Stage I—The Philadelphia Approach

Initial exposure is via a median sternotomy. The thymus is removed and the pericardium opened in the midline. Lymphoid tissue between the superior vena cava and aorta overlying the trachea is removed to allow the shunt to lie properly. The diminutive aorta is fully mobilized off the pulmonary artery. The arch is mobilized into the descending aorta, beyond the ductal insertion. Tourniquets are passed around the arch vessels (except the innominate artery), and the right and left pulmonary arteries. Ao = aorta; MPA = main pulmonary artery; RA = right atrium; RV = right ventricle; SVC = superior vena cava artery.

After systemic heparinization the pulmonary artery is cannulated proximal to its bifurcation, above the pulmonary valve sinuses, and a single venous cannula is placed in the right atrium. When cardiopulmonary bypass is instituted, the snares on the pulmonary arteries are tightened to direct perfusion through the ductus arteriosis. Ao = aorta; MPA = main pulmonary artery; RA = right atrium; RV = right ventricle; SVC = superior vena cava artery.

Bypass is instituted and the patient is cooled to 18°C. During cooling the proximal anastamosis of the shunt (usually 3.5 or 4.0 mm) is created to the proximal innominate artery with 7.0 monofilament suture. It is best to cut the shunt to its appropriate length before circulatory arrest, while the structures are still filled with blood. After completion of the shunt, it is gently occluded with a hemoclip. A tourniquet is then placed around the innominate artery.

When the patient is adequately cooled, circulatory arrest is initiated. The snares on the aortic arch vessels and on the pulmonary arteries are tightened. With a clamp placed on the aorta distal to the ductal insertion, cardioplegia is administered via a sidearm connector on the arterial line. After administration of cardioplegia, the snares on the pulmonary arteries are removed.

The ductus is tied and divided, leaving the tie on the pulmonary artery side.

The atrial septum is excised through the venous purse-string or through a separate atriotomy.

The pulmonary artery is divided transversely at the origin of the right pulmonary artery. Making this division at the origin of the right pulmonary artery ensures that the connection of the PA to the aorta is distal enough that it does not interfere with the coronary arteries. The distal pulmonary artery is closed primarily or with a pulmonary homograft patch. MPA = main pulmonary artery.

The distal anastomosis of the shunt is created to the right pulmonary artery very proximally (almost at the origin of the right pulmonary artery) with 7.0 monofilament suture. The hatched line demonstrates the incision to be made starting in the diminutive ascending aorta and carried beyond the ductal insertion. RPA = right pulmonary artery.

After the aorta is opened, the ridge of ductal tissue at the coarctation is excised. In a small proportion of cases the coarctation segment is resected (inset).

The creation of the neoaorta begins with approximation of the aorta and proximal pulmonary artery with several interrupted sutures of 7.0 prolene. Occasionally a “cutback” is created into the sinus of the pulmonary artery (inset), but usually the connection is created without this slit. The purpose of the “cutback” is to prevent limitation of coronary blood flow due to distortion of the diminutive aorta. If the “cutback” is made, the commissures of the pulmonary valve are generally positioned at the level of the aortic incision.

Next the aorta is augmented with a patch of pulmonary homograft, starting distally. The tailoring of the patch geometry is complex. Generally as the suture line of the patch is brought under the arch vessels, it becomes necessary to narrow the patch posteriorly by removing a piece of homograft (shown with hatchmarks), to avoid kinking and twisting of the reconstruction. In general it is better for the patch to be slightly too narrow rather than slightly too wide.

The portion of the patch that gets sewn to the pulmonary artery needs to be further tailored so as to be concave, by removing the hatched segment, also to avoid kinking of the reconstruction.

The completed reconstruction.