The impact of unilateral pulmonary artery stenosis on right ventricular to pulmonary arterial coupling in patients with transposition of the great arteries.

BACKGROUND: Unilateral pulmonary artery (PA) stenosis is common in the transposition of the great arteries (TGA) after arterial switch operation (ASO) but the effects on the right ventricle (RV) remain unclear. AIMS: To assess the effects of unilateral PA stenosis on RV afterload and function in pediatric patients with TGA-ASO. METHODS: In this retrospective study, eight TGA patients with unilateral PA stenosis underwent heart catheterization and cardiac magnetic resonance (CMR) imaging. RV pressures, RV afterload (arterial elastance [Ea]), PA compliance, RV contractility (end-systolic elastance [Ees]), RV-to-PA (RV-PA) coupling (Ees/Ea), and RV diastolic stiffness (end-diastolic elastance [Eed]) were analyzed and compared to normal values from the literature. RESULTS: In all TGA patients (mean age 12 ± 3 years), RV afterload (Ea) and RV pressures were increased whereas PA compliance was reduced. RV contractility (Ees) was decreased resulting in RV-PA uncoupling. RV diastolic stiffness (Eed) was increased. CMR-derived RV volumes, mass, and ejection fraction were preserved. CONCLUSION: Unilateral PA stenosis results in an increased RV afterload in TGA patients after ASO. RV remodeling and function remain within normal limits when analyzed by CMR but RV pressure-volume loop analysis shows impaired RV diastolic stiffness and RV contractility leading to RV-PA uncoupling.

Repair of complex transposition of great arteries: What is the best technique to avoid outflow tract obstructions?

OBJECTIVES: This study aimed to evaluate the short-/mid-term outcome of patients with complex dextro (d)-/levo (l)-transposition of the great arteries (TGA), ventricular septal defect and left ventricular outflow tract obstructions. METHODS: A single-centre, retrospective review of all complex dextro-TGA (n = 85) and levo-TGA (n = 22) patients undergoing different surgeries [Arterial switch operation + left ventricular outflow tract obstruction-resection (ASO-R), half-turned truncal switch/Mair (HTTS), Nikaidoh and Rastelli] between May 1990 and September 2022 was performed. Groups were analysed using Kruskal-Wallis test with post hoc pairwise comparison and Kaplan-Meier time-to-event models. RESULTS: A total of 107 patients [ASO-R (n = 20), HTTS (n = 23), Nikaidoh (n = 21), Rastelli (n = 43)] were included, with a median age of 1.0 year (0.5-2.5) and surgical repair median follow-up was 3.8 years (0.3-10.5). Groups did not differ in respect to early postoperative complications/early mortality. Five-year overall survival curves were comparable: ASO-R 78.9% (53.2-91.5), HTTS 75.3% (46.8-89.9), Nikaidoh 85% (60.4-94.9) and Rastelli 83.9% (67.5-92.5), P = 0.9. Highest rates of right ventricular outflow tract (RVOT) reinterventions [33.3% and 32.6% (P = 0.04)] and reoperations [28.6% and 32.6% (P = 0.02)] occurred after Nikaidoh and Rastelli procedures. However, overall freedom from RVOT reinterventions and RVOT reoperations at 5 years did not differ statistically significantly between the groups (ASO-R, HTTS, Nikaidoh and Rastelli): 94.4% (66.6-99.2), 69.1% (25.4-90.5), 67.8% (34-86.9), 64.4% (44.6-78.7), P = 0.2, and 90.0% (65.6-97.4), 91% (50.8-98.7), 65.3% (32.0-85.3) and 67.0% (47.4-80.6), P = 0.3. CONCLUSIONS: Surgical repair of complex dextro-/levo-TGA can be performed with satisfying early/mid-term survival. RVOT reinterventions/reoperations were frequent, with highest rates after Nikaidoh and Rastelli procedures. Left ventricular outflow tract obstruction reoperations were rare with zero events after Nikaidoh and HTTS procedures.

Perioperative Factors and Radiographic Severity Scores for Predicting the Duration of Mechanical Ventilation After Arterial Switch Surgery.

OBJECTIVES: Cardiac surgery on cardiopulmonary bypass (CPB) during the neonatal period can cause perioperative organ injuries. The primary aim of this study was to determine the incidence and risk factors associated with postoperative mechanical ventilation duration and acute lung injury after the arterial switch operation (ASO). The secondary aim was to examine the utility of the Brixia score for characterizing postoperative acute lung injury (ALI). DESIGN: A retrospective study. SETTING: A single-center university hospital. PARTICIPANTS: A total of 93 neonates with transposition of great arteries with intact ventricular septum (dTGA IVS) underwent ASO. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: From January 2015 to December 2022, 93 neonates with dTGA IVS were included in the study. The cohort had a median age of 4.0 (3.0-5.0) days and a mean weight of 3.3 ± 0.5 kg. About 63% of patients had ≥48 hours of postoperative mechanical ventilation after ASO. Risk factors included prematurity, post-CPB transfusion of salvaged red cells, platelets and cryoprecipitate, and postoperative fluid balance by univariate analysis. The larger transfused platelet volume was associated with the risk of ALI by multivariate analysis. The median baseline Brixia scores were 11.0 (9.0-12.0) and increased significantly in the postoperative day 1 in patients who developed moderate ALI 24 hours after admission to the intensive care unit (15.0 [13.0-16.0] v 12.0 [10.0-14.0], p = 0.046). CONCLUSIONS: Arterial switch operation results in a high incidence of ≥48-hour postoperative mechanical ventilation. Blood component transfusion is a potentially modifiable risk factor. The Brixia scores also may be used to characterize postoperative acute lung injury.

Prevalence of Branch Pulmonary Artery Reintervention Following the Arterial Switch Operation.

BACKGROUND: The arterial switch operation (ASO) is the preferred surgical procedure used to correct dextro-transposition of the great arteries. A known complication of the ASO is branch pulmonary arteries (PAs) stenosis, which may require reintervention. Our goal is to determine the frequency of reintervention after the ASO and any factors associated with reintervention. METHODS: This was a single center, retrospective study of infants who underwent the ASO from June 6, 2011 to February 21, 2021. The primary outcome was the prevalence of reintervention on the PAs following the ASO. RESULTS: Sixty-eight infants were analyzed; 9 (13%) patients had 10 reinterventions. The mean age at time of the ASO was 6.52 ± 6.63 days; weight was 3.34 ± 0.57 kg. Those with a reintervention had a longer bypass time (P = .047). Mean age at reintervention was 0.80 ± 0.72 years; mean time from the ASO to reintervention was 0.799 ± 0.717 years. Six surgical procedures, two stent placements, and four balloon angioplasties were performed on a total of 13 branch PAs. There was no increased risk for reintervention on the right versus left PA. After reintervention, there was an improvement in the minimal PA diameter and echo gradient. There were no adverse events or mortality related to the reintervention. Mean follow-up was 6.17 ± 2.94 years. CONCLUSION: The prevalence of branch PA reintervention following the ASO in our cohort was 13%. There is an association between longer cardiopulmonary bypass time and reintervention. After reintervention, there was an increase in PA diameter and a decrease in echo gradient.

Biomarkers in transposition of the great arteries after arterial switch operation: A pilot trial with deep phenotyping.

INTRODUCTION: Transposition of the great arteries (TGA) is a cyanotic congenital heart defect for which the arterial switch operation (ASO) is the preferred surgical repair. This study wanted to investigate whether a panel of biomarkers could identify morphologic as well as hemodynamic changes obtained by cardiac magnetic resonance (CMR). METHODS: Forty-four adult patients were included. Blood samples were collected to measure a broad range of biomarkers (galectin-3, ST2, GDF-15, PINP, ICTP, PIIINP, IGF-1, NT-proBNP, and hs-Tn). CMR was performed at rest and during exercise to assess cardiac function and morphology. Explorative statistics were performed between biomarker levels and CMR findings. RESULTS: All patients were asymptomatic. While galectin-3, GDF-15, and NT-proBNP levels were within normal ranges, increased ST2, PINP, PIIINP, and ICTP levels were found in 20.5%, 34.1%, 45.5%, and 27.3% of patients, respectively. Moreover, 3 and 2 patients, respectively, showed elevated IGF-1 and hs-Tn levels. Although the ejection fraction of both ventricles was within normal limits, impaired cardiac reserve was found in 20 and 25% of patients for left and right ventricle, respectively. CMR revealed no evidence of diffuse interstitial fibrosis, while 4 patients showed focal ischemic scarring. However, no significant associations between serum biomarkers and CMR data could be detected. CONCLUSION: The results suggest that in asymptomatic ASO-repaired TGA patients serum level biomarkers are elevated and that this increase is not associated with morphological changes nor with a decreased cardiac reserve. Further study with larger sample sizes is required to draw conclusions with greater confidence.

Acute superficial and deep necrosis of lower limb following femoral arterial cannulation in a neonate undergoing arterial switch operation for transposition of great arteries.

Arterial lines are routinely used for hemodynamic monitoring and blood sampling in the operating room and in cardiac surgery intensive care unit. The complications related to arterial line insertion are very low; the knowledge of the relevant artery anatomy, skills and the experience of the operator and selection of a right size cannula plays a vital role in reducing morbidity related to arterial line insertion. We describe extensive superficial and deep necrosis of lower limb following arterial cannula insertion in a preterm neonate undergoing arterial switch procedure and discuss measures to prevent such a complication.

Unveiling the gothic aortic arch and cardiac mechanics: insights from young patients after arterial switch operation for d-transposition of the great arteries.

The arterial switch operation (ASO) has become the standard surgical treatment for patients with d-transposition of the great arteries. While ASO has significantly improved survival rates, a subset of patients develop a unique anatomical anomaly known as the gothic aortic arch (GAA). Understanding cardiac mechanics in this population is crucial, as altered mechanics can have profound consequences for cardiac function and exercise capacity. The GAA has been associated with changes in ventricular function, hemodynamics, and exercise capacity. Studies have shown a correlation between the GAA and decreased ascending aorta distensibility, loss of systolic wave amplitude across the aortic arch, and adverse cardiovascular outcomes. Various imaging techniques, including echocardiography, cardiac magnetic resonance imaging, and cardiac computed tomography, play a crucial role in assessing cardiac mechanics and evaluating the GAA anomaly. Despite significant advancements, gaps in knowledge regarding the prognostic implications and underlying mechanisms of the GAA anomaly remain. This review aims to explore the implications of the GAA anomaly on cardiac mechanics and its impact on clinical outcomes in young patients after ASO. Advancements in imaging techniques, such as computational modeling, offer promising avenues to enhance our understanding of cardiac mechanics and improve clinical management.

Paediatric quality of life in toddlers and children who underwent arterial switch operation beyond early neonatal period.

OBJECTIVES: The aim of this study was to evaluate the quality of life (QOL) of children who underwent the arterial switch operation (ASO) for Transposition of Great Arteries in our population and, specifically, to explore early modifiable factors and the influence of parental and socioeconomic factors on the QOL of these children. METHODS: Cross-sectional study using Paediatric Quality of Life Inventory™ 3.0 Cardiac Module was carried out on 3- to 12-year-old children who had undergone ASO between the years 2012-2018. Socioeconomic status was calculated using the modified Kuppuswamy scale (2019). Other clinical factors with possible bearing on the outcome were also analysed. RESULTS: Immediate survival after surgery was 196 out of 208 (94.2%) with an attrition of 19 patients (9.6%) over the follow-up period. Most surviving children (98.9%) had started formal schooling in age-appropriate classes. Two children had severe neuromotor impairment. The median cumulative health-related QOL score of the children was 97.9 (interquartile range 4.2) at 5.6 ± 1.27 years of life. The median scores each of the health-related QOL parameters, viz, heart problem symptoms, treatment compliance, perceived physical appearance, treatment-related anxiety, cognitive problems, and communication was 100 with negative skewing. CONCLUSIONS: Excellent QOL was observed in most children after ASO with the median total paediatric QOL scores in all domains of 97.9. Social factors did not show a statistically significant influence on the QOL parameters in the current cohort. The gradually declining trend across the age groups emphasizes the need for continued follow-up for early identification of possible correctable factors and initiating intervention to ensure good QOL into teenage and adulthood.

Right ventricular dissection after arterial switch operation.

Herein we present the right ventricular dissection and describe its successful management after arterial switch operation in a full-term male neonate. There are no evidence-based recommendations for the management of this rare complication. Our management included veno-arterial extracorporeal membrane oxygenation placement and delayed surgical evacuation of the dissecting haematoma with beneficial outcomes.

Decreased cardiac reserve in asymptomatic patients after arterial switch operation for transposition of the great arteries.

BACKGROUND: Exercise capacity is impaired in patients after arterial switch operation (ASO) for complete transposition of the great arteries. Maximal oxygen consumption is related with outcome. OBJECTIVES: This study assessed ventricular function by advanced echocardiography and cardiac magnetic resonance (CMR) imaging at rest and during exercise, to determine exercise capacity in ASO patients, and to correlate exercise capacity with ventricular function as potential early marker of subclinical impairment. METHODS: Forty-four patients (71% male, mean age 25 ± 4 years - range 18-40 years) were included during routine clinical follow-up. Assessment involved physical examination, 12­lead ECG, echocardiography, and cardiopulmonary exercise test (CPET) (day 1). On day 2 CMR imaging at rest and during exercise was performed. Blood was sampled for biomarkers. RESULTS: All patients reported New York Heart Association class I, the overall cohort had an impaired exercise capacity (80 ± 14% of predicted peak oxygen consumption). Fragmented QRS was present in 27%. Exercise CMR showed that 20% of patients had abnormal contractile reserve (CR) of the left ventricle (LV) and 25% had reduced CR of the right ventricle (RV). CR LV and CR RV were significantly associated with impaired exercise capacity. Pathological patterns on myocardial delayed enhancement and hinge point fibrosis were detected. Biomarkers were normal. CONCLUSION: This study found that in some asymptomatic ASO patients electrical, LV and RV changes at rest, and signs of fibrosis are present. Maximal exercise capacity is impaired and seems to be linearly related to the CR of the LV and the RV. Therefore, exercise CMR might play a role in detecting subclinical deterioration of ASO patients.

Fate After the Mustard Procedure for d-Transposition of the Great Arteries: Impact of Age, Complexity, and Atrial Tachyarrhythmias: A Single Center Experience.

Patients with dextro transposition of the great arteries (d-TGA) after atrial switch procedure are at risk to develop heart failure and arrhythmias during long-term follow-up. The present study aims to add knowledge on the fate of subjects after Mustard procedure during long-term follow-up into adulthood. A single center, retrospective chart review analysis was conducted. All subjects who had Mustard-type atrial switch procedure between 1969 and 1994 at our institution were included. A total of 92 subjects were included. Early postoperative death was reported in 2 subjects. Long-term follow-up was available in 49 survivors. Of those, 6 individuals died during further follow-up. Sudden cardiac death was the most prevalent cause for fatal outcome. Mortality during long-term follow-up was associated with the presence of additional cardiovascular malformations (complex d-TGA). Sinus node dysfunction was observed in 65% of the patients and atrial tachyarrhythmias were common in adult survivors (63%). Implantation of a pacemaker or a cardioverter defibrillator was required in 31% and 45% of those surviving into adulthood. Complications were frequently observed during follow-up after either pacemaker or cardioverter defibrillator implantation (43%) with lead failure being the most frequent complication. The aging population of patients after Mustard procedure is facing challenging problems mainly resulting from a failing systemic right ventricle, presence of associated cardiac malformations and the presence of atrial baffles associated with relevant atrial scars. Age, associated cardiac malformations, and atrial tachyarrhythmias seem to play a major role in determining the fate of patients with d-TGA after atrial switch procedures.

Arterial Switch Operation in Patients With Single Sinus Coronary Artery Anatomy: Risk Factors for Mortality From a Lower-Middle Income Country.

Background: This study evaluates mortality and intermediate outcomes of the arterial switch operation (ASO) for transposition or Taussig-Bing anomaly with single sinus coronary artery (CA) anatomy in a high-volume cardiac program in Vietnam. Methods: We retrospectively reviewed and performed risk factor analysis pertaining to 41 consecutive patients who presented with single sinus CA anatomy and who underwent ASO from January 2010 to December 2016 in our center. Results: The median age at operation was 43 days [interquartile range (IQR): 20-65] and the median weight was 3.6 kg (IQR: 3.4-4.0). Four in-hospital deaths (9.8%), of which one was related to coronary insufficiency. There were no late deaths, with a median follow-up time of 7.2 years. Survival for all patients with single sinus CA was 90.2% at 1 year and remained constant at 5 years and 10 years after ASO. The presence of a coexisting aortic arch anomaly was the only risk factor for overall mortality identified in this study (hazard ratio: 8.66, P = .031, 95% confidence interval: 1.21-61.92). There were three cardiac reoperations. Freedom from reintervention after ASO for patients with single sinus CA at 1 year, 5 years, and 10 years were 97.3%, 91.9%, and 91.9%, respectively. Interestingly, among all patients undergoing ASO during this time period (n = 304), single-sinus CA anatomy was not a risk factor for overall death (P = .758). Conclusions: In a high-volume cardiac program in a lower middle-income country like Vietnam, ASO can be safely performed with single sinus CA anatomy, irrespective of the presenting coronary anatomy.

Long-term follow-up after simultaneous arterial switch operation and aortic arch repair.

OBJECTIVES: Taussig-Bing anomaly (TBA) and transposition of the great arteries (TGA) with hypoplastic or interrupted aortic arch (AA) are rare anomalies. Various operative techniques and a high incidence of reinterventions are described. The aim of this retrospective single-centre study was to evaluate operative data, mortality and reintervention rate with special regard to the AA. METHODS: At the Children's Heart Center Linz, 50 patients with the above-mentioned diagnosis have been corrected by a simultaneous repair between 2001 and 2022. Thirty-seven children had TBA, 13 had TGA and 5 of them had an interrupted AA. The median age at operation was 7 [interquartile range (IQR) 5-9] days, weight 3.38 (IQR 2.9-3.8) kg and follow-up 9.3 (IQR 3.1-14.5) years. The AA reconstruction was performed without patch material in 49 cases. RESULTS: There was 1 in-hospital mortality in a TBA patient and 1 late mortality (7 years later, neuroblastoma). 14/49 patients needed at least 1 reoperation (28.6%, all TBA) and 3 further patients had catheter reintervention or radiofrequency ablation only (6.1%, 2 TBA). Seventy-five percent of these procedures affected the right heart/pulmonary arteries; there was 1 re-coarctation repair. CONCLUSIONS: The simultaneous correction of TBA and TGA with AA obstruction or interruption is a safe operation with very low mortality. The AA reconstruction with minimized use of patch material resulted in a low restenosis rate.

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.

Acute kidney injury after arterial switch operation: incidence, risk factors, clinical impact - a retrospective single-center study.

BACKGROUND: This retrospective study aimed to determine the incidence, risk factors, and outcomes of acute kidney injury (AKI) in neonates following the arterial switch operation (ASO) for transposition of great arteries (TGA). METHODS: Retrospective review of medical data of children who underwent ASO in 2019-2020 in the Ukrainian Children's Cardiac Center. RESULTS: 76 consecutive neonatal patients were included, 48 developed AKI after ASO (51.7%), and 24 - had severe AKI (25.8%). Severe AKI development was associated with longer cross-clamp time: 82 (61-127) versus 73.5 (53-136) in the non-severe AKI group (p = 0.02). 76 min of cross-clamp time were defined as a threshold value for increased severe AKI risk, OR 4.4 (95% CI: 1.5 - 13, p = 0.01). Higher lactate levels during cardiopulmonary bypass (CPB) increased severe AKI development risk, OR 1.5 (95% CI: 1.0 - 2.0, p = 0.03). Children with severe AKI had prolonged mechanical ventilation, longer time to negative fluid balance, and higher postoperative day 3 (POD3) Inotropic Score (IS). Only one patient required peritoneal dialysis. CONCLUSIONS: In our study, 51.7% of patients developed AKI after ASO, 25.8%-severe AKI. Prolonged cross-clamp time and higher lactate levels during cardiopulmonary bypass increased the risk for severe AKI development. The development of AKI was associated with prolonged mechanical ventilation, longer time to negative fluid balance, higher POD 3 Inotropic Score.

Evaluation of perfusion index and left ventricular output changes in low cardiac output syndrome after arterial switch operation.

INTRODUCTION: Transposition of great arteries is one of newborns' most common cyanotic CHDs, and its treatment is arterial switch operation in the first days of life. Low cardiac output syndrome may develop in the early postoperative period. In this study, we evaluated perfusion index and left ventricular output blood flow changes in patients who underwent arterial switch operation and developed low cardiac output syndrome. METHODS: This study was conducted prospectively in newborns with transposition of great arteries who underwent arterial switch operation between 1st August 2020 and 1st August 2022. Low cardiac output syndrome score and left ventricular output were investigated. Initially, 6th, 12th, 18th, and 24th hour perfusion index and left ventricular output values of patients with and without low cardiac output syndrome were recorded. The results were evaluated statistically. RESULTS: A total of 60 patients were included in the study. Sex distribution was equal. The median age at the time of surgery was 5 days (interquartile range 3-7 days), and the median weight was 3.1 kg (interquartile range 2.9-3. 4). Low cardiac output syndrome was detected in 30% (n = 18) of cases. The median perfusion index of patients who developed low cardiac output syndrome was significantly lower at the 12th, 18th, and 24th hours (p < 0.05) (0.99 versus 1.25, 0.86 versus 1.21, and 0.96 versus 1.33, respectively). Similarly, the median left ventricular output of patients who developed low cardiac output syndrome was significantly lower at 12th, 18th, and 24th hours (p < 0.05) (95 versus 110 ml/kg/min, 89 versus 109 ml/kg/min, and 92 versus 112 ml/kg/min, respectively). There was a significant correlation between perfusion index values and left ventricular output at all measurements (r > 0.500, p < 0.05). CONCLUSION: Perfusion index and left ventricular output measurements decreased in newborns who developed low cardiac output syndrome after arterial switch operation, especially at 12th and 18th hours. Serial perfusion index and left ventricular output measurements can be instructive in predicting low cardiac output syndrome development.

Coronary artery compression by pulmonary artery stenting after arterial switch operation: a novel indication for coronary compression test.

Pulmonary artery stenosis is one of the most common complications after arterial switch operation. Stent implantation is an effective treatment with some risks related to coronary artery compression. We present the case of a patient affected by pulmonary stenosis after arterial switch operation. Coronary compression testing demonstrated compression of the left coronary artery from the balloon inflated in the left pulmonary artery. We should systematically consider the use of coronary balloon testing before stent implantation in patients with a history of switch operation.