Midterm results after the arterial switch operation for transposition of the great arteries with intact ventricular septum: clinical, hemodynamic, echocardiographic, and electrophysiologic data

Right Ventricular Systolic Dysfunction in Adults With Anatomic Repair of d-Transposition of Great Arteries

The purpose of this study was to assess the prevalence of right ventricular (RV) systolic dysfunction in adults with anatomic repair of dextro-transposition of great arteries (d-TGAs), and to determine its relation to clinical outcomes across multiple domains (functional status, peak oxygen consumption, N-terminal pro-brain natriuretic peptide, and heart failure hospitalization). Adults with anatomic repair for d-TGA and with echocardiographic images for strain analysis were divided into 2 groups: (1) d-TGA status after an arterial switch operation (d-TGA-ASO group) and (2) d-TGA status after a Rastelli operation (d-TGA-Rastelli group). RV systolic function was assessed using RV global longitudinal strain (RVGLS), and RV systolic dysfunction was defined as RVGLS >-18%. We identified 151 patients (median age 21 years [19 to 28]; d-TGA-ASO group 89 [59%], and d-TGA-Rastelli group 62 [41%]). The mean RVGLS was -22 ± 4%, and 47 patients (31%) had RV systolic dysfunction. The d-TGA-Rastelli group had lower (less negative) RVGLS than that of the d-TGA-ASO group (-19 ± 3% vs -25 ± 3%, p <0.001) and higher prevalence of RV systolic dysfunction (48% vs 19%, p <0.001). RVGLS (absolute value) was associated with peak oxygen consumption (r = 0.58, p <0.001; adjusted R2 = 0.28), log-N-terminal pro-brain natriuretic peptide (r = -0.41, p = 0.004; adjusted R2 = 0.21), New York Heart Association class III/IV (odds ratio 2.29, 1.56 to 3.19, p = 0.01), and heart failure hospitalization (hazard ratio 0.93, 0.88 to 0.98, p = 0.009). RV systolic dysfunction was common in adults with d-TGA and anatomic repair and was associated with clinical outcomes. Longitudinal studies are required to determine the risk factors for progressive RV systolic dysfunction and to identify strategies for preventing RV systolic dysfunction in this population.

Major Aortopulmonary Collateral Arteries Requiring Percutaneous Intervention Following the Arterial Switch Operation: A Case Series and Systematic Review

Background: Dextro transposition of the great arteries (d-TGA) is the most common critical congenital cardiac defect surgically treated in the neonatal period by arterial switch operation (ASO). Major aortopulmonary collaterals (MAPCAs) can be present in this population and may complicate the early postoperative period. Our aim was to review our institutional data and systematically review the available literature to provide further insight on the clinical significance of MAPCAs during the early postoperative course after ASO. Methods: This is a retrospective study of patients with simple d-TGA who underwent ASO between March 1998 and September 2020 at Boston Children's Hospital. The MEDLINE, Embase, and Cochrane databases were searched from inception to June 2020. Results: Of the 671 d-TGA patients who underwent ASO at our center, 13 (1.9%) were diagnosed with MAPCAs. Five were diagnosed before ASO, while eight were diagnosed after ASO. Of these, two patients required catheterization for MAPCAs coiling during the same hospitalization on the 2nd and 11th postoperative days. The systematic review retrieved a total of 34 articles after duplicates were removed. Finally, nine studies reporting on 23 patients were deemed eligible for our analysis. The average time to MAPCAs coiling was 12 days, while the mean hospital stay was 36 days. Conclusions: MAPCAs should be included in the differential diagnosis of ASO complicated by cardiac or respiratory failure, or pulmonary hemorrhage acutely postoperatively. Once managed, recovery of these patients is predictable, and mortality is low. Further studies investigating the diagnostic value of echocardiography and the long-term outcomes of these MAPCAs are necessary.

Prenatal Delineation of Coronary Anatomy in Dextro-Transposition of Great Arteries

Background

Dextro-transposition of the great arteries (D-TGA) is the second-most common cyanotic congenital heart disease with variable coronary artery anatomy. The arterial switch procedure has revolutionized outcomes for this defect, with coronary anatomy being a key determinant of both short- and long-term outcomes following surgical repair. The assessment of coronary anatomy is usually undertaken in the postnatal period by transthoracic echocardiography, with assessment prenatally not being well studied. We sought to assess the feasibility of delineating the coronary arteries on fetal echocardiograms in a small cohort of patients followed prenatally.

Methods

This was a retrospective review of fetuses with D-TGA from 2008 to 2018. Patients with prenatal diagnosis of D-TGA were reviewed for the assessment of coronary artery anatomy. Details of coronary artery anatomy diagnosed prenatally were compared with postnatal transthoracic echocardiograms and intraoperative findings.

Results

Thirty-four fetuses with findings of D-TGA on prenatal echocardiograms were reviewed. 14/34 fetuses had attempted delineation of coronary artery anatomy, with average gestational age of 28 weeks (range 23-31 weeks) at the time of diagnosis. Two-dimensional and color Doppler imaging of the coronary arteries on both short and long axis images were performed, with complete delineation being possible in ~ 86% of fetuses. These findings were confirmed postnatally.

Conclusions

Fetuses with D-TGA can have variable coronary artery anatomy which drives postnatal outcomes. Our study describes a cohort of patients with D-TGA wherein coronary artery anatomy was assessed. We demonstrate that coronary artery evaluation is feasible prenatally with optimal imaging techniques, being more successful after 25 weeks' gestation. The potential knowledge of dangerous variants can help with referral to centers of excellence for appropriate postnatal management and facilitate prenatal care accordingly.

Primary Arterial Switch Operation for Late Referral of Transposition of the Great Arteries with Intact Ventricular Septum in the Current Era: Do We Still Need a Rapid Two-Stage Operation?

Objective:

We introduced primary arterial switch operation for the patient with transposition of great arteries and intact ventricular septum (TGA-IVS) who had more than 3.5 mm of posterior left ventricle (LV) wall thickness.

Methods:

Between January 2013 and June 2015, a total of 116 patients underwent arterial switch operation. Of the 116 patients, 26 with TGA-IVS underwent primary arterial switch operation at more than 30 days of age.

Results:

The age and body weight (mean ± SD) at the operation were 120.4 ± 93.8 days and 4.1 ±1.0 kg, respectively. There was no hospital mortality. The thickness of posterior LV wall (preoperation vs postoperation; mm) was 4.04 ± 0.71 versus 5.90 ± 1.3; P < .0001; interval: 11.8 ± 6.5 days. The left atrial pressure (mm Hg; postoperative day 0 vs 3) was 20.0 ± 3.2 versus 10.0 ± 2.0; P < .0001; and the maximum blood lactate level (mmol/dL) was 4.7 ± 1.4 versus 1.4 ± 0.3; P < .0001, which showed significant improvement in the postoperative course. All cases had delayed sternal closure. The patients who belonged to the thin LV posterior wall group (<4 mm [preoperative echo]: n = 13) had significantly longer ventilation time (days; 10.6 ± 4.8 vs 4.8 ± 1.7, P = .0039), and the intensive care unit stay (days) was 14 ± 9.2 versus 7.5 ± 3.5; P = .025, compared with thick LV wall group (≥4.0 mm: n = 13).

Conclusions:

The children older than 30 days with TGA-IVS can benefit from primary arterial switch operation with acceptable results under our indication. However, we need further investigation for LV function.

The Concept of the Arch Window in the Spiral Switch of the Great Arteries

When the arterial switch operation includes the Lecompte maneuver, the arterial trunks are reconnected in parallel, rather than the spiral fashion observed in the normal heart. Thus, although the ventriculo-arterial connections are hemodynamically corrected, the anatomic arrangement cannot be considered normal. We hypothesized that, if feasible, it would be advantageous to restore a spiral configuration for the arterial trunks. In 58 patients, we reconstructed the arterial trunks such that, postoperatively, the pulmonary channel spirals round the aorta, passing to either the right or the left, and branches posteriorly. We compared the outcomes with those in 95 patients undergoing a standard non-spiraling operation over the same period. Average follow-up was 8.2 ± 4.5 years. The estimated 10-year survival was similar in the cohorts, at 94.7 % for those with spiraling trunks, as compared to 90.4 % for those with parallel outflow tracts. Reoperation-free survival at 10 years was not significantly different (87.6 vs. 90.5 %). Supravalvar pulmonary stenosis, aortic neo-coarctation, or left bronchial stenosis, however, was encountered in one-eighth of those undergoing a standard operation. None of these complications occurred in those patients who, postoperatively, had spiraling outflow tracts (P = 0.002). Reconstruction of spiraling trunks after the arterial switch has, thus far, avoided the complications of supravalvar pulmonary stenosis, neo-aortic kinking, or bronchial stenosis. The spiraling arrangement prevents compression of the pulmonary vessels and bronchial tree by the aorta, since it provides a wide window in the new aortic arch.

Outcomes after Arterial Switch Operation for Simple Transposition

Without intervention, babies born with transposed great arteries (TGA) are doomed to a rapid death. Jatene and coworkers deserve the credit for performing the first successful arterial switch operation (ASO) in a patient with TGA and ventricular septal defect (VSD) in 1975. Since then ASO has become the procedure of choice in most medical centers. This review article summarizes the historical aspects of arterial switch operation and assesses this procedure's outcomes.

Midterm outcome of primary arterial switch operation beyond six weeks of life in children with transposition of great arteries and intact ventricular septum

BACKGROUND

We have previously reported our experience in primary arterial switch operation (ASO) in children more than six weeks with transposition of great arteries and intact ventricular septum (TGA/IVS). The upper age limit for performing an ASO in these children is not yet settled and reports regarding outcome of ASO in these children are few. In this prospective observational study, we report the midterm results of children with TGA-IVS older than six weeks undergoing primary ASO.

METHODS

A total of 109 children aged more than 6 weeks with median age of 60 days (range 42-3,000 days), with regressed left ventricle underwent primary ASO. Extracorporeal membrane oxygenation was used in 20% (22 of 109) of them; 90.8% (99 of 109) of children who survived were prospectively followed, with a mean follow-up of 28 months (range 18-84 months).

RESULTS

Two late deaths occurred, and survival in the remainder was estimated to be 98% at seven years. The incidence of aortic regurgitation (AR) was found to have a decreasing trend with freedom from AR approaching 100% by 34 months. The left ventricular shape and function returned to normal within one to three months following surgery. None of these children had any rhythm disturbances or evidence of myocardial ischemia.

CONCLUSIONS

Primary ASO can be safely performed in children with regressed ventricle, irrespective of age with encouraging results. The midterm results of these children are comparable in terms of survival and freedom from complications associated with preserved ventricle.

Functional assessment for congenital heart disease

Significant improvement in survival of children with congenital cardiac malformations has resulted in an increasing population of adolescent and adult patients with congenital heart disease. Of the long-term cardiac problems, ventricular dysfunction remains an important issue of concern. Despite corrective or palliative repair of congenital heart lesions, the right ventricle, which may be the subpulmonary or systemic ventricular chamber, and the functional single ventricle are particularly vulnerable to functional impairment. Regular assessment of cardiac function constitutes an important aspect in the long-term follow up of patients with congenital heart disease. Echocardiography remains the most useful imaging modality for longitudinal monitoring of cardiac function. Conventional echocardiographic assessment has focused primarily on quantification of changes in ventricular size and blood flow velocities during the cardiac cycles. Advances in echocardiographic technologies including tissue Doppler imaging and speckle tracking echocardiography have enabled direct interrogation of myocardial deformation. In this review, the issues of ventricular dysfunction in congenital heart disease, conventional echocardiographic and novel myocardial deformation imaging techniques, and clinical applications of these techniques in the functional assessment of congenital heart disease are discussed.

Monomorphic sustained ventricular tachycardia late after arterial switch for d-transposition of the great arteries: ablation in the sinus of valsalva

We describe the case of a young boy with d-transposition of the great arteries (TGA) that was surgically corrected with an arterial switch operation, who presented with sustained ventricular tachycardia (VT) that was successfully ablated at the embryologic pulmonary artery-related sinus of Valsalva (SV). Although the VT mechanism is still uncertain, the presence of mid-diastolic potentials during VT and postsystolic potentials during sinus rhythm argue for a re-entrant mechanism.

Left ventricular contractile reserve after arterial switch operation for complete transposition of the great arteries: an exercise echocardiographic study

AIMS

This study tested the hypothesis that left ventricular (LV) contractile reserve is altered in patients after arterial switch operation (ASO) for complete transposition of the great arteries (TGA) by non-invasive determination of LV force-frequency relationship (FFR).

METHODS AND RESULTS

Thirty-two patients aged 16.2 ± 2.1 years and 22 healthy controls were studied. M-mode parameters, transmitral early (E) and late (A) diastolic velocities, and tissue Doppler-derived systolic (sm), early (em), and late (am) diastolic mitral annular velocities were determined at baseline and during submaximal exercise testing. The LV myocardial isovolumic acceleration (IVA) was measured at different heart rates during exercise for derivation of LV FFR and the average slope of IVA increment with heart rate. At baseline, patients had significantly greater E velocity, E/A and E/em ratios, shorter E deceleration time, and reduced mitral annular sm, em, and am velocities (all P < 0.05), but similar IVA (P = 0.29) compared with controls. During exercise, sm and em remained significantly reduced (P < 0.001), and LV IVA became lower (P < 0.001) in patients. The average FFR slope was significantly lower in patients (0.039 ± 0.019 vs. 0.070 ± 0.024 m/s(2) bpm, P < 0.001). The weighted average FFR curve of patients was flattened compared with the reported positive FFR reference curve based on a healthy paediatric cohort (P < 0.0001). Patients with variant compared with those with usual coronary arterial anatomy had significant flattening of FFR (P < 0.001) and a reduced FFR slope (P = 0.007).

CONCLUSION

In adolescents and young adults after ASO, exercise stress revealed reduced LV contractile reserve, which is worse in those having variant coronary arterial anatomy.

Effect of prostaglandin duration on outcomes in transposition of the great arteries with intact ventricular septum

OBJECTIVE

To study the effects of duration of preoperative prostaglandin E1 (PGE) exposure on perioperative outcomes of the arterial switch operation in patients with transposition of the great arteries with an intact ventricular septum.

DESIGN

Retrospective chart review.

SETTING

Pediatric cardiac intensive care unit in a tertiary care children's hospital.

PATIENTS

All patients with transposition of the great arteries with an intact ventricular septum from 1995 to 2008.

OUTCOME MEASURES

Inotropic score was calculated for all patients in the first 5 postoperative days and maximum inotropic score was recorded. Length of postoperative mechanical ventilation, fluid balance, mechanical ventilation time, as well as intensive care unit and hospital stay were recorded for all patients.

RESULTS

Study population included 59 patients, 41 (69%) underwent balloon atrial septostomy. PGE was used in 52 patients, median exposure of 59 hours, range 0 to 272 hours. Longer preoperative PGE exposure was associated with longer preoperative mechanical ventilation (P < .001). There was no association between preoperative PGE duration and cardiopulmonary bypass time, cross-clamp time, or total hospital stay. Patients with longer preoperative PGE exposure had a lower postoperative inotrope score (10 vs. 15 P = .02).

CONCLUSION

Greater preoperative PGE exposure was associated with prolonged preoperative mechanical ventilation. Longer PGE exposure was associated with lower postoperative inotrope requirements. Aggressive efforts to avoid or shorten PGE infusion duration may not be warranted in this population.

Long-term outcomes after an arterial switch operation for simple complete transposition of the great arteries

BACKGROUND AND OBJECTIVES

Although coronary artery obstruction, aortic insufficiency (AI), and pulmonary stenosis (PS) have been reported after arterial switch operation (ASO), limited long-term studies on ASO exist. Our study aimed to examine long-term outcomes after ASO for simple complete transposition of the great arteries (TGA).

SUBJECTS AND METHODS

All 108 patients with simple complete TGA who underwent ASO at Seoul National University Children's Hospital between 1987 and 2004 were enrolled. We retrospectively reviewed the patients' medical records and the results of various functional and imaging studies.

RESULTS

Among 108 cases of ASO for simple TGA, 96 have been followed-up through the present time (mean follow-up duration was 11.7+/-8.6 years: range= 4 to 23 years). The 20-year rates of freedom from significant AI, PS, and coronary obstruction were 78.6%, 67.8%, and 95.8%, respectively. AI showed a tendency to progress as follow-up time increased in 21.4% of the population studied (p=0.014); however, AS, PS, and PI showed no such progression. Late coronary artery occlusion was not associated with the initial coronary arterial pattern. Re-operations were done for 13 patients (13.5%) at an average of 8+/-4.3 years after ASO. The survival rate was 96%, while the re-operation-free was 90% at 10 years and 83% at 20 years. Most patients showed normal physical growth with good activity {98%; New York Heart Association (NYHA) class 1 activity} and normal development (96%).

CONCLUSION

Although most patients showed normal physical growth and development after successful ASO, meticulous long-term follow-up is necessary because of progressive AI and coronary complications.

Determinants of exercise capacity after arterial switch operation for transposition of the great arteries

Patients who undergo the arterial switch operation for transposition of the great arteries (TGA) are at risk of reduced exercise capacity, with most reports focusing on chronotropic incompetence as the cause. Residual right ventricular outflow tract (RVOT) obstruction is relatively common after the arterial switch operation, but its effect on exercise capacity is unknown. We studied 60 patients (44 males, age 13.3 +/- 3.4 years) who had undergone a neonatal arterial switch operation using the cardiopulmonary exercise test and transthoracic echocardiography. The peak exercise oxygen uptake (VO(2)), and heart rate were recorded and are expressed as the percentage of predicted values. The greatest velocity detected by echocardiography across the pulmonary valve, pulmonary trunk, or pulmonary branches was used in the analysis as an index of RVOT obstruction. The peak VO(2)% was 84 +/- 15%, and the peak heart rate percentage was 97 +/- 8%. Of the 60 patients, 29 had an abnormal peak VO(2)% (< or =84%) and 3 (5%) had an abnormal peak heart rate percentage (< or =85%). The maximal RVOT velocity was 2.3 +/- 0.6 m/s, and it correlated with the peak VO(2)% (r = -0.392, p = 0.004). On multivariate analysis, the presence of residual RVOT obstruction (p = 0.0007) was the only variable associated with a reduced peak VO(2)%. Patients with a RVOT maximal velocity > or =2.5 m/s had a lower peak VO(2)% than those with lower velocities (p <0.0001). No relation was found between age at testing and the peak VO(2)%. In conclusion, a reduced exercise capacity is relatively common in children and young adults who have undergone an arterial switch operation, but it does not decrease with age. The presence of residual RVOT obstruction seems to have an effect on exercise capacity.

Ventricular function in patients with transposition of the great arteries operated with arterial switch

The study aim was to investigate ventricular function at long-term follow-up in patients operated with arterial switch for transposition of the great arteries (TGAs). Although midterm results for anatomic correction of TGA are promising, there are reported minor alterations in left ventricular (LV) function possibly indicating myocardial dysfunction. Twenty-two patients with TGAs 12.4 +/- 2.3 years old operated with arterial switch were studied by magnetic resonance imaging and echocardiography. Twenty-two age-matched healthy subjects served as controls. Myocardial deformation was described by longitudinal and circumferential shortening (measured as strain and strain rate) and ventricular torsion, measured by speckle-tracking echocardiography. Although standard measurements of global systolic LV function were normal in patients with TGAs, longitudinal shortening was decreased compared with controls. Longitudinal strain was decreased in all ventricular regions except the posterior wall and most pronounced in the apical segments. LV circumferential shortening was similar in the 2 groups. Also, in the right ventricular free wall patients displayed decreased longitudinal shortening in the mid and apical segment. Moreover, LV torsion was decreased in the TGA group. Although rotation was relatively homogenous at the apical and basal levels in controls, there was greater dispersion in rotation in the patient group, with basal rotation being greatest in the inferior wall and apical rotation being greatest in the anterior wall. In conclusion, there was slightly decreased longitudinal shortening in the 2 ventricles and decreased LV torsion in patients with TGAs, although standard measurements of global ventricular function were normal.

The role of aortopulmonary collaterals after an arterial switch operation: a word of caution

This report describes the case of a neonate with dextro-transposition of the great arteries and an intact ventricular septum who required postoperative extracorporeal membrane oxygenation support for an unexplained postoperative left ventricular dysfunction after an arterial switch operation. After surgery, a large aortopulmonary collateral suspected of causing overload to the left ventricle was diagnosed. Percutaneous embolization of the aortopulmonary collateral caused prompt improvement in patient's conditions and rapid weaning from mechanical ventilation support.

Symptomatic aorto-pulmonary collaterals early after arterial switch operation

Enlarged bronchial arteries and/or systemic-to-pulmonary collaterals have been frequently demonstrated in association with transposition of the great arteries. They are usually clinically silent, although they might be large enough to cause accelerated pulmonary vascular obstructive disease or symptomatic cardiac volume overload after surgical repair. We report on a low-weight neonate with transposition of the great arteries and intact ventricular septum who showed a stormy postoperative course because of multiple aorto-pulmonary collaterals early after a successful arterial switch operation. Percutaneous coil embolization of these anomalous vessels resulted in sudden weaning from mechanical ventilation and hospital discharge in a few weeks.

Cardiac Outcome up to 15 Years After the Arterial Switch Operation

AIMS

To assess the cardiac outcome and risk factors for mortality of infants following the arterial switch operation (ASO).

METHODS

A single-centre retrospective review was conducted. Preoperative assessment, operative management and outcome was detailed for 244 patients undergoing the ASO at Green Lane Hospital for transposition of the great arteries (TGA) or double outlet right ventricle.

RESULTS

The postoperative survival at 1, 5 and 15 years was 85%, 84% and 83%, respectively. The calendar year of ASO and the presence of a ventricular septal defect (VSD) were the primary predictors of early mortality. Late mortality was associated with a side-by-side configuration of the great arteries. Re-intervention following ASO was more common in patients with prolonged cardiopulmonary bypass time.

CONCLUSIONS

Low early and late morbidity and mortality can be obtained in infants with TGA or double outlet right ventricle by definitive repair utilising the ASO.

Coronary artery pattern and age impact exercise performance late after the arterial switch operation

OBJECTIVE

The impact of coronary artery pattern on exercise performance after the arterial switch operation is unknown. The purpose of this study was to evaluate the relationship between coronary artery pattern and exercise performance late after the arterial switch operation.

METHODS

Patients who underwent the arterial switch operation and were referred for exercise stress testing between January of 1996 and April of 2005 were included. Univariate and multivariate analyses were performed to identify risk factors for lower maximum heart rate and percent of predicted peak oxygen consumption.

RESULTS

Fifty-three patients were included; 72% were male. The median age at the arterial switch operation was 5 days (1 day to 3.6 years); 32% had concurrent ventricular septal defect repair. The time from the arterial switch operation to exercise stress testing was 14.1 years (7.7-20.6 years). There were 37 patients with the usual coronary artery pattern, and 16 patients (30%) with variant coronary artery patterns. At exercise stress testing, there was no difference in respiratory exchange ratio (1.16 +/- 0.1 for both), indicating similar effort. Compared with patients with the usual coronary artery pattern, patients with variant coronary artery patterns had a significantly lower maximum heart rate (177 +/- 16 beats/min [89% predicted] vs 186 +/- 11 beats/min [93% predicted], respectively, P = .04). Percent of predicted peak oxygen consumption was not significantly different between patients with the usual coronary pattern and patients with variant coronary artery patterns (89% +/- 20% vs 80% +/- 17%, respectively, P = .12). In multivariate analysis, variant coronary artery patterns (P = .03) and ventricular septal defect (P = .004) were predictors of significantly lower maximum heart rate and were associated with a trend toward lower percent of predicted peak oxygen consumption (P < .09). Longer follow-up time was the strongest predictor of lower percent of predicted peak oxygen consumption (P < .001).

CONCLUSIONS

Variant coronary artery patterns are associated with chronotropic impairment, and longer follow-up time is the strongest predictor of diminished aerobic capacity late after arterial switch operation.

Prediction of Early Pulmonary Artery Stenosis after Arterial Switch Operation: The Role of Intraoperative Transesophageal Echocardiography

OBJECTIVES

To investigate prospectively the prediction of the neopulmonary stenosis (neo-PS) after arterial switch operation (ASO) for transposition of the great artery (TGA) with intraoperative transesophageal echocardiography (TEE).

METHODS

Infants with TGA undergoing the ASO were prospectively studied over 5 years. The neo-PS was defined when the peak flow velocity was over 3 m/s at the neo main pulmonary artery (neo-MPA) after ASO by TEE (TEEPS). Catheterization was performed if estimated peak neo-PS pressure gradient was over 40 mm Hg by transthoracic echocardiography. Balloon angioplasty was tried first and surgical reoperation was reserved for those with failed angioplasty.

RESULTS

In total 49 consecutive patients were enrolled into the cohort study. TEEPS was identified in 21 patients. For patients with TEEPS, freedom from reintervention was 28% at 1 year and 23% at 2 years. For patients without TEEPS, freedom from reintervention for PS was 92% at 1 year and 78% at 2 years. The time interval from ASO to reintervention was significantly shorter in patients with TEEPS than without TEEPS. Existence of TEEPS and non-Lecompte method were main risk factor for reintervention.

CONCLUSION

The present study demonstrated that the application of intraoperative TEE for infants undergoing ASO is very helpful in predicting the development of early postoperative neo-PS.

Monitoring the introduction of a surgical intervention with long-term consequences

Surgical innovations are often introduced for their expected long-term benefits, but the decision to abandon the existing treatment must be based on the available short-term data and rational judgment. We present a framework for monitoring the introduction of a surgical intervention with long-term consequences and failure-time endpoints. The framework is based on Bayesian methods, and formally combines study data, clinical opinion, and external evidence to construct a posterior survival function from which intuitive summary statistics can be extracted to aid decision making. It incorporates learning effects and is adaptable to a wide variety of settings. The methods are illustrated on survival data from a cohort of 325 consecutive neonates treated for simple transposition of the great arteries with either the Senning or the Switch operation during the period 1978-1998.

Is the arterial switch operation as good over the long term as we thought it would be?

Surgical intervention for hearts with transposition, defined as concordant atrioventricular and discordant ventriculo-arterial connections, has been one of the landmark achievements in the field of paediatric cardiac surgery. In the early 1950s, pioneer surgeons attempted to palliate patients with transposed arterial trunks with an early form of the arterial switch operation. As a result of initially dismal outcomes secondary to difficulties with coronary arterial transfer, the unprepared nature of the morphologically left ventricle, and primitive methods for cardiopulmonary bypass, the arterial switch was abandoned in favour of several procedures achieving correction at atrial and venous levels, culminating in the Mustard and Senning operations.1,2These innovative procedures produced the earliest surviving children with transposition. Although the atrial switch procedures achieved widespread acceptance and success during the mid-1960s through the mid-1980s, the search for an operation to return the great arteries to their normal anatomic positions continued. This pursuit was stimulated primarily by the accumulating observations in mid-to-late term follow up studies of: an increasing frequency of important arrhythmic complications, including sinus nodal dysfunction, atrial arrhythmias, and sudden, unexplained death, by the development of late right ventricular dysfunction and significant tricuspid regurgitation in a ventricle potentially unsuited for a lifetime of systemic function by a small but important prevalence of obstruction of the systemic and/or pulmonary venous pathways, and by dissatisfaction with the operative mortality in the subgroup of infants complicated by additional presence of a large ventricular septal defect.3–6As we have already discussed, a number of novel procedures to achieve anatomic correction had been described as early as 1954, but clinical success was not accomplished until 1975, when Jatene and co-workers7astounded the world of paediatric cardiology with their initial description.

Aortic valve regurgitation after arterial switch operation for transposition of the great arteries: incidence, risk factors, and outcome

OBJECTIVES

The aims of this study were to assess the prevalence and incidence of aortic valve regurgitation (AR) after arterial switch operation (ASO), its outcome, and the risk factors.

BACKGROUND

After an ASO, the long-term fate of the aortic valve is a concern as follow-up lengthens.

METHODS

Operative and follow-up data on 1,156 hospital survivors after ASOs between 1982 and December 2000 were reviewed.

RESULTS

At last follow-up (mean duration 76.2 +/- 60.5 months), 172 patients (14.9%) had an AR. Complex transposition of the great arteries, prior pulmonary banding done in 75 patients (21 with intact ventricular septum), aortic arch anomalies, AR at discharge, older age at ASO, and aortic/pulmonary size discrepancy were associated with AR. On multivariate analysis, the presence of a ventricular septal defect (VSD) or AR at discharge multiplied the risk by 2 and 4, respectively. Freedom from AR was 77.9% and 69.5% at 10 and 15 years, respectively; hazard function for AR declined rapidly and slowly increased thereafter. Reoperation from AR was done in 16 patients with one death, valvuloplasty being unsuccessful. Freedom from reoperation for AR was 97.7% and 96.8% at 10 and 15 years, respectively; hazard function slowly increased from 2 to 16 years. Higher late mortality was not associated with AR.

CONCLUSIONS

After ASO, AR was observed and was related to VSD with attending high pressure and flow and AR at discharge. Progression of AR was slow, but incidence increased with follow-up. Reoperation for AR was rare. Late aortic valve function warrants long-term monitoring.

Assessment of left ventricular function long term after arterial switch operation for transposition of the great arteries by dobutamine stress echocardiography

OBJECTIVES

To use dobutamine stress echocardiography to determine left ventricular (LV) function and wall motion of children long term after arterial switch operation (ASO) for transposition of the great arteries.

DESIGN AND PATIENTS

31 patients (24 boys) with ASO performed at a mean (SD) of 15.5 (4.3) days of life were studied at an age of 9.4 (2.0) years. All had normal coronary angiographic findings. LV echocardiographic indexes, including fractional shortening, ejection fraction, rate corrected velocity of circumferential fibre shortening (VCFc), and wall stress, as well as LV wall motion abnormalities were determined at rest and under dobutamine stress. The results were compared with those of 20 healthy age matched control participants.

SETTING

Tertiary paediatric cardiac centre.

RESULTS

Fractional shortening, ejection fraction, and VCFc were significantly lower in patients than in controls at rest (all with p < 0.001). Stress-velocity index detected impaired LV contractility in 19 (61%) patients at rest. An older age at operation (p = 0.01), longer bypass (p = 0.01) and circulatory arrest times (p = 0.045), and an unusual coronary artery pattern (p = 0.059) were associated with impaired resting LV contractility. Dobutamine stress echocardiography unmasked wall motion abnormalities in 23 (74%) patients. Exercise myocardial perfusion scan, performed in 22 patients, showed reversible myocardial perfusion defects in 17. These defects corresponded to segments of hypokinesia as detected by dobutamine stress echocardiography.

CONCLUSION

A significant proportion of children, albeit asymptomatic, had impaired baseline LV contractility and reversible myocardial perfusion defects and mild wall motion abnormalities on stress after ASO.

Two-stage arterial switch operation: is late ever too late?

Results of the two-stage arterial switch operation in 49 patients with transposition of the great arteries, performed between January 1995 and September 2000, were reviewed retrospectively. Twenty-one patients had a ventricular septal defect. Anatomical correction was carried out 21.89 +/- 9.86 months after pulmonary artery banding, with or without a modified Blalock-Taussig shunt. Hospital mortality was 8% (4 patients). During follow-up of 30.12 +/- 14.38 months, there was 1 late death and 1 patient required reoperation for pseudoaneurysm of the ascending aorta. Actuarial survival and freedom from reoperation at 5 years were 90% and 97%, respectively. Late anatomic correction (> 6 months) after the preliminary procedure can be performed with an acceptable mortality and morbidity, but undue delay may lead to left ventricular dysfunction, arrhythmias, and new aortic valve regurgitation or subaortic stenosis.

Aortopulmonary window due to balloon angioplasty after arterial switch operation

We report 2 cases of aortopulmonary window that developed after balloon angioplasty for pulmonary artery stenosis. Both patients had undergone arterial switch operations for complete transposition of the great arteries before the angioplasty. These aortopulmonary windows were repaired through elective operations. The clinical features, diagnosis, management, and proposed mechanisms of this complication are described.

Results of the arterial switch operation in neonates with transposed great arteries

BACKGROUND

The arterial switch operation is judged the best palliative operation for neonates with transposed great arteries. We aimed to assess the value of analysing a large series of unselected cases by this technically demanding operation and formulate a realistic prognosis.

METHODS

We reviewed all 432 neonates (mean age at operation 7 days, mean weight 3.25 kg) who underwent an arterial switch operation between 1987 and 1999. Follow-up (mean time: 4.9 years) was complete in 412 patients.

FINDINGS

Survival probability and freedom from reoperation was 94% and 78% at 10 years, respectively. 26 patients died, 16 because of myocardial ischaemia. Risk factors for death included early experience, low weight, associated cardiovascular malformations (especially hypoplasia of the right ventricle or aortic arch), and difficult patterns of coronary arteries. The risk of the coronary artery pattern was greatly reduced in those who had recent operations. At last follow-up, 90% of patients had normal life without treatment, and 94% a normal heart function on echocardiography.

INTERPRETATION

The arterial switch operation in neonates achieves excellent results mid-term. Obstruction of the translocated coronary arteries is responsible for most deaths and a substantial number of reoperations. Although confirmation is needed, these results allow anticipation of a favourable long-term prognosis.

Scientific, ethical, and logistical considerations in introducing a new operation: a retrospective cohort study from paediatric cardiac surgery

OBJECTIVE

To review the initial impact on mortality of infants with congenital heart disease of a new surgical technique that is now taken for granted.

DESIGN

Retrospective cohort study.

SETTING

A tertiary paediatric cardiology centre.

SUBJECTS

325 consecutive neonates with simple transposition of the great arteries admitted before, during, and after the preferred management changed from the Senning operation to the arterial switch (1978-98); and 100 consecutive neonates requiring a different neonatal open heart operation that did not change in that period.

MAIN OUTCOME MEASURES

Mortality before and early after operation reconstructed sequentially as the series evolved and retrospectively once the series was complete; actuarial survival associated with the different treatment strategies.

RESULTS

For both the transposition and the comparison group, early mortality in 1998 was lower than in 1978. During that period, however, there was a phase temporally related to the adoption of the switch operation in which early mortality for transposition increased. Actuarial survival of recent patients with "intention to treat" with arterial switch is superior to those with intention to treat with the Senning operation, as predicted when the switch operation was first adopted.

CONCLUSIONS

A period of increased hazard for individual patients may occur when a specialist community, a particular unit, and an individual surgeon are all learning a new technique concurrently. Obtaining informed consent during this time of uncertainty is helped by clarity about the objectives of treatment and availability of relevant local and international data.

Arterial switch procedure for D-transposition of the great arteries: quantitative midterm evaluation of hemodynamic changes with cine MR imaging and phase-shift velocity mapping-initial experience

PURPOSE

To evaluate cine magnetic resonance (MR) imaging and phase-shift velocity mapping for assessment of the hemodynamic relevance of stenotic segments or specific hemodynamic changes in the great vessels after an arterial switch procedure for correction of D-transposition of the great arteries.

MATERIALS AND METHODS

Twenty consecutive patients (age range, 2-17 years) with an acoustic window that was insufficient for Doppler transthoracic echocardiography were included in the study. Flow and diameter measurements of the pulmonary arterial trunk and its primary branches were performed with phase-shift velocity mapping and cine MR imaging.

RESULTS

There were good correlations between pressure gradients in the pulmonary arteries estimated with MR imaging and those measured with Doppler echocardiography (r = 0.83, n = 15) and cardiac catheterization (r = 0.90, n = 13). Cine MR imaging revealed that the diameters of the right and left pulmonary arteries decreased with the expansion of the aorta during systole, which increased the peak velocity. This temporary stenosis was more severe in the right than in the left pulmonary artery and was accompanied by a significantly (P <.05) lower volume flow in the right artery.

CONCLUSION

The anatomic situation after arterial switch repair tended to produce temporary stenoses in the primary pulmonary arterial branches, with significant changes in hemodynamics. These changes may affect the long-term outcome and go undetected with other imaging modalities.

Myocardial blood flow and coronary flow reserve late after anatomical correction of transposition of the great arteries

OBJECTIVES

Myocardial blood flow (MBF) in children late after arterial switch operation (ASO) was investigated quantitatively by positron emission tomography (PET).

BACKGROUND

In children with transposition of the great arteries (TGA), ASO is widely accepted as the management of choice. The long-term patency of coronary arteries after surgical transfer to the neo-aorta, however, remains a concern.

METHODS

Twenty-two normally developed, symptom-free children were investigated by PET with nitrogen-13 ammonia at rest and during adenosine vasodilation 10+/-1 years after ASO. A subgroup of 15 children (9+/-1 years; group A) had simple TGA and underwent ASO within 20 days after birth while 7 (13+/-3 years; group B) had complex TGA and underwent ASO and correction of associated anomalies later after birth. Ten young, healthy adults (26+/-6 years) served as the control group.

RESULTS

Resting MBF was not different between groups. After correction for the rate-pressure product as an index of cardiac work, younger children of group A had significantly higher MBF at rest compared to healthy adults (102+/-29 vs. 77+/-6 ml/100 g/min; p = 0.012) while flow in group B was not different from the other groups (85+/-22 ml/100 g/min; p = NS). Hyperemic blood flows were significantly lower in both groups after ASO compared to normals (290+/-42 ml/100 g/min for group A, 240+/-28 for group B, 340+/-57 for normals; p < 0.01); thus, coronary flow reserve was significantly lower in both groups after ASO compared to healthy adults (3.0+/-0.6 for group A, 2.9+/-0.6 for group B, 4.6+/-0.9 for normals; p < 0.01).

CONCLUSIONS

Blood flow measurements suggest decreased coronary reserve in the absence of ischemic symptoms in children late after arterial switch repair of TGA. The global impairment of stress flow dynamics may indicate altered vasoreactivity; however, the prognostic significance of these findings needs to be determined.

Direct reconstruction of the pulmonary artery during the arterial switch operation: an interesting surgical option with excellent hemodynamic results

BACKGROUND

In transposition of the great arteries, reconstruction of the neo-pulmonary artery is a challenging surgical detail during the arterial switch procedure. We present early and midterm clinical and hemodynamic results of a direct reconstruction of the pulmonary artery avoiding prosthetic and autologous material.

METHODS

Between 1990 and June 1996, a total of 189 patients underwent the arterial switch procedure because of D-transposition of the great vessels. Of them, 47 underwent direct pulmonary artery reconstruction. Mean age at operation was 5.2+/-4.1 days and mean weight was 3.75+/-0.85 kg. Simple transposition of the great arteries was present in 13, transposition of the great arteries plus ventricular septal defect in 27, and more complex forms of transposition of the great arteries in 7 patients. The great vessels were side-by-side in 4 patients and in the anteroposterior position in 43 patients. The technique of direct pulmonary reconstruction includes extensive mobilization of both pulmonary artery branches into the hilum, posterior incision of the mean pulmonary artery into the bifurcation, and resuspension of the posterior commissure of the neo-pulmonary valve. A large anastomosis without any tension is then performed, using the anterior remnant aortic sinus of Valsalva to fit out the expected size of the neo-pulmonary artery.

RESULTS

Early mortality was 8.5% (4/47) in this particular group of patients. Postoperative echocardiography was performed before hospital discharge, 3 to 6 months postoperatively, and after a mean follow-up of 24 months. Of the 43 survivors, 37 patients had a pressure gradient across the pulmonary valve of less than 15 mm Hg. Mild pulmonary stenosis (pressure gradient of 15 to 30 mm Hg) was present in 4 and more severe supravalvar stenosis (pressure gradient > 30 mm Hg) in 2 patients. After a mean follow-up of 36 months, there was one redo operation to enlarge the right ventricular outflow tract.

CONCLUSIONS

Direct reconstruction of the neo-pulmonary artery-avoiding autologous pericardium and prosthetic material-may represent an interesting option during the arterial switch operation when the great vessels lie in the anteroposterior position. This technique is simple, and the hemodynamic midterm results are very favorable. The incidence of postoperative supravalvar pulmonary stenosis is low, and there may be considerable potential for unlimited tissue growth.

Fate of the neopulmonary valve after the arterial switch operation in neonates

OBJECTIVES

The purpose of this study was to determine the incidence, risk factors, and outcomes of acquired stenosis of the neopulmonary valve after the neonatal arterial switch operation.

METHODS

Reviewed were the preoperative and follow-up echocardiograms from 136 of 288 patients undergoing the arterial switch operation for whom adequate studies were available. Pulmonary stenosis was defined as a thickened and doming pulmonary valve and a pressure gradient of 20 mm Hg or more. Transposition of the great arteries was present with intact ventricular septum in 91 patients, with a ventricular septal detect in 39, with an aortic coarctation in 5, and with double-outlet right ventricle in 1 patient. No patient had preoperative valvular abnormalities (i.e., a bicuspid valve).

RESULTS

During a median follow-up of 18 months (range <1 to 90 months), 32 patients (24%) had the development of supravalvular pulmonary stenosis, 15 (11%) with associated pulmonary valve stenosis (group I). Kaplan-Meier estimates of freedom from any intervention were 94% (95% confidence interval, 90% to 99%) at 1 year and 79% (95% confidence interval, 64% to 94%) at 5 years. The valve anulus before the arterial switch operation was significantly larger (p < 0.03) in those in whom neopulmonary valve stenosis did not develop (group II) than it was in those in whom it did (group I). At follow-up, the pulmonary valve anulus had decreased significantly in diameter in group I (p < 0.0005) and had remained larger in group II (p = 0.06) compared with normal diameter. Group I patients had the development of significant pulmonary valve hypoplasia (p < 0.03) whereas group II patients continued to have significantly larger valves compared with normal size (p < 0.0001).

CONCLUSIONS

Neopulmonary valve stenosis after the arterial switch operation is not uncommon and is associated with growth failure of the valve anulus often associated with supravalvular pulmonary stenosis.

Long-term results of arterial switch repair of transposition of the great vessels

The arterial switch operation has become the preferred surgical procedure for transposition of the great arteries worldwide. The low operative mortality at "low-risk" institutions has been well documented. The advantages of the arterial switch compared with atrial-level repairs include a lower incidence of arrhythmias and the likelihood of normal systemic ventricular function over the long term. However, the long-term sequelae of this operation must be continually evaluated, including the fate of the supravalvular pulmonary and aortic anastomoses, growth of the aortic root, competency of the neoaortic valve, patency of the coronary arteries, effects on the conduction system, and adequacy of ventricular function. These anatomic results, as well as the neurodevelopmental outcomes of these patients, are summarized in this review. Copyright 1998 by W.B. Saunders Company

Results of the Bruce treadmill test in children after arterial switch operation for simple transposition of the great arteries

Children who underwent arterial switch operation for simple transposition of the great arteries in the neonatal period are now reaching an age when exercise testing becomes feasible. This study was conducted to assess exercise tolerance and electrocardiographic response to exercise stress in 50 asymptomatic children, aged 4 to 9 years, using the Bruce walking treadmill protocol to voluntary exhaustion. Heart rate and blood pressure response to exercise stress, endurance time, and electrocardiographic changes were analyzed and compared with those of age-matched normal children. Forty-seven patients had normal exercise capacity and parameters. One patient, whose coronary angiogram showed occlusion of the left main coronary artery, developed electrocardiographic signs of myocardial ischemia during exercise. In 1 patient with a single right coronary artery ostium and in another, who underwent a neonatal internal mammary bypass graft for obstruction of the right coronary artery, the resting electrocardiogram showed ventricular premature complexes and exercise stress-induced salvos of ventricular tachycardia. We conclude that most of the children who underwent the neonatal arterial switch operation for simple transposition of the great arteries have a normal exercise capacity. Exercise testing appears to be useful in detecting ischemic damage or exercise-induced arrhythmias possibly secondary to reduced coronary flow reserve.

Angiographic study of aorta, coronary arteries, and left ventricular performance after neonatal arterial switch operation for simple transposition of the great arteries

This retrospective study attempts to assess the growth pattern of the aorta and the coronary arteries and the left ventricular function approximately 1 year after neonatal arterial switch operation for simple transposition of the great arteries. Seventy-one patients underwent cardiac catheterization and cineangiocardiography an average of 13.5 months after the operation. The diameters of aortic annulus, aorta at different sites, and coronary arteries were compared with normal ranges taken from the literature. Left ventricular systolic performance was also evaluated. Observations included the following: Neoaortic annulus and root were larger than normal, trivial or mild neoaortic regurgitation was frequently observed, and the development of aortic anastomosis was normal. One patient had unexpected coronary occlusion, one had a coronary artery fistula, and two had a hypoplastic left anterior descending coronary artery. Except in one child who underwent an internal mammary bypass graft immediately after anatomic correction, the global left ventricular performance was normal. Six patients had regional wall motion abnormalities. Our midterm results are encouraging, but potential late complications remain concerns that must continue to be evaluated in long-term follow-up studies.

[Angioplasty of residual lesions after correcting surgery of transposition of great vessels]

BACKGROUND

Surgical correction in infants born with transposition of the great arteries, venous rerouting procedure (Mustard or Senning operation) or an arterial switch operation, can be complicated by vascular narrowings. Balloon dilatation angioplasty may be the treatment for these stenotic lesions and is attempted to avoid a reoperation of these patients.

MATERIAL AND METHODS

Angioplasty was attempted in nine patients after the surgical correction of transposition of the great arteries. Senning procedure was performed in sixty-one patients; two patients (3.2%) were successfully balloon-dilated for systemic venous obstruction: superior vena caval obstruction (case 1) and inferior vena caval obstruction (case 2). Arterial switch operation was performed in forty patients, balloon angioplasty was attempted in seven patients (17.5%) who developed supravalvar pulmonary artery stenosis. Mean age at dilation was 32.5 +/- 20.7 months (range 11 to 67) in the switch arterial group. Age at dilation in the Senning group was 8 and 106 months. The balloon/stenosis diameter was 2 to 3 in the switch arterial operation and 3 to 8 in the Senning procedure.

RESULTS

Balloon dilatation angioplasty was successful in three patients with supravalvar pulmonary stenosis postarterial switch operation (mean age was 16.6 months) and reduced the peak-to-peak gradient from 78.6 +/- 36.6 mmHg to 44 +/- 15 mmHg. There was no success after angioplasty in three patients and it was not possible to cross the stenosis with the guidewire in one (mean age was 46 months). Balloon dilatation angioplasty was successful in the obstruction following Senning procedure.

CONCLUSIONS

These data indicate that although the success rate of balloon angioplasty for supravalvar pulmonary stenosis after the arterial switch operation is low, balloon angioplasty can be the first therapeutic choice owing to its low complication rate and the potential benefit of the procedure. The success rate should be higher if angioplasty is performed at a younger age after operating and a balloon of adequate size is used. Postoperative systemic venous obstructions can be successfully managed with balloon dilatation.

Coronary artery obstruction after the arterial switch operation for transposition of the great arteries in newborns

OBJECTIVES

We sought to describe a large series of coronary artery obstructions after the arterial switch operation for transposition of the great arteries and to discuss their clinical implications.

BACKGROUND

Aortic root angiography and myocardial perfusion imaging yield ambiguous results regarding the fate of the coronary artery anastomoses after the arterial switch operation. Late death related to coronary artery obstruction and growth of the translocated coronary arteries are of major concern in these patients.

METHODS

Selective coronary artery angiography was performed prospectively in a total of 165 children.

RESULTS

A total of 12 coronary occlusions, 8 major stenoses, 6 minor stenoses of the left ostium and 4 stretchings of one coronary artery were identified. Obstructions were more frequent in types D and E (p < 0.001) of the Yacoub and Radley-Smith classification. Coronary obstruction was documented in all patients with electrocardiographic and ultrasound evidence of myocardial ischemia at time of study. Early postoperative ischemia did not predict coronary artery lesion if the patient had fully recovered. Persistent or delayed myocardial ischemia was highly predictive of coronary artery lesions. The incidence of coronary artery obstruction was very high (11 of 35) in patients operated on by a rapidly abandoned technique of single-orifice reimplantation of both coronary artery ostia.

CONCLUSIONS

Selective coronary angiography is the most accurate means to assess coronary artery obstruction after the arterial switch operation. Precise diagnosis of coronary artery lesions after this operation will help to elucidate the pathogenesis, develop adequate therapeutic strategies and might indicate how to prevent coronary complications after operation.

Long-term fate of the coronary arteries after the arterial switch operation in newborns with transposition of the great arteries

OBJECTIVE

Concern continues to be expressed about the long-term impact of coronary artery translocation after the arterial switch operation for transposition of the great arteries. This study was conducted to determine the prevalence of obstructions of the translocated coronary arteries by the use of selective coronary artery angiography.

METHODS AND RESULTS

64 children (mean age 7.6 (SD) 1.5 years) who had survived an arterial switch operation underwent evaluation. They had been operated on by one surgeon and they were followed up by a single hospital. Selective coronary artery angiography was possible in 58 patients. Five patients showed occlusion or stenosis of a coronary artery: one occlusion and two stenoses of the left coronary trunk, two occlusions of the circumflex artery. The prevalence of late coronary artery complications was 7.8 (SD) 6.6% (95% CI 1.2 to -14.4%). The three patients with occlusion of one coronary artery had perioperative ischaemic complications, with associated electrocardiogram evidence of ischaemia and left ventricular dysfunction with mitral valve insufficiency. Both patients with stenosis of the left main coronary artery trunk did not have any evidence of an anomaly before catheterisation.

CONCLUSIONS

The prevalence of the late coronary artery complications after an arterial switch operation was low in this series. This accords with the view that the arterial switch operation remains the preferred treatment for such patients. Screening for late coronary artery patency should be done by using selective coronary artery angiography, because even patients who remain symptom free can have coronary artery anomalies.

Reoperation after the arterial switch operation for transposition of the great arteries

Although most children after an arterial switch operation for transposition of the great arteries have normal development and cardiac function, a few require reoperation. During the last 10 years, 68 of 753 patients who underwent arterial switch operations (9.3%) underwent 75 reoperations. Thirty underwent early reoperation (< 30 days or during the same hospital stay) and 38 underwent late reoperation. Causes for reoperation included pacemaker insertion (n = 5), left diaphragm plication (n = 4), revision for hemostasis (n = 1), mediastinitis (n = 2), superior vena cava thrombosis (n = 9), subvalvular pulmonic stenosis (n = 5), supravalvular pulmonic stenosis (n = 16), residual atrial (n = 2) or ventricular (n = 8) septal defects, isolated mitral valve insufficiency (n = 2), aortic valve insufficiency (either isolated [n = 1] or in association with mitral incompetence [n = 1] or stenosis [n = 1]), left coronary artery ostial stenosis (n = 1), and recurrent aortic (n = 6) or neoaortic (n = 4) aortic coarctation. In all but 27 patients, the residual defects were already present immediately after the completion of the arterial switch operation; however, only patients with critical lesions were reoperated on early. Interventional catheterization procedures were performed when indicated; however, they only postponed inevitable reoperation. Successful relief of superior vena cava thrombosis was achieved by atriojugular bypass grafting in two patients, by early open thrombectomy in six patients, and by direct patch angioplasty of the superior vena cava once. Patch plasty for subvalvular or supravalvular pulmonic stenosis was carried out in 21 patients, septal defect closure was carried out in nine patients, and pulmonary artery banding was performed in one patient with criss-cross atrioventricular relationship and multiple ventricular septal defects. Valve repair was performed in all five patients with either isolated or combined aortic and mitral valve dysfunction. One patient with left coronary ostial stenosis underwent a patch enlargement of this ostium. Recoarctation was repaired by end-to-end anastomosis in eight patients and by a subclavian flap and a patch angioplasty in one patient each. Seven patients underwent a second reoperation for supravalvular pulmonary stenosis (n = 3), mitral valve replacement (n = 1), ventricular septal defect closure (n = 1), and recurrent coarctation (n = 2). There were six intraoperative (8.8%) and two late deaths. All early deaths occurred after early reoperations.(ABSTRACT TRUNCATED AT 400 WORDS)