This work was supported by a grant of the Swiss Cardiovascular Foundation to RT.

The protocol follows the institutional guidelines of the human research ethics committee of the University of Zurich.
1. Preparation for Surgery
<ol>
	<li>Clean and prepare the surgical suite in a typical manner. To facilitate communication between the surgeon and the perfusionist, place the heart-lung machine to the left of the patient, opposite to the surgeon.</li>
	<li>Pre-medicate the patient by the oral administration of 5 mg of midazolam, 30 - 60 min prior to the induction of anesthesia.</li>
	<li>Let the patient be monitored according to standard guidelines, with direct arterial and central venous pressure access by the anesthesiologists. Induce anesthesia using an initial intravenous injection of 0.5 - 1.5 mg/kg propofol, 1 - 2 &#181;g/kg fentanyl, and 0.6 mg/kg rocuronium.</li>
	<li>Perform tracheal intubation and maintain the anesthesia through the intravenous infusion of 100 - 150 &#181;g/kg/min propofol, 0.015 - 0.03 &#181;g/kg/min fentanyl, and 0.6 - 1.2 &#181;g/kg/min rocuronium as needed.</li>
	<li>Install the patient in a supine position and drape her/him in a sterile fashion, leaving the chest, the abdomen, and the groin free in the operative field.</li>
</ol>
2. Surgery
<ol>
	<li>To minimize crowding of the operative field by cannulas, establish the cardio-pulmonary bypass access outside the thorax.
	<ol>
		<li>Perform a 6 cm-long incision 2 cm below and parallel to the right clavicle. Prepare the right subclavian artery, freeing it from the surrounding tissue. Give 300 I.U. of heparin/kg through the IV line.</li>
		<li>Side-clamp the right subclavian artery with a Cooley Derra clamp. Perform a 10 mm-long arteriotomy of the vessel parallel to its axis.</li>
		<li>Sew an 8-mm Dacron graft end-to-end to the arteriotomy using a running 6/0 polypropylene monofilament suture (e.g., Prolene). Cannulate the graft with a 24 Fr elongated one-piece arterial cannula for arterial return to the patient.</li>
		<li>Under transesophageal echocardiographic guidance, cannulate the right femoral vein percutaneously over a guidewire for venous drainage.</li>
	</ol>
	</li>
	<li>Access the heart through a median sternotomy.
	<ol>
		<li>Incise the skin longitudinally over 15 cm, starting 1 cm below the suprasternal notch. Take care to stay in the middle of the sternal width.</li>
		<li>Saw the sternum with an oscillatory saw. Take care to stay in the middle of the sternal width.</li>
		<li>Incise the pericardium over the aorta to uncover the massively dilated and tortuous right coronary artery.
		<ol>
			<li>Grab the pericardium with Carpentier dissection forceps. Cut the pericardium with Metzenbaum scissors. Continue cutting the pericardium up to its reflection line over the ascending aorta using electrocautery.</li>
		</ol>
		</li>
		<li>Start the extra-corporeal circulation and dissect the aorta circumferentially, freeing it from the surrounding tissue, including the pulmonary artery, taking care not to injure the anomalous left coronary artery.
		<ol>
			<li>Gently push the ascending aorta to the left using a lung retractor. Grab the soft tissue behind the ascending aorta with Carpentier dissection forceps.</li>
			<li>Separate the posterior wall of the ascending aorta from the surrounding tissue using electrocautery. Continue caudally behind the ascending aorta. Make sure not to injure the right pulmonary artery behind the ascending aorta.</li>
			<li>Grab the main pulmonary artery with Carpentier dissection forceps and push it gently towards the left side. Separate the left lateral wall of the ascending aorta from the main pulmonary artery using electrocautery.</li>
		</ol>
		</li>
		<li>Dissect the main pulmonary artery free from the surrounding tissue.
		<ol>
			<li>Pull the ascending aorta towards the right side using a peanut gauze mounted on an Allis clamp.</li>
			<li>Bluntly dissect the posterior wall of the main pulmonary artery with a second peanut gauze mounted on an Allis clamp. Make sure not to injure the main left coronary artery behind the main pulmonary artery.</li>
			<li>Pass a dissector under the main pulmonary artery. Gently open the dissector to prepare a tunnel for the passage of the vessel loop.</li>
			<li>Bring down a vessel loop mounted on Carpentier dissection forceps and place it between the open jaws of the dissector. Close the jaws of the dissector to grab the vessel loop.</li>
			<li>Grab the adventitia of the ascending aorta and pull the vessel loop held by the dissector to encircle the main pulmonary artery.</li>
		</ol>
		</li>
		<li>Place a left ventricular vent.
		<ol>
			<li>Place a purse-string on the right upper pulmonary vein with a 4/0 polypropylene monofilament suture.</li>
			<li>Gently push the superior vena cava towards the left side.</li>
			<li>Make a small cut in the middle of the purse-string on the right upper pulmonary vein with an 18-blade knife (see the Materials List).</li>
			<li>Gently dilate the opening with a Leriche hemostatic clamp.</li>
			<li>Insert a vent through the right upper pulmonary vein and the mitral valve into the left ventricle to unload the left heart. Secure it with a braided polyester 2/0 ligature with polybutylene coating.</li>
		</ol>
		</li>
		<li>Place a retrograde cardioplegic cannula through the coronary sinus. Secure it with a braided polyester 2/0 ligature with a polybutylene coating.</li>
		<li>Install the antegrade cardioplegic root.
		<ol>
			<li>Place a purse-string on the main pulmonary artery with a 4/0 polypropylene monofilament suture.</li>
			<li>Make a small cut in the middle of the purse-string on the main pulmonary artery with an 18-blade knife (see the Materials List).</li>
			<li>Gently dilate the opening with a Leriche hemostatic clamp. Insert an antegrade cardioplegic cannula in the main pulmonary artery. Secure it with a braided polyester 2/0 ligature with polybutylene coating.</li>
			<li>Place a purse-string on the ascending aorta with a 4/0 polypropylene monofilament suture.</li>
			<li>Make a small cut in the middle of the purse-string on the ascending aorta with an 18-blade knife.</li>
			<li>Gently dilate the opening with a Leriche hemostatic clamp.</li>
			<li>Insert an antegrade cardioplegic cannula into the ascending aorta. Secure it with a braided polyester 2/0 ligature with polybutylene coating. Cut the ligature with Metzenbaum scissors. Verify the correct placement of the antegrade cardioplegic cannulas in the main pulmonary artery and ascending aorta.</li>
		</ol>
		</li>
	</ol>
	</li>
	<li>Prepare to open the aorta.
	<ol>
		<li>Cross-clamp the aorta as distally as possible. Deliver the antegrade cold blood cardioplegia simultaneously through the aorta and the pulmonary artery.</li>
		<li>Remove the cannulas from the aorta and the pulmonary artery and repeat the cold blood cardioplegia retrogradely every 20 min.</li>
		<li>Transect the aorta.
		<ol>
			<li>Grab the ascending aorta with Carpentier dissection forceps on each side of the opening left following the removal of the cardioplegic cannula. Enlarge the opening with an 18-blade knife.</li>
			<li>Finish the transection of the aorta with Metzenbaum scissors. Verify the absence of the left coronary ostium inside the aorta in the left sinus of Valsalva.</li>
		</ol>
		</li>
		<li>Transect the main pulmonary artery.
		<ol>
			<li>Grab the main pulmonary artery with Carpentier dissection forceps on each side of the opening left following the removal of the cardioplegic cannula. Enlarge the opening with an 18-blade knife.</li>
			<li>Finish the transection of the main pulmonary artery with Metzenbaum scissors. Confirm the presence of the left coronary ostium, originating from the right-facing sinus 110 of the pulmonary artery.</li>
		</ol>
		</li>
		<li>Detach the left coronary ostium from the right-facing sinus 1 of the pulmonary artery.
		<ol>
			<li>Grab the proximal main pulmonary artery with Carpentier dissection forceps. Using Metzenbaum scissors, separate the left coronary ostium from the right-facing sinus 1 of the pulmonary artery with a generous surrounding patch of the pulmonary root wall, taking care not to injure the pulmonary valve.</li>
			<li>Mobilize the main left coronary artery up to its bifurcation.</li>
		</ol>
		</li>
	</ol>
	</li>
	<li>Prepare for the re-implantation of the left coronary ostium.
	<ol>
		<li>Grab the proximal ascending aorta with Carpentier dissection forceps.</li>
		<li>Use a straight blade to create a neo-ostium in the left sinus 2 of the aorta. Leave a 10-mm margin of aortic root wall around the neo-ostium towards the commissure between the left sinus 2 and the right coronary sinus of the aorta, as well as towards the aortic annulus.</li>
		<li>Connect the main left coronary ostium end-to-end to the neo-ostium in the left sinus 2 of the aorta using a running 6/0 polypropylene monofilament suture. Start the anastomosis at the deepest point of the main left coronary ostium and allow it to come up on the right-hand side of the anastomosis. Complete the anastomosis by running the left-hand side of the suture to meet the other end.</li>
		<li>To relieve tension on the tissue when pulling the sutures, bring the aorta and the main left coronary ostium together each time.</li>
	</ol>
	</li>
	<li>Repair the defect in the pulmonary artery root.
	<ol>
		<li>Use a non-treated autologous pericardial patch.</li>
		<li>Connect the autologous pericardial patch at the deepest point of the right-facing sinus 1 of the pulmonary artery using a running 6/0 polypropylene monofilament suture.</li>
		<li>First run up the left and then the right end of the suture to mid-height of the defect in the right-facing sinus 1 of the pulmonary artery. Leave the two ends of the suture under tension.</li>
	</ol>
	</li>
	<li>Reestablish the continuity of the great vessels.
	<ol>
		<li>Reconnect the proximal part of the aorta to its distal part with an end-to-end anastomosis using a running 5/0 polypropylene monofilament suture. Start the anastomosis at the deepest point, allowing it to come up on the right-hand side of the anastomosis. Complete the anastomosis by running the left-hand side of the suture to meet the other end.</li>
		<li>De-air the aorta. Remove the aortic cross-clamp. Start rewarming the patient.</li>
		<li>To shorten the ischemic time, perform the reconnection of the proximal and distal parts of the pulmonary artery on the beating heart. Put the pump sucker into the distal pulmonary artery to improve the sight of the operative field.</li>
		<li>Continue in a running fashion the left end of the 6/0 polypropylene suture that had been stopped at mid-height of the defect in the right-facing sinus 1 of the pulmonary artery to complete the posterior and left aspects of the anastomose.</li>
		<li>Continue in a running fashion the right end of the 6/0 polypropylene suture that had been stopped at mid-height of the defect in the right-facing sinus 1 of the pulmonary artery to complete the posterior and right aspects of the anastomose. Tie the two ends of the suture to finish the connection.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Dodge-Khatami, A., Mavroudis, C., Backer, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anomalous+origin+of+the+left+coronary+artery+from+the+pulmonary+artery:+collective+review+of+surgical+therapy.">Anomalous origin of the left coronary artery from the pulmonary artery: collective review of surgical therapy.</a> Ann. Thorac. Surg. 74 (3), 946-955 (2002).</li><li>Keith, J. 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+anomalous+origin+of+the+left+coronary+artery+from+the+pulmonary+artery.">The anomalous origin of the left coronary artery from the pulmonary artery.</a> Br. Heart J. 21 (2), 149-161 (1959).</li><li>Hauser, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Congenital+anomalies+of+the+coronary+arteries.">Congenital anomalies of the coronary arteries.</a> Heart. 91 (9), 1240-1245 (2005).</li><li>Wesselhoeft, H., Fawcett, J. S., Johnson, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anomalous+origin+of+the+left+coronary+artery+from+the+pulmonary+trunk.+Its+clinical+spectrum,+pathology,+and+pathophysiology,+based+on+a+review+of+140+cases+with+seven+further+cases.">Anomalous origin of the left coronary artery from the pulmonary trunk. Its clinical spectrum, pathology, and pathophysiology, based on a review of 140 cases with seven further cases.</a> Circulation. 38 (2), 403-425 (1968).</li><li>Edwards, J. 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M., Banbury, T., Mehta, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+rare+case+of+anomalous+left+coronary+artery+from+the+pulmonary+artery+(Bland-White-Garland+Syndrome)+in+a+68-year-old+woman.">A rare case of anomalous left coronary artery from the pulmonary artery (Bland-White-Garland Syndrome) in a 68-year-old woman.</a> Semin. Cardiothorac. Vasc. Anesth. , (2016).</li><li>Yau, J. M., Singh, R., Halpern, E. J., Fischman, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anomalous+origin+of+the+left+coronary+artery+from+the+pulmonary+artery+in+adults:+a+comprehensive+review+of+151+adult+cases+and+a+new+diagnosis+in+a+53-year-old+woman.">Anomalous origin of the left coronary artery from the pulmonary artery in adults: a comprehensive review of 151 adult cases and a new diagnosis in a 53-year-old woman.</a> Clin. Cardiol. 34 (4), 204-210 (2011).</li><li>Michielon, G., 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=Anomalous+coronary+artery+origin+from+the+pulmonary+artery:+correlation+between+surgical+timing+and+left+ventricular+function+recovery.">Anomalous coronary artery origin from the pulmonary artery: correlation between surgical timing and left ventricular function recovery.</a> Ann. Thorac. Surg. 76 (2), 581-588 (2003).</li><li>Dodge-Khatami, A., Mavroudis, C., Backer, C. 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+Surgery+Nomenclature+and+Database+Project:+anomalies+of+the+coronary+arteries.">Congenital Heart Surgery Nomenclature and Database Project: anomalies of the coronary arteries.</a> Ann. Thorac. Surg. 69 (4 Suppl), S270-S297 (2000).</li><li>Talwar, S., Jha, A. J., Choudhary, S. K., Gupta, S. K., Airan, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Repair+of+anomalous+left+coronary+artery+from+pulmonary+artery+(ALCAPA)+beyond+infancy.">Repair of anomalous left coronary artery from pulmonary artery (ALCAPA) beyond infancy.</a> Heart Surg. Forum. 16 (4), E210-E215 (2013).</li><li>Toumpourleka, M., Belitsis, G., Alonso, R., Rubens, M., Moat, N., Gatzoulis, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Late+presentation+and+surgical+repair+of+ALCAPA.">Late presentation and surgical repair of ALCAPA.</a> Int. J. Cardiol. 186, 207-209 (2015).</li><li>Quah, J. X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+management+of+the+older+adult+patient+with+anomalous+left+coronary+artery+from+the+pulmonary+artery+syndrome:+a+presentation+of+two+cases+and+review+of+the+literature.">The management of the older adult patient with anomalous left coronary artery from the pulmonary artery syndrome: a presentation of two cases and review of the literature.</a> Congenit. Heart Dis. 9 (6), E185-E194 (2014).</li><li>Kottayil, B. P., 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=Anomalous+origin+of+left+coronary+artery+from+pulmonary+artery+in+older+children+and+adults:+direct+aortic+implantation.">Anomalous origin of left coronary artery from pulmonary artery in older children and adults: direct aortic implantation.</a> Ann. Thorac. Surg. 91 (2), 549-553 (2011).</li><li>Rajbanshi, B. G., Burkhart, H. M., Schaff, H. V., Daly, R. C., Phillips, S. D., Dearani, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surgical+strategies+for+anomalous+origin+of+coronary+artery+from+pulmonary+artery+in+adults.">Surgical strategies for anomalous origin of coronary artery from pulmonary artery in adults.</a> J. Thorac. Cardiovasc. Surg. 148 (1), 220-224 (2014).</li><li>Neumann, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+results+after+repair+of+anomalous+origin+of+left+coronary+artery+from+the+pulmonary+artery:+Takeuchi+repair+versus+coronary+transfer.">Long-term results after repair of anomalous origin of left coronary artery from the pulmonary artery: Takeuchi repair versus coronary transfer.</a> Eur. J. Cardio-Thorac. Surg. , (2016).</li><li>Pe&#241;a, E., Nguyen, E. T., Merchant, N., Dennie, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ALCAPA+syndrome:+not+just+a+pediatric+disease.">ALCAPA syndrome: not just a pediatric disease.</a> Radiographics. 29 (2), 553-565 (2009).</li></ol>

The authors have nothing to disclose.

This protocol describes a detailed technique for the direct re-implantation of the ALCAPA into the aorta in an adult patient with the origin of main left coronary artery from the right-facing sinus of the pulmonary artery according to the Dodge-Khatami classification10. The myocardial protection strategy and the reconstruction of the pulmonary artery are clearly demonstrated. The major critical step of this technique is represented by the generous mobilization of the left coronary artery to achieve a tension-free anastomosis.
Prolonged desaturated coronary perfusion is tolerated into adulthood in a small number of individuals. ALCAPA patients who survive to adulthood present with a spectrum of clinical manifestations, ranging from the absence of symptoms to acute myocardial infarction and/or chronic myocardial ischemia8. The latter would ultimately lead to left ventricular dysfunction, ischemic mitral regurgitation, malignant ventricular arrhythmias, and sudden cardiac death7. Therefore, surgical correction is highly recommended as soon as the diagnosis is made, regardless of age or the degree of intercoronary collateralization1,9.
In both adults and infants, the direct re-implantation of the ALCAPA represents the physiological repair method and is the preferred technique when the anatomy is suitable1. However, in adults, the direct re-implantation of the ALCAPA might be more challenging because of a very short main left coronary artery, increased coronary artery friability, diminished vessel elasticity for mobilization, and the potential for tearing and the resultant uncontrollable bleeding14,15. In these situations, coronary artery bypass grafting associated with the ligation of the ALCAPA may be more suitable11,12,13. In a series of 30 patients with ALCAPA, 3 of which were adults, Neumann et al. performed 19 direct re-implantations, 9 Takeuchi repairs, and 2 ligations16. The early and late 24-year survival rates for direct re-implantation were both 100%, and the 10-year rate of freedom from reoperation was 94.1%16. At the last follow-up, 95.5% of the patients were in New York Heart Association functional class I16.
Other options for surgical repair aim to prevent the coronary steal phenomenon and, ideally, to restore dual-coronary circulation. The simplest corrective procedure involves ligating the LMCA, which does prevent steal, but does not allow for antegrade flow into the left-sided circulation. Therefore, this is most often combined with bypass grafting11,12. This approach, less physiological than the previous, is generally the most straightforward in adults, but there remains a risk of late graft stenosis, especially with saphenous vein grafts13. In adults, creating an intrapulmonary baffle (Takeuchi procedure) is a more complex option that does restore the dual-coronary supply but that may be complicated by supravalvular pulmonary stenosis and baffle obstruction or leakage13,17.
The treatment of associated ischemic mitral valve regurgitation remains controversial and depends on the degree, as well as the functional versus structural type, of regurgitation. The age of the patient, the personal experience of the surgeon, and the ability of the center must also be considered. In infants, most authors recommend an expectative approach, unless the mitral regurgitation is severe1,16. In adults, the decision on the concomitant surgical correction of functional ischemic mitral regurgitation during the operation for ALCAPA should be made with regard to the severity of the mitral regurgitation and the possibility for it to worsen after intra-operative norepinephrine tests. An aggravation of mitral regurgitation following norepinephrine challenge, evidenced by intra-operative transesophageal echocardiography, would support the correction of the mitral regurgitation. For structural mitral regurgitation, correction would be recommended for more than mild regurgitation, unless the prolongation of the cross-clamp time is deemed undesirable for the patient.
In conclusion, in adult-type ALCAPA originating from the right-facing sinus of the pulmonary artery, direct re-implantation into the aorta is recommended, provided that the tissue is of adequate elastic quality. Thickening and calcification of the main left coronary could be detected in the pre-operative computed tomography. However, the final evaluation of the tissue elasticity is performed by intra-operative visual inspection and gentle palpation of the vessel wall for the absence of calcified plaques and by the tactile perception of tissue resistance during mobilization.

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital anomaly usually seen as an isolated lesion1. The incidence of ALCAPA is estimated at 1 in 300,000 live births, comprising between 0.24% and 0.46% of congenital cardiac diseases2,3. It is one of the most common causes of myocardial ischemia and infarction in children and, if left untreated, results in a 90% mortality rate in the first year of life4. Only 10 - 15% of infants survive to adulthood due to the rapid development of a large dominant right coronary artery (RCA) with extensive intercoronary collaterals4. During the neonatal period, high pulmonary vascular resistance and the resultant pulmonary artery (PA) pressures ensure that antegrade flow is&#160;maintained from the PA into the anomalous left coronary artery. As the pulmonary vascular resistance gradually decreases, antegrade flow to the left coronary artery reduces. This eventually leads to reversal of flow, and left-to-right shunting into the PA, thus resulting in a &#34;coronary steal5.&#34; Thus, left ventricular (LV) myocardial perfusion depends on intercoronary collaterals from an RCA5,6.
The coronary steal phenomenon and retrograde left-sided coronary flow provide a substrate for chronic subendocardial ischemia, which may lead to left ventricular dysfunction, ischemic mitral regurgitation, and malignant ventricular arrhythmias precipitated by acute myocardial ischemia7. In a subset of adult patients, the mean age at presentation is 41 years, with a shift in sex distribution toward female patients (Female-to-male ratio: 2:1)8. In this patient population, 14% are asymptomatic; 66% present with symptoms of angina, dyspnea, palpitations, or fatigue; and 17% present with life-threatening symptoms, including ventricular arrhythmias, syncope, and sudden cardiac death8. The average age of life-threatening presentation is 33 years and of sudden cardiac death 31 years8. Therefore, surgical correction is highly recommended as soon as the diagnosis is made, regardless of age or the degree of intercoronary collateralization1,9.
Depending on the origin of the anomalous left coronary artery, direct re-implantation of the ALCAPA into the aorta is the more physiologically sound repair technique to reestablish the dual-coronary perfusion system. Most commonly, ALCAPA takes off from the right-hand pulmonary sinus (sinus 1 of the PA), which faces the aortic sinus where the main left coronary artery usually originates (sinus 2 of the aorta)10. This coronary anatomy is most suited to the direct re-implantation technique. The aim of this report is to describe, in detail, the technique for the direct re-implantation of the left coronary artery in ALCAPA in adult patients. The rationale behind direct re-implantation is the advantage-the physiological reestablishment of dual-coronary perfusion-it offers over the ligation of the anomalous left coronary combined with coronary artery bypass grafting11,12,13.

<table><tbody><tr><td colspan="4">&lt;strong&gt;Heart surgery infrastructure&lt;/strong&gt;</td></tr><tr><td>Heart Lung Machine</td><td>Stockert</td><td>SIII</td><td></td></tr><tr><td>EOPA 24Fr. arterial cannula</td><td>Medtronic</td><td>77624</td><td></td></tr><tr><td>Quickdraw 25Fr. femoral venous cannula</td><td>Edwards</td><td>QD25</td><td></td></tr><tr><td>LV vent catheter 17Fr.</td><td>Edwards</td><td>E061</td><td></td></tr><tr><td>Antegrade 9Fr. cardioplegia cannula</td><td>Edwards</td><td>AR012V</td><td></td></tr><tr><td>Retrograde 14Fr. cardioplegia cannula&amp;nbsp;</td><td>Edwards</td><td>NPC014&amp;nbsp;</td><td></td></tr><tr><td>Electrocautery</td><td>Covidien</td><td>Force FX</td><td></td></tr><tr><td colspan="4">&lt;strong&gt;Sutures&lt;/strong&gt;</td></tr><tr><td>Polypropylene 4/0</td><td>Ethicon</td><td>8871H</td><td></td></tr><tr><td>Polypropylene 5/0</td><td>Ethicon</td><td>8870H</td><td></td></tr><tr><td>Polypropylene 6/0</td><td>Ethicon</td><td>EH7400H</td><td></td></tr><tr><td>Braided polyesther 2/0 ligature with polybutylate coating&amp;nbsp;</td><td>Ethicon</td><td>X305H</td><td></td></tr><tr><td>Intergard dacron graft 8 mm</td><td>Maquet</td><td>IGW0008-30</td><td></td></tr><tr><td>Micro knife Sharpoint&amp;nbsp;</td><td>TYCO Healthcare PTY&amp;nbsp;</td><td>78-6900</td><td></td></tr><tr><td colspan="4">&lt;strong&gt;Drugs&lt;/strong&gt;</td></tr><tr><td>Midazolam</td><td>Roche Pharma</td><td>N05CD08</td><td></td></tr><tr><td>Rocuronium</td><td>&lt;a href=&quot;https://www.compendium.ch/comp/mnr/22695/de&quot;&gt;MSD Merck Sharp &amp;amp; Dohme&amp;nbsp;&lt;/a&gt;</td><td>M03AC09</td><td></td></tr><tr><td>Propofol</td><td>Fresenius Kabi</td><td>N01AX10</td><td></td></tr><tr><td>Fentanil</td><td>Actavis</td><td>N01AH01</td><td></td></tr><tr><td colspan="4">&lt;strong&gt;Instruments&lt;/strong&gt;</td></tr><tr><td>Cooley Derra anastomosis clamp</td><td>Delacroix-Chevalier</td><td>DC40810-16</td><td></td></tr><tr><td>Cooley vascular clamp</td><td>Delacroix-Chevalier</td><td>DC40810-16</td><td></td></tr><tr><td>Dissection forceps Carpentier</td><td>Delacroix-Chevalier</td><td>DC13110-28&amp;nbsp;</td><td></td></tr><tr><td>Scissors Metzenbaum</td><td>Delacroix-Chevalier</td><td>B351751</td><td></td></tr><tr><td>Needle holder Ryder</td><td>Delacroix-Chevalier</td><td>DC51130-20&amp;nbsp;</td><td></td></tr><tr><td>Dissection forceps DeBakey</td><td>Delacroix-Chevalier</td><td>DC12000-21&amp;nbsp;</td><td></td></tr><tr><td>Micro needle holder Jacobson</td><td>Delacroix-Chevalier</td><td>DC50002-21&amp;nbsp;</td><td></td></tr><tr><td>Micro scisors Jacobson</td><td>Delacroix-Chevalier</td><td>DC20057-21&amp;nbsp;</td><td></td></tr><tr><td>Lung retractor</td><td>Delacroix-Chevalier</td><td>B803990</td><td></td></tr><tr><td>Allis clamp</td><td>Delacroix-Chevalier</td><td>DC45907-25&amp;nbsp;</td><td></td></tr><tr><td>O&amp;rsquo;Shaugnessy Dissector</td><td>Delacroix-Chevalier</td><td>B60650</td><td></td></tr><tr><td>Vessel loop</td><td>Medline</td><td>VLMINY</td><td></td></tr><tr><td>18 blade knife</td><td>Delacroix-Chevalier</td><td>B130180</td><td></td></tr><tr><td>Leriche haemostatic clamp</td><td>Delacroix-Chevalier</td><td>B86555</td><td></td></tr></tbody></table>

direct re-implantation of left coronary artery into the aorta in adults with anomalous origin of left coronary artery from the pulmonary artery (alcapa)

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital anomaly which is one of leading causes of myocardial ischemia and infarction in children. If left untreated, it results in a 90% mortality rate in the first year of life. In patients who survive to the adulthood, the coronary steal phenomenon and retrograde left-sided coronary flow provide a substrate for chronic subendocardial ischemia, which may lead to left ventricular dysfunction, ischemic mitral regurgitation, malignant ventricular arrhythmias, and sudden cardiac death. The average age of life-threatening presentation is 33 years and of sudden cardiac death 31 years. Therefore, surgical correction is highly recommended as soon as the diagnosis is made, regardless of age. In adult-type ALCAPA originating from the right-facing sinus of the pulmonary artery, direct re-implantation of the ALCAPA into the aorta is the more physiologically sound repair technique to re-establish the dual-coronary perfusion system and is recommended. This protocol describes the technique of direct re-implantation of adult-type ALCAPA into the aorta.

Presentation
The patient was a 48-year-old woman presenting with the recent onset of angina Canadian Cardiovascular Society (CCS) grad III and occasional palpitations. She reported three uneventful pregnancies. Moderate smoking was the main cardiovascular risk factor. Trans-thoracic echocardiography showed a moderately impaired (45%) left ventricular ejection fraction and no mitral regurgitation. A coronary angiography was then performed. It demonstrated the absence of the left main coronary artery arising from the aorta. The right coronary artery was considerably enlarged and perfused the main left coronary artery via intraseptal collaterals (Figure 1). Thus, the diagnosis of ALCAPA was made. The anatomical type of ALCAPA was further defined by bi-plan (Figure 2) and three-dimensional (Figure 3) CT scans.
Post-operative Course
The patient was separated from the cardiopulmonary bypass at a core temperature of 37 °C. No post-operative myocardial ischemia occurred. Bleeding from the chest tube drain was less than 30 mL/h. The patient was weaned from the ventilator and extubated 6 h post-operatively. She was discharged from the intensive care unit to the normal ward on the first post-operative day. Her course on the ward remained uneventful; she was discharged to a cardiac rehabilitation program on post-operative day 9.
One-year Follow-up
The patient was seen at the outpatient clinic one year after surgery. She was working full-time and had no angina or dyspnea. Her exercise test was negative. Figure 4 shows her CT scan one year after surgery. The re-implanted ALCAPA is widely patent at the site of anastomosis to the aorta. The pulmonary artery does not present any narrowing at the site of reconstruction with the autologous pericardial patch used to repair the defect in the right-facing sinus of the PA.
<img alt="Coronary angiography X-ray and diagram; RCA, PA, LCA, LAD, CX arteries labeled for cardiac study." src="/files/ftp_upload/55590/55590fig1.jpg" data-altupdatedat="1747911167000" data-alt="Figure 1"> 
Figure 1: Pre-operative Coronary Angiography. A) The coronary angiography of the patient is remarkable for the absence of the ostium of the main left coronary artery (LCA) in the aorta. In a right anterior oblique view, the opacified right coronary artery (RCA) is considerably enlarged, measuring 12 mm. It follows a tortuous path across the right heart while supplying large collaterals to the left-sided circulation via intraseptal collateral vessels (yellow arrows). These collaterals feed the left anterior descending (LAD) and left circumflex (CX) arteries, which join the main left coronary artery and drain in a retrograde fashion into the main pulmonary artery (PA). B) This diagram shows a schematic representation of the normal distribution of the coronary arteries. (1 mm on figure scale = 2 mm) <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55590/55590fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="CT scan showing ALCAPA condition; labeled aorta and PA; coronary anomaly diagnosis." src="/files/ftp_upload/55590/55590fig2.jpg" data-altupdatedat="1747911167000" data-alt="Figure 2"> 
Figure 2: Pre-operative Computed Tomography. A cardiac computed tomography scan shows the take-off of the ALCAPA from the right-facing sinus of the PA according to the Dodge-Khatami classification10. (1 mm on figure scale = 2.14 mm)
<img alt="3D CT coronary artery visualization; left from pulmonary artery, right from aorta, anatomical diagram." src="/files/ftp_upload/55590/55590fig3.jpg" data-altupdatedat="1747911167000" data-alt="Figure 3"> 
Figure 3: Pre-operative Three-dimensional Computed Tomography. A three-dimensional reconstruction of the computed tomography of the great vessels confirms the topography of the ALCAPA originating from the right-facing sinus 1 of the PA and the RCA from the facing sinus 1 of the aorta10. From this anatomy, a direct translocation of the ALCAPA to the aorta seems feasible. (1 mm on figure scale = 1.66 mm) <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55590/55590fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Heart CT scan showing pre- and post-operative ALCAPA; highlighting aorta and pulmonary artery." src="/files/ftp_upload/55590/55590fig4.jpg" data-altupdatedat="1747911167000" data-alt="Figure 4"> 
Figure 4: Follow-up Post-operative Computed Tomography. In the right panel, the computed tomography scan of the patient one year after surgery shows a widely patent main left coronary artery (ALCAPA) connected to the aorta. The reconstructed pulmonary artery (PA) does not present any narrowing. In the left panel, the pre-operative computed tomography depicts the ALCAPA originating from the right-facing sinus of the PA according to the Dodge-Khatami classification10. (1 mm on figure scale = 2.14 mm in the left panel, 1 mm on figure scale = 2.5 mm in the right panel) <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55590/55590fig4large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Watch this Scientific Journal Video about Direct Re-implantation of Left Coronary Artery into the Aorta in Adults with Anomalous Origin of Left Coronary Artery from the Pulmonary Artery ALCAPA at JoVE

Direct Re-implantation of Left Coronary Artery into the Aorta in Adults with Anomalous Origin of Left Coronary Artery from the Pulmonary Artery ALCAPA

Surgical correction of ALCAPA is highly recommended, regardless of age or the degree of intercoronary collateralization. This protocol presents a technique for the direct re-implantation of adult-type ALCAPA into the aorta to re-establish the dual-coronary perfusion. Whenever feasible, direct re-implantation is preferred to other surgical correction techniques.

Direct Re-implantation of Left Coronary Artery into the Aorta in Adults with Anomalous Origin of Left Coronary Artery from the Pulmonary Artery (ALCAPA)

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital anomaly which is one of leading causes of myocardial ...

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Nanyang Technological University

Research

JoVE Journal

Medicine

18.5K Views.  University of Zurich.  Chirurgische correctie van ALCAPA wordt sterk aanbevolen, ongeacht leeftijd of de mate van intercoronary collateralization. Dit protocol geeft een techniek voor het direct herimplantatie volwassen type ALCAPA in de aorta om opnieuw de dubbele coronaire perfusie. Waar mogelijk, is directe reïmplantatie voorkeur andere chirurgische correctie technieken. 

Video: Direct Re-implantation of Left Coronary Artery into the Aorta in Adults with Anomalous Origin of Left Coronary Artery from the Pulmonary Artery ALCAPA

A Murine Model of Myocardial Ischemia-reperfusion Injury through Ligation of the Left Anterior Descending Artery

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms at work during MI and developing effective therapeutic approaches requires methodology to reproducibly simulate the clinical incidence and reflect the pathophysiological changes associated with MI. Here, we describe a surgical method to induce MI in mouse models that can be used for short-term ischemia-reperfusion (I/R) injury as well as permanent ligation. The major advantage of this method is to facilitate location of the left anterior descending artery (LAD) to allow for accurate ligation of this artery to induce ischemia in the left ventricle of the mouse heart. Accurate positioning of the ligature on the LAD increases reproducibility of infarct size and thus produces more reliable results. Greater precision in placement of the ligature will improve the standard surgical approaches to simulate MI in mice, thus reducing the number of experimental animals necessary for statistically relevant studies and improving our understanding of the mechanisms producing cardiac dysfunction following MI. This mouse model of MI is also useful for the preclinical testing of treatments targeting myocardial damage following MI.

We introduce a surgical method to induce experimental ischemia/reperfusion (I/R) injury to simulate myocardial infarction (MI) in mouse models that allows for more clarity in positioning of the ligation on the left anterior descending artery (LAD) to increase the reproducibility of MI experiments in mice.

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms ...

Permanent Ligation of the Left Anterior Descending Coronary Artery in Mice: A Model of Post-myocardial Infarction Remodelling and Heart Failure

Heart failure is a syndrome in which the heart fails to pump blood at a rate commensurate with cellular oxygen requirements at rest or during stress. It is characterized by fluid retention, shortness of breath, and fatigue, in particular on exertion. Heart failure is a growing public health problem, the leading cause of hospitalization, and a major cause of mortality. Ischemic heart disease is the main cause of heart failure.
Ventricular remodelling refers to changes in structure, size, and shape of the left ventricle. This architectural remodelling of the left ventricle is induced by injury (e.g., myocardial infarction), by pressure overload (e.g., systemic arterial hypertension or aortic stenosis), or by volume overload. Since ventricular remodelling affects wall stress, it has a profound impact on cardiac function and on the development of heart failure. A model of permanent ligation of the left anterior descending coronary artery in mice is used to investigate ventricular remodelling and cardiac function post-myocardial infarction. This model is fundamentally different in terms of objectives and pathophysiological relevance compared to the model of transient ligation of the left anterior descending coronary artery. In this latter model of ischemia/reperfusion injury, the initial extent of the infarct may be modulated by factors that affect myocardial salvage following reperfusion. In contrast, the infarct area at 24 hr after permanent ligation of the left anterior descending coronary artery is fixed. Cardiac function in this model will be affected by 1) the process of infarct expansion, infarct healing, and scar formation; and 2) the concomitant development of left ventricular dilatation, cardiac hypertrophy, and ventricular remodelling.
Besides the model of permanent ligation of the left anterior descending coronary artery, the technique of invasive hemodynamic measurements in mice is presented in detail.

Heart failure is the leading cause of hospitalization and a major cause of mortality. A model of permanent ligation of the left anterior descending coronary artery in mice is applied to investigate ventricular remodelling and cardiac dysfunction post-myocardial infarction. The technique of invasive hemodynamic measurements in mice is presented.

Heart failure is a syndrome in which the heart fails to pump blood at a rate commensurate with cellular oxygen requirements at rest or during stress. It ...

Transplantation of a 3D Bioprinted Patch in a Murine Model of Myocardial Infarction

Testing regenerative properties of 3D bioprinted cardiac patches in vivo using murine models of heart failure via permanent left anterior descending (LAD) ligation is a challenging procedure and has a high mortality rate due to its nature. We developed a method to consistently transplant bioprinted patches of cells and hydrogels onto the epicardium of an infarcted mouse heart to test their regenerative properties in a robust and feasible way. First, a deeply anesthetized mouse is carefully intubated and ventilated. Following left lateral thoracotomy (surgical opening of the chest), the exposed LAD is permanently ligated and the bioprinted patch transplanted onto the epicardium. The mouse quickly recovers from the procedure after chest closure. The advantages of this robust and quick approach include a predicted 28-day mortality rate of up to 30% (lower than the 44% reported by other studies using a similar model of permanent LAD ligation in mice). Moreover, the approach described in this protocol is versatile and could be adapted to test bioprinted patches using different cell types or hydrogels where high numbers of animals are needed to optimally power studies. Overall, we present this as an advantageous approach which may change preclinical testing in future studies for the field of cardiac regeneration and tissue engineering.

This protocol aims to transplant a 3D bioprinted patch onto the epicardium of infarcted mice modeling heart failure. It includes details regarding anesthesia, the surgical chest opening, permanent ligation of the left anterior descending (LAD) coronary artery and application of a bioprinted patch onto the infarcted area of the heart.

Testing regenerative properties of 3D bioprinted cardiac patches in vivo using murine models of heart failure via permanent left anterior descending (LAD) ...

Bioengineering

Full-root Aortic Valve Replacement by Stentless Aortic Xenografts in Patients with Small Aortic Roots

In patients with small aortic roots who need an aortic valve replacement with biological valve substitutes, the implantation of the stented pericardial valve might not meet the functional needs. The implantation of a too-small stented pericardial valve, leading to an effective orifice area indexed to a body surface area less than 0.85 cm2/m2, is regarded as prosthesis-patient mismatch (PPM). A PPM negatively affects the regression of left ventricular hypertrophy and thus the normalization of left ventricular function and the alleviation of symptoms. Persistent left ventricular hypertrophy is associated with an increased risk of arrhythmias and sudden cardiac death. In the case of predictable PPM, there are three options: 1) accept the PPM resulting from the implantation of a stented pericardial valve when comorbidities of the patient forbid the more technically demanding operative technique of implanting a larger prosthesis, 2) enlarge the aortic root to accommodate a larger stented valve substitute, or 3) implant a stentless biological valve or a homograft. Compared to classical aortic valve replacement with stented pericardial valves, the full-root implantation of stentless aortic xenografts offers the possibility of implanting a 3-4 mm larger valve in a given patient, thus allowing significant reduction in transvalvular gradients. However, a number of cardiac surgeons are reluctant to transform a classical aortic valve replacement with stented pericardial valves into the more technically challenging full-root implantation of stentless aortic xenografts. Given the potential hemodynamic advantages of stentless aortic xenografts, we have adopted full-root implantation to avoid PPM in patients with small aortic roots necessitating an aortic valve replacement. Here, we describe in detail a technique for the full-root implantation of stentless aortic xenografts, with emphasis on the management of the proximal suture line and coronary anastomoses. Limitations of this technique and alternative options are discussed.

Full-root aortic valve replacement by stentless aortic xenograft is a viable option in patients with small aortic roots. We describe, a technique for the full-root implantation of stentless aortic xenografts, with emphasis on the management of the proximal suture line and coronary anastomoses, and discuss its limitations and alternative options.

In patients with small aortic roots who need an aortic valve replacement with biological valve substitutes, the implantation of the stented pericardial ...

Standardized Technique of Aortic Valve Re-implantation for Valve-sparing Aortic Root Replacement

Despite the obvious advantages of the preservation of a normal aortic valve during aortic root replacement, the complexity of valve sparing procedures prevents a number of cardiac surgeons from incorporating them into their practice. The aim of this protocol is to describe a simplified and user-friendly technique of an aortic valve-sparing root replacement (VSRR) procedure by re-implantation of the aortic valve. Proper selection of patients and limitations of the technique are discussed.
In 54 consecutive patients, normal appearing aortic valves were re-implanted in a commercially available polyester prosthesis with pre-shaped sinuses by a simplified and standardized technique. Placement of the first row of the proximal suture line, choice of the prosthesis size, and adjustment of the height of the commissures of the patient to the fixed height of the sinus portion of the prosthesis were slightly modified from the reference techniques with the aim of increasing its feasibility for use by other cardiac surgeons. Early mortality and morbidity as well as 5-year survival, freedom from aortic valve reoperation, and freedom from recurrent moderate regurgitation were collected in all patients.
Thirty-day mortality, re-sternotomy for bleeding, re-sternotomy for mediastinitis, and the incidence of stroke were very low, 1.8% for each (1 of 54). No patient required permanent pace-maker implantation. At 5 years, survival, freedom from aortic valve reoperation, and freedom from recurrent moderate regurgitation were 97.5%, 95.2%, and 91.6%, respectively.
Mid-term results of our standardized technique of re-implantation of the aortic valve for valve-sparing aortic root replacement are very good and compare with more complex techniques reported by experienced surgeons. By following the present protocol of the standardized re-implantation technique, a greater number of cardiac surgeons can perform this procedure with comparable good results.

Valve-sparing aortic root replacement has the advantage of preserving the patient&#39;s own aortic valve. The complexity of the reported techniques to date restricts their use to a limited number of cardiac surgeons. This protocol describes step-by-step a standardized technique reproducible by a greater number of cardiac surgeons.

Despite the obvious advantages of the preservation of a normal aortic valve during aortic root replacement, the complexity of valve sparing procedures ...

An Immunological Model for Heterotopic Heart and Cardiac Muscle Cell Transplantation in Rats

Heterotopic heart transplantation in rats has been a commonly used model for diverse immunological studies for more than 50 years. Several modifications have been reported since the first description in 1964. After 30 years of performing heterotopic heart transplantation in rats, we have developed a simplified surgical approach, which can be easily taught and performed without further surgical training or background.
After dissection of the ascending aorta and the pulmonary artery and ligation of superior and inferior caval and pulmonary veins, the donor heart is harvested and subsequently perfused with ice-cold saline solution supplemented with heparin. After clamping and incising the recipient abdominal vessels, the donor ascending aorta and pulmonary artery are anastomosed to the recipient abdominal aorta and inferior vena cava, respectively, using continuous running sutures.
Depending on different donor-recipient combinations, this model allows analyses of either acute or chronic rejection of allografts. The immunological significance of this model is further enhanced by a novel approach of in-ear injection of vital cardiac muscle cells and subsequent analysis of draining cervical lymphatic tissue.

We describe a model of heterotopic abdominal heart transplantation in rats, implying modifications of current strategies, which lead to a simplified surgical approach. Additionally, we describe a novel rejection model by in-ear injection of vital cardiac muscle cells, allowing further transplant immunological analyses in rats.

Heterotopic heart transplantation in rats has been a commonly used model for diverse immunological studies for more than 50 years. Several modifications ...

Immunology and Infection

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.

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

Left Lung Orthotopic Transplantation in a Juvenile Porcine Model for ESLP

Lung transplantation is the gold-standard treatment for end-stage lung disease, with over 4,600 lung transplantations performed worldwide annually. However, lung transplantation is limited by a shortage of available donor organs. As such, there is high waitlist mortality. Ex situ lung perfusion (ESLP) has increased donor lung utilization rates in some centers by 15%-20%. ESLP has been applied as a method to assess and recondition marginal donor lungs and has demonstrated acceptable short- and long-term outcomes following transplantation of extended criteria donor (ECD) lungs. Large animal (in vivo) transplantation models are required to validate ongoing in vitro research findings. Anatomic and physiologic differences between humans and pigs pose significant technical and anesthetic challenges. An easily reproducible transplant model would permit the&#160;in vivo&#160;validation of current ESLP strategies and the preclinical evaluation of various interventions designed to improve donor lung function. This protocol describes a porcine model of orthotopic left lung allotransplantation. This includes anesthetic and surgical techniques, a customized surgical checklist, troubleshooting, modifications, and the benefits and limitations of the approach.

This protocol describes a juvenile porcine model of orthotopic left lung allotransplantation designed for use with ESLP research. Focus is made on anesthetic and surgical techniques, as well as critical steps and troubleshooting.

Lung transplantation is the gold-standard treatment for end-stage lung disease, with over 4,600 lung transplantations performed worldwide annually. ...

Left Anterior Descending Coronary Artery Ligation for Ischemia-Reperfusion Research: Model Improvement via Technical Modifications and Quality Control

Coronary heart disease is the leading cause of death globally. Complete cessation of blood flow in coronary arteries causes ST-segment elevation myocardial infarction (STEMI), resulting in cardiogenic shock and fatal arrhythmia, which are associated with high mortality. Primary coronary intervention (PCI) for recanalizing the coronary artery significantly improves the outcomes of STEMI, but advancements made in shortening the door-to-balloon time have failed to reduce in-hospital mortality, suggesting that additional therapeutic strategies are required. Left anterior descending coronary artery (LAD) ligation in rats is an animal model for acute myocardial IR research that is comparable to the clinical scenario in which rapid coronary recanalization through PCI is used for STEMI; however, PCI-induced STEMI is a technically challenging and complicated operation associated with high mortality and great variation in infarction size. We identified the ideal position for LAD ligation, created a gadget to control a snare loop, and supported a modified surgical maneuver, thereby reducing tissue damage, to establish a reliable and reproducible acute myocardial ischemia-reperfusion (IR) research protocol for rats. This is a non-survival surgery. We also propose a method for validating the quality of study results, which is a critical step for determining the accuracy of subsequent biochemical analyses.

Herein, we present a protocol focusing on the quality control of the left anterior descending coronary artery ligation by technically modifying the traditional procedure in rats for acute myocardial ischemia-reperfusion research.

Coronary heart disease is the leading cause of death globally. Complete cessation of blood flow in coronary arteries causes ST-segment elevation ...

Adjunctive Exosome Therapy: Enhancing Myocardial Recovery Post-CABG Surgery

Surgical Porcine Model of Chronic Myocardial Ischemia Treated by Exosome-laden Collagen Patch and Off-pump Coronary Artery Bypass Graft

Chronic myocardial ischemia resulting from progressive coronary artery stenosis leads to hibernating myocardium (HIB), defined as myocardium that adapts to reduced oxygen availability by reducing metabolic activity, thereby preventing irreversible cardiomyocyte injury and infarction. This is distinct from myocardial infarction, as HIB has the potential for recovery with revascularization. Patients with significant coronary artery disease (CAD) experience chronic ischemia, which puts them at risk for heart failure and sudden death. The standard surgical intervention for severe CAD is coronary artery bypass graft surgery (CABG), but it has been shown to be an imperfect therapy, yet no adjunctive therapies exist to recover myocytes adapted to chronic ischemia. To address this gap, a surgical model of HIB using porcine that is amenable to CABG and mimics the clinical scenario was used. The model involves two surgeries. The first operation involves implanting a 1.5 mm rigid constrictor on the left anterior descending (LAD) artery. As the animal grows, the constrictor gradually causes significant stenosis resulting in reduced regional systolic function. Once the stenosis reaches 80%, the myocardial flow and function are impaired, creating HIB. An off-pump CABG is then performed with the left internal mammary artery (LIMA) to revascularize the ischemic region. The animal recovers for one month to allow for optimal myocardial improvement prior to sacrifice. This allows for physiologic and tissue studies of different treatment groups. This animal model demonstrates that cardiac function remains impaired despite CABG, suggesting the need for novel adjunctive interventions. In this study, a collagen patch embedded with mesenchymal stem cell (MSC)-derived exosomes was developed, which can be surgically applied to the epicardial surface distal to LIMA anastomosis. The material conforms to the epicardium, is absorbable, and provides the scaffold for the sustained release of signaling factors. This regenerative therapy can stimulate myocardial recovery that does not respond to revascularization alone. This model translates to the clinical arena by providing means of physiological and mechanistic explorations regarding recovery in HIB.

Author Spotlight: Enhancing Coronary Artery Revascularization

This study presents a surgical porcine model of chronic myocardial ischemia due to progressive coronary artery stenosis, resulting in impaired cardiac function without infarction. Following ischemia, animals undergo off-pump coronary artery bypass graft with epicardial placement of stem cells-derived exosomes-laden collagen patch. This adjunctive therapy improves myocardial function and recovery.

Chronic myocardial ischemia resulting from progressive coronary artery stenosis leads to hibernating myocardium (HIB), defined as myocardium that adapts ...

Direct Re-implantation of Left Coronary Artery into the Aorta in Adults with Anomalous Origin of Left Coronary Artery from the Pulmonary Artery (ALCAPA)

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