，以获得重复测量。 </li></ol>

<ol>
	<li>Skrzypiec-Spring, M., Grotthus, B., Szelag, A., Schulz, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolated+heart+perfusion+according+to+Langendorff---still+viable+in+the+new+millennium.">Isolated heart perfusion according to Langendorff---still viable in the new millennium.</a> Journal of Pharmacological and Toxicological Methods. 55, 113-126 (2007).</li><li>Cheung, P. Y., 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=Matrix+metalloproteinase-2+contributes+to+ischemia-reperfusion+injury+in+the+heart.">Matrix metalloproteinase-2 contributes to ischemia-reperfusion injury in the heart.</a> Circulation. 101, 1833-1839 (2000).</li><li>Ytrehus, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+ischemic+heart--experimental+models.">The ischemic heart--experimental models.</a> Pharmacological Research: the Official Journal of the Italian Pharmacological Society. 42, 193-203 (2000).</li><li>Ferdinandy, P., Schulz, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nitric+oxide,+superoxide,+and+peroxynitrite+in+myocardial+ischaemia-reperfusion+injury+and+preconditioning.">Nitric oxide, superoxide, and peroxynitrite in myocardial ischaemia-reperfusion injury and preconditioning.</a> British Journal of Pharmacology. 138, 532-543 (2003).</li><li>Ohno, 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=Transplantation+of+cryopreserved+muscle+cells+in+dilated+cardiomyopathy:+effects+on+left+ventricular+geometry+and+function.">Transplantation of cryopreserved muscle cells in dilated cardiomyopathy: effects on left ventricular geometry and function.</a> The Journal of Thoracic and Cardiovascular Surgery. 126, 1537-1548 (2003).</li><li>Hamlin, R. 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=Sensitivity+and+specificity+of+isolated+perfused+guinea+pig+heart+to+test+for+drug-induced+lengthening+of+QTc.">Sensitivity and specificity of isolated perfused guinea pig heart to test for drug-induced lengthening of QTc.</a> Journal of Pharmacological and Toxicological Methods. 49, 15-23 (2004).</li><li>Lee, M. S., Lill, M., Makkar, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stem+cell+transplantation+in+myocardial+infarction.">Stem cell transplantation in myocardial infarction.</a> Reviews in Cardiovascular Medicine. 5, 82-98 (2004).</li><li>Ryugo, 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=Myocardial+protective+effect+of+human+recombinant+hepatocyte+growth+factor+for+prolonged+heart+graft+preservation+in+rats.">Myocardial protective effect of human recombinant hepatocyte growth factor for prolonged heart graft preservation in rats.</a> Transplantation. 78, 1153-1158 (2004).</li><li>Valentin, J. P., Hoffmann, P., De Clerck, F., Hammond, T. G., Hondeghem, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Review+of+the+predictive+value+of+the+Langendorff+heart+model+(Screenit+system)+in+assessing+the+proarrhythmic+potential+of+drugs.">Review of the predictive value of the Langendorff heart model (Screenit system) in assessing the proarrhythmic potential of drugs.</a> Journal of Pharmacological and Toxicological Methods. 49, 171-181 (2004).</li><li>Southworth, R., Blackburn, S. C., Davey, K. A., Sharland, G. K., Garlick, P. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+low+oxygen-carrying+capacity+of+Krebs+buffer+causes+a+doubling+in+ventricular+wall+thickness+in+the+isolated+heart.">The low oxygen-carrying capacity of Krebs buffer causes a doubling in ventricular wall thickness in the isolated heart.</a> Canadian Journal of Physiology and Pharmacology. 83, 174-182 (2005).</li><li>Bell, R. M., Mocanu, M. M., Yellon, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retrograde+heart+perfusion:+the+Langendorff+technique+of+isolated+heart+perfusion.">Retrograde heart perfusion: the Langendorff technique of isolated heart perfusion.</a> Journal of Molecular and Cellular Cardiology. 50, 940-950 (2011).</li><li>Hearse, D. J., Sutherland, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+models+for+the+study+of+cardiovascular+function+and+disease.">Experimental models for the study of cardiovascular function and disease.</a> Pharmacological Research: the Official Journal of the Italian Pharmacological Society. 41, 597-603 (2000).</li><li>Sutherland, F. J., Hearse, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+isolated+blood+and+perfusion+fluid+perfused+heart.">The isolated blood and perfusion fluid perfused heart.</a> Pharmacological Research: the Official Journal of the Italian Pharmacological Society. 41, 613-627 (2000).</li><li>Hill, A. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+studies+of+human+hearts.">In vitro studies of human hearts.</a> Ann Thorac Surg. 79, 168-177 (2005).</li><li>Colah, 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=Ex+vivo+perfusion+of+the+swine+heart+as+a+method+for+pre-transplant+assessment.">Ex vivo perfusion of the swine heart as a method for pre-transplant assessment.</a> Perfusion. 27, 408-413 (2012).</li><li>Ozeki, 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=Heart+preservation+using+continuous+ex+vivo+perfusion+improves+viability+and+functional+recovery.">Heart preservation using continuous ex vivo perfusion improves viability and functional recovery.</a> Circ J. 71, 153-159 (2007).</li><li>Garbade, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional,+metabolic,+and+morphological+aspects+of+continuous,+normothermic+heart+preservation:+effects+of+different+preparation+and+perfusion+techniques.">Functional, metabolic, and morphological aspects of continuous, normothermic heart preservation: effects of different preparation and perfusion techniques.</a> Tissue engineering. Part C, Methods. 15, 275-283 (2009).</li><li>Poston, R. 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=Optimizing+donor+heart+outcome+after+prolonged+storage+with+endothelial+function+analysis+and+continuous+perfusion.">Optimizing donor heart outcome after prolonged storage with endothelial function analysis and continuous perfusion.</a> Ann Thorac Surg. 78, 1362-1370 (2004).</li></ol>

The authors have nothing to disclose.

在Langendorff离体心脏灌流装置和工作心脏模型，导致一些心脏生理学，病理学，药理学和最根本的发现。该模型的多功能性允许其在各种正常和病理条件下1-18具有各种物种的利用。然而，分离的心脏模型不常用于大型哺乳动物，特别是人的心脏，部分由于增加了两个装置的设计和数据收集的复杂性。因此，本文中所呈现的示范协议试图改善这些复杂性，结果在研究分离的猪心脏的相对重现的手段。 我们设置的一个关键组成部分是动脉顺应性/后负荷室更换为离心泵。这种交换允许冠脉灌注压和后负荷中的Langendorff增强控制和心脏的工作模式，respectively，允许这种设置可以很容易地适应不同大小和种类的心。例如，在本设计中，猪心都灌注在40-45毫米汞柱，而人类的心灵都灌注在60-65毫米汞柱。这种变化的压力由调节离心泵的设置简单地实现;该系统的任何组件需要被物理地调整。此外，放置一个压力传感器主动脉根部内监视的根压使期间的Langendorff模式恒定流量和恒定的压力之间的轻松过渡。虽然这种变化消除了经典的柔性小室，离心式泵，通过允许双向流动发生基于该压力梯度，可作为柔性小室。随着收缩和退出每搏输出量，整个泵逆行流的作用是减少后负荷压力，复制主动脉弹性。 此装置的开放式设计也很重要。具有心脏挂在一开一而不是一个半封闭室或漏斗意图，允许对压力 - 容积测量更简单仪器。开放式设计允许使用的心尖切口LV导管放置，避免了跨瓣方法。该跨瓣的方法是技术上更困难的，通常需要透视为妥善安置。此外，这种方法还可以诱发瓣膜关闭不全。通过使用心尖方法，我们轻松，安全地将导管左心室内，同时消除了额外的成本和透视的不便。开放式设计也能提供轻松访问超声心动图和污水的收集，进一步扩大了可以在该系统上进行评估的功能和生化参数。 开放式设计，同时促进数据收集，并做心肌温度调节更加困难。保持生理温度的已知问题一的Langendorff 1或工作心脏系统1,3,11,13。 Langendorff灌流系统通常包含一个热腔，有助于保持适当的温度，但这个房间也使得插入心室压力容积导管更加困难。为了解决这个开放式的设计的下温度调节，氧合器/热交换器放置在水库后。热交换器和主动脉插管之间的最小空间减少热损失，而心肌温度探头确保正常体温。使用夹套管道或外部加热源也可以用来帮助温度控制。 该协议的另一个独特的元素被洗下，研究猪的自体血和生理盐水重构它。虽然，使用增强与晶体缓冲区无论是全血灌流或红细胞的情况并不少见，但它与目前的问题。前者通常需要供体动物，它增加了SUBSTantial成本的实验，而后者可以具有免疫原性的问题，因为它通常是从牛血1,11-13而得。通过洗涤原猪自身的血液，该协议只需要一个单一的动物和免疫原性问题进行消融。此外，在洗涤过程中除去大部分的电解质，这意味着它们可以每实验参数很容易地操纵。最后，通过使用血液保护单元除去大部分蛋白质在血液中，这是该过程的两个优点和缺点。的优点是，任何凝固和免疫/感染性蛋白质除去，减少血块或污染的可能性。的缺点是，这种混合物具有低的渗透压，从而导致心肌水肿和可能损失的心脏功能的一段时间。这个问题可以解决但是，通过添加白蛋白或其它胶体。 确保一个适当大小的进制和导管已被选定作为是使用适当的工作心脏设备一样重要。理想情况下，该导管将被放置的心室空间内所有的感测电极，有两个激励电极（ 即最邻近电极）心室空间之外。如果动物的心室腔太小，或电极之间的间距过大，则所有的段不会在低压空间内完全。同时激励电极的位置可以调节，一个小的LV腔也可导致导管弯曲或曲线，使得数据收集困难。因此，对于大型动物心脏功能分析，建议至少为60千克动物的大小。用这样大小的动物时，为7毫米的电极间距通常允许在导管完全插入。 总之，这份手稿描述了一个孤立的工作心脏系统，简化灌注压调节，数据山坳经文，和整体设计，同时使温度控制只是稍微更加困难。这些修改对离体工作心脏会希望允许其与大型哺乳动物的心脏，包括人类在内的使用量增加，促进我们的心肌病理改变的认识，使更多的临床相关的治疗方案被发现。

我们的许多基本心脏生物学和生理学的认识已经从使用的隔离，逆行灌注豚鼠心脏和离体工作心脏系统实验。这些实验系统仍在广泛应用的今天，以扩大我们的心脑血管的重要议题，包括缺血再灌注损伤知识2，预处理4，基于细胞治疗受损心肌5,7，药物6,9，和心脏移植保护心脏的作用技术8,15-18。 尽管这两个分离的心脏系统可用于任何哺乳动物物种，它们主要用于在小哺乳动物，如豚鼠，大鼠或兔3,12,13。较大的动物模型，如猪和人，提供更多的临床相关数据，但不经常使用，由于成本较高，更大的生物变异，较大的血液灌注液量，并BIGG呃设备1,12-15件。此外，数据收集是比较困难的，特别是对于孤立的工作心中1,3,12-15。由于这些复杂的结果，临床相关的离体心脏模型都很少使用，严重阻碍心血管转化研究进展。 在试图解决这些复杂性，隔离工作心脏制备进行了修改，以创建一个可以很容易地适应不同品种的心灵，包括人类，无论是在恒压或恒流量的Langendorff条件的系统。后负荷遵守腔置换为离心泵简化调节的Langendorff模式和后负荷灌注压在工作模式的过程。而不是封闭的，套水库含有的心脏，这个系统采用开放腔，使数据采集更加容易，通过使利用电导导管经心尖途径。 Moreov呃，这个开放式的设计允许访问的心脏超声心动图评价，进一步拓宽，可以在这些实验中测得的生理参数。这些改进将有希望鼓励其他人使用这个系统对于大型动物转化研究。

<table><tbody><tr><td>PowerLab 16/35 with LabChart Pro</td><td>ADInstruments</td><td>PL3516/P</td><td></td></tr><tr><td>MPVS Ultra Pressure-Volume Unit</td><td>ADInstruments</td><td>880-0168</td><td></td></tr><tr><td>Ventri-Cath Catheter (5F, 12E, 7 mm, DField, Straight, 122 cm)</td><td>Millar</td><td>VENTRI-CATH-507s</td><td></td></tr><tr><td>Pressure Catheter (3.5F, Single, Straight, 100 cm, Ny, Non Repairable)</td><td>Millar</td><td>SPR-524</td><td></td></tr><tr><td>PV Extension Cable (10 ft)</td><td>ADInstruments</td><td>CEC-10PV</td><td></td></tr><tr><td>Catheter Interface Cable (10 ft)</td><td>ADInstruments</td><td>PEC-10D</td><td></td></tr><tr><td>Rho Calibration Cuvette</td><td>ADInstruments</td><td>910-1060</td><td></td></tr><tr><td>MPVS Ultra BNC Cable Pack</td><td>ADInstruments</td><td>880-0172</td><td></td></tr><tr><td>Autotransfusion system</td><td>Sorin</td><td>7320000</td><td></td></tr><tr><td>Bowl Set with Low Volume (135 ml) Centrifuge Bowl</td><td>Sorin</td><td>7135100</td><td></td></tr><tr><td>Oxygenator/Heat Exchanger</td><td>Terumo</td><td>3CXSX18RX</td><td></td></tr><tr><td>Perivascular flow probe</td><td>Transonic Systems</td><td>PAU Series</td><td>Size of flow probe will depend on animal size; for 60 kg pig, recommend 20 or 24 mm probe</td></tr><tr><td>Perivascular flowmeter module</td><td>Transonic Systems</td><td>TS420</td><td></td></tr><tr><td>Myocardial temerpature sensor</td><td>Smiths Medical</td><td>MTS-40015</td><td></td></tr><tr><td>16 G 1&quot; Regular needle</td><td>BD Inc.</td><td>305197</td><td></td></tr><tr><td>4-0 polypropylene suture (double-arm)</td><td>Ethicon</td><td>8526H</td><td>For purse-string stitches</td></tr><tr><td>2-0 polypropylene suture (single-arm)</td><td>Ethicon</td><td>8833H</td><td></td></tr><tr><td>Cable ties</td><td>ULINE</td><td>S-1021</td><td></td></tr><tr><td>Cable tie gun</td><td>ULINE</td><td>H-241</td><td></td></tr><tr><td>Clear, Flexible PVC Tubing</td><td>VWR International</td><td>89068</td><td>Inner diameter depends on cannulas, pumps and other equipment used; most commonly use 1/4&quot;, 3/8&quot; tubing&amp;nbsp;</td></tr><tr><td>Straight Tubing Connectors</td><td>VWR International</td><td>46600</td><td></td></tr><tr><td>Y-Shaped Tubing Connectors</td><td>Thermo Scientific</td><td>6152</td><td></td></tr><tr><td>Jacketed Bubble Trap</td><td>Radnoti</td><td>14040</td><td>For preload chamber</td></tr><tr><td>Centrifugal pump</td><td>Maquet</td><td>70105</td><td>The centrifugal pump and roller pumps were obtained used from perfusion department after clinical use.</td></tr><tr><td>Roller pumps</td><td>Maquet</td><td>HL-20</td><td></td></tr><tr><td>Hemostasis Valve</td><td>Merit Medical</td><td>MAP150</td><td></td></tr><tr><td>Blood gas analyzer</td><td>Instrumentation Laboratory</td><td>570001000</td><td></td></tr></tbody></table>

an isolated working heart system for large animal models

由于其在19 世纪后期推出的的Langendorff离体心脏灌流装置及工作心脏模型的后续发展，已经非常宝贵的工具，用于研究心血管功能和抗病1-15。虽然在豚鼠心脏制剂可以用于任何哺乳动物的心脏，大多数涉及该装置的研究使用小动物模型（ 例如 ，小鼠，大鼠和兔）由于增加的对于较大的哺乳动物1,3,11系统的复杂性。一个主要的困难是，确保在一个范围内的不同心脏大小的恒定冠状动脉灌注压-利用该装置1,11任何实验的一个重要组成部分。通过用离心泵替代经典静压负荷柱，下面描述的工作的Langendorff心脏装置可以很容易地调整和灌注压的严密调节，这意味着相同的设置可以被用于各种硬币s或心脏大小。此外，这种配置也可以无缝地恒定压力或恒定的流量之间的再灌注期间切换，这取决于用户的喜好。此设置的开放性，尽管使温度调节比其他设计更为困难，可以很容易地收集污水和心室压力容积数据。

图1是该电路的原理图，包含所建议的导管放置。该设备的重要组成部分包括以下内容:使用离心泵控制后负荷;压力导管（深蓝色线）在主动脉根部监测灌注压的位置;和压力容积（PV）的导管（淡蓝色线）transapically的放置。虽然在图中的连接似乎是直的连接，"Y"连接器的建议，特别是相对于预压线。 图2示出来自压力传感器灌注的电路，这是一贯之间40-42毫米汞柱，在20分钟的过程中被放置在猪心脏的主动脉根部获得的数据。变化在冠状动脉阻力可以使灌注的压力波动（ 图3）。这些变化可能是次要的和渐进的，纠正他们<html>自我随着时间的推移（ 图3a）。然而，在某些情况下，这些变化可以是突然的，并且需要调整的流量通过离心式泵，以维持所需的灌注压力（ 图3b）。因为变化可能发生，需要监测再灌注期间，主动脉根部的压力。 通过利用经心尖刺切口，压力 - 容积数据可以容易地获得分离的心脏系统上。在该实验中，已被存储在2小时冷（4℃）保存液猪心脏被使用。经初步引进光伏导管，该循环是质量差（ 图4a），与交叉和没有明显的心动周期组件的多个领域。然而，随着左心室内导管的最小操作，环路形态显着提高（ 图4b），从而允许将获得的测量结果。 ve_content"&gt;尽管导管位置的优化，获得的离体电路（ 图5中最上面一行）上的线圈可以具有不同的形态比在体内的循环（ 图5，底行），这些变化，以循环的形态可能是由于对心脏的电路上不同的方向相比，在仰卧的动物，以及缺乏在活的动物中发现的解剖附件（如心包）的。此外，使用起搏导线，以帮助调节心脏速率（推荐的附着位点:室间隔）引入外部电流，导致出现在体外回路的右下部分中的尖峰然而，只要这些循环仍设有心动周期的组件，它们仍能产生可解释的数据。 表1列出了从使用PV导管这些压力-容积环得到的多个功能参数。<html>冷静态存储可能引起心脏，这有助于解释一些相比， 在体内测量的变化，所得到的电路上的值的一些固有的损伤。有些负载因变量内的变化也是由于电路和活的动物之间的预紧力可能不同。 <img alt="图1" fo:content-width="5in" src="/files/ftp_upload/51671/51671fig1highres.jpg" width="500" /> 图的装置1。框图 ​​。 <img alt="图2" fo:content-width="5in" src="/files/ftp_upload/51671/51671fig2highres.jpg" width="500" /> 图再灌注2。代表主动脉根部的压力测量。 <html> g3highres.jpg"宽度="500"/&gt; 图3。改变再灌注期间可能发生的主动脉根部压力的例子 ， 这些变化可能是渐进的，自我修正（A），或突然并要求对离心泵（B）更改设置。 <img alt="图4" fo:content-width="5in" src="/files/ftp_upload/51671/51671fig4highres.jpg" width="500" /> 在导管的初始插入transapically（A）和次要导管操作（B）之后获得图4。压力-容积环。注循环形态，由此循环交叉被消除并在心动周期中的元素的改善是可识别的。在这两组循环的右下部分中的尖峰是由于使用了一个起搏器，它引入了一个非本征电信号。 <img alt="&lt;/ HTML">"图5"FO:内容宽度="5英寸"SRC ="/ files/ftp_upload/51671/51671fig5highres.jpg"宽度="500"/&gt; 图5。采取离体电路（顶行）的代表性的压力-体积的测量，与体内测量（底行）进行比较，同样，起搏器的尖峰可以看出，在这两组体外回路的右下方。 <img alt="表1" fo:content-width="5in" src="/files/ftp_upload/51671/51671table1.jpg" width="500" /> 表1 2小时的冷库（右栏）的CO 后得到的猪心脏的体内 （左列）和对工作心脏设备功能参数:心输出量; E A:动脉弹性; EDP​​VR:舒张末期压力 - 容积关系; EDV:舒张末期容积; ESPVR:收缩末期压力 - 容积关系; PRSW:预载，搏出功;聚乙烯醇:压力 - 容积面积; SV:每搏输出量;南方周末:工作行程。

Watch this Scientific Journal Video about An Isolated Working Heart System for Large Animal Models at JoVE.com

An Isolated Working Heart System for Large Animal Models

Most studies involving the Langendorff apparatus use small animal models due to the increased complexity of systems for larger mammals. We describe a Langendorff system for large animal models that allows for use across a range of species, including humans, and relatively easy data acquisition.

一个孤立的工作心脏系统的大型动物模型

Since its introduction in the late 19th century, the Langendorff isolated heart perfusion apparatus, and the subsequent development of the working heart ...

an-isolated-working-heart-system-for-large-animal-models

Research

JoVE Journal

Medicine

30.6K 次观看.  Duke University Medical Center. Most studies involving the Langendorff apparatus use small animal models due to the increased complexity of systems for larger mammals. We describe a Langendorff system for large animal models that allows for use across a range of species, including humans, and relatively easy data acquisition.

视频: An Isolated Working Heart System for Large Animal Models

NADH Fluorescence Imaging of Isolated Biventricular Working Rabbit Hearts

Since its inception by Langendorff1, the isolated perfused heart remains a prominent tool for studying cardiac physiology2. However, it is not well-suited for studies of cardiac metabolism, which require the heart to perform work within the context of physiologic preload and afterload pressures. Neely introduced modifications to the Langendorff technique to establish appropriate left ventricular (LV) preload and afterload pressures3. The model is known as the isolated LV working heart model and has been used extensively to study LV performance and metabolism4-6. This model, however, does not provide a properly loaded right ventricle (RV). Demmy et al. first reported a biventricular model as a modification of the LV working heart model7, 8. They found that stroke volume, cardiac output, and pressure development improved in hearts converted from working LV mode to biventricular working mode8. A properly loaded RV also diminishes abnormal pressure gradients across the septum to improve septal function. Biventricular working hearts have been shown to maintain aortic output, pulmonary flow, mean aortic pressure, heart rate, and myocardial ATP levels for up to 3 hours8.
When studying the metabolic effects of myocardial injury, such as ischemia, it is often necessary to identify the location of the affected tissue. This can be done by imaging the fluorescence of NADH (the reduced form of nicotinamide adenine dinucleotide)9-11, a coenzyme found in large quantities in the mitochondria. NADH fluorescence (fNADH) displays a near linearly inverse relationship with local oxygen concentration12 and provides a measure of mitochondrial redox state13. fNADH imaging during hypoxic and ischemic conditions has been used as a dye-free method to identify hypoxic regions14, 15 and to monitor the progression of hypoxic conditions over time10.
The objective of the method is to monitor the mitochondrial redox state of biventricular working hearts during protocols that alter the rate of myocyte metabolism or induce hypoxia or create a combination of the two. Hearts from New Zealand white rabbits were connected to a biventricular working heart system (Hugo Sachs Elektronik) and perfused with modified Krebs-Henseleit solution16 at 37 &deg;C. Aortic, LV, pulmonary artery, and left &amp; right atrial pressures were recorded. Electrical activity was measured using a monophasic action potential electrode. To image fNADH, light from a mercury lamp was filtered (350&plusmn;25 nm) and used to illuminate the epicardium. Emitted light was filtered (460&plusmn;20 nm) and imaged using a CCD camera. Changes in the epicardial fNADH of biventricular working hearts during different pacing rates are presented. The combination of the heart model and fNADH imaging provides a new and valuable experimental tool for studying acute cardiac pathologies within the context of realistic physiological conditions.

The objective is to monitor the mitochondrial redox state of isolated hearts within the context of physiologic preload and afterload pressures. A biventricular working rabbit heart model is presented. High spatiotemporal resolution fluorescence imaging of NADH is used to monitor the mitochondrial redox state of epicardial tissue.

NADH的荧光成像隔离双心室工作离体兔心

Since its inception by Langendorff1, the isolated perfused heart remains a prominent tool for studying cardiac physiology2. However, it is not well-suited ...

科研

医学

The Inverted Heart Model for Interstitial Transudate Collection from the Isolated Rat Heart

The present protocol describes a unique approach that enables the collection of cardiac transudate (CT) from the isolated, saline-perfused rat heart. After isolation and retrograde perfusion of the heart according to the Langendorff technique, the heart is inverted into an upside-down position and is mechanically stabilized by a balloon catheter inserted into the left ventricle. Then, a thin latex cap &#8211; previously cast to match the average size of the rat heart &#8211; is placed over the epicardial surface. The outlet of the latex cap is connected to silicon tubing, with the distal opening 10 cm below the base level of the heart, creating slight suction. CT continuously produced on the epicardial surface is collected in ice-cooled vials for further analysis. The rate of CT formation ranged from 17 to 147 &#181;L/min (n = 14) in control and infarcted hearts, which represents 0.1-1% of the coronary venous effluent perfusate. Proteomic analysis and high performance liquid chromatography (HPLC) revealed that the collected CT contains a wide spectrum of proteins and purinergic metabolites.

This protocol describes a method to collect cardiac interstitial fluid from the isolated, perfused rat heart. To physically separate interstitial transudate from coronary venous effluent perfusate, the Langendorff perfused heart is inverted, and the transudate (interstitial fluid) formed on the cardiac surface is collected using a soft latex cap.

从孤立的大鼠心脏的间质渗出物收集的倒置心脏模型

The present protocol describes a unique approach that enables the collection of cardiac transudate (CT) from the isolated, saline-perfused rat heart. ...

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.

正交心脏移植的临床前猪模型

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

Pre-clinical Model of Cardiac Donation after Circulatory Death

Cardiac transplantation demand is on the rise; nevertheless, organ availability is limited due to a paucity of suitable donors. Organ donation after circulatory death (DCD) is a solution to address this limited availability, but due to a period of prolonged warm ischemia and the risk of tissue injury, its routine use in cardiac transplantation is seldom seen. In this manuscript we provide a detailed protocol closely mimicking current clinical practices in the context of DCD with continuous monitoring of heart function, allowing for the evaluation of novel cardioprotective strategies and interventions to decrease ischemia-reperfusion injury.
In this model, the DCD protocol is initiated in anesthetized Lewis rats by stopping ventilation to induce circulatory death. When systolic blood pressure drops below 30 mmHg, the warm ischemic time is initiated. After a pre-set warm ischemic period, hearts are flushed with a normothermic cardioplegic solution, procured, and mounted onto a Langendorff ex vivo heart perfusion system. Following 10 min of initial reperfusion and stabilization, cardiac reconditioning is continuously evaluated for 60 min using intraventricular pressure monitoring. A heart injury is assessed by measuring cardiac troponin T and the infarct size is quantified by histological staining. The warm ischemic time can be modulated and tailored to develop the desired amount of structural and functional damage. This simple protocol allows for the evaluation of different cardioprotective conditioning strategies introduced at the moment of cardioplegia, initial reperfusion and/or during ex vivo perfusion. Findings obtained from this protocol can be reproduced in large models, facilitating clinical translation.

This protocol shows a simple and flexible approach for the evaluation of new conditioning agents or strategies to increase the feasibility of cardiac donation after circulatory death.

循环死亡后心脏捐献的临床前模型

Cardiac transplantation demand is on the rise; nevertheless, organ availability is limited due to a paucity of suitable donors. Organ donation after ...

Optocardiography and Electrophysiology Studies of Ex Vivo Langendorff-perfused Hearts

Small animal models are most commonly used in cardiovascular research due to the availability of genetically modified species and lower cost compared to larger animals. Yet, larger mammals are better suited for translational research questions related to normal cardiac physiology, pathophysiology, and preclinical testing of therapeutic agents. To overcome the technical barriers associated with employing a larger animal model in cardiac research, we describe an approach to measure physiological parameters in an isolated, Langendorff-perfused piglet heart. This approach combines two powerful experimental tools to evaluate the state of the heart: electrophysiology (EP) study and simultaneous optical mapping of transmembrane voltage and intracellular calcium using parameter sensitive dyes (RH237, Rhod2-AM). The described methodologies are well suited for translational studies investigating the cardiac conduction system, alterations in action potential morphology, calcium handling, excitation-contraction coupling and the incidence of cardiac alternans or arrhythmias.

The objective of this study was to establish a method for investigating cardiac dynamics using a translational animal model. The described experimental approach incorporates dual-emission optocardiography in conjunction with an electrophysiological study to assess electrical activity in an isolated, intact porcine heart model.

前维沃·兰根多夫注入心脏的心电生理学研究

Small animal models are most commonly used in cardiovascular research due to the availability of genetically modified species and lower cost compared to ...

Semi-Minimal Invasive Method to Induce Myocardial Infarction in Rats and the Assessment of Cardiac Function by an Isolated Working Heart System

Myocardial infarction (MI) remains the main contributor to morbidity and mortality worldwide. Therefore, research on this topic is mandatory. An easily and highly reproducible MI induction procedure is required to obtain further insight and better understanding of the underlying pathological changes. This procedure can also be used to evaluate the effects or potency of new and promising treatments (as drugs or interventions) in acute MI, subsequent remodeling and heart failure (HF). After intubation and pre-operative preparation of the animal, an anesthetic protocol with isoflurane was performed, and the surgical procedure was conducted&#160;quickly. Using a minimally invasive approach, the left anterior descending artery (LAD) was located and occluded by a ligature. The occlusion can be performed acutely for subsequent reperfusion (ischemia/reperfusion injury). Alternatively, the vessel can be ligated permanently to investigate the development of chronic MI, remodeling or HF. Despite common pitfalls, the drop-out rates are minimal. Various treatments such as remote ischemic conditioning can be examined for their cardioprotective potential pre-, peri- and post-operatively. The post-operative recovery was quick as the anesthesia was precisely controlled and the duration of the operation was short. Post-operative analgesia was administered for three days. The minimally invasive procedure reduces the risk of infection and inflammation. Furthermore, it facilitates rapid recovery. The &#8220;working heart&#8221; measurements were performed ex vivo and enabled precise control of preload, afterload and flow. This procedure requires specific equipment and training for adequate performance. This manuscript provides a detailed step-by-step introduction for conducting these measurements.

This article presents an efficient method to perform myocardial ischemia and subsequent chronic reperfusion in rats using a minimally invasive approach. In addition, left ventricular hemodynamic function of rats is assessed by echocardiography and isolated working heart methods.&#160;

诱导大鼠心肌梗死的半微创方法及独立工作心脏系统对心脏功能的评估

Myocardial infarction (MI) remains the main contributor to morbidity and mortality worldwide. Therefore, research on this topic is mandatory. An easily ...

Large Animal Model for Evaluating the Efficacy of the Gene Therapy in Ischemic Heart

Coronary artery disease is one of the significant causes of mortality and morbidity worldwide. Despite the progression of current therapeutics, a considerable proportion of coronary artery disease patients remain symptomatic. Gene therapy-mediated therapeutic angiogenesis offers a novel therapeutic method for improving myocardial perfusion and relieving symptoms. Gene therapy with different angiogenic factors has been studied in few clinical trials. Due to the novelty of the method, the progress of myocardial gene therapy is a continuous path from bench to bedside. Therefore, large animal models are needed for evaluating the safety and efficacy. The more the large animal model identifies the original disease and the endpoints used in clinics, the more predictable outcomes are from clinical trials. Here, we introduce a large animal model for evaluating the efficacy of the gene therapy in the ischemic porcine heart. We use clinically relevant imaging methods such as ultrasound imaging and 15H2O-PET. For targeting the gene transfers into the desired area, electroanatomical mapping is used. The aim of this method is: (1) to mimic chronic coronary artery disease, (2) to induce therapeutic angiogenesis at hypoxic areas of the heart, and (3) to evaluate the safety and efficacy of the gene therapy by using relevant endpoints.

Myocardial gene therapy for ischemic heart disease holds great promise for future therapeutics. Here, we introduce a large animal model for evaluating the efficacy of gene therapy in the ischemic heart.

用于评估基因治疗缺血性心脏疗效的大型动物模型

Coronary artery disease is one of the significant causes of mortality and morbidity worldwide. Despite the progression of current therapeutics, a ...

Rodent Working Heart Model for the Study of Myocardial Performance and Oxygen Consumption

Isolated working heart models have been used to understand the effects of loading conditions, heart rate and medications on myocardial performance in ways that cannot be accomplished in vivo. For example, inotropic medications commonly also affect preload and afterload, precluding load-independent assessments of their myocardial effects in vivo. Additionally, this model allows for sampling of coronary sinus effluent without contamination from systemic venous return, permitting assessment of myocardial oxygen consumption. Further, the advent of miniaturized pressure-volume catheters has allowed for the precise quantification of markers of both systolic and diastolic performance. We describe a model in which the left ventricle can be studied while performing both volume and pressure work under controlled conditions. 
In this technique, the heart and lungs of a Sprague-Dawley rat (weight 300-500 g) are removed en bloc under general anesthesia. The aorta is dissected free and cannulated for retrograde perfusion with oxygenated Krebs buffer. The pulmonary arteries and veins are ligated and the lungs removed from the preparation. The left atrium is then incised and cannulated using a separate venous cannula, attached to a preload block. Once this is determined to be leak-free, the left heart is loaded and retrograde perfusion stopped, creating the working heart model. The pulmonary artery is incised and cannulated for collection of coronary effluent and determination of myocardial oxygen consumption. A pressure-volume catheter is placed into the left ventricle either retrograde or through apical puncture. If desired, atrial pacing wires can be placed for more precise control of heart rate. This model allows for precise control of preload (using a left atrial pressure block), afterload (using an afterload block), heart rate (using pacing wires) and oxygen tension (using oxygen mixtures within the perfusate).

Isolated working heart models can be used to measure the effect of loading conditions, heart rate, and medications on myocardial performance and oxygen consumption. We describe methods for preparation of a rodent left heart working model that permits study of systolic and diastolic performance and oxygen consumption under various conditions.

灭鼠工作心脏模型心肌的性能和氧耗的研究

Isolated working heart models have been used to understand the effects of loading conditions, heart rate and medications on myocardial performance in ways ...

生物学

Dissection Techniques and Histological Sampling of the Heart in Large Animal Models for Cardiovascular Diseases

The standard gross examination and sampling are key elements in the reproducibility and success of experimental studies of cardiovascular diseases carried out in large animals. Considering the complex anatomy of the heart, interspecies differences, and the types of compensatory and pathological reactions, consistent protocols are challenging to implement. The utilization of multiple dissection protocols is usually adapted to suit the prosector's experience, and personal preference continues to be a source of experimental and interobserver variability. Here, the aim is to present the main anatomical features and landmarks, dissection protocols, and histological sampling standards of the heart in some commonly used species (including dogs, pigs, ruminants, and cats) as models of cardiovascular diseases.
Two standard gross examination protocols are presented here. First, the inflow-outflow method, which follows the physiological blood flow direction through the heart and large vessels (frequently used in dogs, ruminants, and pigs), and second, the four-chamber dissection technique (exemplified in cats). Both techniques can be adapted to any species in certain experimental circumstances. The sampling protocols include all the areas of interest (sinoatrial node, ventricles, interventricular septum, atria, valves, and aorta), and if properly carried out, improve both the reproducibility and reliability of experimental studies.

Due to the complex anatomy, a consistently reproducible dissection and harvesting protocol for cardiac samples can be challenging to implement. This manuscript presents the key elements of some standard cardiac dissection protocols, highlighting both the gross examination approaches and the sampling sites commonly used for histopathologic examination.

心血管疾病大型动物模型中心脏的解剖技术和组织学取样

The standard gross examination and sampling are key elements in the reproducibility and success of experimental studies of cardiovascular diseases carried ...

Large-Animal Model of Donation after Circulatory Death and Normothermic Regional Perfusion for Cardiac Assessment

The increase in demand for cardiac transplantation throughout the years has fueled interest in donation after circulatory death (DCD) to expand the organ donor pool. However, the DCD process is associated with the risk of cardiac tissue injury due to the inevitable period of warm ischemia. Normothermic regional perfusion (NRP) allows for an in situ organ assessment, allowing the procurement of hearts determined to be viable. Here, we describe a clinically relevant large-animal model of DCD followed by NRP. Circulatory death is established in anesthetized pigs by stopping mechanical ventilation. After a preset warm ischemia period, an extracorporeal membrane oxygenator (ECMO) is used for a NRP period lasting at least 30 min. During this reperfusion period, the model allows the collection of various myocardial biopsies and blood samples for initial cardiac evaluation. Once NRP is weaned, biochemical, hemodynamic, and echocardiographic assessments of cardiac function and metabolism can be performed before organ procurement. This protocol closely simulates the clinical scenario previously described for DCD and NRP in heart transplantation and has the potential to facilitate studies aimed at decreasing ischemia-reperfusion injury and enhance cardiac functional preservation and recovery.

The protocol describes a large-animal (porcine) model of donation after circulatory death, followed by thoracoabdominal normothermic regional perfusion that closely simulates the clinical scenario in heart transplantation, and has the potential to facilitate therapeutic studies and strategies.

用于心脏评估的循环死亡后捐献和正常区域灌注的大型动物模型

The increase in demand for cardiac transplantation throughout the years has fueled interest in donation after circulatory death (DCD) to expand the organ ...