Coronary Artery Anomalies in Children
Julie A. Brothers
J. William Gaynor
INTRODUCTION
This chapter focuses on managing coronary artery anomalies in patients without other congenital heart defects. Most coronary artery anomalies in number, origin, and distribution are of intellectual interest only. However, there are a few that are clinically significant and may result in myocardial ischemia, left ventricular dysfunction, and sudden death. This chapter will discuss anomalous origin of a coronary artery from the pulmonary artery, anomalous coronary artery that runs between the aorta and the pulmonary artery, and coronary artery fistula.
Normally, two-coronary arteries originate from separate ostia in the right and left aortic sinuses of Valsalva. The left main coronary artery (LMCA) arises from the left aortic sinus and usually bifurcates into the left anterior descending coronary artery (LAD) and left circumflex coronary artery. The LAD courses in the anterior interventricular groove while the left circumflex coronary artery runs in the left atrioventricular groove. The right coronary artery (RCA) arises anteriorly from the right aortic sinus and courses in the right atrioventricular groove. The RCA usually gives rise to the posterior descending artery at its terminus.
In most people, each coronary artery ostia is centrally located in the appropriate sinus of Valsalva. However, in some individuals the ostium may be located eccentrically close to a valve commissure. One or both coronary ostia may arise above the sinotubular junction, which is usually a benign finding but becomes significant if an aortotomy is necessary for aortic valve replacement or for another indication. If this anatomy is not recognized prior to the operation, the coronary artery could be transected. Another type of anomaly occurs when both coronary arteries arise from the same aortic sinus with either a single ostium or two separate ostia (Table 98.1). If the aberrant vessel courses posterior to the aorta or anterior to the pulmonary artery, this is believed to be benign but it becomes clinically significant if either the aberrant LMCA or RCA courses intramurally between the two great vessels as this has the potential for myocardial ischemia and sudden death.
ANOMALOUS ORIGIN OF A CORONARY ARTERY FROM THE PULMONARY ARTERY
Anomalous origin of a coronary artery from the pulmonary artery is a rare congenital anomaly that is almost always fatal if not diagnosed and treated. While anomalous origin of the LMCA from the pulmonary artery (ALCAPA) is the most common, other coronary arteries may also arise from the pulmonary artery. The RCA may arise from the pulmonary artery and is associated with ischemia and sudden cardiac death but is approximately 10 times less common than ALCAPA. Extremely rare are instances where the LAD, the circumflex, or both the left and right coronary arteries arise from the pulmonary artery; these variants are almost uniformly fatal.
The most important congenital coronary artery anomaly in this class is ALCAPA. It is a rare lesion with an incidence of 1 in 30,000 to 1 in 300,000 people. If left untreated, there is an extremely high mortality rate of 90% by age 1 year. It is the most common cause of myocardial infarction in childhood. ALCAPA is also known as the Bland-White-Garland syndrome after Bland and colleagues reported on both the clinical and autopsy findings in an infant with this anomaly in 1933.
Anatomy
In ALCAPA, the LMCA usually arises from the main pulmonary artery (MPA) but occasionally it will arise from the right pulmonary artery. When it arises from the MPA, it usually originates from the rightward aspect of the posterior (facing) sinus of the MPA (Figs. 98.1 and 98.2). It may also originate from the leftward aspect of the posterior (facing) and rarely from the ante rior (nonfacing) sinus of the MPA (Fig. 98.2). An anomalous RCA usually arises from the anterior portion of the pulmonary artery.
ALCAPA usually occurs in isolation but there may be other associated defects, such as patent ductus arteriosus (PDA), ventricular septal defect (VSD), coarctation of the aorta, and tetralogy of Fallot.
Pathophysiology
Symptoms usually begin during infancy after ductal closure and the subsequent fall in the pulmonary vascular resistance. During fetal life, the systemic and pulmonary vascular resistances are similar and myocardial perfusion remains intact since the pulmonary arterial pressure is systemic. After the child is born but before ductal closure, the pulmonary artery pressure remains elevated, and the anomalous coronary artery remains perfused. Because of this, ALCAPA is rarely diagnosed in the first few days of life. After ductal closure, the clinical course is largely determined by the presence or absence of collaterals from the RCA to the left coronary system. If there is inadequate collateral circulation, myocardial ischemia and ventricular dysfunction will result from inadequate myocardial perfusion because the pulmonary artery pressure is now much lower than the systemic pressure and the left ventricle is being perfused with desaturated blood at a low pressure. If the pulmonary artery pressure remains elevated due to the presence of a PDA or VSD, then the left ventricular perfusion pressure may be adequate and ischemia may not occur. If ALCAPA is unknown prior to the closure of these defects, it will become apparent shortly after with the subsequent drop in pulmonary arterial pressure, usually with fatal outcomes.
If there is adequate collateralization, then the perfusion of the left coronary system is maintained. However, as the pulmonary vascular resistance falls, a left-to-right shunt develops from the RCA to the pulmonary artery. There is progressive dilation of the RCA and left coronary artery
systems, with reversal of flow in the left coronary leading to a pulmonary-coronary steal. The left-to-right shunt is relatively small related to overall cardiac output but is significant considering coronary blood flow. Children with significant collateral circulation may survive past infancy; however, there is usually progressive left ventricular dysfunction. In a small percentage of children, the collateral vessels are enough to maintain adequate myocardial perfusion at rest and sometimes even during exertion allowing these patients to not present until adulthood.
systems, with reversal of flow in the left coronary leading to a pulmonary-coronary steal. The left-to-right shunt is relatively small related to overall cardiac output but is significant considering coronary blood flow. Children with significant collateral circulation may survive past infancy; however, there is usually progressive left ventricular dysfunction. In a small percentage of children, the collateral vessels are enough to maintain adequate myocardial perfusion at rest and sometimes even during exertion allowing these patients to not present until adulthood.
Table 98.1 Origin of Both Coronary Arteries from One Sinus | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
 Fig. 98.1. The aorta and pulmonary artery showing anomalous origin of the left main coronary artery from the posterior-facing sinus of the pulmonary artery with the anomalous artery coursing behind the pulmonary artery. |
Clinical Presentation
Clinical presentation is usually between 4 and 6 weeks of age after the pulmonary vascular resistance has fallen. However, infants may not present until closer to 2 to 3 months of age when symptoms have increased in severity. Presenting signs and symptoms are those of congestive heart failure, including sweating and discomfort with feeding, tachypnea, poor weight gain, and pallor. The discomfort with feeding likely represents myocardial ischemia. Children who do not present as infants may be diagnosed at several months of age due to a loud murmur of mitral regurgitation (MR) secondary to papillary muscle dysfunction and ventricular dilation. Rarely, older children, adolescents, and adults may remain asymptomatic yet others may come to clinical attention because of exertional chest pain, presyncope, or syncope. There have been reports of sudden death with exercise in these older patients. The symptoms associated with anomalous origin of the RCA from the pulmonary artery are less severe and presentation may be at a later age during childhood but myocardial ischemia and death can still occur.
Physical examination of the infant with ALCAPA may demonstrate signs of congestive heart failure, including tachypnea, tachycardia, and hepatomegaly. Left ventricular dysfunction due to ALCAPA can be difficult to distinguish from dilated cardiomyopathy, for which it is often confused. The left heart is usually enlarged, often with associated MR and a gallop rhythm. If the left ventricular failure has resulted in pulmonary hypertension, then there may also be evidence of right heart enlargement and an accentuated pulmonary component of the second heart sound on examination.
Infants with ALCAPA will typically have an enlarged cardiac silhouette on
chest X-ray, essentially due to the enlarged left atrium and left ventricle. It will look similar to dilated cardiomyopathy. In infants presenting with congestive heart failure, the electrocardiogram can be a useful diagnostic tool. Classically, these patients have developed lateral or anterolateral wall infarction with Q waves and ST segment elevation in leads I, aVL, and V4 to V6. While this electrocardiographic pattern can be found in other causes of myocardial infarction or cardiomyopathy, if this is seen in an infant in congestive heart failure, the diagnosis of ALCAPA needs to be strongly considered. As well, any infant presenting with dilated cardiomyopathy must be extensively evaluated to rule out ALCAPA. This diagnosis should also be considered in older children and adolescents with dilated cardiomyopathy because occasionally patients survive past infancy.
chest X-ray, essentially due to the enlarged left atrium and left ventricle. It will look similar to dilated cardiomyopathy. In infants presenting with congestive heart failure, the electrocardiogram can be a useful diagnostic tool. Classically, these patients have developed lateral or anterolateral wall infarction with Q waves and ST segment elevation in leads I, aVL, and V4 to V6. While this electrocardiographic pattern can be found in other causes of myocardial infarction or cardiomyopathy, if this is seen in an infant in congestive heart failure, the diagnosis of ALCAPA needs to be strongly considered. As well, any infant presenting with dilated cardiomyopathy must be extensively evaluated to rule out ALCAPA. This diagnosis should also be considered in older children and adolescents with dilated cardiomyopathy because occasionally patients survive past infancy.
 Fig. 98.2. (A) Anomalous origin of left main coronary artery from the rightward aspect of the posteriorfacing sinus of the pulmonary artery. (B) Anomalous origin of the left main coronary artery from the leftward aspect of the posterior-facing sinus. (C) Anomalous origin of the left main coronary artery from the nonfacing sinus of the pulmonary artery. |
Diagnostic Imaging
Imaging by echocardiography with Doppler color flow often shows a dilated left ventricle with significant MR. The MR seen with ALCAPA is due to infarction of the mitral valve posterior leaflet and ensuing poor movement of the leaflet; fibrosis and fibroelastosis of the papillary muscle may also be present. Visualization of both coronary arteries is usually possible with echocardiography. An enlarged RCA is almost always present and should increase suspicion of this diagnosis. The origins of both coronary arteries should be identified, including the abnormal origin of the LMCA to the pulmonary artery. If visualization of the anomalous vessel is unclear, color flow Doppler may be useful to demonstrate retrograde flow from the coronary artery to the pulmonary artery. If there is uncertainty about visualization of both coronary ostia, then cardiac catheterization is mandatory to rule out ALCAPA.
Cardiac catheterization with angiography traditionally was utilized in diagnosing ALCAPA but it is now performed usually only if noninvasive imaging cannot adequately establish the diagnosis. When infants present with ALCAPA, elevated filling and pulmonary arterial pressures and a low cardiac output are noted utilizing cardiac catheterization. In older asymptomatic patients, only mildly elevated pulmonary arterial pressures, normal filling pressures, and cardiac output may be seen. A small left-right shunt may be present. A single dilated RCA arising normally from the aorta will be demonstrated using an aortogram. If significant collaterals are present, aortic root angiography will demonstrate the collaterals providing late, retrograde filling of the LCA with a blush of contrast subsequently filling the MPA. A step-up in oxygen saturation may be noted in the MPA if there is a large left-right shunt from the collaterals. If doubt remains regarding the diagnosis, a main pulmonary arteriogram with distal balloon occlusion may be helpful in demonstrating the anomalous LCA.
Magnetic resonance imaging (MRI) has emerged as a useful noninvasive diagnostic tool for defining congenital coronary anomalies. There have been case reports of using this method in diagnosing ALCAPA during infancy but no case series with this anomaly have been reported. However, studies have shown that magnetic resonance angiography has a similar sensitivity and specificity when compared with coronary angiography and may be helpful in delineating the proximal course of anomalous coronary arteries. Computed tomography (CT) scan has been used extensively for coronary artery delineation in adults. While there are many advantages of CT, including rapid acquisition time and high resolution, it is not useful in infants due to the radiation exposure and need for a slower heart rate with ECG gating.
Surgical Management
Indications
Surgical repair is indicated in all patients with ALCAPA. In infants who present with congestive heart failure, surgery should occur within the first few days of diagnosis as risk of continuing myocardial ischemia and death is very high. In an infant who presents with severe heart failure, surgery will likely need to be delayed for at least 24 hours to stabilize the patient using mechanical ventilation, inotropic support, and vasodilators, when necessary. Even in the sickest infants, Del Nido and colleagues reported that a two-vessel surgical repair is possible if left ventricular assist devices (LVAD) are utilized postoperatively. Other critically ill infants may need extracorporeal membrane oxygenation (ECMO). Since these infants are often quite ill, it is important that centers performing ALCAPA surgery have options such as LVAD and ECMO available or else the child should be transferred to a hospital with these capabilities. In older asymptomatic patients, surgery can be performed on an elective basis.
As the goal of surgery is restoration of a two-coronary system, simple ligation of the anomalous coronary should not be performed. Revascularization is possible even in those infants with severe left ventricular dysfunction and mitral insufficiency because significant recovery of function usually occurs. Even if severe MR is present, left ventricular aneurysmectomy and mitral valve repair or replacement are rarely indicated at the time of the initial procedure because the severity of MR almost always improves after revascularization.
Surgical Techniques
History of Surgical Techniques
The first successful operation for the correction of ALCAPA was surgical ligation of the anomalous artery at the pulmonary artery. Ligating the anomalous vessel prevents the left-to-right shunt, thus allowing the left ventricle to be perfused through collaterals from the RCA. However, due to the increased risk of late death after ligation, those children who have had a simple ligation of the anomalous coronary, establishment of a dual coronary artery system
should be considered. Because of the high rate of early mortality and increased risk of late sudden death with this procedure, a variety of techniques were developed to create a dual coronary artery system, including coronary artery bypass grafting (CABG), aortopulmonary window, and direct reimplantation.
should be considered. Because of the high rate of early mortality and increased risk of late sudden death with this procedure, a variety of techniques were developed to create a dual coronary artery system, including coronary artery bypass grafting (CABG), aortopulmonary window, and direct reimplantation.
CABG was accomplished using the left subclavian artery, the internal mammary artery (IMA), and saphenous vein. The first successful left subclavian artery-to-left coronary bypass was reported by Meyer and colleagues in 1968. Unfortunately, the results of bypass grafting, notably those with saphenous vein grafts, have been disappointing. Takeuchi and colleagues subsequently described the creation of an aortopulmonary window and intrapulmonary artery baffle using a pulmonary artery flap to direct blood flow from the aorta to the anomalous coronary artery. Finally, the procedure of choice in many institutions has become direct reimplantation of the anomalous coronary to the aorta as experience with the arterial switch operation for transposition of the great vessels has increased.
Coronary Artery Bypass Grafting
Left Subclavian-to-Left Coronary Artery Anastomosis. In the current era, CABG is rarely utilized in patients with ALCAPA. It may be used, however, to create a dual coronary artery system after previous ligation or due to stenosis or occlusion after a previous surgical repair. Left subclavian-to-left coronary artery anastomosis may be performed via a median sternotomy using cardiopulmonary bypass or via a left posterolateral thoracotomy without cardiopulmonary bypass. Using cardiopulmonary bypass may be necessary for the stabilization of critically ill infants but subclavian artery mobilization may be difficult through a median sternotomy. When a left thoracotomy is used, heparin is administered followed by mobilization of the subclavian artery. The subclavian artery is then divided distally. After the pericardium is opened, the anomalous coronary is mobilized. A partial occlusion clamp is placed and the anomalous coronary ostium is excised using a small button of pulmonary artery. An end-to-end anastomosis is created between the subclavian and coronary arteries with 7-0 Prolene. Repair of the pulmonary artery may be accomplished either primarily or with a patch of autologous pericardium. A different surgical approach is ligation of the anomalous coronary at the take-off from the pulmonary artery and creation of an end-to-side anastomosis between the subclavian and coronary arteries. The main reason the left subclavian-to-left coronary artery anastomosis is not used frequently is due to the risk of anastomotic stenosis or occlusion.
Left Internal Mammary Artery Grafting.
The IMA is the conduit of choice in CABG. Due to the risk of occlusion and poor long-term results, the saphenous vein should not be utilized unless it is the only conduit available. The IMA can be successfully used for bypass grafting even in neonates and infants with some evidence for growth of the IMA after bypass grafting in children.
Direct Reimplantation
In most patients with ALCAPA, direct reimplantation of the anomalous coronary artery onto the aorta can be performed (Fig. 98.3) and is the procedure of choice. When the anomalous coronary ostium is located in the posterior-facing sinus, the procedure is fairly straightforward. Direct implantation is possible even if the ostium is located in the nonfacing sinus by excising a large button of pulmonary artery to extend the coronary artery. However, if the anomalous left coronary originates far leftward in the posterior-facing sinus or on the anterior nonfacing sinus, direct reimplantation may not be possible.
 Fig. 98.3. After institution of cardiopulmonary bypass and induction of cardioplegia, the pulmonary artery is transected above the sinotubular junction and the anomalous coronary ostium excised with a generous button of pulmonary artery wall. |
After induction of anesthesia and placement of monitoring lines, a median sternotomy is performed. The thymus is resected, the pericardium is opened and suspended in stay sutures. There is a risk of ventricular fibrillation due to myocardial ischemia and left ventricular dysfunction, so contact with the myocardium should be kept at a minimum until the patient is placed on cardiopulmonary bypass. This operation may be performed using either continuous low-flow bypass with moderate hypothermia (25°C to 28°C) or deep hypothermic circulatory arrest (18°C) in very small infants. Prior to cannulization, an aortic purse-string suture is placed distally near the innominate artery and another is placed in the right atrial appendage for a single venous cannula. Heparin is administered, the aortic and right atrial cannulas are inserted, and cardiopulmonary bypass is established. The left ventricle should be decompressed by the placement of a left ventricular vent via the right superior pulmonary vein. The pulmonary artery and epicardial course of the left coronary artery are visualized.
The aorta and both pulmonary arteries are fully mobilized. The ductus (or ligamentum) arteriosus is ligated to improve the mobility of the pulmonary artery. Tourniquets are placed around both the right and left branch pulmonary arteries
to occlude the branch pulmonary arteries and prevent run-off of cardioplegic solution into the lungs. Another way to prevent run-off is compression of the origin of the coronary artery from the pulmonary artery during administration of cardioplegic solution. A cannula is inserted in the ascending aorta for administration of cardioplegia solution. The aorta is then cross-clamped and cold cardioplegia is administered via the aortic root. If circulatory arrest is utilized, the head vessels are then occluded with tourniquets, the circulation is arrested, venous blood is drained into the reservoir, and the cannulae are removed. After adequate arrest, the pulmonary artery is transversely opened just above the sinotubular junction (Fig. 98.3). The anomalous coronary orifice is identified. The pulmonary artery is divided and the coronary ostium is excised from the pulmonary artery using a generous button of arterial wall, similar to the procedure used in the arterial switch operation. The segment of the pulmonary wall that is excised extends the proximal end of the coronary artery, which allows the aortic anastomosis to be accomplished without tension. The aortic commissure may need to be taken down to excise the coronary button if the coronary ostium is located near a commissure. If the coronary artery arises anteriorly from the pulmonary artery or from a branch pulmonary artery, the coronary artery can be extended using a tube constructed from pulmonary artery wall to allow reimplantation (Fig. 98.4). Using cautery, the proximal portion of the coronary artery is mobilized cautiously to avoid any small branches. Similar to the arterial switch operation, the aorta is then opened transversely just above the sinotubular junction and the incision is carried posteriorly above the left posterior sinus (Fig. 98.5). The sinus is then incised vertically to accept the coronary button. The coronary button is carefully aligned with the aortic incision to avoid twisting or kinking. Using a continuous suture of 7-0 polypropylene (Prolene), the anastomosis is started at the most inferior aspect of the coronary button, which is attached to the most inferior aspect of the incision in the sinus. The suture line is carried to the top of the incision anteriorly and posteriorly. The aorta is closed using a continuous suture of 7-0 Prolene, which is tied to the coronary button suture as the anastomosis is completed (Fig. 98.5). After the aorta has been closed, cardioplegia solution is administered and the anastomotic site is inspected for adequate filling of the coronary and hemostasis.
to occlude the branch pulmonary arteries and prevent run-off of cardioplegic solution into the lungs. Another way to prevent run-off is compression of the origin of the coronary artery from the pulmonary artery during administration of cardioplegic solution. A cannula is inserted in the ascending aorta for administration of cardioplegia solution. The aorta is then cross-clamped and cold cardioplegia is administered via the aortic root. If circulatory arrest is utilized, the head vessels are then occluded with tourniquets, the circulation is arrested, venous blood is drained into the reservoir, and the cannulae are removed. After adequate arrest, the pulmonary artery is transversely opened just above the sinotubular junction (Fig. 98.3). The anomalous coronary orifice is identified. The pulmonary artery is divided and the coronary ostium is excised from the pulmonary artery using a generous button of arterial wall, similar to the procedure used in the arterial switch operation. The segment of the pulmonary wall that is excised extends the proximal end of the coronary artery, which allows the aortic anastomosis to be accomplished without tension. The aortic commissure may need to be taken down to excise the coronary button if the coronary ostium is located near a commissure. If the coronary artery arises anteriorly from the pulmonary artery or from a branch pulmonary artery, the coronary artery can be extended using a tube constructed from pulmonary artery wall to allow reimplantation (Fig. 98.4). Using cautery, the proximal portion of the coronary artery is mobilized cautiously to avoid any small branches. Similar to the arterial switch operation, the aorta is then opened transversely just above the sinotubular junction and the incision is carried posteriorly above the left posterior sinus (Fig. 98.5). The sinus is then incised vertically to accept the coronary button. The coronary button is carefully aligned with the aortic incision to avoid twisting or kinking. Using a continuous suture of 7-0 polypropylene (Prolene), the anastomosis is started at the most inferior aspect of the coronary button, which is attached to the most inferior aspect of the incision in the sinus. The suture line is carried to the top of the incision anteriorly and posteriorly. The aorta is closed using a continuous suture of 7-0 Prolene, which is tied to the coronary button suture as the anastomosis is completed (Fig. 98.5). After the aorta has been closed, cardioplegia solution is administered and the anastomotic site is inspected for adequate filling of the coronary and hemostasis.
In most cases, the pulmonary artery can be repaired primarily with a continuous suture of 7-0 Prolene (Fig. 98.6). The ductus (or ligamentum) should be divided to improve mobility of the pulmonary artery confluence and to allow reconstruction without tension. If there is tension or narrowing, the pulmonary artery should be repaired with a patch of autologous pericardium (Fig. 98.6). If a commissure was taken down during excision of the coronary button, the pulmonary artery should be reconstructed with pericardium and the commissure resuspended.
 Fig. 98.4. Occasionally, when the coronary artery arises from the leftward or anterior aspect of the pulmonary artery, direct reimplantation may not be possible. In these situations, a tube can be constructed from a segment of pulmonary artery to lengthen the coronary and to allow reimplantation on the aorta. |
 Fig. 98.5. After the anomalous coronary artery is mobilized, the aorta is opened transversely above the sinotubular junction and a vertical incision is made in the left posterior sinus to accept the reimplanted coronary. |
The patient is rewarmed and the aortic cross-clamp is removed. To minimize
ischemia time, the cross-clamp may be removed prior to the pulmonary artery reconstruction. The left ventricle is inspected for adequate perfusion and function and the suture lines are inspected for hemostasis. Right and left atrial lines are placed to adequately monitor pressure and for drug administration. Atrial and ventricular pacing wires are also placed. After complete warming, the patient is separated from cardiopulmonary bypass. Careful attention to the electrocardiogram during reperfusion and after separation from bypass is necessary to evaluate for ischemia. Inotropic support may be temporarily needed due to preoperative left ventricular dysfunction.
ischemia time, the cross-clamp may be removed prior to the pulmonary artery reconstruction. The left ventricle is inspected for adequate perfusion and function and the suture lines are inspected for hemostasis. Right and left atrial lines are placed to adequately monitor pressure and for drug administration. Atrial and ventricular pacing wires are also placed. After complete warming, the patient is separated from cardiopulmonary bypass. Careful attention to the electrocardiogram during reperfusion and after separation from bypass is necessary to evaluate for ischemia. Inotropic support may be temporarily needed due to preoperative left ventricular dysfunction.
 Fig. 98.6. After the coronary is reimplanted, the aorta is closed primarily. The pulmonary artery may frequently be closed primarily. Ligation and division of the ligamentum arteriosus improves the mobility of the pulmonary artery. Occasionally, patch repair of the defect in the pulmonary artery with autologous pericardium may be necessary (inset). |
Modified Takeuchi Operation
The Takeuchi operation, or intrapulmonary artery tunnel, is an alternative surgical repair strategy for ALCAPA. Takeuchi and colleagues originally described the creation of an aortopulmonary window using a portion of anterior pulmonary artery wall to form a baffle directing blood from the aorta to the anomalous coronary artery ostium. In the modified repair, the baffle is constructed using a polytetrafluoroethylene (PTFE, Gore-Tex) patch. If the ostium is located near a commissure or arises from a branch pulmonary artery, then creating a baffle may not be possible.
 Fig. 98.7. After institution of cardiopulmonary bypass and induction of cardioplegia, a longitudinal incision is made in the main pulmonary artery and the ostium of the abnormal coronary is identified. |
The procedure may be performed with either continuous low-flow cardiopulmonary bypass (25°C to 28°C) or deep hypothermic circulatory arrest (18°C). Cannulation is performed as for direct reimplantation. After induction of cardioplegia, a longitudinal incision is made in the anterior portion of the pulmonary artery (Fig. 98.7) and the ostium of the anomalous coronary is identified. Using a punch, a 5 mm diameter opening is made on the leftward aspect of the aorta above the sinotubular junction (Fig. 98.8). If there is any question regarding the placement of the aortic opening, then an anterior aortotomy should be performed, and the incision directly visualized to avoid damage to the aortic valve. Creating the aortopulmonary window above the sinotubular junction allows a downward angle of the baffle into the sinus if the ostium is located deep within a sinus. After a similar incision is made in the pulmonary artery directly opposite the opening in the aorta, these are anastomosed using a continuous suture of 7-0 Prolene, thereby creating an aortopulmonary window (Fig. 98.8).
A4 mm PTFE tube graft is split longitudinally and customized to an appropriate length (Fig. 98.9). This graft acts as an intrapulmonary artery tunnel, baffling blood from the aortopulmonary window to the anomalous coronary ostium. The suture line starts at the anomalous coronary and is continued inferiorly along the pulmonary artery wall to the aortopulmonary window. The suture line is completed by returning to the coronary artery and finishing the superior aspect of the baffle. After the baffle is created, the pulmonary artery can be repaired using a prosthetic patch or autologous pericardium to avoid supravalvar right ventricular outflow tract obstruction (Fig. 98.10).
A4 mm PTFE tube graft is split longitudinally and customized to an appropriate length (Fig. 98.9). This graft acts as an intrapulmonary artery tunnel, baffling blood from the aortopulmonary window to the anomalous coronary ostium. The suture line starts at the anomalous coronary and is continued inferiorly along the pulmonary artery wall to the aortopulmonary window. The suture line is completed by returning to the coronary artery and finishing the superior aspect of the baffle. After the baffle is created, the pulmonary artery can be repaired using a prosthetic patch or autologous pericardium to avoid supravalvar right ventricular outflow tract obstruction (Fig. 98.10).
 Fig. 98.8. Using a punch, a 5 mm opening is made in the aorta on the leftward aspect above the sinotubular junction. A similar opening is made in the pulmonary artery at the same level, and these are anastomosed to create an aortopulmonary window. |
 Fig. 98.9. A segment of 4 mm polytetrafluoroethylene (Gore-Tex) graft is opened longitudinally and used to fashion a baffle that directs blood flow from the aortopulmonary window to the anomalous coronary ostium. |
The main complications of the modified Takeuchi operation include baffle leak, baffle occlusion, and supravalvar right ventricular outflow tract obstruction.
Postoperative Management
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
