Primary surgical repair for truncus arteriosus

Repair of simple truncus arteriosus.
(A) The infant is placed on cardiopulmonary bypass with either bicaval cannulation or single venous cannulation in the right atrium. The aorta is cannulated as distally as possible to allow cross-clamping proximal to the aortic cannulation site for division of the pulmonary arteries from the truncal vessel. Snares are placed on the right and left pulmonary arteries to prevent pulmonary overcirculation during warming and to allow delivery of cardioplegic solution to the myocardium. After cardioplegia is achieved, the snares are released from the pulmonary arteries and the pulmonary bifurcation is excised from the back of the truncal artery, with care being taken to avoid the origin of the left coronary artery posteriorly. An incision is made in the right ventricle, with care being taken to avoid major epicardial coronary branches and the base of the truncal valve.
(B) The defect in the main trunk is closed with a patch of pulmonary homograft material or pericardium. Cardioplegic solution is then administered to observe any leaking of the suture line because the area will be difficult to expose after complete repair. The VSD is exposed through the ventriculotomy incision. There is no muscle rim typically present at the superior margin of the VSD, and therefore the patch is secured to the epicardial portion of the ventriculotomy incision superiorly.
(C) The VSD is closed with an ovoid patch of polyethylene terephthalate (Dacron) material sewn to the superior margin of the ventriculotomy incision. Typically, a rim of muscle is present inferiorly between the VSD and the tricuspid valve septal leaflet, and in these patients a running suture line can be created that avoids the conduction tissue. If the muscle bridge is not present, the inferior margin of the suture line is carried along the base of the septal tricuspid valve leaflet on the right ventricular aspect to avoid the conducting tissue.
(D) The pulmonary arteries are reconstructed with a pulmonary homograft. To prevent kinking of the homograft with distention, it is trimmed 2 to 3 mm distal to the commissural attachments of the pulmonary valve. To provide an adequate anastomosis and size match to the pulmonary bifurcation using a large pulmonary homograft of 12 to 18 mm in diameter, an incision is carried into the origin of the right pulmonary artery for a short distance and more significantly into the left pulmonary artery if additional opening is necessary. An anastomosis is then created between the pulmonary homograft and the pulmonary bifurcation.
(E) The pulmonary homograft is then sewn proximally to the superior aspect of the ventriculotomy incision for approximately one-third of its circumference. If adequate muscle is present on the pulmonary homograft, it can be sewn directly down to the right ventricular outflow tract. However, if inadequate tissue is present, the outflow tract is augmented with a gusset of polytetrafluoroethylene (PTFE) material, as shown in the inset, to create a gentle take-off of the homograft from the right ventricular outflow tract to avoid compression.