Left-Side Pulmonary Vein Obstruction After Arterial Switch Operation in Infants with D-Transposition of the Great Arteries

We describe two cases of left-side pulmonary vein obstruction observed after the arterial switch operation (Jatene) for D-transposition of the great arteries. This appears to be related to left-sided pulmonary vein obstruction occurring coincidently with D-transposition of the great arteries, rather than a consequence of arterial switch operation.     

Growth After Neonatal Arterial Switch Operation for D-Transposition of the Great Arteries

The objective of this study was to evaluate growth in infants with d-transposition of the great arteries (d-TGA) who underwent switch operation (anatomical correction) in the early neonatal period. Growth data (at birth and 1, 3, 6, 12, and 24 months of age) were retrieved in 23 infants with d-TGA who survived the operation without major complications. Measures were transformed into z scores and compared with normative data for age. Following surgery, infants showed low z scores for weight, height, and head circumference. Weight and height showed a trend to reach normal ranges between 6 and 12 months of age, and the z scores were positive at 24 months. z scores for head circumference were still negative at 24 months of age. No dietary interventions were implemented during this period, and the infants were fed their own mothers' milk or, before discharge, high-calorie, preterm formula. Following anatomical correction for d-TGA in the early neonatal period, infant growth shows a characteristic pattern, with parameters normalized by 12 months of age in most cases. Head growth shows a different pattern, although gross motor development seems unaffected.     

Late-Onset Pulmonary Arterial Hypertension After a Successful Atrial or Arterial Switch Procedure for Transposition of the Great Arteries

Common complications after surgery for transposition of the great arteries (TGA) include systemic ventricular dysfunction and arrhythmia after atrial baffle repair (AB) and outflow tract stenosis or regurgitation after the arterial switch (AS). Severe pulmonary hypertension (PHT) is a rarely reported problem after AB and AS. In this study we sought to evaluate the frequency of late onset severe PHT following surgical repair for TGA. We report 3 cases, 2 after AB and 1 after AS, describe the frequency of this complication and treatment response, by comparing the response to pulmonary vasodilators in this group of patients to that of idiopathic or connective tissue disease (CTD) related PHT. We currently follow 85 patients ≥17 years of age with repaired TGA; 77 after AB and 8 after AS. 3.5% of our adult congenital heart disease patients with TGA have developed late severe PHT. None of these patients demonstrated clinical improvement with Bosentan at 6 months, however 2 of 3 were stabilised with the addition of Sildenafil to initial therapy. The third patient died 4 months after the diagnosis of severe PHT, whilst waiting for heart-lung transplantation, despite Bosentan, Sildenafil and inotropic support. By contrast, of 37 patients with idiopathic or CTD related PHT commenced on Bosentan as initial therapy, 32 (86.5%) demonstrated a clinical response at 6 months; the other patients had Sildenafil as added therapy after 6 months. Our data suggest that patients with TGA and late onset PHT are less likely to achieve a clinical response on pulmonary vasodilator monotherapy (P = 0.006). Whilst more investigation is needed, our experience suggests an aggressive clinical course, often requiring combination PHT treatment.     

Late Manifestation of Coarctation of the Aorta After Arterial Switch Operation for D-Transposition of the Great Arteries With Intact Ventricular Septum

We describe an infant with D-transposition of the great arteries with an intact ventricular septum who developed coarctation of the aorta 13 days after arterial switch operation. A mildly hypoplastic aortic isthmus was present on echocardiogram at the time of the arterial switch operation, but there was no echocardiographic or clinical evidence of coarctation of the aorta.     

影响大动脉调转术治疗完全性大动脉转位患儿死亡的危险因素

目的 探讨影响大动脉调转术(ASO)治疗完全性大动脉转位(D-TGA)患儿死亡的危险因素,以提高手术治愈率.方法 选择本院2001年9月-2009年3月行ASO、≤4月龄D-TGA婴儿135例,确定潜在危险因素后收集其临床资料,利用单因素分析及多因素Logistic回归分析,最终确立ASO术中及术后30 d内死亡的危险因素.结果 D-TGA患儿术中或术后30 d内死亡27例,病死率为20%(27/135例),其中2001-2003年死亡4/8例(50%),2004-2006年死亡16/44例(36.4%),2007-2009年死亡7/83例(8.4%).Logistic回归分析提示冠状动脉异常(OR=22.476,P=0.041)、体外循环时间(OR=1.024,P=0.000)、主动脉阻断时间(OR=0.982,P=0.019)、术后严重低心排综合征(OR=8.166,P=0.023)、术后肾衰竭(OR=9.809,P=0.046)是行ASO治疗D-TGA患儿死亡的主要影响因素.结论 伴有冠状动脉异常、体外循环及主动脉阻断时间长、术后并发严重低心排综合征和肾衰竭是预测行ASO治疗D-TGA患儿死亡的重要指标.     

Exercise Performance in Patients with D-Loop Transposition of the Great Arteries After Arterial Switch Operation: Long-Term Outcomes and Longitudinal Assessment

The first patients to undergo a successful arterial switch operation (ASO) for d-transposition of the great arteries (D-TGA) are now entering their fourth decade of life. Past studies of ASO survivors’ exercise function have yielded conflicting results. We therefore undertook this study to describe the current function of ASO survivors, to identify factors related to inferior exercise performance and to determine whether their exercise function tends to deteriorate over time. A retrospective cohort study was designed examining all patients with D-TGA after the ASO who underwent comprehensive cardiopulmonary exercise testing (CPET). Patients with palliative surgery prior to ASO, ventricular hypoplasia or severe valvar dysfunction were excluded from the study. Data from CPETs in which the peak respiratory exchange ratio was <1.09 were also excluded. We identified 113 patients who met entry criteria and had 186 CPX at our institution between 1/2002 and 1/2013; 41 patients had at least 2 qualifying CPX. Mean age at the time of the initial test was 17 ± 1 year. Peak oxygen consumption (VO2) averaged 84 ± 2 % predicted. Peak VO2 was lower among patients with repaired ventricular septal defects (82 ± 4 vs. 86 ± 3 % predicted; p < 0.05) and among patients with ≥ moderate right-sided obstructive lesions (77 ± 5 vs. 87 ± 3 % predicted; p < 0.05). Surgery prior to 1991 was also associated with a lower peak VO2 (81 ± 3 vs. 87 ± 3 % predicted; p < 0.01). The mean % predicted peak heart rate was 92 ± 1 %, with no significant difference between any of the subgroups. Non-diagnostic exercise-induced STT changes developed in 10 patients (12 studies). In the subgroup with at least 2 exercise tests, the annual decline in % predicted peak VO2 was quite slow (?0.3 % points/year; p < 0.01 vs. expected normal age-related decline). The exercise capacity of ASO survivors is well preserved and is only mildly reduced compared to normal subjects. Moreover, there is only a slight deterioration in exercise capacity over time. VSD repair, residual right-sided obstructive lesions, and earlier surgical era are associated with worse exercise performance. Peak heart rate was preserved with no significant change in follow up testing.     

Successful Use of Covered Stent to Treat Superior Systemic Baffle Obstruction and Leak After Atrial Switch Procedure

Progressive dyspnea and cyanosis occurred in a 41-year-old patient status after Mustard atrial switch repair for transposition of great arteries. Cardiac catheterization and magnetic resonance imaging revealed the association of superior limb systemic venous baffle obstruction and leaks with right-to-left shunting. He underwent successful dilation of the venous channel and obstruction of baffle leaks by using a covered stent.     

Exercise Studies in Patients with Transposition of the Great Arteries After Atrial Repair Operations (Mustard/Senning): A Review

Exercise evaluation studies of patients after atrial repair surgery for transposition of the great arteries, as in tetralogy of Fallot, represent only a small fraction of the 3970 Medline references (1966 to mid-1997) concerning this congenital heart lesion. We have abstracted data from 27 studies from 20 institutions reporting on measurements during exercise on work capacity, heart rate response, respiratory gas exchange, or radionuclide/radiographic systemic ventricular ejection fraction measurements in addition to resting pulmonary function measurements. These studies provide almost uniform general conclusions that even after 20 or more years of follow-up (1) most patients ``report' that they are asymptomatic in performing usual levels of physical activities; (2) significant abnormalities are present, often in more than half of the patients studied, in one or more of the exercise measurements when compared to control subjects; and (3) the diminished exercise performance is related to a diminished cardiac output, results from diminished stroke volume but is also related to a blunted heart rate response.     

Long-Term Follow-up Assessment After the Arterial Switch Operation for Correction of Dextro-Transposition of the Great Arteries by Means of Exercise Myocardial Perfusion-Gated SPECT

The arterial switch operation (ASO) is the preferred technique for correcting transposition of the great arteries, but translocation and reimplantation of the coronary arteries can produce myocardial ischemia. This report aims to describe the authors’ experience with exercise single-photon emission computed tomography (SPECT) used to evaluate myocardial perfusion. Exercise-rest gated-myocardial perfusion SPECT was performed for 69 patients (49 boys; median age, 9 years; 5th percentile [6.4 years] to 95th percentile [15.6 years]), 64 of whom were asymptomatic 9.98 ± 3.20 years after ASO. During exercise testing, the patients reached 9.85 ± 3.05 metabolic equivalents (METs) and a median heart rate of 160 beats per minute (bpm), 5th percentile (106 bpm) to 95th percentile (196 bpm). Whereas 61 patients (88.41 %) had normal myocardial perfusion, 2 patients (2.9 %) had reversible defects, and 6 patients (8.7 %) had fixed defects. All the patients with perioperative ischemic complications (4/4, 100 %) had myocardial perfusion defects, whereas four patients (4/65, 6.15 %) without ischemic complications had abnormal perfusion (p = 0.0005). Age at the time of surgery did not differ significantly (p = 0.234) between the patients with perfusion defects and those with normal study results. No significant difference was observed between the patients who had an A coronary pattern (left coronary artery originating from the left sinus and the right coronary artery originating from the right sinus, n = 47) and those who had a non-A coronary pattern (n = 22) (p = 1). The high rate for normality of exercise myocardial perfusion in our study suggests that myocardial perfusion gated-SPECT should be reserved for patients who have experienced perioperative ischemic complications or those with symptoms, at least during the first 10 years after the surgery.     

Factors Associated With Prolonged Recovery After the Arterial Switch Operation for Transposition of the Great Arteries in Infants

This study aimed specifically to identify the predictors of prolonged recovery after the arterial switch operation for transposition of the great arteries in infants. The clinical records of all infants admitted to the surgical intensive care unit (SICU) between January 2000 and March 2011 after an arterial switch operation were retrospectively reviewed. The cohort was divided into a prolonged recovery group that included all patients who exceeded the 75th percentile for duration of SICU stay and a standard recovery group that included all the remaining patients. Of the 102 patients in the final analysis, 31 experienced prolonged recovery. The median SICU stay was 18 days (range, 14?C58 days) for the patients in the prolonged recovery group and only 8 days (range, 5?C13 days) for the patients in the standard recovery group. After univariate analysis, a stepwise logistic regression model analysis was used to compare the demographic data as well as the pre-, intra-, and postoperative variables between the two groups. Of all the variables analyzed, high postbypass serum lactate level [odds ratio (OR), 2.610; 95?% confidence interval (CI), 1.464?C4.653; p?=?0.039], need for larger volume of resuscitation fluid (OR, 3.154; 95?% CI, 1.751?C5.682; p?=?0.018), and noninfectious pulmonary complication (OR, 2.844; 95?% CI, 1.508?C5.363; p?=?0.025) were identified as independent risk factors for prolonged recovery among infants undergoing an arterial switch operation for transposition of the great arteries.     

Assessment of Progressive Changes in Exercise Performance in Patients with a Systemic Right Ventricle Following the Atrial Switch Repair

There is a high prevalence of right ventricular dysfunction and reduced exercise performance in survivors of atrial switch repair for transposition of the great arteries. However, it is not known whether the impairment in exercise performance is progressive. We performed paired comparison of exercise performance in 28 patients who underwent two serial incremental exercise tests at an interval of 5.0 ± 1.4 years between the two tests (age 11.5 ± 3.7 years at first test, 16.4 ± 3.6 years at second test). There was no change in the chronotropic response between the two tests. However, there was a reduction in both the peak VO₂ (32.5 ± 8.3 vs 29.6 ± 5.7 ml/kg/min, p= 0.05) and anerobic threshold (22.1 ± 5.1 vs 18.3 ± 4.2 ml/kg/min, p < 0.01) with time. Furthermore, there was a decline in the O₂ pulse (oxygen uptake/beat) at anaerobic threshold (% predicted value 95 ± 23% vs 82 ± 23%, p= .02), O₂ pulse at a heart rate of 140 (% predicted value 100 ± 30% vs 85 ± 19%, p= 0.02), and the maximum O₂ pulse (z value −0.27 ± 1.31 vs −1.27 ± 1.16, p < 0.01) when compared to growth-related normal values. We conclude that there is a progressive reduction in aerobic response to exercise in patients with a systemic right ventricle. The maintenance of chronotropic response suggests that the stroke volume response of the systemic right ventricle during exercise does not increase commensurate with somatic growth.     

Pulmonary Venous Obstruction in the Atrial Switch Operation: A Forgotten Complication

The reported case involved a 7-year-old girl with congenitally corrected transposition of the great arteries (ccTGA) and situs inversus who after surgical management experienced symptoms of dyspnea and left-sided obstructive heart disease. Her symptoms, chest X-ray, and cardiac catheterization demonstrated pulmonary venous obstruction, a known but rare complication associated with intra-atrial baffle obstruction. The incidence of the reported disorder, the follow-up assessment, and the current literature regarding complications of Senning/Mustard surgery are discussed in the context of patients with ccTGA.     

Subclavian Steal Syndrome in Anomalous Connection of the Left Subclavian Artery to the Pulmonary Artery in D-Transposition of the Great Arteries

Several reports have documented the occurrence of an isolated left subclavian artery in association with both tetralogy of Fallot and double-outlet right ventricle. In certain cases a congenital subclavian or pulmonary artery steal syndrome exists in which the left subclavian artery is connected to the main pulmonary artery via a ductus arteriosus. We describe a subclavian steal syndrome secondary to anomalous origin of the left subclavian artery from the pulmonary artery in d-transposition of the great arteries in a patient with Spondylocostal dysostosis (SCD). Cardiac anomalies are rare in SCD and this constellation of findings have not previously been described.     

Evaluation of Right Ventricular Performance Long After the Atrial Switch Operation for Transposition of the Great Arteries Using the Doppler Tei Index

Right ventricular (RV) dysfunction may occur in patients after the atrial switch operation for d-transposition of the great arteries (d-TGA) and can be an important complication. Noninvasive assessment of RV function using echocardiography is necessary for following up these patients. We evaluated RV function using the Doppler Tei index (RV Tei index). The RV Tei index measures the ratio of total time intervals in isovolumetric contraction and relaxation to the ejection time. The subjects consisted of 33 patients who had undergone the atrial switch operation for d-TGA (the atrial switch group) (mean age, 21 ± 4 years), 10 patients with pulmonary artery stenosis after the arterial switch operation for d-TGA (the arterial switch group) (mean age, 17 ± 1 years), and 10 patients with a normally structured heart as a control group (mean age, 26 ± 7 years). The RV Tei index (0.65 ± 0.16) was significantly higher in the atrial switch group than in the arterial switch group (0.29 ± 0.07) and the control group (0.29 ± 0.01) (p < 0.05). The fractional area change of the RV obtained from the four-chamber view in the atrial switch group showed a significant negative correlation with the RV Tei index (r = −0.58, p < 0.01). The RV Tei index increased with increasing severity of the NYHA functional class. In the moderate/severe tricuspid regurgitation group, it was significantly higher than in patients with none/trivial tricuspid regurgitation. We conclude that the RV Tei index is useful for evaluating RV junction long after the atrial switch operation for d-TGA.     

Great Vessel Root and Artery Dimensions in Transposition of the Great Arteries Repaired With Atrial Switch Operation

To describe great-vessel dimensions in patients with D-loop transposition of the great arteries (TGA) who have undergone atrial switch operation (ATSO). Patients who have undergone arterial switch operation for TGA have a high incidence of dilation of the neoaortic root. The incidence and degree of great artery dilation in patients who have undergone ATSO for TGA has not previously been described. A retrospective database review identified patients with TGA and intact ventricular septum who underwent ATSO at <1 year of age with cardiac magnetic resonance (CMR) within the previous 5 years (n = 39). A control group of patients referred for CMR with normal findings was identified for comparison (n = 40). Measurements of the annulus, root, sinotubular junction, and great vessels were performed, and interobserver/intraobserver variability was assessed. Median age of subjects at ATSO was 3 months (range 1–12) with median age at CMR of 29 years (range 18–40). For aortic measurements, mean z scores (± SDs) for patients relative to body surface area (BSA)–adjusted normal controls were as follows: annulus 1.41 (0.80), root 2.04 (1.48), sinotubular junction 2.16 (1.26), and great vessel 1.86 (1.53). For pulmonary measurements, similar values were as follows: annulus 1.82 (1.42), root 3.25 (2.01), sinotubular junction 2.47 (1.79), and great vessel 3.96 (3.08). In all cases, the p value was <0.001, and no confidence interval included the value 0. Adult patients with TGA repaired with ATSO in infancy have a greater incidence of dilation of both great vessels, particularly the pulmonary artery. These results may indicate abnormalities in the vascular structure of both great arteries in TGA that may predispose to progressive arterial dilation.     

Cardiorespiratory Responses to Exercise After Anatomic Repair of Atrioventricular Discordance with Abnormal Ventriculoarterial Connection

We evaluated exercise tolerance and cardiorespiratory responses to exercise in patients with atrioventricular discordance (AVD) and abnormal ventriculoarterial connection after anatomic repair. Cardiopulmonary treadmill exercise testing with gas measurement was done 62 times in 19 patients with AVD who had undergone anatomic repair at the National Cardiovascular Center. Exercise duration, oxygen uptake ( O₂) and heart rate at anaerobic threshold and peak, and oxygen pulse during exercise were significantly lower in patients with AVD after anatomic repair than in controls. Carbon dioxide ventilatory equivalent during exercise was worse in patients with AVD after anatomic repair than in controls. Percentage peak O₂ significantly correlated positively with percentage peak oxygen pulse and tended to correlate positively with the heart rate increments. Patients with AVD after anatomic repair exhibit impaired responses of heart rate and oxygen pulse with lower exercise capacity. Careful attention should be paid to patients with AVD after anatomic repair in terms of their functional capacity as well as other postoperative complications.     

Left Ventricular Function in Patients with Transposition of the Great Arteries Operated with Atrial Switch

In patients operated with atrial switch for transposition of the great arteries (TGA), the left ventricle (LV) supports the pulmonary circulation and is thus pressure unloaded. Evaluation of LV function in this setting is of importance, as LV functional abnormalities have been documented and might contribute to development of symptoms. The ventricular contraction pattern in 14 Senning-operated TGA patients and 14 healthy controls was studied using tissue Doppler and magnetic resonance imaging. In the subpulmonary LV free wall, longitudinal strain was greater than circumferential strain (−23.6 ± 3.6% vs. −19.1 ± 3.2%, p = 0.002) as in the normal right ventricle (RV) (−30.7 ± 3.3% vs. −15.8 ± 1.3%, p < 0.001), but opposite to findings in the normal LV (−16.5 ± 1.7% vs. −25.7 ± 3.1%, p < 0.001). Subpulmonary strain and strain rate values were intermediate between those in the normal LV and RV. Ventricular free-wall torsion was reduced in the subpulmonary LV compared with both the normal LV (5.7 ± 3.2° vs. 16.7 ± 5.6°, p < 0.001) and RV (5.7 ± 3.2° vs. 11.4 ± 2.6°, p < 0.05). Furthermore, early diastolic filling of the subpulmonary LV differed from that of the normal LV. The subpulmonary LV displayed predominantly longitudinal shortening, as did its functional counterpart, the normal RV. However, the degree and rate of both longitudinal and circumferential shortening were intermediate between those of the normal LV and RV. This could represent a partial adaptation to the reduced pressure load. Decreased ventricular torsion and diastolic abnormalities might indicate subclinical ventricular dysfunction.     

Surgical Repair for D-Transposition of the Great Arteries Associated With an Aortopulmonary Window Using the Fenestrated Ventricular Septal Defect Patch as a Safety Adjunct

Transposition of the great arteries with a ventricular septal defect and an associated aortopulmonary window is a rare anatomic combination having a high risk for pulmonary hypertension. Arterial switch with closure of the ventricular septal defect and repair of the aortopulmonary window is the procedure of choice, but a postoperative pulmonary hypertensive crisis is a common occurrence associated with significant morbidity and mortality. This report describes one case of such an anatomic lesion, which was repaired successfully with a fenestrated ventricular septal defect patch as an adjunct to decrease the risk of a postoperative pulmonary hypertensive crisis.     

Comparison of Bilateral Pulmonary Arterial Level and Diameter in Transposition of the Great Arteries

In normal anatomy, the left pulmonary artery (LPA) is usually situated higher than the right pulmonary artery (RPA); however, transposition of the great arteries (TGA), the LPA is not always situated higher than the RPA. This study was performed to clarify the relative position of the RPA and the LPA in transposition of the great arteries (TGA) as well as the implications. We reviewed 101 angiograms of patients with TGA (age 4.1 ± 1.2 months). The width of the RPA, the LPA, and the pulmonary trunk (PT) were measured just before their first branch in the frontal view. They were classified into four groups according to the ratio between the RPA and the PT (RPA/PT). The initial courses of the LPA and the RPA were compared and defined according to their height in the frontal view, and the preferential flow (or not) to the RPA was recorded. The equation of hydrodynamics was applied to evaluate the bifurcation angle. Both PAs were the same size in all cases. Forty-eight patients (47.5 %) had a RPA/PT diameter ratio < 0.49. The LPA coursed higher than the RPA in the majority of cases (81 [80.2 %]); in a minority of cases the LPA and RPA were at the same level (6 [5.9 %]); and in some cases the RPA coursed higher than the LPA (14 [13.9 %]). Patients with a high degree of PA hypoplasia tended to have both PAs at the same level or a higher-positioned RPA. Autopsy (1 of 3 cases) showed a posterior ridge against the bronchus in the higher RPA. Hydrodynamic calculation showed that the greater the angle between the RPA/PT, the greater the preferential flow. Preferential flow to the RPA in TGA did not necessarily result in LPA hypoplasia before its first branch. Higher RPA position relative to the LPA was associated with greater flow in it against the posterior bronchus. This situation was more prevalent in patients with severe PA hypoplasia.