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Address for reprints: Takeshi Shinkawa, MD, PhD, Department of Cardiovascular Surgery, Heart Institute of Japan, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.
To assess long-term survival and reoperation-free survival after the arterial switch operation (ASO) and analyze the outcomes of reoperations after hospital discharge.
Methods
This was a single-institution retrospective study of 476 hospital survivors of ASO since August 1982. Preoperative diagnoses included 286 transpositions of the great arteries with intact septum, 143 transpositions with ventricular septal defect, and 47 double outlet right ventricles. There were 236 neonatal ASOs, 30 aortic arch repairs, 22 concomitant left ventricular outflow tract obstruction reliefs, 16 preoperative mild pulmonary regurgitations, and 13 intramural coronary arteries.
Results
During a median follow-up of 21.1 years (range, 0.1-39.2 years), 25 late deaths (5.3%) and 91 reoperations in 69 patients (14.5%) were noted. The reoperations included 44 left-sided reoperations in 34 patients (7.1%), 35 right-sided reoperations in 30 patients (6.3%), and 12 other reoperations in 12 patients (2.5%). Among the 69 patients who underwent reoperation, those with left-sided reoperations had lower survival at 15 years after reoperation compared to those with non–left-sided reoperations (91.2% vs 100%; P = .015; log-rank, 5.9). Multivariable analysis identified non-neonatal ASO, preoperative pulmonary regurgitation, intramural coronary artery, aortic arch repair, and concomitant left ventricular outflow tract obstruction relief as risk factors for left-sided reoperations. Reoperation-free survival was significantly higher in neonatal ASO compared with non-neonatal ASO (89.2% vs 75.2% at 20 years; P < .001; log-rank, 13.4).
Conclusions
Hospital survivors of neonatal ASO had favorable long-term outcomes.
Approximately 14% of patients who underwent an arterial switch operation (ASO) required reoperation after hospital discharge during a median follow-up of 21.1 years. Left-sided reoperations were associated with lower survival compared with non–left-sided reoperations. Neonatal ASO was associated with better overall reoperation-free survival.
Excellent survival of patients who undergo the arterial switch operation (ASO) has been reported.
However, hospital survivors may require reoperation for neo-aortic valve regurgitation (neo-AR), pulmonary artery (PA) stenosis, or coronary artery stenosis in the long term.
Long-term survival and freedom from coronary artery reintervention after arterial switch operation for transposition of the great arteries: a population-based Nationwide study.
This study assessed the long-term survival and reoperation-free survival after hospital discharge of patients who underwent ASO and analyzed the outcomes of reoperation after ASO.
Methods
Study Design
This retrospective study included consecutive patients who underwent ASO for transposition of the great arteries (TGA) or a TGA-type double-outlet right ventricle at the Tokyo Women’s Medical University Hospital between August 1982 and September 2021. Patients with ASO conversion from atrial switch, patients with single-ventricle physiology, and hospital deaths were excluded. This study was approved and monitored by the Tokyo Women’s Medical University Research Ethics Committee (approval no. 2022-0010; date of approval, May 16, 2022). Patient consent for the publication of their data was obtained for contactable patients, and the need for patient consent for uncontactable patients was waived owing to the retrospective nature of the study. Medical records were reviewed and basic demographic data, anatomic information, surgical history, intraoperative data, and postoperative outcomes were retrieved and analyzed.
since approximately 1990, our standard treatment for TGA with an intact ventricular septum has been neonatal ASO with the LeCompte maneuver during the study period, and PA banding prior to ASO was used only for patients with delayed presentation or contraindication for cardiopulmonary bypass. For a double outlet right ventricle with aortic arch obstruction, staged ASO following aortic arch repair with PA banding could be selected, depending on the case. For anticipated residual left ventricular outflow tract (LVOT) obstruction after ASO, concomitant relief of LVOT obstruction was performed if it could be done through the native pulmonary valve. In TGA with an intramural coronary artery, the aortopulmonary window technique (Imai technique) was preferred.
and more recent PA reconstructions were performed using an autologous pericardium patch for coronary button defects, considering the possibility of coronary ischemia caused by compression from the PA.
Indications and Technique for Reoperation
Neo-aortic valve surgery
Neo-aortic valve (AV) surgery was indicated for greater than moderate neo-AR with progressive left ventricular dilatation or dysfunction, and neo-aortic root replacement was indicated for neo-aortic root diameter >50 mm. For neo-AV surgery, AV replacement was performed for severely deformed leaflets or degenerative changes, and AV plasty with or without aortic root approximation was performed for slightly deformed leaflets with annular dilation. Bioprosthetic valves can be used in women of childbearing age. The Konno procedure was performed in patients with neo-AR with a small aortic annulus and supravalvular aortic stenosis or neo-AR with subaortic stenosis.
Subaortic stenosis resection or supravalvular aortic stenosis repair was indicated by a peak gradient of >40 mmHg at the LVOT or exacerbation of neo-AR caused by turbulence from subaortic stenosis. For subaortic stenosis, fibromuscular membranous tissue was resected through the neo-AV. For supravalvular aortic stenosis, reanastomosis after dividing the stenotic lesion or patch augmentation was performed in children and adolescents and artificial graft replacement was performed in adults.
Aortopulmonary window repair
Aortopulmonary window repair was indicated for patients with unstable hemodynamics owing to the aortopulmonary window following percutaneous transluminal angioplasty for PA stenosis. The aortopulmonary window was closed directly through the longitudinally incised main PA, and the PA was augmented with a patch.
Coronary artery operations
Coronary artery operations were indicated for coronary artery obstruction with myocardial ischemia. In coronary artery bypass grafting, the internal thoracic artery was used as a free graft from the ascending aorta to the left main trunk. In coronary angioplasty, the left main trunk of the coronary artery was augmented with an autologous pulmonary arterial wall.
Right ventricular outflow tract reconstruction/PA angioplasty
Intervention for right ventricular outflow tract (RVOT) obstruction or PA stenosis was indicated when the right ventricle–to–left ventricle systolic pressure ratio exceeded 60%.
For a small pulmonary valve annulus, RVOT reconstruction with a monocusp valved transannular patch was performed. For patients with a complex coronary artery anatomy, the expanded polytetrafluoroethylene valved conduit was bypassed from the anterior surface of the RVOT to the distal PA.
Statistical Analysis
Statistical analysis was performed using SPSS version 18.0 (SPSS). Continuous variables were expressed as mean ± SD or as median and range. The endpoint of follow-up was defined as the date of death or date of the last contact. In-hospital and late deaths were defined as deaths before and after hospital discharge, respectively. Actuarial survival rates and 95% CIs were analyzed using Kaplan–Meier methods, and comparisons between subgroups were performed using the log-rank test. All P values were 2-sided, and a P value <.05 was considered statistically significant.
Although 3 hospital survivors underwent a cardiac reoperation before hospital discharge (1 aortic valve replacement, 1 left ventricular pseudoaneurysm repair, and 1 coronary artery bypass grafting followed by mitral valve replacement), and 4 of 57 hospital nonsurvivors after ASO had a cardiac reoperation (1 ventricular septal defect reclosure, 1 tricuspid valve repair, 1 conversion to the Senning procedure, and 1 mitral valve replacement for mitral regurgitation) during the same admission, these reoperations were excluded from this study. LVOT obstruction was defined as stenosis at the LVOT caused by posterior deviation of the infundibular septum, accessory leaflet tissue of the atrioventricular valve, abnormal chordal attachments, or fibromuscular ridge. Clinically relevant symptoms of the obstruction were also considered. Aortic arch obstruction was defined as the presence of coarctation of the aorta, a hypoplastic aortic arch, or an interrupted aortic arch. Left-sided reoperation was defined as reoperation of the left ventricular system, coronary artery, or thoracic aorta, and right-sided reoperation was defined as reoperation of the right ventricular system or PA. The patients were also divided into 2 groups based on the operative year—1982 to 1994 (291 patients; 61.1%) and 1995 to 2021 (185 patients; 38.9%)—to analyze the effect of era. Differences in preoperative factors and operative outcomes between the groups were assessed using the χ2 test or t test. The Cox proportional hazards model was used to determine the risk factors for left-sided and right-sided reoperations using multivariable analysis. Each variable was found to be significantly associated with univariate analysis (P < .15) and was entered into the multivariable analysis (Video Abstract).
Results
A total of 476 hospital survivors were enrolled in the study. The median age at ASO was 1.0 months (range 0.1-99.4 months), and the cohort included 236 neonates (age <28 days). Preoperative diagnoses included 286 TGAs with intact septum, 143 transpositions with ventricular septal defects, and 47 double outlet right ventricles. Aortic arch obstruction and intramural coronary artery were found in 35 (7.4%) and 13 (2.7%) patients, respectively. Compared with neonatal ASO, non-neonatal ASO involved more complex anatomy, such as the presence of ventricular septal defect (53.3% vs 26.3%; P < .001), aortic arch obstruction (11.3% vs 2.5%; P = .001), and LVOT obstruction (9.6% vs 2.5%; P = .002). Previous PA banding was observed in 166 patients, more prevalent in non-neonatal ASO compared with neonatal ASO (68.8% vs 0.4%; P < .001). Mild preoperative pulmonary regurgitation was observed in 16 patients. Patient characteristics are summarized in Table 1.
Table 1Patient profiles at the arterial switch operation
Variables
Total
Neonate (N = 236)
Non-neonate (N = 240)
P value
Age at arterial switch operation, month, median (range)
Surgical methods for ASO included 464 LeCompte maneuvers (97.5%) and 12 Jatene procedures without switching artery positions (2.5%). The Pacifico method was used in 87 patients (18.2%). Nine patients (1.9%) underwent aortopulmonary window coronary transfer (Imai technique). Concomitant LVOT obstruction relief and neo-AV surgeries were performed in 22 and 5 patients, respectively. The details of the ASO technique are presented in Table 2.
Table 2Surgical details of the arterial switch operation
Variables
Total
Neonate (n = 236)
Non-neonate (n = 240)
P value
Surgical methods for arterial switch operation, n (%)
.26
LeCompte maneuver
464 (97.5)
228 (96.6)
236 (98.3)
Jatene procedure without switching the arterial positions
During a median follow-up of 21.1 years (range, 0.1-39.2 years), 25 late deaths (5.3%) and 91 reoperations in 69 patients (14.5%) were noted. Median patient survival at 10 years and 20 years after hospital discharge for ASO was 96.1% (range, 94.4%-97.9%) and 95.0% (range, 92.9%-97.0%), respectively (Figure 1, A), and reoperation-free survival at 10 years and 20 years after hospital discharge for ASO was 89.1% (range, 86.4%-92.2%) and 82.1% (range, 78.2%-85.9%), respectively (Figure 1, B).
Figure 1Kaplan–Meier curve of overall survival (A) and reoperation-free survival (B) after hospital discharge for an arterial switch operation.
Reoperations after hospital discharge included 44 left-sided reoperations with or without right-sided reoperations in 34 patients (7.1%), 35 isolated right-sided reoperations in 30 patients (6.3%), and 12 other patients (2.5%). Three patients underwent left- and right-sided reoperations at different times. The median age at first reoperation was 14.4 years (range, 2.0-32.8 years) for left-sided reoperations and 7.8 years (range, 0.9-21.7 years) for right-sided reoperations. More than 2 reoperations were required in 14 patients (20.3%), and 1 patient required 5 reoperations.
Nineteen of the 34 first left-sided reoperations were neo-AV surgeries (Figure 2). Twenty patients (58.8%) required concomitant RVOT reconstruction or PA angioplasty. The causes of 4 late deaths (11.8%) after left-sided reoperations were multiple organ failure at 3.2 years after the aortopulmonary window repair, infectious endocarditis and cerebral embolism at 12.1 years after the first neo-AV surgery, heart failure at 21.9 years after the first supravalvular aortic stenosis repair, and infectious endocarditis at 23.4 years after subaortic stenosis resection.
Among the 30 patients who underwent an isolated right-sided reoperation, all but 1 patient with tricuspid valve plasty underwent RVOT reconstruction or PA angioplasty (Figure 3). Preoperative cardiac catheterization showed a median peak pressure gradient of 70 mmHg (range, 36-140 mmHg), and the most common stenotic lesion was PA bifurcation in 11 patients (39.3%). All patients with only an isolated right-sided reoperation survived during a median follow-up of 26.5 years (range, 5.0-38.5 years), although 5 patients (16.7%) required a second reoperation. Twelve patients (2.6%) underwent other reoperations, including 10 pacemaker implantations for sick sinus syndrome or atrioventricular block and 2 cardioverter defibrillator device implantations with 1 cardiac resynchronization therapy.
Figure 3Clinical course after right-sided reoperation. RVOT, Right ventricular outflow tract; PA, pulmonary artery.
Among 69 patients who underwent reoperation, those with a left-sided reoperation had lower survival at 20 years after the reoperation compared to those with only a non–left-sided reoperation (91.2% vs 100%; P = .015; log-rank, 5.9) (Figure 4, A). Moreover, left-sided reoperations were associated with lower second reoperation-free survival at 20 years after the reoperation compared with non–left-sided reoperations (55.3% vs 91.5%; P = .018; log-rank, 5.6) (Figure 4, B).
Figure 4Kaplan–Meier curve of overall survival (A) and second reoperation-free survival (B) after reoperation.
Multivariable analysis for right-sided reoperations identified the Pacifico method as a protective factor for right-sided reoperation (P = .045; HR, 0.1; 95% CI, 0.02-1.0) and an intramural coronary artery (P = .004; HR, 5.7; 95% CI, 1.7-18.9) as a risk factor for right-sided reoperation (Table 3).
Late Coronary Artery Occlusion/Stenosis
Coronary artery occlusion or stenosis was found in 10 patients (2.1%) and 6 patients (1.3%), respectively, and their anatomy in Shaher classification was type 1 in 8 patients, type 2 in 5, type 4 in 2, and type 5 in 1. One patient with Shaher type 5 had an intramural coronary artery. The stenotic lesions were the left main trunk in 6 patients, right coronary artery in 5, left anterior descending coronary artery in 3, and left circumflex coronary artery in 3. One patient had 2 stenotic lesions.
Four patients (25%) underwent percutaneous coronary artery intervention at a median of 8.6 years (range, 5.0-28.7 years) after ASO, and 2 patients (12.5%) underwent coronary artery operations at 5.0 and 8.6 years after ASO. There were 3 deaths (18.8%) without coronary artery intervention; causes of death were acute coronary syndrome at 0.3 and 0.5 years after ASO in 2 patients and hemodynamic collapse at 10.8 years after ASO in 1 patient.
Era Effects
The patients who underwent ASO before 1995 underwent more previous PA banding than those who did so after 1995 (44.7% vs 19.5%; P < .001), and the rate of neonatal ASO was higher in patients after 1995 compared with in those before 1995 (70.8% vs 36.1%; P < .001). Patients with ASO before 1995 had more left-sided reoperations than those with ASO after 1995 (10.6% vs 3.4%; HR, 6.94; P = .01), and ASOs after 1995 was associated with significantly higher reoperation-free survival compared with ASOs before 1995 (90.4% vs 77.5% at 20 years; P = .003; log-rank, 8.9).
Neonatal ASO
Only 6 of 236 patients (2.5%) with neonatal ASO required left-sided reoperation, while 28 of 240 patients (11.7%) with non-neonatal ASO required left-sided reoperation (HR, 14.9; P < .001). There was no significant difference in patient survival between neonatal ASO and non-neonatal ASO (96.8% vs 93.2% at 20 years; P = .10; log-rank, 2.7) (Figure 5, A); however, patients with neonatal ASO had significantly higher reoperation-free survival compared to those with non-neonatal ASO (89.2% vs 75.2% at 20 years; P < .001; log-rank, 13.4) (Figure 5, B).
Figure 5Kaplan–Meier curve of overall survival (A) and reoperation-free-survival (B) after hospital discharge for a neonatal or non-neonatal arterial switch operation.
Figure 5Kaplan–Meier curve of overall survival (A) and reoperation-free-survival (B) after hospital discharge for a neonatal or non-neonatal arterial switch operation.
In the present study, 14.5% of the ASO survivors underwent reoperation after hospital discharge during a median follow-up of 21 years, and approximately one-fourth of the patients with reoperation required more than 2 reoperations. The incidence of reoperation after ASO was comparable to that in previous reports, and the number of left-sided and right-sided reoperations was almost equivalent.
Regarding left-sided reoperations, a European multicenter study reported a 90% of 15-year survival after left-sided reoperations, except for mitral valve operations.
European Congenital Heart Surgeons Association (ECHSA) study group. Left-sided reoperations after arterial switch operation: a European multicenter study.
Our study showed no hospital mortality and a similar 20-year survival after left-sided reoperations (91.2%). However, these patients tended to require multiple reoperations, and the second reoperation-free survival rate after left-sided reoperation was only 55.3% at 20 years. Repeated reoperations seemed to have acceptable early mortality (1 early death among 7 repeated reoperations), but had 2 late deaths, caused by cardiac dysfunction and PA occlusion. Preoperative pulmonary regurgitation and concomitant LVOT obstruction relief were associated with the risk of neo-AR, and aortic valve replacement was the most frequently selected surgical technique for neo-AV surgery after ASO.
In our cohort, 4 patients underwent aortopulmonary window repair following percutaneous transluminal angioplasty, with 1 late mortality, and the risk of a possible aortopulmonary window should be recognized in cases of PA stent implantation or stent redilation.
and 1 of our patients with supravalvular aortic stenosis repair required a total of 3 reoperations. Coronary artery stenosis or occlusion was found in 3.4% of our patients with ASO, an incidence close to that in a previous report.
Among our 16 patients with postoperative coronary artery stenosis or occlusion, 3 patients without coronary artery intervention died from myocardial ischemia at 0.3, 0.4, and 10.8 years after ASO, and 1 of 2 patients with a coronary artery operation experienced mitral regurgitation after hospital discharge. Because myocardial ischemia due to coronary artery compression or distortion can occur many years after ASO, we believe that regular postoperative coronary artery evaluation should be considered even without ischemic symptoms. There is no clear consensus regarding the modality of coronary evaluation and its frequency after ASO; however, we believe that angiography for infants and coronary computed tomography scan for older children can provide sufficient resolution for anatomic evaluation and can be performed at each growth spurt.
Regarding right-sided reoperations, the Pacifico method was a protective factor for right-sided reoperations, and only 1 of 87 hospital survivors who underwent the Pacifico method required a right-sided reoperation. However, 4 patients (4.6%) who underwent the Pacifico method sustained coronary artery stenosis, and no significant difference was noted in the incidence of postoperative coronary artery stenosis between patients with and those without the Pacifico method (4.6% vs 3.2; χ2 = 0.50; P = .51). Hoashi and colleagues
commented that direct anastomosis by the only native vessels at the PA reconstruction promoted PA growth, and the Pacifico method might be indicated for patients who are less likely to develop coronary artery compression. However, we prefer autologous pericardium patch augmentation for PA reconstruction as a standard technique, and the longitudinal extension technique at the ASO might be a good alternative to prevent overstretching of the pulmonary bifurcation and to avoid coronary artery compression by the PA branch.
Furthermore, in this study, the intramural coronary artery was associated with right-sided reoperation, despite the Imai technique being effective in transferring the intramural coronary artery or inseparable coronary arteries with an almost single orifice.
Regarding the era effect, approximately one-half of ASOs performed before 1995 involved previous PA banding, and ASOs performed before 1995 were associated with a higher rate of left-sided reoperations and lower reoperation-free survival compared with ASOs performed after 1995. However, the rate of neonatal ASO has been increasing since mid-1990s, and the Cox proportional hazard model showed that ASO before 1995 was not a risk factor for either left-sided or right-sided reoperations.
Regarding the timing of ASO, among 236 neonatal ASO hospital survivors, the 10- and 20-year reoperation-free survival rates were 92.6% and 89.2%, respectively. In 2008, we evaluated the late outcomes of ASO hospital survivors followed up for more than 15 years and found significant differences in survival rate and reoperation-free survival after ASO between primary and secondary ASOs.
However, with longer follow-up than in the previous study, more patients in our present cohort required a reoperation after the ASO. For this reason, the reoperation-free survival in neonatal ASO (mostly primary ASO) was higher than that in non-neonatal ASO (approximately 70% of patients, secondary ASO) in this study. Furthermore, non-neonatal ASO was identified as a risk factor for left-sided reoperation. Hospital survivors of neonatal ASO had more favorable outcomes.
The limitations of this study include its retrospective nature. A prospective multicenter cohort study with detailed data collection on imaging, operative techniques, and follow-up is needed to evaluate surgical risk factors in more detail.
In conclusion, approximately 7% of ASO hospital survivors required left-sided reoperation. Patients who underwent left-sided reoperations had worse prognoses than those who underwent only non–left-sided reoperations. Hospital survivors of neonatal ASO had significantly better overall reoperation-free survival.
Conflict of Interest Statement
The authors reported no conflicts of interest.
The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest.
Long-term survival and freedom from coronary artery reintervention after arterial switch operation for transposition of the great arteries: a population-based Nationwide study.
European Congenital Heart Surgeons Association (ECHSA) study group. Left-sided reoperations after arterial switch operation: a European multicenter study.
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