other lesions may still provide a problem Distinction from corrected transposition can sometimes be difficult in those with discordant AV connections associated with other VA connections, in those having left-sided ventricular topology in the setting of isomeric atrial appendages, in those having anterior and left-sided ascending aortas with normal atrial arrangement, and in those with anterior and right-sided aortas in the mirror-imaged situation Appropriate echocardiographic interrogation, nonetheless, should identify these variations in morphology Management Principles of Management The heterogeneity of the associated anomalies and the unpredictable nature of the systemic mRV and tricuspid valve make for complex decision-making in management Initial decisions are straightforward for severe associated anomalies such as pulmonary stenosis/atresia that require augmentation of pulmonary blood flow with a systemic shunt (or stenting of the patent arterial duct) Similarly, cases with large VSD and unobstructed pulmonary blood flow require pulmonary artery (PA) banding to control heart failure However, in terms of definitive repair, the central question in congenitally corrected transposition is whether to simply repair the associated lesions (leaving the mRV as the systemic ventricle) as a “physiologic repair” or to repair the lesions and restore the mLV to the systemic position in what is termed an “anatomic repair.” The latter is a much more complex procedure because it additionally involves switching the arterial pathways to correct the discordance VA connections, together with atrial inversion, to correct the discordant AV connections These anatomic repairs are generically referred to as the “double switch” procedures In addition to the aforementioned, there is the issue of progressive tricuspid regurgitation and mRV dysfunction, which can occur in the presence or absence of associated defects In these cases, there is an additional imperative to remove the mRV and the tricuspid valve from the systemic circulation and perform an “anatomic repair.” This is possible only if the mLV is sufficiently primed to be able to support the systemic circulation In some cases, such as in the presence of a large VSD and pulmonary artery band, the mLV has been sustained at systemic pressure and so is ideally suited to anatomic repair Conversely, in the absence of a VSD, the mLV will have become relatively involuted and unprepared to support the systemic circulation This raised the question whether the mLV could be “retrained” to work as the systemic ventricle in a similar way in which patients presenting late with regular transposition had been successfully retrained in the past It has been shown in patients with transposition and concordant AV connections that training of the mLV by banding the pulmonary trunk permitted a safe arterial switch to be performed, thus restoring the left ventricle to its role of pumping the systemic circulation.44 The same procedure has been applied successfully in patients with congenitally corrected transposition (see Fig 38.21), usually those having a degree of morphologically right ventricular failure and tricuspid valvar regurgitation It has also been shown that banding the pulmonary trunk can sometimes reduce the amount of tricuspid valvar regurgitation by realigning the ventricular septum, pushing the septal leaflet of the tricuspid valve back into the right ventricle so that it opposes the other valvar leaflets and reduces the amount of valvar regurgitation This reduction in valvar regurgitation reduces the volume loading of the mRV, helping to break into the vicious circle (Fig 38.23) Thus banding in itself may be a therapeutic option, although more usually it is used to prepare the mLV for subsequent anatomic repair.45–47 FIG 38.23 Vicious circle of morphologically right ventricular failure, exacerbated in the presence of a ventricular septal defect Morphologically Right Ventricle and Tricuspid Valve in the Systemic Circulation The management of patients with congenitally corrected transposition would be relatively straightforward were it not for the mRV being responsible for pumping the systemic circulation Physiologic restoration of normal circulatory patterns can be restored by closing ventricular septal defects, if present, relieving any obstruction in the outflow tract to the pulmonary arteries and repairing or replacing the morphologically tricuspid valve, while disturbances of AV conduction can be treated by placement of a pacemaker However, if these procedures are undertaken, leaving the mRV pumping the systemic circulation,