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

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.

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.

Direct 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 anomalous left coronary artery from the pulmonary artery

Several reports have documented variations of the direct transfer of the anomalous left coronary artery from the pulmonary artery, as follows:

• 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 anomalous left coronary artery from the pulmonary artery to the aorta.
• Elongated flaps of the aorta and pulmonary artery are sewn side to side to create a tunnel from the anomalous left coronary artery from the pulmonary artery to the aorta.

The advantage is that none of these techniques use prosthetic material to repair the anomalous left coronary artery from the pulmonary artery.

See Medical Therapy.

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 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 anomalous left coronary artery from the pulmonary artery 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.

Standard 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.

Standard follow-up care is required after surgical repair of anomalous left coronary artery from the pulmonary artery. 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,^[6] including stress echocardiography and nuclear medicine perfusion scans, are useful to assess the patient's functional capacity postoperatively.

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%.

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).^[7] 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.

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 anomalous left coronary artery from the pulmonary artery has benefited from refinement of these surgical techniques. With appropriate diagnosis, presurgical stabilization, and team-oriented postoperative care, patients with anomalous left coronary artery from the pulmonary artery 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.