Name: implantation of total artificial heart in congenital heart disease
Uploaded: 2014-07-18T06:00:00
Duration: 7 min 27 s
Description: Watch this Scientific Journal Video about Implantation of Total Artificial Heart in Congenital Heart Disease at JoVE.com

1. Pre-operative Patient Preparation
<ol>
	<li>The patient was given general anesthesia according to standard procedures.</li>
	<li>He was placed on the operating table in supine position.</li>
	<li>The right neck line and a right atrial PICC line were removed.</li>
	<li>He received central access in the left femoral vein and remained with his arterial line.</li>
	<li>A TEE probe was placed and demonstrated severely depressed biventricular function and significant aortic insufficiency.</li>
</ol>
2. Cardiectomy
<ol>
	<li>The patient was positioned, prepped and draped in the normal sterile fashion for the repeat sternotomy.</li>
	<li>The repeat sternotomy was completed (Figure 4). Immediately noticeable was the extremely enlarged heart and severe adhesions.</li>
	<li>The diaphragmatic surface was dissected out. It was severely adhered secondary to epicardial wires. The patient would not tolerate significant movement of the heart in trying to reach the inferior vena cava (IVC).</li>
	<li>The aorta was dissected.</li>
	<li>The right femoral vein was dissected.</li>
	<li>Pursestrings were placed in the aorta and femoral vein, heparin was administered, and the aorta and right femoral vein were cannulated. The tip of the venous cannula was advanced to the IVC.</li>
	<li>After reaching appropriate activated clotting time (ACT), the patient went onto cardiopulmonary bypass. Since his systemic vascular resistance was markedly elevated due to severe heart failure, aggressive afterload reduction was required to achieve adequate perfusion pressure.</li>
	<li>The patient was placed with an MPA vent to achieve better decompression of the left heart. However, it became obvious with full flow that this would be a difficult hemodynamic circuit to keep stable primarily due to significant aortic insufficiency.</li>
	<li>The superior vena cava (SVC) was dissected and cannulated, and the patient was placed on bicaval cardiopulmonary bypass&#160;(Figure 5).</li>
	<li>The IVC was dissected and the aorta was cross-clamped. This allowed complete decompression of the heart.</li>
	<li>The aorta and the main PA were divided (Figure 6).</li>
	<li>The rest of the ventricular surface including the diaphragmatic surface, left atrial gutter, and right atrial gutter was dissected out. The MPA, the PA branch and the proximal PA branches were also dissected.</li>
	<li>The right ventricle was dissected out, leaving approximately 3-4 mm of muscle below the right AV valve&#160;(Figure 7A).</li>
	<li>The left ventricle was dissected out leaving a 3-5 mm cuff of ventricular muscle below the left AV valve (Figure 7B).</li>
</ol>
3. TAH Implantation
<ol>
	<li>Using a large Prolene on an MH needle, the previously prepared felt strip with Gore-Tex was whip-stitched to fortify the muscular rim of the ventricular muscle cuffs.</li>
	<li>The atrial quick-connect was trimmed to a 3-4 mm rim. It was inverted and sewn to the muscular cuff both on the left and right sides, to prevent scalloping (Figure 8).</li>
	<li>The ventricles were tunneled out just left of the midline and outflow grafts were cut to the appropriate size.</li>
	<li>The Ao and PA cuffs were sewn using running sutures (Figure 9).</li>
	<li>The RV to PA conduit and calcified areas were excised.</li>
	<li>The atrial cuffs were tested for leaks, and then the Ao and PA anastomoses were tested</li>
	<li>A driveline tunnel was created (Figure 10).</li>
	<li>The left TAH ventricle was connected to the left atrial cuff and then to the aorta (Figure 11).</li>
	<li>Then the outflow graft of the Ao was connected to the system and the cross clamp was released slowly (Figure 12a).</li>
	<li>After this, the TAH right ventricle was connected to the atrial cuff of the RA and then to the PA (Figure 12b).</li>
	<li>In the final position, the TAH ventricles were aligned in a parallel fashion because the PA graft did not cross over top of the aortic graft due to the TGA anatomy (Figure 13).</li>
	<li>The right ventricle was de-aired by removing the IVC snare, an active root vent was placed in the ascending Ao and rewarming was completed.</li>
	<li>The lungs were suctioned and ventilated and the TAH was turned on to de-air the active root vent in the ascending Ao.</li>
	<li>The patient was taken off cardiopulmonary bypass, and the rate of the TAH was increased.</li>
	<li>After achieving good hemodynamics and giving protamine, the heart was decannulated.</li>
	<li>Once hemostasis was achieved, four chest tubes were placed: two Blakes in the mediastinum and posterior mediastinum, one large 40 chest tube in the anterior mediastinum, and a right-angle chest tube in the left chest.</li>
	<li>A neopericardium made of thin Gore-Tex was created and placed around the device. Once completed, the entire mediastinum was irrigated with copious amounts of warm antibiotic saline solution.</li>
	<li>The sternum was closed with surgical steel wires, while making sure sternal closure did not cause any compression to the TAH. The skin and underlying tissues were closed in layers.</li>
	<li>After gaining hemostasis in the groin, this area was closed.</li>
	<li>The AICD pocket was cultured, the AICD removed, and a small drain was placed in the pocket.</li>
	<li>The patient tolerated this very complex procedure well and was transferred to the CVICU in a stable hemodynamic and respiratory state. The patient was extubated on postoperative day 2. Unlike management for ventricular assist device, postoperative care TAH does not require inotropes. Fluid control and afterload reduction are the main parts of postoperative care. Anticoagulation was commenced at day 2 per the manufacture&#39;s protocol.</li>
</ol>

<ol>
	<li>Kirsch, 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=SynCardia+temporary+total+artificial+heart+as+bridge+to+transplantation:+current+results+at+la+piti&#233;+hospital.">SynCardia temporary total artificial heart as bridge to transplantation: current results at la piti&#233; hospital.</a> Ann Thorac Surg. 95 (5), 1640-1646 (2013).</li><li>Copeland, 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=Total+artificial+hearts:+bridge+to+transplantation.">Total artificial hearts: bridge to transplantation.</a> Cardiol Clin. 21 (1), 101-113 (2003).</li><li>Roussel, 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=CardioWest+(Jarvik)+total+artificial+heart:+a+single-center+experience+with+42+patients.">CardioWest (Jarvik) total artificial heart: a single-center experience with 42 patients.</a> Ann Thorac Surg. 87 (1), 124-129 (2009).</li><li>Slepian, M., Alemu, Y., Soares, J., Smith, R., Einav, S., Bluestein, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Syncardia+total+artificial+heart:+in+vivo,+in+vitro,+and+computational+modeling+studies.">The Syncardia total artificial heart: in vivo, in vitro, and computational modeling studies.</a> J Biomech. 46 (2), 266-275 (1016).</li><li>Koyak, Z., 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=Sudden+cardiac+death+in+adult+congenital+heart+disease.">Sudden cardiac death in adult congenital heart disease.</a> Circulation. 126 (16), 1944-1954 (2012).</li><li>Shaddy, 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=Applying+heart+failure+guidelines+to+adult+congenital+heart+disease+patients.">Applying heart failure guidelines to adult congenital heart disease patients.</a> Expert Rev Cardiovasc Ther. 6 (2), 165-174 (2008).</li><li>Warnes, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transposition+of+the+great+arteries.">Transposition of the great arteries.</a> Circulation. 114, 2699-2709 (2006).</li><li>Rutledge, J., Nihill, M., Fraser, C., Smith, O., McMahon, C., Bezold, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Outcome+of+121+patients+with+congenitally+corrected+transposition+of+the+great+arteries.">Outcome of 121 patients with congenitally corrected transposition of the great arteries.</a> Pediatr Cardiol. 23, 137-145 (2002).</li><li>Graham, 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=Long-term+outcome+in+congenitally+corrected+transposition+of+the+great+arteries:+a+multi-institutional+study.">Long-term outcome in congenitally corrected transposition of the great arteries: a multi-institutional study.</a> J Am Coll Cardiol. 36, 255-261 (2000).</li><li>Voskuil, 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=Postsurgical+course+of+patients+with+congenitally+corrected+transposition+of+the+great+arteries.">Postsurgical course of patients with congenitally corrected transposition of the great arteries.</a> Am J Cardiol. 83, 558-562 (1999).</li><li>Hoffman, J., Kaplan, S., Liberthson, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prevalence+of+congenital+heart+disease.">Prevalence of congenital heart disease.</a> Am Heart J. 147 (3), 425-439 (2004).</li><li>Marelli, A., Mackie, A., Ionescu-Ittu, R., Rahme, E., Pilote, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Congenital+Heart+Disease+in+the+General+Population:+Changing+Prevalence+and+Age+Distribution.">Congenital Heart Disease in the General Population: Changing Prevalence and Age Distribution.</a> Circulation. 115, 163-172 (2007).</li><li>DiNardo, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heart+failure+associated+with+adult+congenital+heart+disease.">Heart failure associated with adult congenital heart disease.</a> Semin Cardiothorac Vasc Anesth. 17, 44-54 (2013).</li></ol>

Production of this video-article was sponsored by SynCardia.

The TAH is designed as a bridge to cardiac transplant for patients with normally structured hearts. It enables patients to regain health and stamina as they await a donor heart. Previously, patients with malformed hearts were not considered candidates for receiving a TAH due to the challenges presented by the unusual anatomy. This article highlights that the TAH, with modification, is a viable option for patients with CCTGA, a congenital condition which features l-looped ventricles and transposed great arteries in the setting of usual atrial arrangement. Implanting the TAH in a patient with CCTGA requires a technical modification, with the right and left pumps implanted in a parallel orientation instead of the typical crossed arrangement.
The report also demonstrates that the TAH may provide a simpler solution than placement of VADs in critically ill patients with complex cardiac lesions. In this case, the patient had severe AI and obstruction of a conduit between the LV and PA. The TAH was considered a better option than support with a VAD, which would have required multiple concomitant surgical procedures. The patient in this case report was able to return home and regain health and strength prior to being successfully bridged to heart transplantation five months after receiving the TAH.
With advances in medical and surgical treatment, increasing numbers of patients with CHD are surviving to adulthood11,12. The prevalence of adults with severe CHD increased 85% between 1985 and 200012. The population of adults with CHD now outnumbers that of children with CHD, and a significant subset of this adult population has an increased risk of HF13. As demonstrated in this case, the TAH provides an additional option for CHD patients with HF. In the light of the increasing number of adult patients with HF due to congenital heart disease, this case should represent the beginning of the new era of mechanical circulatory support for those with malformed hearts.

The total artificial heart (TAH) was developed as a bridge to cardiac transplant in patients with heart failure (HF)1-4. The device is a mechanical circulatory support system which replaces the ventricles, with the purpose of extending life until a suitable donor heart becomes available. Congenital heart conditions may sometimes lead to HF, with patients requiring circulatory support5,6.&#160;In individuals with CCTGA, the aorta and pulmonary artery (PA) are transposed and the ventricles are inverted7. The condition may eventually cause HF due to an inability of the morphologic right ventricle (RV) to pump against systemic vascular resistance8-10.
In the case presented here, the patient underwent multiple childhood surgeries for his CCTGA, including a Rastelli repair and a subsequent transvenous dual chamber pacing system. As a teenager, he developed symptoms of HF due to dysfunction of the systemic RV. His condition was complicated by the presence of severe aortic insufficiency (AI) and obstruction of the conduit placed between the left ventricle (LV) to PA. After multiple hospitalizations, including placement with an implantable cardioverter defibrillator (ICD), he advanced to end-stage HF and went into renal failure and cardiogenic shock, requiring intubation and circulatory support.
Although the TAH is designed for individuals with normally-structured hearts, the device was considered the patient&#8217;s best option for survival considering the severity of his condition and the presence of complex cardiac lesions. To accommodate his transposed arteries and inverted ventricles, the TAH was modified during implantation, and the surgery was successful. Three months after implantation, he was discharged home. He received a donor heart 5 months after implantation with the TAH.
Case Presentation:
The patient was a 17-year-old Caucasian male with a history of CCTGA, pulmonary atresia, and ventricular septal defect (VSD) (Figures 1A&#160;and 1B). He had an ascending aorta to main pulmonary artery shunt and epicardial pacemaker placed in infancy. At age 4, he underwent classical (Rastelli) repair, consisting of VSD closure and placement of a morphologic LV to PA conduit. A residual VSD was closed with an Amplatzer occluder at age 11. He subsequently received a dual chamber transvenous pacing system. At age 16, he was treated with cardiac resynchronization therapy (CRT).
At age 17, the patient presented to the emergency room (ER) with dyspnea after several days of noncompliance with medication. He reported having a brief episode of chest pain four days prior to the ER visit. The patient was treated with diuretics overnight and was discharged home with medications re-established. Following his hospitalization, cardiac transplantation was discussed in detail with the patient and his family. A complete transplant evaluation was performed and the patient was subsequently listed.
Nine months later, he was admitted to the hospital after an episode of syncope associated with atrial fibrillation. He underwent direct current (DC) cardioversion. Four days after being discharged, he returned to the ER with complaints of chest pain and hemoptysis. He subsequently returned two days later, reporting increased chest pain. Computerized tomography (CT) revealed a pulmonary embolus in a right lower lobe distribution as well as a separate infiltrate. Anticoagulation therapy was initiated. Two weeks later, an implantable cardioverter defibrillator (ICD) was placed following a period of nonsustained ventricular tachycardia.
The patient was discharged nine days after ICD placement but returned four days later complaining of recurrent episodes of dyspnea and palpitations at night when lying down, as well as chronic nausea and decreased appetite. He was re-admitted at this time. His entering medications were digoxin 125 microgram po daily, hydrochlorothiazide 25 mg po daily, warfarin 5.5 mg po daily, enalapril 10 mg po twice daily, furosemide 40 mg po twice daily, and metoprolol 50 mg po twice daily. He was taking Zofran, Colace, Miralax, and Tylenol on an as needed basis. He had no known drug allergies.
Cardiovascular examination was significant for diffuse point of maximal impulse. On auscultation, there was a regular rhythm with a single S1 and fixed, split S2. There was a grade IV/VI, to/fro, systolic/diastolic murmur at the left sternal border. Vitals were heart rate 94, blood pressure 98/54. Lungs were significant for decreased breath sounds at the right base. Chest x-ray revealed severe cardiomegaly with severely congested lung fields. There was a small right pleural effusion<s>.</s> Bloodwork was significant for progressive hyponatremia, an increase in BNP, and a mild increase in his BUN. The patient was noted to have severely depressed biventricular systolic function, and at least moderate conduit obstruction.
The patient&#8217;s HF continued to progress in the following few weeks, with multiple admits to the intensive care unit. After an episode of syncope following arrhythmia, he was admitted and placed on milrinone. He remained milrinone-dependent in the hospital but continued to have progressive HF symptoms. Over a 48&#160;hr period, he went into severe HF with renal failure and required intubation. Within 24 hours of intubation, heart dysfunction progressed, with worsening perfusion. He stopped producing urine, his creatinine began to rise, and he became hypotensive.
Diagnosis, Assessment, and Plan:
The patient was diagnosed with severe HF and cardiogenic shock secondary to CCTGA, status post classic repair. Secondary diagnoses included morphologic LVOT obstruction and VSD. Despite the challenge presented by his congenitally malformed heart, emergent TAH implantation was considered his best chance for survival given his critical condition and complex cardiac adhesions. The alternative solutions of placing extracorporeal membrane oxygenation (ECMO) through the groin or a temporary ventricular assist device (VAD) through the chest or groin were ruled out due to his severe AI and LVOT obstruction. It was felt that stopping the heart and attempting to place a VAD, while also changing the LV to PA conduit and the aortic valve, would not be a viable option and the patient would likely require a biventricular assist device (BiVAD). Dopamine was added to the milrinone to stabilize the patient&#8217;s blood pressure prior to the surgery.
The surgical plan included modification of the TAH, such that the right and left pumps were implanted in a parallel orientation instead of the normal criss-cross arrangement (Figures 2A, 2B,&#160;and 2C). The major determinants of this unusual orientation were l-looped ventricles (a morphologic left ventricle on the right side and vice-versa) and transposed great arteries, with the aorta anterior and leftward to the pulmonary artery (Figures 3A&#160;and&#160;3B).

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implantation of total artificial heart in congenital heart disease

In patients with end-stage heart failure (HF), a total artificial heart (TAH) may be implanted as a bridge to cardiac transplant. However, in congenital heart disease (CHD), the malformed heart presents a challenge to TAH implantation. 
In the case presented here, a 17 year-old patient with congenital transposition of the great arteries (CCTGA) experienced progressively worsening HF due to his congenital condition. He was hospitalized multiple times and received an implantable cardioverter defibrillator (ICD). However, his condition soon deteriorated to end-stage HF with multisystem organ failure. 
Due to the patient's grave clinical condition and the presence of complex cardiac lesions, the decision was made to proceed with a TAH. The abnormal arrangement of the patient's ventricles and great arteries required modifications to the TAH during implantation.
With the TAH in place, the patient was able to return home and regain strength and physical well-being while awaiting a donor heart. He was successfully bridged to heart transplantation 5 months after receiving the device. This report highlights the TAH is feasible even in patients with structurally abnormal hearts, with technical modification.

The patient tolerated the TAH procedure well and three months later he was discharged home with a portable driver. Regular TAH outpatient protocol was followed during this time, including physical and occupational therapy.
Six weeks after discharge, he was admitted after hypertensive crisis caused his driver to function poorly, resulting in reduced cardiac output. He was admitted, emergently intubated and switched over to the Big Blue driver, which re-established good output from the TAH. His condition improved over the course of a few days. He was being re-established on warfarin while awaiting a new portable driver when a suitable donor heart became available and the patient was taken for transplantation. Plasmapheresis (net zero, using 4.2 L of FFP) was performed on the donor heart to clear donor-specific antibodies.
During the surgery, the patient was found to have severe adhesions. The aortic graft was adhered to the posterior sternum and dense adhesions surrounded the TAH. There were no signs of infection. The inferior vena cava (IVC) was very difficult to find because the right ventricle of the TAH was positioned anterior to the IVC. Because of the CCTGA, the PAs were dissected to provide full mobility and the great vessels were then connected in the correct orientation. Due to the abnormal orientation of the heart, especially the left atrium, the lateral side of the IVC was left slightly longer. Surgery was complicated by a significant bleeding from the oropharynx, which necessitated ENT evaluation and packing of the area prior to taking the patient off bypass. A left atrial line was placed through the left atrial anastomosis before coming off cardiopulmonary bypass. Once weaned off bypass, the heart function was quite good. An epicardial echocardiogram demonstrated that all valves were working well, as well as the function of both ventricles. Protamine was given. Meticulous care was taken to achieve hemostasis. The patient tolerated the procedure well and was transferred to the cardiovascular ICU in stable hemodynamic and respiratory state.
<img alt="Figure 1" fo:content-width="5in" src="/files/ftp_upload/51569/51569fig1.jpg" /> 
Figure 1. Congenitally corrected transposition of the great arteries. Patient CT scans, with coronal view (A)&#160;and axial view (B)&#160;showing CCTGA with l-looped ventricles (a morphologic left ventricle on the right side and vice-versa) and transposed great arteries, with the aorta anterior and leftward to the pulmonary artery. A conduit was placed between the morphologic left ventricle and the pulmonary artery.
<img alt="Figure 2" fo:content-width="5in" src="/files/ftp_upload/51569/51569fig2.jpg" /> 
Figure 2. TAH modification. TAH orientation in a normal adult heart, with pumps aligned in a crossed arrangement (A), and modified orientation in a heart with CCTGA (B). Due to abnormal orientation of the great vessels, the pumps need to be in parallel orientation, as seen in the CT (C).
<img alt="Figure 3" fo:content-width="5in" src="/files/ftp_upload/51569/51569fig3.jpg" /> 
Figure 3. CCTGA Anatomy. Normal arrangement of great vessels and ventricles (A), and the anatomical abnormality in CCTGA (B), with the Ao and PA transposed and the ventricles inverted.
<img alt="Figure 4" fo:content-width="5in" src="/files/ftp_upload/51569/51569fig4.jpg" /> 
Figure 4. Median Sternotomy. TAH implantation procedure began with a 5th repeat median sternotomy.
<img alt="Figure 5" fo:content-width="5in" src="/files/ftp_upload/51569/51569fig5.jpg" /> 
Figure 5. Cannulation. The vessels were cannulated and the patient placed on bicaval cardiopulmonary bypass.
<img alt="Figure 6" fo:content-width="5in" src="/files/ftp_upload/51569/51569fig6.jpg" /> 
Figure 6. Division of the Aorta and the main pulmonary artery. The aorta was clamped to stop the heart, prior to starting cardiectomy. The aorta and the main pulmonary artery were divided after aortic cross-clamping.
<img alt="Figure 7" fo:content-width="5in" src="/files/ftp_upload/51569/51569fig7.jpg" /> 
Figure 7. Excision of the Ventricles. The ventricles were excised (A), leaving a 3-5 mm cuff of ventricular muscle below the left and right AV valves (B).
<img alt="Figure 8" fo:content-width="5in" src="/files/ftp_upload/51569/51569fig8.jpg" /> 
Figure 8. Suturing of Atrial Cuffs. After closing the coronary sinus and left atrial appendage to prevent thrombus formation, the atrial cuffs were trimmed and sutured carefully with running suture.
<img alt="Figure 9" fo:content-width="5in" src="/files/ftp_upload/51569/51569fig9.jpg" /> 
Figure 9. Anastomosis of Outflow Grafts. Running suture was used to anastomose outflow grafts to the Ao and PA.
<img alt="Figure 10" fo:content-width="5in" src="/files/ftp_upload/51569/51569fig10.jpg" /> 
Figure 10. Completed Anastomosed Outflow Grafts. The TAH ventricles were brought into the field. The drivelines were passed through the skin.
<img alt="Figure 11" fo:content-width="5in" src="/files/ftp_upload/51569/51569fig11.jpg" /> 
Figure 11. Attachment of Driveline Tunnels. Starting with the left side, the TAH was connected to the atrial cuff and then to the aorta.
<img alt="Figure 12" fo:content-width="5in" src="/files/ftp_upload/51569/51569fig12.jpg" /> 
Figure 12. Release of Cross Clamp. After the left TAH ventricle was connected to the left atrial cuff and the aorta, the outflow graft was connected to the system and the cross-clamp was released slowly.
<img alt="Figure 13" fo:content-width="5in" src="/files/ftp_upload/51569/51569fig13.jpg" /> 
Figure 13. Final TAH position. The TAH pumps were oriented in a parallel fashion to accommodate the TGA anatomy.

Watch this Scientific Journal Video about Implantation of Total Artificial Heart in Congenital Heart Disease at JoVE.com

Implantation of Total Artificial Heart in Congenital Heart Disease

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.

In patients with end-stage heart failure (HF), a total artificial heart (TAH) may be implanted as a bridge to cardiac transplant. However, in congenital ...

implantation-of-total-artificial-heart-in-congenital-heart-disease

Research

JoVE Journal

Medicine

Implantation of a Carotid Cuff for Triggering Shear-stress Induced Atherosclerosis in Mice

It is widely accepted that alterations in vascular shear stress trigger the expression of inflammatory genes in endothelial cells and thereby induce atherosclerosis (reviewed in 1 and 2). The role of shear stress has been extensively studied in vitro investigating the influence of flow dynamics on cultured endothelial cells 1,3,4 and in vivo in larger animals and humans 1,5,6,7,8. However, highly reproducible small animal models allowing systematic investigation of the influence of shear stress on plaque development are rare. Recently, Nam et al. 9 introduced a mouse model in which the ligation of branches of the carotid artery creates a region of low and oscillatory flow. Although this model causes endothelial dysfunction and rapid formation of atherosclerotic lesions in hyperlipidemic mice, it cannot be excluded that the observed inflammatory response is, at least in part, a consequence of endothelial and/or vessel damage due to ligation.
In order to avoid such limitations, a shear stress modifying cuff has been developed based upon calculated fluid dynamics, whose cone shaped inner lumen was selected to create defined regions of low, high and oscillatory shear stress within the common carotid artery 10. By applying this model in Apolipoprotein E (ApoE) knockout mice fed a high cholesterol western type diet, vascular lesions develop upstream and downstream from the cuff. Their phenotype is correlated with the regional flow dynamics 11 as confirmed by in vivo Magnetic Resonance Imaging (MRI) 12: Low and laminar shear stress upstream of the cuff causes the formation of extensive plaques of a more vulnerable phenotype, whereas oscillatory shear stress downstream of the cuff induces stable atherosclerotic lesions 11. In those regions of high shear stress and high laminar flow within the cuff, typically no atherosclerotic plaques are observed.
 
In conclusion, the shear stress-modifying cuff procedure is a reliable surgical approach to produce phenotypically different atherosclerotic lesions in ApoE-deficient mice.

The constricting cuff presented in this article is designed to induce atherosclerosis in the murine common carotid artery. Due to the conical shape of its inner lumen the implanted cuff generates well-defined regions of low, high and oscillatory shear stress triggering the development of atherosclerotic lesions of different inflammatory phenotypes.

It is widely accepted that alterations in vascular shear stress trigger the expression of inflammatory genes in endothelial cells and thereby induce ...

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

Implantable cardioverter-defibrillators (ICDs) terminate ventricular tachycardia (VT) and ventricular fibrillation (VF) with high efficacy and can protect patients from sudden cardiac death (SCD). However, inappropriate shocks may occur if tachycardias are misdiagnosed. Inappropriate shocks are harmful and impair patient quality of life. The risk of inappropriate therapy increases with lower detection rates programmed in the ICD. Single-chamber detection poses greater risks for misdiagnosis when compared with dual-chamber devices that have the benefit of additional atrial information. However, using a dual-chamber device merely for the sake of detection is generally not accepted, since the risks associated with the second electrode may outweigh the benefits of detection. Therefore, BIOTRONIK developed a ventricular lead called the LinoxSMART S DX, which allows for the detection of atrial signals from two electrodes positioned at the atrial part of the ventricular electrode. This device contains two ring electrodes; one that contacts the atrial wall at the junction of the superior vena cava (SVC) and one positioned at the free floating part of the electrode in the atrium. The excellent signal quality can only be achieved by a special filter setting in the ICD (Lumax 540 and 740 VR-T DX, BIOTRONIK). Here, the ease of implantation of the system will be demonstrated.

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 second electrode.

Implantable cardioverter-defibrillators (ICDs) terminate ventricular tachycardia (VT) and ventricular fibrillation (VF) with high efficacy and can protect ...

Implantation of the Syncardia Total Artificial Heart

With advances in technology, the use of mechanical circulatory support devices for end stage heart failure has rapidly increased. The vast majority of such patients are generally well served by left ventricular assist devices (LVADs). However, a subset of patients with late stage biventricular failure or other significant anatomic lesions are not adequately treated by isolated left ventricular mechanical support. Examples of concomitant cardiac pathology that may be better treated by resection and TAH replacement includes: post infarction ventricular septal defect,&#160;aortic root aneurysm / dissection, cardiac allograft failure, massive ventricular thrombus, refractory malignant arrhythmias (independent of filling pressures), hypertrophic / restrictive cardiomyopathy, and complex congenital heart disease. Patients often present with cardiogenic shock and multi system organ dysfunction. Excision of both ventricles and orthotopic replacement with a total artificial heart (TAH) is an effective, albeit extreme, therapy for rapid restoration of blood flow and resuscitation. Perioperative management is focused on end organ resuscitation and physical rehabilitation. In addition to the usual concerns of infection, bleeding, and thromboembolism common to all mechanically supported patients, TAH patients face unique risks with regard to renal failure and anemia. Supplementation of the abrupt decrease in brain natriuretic peptide following ventriculectomy appears to have protective renal effects. Anemia following TAH implantation can be profound and persistent. Nonetheless, the anemia is generally well tolerated and transfusion are limited to avoid HLA sensitization. Until recently, TAH patients were confined as inpatients tethered to a 500 lb pneumatic console driver. Recent introduction of a backpack sized portable driver (currently under clinical trial) has enabled patients to be discharged home and even return to work. Despite the profound presentation of these sick patients, there is a 79-87% success in bridge to transplantation.

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.

With advances in technology, the use of mechanical circulatory support devices for end stage heart failure has rapidly increased. The vast majority of ...

Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery (SALLI) MRI in Rats

Small animal magnetic resonance imaging is an important tool to study cardiac function and changes in myocardial tissue. The high heart rates of small animals (200 to 600 beats/min) have previously limited the role of CMR imaging. Small animal Look-Locker inversion recovery (SALLI) is a T1 mapping sequence for small animals to overcome this problem 1. T1 maps provide quantitative information about tissue alterations and contrast agent kinetics. It is also possible to detect diffuse myocardial processes such as interstitial fibrosis or edema 1-6. Furthermore, from a single set of image data, it is possible to examine heart function and myocardial scarring by generating cine and inversion recovery-prepared late gadolinium enhancement-type MR images 1.
	The presented video shows step-by-step the procedures to perform small animal CMR imaging. Here it is presented with a healthy Sprague-Dawley rat, however naturally it can be extended to different cardiac small animal models.

Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery SALLI MRI in Rats

Contrast enhanced cardiac magnetic resonance (CMR) imaging allows comprehensive in vivo assessment of the heart in small animal models of cardiovascular disease. Here we detail the procedures to perform CMR imaging, reconstruction and analysis using Small Animal Lock-Locker Inversion Recovery (SALLI) in rats.

Small animal magnetic resonance  imaging is an important tool to study cardiac function and changes in myocardial  tissue. The high heart rates of small ...

Echocardiographic Assessment of the Right Heart in Mice

Transgenic and toxic models of pulmonary arterial hypertension (PAH) are widely used to study the pathophysiology of PAH and to investigate potential therapies. Given the expense and time involved in creating animal models of disease, it is critical that researchers have tools to accurately assess phenotypic expression of disease. Right ventricular dysfunction is the major manifestation of pulmonary hypertension. Echocardiography is the mainstay of the noninvasive assessment of right ventricular function in rodent models and has the advantage of clear translation to humans in whom the same tool is used. Published echocardiography protocols in murine models of PAH are lacking.
In this article, we describe a protocol for assessing RV and pulmonary vascular function in a mouse model of PAH with a dominant negative BMPRII mutation; however, this protocol is applicable to any diseases affecting the pulmonary vasculature or right heart. We provide a detailed description of animal preparation, image acquisition and hemodynamic calculation of stroke volume, cardiac output and an estimate of pulmonary artery pressure.

This article provides a protocol for the echocardiographic assessment of right ventricular size and pulmonary hypertension in mice. Applications include phenotype determination and serial assessment in transgenic and toxin-induced mouse models of cardiomyopathy and pulmonary vascular disease.

Transgenic and toxic models of pulmonary arterial hypertension (PAH) are widely used to study the pathophysiology of PAH and to investigate potential ...

Echocardiographic Approaches and Protocols for Comprehensive Phenotypic Characterization of Valvular Heart Disease in Mice

The aim of this manuscript and accompanying video is to provide an overview of the methods and approaches used for imaging heart valve function in rodents, with detailed descriptions of the appropriate methods for anesthesia, the echocardiographic windows used, the imaging planes and probe orientations for image acquisition, the methods for data analysis, and the limitations of emerging technologies for the evaluation of cardiac and valvular function. Importantly, we also highlight several future areas of research in cardiac and heart valve imaging that may be leveraged to gain insights into the pathogenesis of valve disease in preclinical animal models. We propose that using a systematic approach to evaluating cardiac and heart valve function in mice can result in more robust and reproducible data, as well as facilitate the discovery of previously underappreciated phenotypes in genetically-altered and/or physiologically-stressed mice.

This protocol provides a detailed description of the echocardiographic approach for comprehensive phenotyping of heart and heart valve function in mice.

The aim of this manuscript and accompanying video is to provide an overview of the methods and approaches used for imaging heart valve function in ...

Shunt Surgery, Right Heart Catheterization, and Vascular Morphometry in a Rat Model for Flow-induced Pulmonary Arterial Hypertension

In this protocol, PAH is induced by combining a 60 mg/kg monocrotalin (MCT) injection with increased pulmonary blood flow through an aorto-caval shunt (MCT+Flow). The shunt is created by inserting an 18-G needle from the abdominal aorta into the adjacent caval vein. Increased pulmonary flow has been demonstrated as an essential trigger for a severe form of PAH with distinct phases of disease progression, characterized by early medial hypertrophy followed by neointimal lesions and the progressive occlusion of the small pulmonary vessels. To measure the right heart and pulmonary hemodynamics in this model, right heart catheterization is performed by inserting a rigid cannula containing a flexible ball-tip catheter via the right jugular vein into the right ventricle. The catheter is then advanced into the main and the more distal pulmonary arteries. The histopathology of the pulmonary vasculature is assessed qualitatively, by scoring the pre- and intra-acinar vessels on the degree of muscularization and the presence of a neointima, and quantitatively, by measuring the wall thickness, the wall-lumen ratios, and the occlusion score.

This protocol describes a surgical procedure to create a model for flow-induced pulmonary arterial hypertension (PAH) in rats and the procedures to analyze the principle hemodynamic and histological end-points in this model.

In this protocol, PAH is induced by combining a 60 mg/kg monocrotalin (MCT) injection with increased pulmonary blood flow through an aorto-caval shunt ...

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.

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 ...

Implantation of hiPSC-derived Cardiac-muscle Patches after Myocardial Injury in a Guinea Pig Model

Due to the limited regeneration capacity of the heart in adult mammals, myocardial infarction results in an irreversible loss of cardiomyocytes. This loss of relevant amounts of heart muscle mass can lead to the heart failure. Besides heart transplantation, there is no curative treatment option for the end-stage heart failure. In times of organ donor shortage, organ independent treatment modalities are needed. Left-ventricular assist devices are a promising therapy option, however, especially as destination therapy, limited by its side-effects like stroke, infections and bleedings. In recent years, several cardiac repair strategies including stem cell injection, cardiac progenitors or myocardial tissue engineering have been investigated. Recent improvements in cell biology allow for the differentiation of large amounts of cardiomyocytes derived from human induced pluripotent stem cells (iPSC). One of the cardiac repair strategies currently under evaluation is to transplant artificial heart tissue. Engineered heart tissue (EHT) is a three-dimensional in vitro created cardiomyocyte network, with functional properties of native heart tissue. We have created EHT-patches from hiPSC derived cardiomyocytes. Here we present a protocol for the induction of left ventricular myocardial cryoinjury in a guinea pig, followed by implantation of hiPSC derived EHT on the left ventricular wall.

Here we present a protocol for the induction of left ventricular cryoinjury followed by the implantation of a cardiac muscle patch, derived from human iPS-cell cardiomyocytes in a guinea pig model.

Due to the limited regeneration capacity of the heart in adult mammals, myocardial infarction results in an irreversible loss of cardiomyocytes. This loss ...

Implantation of an Isoproterenol Mini-Pump to Induce Heart Failure in Mice

Isoproterenol (ISO), is a non-selective beta-adrenergic agonist, that is used widely to induce cardiac injury in mice. While the acute model mimics stress-induced cardiomyopathy, the chronic model, administered through an osmotic pump, mimics advanced heart failure in humans. The purpose of the described protocol is to create the chronic ISO-induced heart failure model in mice using an implanted mini-pump. This protocol has been used to induce heart failure in 100+ strains of inbred mice. Techniques on surgical pump implantation are described in detail and may be relevant to anyone interested in creating a heart failure model in mice. In addition, the weekly cardiac remodeling changes based on echocardiographic parameters for each strain and expected time to model development are presented. In summary, the method is simple and reproducible. Continuous ISO administered via the implanted mini-pump over 3 to 4 weeks is sufficient to induce cardiac remodeling. Finally, the success for ISO model creation may be assessed in vivo by serial echocardiography demonstrating hypertrophy, ventricular dilation, and dysfunction.

The chronic administration of isoproterenol via an implanted osmotic pump has been used widely to mimic advanced heart failure in mice. Here, we describe detailed methods in surgical mini-pump implantation for the continuous isoproterenol administration over 3 weeks, as well as, echocardiographic assessment for the successful model creation.

Isoproterenol (ISO), is a non-selective beta-adrenergic agonist, that is used widely to induce cardiac injury in mice. While the acute model mimics ...