Surgical Approach to Anomalous Left Coronary Artery From the Pulmonary Artery Treatment & Management

Updated: May 22, 2017
  • Author: Mary C Mancini, MD, PhD, MMM; Chief Editor: Suvro S Sett, MD, FRCSC, FACS  more...
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Treatment

Medical Therapy

Medical 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.

Pharmacotherapy

Inotropic support is often necessary in patients with anomalous left coronary artery connected to the pulmonary artery (ALCAPA). Inotropic agents such as dobutamine or milrinone help to augment cardiac function. Use caution with administering milrinone, because it may lower afterload/blood pressure to such a degree that coronary perfusion may be impaired.

Diuretics (eg, furosemide) are useful to decrease pulmonary venous congestion. Drugs that reduce the workload of the heart include beta-blockers, which aid in neurohormonal modification, left ventricular ejection fraction (LVEF) improvement, arrhythmia prevention, and ventricular rate control, and angiotensin-converting enzyme (ACE) inhibitors, which are also useful for neurohormonal modification, vasodilatation, and LVEF improvement;

Transfusion of packed red blood cells may be useful to increase the oxygen-carrying capacity in patients who have severe anemia.

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Indications and Contraindications for Surgical Repair

Indications

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.

Contraindications

Very few contraindications for surgical repair of 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.

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Surgical Therapy

Direct transfer of the left coronary artery

Temporary cardiopulmonary bypass and cold blood cardioplegia are used for direct transfer of the left coronary artery. 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 one 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.

A retrospective review of long-term data (1980-2012; mean follow-up of 8.16 ± 6.7 years) of 30 patients with ALCAPA who underwent surgical repair with coronary transfer (n = 19), Takeuchi repair (n = 9), or closure (n = 2), demonstrated good survival rates (no deaths) and long-term ventricular function for both coronary transfer and Takeuchi repair. [14]  The 10-year rate of freedom from reintervention was 94.1% and 71.1%, respectively, for coronary transfer and Takeuchi repair. However, at 8-year follow-up, infants who underwent Takeuchi repair were significantly more likely to have at least moderate pulmonary regurgitation compared to those who underwent coronary transfer (79.9% vs 0%, P <0.001).

Takeuchi procedure/repair

Currently, the Takeuchi technique is rarely needed 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 procedure/repair, an aortopulmonary window is constructed. The pulmonary artery is opened, creating an anterior transverse flap of native pulmonary artery tissue, which forms a baffle (conduit) to carry the aortic oxygenated blood to the anomalous coronary artery. The pulmonary artery is then repaired with autologous pericardium.

Complications of the Takeuchi procedure/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 procedure/repair is not feasible.

Variations of direct transfer of the ALCAPA

Several reports have documented variations of the direct transfer of the ALCAPA, including the following:

  • The transected main pulmonary artery is used as a conduit tube in a variation of coronary angioplasty. A conduit tube of native pulmonary artery is anastomosed side-to-side to the aorta.

  • Enlarged autogenous aortic and pulmonary arterial flaps are used to create an extended left main stem coronary artery during anastomosis of the ALCAPA to the aorta.

  • Elongated flaps of the aorta and pulmonary artery are sewn side-to-side to create a tunnel from the ALCAPA to the aorta.

  • In the rare variant of ALCAPA with aortic fusion, unroofing of the intramural portion has been successful. If there is no intramural component, then direct transfer may be required, with care taken to avoid kinking of the artery. [15, 16]

  • The Lecompte maneuver has been used to reduce tension on the anastomosis between the left coronary artery and the aorta, and to prevent compression of the reimplanted left coronary artery by the posterior wall of the pulmonary artery when the left coronary artery arises from the nonfacing sinus. [17, 18]

The advantage of these techniques is that none use prosthetic material to repair the ALCAPA. [17, 18] [19]

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Intraoperative Details

Upon 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 dilatation 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 anomalous left coronary artery from the pulmonary artery (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.

Intraoperative images are shown below.

Intraoperative photograph. (1) A cardioplegia cath Intraoperative photograph. (1) A cardioplegia catheter in the ascending aorta. (2) A cross-clamp on the ascending aorta. (3) A cross-clamp on the main pulmonary artery. (4) An arterial bypass cannula in the main pulmonary artery. (5) A cardioplegia catheter in the main pulmonary artery. (6) The dilated conal branch of the right coronary artery. (7) A venous bypass cannula in the right atrial appendage. (8) A left heart vent.
Intraoperative photograph. (1) A transverse anteri Intraoperative photograph. (1) A transverse anterior incision in the main pulmonary artery trunk. (2) A probe is in the orifice of the anomalous left coronary artery.
Intraoperative photograph. (1) The divided distal Intraoperative photograph. (1) The divided distal main pulmonary artery. (2) The left coronary artery button. (3) The divided proximal main pulmonary artery.
Intraoperative photograph. (1) The left coronary a Intraoperative photograph. (1) The left coronary artery button. (2) The divided proximal main pulmonary artery. (3) A bypass sucker in the transverse aortotomy (to visualize the aortic sinuses). (4) An incision in the aortic sinus for the site of the aortocoronary anastomosis.
Intraoperative photograph. (1) Completing the anas Intraoperative photograph. (1) Completing the anastomosis of the left coronary artery to the aortic sinus. (2) The divided proximal main pulmonary artery.
Intraoperative photograph. (1) The completed anast Intraoperative photograph. (1) The completed anastomosis of the left coronary artery to the aortic sinus. (2) The divided proximal main pulmonary artery. (3) The ascending aorta, transverse aortotomy.
Intraoperative photograph. (1) Suture closure of t Intraoperative photograph. (1) Suture closure of the aortotomy.
Intraoperative photograph. (1) The distal divided Intraoperative photograph. (1) The distal divided main pulmonary artery. (2) Beginning the reanastomosis (posterior wall) of the main pulmonary artery. (3) The proximal main pulmonary artery.
Intraoperative photograph. (1) The completed repai Intraoperative photograph. (1) The completed repair of the main pulmonary artery reanastomosis.
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Postoperative Details

Standard postoperative care is performed in the cardiac or pediatric intensive care unit (ICU). 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.

A retrospective study by Weigand et al indicated that immediate postoperative morbidity in the repair of anomalous left coronary artery from the pulmonary artery (ALCAPA) is associated with patient size, the left ventricular end diastolic dimension (LVEDD), and the preoperative left ventricular shortening fraction. The investigators, who conducted the study on 44 patients, also found that the LVEDD Z-score independently predicted the length of time needed for left ventricular function to normalize and that, in infants, this score independently predicted how long the patient would require postoperative intravenous inotropic support. [20]

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Follow-up

Standard follow-up care is required after surgical repair of anomalous left coronary artery from the pulmonary artery (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, [21] including stress echocardiography and nuclear medicine perfusion scans, are useful to assess the patient's functional capacity postoperatively.

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Outcome and Prognosis

Even in patients with severe left ventricular dilatation, global left ventricular dysfunction, and mitral regurgitation, the outcome and prognosis is frequently excellent after surgical reimplantation of anomalous left coronary artery from the pulmonary artery (ALCAPA). [22] Prompt diagnosis, medical stabilization, and a coordinated team approach in the operating room and postoperative intensive care unit can facilitate excellent outcomes for this relatively rare congenital defect.

A retrospective study (1994-2015) of 96 Chinese patients with ALCAPA who underwent surgical repair and had a mean follow-up of 10.45 ± 8.96 years found early and late improvement of left ventricular function in most patients. [23] Three patients underwent ligation, six patients underwent ligation and coronary artery bypass grafting, 14 underwent transpulmonary baffling, and 73 patients underwent direct implantation of the anomalous coronary artery into the aorta. Death occurred in three patients (1 early, 2 late). [23]

A retrospective study of data from 33 Japanese infant and older patients who underwent surgical repair for ALCAPA after 1980 and had a median follow-up of 16 years demonstrated overall good postoperative clinical outcomes, but myocardial damage persisted over the long term. [24]  The following were among the study's findings [24] :

  • Postoperative left ventricular ejection fraction improved in infants younger than age 1 year but remain unchanged in those older than 1 year.
  • Postoperative left ventricular asynergy occurred in more than one third (37%) of patients older than 1 year but not in any of the infants younger than 1 year.
  • Both infants and older patients showed postoperative improvement in the severity of mitral regurgitation, but the difference was not significant between the two groups.
  • Both groups had postoperative perfusion defects.
  • Older patients (age >1 year) were more likely to have postoperative cardiovascular events (eg, cardiac death, arrhythmias)

Complications

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%.

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Future and Controversies

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, assessment of myocardial strain) is anticipated. [25]

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