Absent Pulmonary Valve Repair

Before cardiopulmonary bypass is commenced, the aorta, proximal arch, and head vessels are widely mobilized. Standard cardiopulmonary bypass is instituted with direct bicaval cannulation. The aorta is cannulated as high as possible. A left atrial vent is inserted through the right pulmonary veins. Moderate hypothermia with cold crystalloid cardioplegia is applied. The SVC is dissected free and the azygos vein is transected to improve mobility of the SVC. The left and right pulmonary arteries, including the first pulmonary artery branches in the hilum of each lung, are dissected free and mobilized. Care is taken to stay away from the phrenic nerve on both sides. Traction of the aorta by a small retractor or tape facilitates exposure of both pulmonary arteries. Ao = aorta; LA = left atrium; LPA = left pulmonary artery; MPA = main pulmonary artery; RA = right atrium; RPA = right pulmonary artery; RV = right ventricle; SVC = superior vena cava; v = vein.

After clamping the aorta and delivering of cardioplegia, a short (10-15 mm) transannular longitudinal incision is made in the right ventricular outflow tract. The parietal band is transected to enlarge the right ventricular outflow tract. PA = pulmonary artery; RV = right ventricle; VSD = ventricular septal defect.

(A) If the parietal band is properly divided, a transatrial approach offers very good exposure for the closure of the ventricular septal defect, even in neonates. If necessary, extended resection of right ventricular outflow tract can be accomplished working through the tricuspid valve as well. (B) A continuous suture technique and Dacron patch are preferred. Alternatively, in neonates with a very fragile myocardium, a pledgeted suture technique should be used. The foramen ovale in newborns and small infants is left open. TV = tricuspid valve; VSD = ventricular septal defect. (Redrawn from Bove.)

The transverse aortotomy is performed above the aortic valve commissures. A short tubular segment of the aorta is resected. This maneuver brings the future ascending aorta down and to the left. Resection of aorta, especially in newborns, might be omitted, to avoid too close a relationship between the aorta and the trachea and left bronchus.

The pulmonary artery is transected above the annulus. Care is taken to stay away from left coronary artery. If the left pulmonary artery is too long, the pulmonary trunk is obliquely cut toward the left pulmonary artery. LCA = left coronary artery; LPA = left pulmonary artery; RPA = right pulmonary artery.

The transected pulmonary artery is mobilized, if necessary, and brought anterior to the aorta. At this point, end-to-end anastomosis of the ascending aorta is performed. Care is taken not to compress the right coronary artery by the translocated pulmonary artery. In particular, the right pulmonary artery must be mobilized adequately to avoid undue tension on the right coronary artery.

A direct connection between the pulmonary artery and right ventricular outflow tract is accomplished using a continuous suture technique (the aorta is cut off for clarity).

The right ventricular outflow tract is enlarged and reconstructed by use of a transannular pericardial patch treated with glutaraldehyde, with the aim of achieving a normal Z-value for the annulus. The newly created right ventricular outflow tract should have growth potential.

Especially in newborns and small symptomatic infants, anterior plication of the pulmonary artery is performed to decrease wall tension and prevent later development of aneurysmal dilation of the pulmonary artery. Triangular segments of the anterior wall of each branch pulmonary artery and part of the anterior wall of the pulmonary artery trunk are excised. An appropriately chosen Hegar dilator is used to guide the extent of the resection of the pulmonary artery and the magnitude of plication. An anterior wall resection may be combined with posterior wall plications of the main and both pulmonary arteries. RPA = right pulmonary artery.

The final outcome of translocation of the pulmonary artery with direct connection to the right ventricle, patch reconstruction of the right ventricular outflow tract, and anterior plication of the pulmonary arteries. If a homograft is not used, the reconstruction has growth potential. The usual monitoring lines and temporary atrial and ventricular pacing wires are always placed.

Homograft insertion (recommended in symptomatic newborns) or monocusp valve placement is performed, if necessary. A short pulmonary homograft is orthotopically placed; the proximal anastomosis is supplemented with a roof of autologous pericardium, which has been treated with glutaraldehyde.