Although uncertainty exists, in some situations, as to the optimal type of operation and a true cure may not always be possible, the outlook for patients with all types of complete transposition is poor without surgical treatment. With surgery, and in spite of current uncertainties as to the optimal type of repair, most patients can be greatly benefited, and many given a long and happy life. Even more should be possible in the future.

The vast majority of patients with complete transposition present during either the neonatal period or early infancy. Almost always the diagnosis and the categorization of associated lesions can be established by cross-sectional echocardiography. Doppler techniques usually provide enough information about flows to allow palliative or radical surgery to be undertaken without formal cardiac catheterization, because balloon atrial septostomy is carried out with echocardiographic imaging, often on the intensive care unit. Angiography is occasionally performed to visualize the pulmonary arteries or the aorta, and, if there is suspicion of a significant elevation of the pulmonary vascular resistance, it must be measured at cardiac catheterization. Neither cross-sectional echocardiography nor aortography is entirely reliable in identifying those patterns of the coronary arteries which are a contraindication to the arterial switch operation. There is, as yet, no evidence that either magnetic resonance imaging or transesophageal echocardiography are superior to more conventional methods of preoperative diagnosis in complete transposition and it seems unlikely that they will be required.

Complete transposition is a morphologic entity which exists by virtue of a concordant atrioventricular connection co-existing with a discordant connection at the ventriculoarterial level. If diagnosed in this manner, all variants can be described simply and unambiguously in terms of associated malformations along with variations in relationships and infundibular morphology.

Since the success of the arterial switch procedure is dependent on the successful translocation of the coronary arteries, a thorough understanding of the anatomic variations of the coronary arteries is essential. We reviewed the anatomy of the coronary arteries encountered in 140 consecutive cases undergoing the arterial switch procedure for complete transposition at the Heart Institute of Japan. The anatomic variations, described using the Shaher and Puddu classification, varied significantly, requiring alteration in the surgical technique.

From November 1982 to July 1989, fifty patients were treated by the REV procedure for complete transposition associated with ventricular septal defect and obstruction of the pulmonary outflow tract. The age at operation ranged from 4 months to 15 years (mean 3.8 years). The technique, based on the resection of the outlet (infundibular) septum, is described in detail. Operative mortality was 18%, essentially related to technical errors or faulty indications at the beginning of our experience. There was no late death. Six patients needed reoperation for pulmonary stenosis (2 cases) or a residual defect, in some cases associated with tricuspid regurgitation. All survivors were in excellent clinical condition. The REV procedure has fewer limitations and better results than the classical approach using Rastelli's procedure.

In this review, I describe our modification of the Mustard operation for hemodynamic correction of complete transposition which, in principle, consists of intraatrial construction of a caval venous confluence. A new design of the intraatrial baffle has been developed using Gore-Tex. Fewer complications have been encountered with this method when compared to other techniques of atrial redirection. The Mustard procedure, therefore, will retain a future role when anatomic abnormalities, or other circumstances, preclude anatomic correction at the arterial level.

We report analysis of surgical results in 110 consecutive infants and children who underwent atrial repair of simple complete transposition using the Senning operation between February 1978 and May 1990. Mean age at operation was 5.4 months ± 6.1 (range 1 week to 4 years); 75 were less than 6 months old. There were 72 males and 38 females. Operative mortality rate was 5.5%, with one late death. Average follow-up is 48.1 months with 44 followed greater than 3 years, and 27 greater than 5 years. Postoperative cardiac catheterization was performed in 48 patients. Right ventricular ejection fraction averaged 0.52 ± 0.08 and was normal in 28 patients. Response of right ventricular ejection fraction to afrerload stress was abnormal in 12 of 14 patients tested. Right ventricular ejection fraction increased normally during exercise in 6 patients, but was abnormal in 15. Mild tricuspid regurgitation was noted in 12 patients. Mild obstruction of the superior caval vein was noted in 4 patients. Baffle leak requiring reoperation occurred in one patient. Fifty-seven of 90 patients are in sinus rhythm by latest electrocardiogram. Postoperative electrophysiologic studies were performed in 34 patients, and Holter monitoring in 25. Significant arrhythmia occurred in 26 patients: 6 patients required pacemakers for slow junctional rhythm or complete heart block; 20 additional patients have a junctional rhythm. Six patients have delayed sinus nodal recovery time. At last follow-up, 88 children (98%) are in New York Heart Association functional Class I, and 2 (2%) are in Class II. The Senning operation for compete transposition can be accomplished with a low operative and late mortality. Serious baffle complications requiring reoperation are rare. Surviving patients are clinically well, but arrhythmias and depressed right ventricular function may limit their long-term functional status.

The justification for the introduction of the arterial switch procedure was based, primarily, on concern regarding the long-term ability of the right ventricle to perform as the systemic pumping chamber. In this article, the functional performance of both the systemic and pulmonary ventricles after atrial redirection procedures and the arterial switch operation will be discussed.

Concern about long-term complications after intraatrial repair of complete transposition has been used as an argument in favor of “anatomic” repair by the arterial switch operation. Late arrhythmias, including loss of sinus rhythm and the development of supraventricular tachycardias, particularly atrial flutter, are widely reported after intraatrial repair. Despite modifications of technique, the electrophysiologic substrate for arrhythmia results from the extensive atrial surgery required. Arrhythmias occur, even in the “modern surgical era” after both Mustard and Senning operations, are progressive, and appear to be inevitable. The circulation after an intraatrial repair is more vulnerable to the effects of excessive tachycardia, and this may place the patient at risk from sudden cardiac death. Current attempts at individual stratification of risk are disappointing using even aggressive electrophysiologic approaches, and a combined assessment involving hemodynamics is likely to be necessary. The electrophysiologic and arrhythmic consequences of the arterial switch operation have been less extensively researched but, as might be expected, are quite different from those seen after intraatrial repair. The atrial activation sequence is relatively undisturbed, and sinus nodal dysfunction and supraventricular arrhythmia are uncommon. Ventricular extrasystoles are the arrhythmia most consistently found during the short follow-up currently available. In the longer term, myocardial ischemia, hemodynamic disturbances and autonomic imbalance may predispose to late arrhythmia. Current evidence would suggest that the lack of clinically significant arrhythmia and the restoration of the left ventricle to the systemic circulation are significant advantages of the arterial switch operation over intraatrial repair procedures.

With the general acceptance that the arterial switch operation represents the surgical treatment of choice for complex complete transposition, an increasing number of centers are leaning towards favoring this approach for simple transposition as well. As the arterial switch procedure is a more difficult surgical procedure than the Mustard or Senning operation, the learning curve has been longer and more hazardous. Centers with large referral bases have, understandably, enjoyed a more concentrated exposure to the arterial switch operation, and are now achieving early rates of mortality as low as those quoted for atrial repairs.

In 1989, we reported the results of surgical treatment in 11 patients with complete transposition and an intact ventricular septum or restrictive ventricular septal defect who had undergone a two-stage arterial switch procedure beyond the neonatal period with a short period (median 9 days) between banding of the pulmonary trunk and repair. The most common indication for the procedure was referral to our center after the neonatal period from a geographically distant center where the arterial switch procedure was not available. Other indications were multi-organ failure in the neonatal period which contraindicated corrective surgery at that time, as well as prematurity or late development of right ventricular dysfunction, which contraindicated correction at the atrial level planned at the referral center. In this report, we describe our continuing experience.

Perhaps paradoxically, it was in the form of complete transposition with a ventricular septal defect rather than an intact ventricular septum that the arterial switch operation was first successfully applied. This was, in part, because of the poor results of the physiologic repair in the presence of a ventricular septal defect, but more because the left ventricle, in the presence of the septal deficiency, is immediately suitable for supporting postoperatively the increased workload imposed on the systemic circulation. Spurred by this success, the procedure was then extended to neonates born with complete transposition and an intact ventricular septum and is currently employed with good results in this group.