Medium-Term Outcome of Anatomically 
Repaired Congenitally Corrected 
Transposition: The Double Switch Operation

Rajesh Sharma, Shiv K Choudhary, Rajnish Juneja, Anil Bhan,  
Shyam S Kothari, Anita Saxena, Panangipalli Venugopal

Cardiothoracic Centre, All India Institute of Medical Sciences, New Delhi

Background: The double switch operation is emerging as the procedure of choice for congenitally corrected transposition of the great arteries. However, rhythm disturbances in the postoperative period are rarely discussed. 

Methods and Results: Eighteen survivors who underwent corrective surgery for congenitally corrected transposition of the great arteries were followed up. Patients in group I (n=8), who also had a ventricular septal defect and pulmonary stenosis, had undergone the Senning plus Rastelli operation. Patients in group II (n=10), who did not have pulmonary stenosis, had undergone the Senning and arterial switch operation. The patients were followed up by periodical clinical examination, echocardiography and 24-hour Holter monitoring. In group I, follow-up ranged from 24 to 66 months (mean 44 months). There was no late death and all the patients are symptom free. There was no significant atrioventricular valve regurgitation and left ventricular function was normal. There were no rhythm disturbances. In group II, follow-up ranged from 2 to 72 months (mean 48 months). There were 2 late deaths due to atrial tachyarrhythmia and residual pulmonary hypertension 36 and 8 months after the procedure, respectively. One patient had significant mitral regurgitation and required mitral valve replacement. Three patients had recurrent atrial/junctional tachyarrhythmia; one of them was lost to follow-up after 1 year while another died of resistant atrial tachyarrhythmia. The third patient underwent mitral valve replacement for severe mitral regurgitation and developed complete heart block necessitating a permanent pacemaker implantation.

Conclusions: Though good long-term results are obtained following the double switch operation, the problem of atrial arrhythmias still needs to be addressed suitably. (Indian Heart J 2002; 54: 390–393)

Key Words: Transposition of the great arteries, Double switch operation, Atrial tachyarrhythmias

Uniformly poor long-term results with the conventional surgical approach to congenitally corrected transposition of the great arteries (CCTGA), i.e. repair of associated defects without addressing the issue of atrioventricular and ventriculo-arterial discordance, have prompted various investigators to embark upon the pathway of anatomic repair for this lesion.1–10 These investigators have proved that despite the prolonged intraoperative support times involved and the intricate nature of the repairs, it is possible to achieve satisfactory early outcome. However, reports of longer follow-up are limited 2,4,10 and it still remains to be proven if the double switch operation will withstand the test of time.

We present the follow-up data of patients who survived the double switch operations of surgery conducted between 1994 and 2001 at our institute.

Methods

The follow-up data of 8 survivors of the Senning plus Rastelli procedure for CCTGA with associated ventricular septal defect (VSD) and pulmonic stenosis (PS) (group I), and 10 early survivors of the Senning plus arterial switch procedure for CCTGA without PS (group II) were reviewed. In group I, the age range was 3–16 years (median 5 years) while in group II, it was 9 months–18 years (median 4 years). In group II, 7 patients had systemic level pulmonary artery pressure and 1 patient had undergone pulmonary artery banding previously. Associated lesions in both the groups are shown in Table 1. 

Table 2 shows the operative procedures in both the groups. The intraoperative technique has been described in an earlier publicaion on this subject.7 The important changes incorporated subsequently have been: (i) minimizing the excision of the limbus of the atrial septum during the Senning procedure to avoid injury to the sinus node artery; and (ii) liberal use of pericardial extension on coronary buttons whenever button rotation seems to be excessive.

All the survivors were evaluated clinically, echo-cardiographically and by long-lead electrocardiograms and 24-hour Holter recording at 6-monthly intervals.

Results

Senning plus Rastelli Group (group I): There was 100% follow-up of the patients in group I, extending from 24 to 66 months (mean 44 months). There was no late death. All the survivors are asymptomatic and off all medications, and continue to be in stable sinus rhythm with no significant arrhythmias on Holter recording.Echocardiography revealed left ventricular (LV) ejection fractions ranging between 45% and 55% (mean 51%). None of the patients had any significant regurgitation at either atrioventricular valve. Conduit gradients ranged between 16 and 36 mmHg. 

Arterial switch plus Senning Group (group II): The follow-up of patients in group II is 90% complete and ranges from 2 to 72 months (mean 48 months). There were 2 late deaths 36 and 8 months following surgery, respectively. One patient has been lost to follow-up. 

Echocardiographic evaluation at various stages of follow-up had revealed the presence of moderate mitral regurgitation (MR) in 1 patient which had resulted from intraoperative avulsion of a mitral chorda during VSD closure. This patient recently presented with worsening of MR and cardiomegaly. All the other patients had no MR and 3 patients had only mild tricuspid regurgitation. The LV ejection fraction measured at multiple occasions was found to remain stable between 60% and 70% (mean 63%) in the entire group.

Cardiac rhythm: Three patients were being followed up for recurrent episodes of atrial tachyarrhythmias (AT). Over the past 2 years, one of these patients has been lost to follow-up while 1 reported with gross congestive heart failure resulting from AT with a ventricular rate >250/min. The latter succumbed despite maximal medical therapy. The third patient also had severe MR for which she underwent replacement of the mitral valve, which resulted in third-degree atrioventricular (AV) block requiring permanent pacemaker insertion. Although she continues to have atrial flutter, the ventricular rate is now well controlled. 

Lung disease: A 2-year-old boy with severe left AV valve regurgitation and a prepared morphological LV (preoperative pulmonary artery pressure 2/3rd that of the systemic) underwent successful anatomic correction. However, the coexistent hyper-reactive airway disease that he also suffered from got exacerbated 5 months following discharge. The resulting pulmonary hypertension led to right heart failure and death, despite normal LV function and no other residual anatomic defect. 

Thus, in group II, only 7 out of 10 early survivors are doing well at a mean follow-up period of 38 months. 

Discussion 

The disadvantages of the conventional surgical approach to CCTGA and associated lesions are well taken care of by anatomic repair. The morphologic left ventricle has performed well as the systemic ventricle, while the switch of the mitral valve (right-sided AV valve) to its systemic role has abolished the tricuspid (systemic AV) regurgitation wherever it was a major issue. A drop in the pulmonary artery pressure, as normally occurs with VSD closure, also renders the tricuspid valve, even if structurally abnormal, reasonably competent without the need for any direct intervention. In line with the above, prolonged intraoperative support times have not reflected on early outcome.

The focus in long-term outcome has, however, shifted from anatomic and functional issues to the area of cardiac rhythm disturbances in 3 of our 18 long-term survivors. These three started experiencing AT after a mean period of 12 months following surgery (range 5–18 months). Specifically, 2 of the patients had atrial flutter and supraventricular tachycardia intermittently, while the third had only junctional tachycardia. Each of these episodes was controlled with great difficulty and was directly responsible for at least 1 patient’s demise. Loss of sinus rhythm soon after surgery was a marker for late atrial arrhythmias. This is reminiscent of similar episodes of arrhythmia following atrial-level repairs of simple transposition and following univentricular repair.11–13 None of the patients who had stable sinus rhythm in the early postoperative period have so far reported any episodes of tachycardia. Of note is the fact that none of the patients in group I with Senning plus Rastelli type repairs had any of these arrhythmias, and Holter recordings, even in those who had postoperative junctional rhythm, were devoid of significant atrial arrhythmias.

Possible explanations may include existence of bypass pathways, which may enable re-entry in CCTGA.14 However, none of these patients gave any history of arrhythmias preoperatively. The more plausible explanation may be that atrial-level repair gave rise to re-entrant pathways predisposing to AT. The atrial component of the double switch was always predicted to be the Achilles’ heel in all anatomic repairs of CCTGA 4 though this complication has never been reported with the frequency and intensity with which we have encountered it. 

The predilection of the group with pulmonary hypertension for postoperative AT could be explained by the probability that all the patients underwent repair when some pulmonary vascular disease would have already set in (mean age 5 years in these 3 patients, range 3–8 years). The setting of incomplete regression of pulmonary hypertension and the resultant right atrial distension could act as a predisposing factor for a pre-existing substrate (atrial suture lines, sinus node injury, re-entrant circuits).  

Reddy et al.3 have suggested the addition of a bidirectional Glenn shunt to reduce the atrial suture lines as a preventive measure against future atrial arrhythmias.However, while this may be a useful adjunct in the group of patients with diminished pulmonary blood flow, it is not conceivable in patients who may have labile pulmonary vasculature which, in our experience, happens to be the only group exhibiting this complication. In an attempt to reduce atrial arrhythmias in these patients, we have recently reduced the extent of excision of the atrial limbus to avoid injury to the sinus node artery. The in situ pericardial reconstruction of the pulmonary venous atrium allows an atrial limbic remnant at the base of the superior vena cava to the right atrial junction without any resultant superior vena caval obstruction as almost the entire right atrial free wall goes into construction of the systemic caval pathway. All three patients in whom this modification was used demonstrated stable sinus rhythm immediately after surgery and have so far not shown any AT. 

Another potential problem in patients with severe tricuspid regurgitation or pulmonary hypertension with resulting or coexisting lung disease may be the inability of the morphologic right ventricle to cope with the residual pulmonary hypertension, especially if it is episodic. This problem is peculiar to populations where delayed referral is common and is clearly illustrated by the patient in whom persistent lung disease and pulmonary hypertension resulted in fatal right heart failure 8 months following successful repair. Ideally, a timely repair before irreversible pulmonary changes set in would avoid this situation altogether. However, faced with this patient group in which pulmonary hypertension is likely to persist postoperatively, in our opinion, a classical repair, leaving the morphological LV in the pulmonary position, may result in better outcome as it would be best adapted to handle any residual pulmonary artery pressure elevations.  

In summary, anatomic repair of CCTGA seems to have lived up to all the indications for which it was introduced, i.e. left AV valve regurgitation and systemic ventricular failure.15,16 However, the problem of atrial arrhythmias still needs to be addressed suitably if we are to fully satisfy the expectations from this modality of treatment.

Correspondence: 
Dr Rajesh Sharma, 
B-404 Adarsh Palace, 
Block-5, Jaya Nagar, 
Bangalore. 
e-mail: rsharmacvs@hotmail.com

References

  1. Stumper O, Wright JG, De Giovanni JV, Silove ED, Sethia B, Brawn WJ. Combined atrial and arterial switch procedure for congenital corrected transposition with ventricular septal defect. Br Heart J 1995; 73: 479–482

  2. Imamura M, Drummond-Webb JJ, Murphy DJ Jr, Prieto LR, Latson LA, Flamm SD, et al. Results of the double switch operation in the current era. Ann Thorac Surg 2000; 70: 100–105 

  3. Reddy VM, McElhinney DB, Silverman NH, Hanley FL. The double switch procedure for anatomical repair of congenitally corrected transposition of the great arteries in infants and children. Eur Heart J 1997; 18: 1470–1477

  4. Imai Y. Double-switch operation for congenitally corrected transposition. Adv Card Surg 1997; 9: 65–86 

  5. Karl TR, Weintraub RG, Brizard CP, Cochrane AD, Mee RB. Senning plus arterial switch operation for discordant (congenitally corrected) transposition. Ann Thorac Surg 1997; 64: 495–502

  6. Helvind MH, McCarthy JF, Imamura M, Prieto L, Sarris GE, Drummond-Webb JJ, et al. Ventriculo-arterial discordance: switching the morphologically left ventricle into the systemic circulation after 3 months of age. Eur J Cardiothorac Surg 1998; 14: 173–178

  7. Sharma R, Bhan A, Juneja R, Kothari SS, Saxena A, Venugopal P. Double switch for congenitally corrected transposition of the great arteries. Eur J Cardiothorac Surg 1999; 15: 276–281; discussion 281–282

  8. Imai Y, Seo K, Aoki M, Shin’oka T, Hiramatsu K, Ohta A. Double-Switch operation for congenitally corrected transposition. Semin Cardiovasc Surg Pediatr Card Surg Annu 2001; 4: 16–33 

  9. Yamagishi M, Imai Y, Hoshino S, Ishihara K, Koh Y, Nagatsu M, et al. Anatomic correction of atrioventricular discordance. J Thorac Cardiovasc Surg 1993; 105: 1067–1076 

  10. Yagihara T, Kishimoto H, Isobe F, Yamamoto F, Nishigaki K, Matsuki O, et al. Double switch operation in cardiac anomalies with atrioventricular and ventriculoarterial discordance. J Thorac Cardiovasc Surg 1994; 107: 351–358

  11. Deanfield J, Camm J, Macartney F, Cartwright T, Douglas J, Drew J, et al. Arrhythmia and late mortality after Mustard and Senning operation for transposition of the great arteries. An eight-year prospective study. J Thorac Cardiovasc Surg 1988; 96: 569–576

  12. Kirjavainen M, Happonen JM, Louhimo I. Late result of Senning operation. J Thorac Cardiovasc Surg 1999; 117: 488–495 

  13. Balaji S, Gewillig M, Bull C, de Leval MR, Deanfield JE. Arrhythmias after the Fontan procedure. Comparison of total cavopulmonary connection and atriopulmonary connection. Circulation 1991; 84 (Suppl): III162–167

  14. Bharati S, Rosen K, Steinfield L, Miller RA, Lev M. The anatomic substrate for preexcitation in corrected transposition. Circulation 1980; 62: 831–842

  15. Lundstrom U, Bull C, Wyse RK, Somerville J. The natural and "unnatural" history of congenitally corrected transposition. Am J Cardiol 1990; 65: 1222–1229

  16. Termignon JL, Leca F, Vouhe PR, Vernant F, Bical OM, Lecompte Y, et al. "Classic" repair of congenitally corrected transposition and ventricular septal defect. Ann Thorac Surg 1996; 62: 199–206