Name: Use of Two Intracorporeal Ventricular Assist Devices As a Total Artificial Heart (Video) | JoVE Journal
Uploaded: 2018-05-11T12:30:00.000+00:00
Duration: 8 min 49 s
Description: Learn total heart replacement using two centrifugal pumps in a large animal model for cardiovascular surgery. This method enables real-time pressure assessment and optimal biventricular support settings.

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5 minutes

We would like to thank Laura Janney and Abbot Medical for partial funding. We would also like to thank Duke Perfusion Services and the Large Animal Surgical Core for their assistance during the operations.

Age-matched (for blood donation if needed) calves (weight 80&#8211;90 kg) are cared for in the animal facility. Housing and all treatment procedures are performed in accordance with the guidelines of the Animal Care and Use Committee of Duke University Medical Center.
1. Initiation of Anesthesia
<ol>
	<li>After fasting for 8&#8211;12 h, pre-medicate the calf with Telazol (4.5 mg/kg/intramuscularly) and then administer isoflurane (1&#8211;4%) via a face mask.</li>
	<li>Place the cow in a supine position on a heated table and intubate. Fix the extremities to the table using heavy ties.</li>
	<li>Place an intravenous catheter (14&#8211;20 gauge) in the ear vein.</li>
	<li>Administer diazepam (0.22&#8211;0.44 mg/kg/intravenously) if chewing and swallowing are highly prevalent, or if the animal is biting on the endotracheal tube (ET) tube. Additionally, administer if there is difficulty with intubation to help facilitate airway exposure for intubation.</li>
</ol>
2. Vital Signs and Central Line Settings
<ol>
	<li>Start mechanical ventilation at a tidal volume of 10&#8211;15 mL/kg and a rate of 20&#8211;25 bpm, with isoflurane (0.5&#8211;4%) maintained throughout the procedure.</li>
	<li>Secure the ET tube using ties to ensure no changes in tube position during the operation.</li>
	<li>Continuously monitor the oxygen saturation and heart rates throughout the experiment. Address any difficulties with ventilation or oxygen saturation (SaO2) immediately. These will likely be related to either tube position, or ventilator settings. If it is tube position, adjust the ET tube to achieve adequate tidal volumes.</li>
</ol>
3. Central Vascular Access
<ol>
	<li>Although the following may be done percutaneously using ultrasound guidance, use a cut down approach to better control any local bleeding once the animal is anticoagulated.</li>
	<li>Using the trachea as a landmark, shave the neck fur (with hair clippers), and sterilize the area using betadine. Make a parallel linear incision 1&#8211;2 cm away from the trachea and 20 cm from the manubrium using a no.10 blade scalpel.</li>
	<li>Divide the sternocleidomastoid, and carefully expose the left common carotid artery and internal jugular vein using an electric cautery tool. Use a self-retaining retractor to help with the exposure. Maintain proximal and distal control of both the artery and the vein with large silk sutures (size 0 or 1 silk) or vessel loops.</li>
	<li>Cannulate the left common carotid artery with an 18-gauge catheter for blood pressure monitoring. De-air the line, and if bleeding is encountered, place a 6-0 or 7-0 polypropylene suture in a purse-string fashion around the catheter.
	<ol>
		<li>Attach the pressure transducer to the console and transduce the pressure wave into the software under &#34;systemic pressure&#34;. Read and record the output.</li>
	</ol>
	</li>
	<li>Access the left internal jugular vein for both fluid and drug administration and central venous pressure monitoring. Attach the pressure transducer to the console and transduce the pressure wave into the software under &#34;central venous pressure&#34;. Read and record the output.</li>
	<li>Secure both lines distally to the skin and monitor. Record baseline central venous pressure (CVP) and arterial blood pressure.</li>
</ol>
4. Median Sternotomy and Cardiopulmonary Bypass (CPB)
<ol>
	<li>Palpate the sternum from the manubrium to the xiphoid to choose a spot in the midline and mark using a sterile surgical marker. Shave the fur with a hair clipper, and sterilize the area using betadine. Apply a sterile surgical drape.</li>
	<li>Make an incision using a no.10 blade from the manubrium down to the xiphoid.</li>
	<li>Use an electric cautery tool to divide the pectoralis major down from the sternum, while being perfectly aligned to the midline using manual palpation of the lateral edges of the sternum. Score the midline of the sternum using the electric cautery tool. Begin the sternotomy from the bottom by dividing the xiphoid with heavy scissors.</li>
	<li>Extend the sternotomy cephalad with garden clippers. After each cut, inspect the sternum. Perform digital palpation underneath the sternum, and perform blunt dissection to help the heart and lung fall away from the sternum. Midway through the sternotomy some crossing transversalis muscle may be encountered and these are divided using electric cautery.</li>
	<li>Complete the sternotomy all the way to the manubrium. Take care to stay along the midline as this will be important for healing.</li>
	<li>After the sternotomy is completed, achieve hemostasis by scoring the bleeding muscle edges with the electric cautery tool. Apply bone wax to the marrow of the sternum to help with any residual bleeding.</li>
	<li>Identify the thymus and remove it using the electric cautery tool. Enter the pericardium in a longitudinal fashion, and reflect from the diaphragm up to the aorta.
	<ol>
		<li>Create a pericardial cradle using five 2-0 silk sutures approximating the pericardium to the skin to pull the heart up and support it. Choose all the corners of the opened pericardium and bring them directly anterior to the skin using the silk sutures.</li>
	</ol>
	</li>
	<li>Create a 3-inch-long window between the aorta and pulmonary artery by dissecting the connective tissue to allow for the passing of the aortic cross clamp. Apply a purse-string 4-0 polypropylene suture to the ascending aorta at a location proximal to the bifurcation.</li>
	<li>Circumferentially free the superior vena cava (SVC) using blunt dissection, and apply a second purse string 3-0 polypropylene suture. Establish systemic heparinization using an initial dose of 300 U/kg to achieve an activated clotting time (ACT) greater than 400 s.</li>
	<li>Once the appropriate ACT is achieved, use a no.11 blade to enter the aorta, and insert an 18 Fr arterial cannula. De-air the cannula and attach to the arterial line of CPB. Next, place a 28 Fr SVC cannula in the SVC, and start a CPB.</li>
	<li>While on partial CPB, identify the inferior vena cava (IVC) and cannulate as described for the SVC. Do so while on bypass since it allows for better hemodynamic management given the need to push on the heart for the exposure. 
	NOTE: There may still be a potential for the development of hypotension since CPB is only on as partial support at this point. If hypotension is experienced, this step should be done carefully and broken up to allow the animal&#39;s heart to fill intermittently.</li>
	<li>Once the IVC cannula is securely inserted, splice into the main circuit using a Y connector. Loop both the SVC and IVC with umbilical tape to allow for complete blood isolation from the heart.</li>
</ol>
5. Ventriculectomy
<ol>
	<li>While on full cardiopulmonary support, snare down the SVC and IVC using the previously applied umbilical tape. Apply an aortic cross clamp proximal to the aortic cannulation site. Once the clamp position has been confirmed, start the ventriculectomy.</li>
	<li>Excise the ventricular tissue circumferentially 1-2 cm distal to the right and left atrioventricular groove. Leave the rim of ventricular muscle with the mitral and tricuspid annuli to provide further support for the implantation of the swing rings.</li>
	<li>Transect the sub-valvular apparati for the mitral and tricuspid valves as they are encountered.</li>
	<li>Excise the right ventricle outflow tract muscle with the right ventricular outflow tract (RVOT) including the excision of the pulmonary valve. Also, excise the left ventricular outflow tract (LVOT), but preserve the posterior aspect of the aortic valve as part of the aorto-mitral curtain.</li>
	<li>Divide the interventricular septum last. Identify the orifice of the coronary sinus and ligate with 5-0 polypropylene sutures.</li>
</ol>
6. Implantation of Centrifugal Flow Pumps (CFP)
<ol>
	<li>Use pledgeted, interrupted, 2-0 braided sutures to secure the sewing ring to the ventricular tissue and mitral valve annulus. Exit the sutures on the epicardial surface of the ventricular muscle rim and bring through the sewing ring. This technique avoids &#34;bunching up&#34; of the tissue above the ring which would interfere with the coaptation of the ring with the pump.</li>
	<li>Use a similar approach to attach the sewing ring to the right ventricle muscle rim and tricuspid annulus.</li>
	<li>Attach the CFPs to the sewing rings and secure with the standard locking mechanism. Orient these to allow access to the locking mechanism.</li>
	<li>Adjust the outflow graft length according to the orientation of choice. Once a proper length has been identified, cut the outflow graft. Take care to not make the graft too long as that may cause kinking.</li>
	<li>Use running 4-0 polypropylene sutures to anastomose the outflow grafts to the aorta (for the left heart CFP) and pulmonary artery (for the right heart CFP) in an end to end fashion.</li>
	<li>Prior to completing the anastomoses, release the tape on the SVC and IVC drainage cannulas and allow blood to fill the right and left pump, thus beginning the de-airing process. Place an 18-gauge needle into each of the outflow grafts for further de-airing. Use the ventilator to provide large volume breaths to allow for any air trapped in the pulmonary veins to be returned and de-aired.
	<ol>
		<li>After de-airing is complete, remove the needle, and repair the site using pledgeted 5-0 polypropylene sutures.</li>
	</ol>
	</li>
	<li>Start the pumps at a low rpm speed (3,000 rpm) to allow for forward blood flow, initially with the clamp still in place. Remove the aortic cross clamp and leave some blood volume to enter the pumps.</li>
	<li>Gradually increase the pump speed as the cardiopulmonary support is weaned. Terminate the CPB and support the circulation entirely by the right and left side pumps.</li>
	<li>Determine the final pump speed settings by the venous filling pressures on the right and left side.</li>
	<li>Introduce pressure catheters directly into the pulmonary artery and the pulmonary veins using a purse-string 5-0 polypropylene suture to secure them in place.</li>
	<li>Transduce pressure signals to the software under the labels &#34;pulmonary artery&#34; and &#34;pulmonary vein&#34;. In addition, place ultrasonic flow probes around the ascending aorta and the main pulmonary artery. 
	NOTE: All 4 channels should now be active: 1. &#34;systemic pressure&#34;, 2. &#34;central venous pressure&#34;, 3. &#34;pulmonary artery&#34; and 4. &#34;pulmonary vein&#34;.</li>
</ol>
7. Establishment of Biventricular Assist Device Flow
<ol>
	<li>While gradually decreasing the CPB flow, slowly increase the left CFP and then the right CFP speed while always maintaining a lower right CFP speed than the left CFP.</li>
	<li>Pay careful attention to the hemodynamics, including the systemic blood pressure and CVP. Pulmonary overcirculation is indicated by non-physiological pressures in the pulmonary artery or pulmonary vein.</li>
	<li>Eventually, increase the left CFP and right CFP speeds to achieve a flow of 4 L/min on each device and wean off the CPB. Once hemodynamic stability is achieved, remove the SVC and IVC cannulas and tie down the purse-string sutures.</li>
	<li>Next, remove the aortic cannula and tie down the purse-string suture. Euthanize the animal by slowly turning down, and then stopping both the CFP pumps while the animal is under anesthesia.</li>
</ol>

<ol><li>Mozzafarian, D., et al. American Heart Association Statistics Committee and Stroke Statistics Subcommittee. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Heart+disease+and+stroke+statistics%E2%80%942016+update%3A+a+report+from+the+American+Heart+Association%5BTitle%5D)+AND+%22Circulation%22%5BJournal%5D)">Heart disease and stroke statistics—2016 update: a report from the American Heart Association.</a> Circulation. 133 (4), e38-e360 (2016).</li>
<li>Slaughter, M. S., et al. HeartMate II Investigators. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Advanced+heart+failure+treated+with+continuous-flow+left+ventricular+assist+device%5BTitle%5D)+AND+%22N+Engl+J+Med%22%5BJournal%5D)">Advanced heart failure treated with continuous-flow left ventricular assist device.</a> N Engl J Med. 361 (23), 2241-2251 (2009).</li>
<li>Fang, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Rise+of+the+Machines+%E2%80%94+Left+Ventricular+Assist+Devices+as+Permanent+Therapy+for+Advanced+Heart+Failure%5BTitle%5D)+AND+%22N+Engl+J+Med%22%5BJournal%5D)">Rise of the Machines — Left Ventricular Assist Devices as Permanent Therapy for Advanced Heart Failure.</a> N Engl J Med. 361, 2282-2285 (2009).</li>
<li>Kirklin, J. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Seventh+INTERMACS+annual+report%3A+15%2C000+patients+and+counting%5BTitle%5D)+AND+%22J+Heart+Lung+Transplant%22%5BJournal%5D)">Seventh INTERMACS annual report: 15,000 patients and counting.</a> J Heart Lung Transplant. 34 (12), 1495-1504 (2015).</li>
<li>Leidenfrost, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Right+ventricular+assist+device+with+membrane+oxygenator+support+for+right+ventricular+failure+following+implantable+left+ventricular+assist+device+placement%5BTitle%5D)+AND+%22Eur+J+Cardiothorac+Surg%22%5BJournal%5D)">Right ventricular assist device with membrane oxygenator support for right ventricular failure following implantable left ventricular assist device placement.</a> Eur J Cardiothorac Surg. 49 (1), 73-77 (2016).</li>
<li>Gerosa, G., Gallo, M., Bottio, T., Tarzia, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Successful+heart+transplant+after+1374+days+living+with+a+total+artificial+heart%5BTitle%5D)+AND+%22Eur+J+Cardiothorac+Surg%22%5BJournal%5D)">Successful heart transplant after 1374 days living with a total artificial heart.</a> Eur J Cardiothorac Surg. 49 (4), e88-e89 (2016).</li>
<li>Pelletier, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((System+overview+of+the+fully+implantable+destination+therapy--ReinHeart-total+artificial+heart%5BTitle%5D)+AND+%22Eur+J+Cardiothorac+Surg%22%5BJournal%5D)">System overview of the fully implantable destination therapy--ReinHeart-total artificial heart.</a> Eur J Cardiothorac Surg. 47 (1), 80-86 (2015).</li>
<li>Krabatsch, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Biventricular+circulatory+support+with+two+miniaturized+implantable+assist+devices%5BTitle%5D)+AND+%22Circulation%22%5BJournal%5D)">Biventricular circulatory support with two miniaturized implantable assist devices.</a> Circulation. 124, Suppl 11. S179-S186 (2011).</li>
<li>Milano, C. A., Schroder, J., Daneshmand, M. <a target="_blank" href="http://www.sciencedirect.com/science/article/pii/S1522294216000039">Total Artificial Heart Replacement With 2 Centrifugal Blood Pumps.</a> Oper Tech Thorac Cardiovasc Surg. 20 (3), 306-321 (2016).</li>
<li>Strueber, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Placement+of+2+implantable+centrifugal+pumps+to+serve+as+a+total+artificial+heart+after+cardiectomy%5BTitle%5D)+AND+%22J+Thorac+Cardiovasc+Surg%22%5BJournal%5D)">Placement of 2 implantable centrifugal pumps to serve as a total artificial heart after cardiectomy.</a> J Thorac Cardiovasc Surg. 143 (2), 507-509 (2012).</li>
</ol>

This work was made possible through a research grant from Abbot Medical to Dr. Milano.

In this manuscript, we describe the use of two centrifugal flow VADs as an intracorporeal TAH. This technique maybe very useful to study the effect of artificial circulation on secondary organs such as the lungs and liver. Furthermore, it may be useful for the study of the hemodynamic changes from different pump orientations and flow scenarios. The critical steps within this protocol involve how the sewing rings are attached to the ventricular tissue while also incorporating the valvular annuli for strength. It is crucia...

There has been growth in the number of patients with heart failure, with an estimated 5.7 million adults suffering from this condition in the United States today1. Around 300,000 patients have end stage heart failure with a life expectancy of less than one year. While heart transplantation remains the gold standard therapy for end stage heart failure, it is greatly limited by the number of available donor organs. MCS has been introduced as a viable alternative to heart transplantation especially through the use of VADs2. VADs work by unloading the left ventricle and providing forward flow (supported by a pump) directly into the arterial circulation. VADs may be implanted as a bridge to transplantation as well as a destination therapy for patients that do not qualify for a transplantation3. Since their FDA approval less than a decade ago, the annual number of VADs implanted has surpassed heart transplant numbers, with this number exponentially increasing4. However, in a subset of patients, heart failure is biventricular (i.e. affecting both the left and right ventricle) and simply supporting the left ventricle alone may not provide adequate perfusion. In these situations, the right ventricle requires temporary mechanical support5. This type of &#34;RVAD&#34; requires the use of large cannulas connected to an extracorporeal pump that restricts the patient to the Intensive Care Unit (ICU) while the ventricle recovers. For a limited subset of patients, another option is a TAH6,7. The indications for TAH usage are: a biventricular failure after post infarct, a ventricle septal defect (VSD), a severe restrictive myopathy which precludes ventricular cannulation, and a failed heart transplant requiring chronic support. However, the currently FDA approved TAH device is large and cannot be used in smaller patients. In addition, the pneumatic drivers are sizable and limit the mobility of the patient.
One experimental strategy for some patients is the use of a second VAD to support the right ventricle8,9,10. In this scenario, both ventricles are excised, and two VADs are implanted as a TAH. This has been made possible by the improvements in device design and the shrinking of the device profile. New centrifugal VADs are much smaller, allowing for two VADs to be implanted next to each other to support both the left and right circulation. This approach remains experimental with many important challenges including the device settings to balance the right and left circulation, the orientation of the devices and outflow graft with their influence on hemolysis and other adverse events. The purpose of this protocol is to provide a reproducible approach to TAH replacement with two centrifugal VADs in a cow model.

<table><tbody><tr><td>SPO2&amp;nbsp; and heart rates are to be monitored: Multiparameter</td><td>Meditech Equipment, Co., Ltd.</td><td>MD-908</td><td>hemodynamic monitor intraoperatively</td></tr><tr><td>Viscot Mini XL Surgical Markers</td><td>Amazon</td><td>B007P550WG</td><td>marking sternum before incision</td></tr><tr><td>60W High Power Electric Pet Cat Rabbits Horse Animal Hair Cutting Clipper</td><td>LILY International Business CO., LIMITED&amp;nbsp;</td><td>ZP-293</td><td>Fur shaving</td></tr><tr><td>No. 10 scalpel blade</td><td>Swann-Mortan, England</td><td>301</td><td>Skin incision</td></tr><tr><td>Matzenbaum scissor</td><td>BD-V. Mueller, USA</td><td>CH2006-001</td><td>Vascular exploration</td></tr><tr><td>Scissors</td><td>Felco, USA</td><td>FELCO 200A-50, Felco Professional Bypass Lopper</td><td>For sternotomy</td></tr><tr><td>A self-retractor</td><td>BD-V. Mueller, USA</td><td>AU19270</td><td>SCHUKNECHT Self-Retaining Postauricular Retractor,&amp;nbsp;</td></tr><tr><td>Sternal retractor</td><td>BD-V. Mueller, USA</td><td>CH6950-007</td><td>Cooley sternal retractor</td></tr><tr><td>Pressure transducer (Millar Mikro-Tip, 5Fr)</td><td>Millar, USA</td><td>MillarMikro-Tip, SPR-350S</td><td>Assessment for pulmonary artery or venous pressure</td></tr><tr><td>AD instruments (PowerLab)</td><td>AD instruments, USA</td><td>PowerLab 16/35</td><td>Pressure signal transduction</td></tr><tr><td>Umbilical tapes</td><td>Medline industries Inc., USA</td><td>U11</td><td>For isolation and snaring of superior or inferior vena cava</td></tr><tr><td>Vessel loops</td><td>Aspen Surgical, USA</td><td>3901, 3902 and 3904</td><td>Isolation of vessels</td></tr><tr><td>Silk sutures, 2-0</td><td>Ethicon US, LLC, USA</td><td>SA11G</td><td>For snare of superior or inferior vena cava</td></tr><tr><td>Ticron 2-0</td><td>Covidien, USA</td><td>TicronTM suture</td><td>Vascular suture</td></tr><tr><td>Prolene, 7-0</td><td>Covidien, USA</td><td>Surgipro II</td><td>Vascular suture</td></tr><tr><td>Prolene, 6-0</td><td>Covidien, USA</td><td>Surgipro II</td><td>Vascular suture</td></tr><tr><td>Prolene, 4-0</td><td>Covidien, USA</td><td>Surgipro II</td><td>Vascular suture</td></tr><tr><td>Prolene, 3-0</td><td>Covidien, USA</td><td>Surgipro II</td><td>Vascular suture</td></tr><tr><td>Aortic cannula, 15-18 Fr</td><td>Medtronic, USA</td><td>Elongated-One-Piece-Arterial cannula 3D</td><td>Aortic cannula for setting of cardiopulmonary bypass</td></tr><tr><td>Venous cannula, 28Fr</td><td>Edwards Lifesciences</td><td>single stage</td><td>Venous cannula for setting of cardiopulmonary bypass</td></tr></tbody></table>

use of two intracorporeal ventricular assist devices as a total artificial heart

Use of Two Intracorporeal Ventricular Assist Devices As a Total Artificial Heart

Mechanical circulatory support (MCS) has been introduced as a viable alternative to heart transplantation primarily through the use of intracorporeal ventricular assist devices (VADs) for support of the left ventricle. However, certain clinical scenarios warrant biventricular mechanical support. One strategy for some patients is the excision of both ventricles and the implantation of two VAD pumps as a total artificial heart (TAH). This has recently been made possible by the improvements in device design and the small profile of centrifugal devices. This TAH approach remains experimental with many important challenges such as the device settings to balance the right and left circulation, the orientation of the devices and the outflow graft with their influence on hemolysis and stability, and the outcome of chronic support using such an orientation. This protocol aims to provide a reproducible approach for total artificial heart replacement with two intracorporeal centrifugal VADs in a cow model.

Demonstrated in Figure 1 is the attachment of the sewing rings. Figure 1A shows the "bunching" of the ventricle tissue that may create a problem with pump attachment. Figure 1B represents the correct attachment.
Figure 2 and Figure 3 are two different orientations of the pumps. In ...

Here, we present a protocol using two centrifugal pumps as a total artificial heart replacement.

Mechanical circulatory support (MCS) has been introduced as a viable alternative to heart transplantation primarily through the use of intracorporeal ...

The overall goal of this procedure is to perform a complete heart replacement in a large animal model, using two centrifugal implanted pumps. This method can help answer key questions in the surgical heart failure field, regarding the optimal speed settings for intracorporeal, biventricular support using two centrifugal flow ventricular assist devices. This technique allows for real-time systemic and pulmonary pressure assessments in situations where the total artificial heart is not an option.After performing a sternotomy, score the bleeding muscle edges with an electric cautery tool, and apply bone wax to the sternum to help with any residual bleeding. Use the cautery tool to remove the thymus, and enter the pericardium in a longitudinal fashion, reflecting from the diaphragm to the aorta. Using 520 silk sutures, bring all of the corners of the pericardium directly anterior to the skin, to create a pericardial cradle for supporting the heart.Dissect the connective tissue to create a 3-inch long window between the aorta and the pulmonary artery, then apply a purse string 3-0 polypropylene suture to the ascending aorta, proximal to the bifurcation. Use blunt dissection to circumferentially free the superior vena cava, or SVC, and place a second purse string using a 3-0 polypropylene suture. Administer an initial dose of 300 units of heparin per kilogram, to achieve an activated clotting time greater than 400 seconds, and to establish systemic herparinization.Then use a number 11 blade to incise the aorta, and insert an 18 French arterial cannula. After de-airing the cannula, attach it to the arterial line of the cardio-pulmonary bypass, or CPB. Place a 28 French right-angle cannula in the SVC, and initiate the CPB.Cannulate the inferior vena cava, or IVC, as just demonstrated for the SVC. Then, use a Y-connector to splice together the SVC and IVC drains into one main circuit, and loop both the SVC and IVC with umbilical tape to allow complete blood isolation from the heart. While on full cardio-pulmonary support, use the tape to snare down the SVC and IVC, and apply an aortic cross-clamp proximal to the aortic cannulation site.When the clamp is in place, circumferentially excise the ventricular tissue one to two centimeters distal to the right and left atrial ventricular grooves, leaving the rim of the ventricular muscle with the mitral and tricuspid annuli to provide further support for the implantation of the sewing rings. Transect the sub-valvular apparati for the mitral and tricuspid valves as they are encountered, and excise the right ventricular outflow tract, or RVOT muscle, and the RVOT itself, including the pulmonary valve. Next, open the left ventricular outflow tract, or LVOT, taking care to preserve the posterior aspect of the aortic valve, as part of the aortal mitral curtain.Then, resect the residual intraventricular septum, leaving at least a one centimeter room of muscle at the mitral and tricuspid annuli, and ligate the orifice of the coronary sinus with 5-0 polypropylene sutures. For implantation of the centrifugal flow pumps, or CFP, first use pledgeted interrupted 2-0 braided sutures to secure a sewing ring to the ventricular tissue and mitral valve annulus, exiting the sutures on the epicardial surface of the ventricular muscle rim, and bringing the sutures through the sewing ring. The sutures must be placed in a manner to avoid ventricular tissue bunching when the ring is being tied down.Using a similar approach, attach the sewing ring to the right ventricular muscle rim and tricuspid annulus, and attach the CFPs to the sewing rings using the standard locking mechanism to secure the pumps. Adjust the outflow graft length according to the orientation of choice, and cut the outflow graft to the appropriate length. Bevel the cut of the graft if the diameter is less than that of the aorta or pulmonary artery.Using running 4-0 polypropylene sutures, anastomose the outflow grafts to the aorta for the left CFP, and to the main pulmonary artery for the right CFP, in an end-to-end fashion, releasing the tape on the SVC and IVC drainage cannulas prior to completing the anastomosies, to fill the pumps and grafts. Start the clearing process, allowing blood to fill the right and left pumps, and place an 18-gauge needle into each of the outflow grafts for further de-airing. Use the ventilator to provide large volume breaths to allow any air trapped in the pulmonary veins to be removed.When the de-airing is complete, remove the needle and use pledgeted 5-0 polypropylene sutures to repair the site. Now, start the pumps at 3, 000 RPM, and remove the aortic cross-clamp. Gradually increase the pump speeds while weaning and terminating the CPB, to allow the circulation to be supported entirely by the right and left side pumps.Introduce the pressure catheters directly into the left atrium, and use a purse string 5-0 polypropylene suture to secure the catheters in place. Transduce the pressure signals to the software under the labels pulmonary artery and pulmonary vein. To establish the biventricular assist device flow, slowly increase first the left CFP speed, followed by a slow increase of the right CFP speed, while gradually decreasing the CPB flow.Pay careful attention to the hemodynamics, including the systemic blood pressure and central venous pressure. Increase the left and right CFP speeds as necessary to achieve a flow of approximately four liters per minute on each side, to achieve normal pulmonary artery and vein pressures. Once hemodynamic stability is achieved, remove the SVC and IVC cannulas, and tie down the purse string sutures.In this image, improper ring attachment resulted in bunching of the ventricle tissue, which may create a problem with the pump attachment. Here, the pumps are positioned so that the outflow grafts are short, and exit directly into the connected arteries. In this alternative orientation, the outflow grafts are positioned so that both the right and the left CFPs are able to rotate circumferentially prior to being anastomosed to the pulmonary artery and aorta, respectively.Once mastered, this technique can be performed in about three hours, if done properly.

use-two-intracorporeal-ventricular-assist-devices-as-total-artificial

Research

JoVE Journal

Medicine

The purpose of this manuscript is to briefly review indications, management, and outcomes for the total artificial heart.  Video operative techniques for device implantation are presented.

Implantation of the Syncardia Total Artificial Heart

This is a case report of a patient with congenitally corrected transposition of the great arteries (CCTGA) who received a total artificial heart (TAH) as a bridge to heart transplant. The TAH was successfully implanted with modifications to accommodate the patient's congenitally malformed heart.

Implantation of Total Artificial Heart in Congenital Heart Disease

Percutaneous ventricular assist devices are increasingly being utilized in patients with acute myocardial infarction and cardiogenic shock. Herein, we discuss the mechanism of action and hemodynamic effects of such devices. We also review algorithms and best practices for the implantation, management and weaning of these complex devices.

Utilizing Percutaneous Ventricular Assist Devices in Acute Myocardial Infarction Complicated by Cardiogenic Shock

The following article describes the stepwise procedure for placement of a device (e.g., Tandemheart) in cardiogenic shock (CS) that is a percutaneous left ventricular assist device (pLVAD) and a left atrial to femoral artery bypass (LAFAB) system that bypasses and supports the left ventricle (LV) in CS.

Use of a Percutaneous Ventricular Assist Device/Left Atrium to Femoral Artery Bypass System for Cardiogenic Shock

We present a benchtop protocol to induce thrombosis in ventricular assist devices (VAD) within a recirculating test platform. This method serves to identify thrombogenic hotspots in the blood flow path and can help improve thromboresistance ahead of preclinical testing in animal models.

In Vitro Thrombosis Test for Ventricular Assist Devices

Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices.  Therefore, BIOTRONIK has developed a new electrode called the LinoxSMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the...

A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and  Ease of Implantation

This article describes procedures for implanting a novel hydrogel in failing hearts and quantifying its effect on left ventricular wall stress and function. These procedures have been successfully applied in dogs and humans.

Reduction in Left Ventricular Wall Stress and Improvement in Function in Failing Hearts using Algisyl-LVR

Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the blind.

Development of an Audio-based Virtual Gaming Environment to Assist with Navigation Skills in the Blind

Here, we describe the preparation of viable ventricular slices from adult mice and their use for sharp electrode action potential recordings. These multicellular preparations provide a preserved in vivo like tissue structure, which makes them a valuable model for electrophysiological and pharmacological studies in vitro.

Murine Short Axis Ventricular Heart Slices for Electrophysiological Studies

Here, we present a protocol to produce tachycardia-induced cardiomyopathy in swine. This model represents a potent way to study the hemodynamics of progressive chronic heart failure and the effects of applied treatment.

Tachycardia-Induced Cardiomyopathy As a Chronic Heart Failure Model in Swine

Learn total heart replacement using two centrifugal pumps in a large animal model for cardiovascular surgery. This method enables real-time pressure assessment and optimal biventricular support settings.

Use of Two Intracorporeal Ventricular Assist Devices As a Total Artificial Heart

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