10.2 Presentation in Adulthood
Physiologic repair resulting in connections of the left ventricle to the pulmonary artery and the right ventricle to the aorta
Double switch operations resulting in connections of the right ventricle to the pulmonary artery and the left ventricle to the aorta
No initial surgical intervention because of an absence of atrial and ventricular shunts and non-obstructive pathways from the left ventricle to the pulmonary artery and the right ventricle to the aorta
Patients with remote physiologic repair by VSD closure and reconstruction of the left ventricular to pulmonary artery pathway (pulmonary valvotomy or left ventricle-pulmonary artery conduit) generally present with pulmonary outflow tract or conduit stenosis. They may or may not have accompanying tricuspid regurgitation, depending on the degree of right ventricular dysfunction.
Patients with remote physiologic and anatomic repair fall into two categories: double switch operation and atrial baffle/Rastelli operation. The preoperative conditions determine the type of anatomic repair that can be performed, and both have long-term complications originating from the original operation. For instance, patients who had the double switch operation (arterial switch and atrial baffle operations) may develop baffle leaks or obstructions, neoaortic regurgitation, supravalvar pulmonary stenosis, or coronary obstructions. Patients who had the atrial baffle/Rastelli operation may develop baffle leaks or obstructions, left ventricular outflow tract (LVOT) obstruction, and conduit stenosis/regurgitation that almost assuredly will require conduit replacement.
Patients who had a balanced ccTGA circulation without remote operations typically had no intracardiac shunts and mild or absent LVOT obstruction. These patients do well for many years into adulthood, with scattered reports of survival into the sixth and seventh decades, but some develop progressive significant pulmonary or subpulmonary valve stenosis that requires intervention to avoid coronary malperfusion, ventricular dysfunction, and severe cyanosis. Treatment options for these problems are controversial and not resolved.
To understand the pre-existing conditions that may require operative revision, a complete review of the surgical procedures will help the clinician unravel the problems that these patients experience in adulthood.
10.3 Classic Physiologic Repair for Congenitally Corrected Transposition of the Great Arteries and Ventricular Septal Defect without Pulmonary Stenosis
10.4 Physiologic Classic Repair of Congenitally Corrected Transposition of the Great Arteries and Ventricular Septal Defect with Left Ventricular Outflow Tract Obstruction (Pulmonary Stenosis)
When the time comes for conduit replacement, two issues become important. The first is that the left ventricle becomes decompressed, thereby allowing the interventricular septum to bow to the left and cause tricuspid regurgitation. The second is unwanted coronary artery injury owing to left ventricular free wall incision for the larger conduit. This problem usually does not happen in the right ventricle, because the right anterior ventricular wall is not rich with large coronary arteries. The left ventricular free wall is a different issue, however, as it contains many branches arising from the course of the right coronary artery. Interruption of these vessels during conduit replacement can have an additive negative effect on ventricular interaction and overall ventricular function. Cardiac transplantation may be the only solution for this unfortunate series of events.
10.5 Physiologic Repair by Ventricular Septal Defect Closure, Pulmonary Valvotomy, and Bidirectional Glenn Shunt for Congenitally Corrected Transposition of the Great Arteries, Ventricular Septal Defect, and Moderate Pulmonary Stenosis
10.6 Double Switch Operation for Congenitally Corrected Transposition of the Great Arteries, Ventricular Septal Defect, and no Pulmonary Stenosis
The atrial switch-arterial operation was introduced to create an anatomic and physiologic repair of ccTGA in circumstances where there is no valvar PS, with or without an associated VSD. The physiologic considerations that are necessary for this operation to be successful are largely the same as for arterial switch as applied to transposition of the great arteries. Patients with ccTGA, VSD, and no PS may have their operation delayed for a few months, assuming that the VSD is large enough to affect left ventricular systemic pressure. Those patients with ccTGA and no PS may require a neonatal double switch or two-stage repair using preparatory pulmonary artery banding for left ventricular training before the double switch operation. The drawbacks of this preparatory approach center around the neoaortic valve, which is subject to valvar regurgitation after preparatory pulmonary artery banding. The long-term results with these clinical strategies are yet to be determined. Nevertheless, the concept of double switch to accomplish physiologic and anatomic repair is very appealing despite the long-term possibilities of atrial pathway obstructions, atrial arrhythmias, neoaortic regurgitation, and coronary artery problems.