Long-term outcomes of the neoaorta after arterial switch operation for transposition of the great arteries

Neoaortic Regurgitation Detected by Echocardiography After Arterial Switch Operation: A Systematic Review and Meta-Analysis

Background

Neoaortic root dilatation (NeoARD) and neoaortic regurgitation (NeoAR) are common sequelae following the arterial switch operation (ASO) for transposition of the great arteries.

Objectives

The authors aimed to estimate the cumulative incidence of NeoAR, assess whether larger neoaortic root dimensions were associated with NeoAR, and evaluate factors associated with the development of NeoAR during long-term follow-up.

Methods

Electronic databases were systematically searched for articles that assessed NeoAR and NeoARD after ASO, published before November 2022. The primary outcome was NeoAR, classified based on severity categories (trace, mild, moderate, and severe). Cumulative incidence was estimated from Kaplan-Meier curves, neoaortic root dimensions using Z-scores, and risk factors were evaluated using random-effects meta-analysis.

Results

Thirty publications, comprising a total of 6,169 patients, were included in this review. Pooled estimated cumulative incidence of ≥mild NeoAR and ≥moderate NeoAR at 30-year follow-up were 67.5% and 21.4%, respectively. At last follow-up, neoaortic Z-scores were larger at the annulus (mean difference [MD]: 1.17, 95% CI: 0.52-1.82, P < 0.001; MD: 1.38, 95% CI: 0.46-2.30, P = 0.003) and root (MD: 1.83, 95% CI: 1.16-2.49, P < 0.001; MD: 1.84, 95% CI: 1.07-2.60, P < 0.001) in patients with ≥mild and ≥moderate NeoAR, respectively, compared to those without NeoAR. Risk factors for the development of any NeoAR included prior pulmonary artery banding, presence of a ventricular septal defect, aorto-pulmonary mismatch, a bicuspid pulmonary valve, and NeoAR at discharge.

Conclusions

The risks of NeoARD and NeoAR increase over time following ASO surgery. Identified risk factors for NeoAR may alert the clinician that closer follow-up is needed. (Risk factors for neoaortic valve regurgitation after arterial switch operation: a meta-analysis; CRD42022373214).

Multimodality Imaging in Management of Adults with Dextro-Transposition of the Great Arteries Post Arterial Switch Operation

•Echo is an essential tool for monitoring long-term complications of D-TGA with ASO. •Multimodality imaging is complementary to echo in the assessment of complications. •4D flow CMR can assess supravalvular PS post ASO. •Branch pulmonary arteries after LeCompte maneuver can be challenging to image.

Clinical Course of TGA After Arterial Switch Operation in the Current Era

Background

The number of patients with an arterial switch operation (ASO) for transposition of the great arteries (TGA) is steadily growing; limited information is available regarding the clinical course in the current era.

Objectives

The purpose was to describe clinical outcome late after ASO in a national cohort, including survival, rates of (re-)interventions, and clinical events.

Methods

A total of 1,061 TGA-ASO patients (median age 10.7 years [IQR: 2.0-18.2 years]) from a nationwide prospective registry with a median follow-up of 8.0 years (IQR: 5.4-8.8 years) were included. Using an analysis with age as the primary time scale, cumulative incidence of survival, (re)interventions, and clinical events were determined.

Results

At the age of 35 years, late survival was 93% (95% CI: 88%-98%). The cumulative re-intervention rate at the right ventricular outflow tract and pulmonary branches was 36% (95% CI: 31%-41%). Other cumulative re-intervention rates at 35 years were on the left ventricular outflow tract (neo-aortic root and valve) 16% (95% CI: 10%-22%), aortic arch 9% (95% CI: 5%-13%), and coronary arteries 3% (95% CI: 1%-6%). Furthermore, 11% (95% CI: 6%-16%) of the patients required electrophysiological interventions. Clinical events, including heart failure, endocarditis, and myocardial infarction occurred in 8% (95% CI: 5%-11%). Independent risk factors for any (re-)intervention were TGA morphological subtype (Taussig-Bing double outlet right ventricle [HR: 4.9, 95% CI: 2.9-8.1]) and previous pulmonary artery banding (HR: 1.6, 95% CI: 1.0-2.2).

Conclusions

TGA-ASO patients have an excellent survival. However, their clinical course is characterized by an ongoing need for (re-)interventions, especially on the right ventricular outflow tract and the left ventricular outflow tract indicating a strict lifelong surveillance, also in adulthood.

Growth of the Neo-Aortic Root and Prognosis of Transposition of the Great Arteries

BACKGROUND

Neo-aortic root dilatation can lead to significant late morbidity after the arterial switch operation (ASO) for dextro-transposition of the great arteries (d-TGA).

OBJECTIVES

We sought to examine the growth of the neo-aortic root in d-TGA.

METHODS

A single-center, retrospective cohort study of patients who underwent the ASO between July 1, 1981 and September 30, 2022 was performed. Morphology was categorized as dextro-transposition of the great arteries with intact ventricular septum (d-TGA-IVS), dextro-transposition of the great arteries with ventricular septal defect (d-TGA-VSD), and double-outlet right ventricle-transposition of the great arteries type (DORV-TGA). Echocardiographically determined diameters and derived z scores were measured at the annulus, sinus of Valsalva, and sinotubular junction immediately before the ASO and throughout follow-up. Trends in root dimensions over time were assessed using linear mixed-effects models. The association between intrinsic morphology and the composite of moderate-severe aortic regurgitation (AR) and neo-aortic valve or root intervention was evaluated with univariable and multivariable Cox proportional hazards models.

RESULTS

Of 1,359 patients who underwent the ASO, 593 (44%), 666 (49%), and 100 (7%) patients had d-TGA-IVS, d-TGA-VSD, and DORV-TGA, respectively. Each patient underwent a median of 5 echocardiograms (Q1-Q3: 3-10 echocardiograms) over a median follow-up of 8.6 years (range: 0.1-39.3 years). At 30 years, patients with DORV-TGA demonstrated greater annular (P < 0.001), sinus of Valsalva (P = 0.039), and sinotubular junction (P = 0.041) dilatation relative to patients with d-TGA-IVS. On multivariable analysis, intrinsic anatomy, older age at ASO, at least mild AR at baseline, and high-risk root dilatation were associated with moderate-severe AR and neo-aortic valve or root intervention at late follow-up (all P < 0.05).

CONCLUSIONS

Longitudinal surveillance of the neo-aortic root is warranted long after the ASO.

Persistent neo-aortic root dilatation and aortic valve insufficiency after arterial switch operation following prior pulmonary artery banding

Although there have been great improvements in the short- and medium-term outcomes of the arterial switch operation (ASO) for transposition of the great arteries (TGA), some complications including pulmonary artery stenosis, aortic valve insufficiency, and aortic root dilatation have also been reported. After ASO, the original pulmonary root and valve, which function in the systemic position as the neo-aortic root and valve respectively, are exposed to the systemic blood pressure, resulting in aortic root dilatation and valve insufficiency in some patients. One of the risk factors for these complications is a history of prior pulmonary artery banding (PAB). Complex TGA anatomy, including transposition of the great arteries and ventricular septal defect (TGA-VSD) or double outlet right ventricle and ventricular septal defect (DORV-VSD), is also an independent risk factor for neo-aortic dilatation and aortic valve regurgitation. Aortic valve and root replacement is sometime necessary for the patients with these pathologies long-term after ASO. Here, we present a patient who had persistent aortic sinus dilatation and aortic valve insufficiency since ASO and necessitating aortic root and valve replacement 15 years after ASO preceded by PAB. The patient underwent Bentall operation and his clinical course was favorable. Histological findings after root replacement revealed no remarkable structural difference between neo-aortic wall (originally pulmonary artery) and original aortic wall.

Strategies for Complex Reoperative Aortic Arch Reconstruction in Patients With Congenital Heart Disease

Aortic dilation is common in patients with congenital heart disease including those with a bicuspid aortic valve, connective tissue disease, coarctation of the aorta, and conotruncal defects. In addition, neo-aortic dilation has been described in patients after aortic reconstruction including the Norwood procedure, the arterial switch operation, and the Ross procedure. Although aortic catastrophe is rare in patients with congenital heart disease, common pathologic endpoints in these patients likely manifest with similar aortic tissue behavior. A lifelong care model with similar indications for surveillance and prophylactic repair to other more common aortopathies is therefore warranted. Still, reoperative aortic arch reconstruction in these patients is often a complex and high-risk endeavor, and in all cases, a tailored and adaptable plan ensuring adequate myocardial and cerebral protection with appropriate rescue measures is paramount. A surgical team taking on these challenging cases should possess an armamentarium of open, hybrid, and endovascular techniques which can be individualized to a patient's unique anatomy, surgical history, and concomitant lesions as well as the team's measured outcomes and experience.

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.

Paediatrician's guide to post-operative care for biventricular CHD: a review

IMPORTANCE

Paediatricians play an integral role in the lifelong care of children with CHD, many of whom will undergo cardiac surgery. There is a paucity of literature for the paediatrician regarding the post-operative care of such patients.

OBSERVATIONS

The aim of this manuscript is to summarise essential principles and pertinent lesion-specific context for the care of patients who have undergone surgery or intervention resulting in a biventricular circulation.

CONCLUSIONS AND RELEVANCE

Familiarity with common issues following cardiac surgery or intervention, as well as key details regarding specific lesions and surgeries, will aid the paediatrician in providing optimal care for these patients.

Being Overweight Is Related to Neoaortic Sinus Dilatation After Arterial Switch Operation

Background

Neoaortic sinus dilatation is a late comorbidity after an arterial switch operation in patients with dextro-transposition of the great arteries. We aim to explore whether neoaortic sinus dilatation is related to overweight or obesity, as these affect aortic remodeling in such patients.

Methods

We measured neoaortic diameters including those for the annulus, sinus, sinotubular junction, and ascending aorta by echocardiography and studied the relationship between these diameters and body mass index in patients aged 15 years and older after an arterial switch operation.

Results

A total of 45 patients were studied. Median (interquartile range) age, body mass index, and systolic blood pressure at echocardiography were 20 (17–28) years, 21.2 (18.4–24.2) kg/m2, and 120 (112–127) mm Hg, respectively. Echocardiogram revealed the following median values (interquartile ranges): neoaortic annulus diameter, 22.2 (19.8–23.8) mm; sinus diameter, 34.6 (31.8–39.8) mm; sinotubular junction diameter, 27.5 (22.4–30.0) mm; and ascending aortic diameter, 20.4 (19.4–22.7) mm. The neoaortic sinus diameter was significantly correlated with body mass index (r = 0.41, P = .004) and was significantly larger in patients with concomitant ventricular septal defect (P &lt; .001) and those who were over-weight (body mass index ≥25 kg/m2; P = .006).

Conclusion

Neoaortic sinus dilatation after an arterial switch operation is associated with being overweight during adolescence and young adulthood. It is important to prevent obesity in patients after an arterial switch operation and educate them on a healthy lifestyle.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the use of cardiovascular magnetic resonance in pediatric congenital and acquired heart disease : Endorsed by The American Heart Association

Cardiovascular magnetic resonance (CMR) has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of CMR in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of CMR in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the Use of Cardiac Magnetic Resonance in Pediatric Congenital and Acquired Heart Disease: Endorsed by The American Heart Association

Cardiovascular magnetic resonance has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of cardiovascular magnetic resonance in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of cardiovascular magnetic resonance in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Nine-Year Experience with the Arterial Switch Operation with Closed Coronary Transfer

BACKGROUND

Coronary artery transfer is a critical step of the arterial switch operation (ASO) for transposition of the great arteries (TGA). Strategies for coronary transfer include open transfer before neo-aortic anastomosis or closed transfer after neo-aortic anastomosis. This study reports outcomes of ASO with closed coronary transfer at a single institution.

METHODS

A retrospective analysis was performed of patients undergoing ASO for TGA from November 2006 to September 2015. Closed coronary transfer was universally employed. Patients were classified into simple versus complex coronary anatomy groups. The primary outcome was overall survival. Secondary outcomes included reoperation-free survival, coronary re-intervention, and aortic insufficiency.

RESULTS

Ninety-six consecutive patients underwent ASO for TGA. Median follow-up was 5.8 years. Thirty-five (36%) of patients had complex coronary anatomy, which was associated with significantly longer cardiopulmonary bypass and aortic cross-clamp time. Overall survival was 97.4%, and reoperation-free survival was 83.6%. There was no difference in survival or reoperation-free survival between patients with simple versus complex coronary anatomy. Hispanic ethnicity, side-by-side great arteries, and urgent or emergent operation were significantly associated with the composite outcome of reoperation or mortality. There were no coronary interventions after ASO, and the incidence of moderate or greater aortic insufficiency was 2.1% at hospital discharge and 1.5% in follow-up.

CONCLUSIONS

Closed coronary transfer during ASO has excellent short and mid-term results. Despite variable and often complex coronary anatomy, coronary ischemic events following ASO are avoidable. Closed coronary transfer has a low risk of aortic valve injury or insufficiency.

Neo-aortic posterior sinus of Valsalva reduction and closed coronary artery transfer as a method to approach aortopulmonary mismatch in transposition of great arteries

OBJECTIVE

In transposition of great arteries (TGA), aortopulmonary mismatch (APM) can determine postoperative neo-aortic insufficiency after arterial switch operation (ASO). The distortion of sinu-tubular junction may be the geometric mechanism responsible. We developed a strategy able to reduce the mismatch at the timing of ASO, and in this study, we aimed to describe our indications and results.

METHODS

Preoperative root circumferences at the level of the mid-portion of sinus of Valsalva and ascending aorta circumference were used to define APM. Indication to surgery was a neo-aortic root (NAR) to ascending aorta ratio ≥ 1.4. Along with standard ASO, posterior neo-aortic sinus inverted conal resection and punch technique for coronary reimplantation was used in all patients to re-establish the more geometric ratio possible between the two components. Hypoplastic aortic arch (HAA) and aortic coarctation (CA) were managed by aortic arch enlargement with an autologous pericardial patch.

RESULTS

Twenty patients (20 male), 19 with diagnoses TGA (17 with ventricular septal defect, 85%) and 1 with Taussig-Bing anomaly underwent ASO. HAA was present in three (15%) and CA in two (10%). The mean preoperative neo-aortic to ascending aorta ratio was 1.8 versus 1.1 postoperatively (p < .01). No moderate or severe neo-aortic insufficiency was observed before discharge and at a mean follow-up of 4.3 years (interquartile range = 0.5-12 years).

CONCLUSION

Neo-aortic reduction plasty with coronary reimplantation by punch technique is an effective strategy to approach preoperative APM in TGA. This technique confers a more harmonious geometry to NAR that can improve neo-aortic valve function.

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.

Management considerations in the adult with surgically modified d-transposition of the great arteries

Dextro-transposition of the great arteries (D-TGA) has undergone a significant evolution in surgical repair, leading to survivors with vastly different postsurgical anatomy which in turn guides their long-term cardiovascular morbidity and mortality. Atrial switch repair survivors are limited by a right ventricle in the systemic position, arrhythmia and atrial baffles prone to obstruction or leak. Functional assessment of the systemic right ventricle is complex, requiring multimodality imaging to include specialised echocardiography and cross-sectional imaging (MRI and CT). In the current era, most neonates undergo the arterial switch operation with increasing understanding of near-term and long-term outcomes specific to their cardiac anatomy. Long-term observations of the Lecompte manoeuvre or coronary stenoses following transfer continue, with evolving understanding to improve surveillance. Ultimately, an understanding of postsurgical anatomy, specialised imaging techniques and interventional and electrophysiological procedures is essential to comprehensive care of D-TGA survivors.

Multimodality Imaging of Transposition of the Great Arteries

Transposition of the great arteries (TGA) is a congenital conotruncal abnormality characterized by discordant connections between the ventricles and great arteries, with the aorta originating from the right ventricle (RV), and the pulmonary artery (PA) originating from the left ventricle (LV). The two main types of TGA are complete transposition or dextro-transposition of the great arteries (D-TGA), commonly referred to as d-loop, and congenitally corrected transposition (CCTGA), commonly referred to as l-loop or L-TGA. In D-TGA, the connections between the ventricles and atria are concordant, whereas in CCTGA they are discordant, with the left atrium connected to the RV, and the right atrium connected to the LV. D-TGA manifests during the neonatal period and can be surgically managed by atrial switch operation (AtrSO), arterial switch operation (ASO), Rastelli procedure, or Nikaidoh procedure. Arrhythmia, systemic ventricular dysfunction, baffle stenosis, and baffle leak are the common complications of AtrSO, whereas supravalvular pulmonary or branch PA stenosis, neoaortic dilatation, and coronary artery narrowing are the common complications of ASO. CCTGA may manifest late in life, even in adulthood. Surgeries for associated lesions such as tricuspid regurgitation, subpulmonic stenosis, and ventricular septal defect may be performed. A double-switch operation that includes both the atrial and arterial switch operations constitutes anatomic correction for CCTGA. Imaging plays an important role in the evaluation of TGA, both before and after surgery, for helping define the anatomy, quantify hemodynamics, and evaluate complications. Transthoracic echocardiography is the first-line imaging modality for presurgical planning in children with TGA. MRI provides comprehensive morphologic and functional information, particularly in adults after surgery. CT is performed when MRI is contraindicated or expected to generate artifacts. The authors review the imaging appearances of TGA, with a focus on pre- and postsurgical imaging. Online supplemental material is available for this article. ^©RSNA, 2021.

Growth Pattern of the Neo-Aorta after Arterial Switch Operation during Childhood

Background and Objectives

Neo-aortic root dilatation (ARD) and annular dilatation (AAD) tend to develop after arterial switch operation (ASO). However, the trend of neo-aortic growth has not been well established. This paper aims to identify this trend, its associated factors, and predictors of neo-aortic dilatation after ASO.

Methods

We analyzed the growth trend of the neo-aortic root, annulus, and sinotubular junction (STJ) z-scores using random coefficients model and the risk factors affecting neo-aortic dilatation in 163 patients who underwent ASO from 2006 to 2015.

Results

Among 163 patients, 41 had a ventricular septal defect, and 11 had Taussig-Bing (TB) anomaly. The median follow-up duration was 6.61 years. The increased in the neo-aortic root z-score was different between the trapdoor and non-trapdoor coronary artery transfer techniques (0.149/year, p<0.001 vs. 0.311/year, p<0.001). Moreover, the neo-aortic annulus and STJ z-score significantly increased over time after ASO (0.067/year, p<0.001; 0.309/year, p<0.001). Pulmonary artery banding (PAB) was rather a negative affecting factor. The probabilities of freedom from ARD, AAD, and neo-aortic STJ dilatation at 10 years after ASO were 33.4%, 53.9%, and 65.4%. Neo- aortic regurgitation within 1 year was the predictor of ARD, AAD, and neo-aortic STJ dilatation. TB anomaly, PAB, and native pulmonary sinus z-score were other predictors for ARD.

Conclusion

The growth of neo-aortic root, annulus, and STJ after ASO was greater than somatic growth during childhood. The coronary artery transfer technique affected the growth pattern of the neo-aortic root.

Arterial switch operation for Taussig-Bing anomaly with aortic arch obstruction

INTRODUCTION

The short-term survival rate after single-stage correction of Taussig-Bing anomaly with aortic arch obstruction remains favorable. However, some cases are encountered occasionally in which single-stage correction was not performed during the neonatal period. Accordingly, we evaluated the midterm outcomes of different surgical strategies.

METHODS

Seven patients who underwent an arterial switch operation and intraventricular rerouting as definitive surgery between 2007 and 2017 were investigated. Of these 7 patients, 3 had undergone previous pulmonary artery banding and aortic arch reconstruction.

RESULTS

The median body weight at definitive surgery was 3.3 kg (range 2.9-8.3 kg). At definitive surgery, the arrest time for single-stage correction (162.3 ± 21.7 min) was significantly shorter than that of staged repair (206.3 ± 5.1 min, p = 0.020). There was no hospital or late death. One patient in both strategy groups underwent aortic reintervention 54 months and 7.1 months after the definitive operation. Neoaortic valve (perinatal pulmonary valve) diameter decreased significantly from the perinatal valve diameter following definitive surgery (median +4.94z and +2.12z, respectively, p = 0.016) but there was no significant difference in the neopulmonary valve (perinatal aortic valve) diameter. Both single-stage correction and staged repair patients showed a similar trend. At the last follow-up, no patient had greater than mild neoaortic or neopulmonary valve regurgitation.

CONCLUSION

The surgical outcomes of both single-stage correction and staged correction for Taussig-Bing anomaly with aortic arch obstruction are excellent. Both strategies produce similar changes in the diameter and regurgitation grade of the neoaortic and neopulmonary valves.

Time course and predictors for neoaortic root dilatation and neoaortic valve regurgitation during adult life after arterial switch operation

INTRODUCTION AND OBJECTIVES

There are limited data on the long-term development of neoaortic root dilatation (NRD) and neoaortic valve regurgitation (AR) after arterial switch operation (ASO) for transposition of the great arteries during adult life.

METHODS

We performed a retrospective longitudinal analysis of 152 patients older than 15 years who underwent ASO for transposition of the great arteries and who were followed-up for 4.9±3.3 years in 2 referral centers. Sequential changes in body surface-adjusted aortic root dimensions and progression to moderate/severe AR were determined in patients with 2 or more echocardiographic examinations. Risk factors for dilatation were tested by Cox regression to identify predictors of AR progression.

RESULTS

At baseline, moderate AR was present in 9 patients (5.9%) and severe AR in 4 (2.6%), of whom 3 had required aortic valve surgery. Initially, the median neoaortic root dimension was 20.05±2.4mm/m², which increased significantly to 20.73±2.8mm/m² (P <.001) at the end of follow-up. The mean change over time was 0.14mm/m²/y (95%CI, 0.07-0.2). Progressive AR was observed in 20 patients (13.5%) and 6 patients (4%) required aortic valve surgery. Progressive AR was associated with bicuspid valve, AR at baseline, NRD at baseline, and neoaortic root enlargement. Independent predictors were bicuspid valve (HR, 3.3; 95%CI, 1.1-15.2; P=.037), AR at baseline (HR, 5.9; 95%CI, 1.6-59.2; P=.006) and increase in NRD (HR, 4.1 95%CI, 2-13.5; P=.023).

CONCLUSIONS

In adult life, NRD and AR progress over time after ASO. Predictors of progressive AR are bicuspid valve, AR at baseline, and increase in NRD.

Left Ventricular Stiffness in Adolescents and Young Adults After Arterial Switch Operation for Complete Transposition of the Great Arteries

We tested the hypothesis that left ventricular (LV) myocardial stiffness is altered in patients with transposition of great arteries (TGA) after arterial switch operation (ASO) and explored its associations with myocardial calibrated integrated backscatter (cIB) and LV myocardial deformation. Thirty-one patients and twenty-two age-matched controls were studied. LV myocardial stiffness was assessed by diastolic wall strain (DWS) and stiffness indices including (E/e)/LV end-diastolic dimension, (E/LV global longitudinal early diastolic strain rate)/LV end-diastolic volume, and (E/LV global circumferential early diastolic strain rate)/LV end-diastolic volume, where E and e are early diastolic transmitral and mitral annular velocities, respectively. LV myocardial cIB and longitudinal and circumferential myocardial deformation were determined by conventional and speckle tracking echocardiography. Patients had significantly lower DWS, higher stiffness indices, and greater myocardial cIB than controls (all p < 0.05). The LV longitudinal and circumferential systolic strain and systolic and diastolic strain rates were significantly lower in patients than controls (all p < 0.05). Greater average myocardial cIB was associated with lower DWS (r = - 0.44, p = 0.002). Worse DWS and LV stiffness indices were found to correlate with lower mitral annular systolic velocity, mitral annular late diastolic velocity, and LV longitudinal late diastolic strain rate (all p < 0.05). LV longitudinal and circumferential systolic strain and strain rate were also found to correlate with DWS (all p < 0.05). In conclusion, LV myocardial stiffening occurs in adolescents and young adults with TGA after ASO and is associated with impairment of ventricular systolic and diastolic myocardial deformation and myocardial fibrosis.

Transposition of the great arteries: Fetal pulmonary valve growth and postoperative neo-aortic root dilatation

Objectives

Documentation of semilunar valve growth in fetal transposition of the great arteries (TGA) and the relationship between neo‐aortic root (NAoR) dilatation, a cause for postoperative reinterventions after the arterial switch operation (ASO), and pulmonary valve (PV) annulus dimensions prenatally.

Methods

This retrospective multicenter observational study included TGA fetuses suitable for ASO. Semilunar valve annuli pre‐ASO and NAoR diameters (post‐ASO) were measured. Trends in annulus diameters were analyzed using a linear mixed‐effects model and compared with normal values. Prenatal semilunar valve Z‐scores were correlated with NAoR diameters post‐ASO.

Results

We included 137 TGA fetuses (35.8% with significant ventricular septal defects [VSDs]). One hundred twenty‐one underwent ASO. Fetal TGA‐PV diameters were significantly larger than control aortic valve (AoV) and PV annuli from 23 and 27 weeks, respectively, especially when a VSD was present. Fetal TGA‐AoV annuli were significantly larger than control AoV and PV annuli from 26 and 30 weeks, respectively.

Z‐scores of fetal TGA‐PV and NAoR diameter at last follow‐up correlated significantly (P < .001 at 26‐30 wk).

Conclusion

Fetal TGA semilunar valve annuli are larger than control annuli, especially when there is a significant VSD. Factors besides postoperative hemodynamics, including fetal anatomy, PV Z‐score, prenatal flow, connective tissue properties, and genetics, may influence the risk for late reintervention in these fetuses.

The coronary reimplantation after neoaortic reconstruction technique can make a difference in arterial switch operation

BACKGROUND

The aim of this study was to determine if there was a difference between coronary reimplantation after neoaortic reconstruction and open coronary reimplantation technique in arterial switch operation (ASO).

METHODS

A total of 236 patients who underwent ASO from March 1994 to August 2018 were enrolled in this study. Multivariate analysis was performed for postoperative early mortality. Patients were divided into the open coronary reimplantation and coronary reimplantation after neoaortic reconstruction groups. The 30-day mortality, intraoperative and postoperative coronary artery (CA) revisions, CA-related late morbidity and mortality, and early and late neoaortic valve regurgitations after ASO were compared between the two groups.

RESULTS

Overall postoperative early mortality was 7.2% (17/236). Patients who underwent open coronary reimplantation had higher early mortality as compared with those who underwent coronary reimplantation after neoaortic reconstruction. Risk factors for postoperative early mortality from multivariate analysis were cardiopulmonary bypass time and open coronary reimplantation. There was a higher incidence of CA-related late mortality or morbidity in the open coronary reimplantation group. The open coronary reimplantation group had a higher incidence of intraoperative or postoperative CA revision. There were no differences in the incidence of mild or more neoaortic valve regurgitation at discharge or in the 5-year freedom from mild or more neoaortic valve regurgitation.

CONCLUSIONS

CA reimplantation after neoaortic reconstruction yields better results in mortality and intraoperative or postoperative CA-related problems in ASO without increasing postoperative neoaortic valve regurgitation.

Management of the Adult with Arterial Switch

Dextro-transposition of the great arteries (d-TGA) is a lethal congenital heart defect in which the great arteries-the pulmonary artery and aorta-are transposed to create ventriculoarterial discordance. Corrective surgical interventions have resulted in significant improvements in morbidity and mortality for this once-fatal congenital heart defect. The initial palliative surgery for d-TGA was the atrial switch operation, which provided physiological correction. The Mustard and Senning "atrial switch" procedures, in which an atrial baffle is created to produce a discordant atrioventricular connection on the existing discordant ventriculoarterial connection, showed preliminary success for the correction of d-TGA. However, follow-up evaluations demonstrated increasing complications from the right ventricle utilized as a systemic ventricle, resulting in progressive right ventricular dysfunction. Thus, the search continued for an anatomical correction of d-TGA to return the great arteries to their normal ventricular connections. The arterial switch operation (ASO), though attempted and theorized by many, was first successfully performed by Dr. Jatene and colleagues in 1975. For ASO, the distal main pulmonary artery and the distal ascending aorta are transected and then anastomosed to their respective ventricles with relocation of the coronary arteries to the neoaorta. The ASO has replaced the atrial switch operation since the 1980s and is now the standard surgical correction for d-TGA. As more patients who have undergone ASO are living into adulthood, late complications of this procedure have become more evident. The most common late postoperative complications include coronary artery stenosis, neoaortic root dilation, neoaortic insufficiency, and neopulmonic stenosis. Adults who have undergone ASO in childhood will need follow-up with surveillance imaging and evaluation of new symptoms or declining function to prevent and manage late postoperative complications. This review describes the management strategies for common late complications in patients who have undergone ASO.

Progression of aortic root dilatation and aortic valve regurgitation after the arterial switch operation

Objective

To study neo-aortic growth and the evolution of neo-aortic valve regurgitation (AR) in patients with transposition of the great arteries (TGA) after arterial switch operation (ASO) from newborn to adulthood and to identify patients at risk.

Methods

Neo-aortic dimensions (annulus/root/sinotubular junction) and neo-aortic valve regurgitation were assessed serially in 345 patients with TGA who underwent ASO between 1977 and 2015. Linear mixed-effect models were used to assess increase of neo-aortic dimensions over time and to identify risk factors for dilatation. Risk factor analysis for AR by using time-dependent Cox regression models.

Results

After a rapid increase in the first year after ASO and proportional growth in childhood, neo-aortic dimensions continue to increase in adulthood without stabilisation. Annual diameter increase in adulthood was 0.39±0.06, 0.63±0.09 and 0.54±0.11 mm for, respectively, neo-aortic annulus, root and sinotubular junction, all significantly exceeding normal growth. AR continues to develop over time: freedom from AR ≥moderate during the first 25 years post-ASO was 69%. Risk factors for root dilatation were complex TGA anatomy (TGA-ventricular septal defect (VSD), double outlet right ventricle with subpulmonary VSD) and male gender. Risk factors for AR ≥moderate were: complex TGA anatomy and neo-aortic growth. Per millimetre increase in aortic root dimension, there was a 9% increase in the hazard of AR ≥moderate. Bicuspid pulmonary valve did not relate to the presence of root dilatation or AR.

Conclusion

After ASO, neo-aortic dilatation proceeds beyond childhood and is associated with an increase in AR incidence over time. Careful follow-up of the neo-aortic valve and root function is mandatory, especially in males and in patients with complex TGA anatomy.

Validation of aortic valve 4D flow analysis and myocardial deformation by cardiovascular magnetic resonance in patients after the arterial switch operation

BACKGROUND

Aortic regurgitation (AR) and subclinical left ventricular (LV) dysfunction expressed by myocardial deformation imaging are common in patients with transposition of the great arteries after the arterial switch operation (ASO). Echocardiographic evaluation is often hampered by reduced acoustic window settings. Cardiovascular magnetic resonance (CMR) imaging provides a robust alternative as it allows for comprehensive assessment of degree of AR and LV function. The purpose of this study is to validate CMR based 4-dimensional flow quantification (4D flow) for degree of AR and feature tracking strain measurements for LV deformation assessment in ASO patients.

METHODS

A total of 81 ASO patients (median 20.6 years, IQR 13.5-28.4) underwent CMR for 4D and 2D flow analysis. CMR global longitudinal strain (GLS) feature tracking was compared to echocardiographic (echo) speckle tracking. Agreements between and within tests were expressed as intra-class correlation coefficients (ICC).

RESULTS

Eleven ASO patients (13.6%) showed AR > 5% by 4D flow, with good correlation to 2D flow assessment (ICC = 0.85). 4D flow stroke volume of the aortic valve demonstrated good agreement to 2D stroke volume over the mitral valve (internal validation, ICC = 0.85) and multi-slice planimetric LV stroke volume (external validation, ICC = 0.95). 2D flow stroke volume showed slightly less, though still good agreement with 4D flow (ICC = 0.78) and planimetric LV stroke volume (ICC = 0.87). GLS by CMR was normal (- 18.8 ± 4.4%) and demonstrated good agreement with GLS and segmental analysis by echocardiographic speckle tracking (GLS = - 17.3 ± 3.1%, ICC of 0.80).

CONCLUSIONS

Aortic 4D flow and CMR feature tracking GLS analysis demonstrate good to excellent agreement with 2D flow assessment and echocardiographic speckle tracking, respectively, and can therefore reliably be used for an integrated and comprehensive CMR analysis of aortic valve competence and LV deformation analysis in ASO patients.

Utility of Follow-Up Annual Echocardiograms in Patients With Complete Transposition of the Great Arteries After Arterial Switch Operations

The arterial switch operation (ASO) in complete transposition of the great arteries (TGA) has increased long-term survival. Annual follow-up echocardiograms are recommended, but evidence-based guidelines do not exist. We sought to assess how often a patient with TGA after ASO who had no symptoms or change in physical exam underwent an intervention based solely on echocardiographic changes. We retrospectively reviewed all records from patients with TGA and a history of ASO followed at our institution between November 1983 and January 2015. Changes in echocardiograms resulting in hospital admission, significant medication change, interventional catheterization, or surgical procedure were identified through the surgical and cardiac catheterization laboratory databases and patient charts. These changes were referred to as an actionable change (AC). Interventions were defined as being driven by either clinical (change in physical exam, patient and/or parental concerns) or echocardiographic findings. A total of 1,792 echocardiograms from 149 patients were reviewed. Median number of echocardiograms per patient was 12 (1 to 34). Of the 1,792 echocardiograms, 20 (1.12%) were associated with AC. The most common intervention for an AC was cardiac catheterization (13 of 20, 65%). Most AC (15 of 20, 75%) occurred in the first decade after ASO. AC occurred in 83% (5 of 6) of those with a history of both ASO and arch repair. Annual echocardiograms in patients with TGA after ASO are rarely useful and are unnecessary. In conclusion, decreasing surveillance of asymptomatic patients to biennial follow-up echocardiograms in asymptomatic patients without physical examination changes is safe and would decrease medical expenses.

Long-term Management of the Arterial Switch Patient

PURPOSE OF REVIEW

This review paper describes the management of patients with dextro-transposition of the great arteries (D-TGA) with a focus on the complications seen and the appropriate care required to identify and prevent adverse events.

RECENT FINDINGS

D-TGA is a form of cyanotic congenital heart disease (CHD) representing ~ 3% of all CHD and almost 20% of all cyanotic CHD. Since the late 1980s, standard of care is to repair these patients with an arterial switch operation (ASO) as opposed to a Mustard/Senning operation. The long-term survival and complication rates are superior in the ASO. Long-term follow-up is recommended for all D-TGA patients and includes management with adult congenital heart disease specialists and the use of echocardiography and advanced imaging with CT or MRI. The most common complications seen are pulmonary stenosis, coronary artery stenosis, and neo-aortic regurgitation. Careful evaluation of new symptoms or declining function is essential in preventing and treating these long-term sequelae.

Early and mid-term follow-up of patients receiving arterial switch operation: a single-center experience

Background

The arterial switch operation (ASO) has become the preferred method for surgical correction of transposition of the great arteries (TGA) and Taussig-Bing anomaly. This study was aimed to analysis the early and mid-term results of patients receiving ASO for TGA and Taussig-Bing anomaly in our institute.

Methods

A single-institution retrospective study was conducted to assess cardiovascular outcomes after ASO between January 2007 and December 2013. A total of 119 consecutive patients were included in this study. The median age at operation was 30 days (range, 1 day-8 years), the median weight was 3.8 kg (range, 2.0-23.0 kg). The ventricular septum was intact in 59 (49.6%) patients, 43 (36.1%) had ventricular septal defect, and 17 (14.3%) had a Taussig-Bing anomaly. We followed up patients with echocardiography. Special attention had been paid to the neo-aortic regurgitation and pulmonary stenosis.

Results

In hospital deaths occurred in 10 (8.4%) patients. The most cause of death was low cardiac output due to deconditioning of the left ventricle and myocardial infarction. Echocardiographic data after ASO were collected in 93 (85.3%) patients at a mean duration of 60.7±20.2 months. Among them, 4 (4.3%) patients had moderate to severe neo-aortic regurgitation, 1 (1.1%) patient had moderate tricuspid regurgitation, 4 (4.3%) patients had moderate pulmonary regurgitation; 1 (1.1%) patients had moderate pulmonary stenosis and no patients had severe stenosis. Only two patients required a surgical reintervention.

Conclusions

The early mortality rate has decreased and the most cause of death was low cardiac output. The outcomes of the ASO using our reconstruction and reimplantation techniques were excellent and the reoperation rate was very low in the early and mid-term follow-up.

A Quarter-Century After Primary Direct Arterial Switch Operation: Four-D-Flow MRI Video Imaging of Blood Flow Dynamics Outcomes

Four-dimensional (4-D) flow magnetic resonance imaging (MRI) examination was performed 25 years after a neonatal direct arterial switch operation for simple transposition of the great arteries. The 4-D flow MRI video shows physiological spiral anatomical configuration and laminar streamlines in the great arteries.

Left-Sided Reoperations After Arterial Switch Operation: A European Multicenter Study

BACKGROUND

We sought to report the frequency, types, and outcomes of left-sided reoperations (LSRs) after an arterial switch operation (ASO) for patients with D-transposition of the great arteries (D-TGA) and double-outlet right ventricle (DORV) TGA-type.

METHODS

Seventeen centers belonging to the European Congenital Heart Surgeons Association (ECHSA) contributed to data collection. We included 111 patients who underwent LSRs after 7,951 ASOs (1.4%) between January 1975 and December 2010. Original diagnoses included D-TGA (n = 99) and DORV TGA-type (n = 12). Main indications for LSR were neoaortic valve insufficiency (n = 52 [47%]) and coronary artery problems (CAPs) (n = 21 [19%]).

RESULTS

Median age at reoperation was 8.2 years (interquartile range [IQR], 2.9-14 years). Seven patients died early after LSRs (6.3%); 4 patients with D-TGA (5.9%) and 3 patients with DORV TGA-type (25%) (p = 0.02). Median age at last follow-up was 16.1 years (IQR, 9.9-21.8 years). Seventeen patients (16%) required another reoperation, which was more frequent in patients with DORV- TGA type (4 of 9 [45%]) than in patients with D-TGA (13 of 95 [14%]). Late death occurred in 4 patients (4 of 104 [3.8%]). The majority of survivors were asymptomatic at last clinical examination (84 of 100 [84%]).

CONCLUSIONS

Reoperations for residual LSRs are infrequent but may become necessary late after an ASO, predominantly for neoaortic valve insufficiency and CAPs. Risk at reoperation is not negligible, and DORV TGA-type anatomy, as well as procedures on the coronary arteries, were significantly associated with a higher morbidity and a lower overall survival. Recurrent reoperations after LSRs may be required.

Long-term outcomes of the arterial switch operation for transposition of the great arteries and ventricular septal defect and/or aortic arch obstruction

OBJECTIVES

Long-term outcomes after the arterial switch operation (ASO) for complex transposition of the great arteries (TGA) should be clarified.

METHODS

A retrospective study was conducted in patients operated on between 1982 and 1998. Overall 220 postoperative survivors, 79.1% with a ventricular septal defect, 13.2% with multiple ventricular septal defects, and 29.1% with aortic arch obstruction, were followed for 17 years (0-28 years).

RESULTS

The conditional survival rate was 96.7% [95% confidence interval (CI): 94.4-99.1] at 25 years. Late sudden death occurred in 2 asymptomatic patients. The cumulative incidence rate of death or reinterventions was 3.8% (95% CI: 2.9-4.8) at 25 years, with age at ASO <10 days and aortic regurgitation at discharge identified as independent risk factors. The cumulative incidence rate of neoaortic regurgitation was 41.6% (95% CI: 20.5-62.8) at 25 years with an aorto-pulmonary diameter mismatch at the time of the ASO, age at ASO <10 days and aortic regurgitation at discharge identified as independent risk factors. At the last follow-up, 53 patients (24.1%) had neoaortic root dilatation with an aortic sinus z-score ≥3 and 6 of them had a Bentall operation at a median delay of 14.1 years since the ASO. The only independent factors for neoaortic root dilatation were male sex and an aorto-pulmonary diameter mismatch at the time of the ASO.

CONCLUSIONS

Despite a continual rate of reinterventions, long-term survival and cardiovascular outcome are excellent after ASO for complex TGA. Dilatation of the neoaortic root and neoaortic regurgitation may be observed with time and 2 late sudden deaths occurred, justifying a close follow-up in all patients.

Is the Lecompte technique the last word on transposition of the great arteries repair for all patients? A magnetic resonance imaging study including a spiral technique two decades postoperatively

OBJECTIVES

To compare the Lecompte technique and the spiral anastomosis (complete anatomic correction) two decades after arterial switch operation (ASO).

METHODS

Nine patients after primary ASO with Lecompte and 6 selected patients after spiral anastomosis were evaluated 20.8 ± 2.1 years after ASO versus matched controls. Blood flow dynamics and flow profiles (e.g. vorticity, helicity) in the great arteries were quantified from time-resolved 3D magnetic resonance imaging (MRI) phase contrast flow measurements (4D flow MR) in addition to a comprehensive anatomical and functional cardiovascular MRI analysis.

RESULTS

Compared with spiral reconstruction, patients with Lecompte showed more vortex formation, supranatural helical blood flow (relative helicity in aorta: 0.036 vs 0.089; P < 0.01), a reduced indexed cross-sectional area of the left pulmonary artery (155 vs 85 mm²/m²; P < 0.001) and more semilunar valve dysfunctions (n = 5 vs 1). There was no difference in elastic aortic wall properties, ventricular function, myocardial perfusion and myocardial fibrosis between the two groups. Cross-sectional area of the aortic sinus was larger in patients than in controls (669 vs 411 mm²/m²; P < 0.01). In the spiral group, the pulmonary root was rotated after ASO more towards the normal left position (P < 0.01).

CONCLUSIONS

In this study, selected patients with spiral anastomoses showed, two decades after ASO, better physiologically adapted blood flow dynamics, and attained a closer to normal anatomical position of their great arteries, as well as less valve dysfunction. Considering the limitations related to the small number of patients and the novel MRI imaging techniques, these data may provoke reconsidering the optimal surgical approaches to transposition of the great arteries repair.

Pulmonary Artery Aneurysm Compressing the Tracheobronchial Tree Following an Arterial Switch Operation

A neonate developed severe dyspnea following an arterial switch operation due to compression of the trachea and left main bronchus by a dilated pulmonary artery. This was relieved by a second procedure in which the dilated pulmonary artery was excised and reconstructed with bovine pericardium.

Surgical Considerations in d-Transposition of the Great Arteries

The surgical treatment for d-transposition has evolved dramatically since the inception of cardiac surgery in the 1950s. Today, the arterial switch operation is employed almost exclusively in the management of this disease unless significant left ventricular outflow obstruction is present. Surgical options for these patents are reviewed and an in-depth technical discussion of arterial switch for d-transposition of the great arteries/intact ventricular septum follows.

D-transposition of the great arteries: the current era of the arterial switch operation

This paper aims to update clinicians on "hot topics" in the management of patients with D-loop transposition of the great arteries (D-TGA) in the current surgical era. The arterial switch operation (ASO) has replaced atrial switch procedures for D-TGA, and 90% of patients now reach adulthood. The Adult Congenital and Pediatric Cardiology Council of the American College of Cardiology assembled a team of experts to summarize current knowledge on genetics, pre-natal diagnosis, surgical timing, balloon atrial septostomy, prostaglandin E1 therapy, intraoperative techniques, imaging, coronary obstruction, arrhythmias, sudden death, neoaortic regurgitation and dilation, neurodevelopmental (ND) issues, and lifelong care of D-TGA patients. In simple D-TGA: 1) familial recurrence risk is low; 2) children diagnosed pre-natally have improved cognitive skills compared with those diagnosed post-natally; 3) echocardiography helps to identify risk factors; 4) routine use of BAS and prostaglandin E1 may not be indicated in all cases; 5) early ASO improves outcomes and reduces costs with a low mortality; 6) single or intramural coronary arteries remain risk factors; 7) post-ASO arrhythmias and cardiac dysfunction should raise suspicion of coronary insufficiency; 8) coronary insufficiency and arrhythmias are rare but are associated with sudden death; 9) early- and late-onset ND abnormalities are common; 10) aortic regurgitation and aortic root dilation are well tolerated; and 11) the aging ASO patient may benefit from "exercise-prescription" rather than restriction. Significant strides have been made in understanding risk factors for cardiac, ND, and other important clinical outcomes after ASO.

Valve-sparing reimplantation technique for treatment of neoaortic root dilatation late after the arterial switch operation: raising the bar

Neoaortic root dilatation can develop during long-term follow-up after an arterial switch operation (ASO). Although few patients require surgical reintervention, significant valve regurgitation is still an important cause of late morbidity. We report on a 15-year-old boy with significant dilatation of the neoaortic root that was treated with the valve-sparing reimplantation technique. There is only one reported case of valve-preserving surgery late after the ASO. Valve preservation is believed to be superior to valve replacement in patients with aortic regurgitation due to better hemodynamic performance and avoidance of anticoagulation therapy.