Outcomes of the Arterial Switch Operation for Transposition of the Great Arteries: 25 Years of Experience

Outcomes of neo-aortic valve and root surgery late after arterial switch operation

BACKGROUND

Neo-aortic root dilatation and valve regurgitation are emerging problems late after arterial switch operation (ASO). We sought to evaluate the prevalence and outcomes of neo-aortic root or valve reoperation after ASO.

METHODS

All patients with biventricular circulation who underwent an ASO between 1983 and 2015 were included at a single institution.

RESULTS

In our cohort of 782 late ASO survivors, the median duration of follow-up was 18.1 years (interquartile range [IQR], 11.3-25.6 years). During follow-up, 47 patients (6.0%) underwent 60 reoperations on the neo-aortic valve/root. The first neo-aortic valve/root reoperation occurred at a median of 15.2 years (IQR, 7.8-18.4 years) after ASO. Operations included mechanical Bentall (31.9%; n = 15), aortic valve repair (25.5%; n = 12), mechanical aortic valve replacement (AVR) (21.3%; n = 10), valve-sparing root replacement (19.1%; n = 9), and the Ross procedure (2.1%; n = 1). There was 1 late death (2.1%). Multivariable predictors of neo-aortic valve/root reoperation were bicuspid valve (hazard ratio [HR], 4.8; 95% confidence interval [CI], 2.1-10.7; P < .001), Taussig-Bing anomaly (HR, 3.0; 95% CI, 1.2-7.4; P < .02), previous pulmonary artery band (HR, 2.8; 95% CI, 1.2-6.3; P < .01) and left ventricular outflow tract obstruction before ASO (HR, 2.4; 95% CI, 1.0-5.8; P < .04). Freedom from neo-aortic valve or root reoperation was 98.0% (95% CI, 96.7%-98.8%) at 10 years, 93.3% (95% CI, 90.8%-95.2%) at 20 years, and 88.5% (95% CI, 84.1%-91.8%) at 30 years after ASO. Among the 47 patients who underwent neo-aortic reoperation, freedom from AVR was 82.3% (95% CI, 67.7%-90.7%) at 10 years, 58.0% (95% CI, 41.8%-71.2%) at 20 years, and 43.2% (95% CI, 27.0%-58.3%) at 25 years after ASO.

CONCLUSIONS

The need for neo-aortic valve or root reoperation surpasses 10% by 30 years post-ASO. Evolving understanding of the mechanisms of neo-aortic valve insufficiency and techniques of neo-aortic valve repair may decrease the need for AVR.

Cardiac Catheterization Interventions in the Right Ventricular Outflow Tract and Branch Pulmonary Arteries Following the Arterial Switch Operation

The arterial switch operation for d-transposition of the great arteries achieves anatomic repair but creates the potential for right ventricular outflow tract obstruction as a result of the LeCompte maneuver. The resultant right ventricular hypertension is generally well tolerated but a select group are referred for cardiac catheterization. The outcomes of these catheterizations have not been well described. The objective of this study was to describe the degree and nature of right ventricular outflow tract obstruction found during cardiac catheterization among patients following the arterial switch operation as well as determine the rate of intervention and assess the acute impact of any catheter intervention undertaken. We conducted a retrospective study of patients after arterial switch operation with the LeCompte maneuver and subsequent right heart catheterization. Descriptive statistics were reported, and paired sample t tests were used for analysis. 544 children had an arterial switch operation, of which 110 children (20%) had a cardiac catheterization procedure after surgery and 11% had a right heart catheterization. Of the right heart catheterizations, 90% had an intervention (balloon and/or stent). In the interventional group, the right ventricle to systemic pressure ratio decreased modestly, from 2/3 to half systemic, after balloon dilation and/or stent placement (p < 0.01). No serious complications were observed.

Potential benefits of prenatal diagnosis of TGA in Australia may be outweighed by the adverse effects of earlier delivery: likely causation and potential solutions

OBJECTIVE

Prenatal diagnosis of transposition of great arteries (TGA) is expected to improve postoperative outcomes after neonatal arterial switch operation (ASO); however, published reports give conflicting results. We aimed to determine the association between prenatal diagnosis and early postoperative outcomes after neonatal ASO.

METHODS

Cohort study involving 243 newborns who underwent ASO (70% prenatally diagnosed) between 2010 and 2019. Multivariable regression was used to determine the association between prenatal diagnosis and (a) birth characteristics and (b) postoperative outcomes.

RESULTS

Gestational age and birthweight centile were lower and small-for-gestational-age more common (11.8% vs 1.4%) in those diagnosed prenatally. Among births which followed labour induction or prelabour caesarean, prenatal diagnosis was associated with earlier gestation at birth (mean (SD), 38.5 (1.6) vs 39.2 (1.4), p=0.01). Among births which followed spontaneous labour, prenatal diagnosis was associated with earlier gestation at labour onset (38.2 (1.8) vs 39.2 (1.4), p=0.01). Prenatal diagnosis was associated with longer postoperative mechanical ventilation (incidence rate ratio 1.74, 95% CI 1.37 to 2.21), intensive care (1.70, 1.31 to 2.21) and hospital length of stay (1.37, 1.14 to 1.66) after ASO. Gestational age mediated up to 60% of the effect of prenatal diagnosis on postoperative outcomes.

CONCLUSION

Among newborns undergoing ASO for TGA, prenatal diagnosis is associated with poorer early postoperative outcomes. In addition to minimising iatrogenic factors (such as planned births) resulting in earlier births, evaluation of other dynamics following a prenatal diagnosis which may result in poor fetal growth and earlier onset of spontaneous labour is important.

Outcomes of the Arterial Switch Operation in Patients With Dextrocardia

BACKGROUND

Patients with dextrocardia and d-transposition of the great arteries (d-TGA) present a technical challenge when performing the arterial switch operation (ASO). We sought to determine the long-term outcomes of this rare presentation.

METHODS

All patients who underwent the ASO with d-TGA and dextrocardia were identified from the hospital database.

RESULTS

There were four patients with dextrocardia (4 of 844, 0.5%) patients; two patients had situs solitus and two patients had situs inversus. Three patients had a ventricular septal defect. Left ventricular outflow tract obstruction was present in one patient and one patient had a hypoplastic arch with severe coarctation of aorta. Anomalous coronary anatomy occurred in two patients. There was one early mortality and the cause of death was sepsis. One patient required late reoperation for severe neo-pulmonary valve regurgitation at 23 years after the ASO. At last follow-up, all three surviving patients were in New York Heart Association Class I.

CONCLUSIONS

Patients with d-TGA and dextrocardia who undergo the ASO are extremely rare and require challenging operative management.

Aortic root rotational position associates with aortic valvar incompetence and aortic dilation after arterial switch operation for transposition of the great arteries

PURPOSE

Aortic dilation and valvar regurgitation can develop in transposition of the great arteries (TGA) after the arterial switch operation (ASO). Variation in aortic root rotational position affects flow dynamics in patients without congenital heart disease. The aim of this study was to assess neo-aortic root (neo-AoR) rotational position and its association with neo-AoR dilation, ascending aorta (AAo) dilation, and neo-aortic valvar regurgitation in TGA following ASO.

METHODS

Patients with TGA repaired by ASO who underwent cardiac magnetic resonance (CMR) were reviewed. Neo-AoR rotational angle, neo-AoR and AAo dimensions indexed (to height), indexed left ventricular end diastolic volume (LVEDVI), and neo-aortic valvar regurgitant fraction (RF) were obtained from CMR.

RESULTS

Among 36 patients, the median age at CMR was 17.1 years (12.3, 21.9). Neo-AoR rotational angle (range - 52 to + 78°) was clockwise ( ≥ + 15°) in 50%, counterclockwise (<-9°) in 25%, and central (-9 to + 14°) in 25% of patients. A quadratic term for neo-AoR rotational angle, indicating increasing extremes of counterclockwise and clockwise angles, was associated with neo-AoR dilation (R² = 0.132, p = 0.03), AAo dilation (R² = 0.160, p = 0.016), and LVEDVI (R² = 0.20, p = 0.007). These associations remained statistically significant on multivariable analyses. Rotational angle was negatively associated with neo-aortic valvar RF on univariable (p < 0.05) and multivariable analyses (p < 0.02). Rotational angle was associated with smaller bilateral branch pulmonary arteries (p = 0.02).

CONCLUSION

In patients with TGA after ASO, neo-AoR rotational position likely affects valvar function and hemodynamics, leading to a risk of neo-AoR and AAo dilation, aortic valvar incompetence, increasing left ventricular size, and smaller branch pulmonary arteries.

The management of newborns with critical congenital heart diseases prior to transport to a cardiac center

Critical congenital heart diseases (CCHD) are important causes of mortality and morbidity in the newborn period. Even after diagnosis, their management could be seriously compromised by the unplanned delivery in hospitals with limited expertise and resources. The newborn may spend days or week before transport putting a significant burden on the neonatal team to manage such challenging diseases. In this review, the management principles of each individual pathology are discussed in the setting before transport to cardiac centers. Understanding these principles will help the treating teams evaluate and manage those complex conditions. The review avoids the advanced discussion on the management of CCHDs not applicable to the pre-transport setup. It highlights the critical elements in the maintenance of normal hemodynamics specific to each pathology and their variation.

Comprehensive outcomes after primary arterial switch operation

OBJECTIVE

To report the long-term outcomes of the arterial switch operation for transposition of the great arteries.

METHODS

The data of 35 patients who underwent an arterial switch operation between April 2006 and May 2021 were retrospectively examined; five had double-outlet right ventricles, three had side-by-side transposition, and 27 had d-transposition. The punch-out technique was the basic method for coronary transplantation; however, if coronary artery kinking after additional peeling was a concern, the trap-door technique was used. In aortic reconstruction, the caliber difference between the neoascending aorta and the native pulmonary artery was fixed using the pulmonary artery flap. In pulmonary reconstruction, the pulmonary artery was bilaterally exposed over the second branch.

RESULTS

The median age at operation and follow-up duration were 10.0 (8.0-12.5) days and 72.9 (40.7-139.5) months, respectively. Thirty-four patients survived, and one was lost to follow-up ([coronary transplantation]: right coronary artery, punch-out = 31, trap-door = 2; left coronary artery, punch-out = 28, trap-door = 7; [aortic regurgitation]: no-slight = 27, mild = 6, moderate = 1; [pulmonary regurgitation]: no-slight = 22, mild = 11, moderate = 1). Slight coronary bending occurred in two patients; ischemia was not observed. Catheter stent placement was performed in one of three patients with stenosis at the pulmonary artery bifurcation. Catheter balloon dilation was performed in one patient with supravalvular pulmonary stenosis. There were no cases of coronary, aortic, or pulmonary artery reoperations. The 15-year cumulative reintervention avoidance rate was 91.0%.

CONCLUSIONS

There were no deaths or reoperations during the long-term follow-up period, and arterial switch operation outcomes at our hospital were satisfactory.

Quantification of Pulmonary Artery Configuration after the Arterial Switch Operation: A Pilot Study

Background: The arterial switch operation (ASO) is the preferred treatment for d-transposition of the great arteries (TGA). Freedom from reintervention is mainly determined by the performance of the arterial outflow tracts, with variable incidence of pulmonary artery stenosis (PAS), possibly related to aspects of surgical technique. This pilot study attempts to describe pulmonary artery (PA) configuration through several measurements using three-dimensional data from cardiac magnetic resonance (CMR) imaging and assesses whether PA configuration is associated with PAS. Methods: A retrospective, single-centre analysis of paediatric patients undergoing CMR after ASO. The geometry of the pulmonary arteries was compared between patients with and without PAS as judged by the CMR report. Results: Among all patients (n = 612) after ASO, 45 patients underwent CMR at a median age of 10 years (3.5–13). Twenty-two (57.9%) had PAS, categorized as mild (n = 1), moderate (n = 19) or severe (n = 2). Eighteen had stenosis on PA branches. Four had MPA stenosis. Comparison between groups with and without PAS revealed no significant differences in neo-aortic to pulmonary angle, MPA to LPA/RPA angle, or bifurcation angle. There was a significant difference in cranial displacement, with more cranial displacement in the group without PAS. However, this group was older, 10.8 (7.3–14.3) years compared to those with PAS, 6.8 (1.5–12.1). Conclusions: The spectrum of PAS after ASO is heterogenous. This study shows the feasibility of measuring PA configuration in three planes on CMR. There is no correlation between PA configuration and PAS. Therefore, other mechanisms are probably responsible for the occurrence of PAS, rather than the configuration on itself. Further multicentric studies are warranted to confirm the suggested measuring method and assessing the associations with PAS, to eventually advise surgical methodology.

Impact of Coronary Artery Anatomy in Arterial Switch Operation: In-hospital and Post-discharge Outcomes

OBJECTIVE

The influence of the coronary artery anatomy on the prognosis of patients receiving an arterial switch operation (ASO) is currently controversial, and the risk factors for this operation may change in more complicated patients. This study aimed to investigate the influence of coronary artery anomalies on the in-hospital and post-discharge outcomes of ASO in patients with transposition of the great arteries (TGA) and Taussig-Bing anomaly (TBA).

METHODS

We retrospectively reviewed 206 patients who underwent ASO from January 2007 to December 2019. The median age at operation was 33 [interquartile range (IQR): 20-71] days. Median follow-up time was 7.2 years (IQR: 4.0-10.3 years).

RESULTS

Coronary anomalies were present in 86 patients (41.7%), with 9 (4.4%) of them having a single coronary artery. Additional coronary features included intramural courses in 5 (2.4%) patients, ostial stenosis in 1 (0.5%) patient, and accessory coronary artery orifices in 5 (2.4%) patients. There were 32 (15.5%) in-hospital deaths and 8 (4.6%) post-discharge deaths, yielding an overall survival of 81.3%, 80.7% and 79.9% at 1, 5 and 10 years, respectively. Mortality due to ASO has been drastically decreased since 2013. Patients with a single coronary artery had higher rate of in-hospital mortality, but this finding was not statistically significant. The earlier surgical era (OR: 2.756) and a longer cardiopulmonary bypass time (OR: 2.336) were significantly associated with in-hospital mortality, while coronary patterns were not. An intramural coronary artery (HR: 10.034) and a patient age of older than 1 year at the time of ASO (HR: 9.706) were independent predictors of post-discharge mortality.

CONCLUSION

ASO remains the procedure of choice for TGA with coronary anomalies with acceptable in-hospital and post-discharge outcomes in terms of overall survival and freedom of reoperation. However, intramural coronary artery is an independent risk factor for post-discharge mortality. Timely surgery within the 1st year of life helps improve overall midterm survival of ASO.

Early Outcomes of Patients Undergoing Neoaortic Valve Repair Incorporating Geometric Ring Annuloplasty

OBJECTIVES

During congenital heart surgery, the pulmonary valve and root may be placed into the systemic position, yielding a "neoaortic" valve. With the stress of systemic pressure, the pulmonary roots can dilate, creating aneurysms and/or neoaortic insufficiency (neoAI). This report analyzes the early outcomes of patients undergoing neoaortic valve repair incorporating geometric ring annuloplasty.

METHODS

Twenty-one patients underwent intended repair at six centers and formed the study cohort. Thirteen had previous Ross procedures, five had arterial switch operations, and three Fontan physiology. Average age was 21.7 ± 12.8 years (mean  ±  SD), 80% were male, and 11 (55%) had symptomatic heart failure. Preoperative neoAI Grade was 3.1  ±  1.1, and annular diameter was 30.7  ±  6.5 mm.

RESULTS

Valve repair was accomplished in 20/21, using geometric annuloplasty rings and leaflet plication (n = 13) and/or nodular release (n = 7). Fourteen had neoaortic aneurysm replacement (13 with root remodeling). Two underwent bicuspid valve repair. Six had pulmonary conduit changes, one insertion of an artificial Nodulus Arantius, and one resection of a subaortic membrane. Ring size averaged 21.9  ±  2.3 mm, and aortic clamp time was 171  ±  54 minutes. No operative mortality or major morbidity occurred, and postoperative hospitalization was 4.3  ±  1.4 days. At discharge, neoAI grade was 0.2  ±  0.4 (P < .0001), and valve mean gradient was ≤20 mm Hg. At average 18.0  ±  9.1 months of follow-up, all patients were asymptomatic with stable valve function.

CONCLUSIONS

Neoaortic aneurysms and neoAI are occasionally seen late following Ross, arterial switch, or Fontan procedures. Neoaortic valve repair using geometric ring annuloplasty, leaflet reconstruction, and root remodeling provides a patient-specific approach with favorable early outcomes.

Post-operative Chylothorax in Patients with Repaired Transposition of the Great Arteries

Patients with dextro-transposition of the great arteries (d-TGA) require surgical repair as neonates. These patients are at risk for post-operative chylothorax. We sought to describe the presentation, imaging, and outcomes after intervention for patients with d-TGA with post-operative chylothorax. A retrospective chart review was performed in patients with repaired d-TGA who were referred from 1/1/2013 to 4/1/2020 for evaluation of chylothorax. Patient history, lymphatic imaging, and interventional data were collected. Impact of intervention on lymphatic drainage was evaluated with a student's t-test. Eight patients met inclusion criteria for this study. Five patients had a history of central venous thrombus leading to thoracic duct outlet occlusion. Five patients underwent intervention, two were managed conservatively, and one was not a candidate for intervention. Chylothorax resolved in six patients. There was a significant difference in output from 7 days prior to first intervention (114 mL/kg/day) compared to 28 days following final intervention (27 mL/kg/day, p = 0.034). There were no procedural complications. Chylothorax in patients with repaired transposition of the great arteries is often amenable to intervention. Early surveillance and management of central venous thrombosis may reduce the burden of lymphatic disease in these patients.

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.

Louis J, Raghuveer G, Kochilas L. Outcomes Following Aortic Valve Replacement in Children With Conotruncal Anomalies

OBJECTIVE

Conotruncal anomalies can develop aortopathy and/or aortic valve (AV) disease and AV replacement (AVR) is occasionally needed. We report long-term results and examine factors affecting survival following AVR in this group.

METHODS

We queried the Pediatric Cardiac Care Consortium (PCCC, US database for interventions for congenital heart diseases) to identify patients with repaired conotruncal anomalies and AVR. Long-term outcomes were provided by the PCCC, the US National Death Index, and Organ Procurement and Transplantation Network. Competing risks analysis examined outcomes following AVR (death/transplantation, reoperation) and multivariable regression analysis assessed significant factors.

RESULTS

One hundred six children with repaired conotruncal anomalies underwent AVR (1982-2003). Underlying anomaly was truncus (n = 40), d-transposition (n = 22), type-B interrupted arch (n = 16), double-outlet right ventricle (n = 12), pulmonary atresia with ventricular septal defect (n = 9), tetralogy of Fallot (n = 6), corrected transposition (n = 1). 18 (17%) had prior aortic valvuloplasty (surgical = 12, percutaneous = 6). Median age at AVR was 6.9 years (interquartile range = 2.5-12.4). AV pathophysiology was regurgitation (n = 83, 78%), stenosis (n = 9, 9%), and mixed (n = 14, 15%). AVR type was mechanical (n = 72, 68%), homograft (n = 21, 20%), and Ross (n = 13, 12%). Operative mortality was 13(12%). Infant age at AVR was risk factor (odds ratio = 55, 95% confidence interval [CI] = 6-539, P = .0006). On competing risks analysis, five years after AVR, 6% died or received transplantation, 20% had reoperation. Twenty-five years transplant-free survival was 53%. Factors associated with death after hospital discharge included mitral surgery (hazards ratio [HR] = 11, 95% CI = 3-39, P = .0002), underlying defect (HR = 2, 95% CI = 1-5, P = .446). Twenty years transplant-free survival in conotruncal anomalies group was inferior to matched children undergoing AVR for congenital non-conotruncal disease (61% vs 82%, P = .0012).

CONCLUSIONS

Long-term survival following AVR in children with conotruncal anomalies is inferior to that of isolated congenital AV disease and is linked to an underlying cardiac defect. Although valve type was not associated with survival, infant age was a risk factor for operative mortality. Continuous attrition and high reoperation warrant vigilant monitoring.

Coronary Artery Augmentation with the Right Subclavian Artery for Single Coronary Artery Variants of Dextro Transposition of the Great Arteries Treated by an Arterial Switch Operation

Objective

Single coronary artery variants in dextro transposition of the great arteries increase the technical demands of performing coronary translocations during the arterial switch operation (ASO). Coronary augmentation using the right subclavian artery as an interposition graft is a viable option in certain cases. The aim of this study is to describe this operative technique and review outcomes.

Methods

Of 59 patients who underwent an ASO, from July 2015 to May 2021, 6 had single coronary variants in which the right subclavian artery was used as an interposition graft. Mean follow-up was 21.5 months.

Results

Patients mean age and weight at the time of surgery were 7.1 ± 3.8 days and 2.84 ± 0.76 kg, respectively. Four patients had the left anterior descending coronary artery and right coronary artery coming from the left sinus and the circumflex coronary artery coming from the right sinus. One patient had a single ostium arising from the left sinus and another patient had a single ostium coming from the right sinus. All patients are alive and free of cardiac symptoms at follow-up.

Conclusions

Single coronary artery variants in dextro transposition of the great arteries can pose technical challenges for coronary translocation during ASO. The augmentation of coronary buttons using a segment of the right subclavian artery is an option which should be considered in selective cases.

The Impact of Prematurity on Morbidity and Mortality in Newborns with Dextro-transposition of the Great Arteries

Prematurity is a risk factor for adverse outcomes after arterial switch operation in newborns with D-TGA (D-TGA). In this study, we sought to investigate the impact of prematurity on postnatal and perioperative clinical management, morbidity, and mortality during hospitalization in neonates with simple and complex D-TGA who received arterial switch operation (ASO). Monocentric retrospective analysis of 100 newborns with D-TGA. Thirteen infants (13.0%) were born premature. Preterm infants required significantly more frequent mechanical ventilation in the delivery room (69.2% vs. 34.5%, p = 0.030) and during the preoperative course (76.9% vs. 37.9%, p = 0.014). Need for inotropic support (30.8% vs. 8.0%, p = 0.035) and red blood cell transfusions (46.2% vs. 10.3%, p = 0.004) was likewise increased. Preoperative mortality (23.1% vs 0.0%, p = 0.002) was significantly increased in preterm infants, with necrotizing enterocolitis as cause of death in two of three infants. In contrast, mortality during and after surgery did not differ significantly between the two groups. Cardiopulmonary bypass times were similar in both groups (median 275 vs. 263 min, p = 0.322). After ASO, arterial lactate (34.5 vs. 21.5 mg/dL, p = 0.007), duration of mechanical ventilation (median 175 vs. 106 h, p = 0.038), and venous thrombosis (40.0% vs. 4.7%, p = 0.004) were increased in preterm, as compared to term infants. Gestational age (adjusted unit odds ratio 0.383, 95% confidence interval 0.179-0.821, p = 0.014) was independently associated with mortality. Prematurity is associated with increased perioperative morbidity and increased preoperative mortality in D-TGA patients.

Mortality analysis of arterial switch operation for transposition of the great arteries with and without ventricular septal defect

OBJECTIVES

We aimed to evaluate the 90-day mortality and effect of rescue or urgent coronary revascularization in children undergoing arterial switch operation for transposition of the great arteries with and without ventricular septal defect.

METHODS

The 90-day mortality, risk factors for mortality and outcome of rescue or urgent coronary revascularization were analysed using 8 years of data from the Japan Cardiovascular Surgical Database. We only included patients with full data for all analyses.

RESULTS

A total of 1084 patients (median weight: 3.0 kg; interquartile range: 2.8-3.3) underwent arterial switch operation at a median age of 10 days (interquartile range: 7-14). The 90-day mortality (5.2%, n = 56) was ∼1.6-fold higher than 30-day mortality (3.2%, n = 35). The cause was cardiac origin in 84% of non-survivors. Fifty-nine of the 1034 patients (5.7%) required extracorporeal membrane oxygenation (ECMO), with successful weaning in 44% (n = 26). Univariable or multivariable analyses revealed the following risk factors for mortality: body weight at operation <2.5 kg, aortic cross-clamp time, cardiac events and ECMO (P < 0.005-0.001). Ventricular septal defect was not a risk factor.Thirteen patients (1.2%) had either rescue or urgent coronary revascularization with salvage rates of 25% (2/8) and 100% (5/5), respectively. Only 5 ECMO patients (8%) underwent coronary revascularization with 1 survivor.

CONCLUSIONS

The 90-day mortality represented perioperative outcomes better than 30-day mortality. Patients on ECMO, which extended the survival time, had 56% 90-day mortality. Coronary revascularization showed a salvaging effect, although the case number was small.Subj collection: 116, 137, 141.

Acquired anomalies of the coronary arteries after arterial switch operation. Usefulness of coronary computed tomography angiography and impact on follow-up

INTRODUCTION

Mortality and morbidity in patients with transposition of the great arteries after an arterial switch operation depends mainly on the status of coronary perfusion. Coronary computed tomography angiography (CCTA) provides accurate information on coronary morphology, however its use in these patients is not yet routine procedure.

OBJECTIVE

We sought to assess its accuracy to identify acquired coronary anomalies in this population, compared to conventional angiography in a subset of patients, and assess its impact on postoperative management.

METHODS

Retrospective analysis of clinical data on transposition of the great arteries in patients who underwent CCTA between January 2013 and September 2017.

RESULTS

Between January 2013 and September 2017, 18 patients underwent CCTA. Seven patients (39%) disclosed iatrogenic coronary lesions (stenosis 1; kinking 2, occlusion 1; filiform coronary 3). The exam was performed in 78% of patients due to suggestion of myocardial ischemia (symptoms or altered exams). Only 16% needed to undergo additional exams, and in four patients the CCTA result modified therapeutic management. Conventional coronary angiography was also performed in 10 patients (55%), and in three cases, the results were discordant with underestimation or non-identification of coronary lesions on conventional angiography. The medium radiation dose used was 2.4 mSv and no complications after CT were reported.

CONCLUSION

CCTA accurately identified iatrogenic postoperative coronary lesions and it has proven to be superior to conventional angiography in this population. It should be performed routinely in this group of patients, even in the absence of symptoms.

Right ventricular afterload in repaired D-TGA is associated with inefficient flow patterns, rather than stenosis alone

Treatment of D- transposition of great arteries (DTGA) involves the Arterial Switch Operation (ASO), which can create PA branch stenosis (PABS) and alter PA blood flow energetics. This altered PA flow may contribute to elevated right ventricular (RV) afterload more significantly than stenosis alone. Our aim was to correlate RV afterload and PA flow characteristics using 4D flow cardiac magnetic resonance (CMR) imaging of a mock circulatory system (MCS) incorporating 3D printed replicas. CMR imaging and clinical characteristics were analyzed from 22 ASO patients (age 11.9 ± 8.7 years, 68% male). Segmentation was performed to create 3D printed PA replicas that were mounted in an MRI-compatible MCS. Pressure drop across the PA replica was recorded and 4D flow CMR acquisitions were analyzed for blood flow inefficiency (energy loss, vorticity). In post-ASO patients, there is no difference in RV mass (p = 0.07), nor RV systolic pressure (p = 0.26) in the presence or absence of PABS. 4D flow analysis of MCS shows energy loss is correlated to RV mass (p = 0.01, r = 0.67) and MCS pressure differential (p = 0.02, r = 0.57). Receiver operating characteristic curve shows energy loss detects elevated RV mass above 30 g/m² (p = 0.02, AUC 0.88) while index of PA dimensions (Nakata) does not (p = 0.09, AUC 0.79). PABS alone does not account for differences in RV mass or afterload in post-ASO patients. In MCS simulations, energy loss is correlated with both RV mass and PA pressure, and can moderately detect elevated RV mass. Inefficient PA flow may be an important predictor of RV afterload in this population.

A Simplified Approach to Predicting Reintervention in the Arterial Switch Operation

We investigated patients with transposition anatomy suitable for the arterial switch operation (ASO) to evaluate a simplified approach to prediction of reintervention. A retrospective review was performed of 180 consecutive patients who underwent ASO from 2009 to 2018. Patients were classified as Category I (n = 122) d-transposition of great arteries (dTGA) + intact ventricular septum, Category II (n = 28) dTGA + ventricular septal defect (VSD) and Category III (n = 30) dTGA + Aortic arch obstruction (AAO) +/- VSD or Taussig-Bing Anomaly (TBA) +/- AAO. Outcomes included reintervention-free survival (using Kaplan-Meier estimates) and predictors of reintervention. Median follow up was 3.3 (interquartile range 1.7-5.8) years with no difference between categories(P = 0.082). There were 3 mortalities- 2 early (one each in Category I and II) and one late (in Category I). Reintervention-free survival for the whole group at 1, 3, 5 and 8 years was 94%, 91%, 90% and 86% respectively. Conventional criteria predicting reintervention included the presence of TBA(P = 0.0054) and AAO(P = 0.027). Low birth weight did not predict reintervention(P = 0.2). When analyzed by category, multivariable analysis showed that patients in Category III carried a high risk of reintervention [Hazard risk (HR) = 7.43, 95% confidence interval (CI)=(2.39, 23.11), P < 0.001], but so did those in Category II [HR=6.90, 95% CI = (2.19, 21.75, P < 0.001] when compared to Category I. Conventional risk factors for technical difficulty may not be the best predictors of reintervention. A simplified approach highlights Category II patients (dTGA + VSD) as being at substantial risk of re-intervention, and not part of a low risk cohort.

Early and Late Outcomes after Arterial Switch Operation: A 40-Year Journey in a Single Low Case Volume Center

Background and Objectives: The results of the arterial switch operation in large congenital heart centers are excellent, and the results in small and medium centers are improving. The objective of this article is to share our experience utilizing the international knowledge transfer program to improve early and late arterial switch operation outcomes in our center. Materials and Methods: A retrospective analysis of patients who underwent the arterial switch operation in Vilnius University Santaros Clinics Cardiothoracic Surgery Center between 1977–2020 was performed. Results: A total of 127 consecutive arterial switch operations were performed in our center. Surgical mortality during the entire study period was 24.6%. Surgical mortality prior to the program, during the program, and after the program was 88.24%, 41.7%, and 5.81%, respectively (p < 0.0001). The surgical mortality of patients operated on during the last 10 years was 4%. The overall survival estimate for the 97 surviving patients was 96.9%, 94.9%, 93.8%, 93.8%, 93.8%, 93.8% at 1, 3, 5, 10, 15, and 20 years, respectively. Risk factors for early mortality included longer aortic cross-clamp time and operation prior to the knowledge transfer program. The only significant risk factor for late reintervention was concomitant aortic arch obstruction treated at the time of the arterial switch. Conclusions: The surgical treatment of transposition of the great arteries by means of an arterial switch with good results can be possible in low-to-medium volume congenital heart surgery centers. International knowledge transfer programs between high-expertise high-volume congenital heart centers and low-to-medium volume congenital heart centers may help to shorten the learning curve and improve early and late outcomes after an arterial switch. The risk factors for surgical mortality and intervention-free survival in low-volume surgical centers are similar to those in high-volume centers. Late arterial switch-related complications are similar to those among different-sized congenital heart centers.

Acquired anomalies of the coronary arteries after arterial switch operation. Usefulness of coronary computed tomography angiography and impact on follow-up

INTRODUCTION

Mortality and morbidity in patients with transposition of the great arteries after an arterial switch operation depends mainly on the status of coronary perfusion. Coronary computed tomography angiography (CCTA) provides accurate information on coronary morphology, however its use in these patients is not yet routine procedure.

OBJECTIVE

We sought to assess its accuracy to identify acquired coronary anomalies in this population, compared to conventional angiography in a subset of patients, and assess its impact on postoperative management.

METHODS

Retrospective analysis of clinical data on transposition of the great arteries in patients who underwent CCTA between January 2013 and September 2017.

RESULTS

Between January 2013 and September 2017, 18 patients underwent CCTA. Seven patients (39%) disclosed iatrogenic coronary lesions (stenosis 1; kinking 2, occlusion 1; filiform coronary 3). The exam was performed in 78% of patients due to suggestion of myocardial ischemia (symptoms or altered exams). Only 16% needed to undergo additional exams, and in four patients the CCTA result modified therapeutic management. Conventional coronary angiography was also performed in 10 patients (55%), and in three cases, the results were discordant with underestimation or non-identification of coronary lesions on conventional angiography. The medium radiation dose used was 2.4 mSv and no complications after CT were reported.

CONCLUSION

CCTA accurately identified iatrogenic postoperative coronary lesions and it has proven to be superior to conventional angiography in this population. It should be performed routinely in this group of patients, even in the absence of symptoms.

Oblique coronary transfer technique in arterial switch operation for transposition of the great arteries

BACKGROUND

Mortality rates after the arterial switch operation (ASO) for transposition of the great arteries (TGA) are still suboptimal mainly due to postoperative myocardial ischemia. The present study aimed to investigate the clinical impact of our modification of coronary transfer technique, wherein the coronary cuffs are transferred oblique to the pulmonary trunk to avoid torsion of the coronary arteries.

METHODS

From September 2010 to August 2020, all 37 consecutive patients who underwent ASO for TGA with our modification, that is, the oblique coronary transfer technique, were retrospectively reviewed. Cardiac dimensions and patency of the coronary arteries were examined by cineangiography, and hemodynamic parameters were measured by cardiac catheterization and transthoracic echocardiography.

RESULTS

During a median 5.3 years of postoperative follow-up, there were no deaths and no patient required mechanical circulatory support. Median left ventricular ejection fraction was 68.8% (interquartile range 66.8-71.0, minimum 54.6). All patients maintained normal sinus rhythm without arrhythmia, except in the early postoperative period. Five patients underwent unplanned re-intervention for peripheral pulmonary stenosis, but none for coronary insufficiency. The 8-year freedom from re-intervention rate was 85.6%. Among a total of 110 transplanted coronary arteries, 108 (98.2%) remained patent, and two circumflex arteries were occluded much later after surgery, although with preserved ventricular function due to compensatory growth of other coronary branches.

CONCLUSION

The oblique coronary transfer technique, which aims to avoid torsion of the coronary arteries, provides good patency of the coronary arteries and subsequent improvement of postoperative mortality rates following ASO.

Alternative pulmonary artery reconstruction technique in the arterial switch operation

OBJECTIVES

Late complications of arterial switch operations (ASO) for transposition of the great arteries, such as neo-pulmonary artery (PA) stenosis and/or neoaortic regurgitation, have been reported. We developed an alternative reconstruction method called the longitudinal extension (LE) method to prevent PA bifurcation stenosis (PABS).

METHODS

We identified 48 patients diagnosed with transposition of the great arteries and performed ASO using the Lecompte manoeuvre for neo-PA reconstruction. In 9 consecutive patients (from 2014), the LE method was performed (LE). Before 2014, conventional techniques were performed in 39 patients (C). The median body weight and age in the LE and C groups were 3.0 and 3.1 kg and 12 and 26 days, respectively. In the LE group, 1 patient underwent bilateral PA banding before ASO. In C, PA banding and arch repair were performed in 1 patient each. Patients who received concomitant procedures were included.

RESULTS

The median follow-up in LE and C groups was 1.9 and 10.1 years, respectively. Early mortality/late death was not found in group LE and in 1 patient in group C. Only 1 case required ascending aorta sliding plasty in LE, and 8 patients needed PA augmentation for PABS in C. The median velocity of right/left PA was measured as 1.6/1.9 m/s in LE and 2.1/2.3 m/s in C, so it showed a lower value in LE.

CONCLUSIONS

Excellent mid-term results were obtained with the LE method. It was considered a useful procedure in preventing PABS, which is a primary late complication of ASO. Further follow-up and investigations are needed.

Risk Factors for Reoperation After Arterial Switch Operation

OBJECTIVE

The timing and nature of and risk factors for reoperation after the arterial switch operation in the setting of d-transposition of the great arteries requires further elucidation.

METHODS

A total of 403 patients who underwent arterial switch operation from 1986 to 2017 were reviewed. Institutional preference was for pulmonary artery reconstruction using a pantaloon patch of fresh autologous pericardium. The targets for coronary artery reimplantation were identified by intermittent root distension. Multivariable analysis was used to identify risk factors for reoperation.

RESULTS

Median follow-up was 8.6 years (interquartile range [IQR]: 2-16.9). Pulmonary arterioplasty was the most common reoperation (n = 11, 2.7%) at 3.3 years (IQR: 1.4-11.4) postoperatively. Subvalvar right ventricular outflow tract reconstruction (RVOTR) was required in nine (2.2%) patients at 2.5 years (IQR: 1.1-5.3) postoperatively. Aortic valve repair or replacement (AVR/r) was required in seven (1.7%) patients at 13.6 years (IQR: 10.0-15.8) postoperatively. Aortic root replacement (ARR) and Coronary Artery Bypass Graft/coronary patch arterioplasty were required in five (1.2%) patients each at 13.6 years (IQR: 11.0-15.3) and 11.3 years (IQR: 2.3-13.6) postoperatively, respectively. Taussig-Bing anomaly was a risk factor for any reoperation (P = .034). Risk factors for specific reoperations included ventricular septal defect for AVR/r (P = .038), Taussig-Bing anomaly for RVOTR (P = .004), and pulmonary artery banding for ARR (P = .028).

CONCLUSIONS

Pantaloon patch pulmonary artery reconstruction and intermittent neo-aortic root distension during coronary reimplantation have minimized respective outflow tract reoperations. Certain anatomic subsets carry different risks for late reoperation, and pulmonary artery and/or RVOT reinterventions tend to occur sooner than aortic reinterventions. Special attention to these higher risk subpopulations will be critical to optimizing lifelong outcomes.

Long-Term Survival and Freedom From Coronary Artery Reintervention After Arterial Switch Operation for Transposition of the Great Arteries: A Population-Based Nationwide Study

Background The aim of this study was to evaluate long-term survival and freedom from coronary artery reintervention after the arterial switch operation (ASO). Methods and Results This single-center nationwide retrospective study included consecutive children who underwent ASO between 1990 and 2016 (n=605). Long-term outcomes were obtained by cross-mapping individual data with the National Death Registry and the National Registry of Cardiovascular Interventions for adults. A control group was randomly retrieved at a 1:10 ratio from the National Birth and Death Registries. Early mortality was 3.3% and late mortality was 1.7% during a median follow-up of 10 (interquartile range, 5-16) years. The probability of overall survival at 20 years after ASO was 94.9% compared with 99.5% in the background population (hazard ratio [HR] 15.6; 95% CI, 8.9-27.5, P<0.001). Independent multivariable predictors of worse survival were an intramural coronary artery (HR, 5.2; 95% CI, 1.8-15.2, P=0.002) and period of ASO 1990 to 1999 (HR, 4.6; 95% CI, 1.5-13.6, P<0.001). Fourteen patients (2.3%) required 16 coronary artery reoperations. Freedom from coronary artery reintervention at 20 years after ASO was 96%. The only independent multivariable predictor associated with a higher hazard for coronary artery reintervention was an intramural coronary artery (HR, 33.9; 95% CI, 11.8-97.5, P<0.001). Conclusions Long-term survival after ASO is excellent. Coronary artery reinterventions are rare. An intramural coronary artery was an independent predictor associated with a higher risk for coronary artery reintervention and death, regardless of the surgical period.

Long-term outcome after the arterial switch operation: 43 years of experience

OBJECTIVES

The objective of this study was to assess our 43-year experience with arterial switch operation (ASO) for transposition of the great arteries (TGA) by analysing cardiac outcome measures (hospital and late mortality, reoperations and catheter interventions, significant coronary artery obstruction) and to identify risk factors for reoperation and catheter interventions.

METHODS

A total of 490 patients who underwent ASO for TGA from 1977 to 2020 were included in this retrospective, single-centre study. Data on reoperation and catheter intervention of hospital survivors were estimated by the Kaplan-Meier method and compared using a long-rank test. Risk factors for reoperation and/or catheter intervention were assessed by multivariate Cox regression analysis.

RESULTS

Hospital mortality occurred in 43 patients (8.8%), late death in 12 patients (2.9%) and 43 patients were lost to follow-up. Median follow-up time of 413 hospital survivors was 15.6 (interquartile range 7.0-22.4) years. Reoperations were performed in 83 patients (117 reoperations). Neoaortic valve regurgitation with root dilatation was the second most common indication for reoperation (15/83 patients, 18.1%) after right ventricular outflow tract obstruction (50/83 patients, 60.2%). Risk factors for any reoperation on multivariable analysis were: TGA morphological subtype [TGA with ventricular septal defect: hazard ratio (HR) = 1.99, 95% confidence interval (CI) 1.18-3.36; P = 0.010 and Taussig-Bing: HR = 2.17, 95% CI 1.02-4.64; P = 0.045], aortic arch repair associated with ASO (HR = 3.03, 95% CI 1.62-5.69; P = 0.001) and a non-usual coronary artery anatomy (HR = 2.41, 95% CI 1.45-4.00; P = 0.001). One hundred and one catheter interventions were performed in 54 patients, usually for relief of supravalvular pulmonary stenosis (44/54 patients, 81.5%) or arch obstruction (10/54 patients, 18.5%). Main risk factor for catheter intervention on multivariable analysis was aortic arch repair associated with ASO (HR = 2.95, 95% CI 1.37-6.36; P = 0.006). Significant coronary artery stenosis was relatively uncommon (9/413 patients, 2.2%) but may be underrepresented.

CONCLUSIONS

Patients after ASO typically have good long-term clinical outcomes but reoperations and interventions remain necessary in some patients. Neoaortic valve regurgitation with root dilatation is the second most common indication for reoperation after right ventricular outflow tract obstruction and an increasing need for neoaortic valve and root redo surgery in future is to be expected.

Is arterial switch operation possible with neonatology-focused intensive care unit modality

Background

In this study, we aimed to examine the feasibility of arterial switch operation and its perioperative management with neonatology-focused intensive care modality in a region of Turkey where the birth rate and the number of asylum seekers who had to leave their country due to regional conflicts are high.

Methods

Between December 2017 and June 2020, a total of 57 patients (48 males, 9 females; median age: 12.2 days; range, 2 to 50 days) who were diagnosed with transposition of the great arteries in our clinic and underwent arterial switch operation were retrospectively analyzed. All patients were followed by the neonatologist in the neonatal intensive care unit during the preoperative and postoperative period.

Results

Thirty-eight (66.7%) patients had intact ventricular septum, 16 (28.1%) had ventricular septal defect, two (3.5%) had coarctation of the aorta, and one (1.7%) had Taussig-Bing anomaly. Coronary artery anomaly was present in 14 (24.5%) patients. The most common complications in the intensive care unit were renal failure requiring peritoneal dialysis in seven (12.3%) patients, supraventricular tachyarrhythmia in six (10.5%) patients, and eight (14%) patients left their chests open. The median length of stay in intensive care unit was 13.8 (range, 9 to 25) days and the median length of hospital stay was 24.5 (range, 16 to 47) days. The overall mortality rate for all patients was 12.3% (n=7). The median follow-up was 8.2 months. A pulmonary valve peak Doppler gradient of ≥36 mmHg was detected in five patients (8.7%) who were followed, and these patients were monitored by providing medical treatment. None of the patients needed reoperation or reintervention.

Conclusion

We believe that arterial switch operation, one of the complex neonatal cardiac surgery, can be performed with an acceptable mortality and morbidity rate with the use of neonatology-focused intensive care modality, which is supported by pediatric cardiology and pediatric cardiac surgery.

Reference Values for Ventricular Volumes and Pulmonary Artery Dimensions in Pediatric Patients with Transposition of the Great Arteries After Arterial Switch Operation

BACKGROUND

Pulmonary artery (PA) anatomy in patients with transposition of the great arteries (TGA) after arterial switch operation (ASO) with Lecompte manoeuvre is different compared to healthy subjects, and stenoses of the PA are common. Magnetic resonance imaging (MRI) is an excellent imaging modality to assess PA anatomy in TGA patients. However, disease-specific reference values for PA size are scarce.

PURPOSE

To establish disease-specific reference ranges for PA dimensions and for biventricular volumes and mass.

STUDY TYPE

Retrospective.

SUBJECTS

A total of 69 pediatric patients with TGA after ASO (median age 12.6 years; range 5-17.8 years; 13 females and 56 males).

FIELD STRENGTH/SEQUENCE

3.0 T, steady-state free precession (SSFP) and gradient echo cine sequences and four-dimensional time-resolved magnetic resonance angiography with keyhole.

ASSESSMENT

Right and left PA (RPA, LPA) were each measured at three locations during its course around the aorta. Ventricular volumes, mass, and ejection fraction were measured from a stack of short axis cine images.

STATISTICAL TESTS

The lambda-mu-sigma (LMS) method of Cole and Green, univariate and multivariate linear models, and t-test.

RESULTS

Centile graphs and tables for PA dimensions, biventricular volumes, mass, and ejection fraction were created. Univariate linear analysis showed significant associations (P < 0.05) between body surface area (BSA), height, and weight with systolic MPA and RPA diameter. In multivariate linear analysis, only BSA remained a strong predictor for main PA and RPA diameters. For biventricular volumes, the univariate linear model revealed a strong influence of BSA, height, weight, and age (all P < 0.05). On multivariate linear analysis, only body height remained associated.

DATA CONCLUSION

Uni- and multivariate linear analyses showed a strong association between BSA and PA diameters, as well as between height and biventricular volumes, and therefore, centile tables and graphs are presented accordingly. Our data may improve MR image interpretation and may serve as a reference in future studies.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY STAGE: 2.

An early health technology assessment of 3D anatomic models in pediatric congenital heart surgery: potential cost-effectiveness and decision uncertainty

Background: Three-dimensional anatomic models have been used for surgical planning and simulation in pediatric congenital heart surgery. This research is the first to evaluate the potential cost-effectiveness of 3D anatomic models with the intent to guide surgeons and decision makers on its use.Method: A decision tree and subsequent Markov model with a 15-year time horizon was constructed and analyzed for nine cardiovascular surgeries. Epidemiological, clinical, and economic data were derived from databases. Literature and experts were consulted to close data gaps. Scenario, one-way, threshold, and probabilistic sensitivity analysis captured methodological and parameter uncertainty.Results: Incremental costs of using anatomical models ranged from -366€ (95% credibility interval: -2595€; 1049€) in the Norwood operation to 1485€ (95% CI: 1206€; 1792€) in atrial septal defect repair. Incremental health-benefits ranged from negligible in atrial septal defect repair to 0.54 Quality Adjusted Life Years (95% CI: 0.06; 1.43) in truncus arteriosus repair. Variability in the results was mainly caused by a temporary postoperative quality-adjusted life years gain.Conclusion: For complex operations, the implementation of anatomic models is likely to be cost-effective on a 15 year time horizon. For the right indication, these models thus provide a clinical advantage at an acceptable cost.

Preoperative Anemia and Outcomes After Corrective Surgery in Neonates With Dextro-Transposition of the Great Arteries

OBJECTIVES

The authors aimed to assess whether untreated preoperative anemia was associated with increased risk for adverse outcomes after the arterial switch operation in neonates with dextro-transposition of the great arteries (d-TGA).

DESIGN

Retrospective cohort study.

SETTING

Single cardiac surgery center.

PARTICIPANTS

Eighty-two newborns with d-TGA.

INTERVENTIONS

The authors categorized the cohort into the following two groups: the infants with preoperative anemia group (defined as a hematocrit <0.40 L/L) and the control group.

MEASUREMENTS AND MAIN RESULTS

Preoperative anemia was diagnosed in 21 (25.6%) infants. Anemic infants received intraoperative red blood cell transfusions significantly more often than controls (81.0% v 34.4%, p < 0.001). No differences were observed in the incidence of adverse events, duration of hospitalization (median 27 days v 26 days, p = 0.881), and mortality (0% v 4.9%, p = 0.566). Postnatal hematocrit was the only variable independently associated with preoperative anemia in multivariate logistic regression analysis (unit odds ratio, 0.832; 95% confidence interval, 0.743-0.931; p = 0.001).

CONCLUSIONS

Untreated preoperative anemia was not associated with adverse outcomes in neonates undergoing reparative surgery for d-TGA.

Long-term outcomes of the arterial switch operation

OBJECTIVES

The arterial switch operation (ASO) has excellent early outcomes in the modern era. We sought to determine the long-term outcomes in patients who underwent an ASO at a single institution.

METHODS

Patients who underwent an ASO between 1983 and 2015 were identified from the hospital database and retrospectively reviewed using hospital records.

RESULTS

From 1983 to 2015, 844 patients with a biventricular circulation underwent an ASO. There were 28 (3.3%, 28/844) early deaths. Follow-up was available for 94% (729/774) of local patients after hospital discharge. Median follow-up was 15 years (interquartile range, 8-20 years). There were 187 (26%, 187/729) patients with more than 20 years of follow-up and 95 (13%, 95/729) patients with more than 25 years of follow-up. Overall survival was 95% (95% confidence interval [CI], 94%-97%) at 10 and 25 years after the ASO. At 25 years after ASO, freedom from overall reintervention was 77% (95% CI, 73%-81%), freedom from reoperation on the neoaortic root or neoaortic valve was 92% (95% CI, 88%-95%), and freedom from coronary reoperation was 99% (95% CI, 98%-99.7%). Left ventricular (LV) systolic function was normal in 595 of 609 (98%) of patients who had LV function quantified at latest follow-up. Of the 95 patients with more than 25 years of follow-up after ASO, 6 (6.3%) had at least moderate neoaortic valve regurgitation (AR) and 8 (8.4%) had undergone replacement of the neoaortic valve.

CONCLUSIONS

Overall, survivors of ASO have excellent late survival and normal LV systolic function into adult life. However, AR and reoperation on the neoaortic valve remains an issue for older patients.

Clinical Outcome of Patients with Transposition of the Great Arteries and Intramural Coronary Artery

To review the early and intermediate outcomes of patients with transposition of the great arteries (TGA) and intramural coronary artery (IMCA) who underwent arterial switch operation (ASO) at our center. Among 450 patients with TGA who underwent an ASO between 2010 and 2018, 26 (5.8%) patients were identified with IMCA. The left coronary artery was intramural in 21 of 26 patients. We adopted coronary transfer using double coronary buttons with unroofed intramural course for all 26 patients. Early mortality for patients with IMCA was 3 of 26 (11.5%) compared with 10 of 424 (2.4%) for those without IMCA (p = 0.007). Six patients suffered major adverse events, including extracorporeal membrane oxygenation support in 3 patients, delayed sternal closure in 6 patients. The follow-up was available for all 23 survivors, with the mean follow-up period of 73.5 ± 28.7 months. There was no late death and reinterventions, and all patients were asymptomatic at last follow-up. One patient exhibited moderate neopulmonary regurgitation, and 1 patient presented with distal stenosis of the right pulmonary artery. Coronary transfer using double coronary buttons with unroofed intramural course was a good option for patients with TGA and IMCA. With this technique, ASO could be performed with optimal early and intermediate outcomes.

Oxygen Uptake Efficiency Slope is Strongly Correlated to VO2peak Long-Term After Arterial Switch Operation

After the arterial switch operation (ASO) for transposition of the great arteries (TGA), many patients have an impaired exercise tolerance. Exercise tolerance is determined with cardiopulmonary exercise testing by peak oxygen uptake (VO_2peak). Unlike VO_2peak, the oxygen uptake efficiency slope (OUES) does not require a maximal effort for interpretation. The value of OUES has not been assessed in a large group of patients after ASO. The purpose of this study was to determine OUES and VO_2peak, evaluate its interrelationship and assess whether exercise tolerance is related to ventricular function after ASO. A cardiopulmonary exercise testing, assessment of physical activity score and transthoracic echocardiography (fractional shortening and left/right ventricular global longitudinal peak strain) were performed to 48 patients after ASO. Median age at follow-up after ASO was 16.0 (IQR 13.0-18.0) years. Shortening fraction was normal (36 ± 6%). Left and right global longitudinal peak strain were reduced: 15.1 ± 2.4% and 19.5 ± 4.5%. This group of patients showed lower values for all cardiopulmonary exercise testing parameters compared to the reference values: mean VO_2peak% 75% (95% CI 72-77) and mean OUES% 82(95% CI 77-87); without significant differences between subtypes of TGA. A strong-to-excellent correlation between the VO_2peak and OUES was found (absolute values: R = 0.90, p < 0.001; normalized values: R = 0.79, p < 0.001). No correlation was found between cardiopulmonary exercise testing results and left ventricle function parameters. In conclusion, OUES and VO_2peak were lower in patients after ASO compared to reference values but are strongly correlated, making OUES a valuable tool to use in this patient group when maximal effort is not achievable.

4D flow MRI applications in congenital heart disease

Advances in the diagnosis and management of congenital heart disease (CHD) have resulted in a growing population of patients surviving well into adulthood and requiring lifelong follow-up. Flow quantification is a central component in the assessment of patients with CHD. 4D flow magnetic resonance imaging (MRI) has emerged as a tool that enables comprehensive study of flow. It involves the acquisition of a three-dimensional time-resolved volume with velocity encoding in all three spatial directions along the cardiac cycle. This allows flow quantification and visualization of blood flow patterns as well as the study of advanced hemodynamic parameters as kinetic energy and wall shear stress. 4D flow MRI-based study of flow has given insight into the altered hemodynamics in CHD particularly in bicuspid aortic valve disease and Fontan circulation. The aim of this review is to discuss the expanding clinical and research applications of 4D flow MRI in CHD as well its limitations.Key Points• Three-dimensional velocity encoding allows not only flow quantification but also the visualization of multidirectional flow patterns and the study of advanced hemodynamic parameters.• 4D flow MRI has added insight into the abnormal hemodynamics involved in congenital heart disease in particular in bicuspid aortic valve and Fontan circulation.• The main limitation of 4D flow MRI in congenital heart disease is the relatively long scan duration required for the complete coverage of the heart and great vessels with adequate spatiotemporal resolution.

Single-ventricle palliation in children with atrioventricular septal defect and transposition of the great arteries: 45 years of experience

BACKGROUND

The association of atrioventricular septal defect and transposition of the great arteries is very rare. As a rule, these patients have unbalanced ventricles. However, there have been no studies describing the results of single-ventricle palliation in these children.

METHODS

All children who underwent surgery with a diagnosis of atrioventricular septal defect and transposition of the great arteries were included in the study. Data were obtained from medical records.

RESULTS

A total of 38 patients with atrioventricular septal defect and transposition of the great arteries underwent single-ventricle palliation at the study institution between 1971 and 2016. The mean follow-up was 12.4 years (median: 14.6 years, range 2-43.3 years). Most children had unbalanced atrioventricular septal defect (94.7%, 36/38). Survival was 67.6% (95% confidence interval [CI]: 50.0-80.2%) at 10 years and 57.8% (95% CI: 38.0-73.4%) at 20 years. By 10 years, 58.6% (95% CI: 40.8-72.7%) had progressed to Fontan completion, while 32.5% (95% CI: 18.2-47.6%) had died. In patients achieving Fontan completion, 20-year event-free survival was 73.3% (95% CI: 34.8-91.3%), while 5.0% (95% CI: 0.4-20.5%) had undergone cardiac transplantation and 21.7% (95% CI: 3.2-50.8%) had undergone takedown of the Fontan circulation. Freedom from atrioventricular valve surgery was 57.0% (95% CI: 37.2-72.7%) at 10 and 20 years.

CONCLUSIONS

The association of atrioventricular septal defect and transposition of the great arteries is very rare, and most of these children have unbalanced ventricles. Single-ventricle palliation results in 25-year overall survival of 50%. However, in patients, who had Fontan completion, survival was 75% at 25 years after Fontan operation.

Perinatal and perioperative factors associated with mortality and an increased need for hospital care in infants with transposition of the great arteries: A nationwide 11-year population-based cohort

INTRODUCTION

Newborn infants with transposition of the great arteries (d-TGA) need immediate care for an optimal outcome. This study comprised a nationwide 11-year population-based cohort of d-TGA infants, and assessed whether the implementation of a nationwide systematic fetal screening program, or other perinatal, or perioperative factors, are associated with mortality or an increased need for hospital care.

MATERIAL AND METHODS

The national cohort consisted of all live-born infants with simple d-TGA (TGA ± small ventricular septal defect, n = 127) born in Finland during 2004-2014. Data were collected from six national registries. Prenatal diagnosis and perinatal and perioperative factors associated with mortality and length of hospitalization were evaluated.

RESULTS

Preoperative mortality was 7.9%, and the total mortality was 8.7%. The prenatal detection rate increased after introducing systematic fetal anomaly screening from 5.0% to 37.7% during the study period (P < .0001), but the total mortality rate remained unchanged. All prenatally diagnosed infants (n = 27) survived. Lower gestational age (odds ratio 0.68, P = .012) and higher maternal age at birth (odds ratio 1.16, P = .036) were associated with increased mortality in multivariable analysis. Older infant age at time of operation (P = .002), longer aortic clamp time (P < .001), and higher maternal body mass index (P = .027) were associated with longer initial hospital stay. An extended need for hospital care during the first year of life was multi-factorial.

CONCLUSIONS

In our cohort, none of the prenatally diagnosed d-TGA infants died. As a result of the limited prenatal detection rates, however, the sample size was insufficient to reach statistical significance. The d-TGA infants born with lower gestational age and to older mothers had increased mortality.

Transposition of the great vessels and intact ventricular septum: is there an age limit for the arterial switch? Personal experience and review of the literature

OBJECTIVE

Prognosis of the transposition of the great arteries has completely changed since the introduction of the arterial switch. Time limit to perform this intervention is still controversial. The aim of this study is to demonstrate the early and late outcome of primary arterial switch operation beyond the age of months.

METHODS

We included all patients with the diagnosis of transposition of the great arteries with intact ventricular septum beyond the age of 8 weeks who underwent primary arterial switch operation. The procedures were performed by the same surgeon, in two different institutes. Patients who had transposition of the great arteries and associated anomalies (except atrial septal defect and persistent arterial duct) were excluded. Ventricular shape, geometry, and mass were not considered during the decision on procedure type.

RESULTS

In the study, 11 patients with the diagnosis of simple d-transposition of the great arteries beyond 8 weeks were undergone primary arterial switch operation with a mean age of 90.63 days (60-137 days), and 7 patients had a Rashkind procedure. All patients had squashed left ventricle shape with preserved function. The sternum was left open in 10 patients. Extracorporeal membrane oxygenation support was necessary in 45.45% of cases. The mean mechanical ventilation time was 7.27 days (1-16 days). No mortality was recorded until now. Post-operatory left ventricular function was preserved in 90.9% of the patients. Only one patient had mild myocardial dysfunction at the time of discharge.

CONCLUSIONS

Primary arterial switch procedure can still be the best surgical option in patients with the diagnosis of transposition of the great arteries with intact ventricular septum beyond 8 weeks of age, providing that mechanical circulatory support and an expert cardiac intensive care unit service are available.

Technical Performance Score's Association With Arterial Switch Operation Outcomes

BACKGROUND

Outcomes after the arterial switch operation (ASO) for dextro-transposition of the great arteries have improved significantly since its inception in the 1980s. This study reviews contemporaneous outcomes and predictors for late reinterventions after ASO.

METHODS

We retrospectively reviewed patients who underwent ASO for dextro-transposition of the great arteries from 1997 to 2017. Technical performance score (TPS) class (class 1, trivial or no residua; class 2, minor residua; class 3, major residua or reintervention) was assigned at discharge based on echocardiographic evaluation of components of the ASO. Multivariable Cox regression identified patient- and procedure-specific factors associated with postdischarge reinterventions.

RESULTS

Among 598 patients, 410 (69%) underwent ASO and 188 (31%) underwent ASO with ventricular septal defect repair. Median age at surgery was 5 days (interquartile range, 3 to 7); median follow-up time was 8.2 years; 408 (68%) were male; 50 (8.3%) were premature; and 10 (1.7%) had noncardiac anomalies or syndromes. Survival to hospital discharge was 98% (n = 591). Among 349 patients with follow-up, freedom from unplanned reintervent2ion at 5 years was 99% for TPS class 1, compared with 84% for class 2 and 30% for class 3. On multivariable Cox regression, classes 2 and 3 had significantly higher hazard for reintervention (class 2 hazard ratio 10.6; 95% confidence interval, 2.5 to 44.2; P = .001; class 3 hazard ratio 58.2, 95% confidence interval, 13.1 to 259; P < .001).

CONCLUSIONS

At our center, ASO was associated with relatively low mortality. Class 2 and class 3 TPS were the most important independent predictors of reinterventions after discharge. Therefore, TPS can serve as a tool for identifying high-risk patients who warrant closer follow-up.

Twenty-Three-Year Experience With the Arterial Switch Operation: Expectations and Long-Term Outcomes

We aimed to describe the short- and long-term outcomes of patients after an arterial switch operation (ASO) at a single institution during a 23-year period. A retrospective chart review of all patients <18 months of age who underwent an ASO between January 1995 and March 2018 at Texas Children's Hospital, Houston, TX was performed. Primary endpoints include mortality and reintervention. Perioperative mortality was defined as mortality occurring in-hospital and/or <30 days after surgery. Survival and freedom-from-reintervention were analyzed using Kaplan-Meier method, log-rank tests, and Cox regression models. The cohort included 394 patients. Diagnoses included 204 patients (52%) with intact ventricular septum, 137 (35%) with a ventricular septal defect, 17 (4%) with a ventricular septal defect and left ventricular outflow tract obstruction (LVOTO), and 36 (9%) with Taussig-Bing anomaly. Median age at surgery was 8 days (range: 1 day to 17 months) and median weight was 3.4 (range: 0.8-12.0) kg. Overall perioperative mortality was 1.3% (n = 5), 0.3% (n = 1) since 1999. Overall survival at 5, 10, and 15 years was 98.2%, 97.8%, and 97.8%, respectively. Perioperative morality was associated with prematurity (P = 0.012), <2.5 kg (P< 0.001), and longer circulatory arrest (P = 0.024) after univariate analysis. Reintervention was associated with a longer cross-clamp time (P < 0.001), <2.5 kg (P = 0.009), LVOTO resection (P = 0.047), and genetic syndrome (P= 0.011) after multivariable analysis. Current ASO expectations should include a perioperative mortality risk of <1% and good long-term survival. Reinterventions are more frequent in patients <2.5 kg, concomitant LVOTO resection, a genetic syndrome, and longer cross-clamp time.