You are in: eMedicine Specialties > Pediatrics: Cardiac Disease and Critical Care Medicine > Cardiothoracic Surgery Anomalous Left Coronary Artery From the Pulmonary Artery: Surgical PerspectiveArticle Last Updated: Nov 1, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 12
  Author: Mary C Mancini, MD, PhD, Director of Cardiothoracic Transplantation, Professor, Department of Surgery, Louisiana State University Health Sciences Center Mary C Mancini is a member of the following medical societies: American Heart Association, American Medical Association, American Thoracic Society, Association for Academic Surgery, Association for Surgical Education, International College of Surgeons, International Society for Heart and Lung Transplantation, New York Academy of Sciences, Phi Beta Kappa, and Southern Thoracic Surgical Association Coauthor(s): Kerry Rosen, MD, Assistant Professor, Department of Pediatrics, Pennsylvania State University; Director of Echocardiography, Department of Pediatrics, Milton S Hershey Medical Center; Christopher Mart, MD, Associate Professor, Pediatric Echocardiography, Department of Pediatrics, Division of Pediatric Cardiology, University of Utah, Primary Children's Medical Center; John Myers, MD, Director, Pediatric and Congenital Cardiovascular Surgery, Departments of Surgery and Pediatrics, Professor, Penn State Children's Hospital, Milton S Hershey Medical Center Editors: Daniel S Schwartz, MD, FACS, Clinical Assistant Professor of Cardiothoracic Surgery, New York University School of Medicine; Consulting Staff, Department of Surgery, Division of Thoracic Surgery, North Shore University Hospital/Long Island Jewish Medical Center; Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc; Mary C Mancini, MD, PhD, Director of Cardiothoracic Transplantation, Professor, Department of Surgery, Louisiana State University Health Sciences Center; Daniel Rauch, MD, FAAP, Director, Pediatric Hospitalist Program, Associate Professor, Department of Pediatrics, New York University School of Medicine; Steven Neish, MD, SM, Director of Pediatric Cardiology Fellowship Program, Department of Pediatrics, Baylor College of Medicine Author and Editor Disclosure Synonyms and related keywords: anomalous left coronary artery from the pulmonary artery, ALCAPA, pulmonary anastomosis, cardiac surgery, pulmonary artery dysfunction, abnormal pulmonary artery, direct transfer of an anomalous coronary artery, direct transfer of the left coronary artery, ALCAPA anastomosis, intrapulmonary aortocoronary tunnel, Takeuchi repair, bypass grafting, internal mammary grafting, saphenous venous grafting, direct transfer of an ALCAPA, Bland-Garland-White syndrome INTRODUCTIONSection 2 of 12
  History of the ProcedureEarly surgical attempts at repair of an anomalous left coronary artery from the pulmonary artery (ALCAPA) were palliative. In 1953, Potts proposed an aortopulmonary anastomosis to increase oxygen saturation in the main pulmonary artery. Also in 1953, Mustard described a left carotid artery–to–anomalous left coronary artery procedure.1 In 1959, Sabiston et al proposed simple ligation of the proximal origin of the anomalous left coronary artery.2 In 1966, Cooley et al used saphenous vein grafting from the aorta to the anomalous left coronary artery.3 In 1968, Meyer et al described a left subclavian artery–to–anomalous left coronary artery repair.4 An internal mammary artery–to–ALCAPA procedure has also been performed. Pulmonary artery banding has been attempted to increase perfusion pressure in the ALCAPA. In addition, procedures to increase collateral circulation, such as poudrage and de-epicardialization, have been tried. Each of the above procedures has fallen out of favor. Today, establishing a system with 2 coronary arteries is the goal in definitive surgical repair. Direct anastomosis of the ALCAPA directly to the aorta was described in the 1970s and currently remains the procedure of choice. The experience gained in coronary artery transfer during the arterial switch operation has facilitated techniques for coronary transfer to repair the ALCAPA. In most patients, the anomalous left coronary artery is situated in a position that allows for direct transfer of the anomalous coronary artery. For patients in whom direct transfer of the coronary artery is not feasible, performing the novel repair of creating an intrapulmonary aortocoronary tunnel may be appropriate, as described by Takeuchi in 1979. Occasionally, cardiac transplantation has been required in patients with ALCAPA with severe cardiac dysfunction. ProblemThe origin of the left main coronary artery is anomalous. The left main coronary artery abnormally originates from the pulmonary artery. Although rare, this is a very significant lesion that requires prompt recognition and diagnosis. With early diagnosis, prognosis is excellent after surgical repair. FrequencyALCAPA is rare in the United States, affecting 1 in 300,000 live births. ALCAPA represents approximately 0.25-0.5% of congenital heart defects. No data are available to suggest variance in the frequency of ALCAPA in different countries or between social, economic, or ethnic groups. EtiologyThe coronary arterial circulation is established by 45 days' gestation in the fetus. ALCAPA is caused either by abnormal division of the conotruncus or by abnormal involution of endothelial buds that are present on all 6 sinuses of Valsalva of the great vessels. Usually, all but 2 of the endothelial buds involute, leaving 2 buds in the aortic sinuses to eventually become the coronary arteries. With ALCAPA, an endothelial bud sometimes persists on a pulmonary sinus and attaches to the developing left main coronary artery. The left coronary artery can also connect to other locations in the pulmonary artery and has even been reported to connect to one of the branch pulmonary arteries. ALCAPA usually occurs as an isolated defect; however, it has been associated with congenital defects, including ventricular septal defect, patent ductus arteriosus, and coarctation of the aorta. One case report has documented ALCAPA in a patient with hypoplastic left heart syndrome. PathophysiologyThe pathophysiology of ALCAPA varies and depends on the patient's age, the pulmonary vascular resistance/pressure, the presence of collateral vessels between the right and left coronary artery systems, and the degree of myocardial ischemia. Four physiologic stages have been described, as follows:
Myocardial ischemia occurs in an anterolateral distribution, causing global left ventricular dilation and dysfunction. Mitral valve regurgitation is common secondary to papillary muscle infarction, mitral annular dilation, or both. Left atrial dilation and pulmonary venous congestion ensue, adding congestive symptoms to those of angina pectoris. ClinicalHistorically, the defect was termed Bland-Garland-White syndrome. In 1933, Bland et al first eloquently described the clinical presenting signs in infants with ALCAPA. The following description is of a 10-week-old infant: …while nursing from the bottle, the onset of an unusual group of symptoms occurred, which consisted of paroxysmal attacks of acute discomfort precipitated by the exertion of nursing. The infant appeared at first to be in obvious distress, as indicated by short expiratory grunts, followed immediately by marked pallor and cold sweat with a general appearance of severe shock. Occasionally, with unusually severe attacks, there appeared to be a transient loss of consciousness…5 Infants present with respiratory distress, feeding intolerance, or failure to thrive. In the rare case involving an older child or adult, the patient may have exertional chest pain, dyspnea, or syncope. Unfortunately, sudden death occurs in some patients following exertion. Upon physical examination, infants have an enlarged heart and displaced apical impulse. A gallop rhythm or the holosystolic murmur of mitral regurgitation may be present. Signs of congestive heart failure may be apparent. The clinical signs of ALCAPA are nonspecific. Myocarditis and cardiomyopathy are other considerations in infants presenting with left ventricular dilation and heart failure. Careful evaluation for the presence of ALCAPA is necessary in any infant presenting with left ventricular dilation and heart failure. INDICATIONSSection 3 of 12
Demonstration of the lesion and diagnosis of anomalous left coronary artery from the pulmonary artery (ALCAPA) are an indication for surgical intervention. Prompt preparations should be made for surgical repair. Medical therapy provides a bridge to surgery and should be used to optimize the hemodynamics in the patient during the preoperative period. RELEVANT ANATOMYSection 4 of 12
In most patients, the anomalous left coronary artery originates from the posterior or leftward sinus of the pulmonary artery. Less commonly, the anomalous coronary artery arises from the right pulmonary artery. The branching of the anomalous left coronary artery is usually normal with normal left anterior descending and circumflex coronary arteries. The origin of the right coronary artery is normal; however, this vessel is usually enlarged and tortuous. CONTRAINDICATIONSSection 5 of 12
Very few contraindications for surgical repair of left coronary artery from the pulmonary artery (ALCAPA) have been identified. Even in patients with severe disease and poor left ventricular function, revascularization after repair of ALCAPA usually results in improved left ventricular function. Contraindications for surgical repair include multisystemic end-organ failure and a poor prognosis for survival with or without surgical intervention for the ALCAPA. WORKUPSection 6 of 12
Lab Studies
Imaging Studies
Other TestsElectrocardiograms can reveal an infarct pattern, typically in an anteroseptal distribution. Wide and/or deep Q waves are typically present in leads I and aVL. Loss of normal R-wave progression in the precordial leads and T-wave inversion in leads I, aVL, and the left precordial leads may be observed. The electrocardiogram changes noted above are nonspecific for ALCAPA and may be encountered in other forms of cardiomyopathy. Diagnostic Procedures
TREATMENTSection 7 of 12
Medical therapyMedical therapy should be used only to stabilize the patient for surgery. Intubation and mechanical ventilation often are needed in infants who present with shock and cardiac failure. This allows for adequate sedation and analgesia. The goal of analgesia and sedation are to minimize oxygen demands of the failing myocardium. Oxygen therapy is used to treat or prevent hypoxia. Inotropic support is often necessary. Agents such as dobutamine or milrinone are beneficial to augment cardiac function; however, milrinone should be used cautiously because it may lower afterload/blood pressure to a degree that may impair coronary perfusion. Diuretics (eg, furosemide) are useful to decrease pulmonary venous congestion. Transfusion of packed red blood cells may be useful to increase the oxygen-carrying capacity in patients who have severe anemia. Surgical therapyDirect transfer of the left coronary artery Temporary cardiopulmonary bypass and cold blood cardioplegia are used. The pulmonary artery is transected, and the anomalous coronary artery is removed as a button of tissue around the ostium of the anomalous coronary artery. This technique is similar to the technique used in the arterial switch operation. The proximal coronary is mobilized, and the button is turned posteriorly for direct anastomosis into the aortic root. A slightly smaller button of aortic root is removed, and the coronary button is transposed and sewn into place on the aortic root. The pulmonary artery is then repaired with autologous pericardium. Takeuchi repair This technique is rarely needed today because most surgeons perform direct transfer of the anomalous left coronary artery from the pulmonary artery (ALCAPA) even when the anomalous vessel is transferred over some distance. In the Takeuchi repair, an aortopulmonary window is created. The pulmonary artery is opened, creating an anterior transverse flap of native pulmonary artery tissue, which creates a baffle to carry the aortic oxygenated blood to the anomalous coronary artery. The pulmonary artery is then repaired with autologous pericardium. Complications of the Takeuchi repair include obstruction of the baffle created between the anomalous coronary artery and supravalvar pulmonary stenosis. Bypass grafting The proximal anomalous coronary can be ligated, and bypass grafting may be used to reestablish coronary perfusion. In the past, carotid artery, subclavian artery, and saphenous vein grafts were used. Currently, internal mammary grafting or saphenous venous grafting can be used when direct transfer or the Takeuchi repair is not feasible. Variations of direct transfer of the ALCAPA Several reports have documented variations of the direct transfer of the ALCAPA, as follows:
The advantage is that none of these techniques use prosthetic material to repair the ALCAPA. Preoperative detailsSee Medical Therapy. Intraoperative detailsUpon initial exposure, the dilated dysfunctional left ventricle may be susceptible to fibrillation during manipulation of the heart. During cardioplegia, both the ascending aorta and the main pulmonary artery are cannulated and cross-clamped. This provides antegrade cardioplegia in the right coronary artery and the anomalous left coronary artery. If cardioplegia is instilled in the ascending aorta only, runoff and steal of cardioplegia into the main pulmonary artery via the anomalous left coronary artery may occur. With the advent of the technique of retrograde cardioplegia, cannulation of the pulmonary artery may be eliminated in some cases. When choosing the incision site on the aorta for the aortocoronary anastomosis, transverse aortotomy is used to visualize the aortic sinus. This insures optimal location and placement of the coronary button for the aortocoronary anastomosis. Some centers advocate performing a mitral annuloplasty to treat severe mitral regurgitation. This technique remains controversial because the mitral regurgitation is usually caused by annular dilation or papillary muscle dysfunction, both of which may improve after revascularization of the left ventricular myocardium and improvement of left ventricular function. Intraoperative transesophageal echocardiography may be used to help identify and document abnormal flow in the ALCAPA and normal flow in the repaired/transposed coronary artery. Transesophageal echocardiography is also useful for postoperative monitoring of ventricular function and mitral valve regurgitation. Postoperative detailsStandard postoperative care is performed in the cardiac or pediatric intensive care unit. Blood products may be needed to control or decrease postoperative bleeding. Mechanical ventilation and inotropic support are typically required in the initial postoperative period. Afterload reduction therapy (eg, nitroprusside) is often used to control postoperative hypertension. Milrinone and epinephrine are used liberally in the immediate postoperative period. In patients in whom separation from cardiopulmonary bypass is difficult, further support with extracorporal membrane oxygenation (ECMO) may be needed. Intra-aortic balloon pump therapy may be used in older children and adults. Serial echocardiography is used to assess for improvement in the left ventricular function and mitral regurgitation. Follow-upStandard follow-up care is required after surgical repair of ALCAPA. Local care of the sternotomy incision is advised, and infants and small children should not be lifted by their arms for 6-8 weeks. Outpatient therapy with diuretics (eg, furosemide) and/or afterload reduction (eg, captopril, enalapril) is often used. Long-term follow-up care includes the use of electrocardiography and echocardiography. In older children and adults, exercise stress testing, including stress echocardiography and nuclear medicine perfusion scans, are useful to assess the patient's functional capacity postoperatively. COMPLICATIONSSection 8 of 12
Surgical complications include bleeding, infection, cardiac arrest/failure, stroke, and the need for further surgery. Most congenital heart surgery programs quote surgical mortality rates at less than 5-10%. OUTCOME AND PROGNOSISSection 9 of 12
Even in patients with severe left ventricular dilation, global left ventricular dysfunction, and mitral regurgitation, outcome and prognosis is frequently excellent after surgical reimplantation of anomalous left coronary artery from the pulmonary artery (ALCAPA). Prompt diagnosis, medical stabilization, a coordinated team approach in the operating room and postoperative intensive care unit can facilitate excellent outcomes for this relatively rare congenital defect. FUTURE AND CONTROVERSIESSection 10 of 12
Direct transfer of the anomalous left coronary artery from the pulmonary artery (ALCAPA) is the surgical procedure of choice. As specialists at most congenital heart surgery centers have gained more experience with coronary artery transfer with the arterial switch operation, surgical repair of ALCAPA has benefited from refinement of these surgical techniques. With appropriate diagnosis, presurgical stabilization, and team-oriented postoperative care, patients with ALCAPA are expected to have an excellent outcome. Further refinement of long-term follow-up care with specialized stress and functional testing (eg, nuclear medicine perfusion, stress echocardiography) is anticipated. MULTIMEDIASection 11 of 12
REFERENCESSection 12 of 12
Anomalous Left Coronary Artery From the Pulmonary Artery: Surgical Perspective excerpt Article Last Updated: Nov 1, 2007 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
