Ann Thorac Surg 2009;88:1948-1951. doi:10.1016/j.athoracsur.2009.08.051
© 2009 The Society of Thoracic Surgeons
Original Articles: Pediatric Cardiac
Arterial Switch for Transposition of the Great Vessels and Taussig-Bing Anomaly After Six Months of Age
Bin Feng, MDa,*,
Yinglong Liu, MDb,
Shenshou Hu, MDb,
Xiangdong Shen, MDb,
Xu Wang, MDb,
Hua Wang, MDa,
Bo Ming, MDa
a Department of Thoracic and Cardiovascular Surgery, The Second of Chuanbei Clinical Medical College and Nanchong Central Hospital, Nanchong, People's Republic of China
b Pediatric Center of Cardiac Surgery, Cardiovascular Institute and Fu Wai Hospital, Chinese Academy of Medical Science and Beijing Union Medical College, Beijing, People's Republic of China
Accepted for publication August 20, 2009.
* Address correspondence to Dr Feng, Department of Thoracic and Cardiovascular Surgery, The Second of Chuanbei Clinical Medical College and Nanchong Central Hospital, Sichuang Province, Nanchong, 637000, People's Republic of China (Email: fsn9977{at}yahoo.com.cn).
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Abstract
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Background: Indications and outcomes of the arterial switch operation in children who are older than 1 month of age and have transposition of the great arteries plus ventricular septal defect or Taussig-Bing anomaly were studied.
Methods: Arterial switch operation was performed in 68 children between January 2000 and December 2008. Thirty infants (1 to 6 months old) had transposition of the great arteries plus ventricular septal defect or Taussig-Bing anomaly (group A), and 38 children older than 6 months of age had transposition of the great arteries plus ventricular septal defect or Taussig-Bing anomaly (group B). The preoperative pulmonary artery pressure in group B was significantly higher than that in group A (46.5 ± 16.3 mm Hg and 31.3 ± 8.6 mm Hg, respectively; p < 0.05). Arterial switch operation was performed under general anesthesia, hypothermia (18° to 22°C), and low-flow (50 mL · kg–1
· min–1) extracorporeal bypass circulation. Concomitant cardiac anomalies were treated during the same surgical session.
Results: Average extracorporeal circulation time, aortic clamping time, postoperative overall hospitalization, and intensive care unit duration were not significantly different between the two groups (p > 0.05). The operative mortality rate in group A was 10.0% (3 of 30 patients) and in group B, 7.9% (3 of 38 patients; p > 0.05). Follow-up examinations in the surviving 62 patients after a mean of 13.5 ± 7.9 months (range, 0.5 to 56 months) showed significantly improved cardiac function without any long-term complications, and no cases of death occurred during this period.
Conclusions: Arterial switch operation shows satisfactory operative outcome of transposition of the great arteries plus ventricular septal defect or Taussig-Bing anomaly in children older than the age of 6 months with moderate-to-severe pulmonary hypertension.
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Introduction
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The arterial switch operation (ASO) is a logical anatomic arterial correction for the treatment of complex congenital heart defects with anomalies of the ventriculoarterial connection. Currently, ASO is the conventional radical operation for transposition of the great arteries (TGA) and the Taussig-Bing anomaly (TBA) characterized by both the double-outlet right ventricle and the subpulmonic ventricular septal defect (VSD) [1]. Between January 2000 and December 2008, we performed 68 consecutive ASO in infants older than 1 month of age. A total of 45 infants had TGA plus VSD, and 23 infants had TBA. Thirty-eight infants were older than 6 months of age. Although these infants had missed the optimal surgery time window of up to 4 weeks after birth, and some exhibited additional moderate-to-severe pulmonary hypertension, the herein described ASO showed satisfying operative results.
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Material and Methods
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Patient Population
In this retrospective study, 68 infants from two Chinese hospitals were recruited between January 2000 and December 2008 to undergo ASO. A total of 45 infants had TGA plus VSD and 23 had TBA (Table 1). The mean patient age ± standard deviation was 15.9 ± 26.6 months (range, 1 month to 11 years), and the mean weight was 8.5 ± 6.3 kg (range, 4.6 to 22 kg). All patients or their families gave consent, and the patients were approved by the institutional review boards of the two hospitals for the study.
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Table 1 Frequency of Transposition of the Great Arteries Plus Ventricular Septal Defect and Taussig-Bing Anomaly in Different Age Groups
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A total of 30 infants were 1 to 6 months old (group A), and 38 children were older than 6 months of age (group B; Table 2). The median age was 2.89 months in group A and 19.77 months in group B.
Preoperative Clinical Data
Preoperative data measurement included body weight, mean transcutaneous arterial oxyhemoglobin saturation, hemoglobin content, pulmonary vascular resistance (PVR), and mean pulmonary artery pressure (PAP; Table 2). The preoperative diagnoses were confirmed by electrocardiography, chest roentgenography, or Doppler echocardiography. Selective preoperative angiocardiography and Swan-Ganz catheterization were each performed in 51 cases (75%). Pulmonary vascular resistance was calculated by formula from Swan-Ganz data. The differences in mean PAP and PVR between the two groups were statistically significant (p < 0.05; Table 2).
Relevant Anatomy
The relative anatomic position between the aorta and the pulmonary artery (PA) was anteroposterior in 26.5% (18 of 68 patients), right anterior and left anterior in 42.6% (29 of 68 patients), left posterior and right posterior in 22.1% (15 of 68 patients), and right-left juxtaposition in 8.8% (6 of 68 patients) of the children. According to the classification of the coronary artery of Yacoub and colleagues [1] (Fig 1), type A was present in 77.9% (53 of 68 patients), type B in 7.6% (5 of 68 patients), type C in 0% (0 of 68 patients), type D in 11.8% (8 of 68 patients), and type E in 2.9% (2 of 68 patients) of the patients.
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Fig 1. The five types of coronary artery anatomic positions between the aorta and the pulmonary artery as described by Yacoub and associates. (Reprinted from Dibardino DJ, Allison AE, Vaughn WK, McKenzie ED, Fraser CD Jr, Current expectation for newborns undergoing the arterial switch operation, Ann Thorac Surg; 239:588–98 [1], with permission.)
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Concomitant Cardiac Anomalies
The following additional cardiac conditions were present in the overall patient population: atrial septal defect in 28 patients (41.2%), patent ductus arteriosus in 40 patients (58.8%), left ventricular outflow tract stenosis (including subvalvular aortic stenosis) in 6 patients (8.8%), acleistocardia in 14 patients (20.6%), mild tricuspid stenosis in 1 patient (1.5%), mild tricuspid insufficiency in 1 patient (1.5%), mild-to-moderate valvular pulmonary stenosis in 2 patients (2.9%), and juxtaposed atrial appendage in 1 patient (1.5%). Of the 29 TGA plus VSD patients, 4 had multiple VSDs, 3 patients had subconal VSD, and 22 patients had perimembranous VSD.
Palliative Operation (Stage I)
Three patients (1 patient with TBA, 2 patients with TGA plus VSD) underwent PA banding operation plus systemic-pulmonary shunt operation.
Arterial Switch Operation Description
Arterial switch operation was performed under systemic anesthesia, using low-flow (ie, 50 mL · kg–1
· min–1) hypothermic (range, 18° to 22°C) cardiopulmonary bypass. In patients with TBA, Dacron patches were used to repair the VSD in the left ventricle. The mean cardiopulmonary bypass duration was 211.0 ± 56.5 minutes (range, 120 to 360 minutes), and the mean aortic cross-clamp time was 130.3 ± 44.7 minutes (range, 70 to 280 minutes). Bypass duration and aortic cross-clamp time were not significantly different between groups A and B (Table 3). Additional cardiac anomalies were treated during the same surgical session.
Postoperative Management
Arterial blood pressure and central venous pressure were continuously, invasively monitored on a routine basis, and transcutaneous blood oxygen saturation and surface electrocardiogram were measured. In all but 6 children the left atrial pressure was continuously monitored. Pulmonary arterial pressure was continuously monitored by using cardiac catheterization in infants with preoperative severe pulmonary hypertension. For sedation, all infants were continuously administered fentanyl, pipecuronium bromide, or positive inotropic drugs, such as intravenous injections of moderate-to-low doses of dopamine, nitroglycerin, or epinephrine on a routine basis.
Statistical Analysis
Statistical analyses were performed using the SPSS software, version 11.5 (SPSS, Inc, Chicago, IL). Data were expressed as mean ± standard deviation. The Student's t test was used to compare the mean values of groups A and B, with the probability values being statistically significant at the 0.05 level.
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Results
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The perioperative results are shown in Table 3. The overall average hospitalization time was 32.57 ± 22.54 days (range, 7 to 72 days), and the average intensive care unit duration was 16.15 ± 15.13 days (range, 4 to 83 days), with an average tracheal intubation duration of 198.38 ± 281.35 hours (range, 11 to 968 hours). The average postoperative intensive care unit and hospitalization durations were not significantly different between groups A and B (p > 0.05; Table 3). Mean PAP in group B decreased from 46.5 ± 16.3 mm Hg preoperatively to 23.3 ± 8.7 mm Hg (p < 0.05) postoperatively. Two patients of group B experienced severe (>800 dyne · s · cm–5) PVR increment, namely, 878.3 dyne · s · cm–5 and 1261.9 dyne · s · cm–5. Although postoperative recovery was difficult in these patients, with a required mechanical ventilation time as long as 61 or 75 hours, they eventually recovered and could be discharged from the hospital. In 6 patients, major postoperative complications occurred: 1 case of pericardial tamponade and open-chest drainage; 1 case of interventricular residual septal shunt; 2 cases of diagnosed atrioventricular transduction block (grade III) with required permanent pacemaker implantation; and 2 cases of tracheostomy as a result of chylothorax, lung infection, pneumothorax, and respiratory insufficiency.
Six patients of the overall population (8.8%) died after surgery. The mortality rate in group A was 10.0% (3 of 30 patients) and in group B, 7.9% (3 of 38 patients), with no significant difference between the two groups (p > 0.05; Table 3). Thus, the mortality rate was not higher in the older patients who were already beyond the optimal surgical time window for ASO. The causes of death in these 6 patients were as follows: severe low cardiac output, ventricular fibrillation owing to the PA suppressing the left coronary artery, chylothorax, systemic infection, unexplained sudden death, acute pulmonary edema, and grade III atrioventricular transduction block with required pacemaker implantation inducing serious arrhythmia and multiple organ failure. The three causes of death in group B were as follows: (1) postoperative extensive oozing of blood, low cardiac output, and renal failure; (2) postoperative chylothorax and acute pulmonary edema; and (3) ventricular fibrillation caused by the PA suppressing the left coronary artery owing to the surgical technique. These causes of deaths were independent from the preoperatively increased PAP or PVR.
One of the 62 surviving patients experienced sequelae of cerebral hypoxia, but the other surviving patients recovered and were discharged from the hospital. Follow-up examinations in these patients after a mean of 13.5 ± 7.9 months (range, 0.5 to 56 months) showed significantly improved cardiac function, resolution of cyanosis, increase of activity value, normal physique development without any long-term complications, and no cases of death during this period.
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Comment
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In 1975, Jatene and colleagues described for the first time a successful ASO for the treatment of TGA. Owing to further progress in cardiac surgery techniques and improvement of postoperative monitoring, ASO has gradually become extremely successful in the treatment of TGA in infants and is presently considered the best surgical method for this condition. Currently, the total operative mortality rate of ASO has stabilized at approximately 5% to 8% or even lower [2]. Transposition of the great arteries plus VSD is currently considered the main cause of pathologic changes in pulmonary vessels. Therefore, ASO is performed in newborn infants within 2 weeks after birth, if possible [3]. Foran and associates [2] showed, however, that the ASO outcome is also successful in newborns aged 3 weeks to 2 months with TGA plus VSD.
Arterial switch operation is also the method of choice for TBA with normal PA valve function. A patch is used to repair the VSD below the PA valve, to connect the anatomic right ventricle to the aorta, and to then switch the great arteries. Arterial switch operation has been demonstrated as an excellent therapeutic method for all arrangements of the great arteries in infants with TBA combined with or without the coarctation of the aorta in the early and middle stages [4].
In infants with TGA plus VSD or TBA, ASO should be performed as early as possible (preferably within 3 months, but no later than 6 months after birth) to avoid early and rapid development of pulmonary vascular obstructive disease [5, 6]. In China, however, infants with the described condition are often brought to the hospital only when they are older than 6 months of age, and thus beyond the optimal surgical window. In our study population, 38 children who had TGA plus VSD or TBA (in many cases combined with moderate-to-severe pulmonary hypertension) were older than 6 months. Mean PAP in this patient group was 46.5 ± 16.3 mm Hg (range, 24 to 80 mm Hg) and PVR was 489.7 ± 225.6 dyne · s · cm–5 (range, 74.1 to 1261.9 dyne · s · cm–5). Although PAP, PVR, and ventilation time were significantly higher than in the patients younger than 6 months of age, cardiopulmonary bypass time, aortic cross-clamp time, overall hospitalization duration, and intensive care unit duration were not significantly different between the two groups. In the older patient group, 2 patients had preoperative PVR of more than 800 dyne · s · cm–5. Clarkson and associates [6] showed that according to the Heath-Edwards grading system, 29% of the study patients aged 3 to 12 months with TGA plus VSD presented with grade III or greater pathologic changes of the pulmonary vessels versus 40% of the TGA plus VSD patients older than 12 months of age. It is generally considered as not appropriate to perform ASO in this older patient group. However, although the postoperative recovery of the above-mentioned 2 infants with high PVR was difficult, requiring mechanical ventilation times as long as 61 or 75 hours, PVR could be improved by strengthening postoperative management, application of 
-blockers, or persistent inhalation of low-flow nitric oxide. The patients eventually recovered and were discharged from the hospital after the following drug treatment: fentanyl and pipecuronium bromide were administered at an early stage for sedation, and concomitant vasoactive drugs such as mid-to-low doses of dopamine, nitroglycerin, and epinephrine were administered to maintain stable cardiopulmonary function. Mean PAP decreased from 46.5 ± 16.3 mm Hg preoperatively to 23.3 ± 8.7 mm Hg (p < 0.05) postoperatively. None of the three deaths in our group of older children was associated with increased PAP or PVR. The clinical outcome of these children has shown that ASO still leads to fairly good results if the children are in good general health, have no serious cyanosis, and have a rich blood supply to the lungs as shown in a chest roentgenograph, if cardiac catheterization shows that PVR is still within an acceptable range, and if perioperative management is improved.
The coronary artery transfer technology is a key factor for successful ASO. Distortion, compression, or stenosis of the transplanted coronary arteries is an important reason causing myocardial ischemia, acute cardiac dysfunction, and death after ASO. The six cases of death in our patient population are all related to the coronary vascular anastomotic technique leading to severe low cardiac output syndrome, serious arrhythmia, and ventricular fibrillation. Because of improvement of the transplantation techniques, these relevant complications have minimized coronary artery pattern-related risks [7]. Pulmonary stenosis is a major complication after ASO, requiring reoperation, which severely affects patient prognosis. Pulmonary stenosis was not found at follow-up in this group [8].
In summary, ASO procedures have been constantly improved in recent years. Arterial switch operation has become the surgery of first choice for the anatomic correction of complex congenital heart defects such as TGA or TBA, often combined with additional complex cardiac anomalies, such as large VSD, left-ventricular outflow tract stenosis, or coarctation of the aorta. Correction of these anomalies can be performed during the same ASO session performed for treatment of TGA or TBA, and the outcome shows satisfying medium-term curative effects also in children older than 6 months of age. However, the long-term outcome has still to be investigated.
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References
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- Dibardino DJ, Allison AE, Vaughn WK, McKenzie ED, Fraser Jr CD. Current expectation for newborns undergoing the arterial switch operation Ann Surg 2004;239:588-598.[Medline]
- Foran JP, Sullivan ID, Ellioff MJ, de Leval MR. Primary arterial switch operation for transposition of the great arteries with intact ventricular septum in infants older than 21 days J Am Coll Cardiol 1998;31:883-889.[Abstract/Free Full Text]
- Lupintti FW, Bove EL, Minich LL, et al. Intermediate-term survival and functional results after arterial repair for transposition of the great arteries J Thorac Cardiovasc Surg 1992;103:421-427.[Abstract]
- Mavroudis C, Backer CL, Muster AJ, Rocchini AP, Rees AH, Gevitz M. Taussig-Bing anomaly: arterial switch versus Kawashima intraventricular repair Ann Thorac Surg 1996;61:1330-1338.[Abstract/Free Full Text]
- Wetter J, Belli E, Sinzobahamvya N, Blaschzok HC, Brecher AM, Urban AE. Transposition of the great arteries associated with ventricular septal defect: surgical results and long term outcome Eur J Cardiothorac Surg 2001;20:816-823.[Abstract/Free Full Text]
- Clarkson PM, Neutze JM, Wardill JC, Barratt-Boyes BG. The pulmonary vascular bed in patients with complete transposition of the great arteries Circulation 1976;53:539-543.[Abstract/Free Full Text]
- Brown JW, Park HJ, Turrentine MW. Arterial switch operation: factors impacting survival in the current era Ann Thorac Surg 2001;71:1978-1984.[Abstract/Free Full Text]
- Prifti E, Crucean A, Bonacchi M, et al. Early and long term outcome of the arterial switch operation for transposition of the great arteries predictors and functional evaluation Eur J Cardiothorac Surg 2002;22:864-873.[Abstract/Free Full Text]
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Abstract
Introduction
