Late Complications Following the Arterial Switch Operation

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 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.

Outcomes after corrective surgery for congenital dextro-transposition of the arteries using the arterial switch technique: a scoping systematic review

BACKGROUND

Dextro-transposition of the great arteries (D-TGA) is the most frequent cyanotic congenital heart pathology in neonates. Surgical correction of this condition is possible using the arterial switch operation (ASO) which was first performed by Jatene in 1975.

OBJECTIVES

The aim of this study was to summarise the evidence on short- (less than 1 year), medium- (1-20 years), and long-term (more than 20 years) outcomes of children with D-TGA treated with the ASO. The primary outcome was survival. Secondary outcomes were freedom from cardiac reoperations, occurrence of aortic insufficiency, pulmonary stenosis, coronary artery anomalies, neuropsychological development problems and quality of life.

METHODS

We searched MEDLINE, EMBASE, CINAHL, LILACS, and reference lists of included articles for studies reporting outcomes after ASO for D-TGA. Screening, data extraction and risk of bias assessment were done independently by two reviewers. We pooled data using a random-effects meta-analysis of proportions and, where not possible, outcomes were synthesized narratively. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to assess the certainty of the evidence for each outcome.

MAIN RESULTS

Following ASO for TGA, short-term survival was 92.0% (95% CI 91.0-93.0%; I² = 85.8%, 151 studies, 30,186 participants; moderate certainty evidence). Medium-term survival was 90.0% (95% CI 89.0-91.0%; I² = 84.3%, 133 studies; 23,686 participants, moderate certainty evidence), while long-term survival was 87.0% (95% CI 80.0-92.0 %; I² = 84.5%, 4 studies, 933 participants, very low certainty evidence). Evaluation of the different secondary outcomes also showed satisfactory results in the short, medium and long term. Subgroup analysis suggests slightly higher survival following ASO for TGA in the second surgical era (1998 to 2018) than in the first surgical era (1975 to 1997) in the short and medium term [93.0% (95% CI 92.0-94.0) vs 90.0% (95% CI 89.0-92.0) and 93.0% (95% CI 91.0-94.0) vs 88.0% (87.0-90.0%) respectively] but not in the long term [81.0% (95% CI 76.0-86.0%) vs 89.0% (80.0-95.0%)].

CONCLUSIONS

Pooled data from many sources suggests that the ASO for D-TGA leads to high rates of survival in the short, medium, and long term.

Pregnancy Outcomes in Women With Transposition of the Great Arteries After an Arterial Switch Operation

Importance

A growing number of women are approaching childbearing age after arterial switch surgery for transposition of the great arteries. Prepregnancy counseling requires updated knowledge of the additional cardiovascular risks pregnancy poses for this cohort of women and the potential effect on their offspring; however, to our knowledge, this information is currently unknown.

Objective

To determine the pregnancy outcomes of women with transposition of the great arteries after an arterial switch operation, as well as the outcomes of their offspring.

Design, Setting, and Participants

This cohort study assessed women who had had arterial switch surgery from 1985 to the present and who were 16 years or older as of January 2018. All women with a previous arterial switch surgery for transposition of the great arteries with completed or ongoing pregnancy were included. Data were collected in a level 1 congenital cardiology center and joint obstetrics-cardiology clinic in Birmingham, United Kingdom.

Exposures

Patients were assessed before, during, and after pregnancy.

Main Outcomes and Measures

Adverse maternal cardiac events (arrhythmia, heart failure, aortic dissection, or acute coronary syndrome) and aortic root dilatation, aortic regurgitation, and left ventricular function before and after pregnancy were the main outcomes. Mode of delivery and fetal outcomes were considered secondary outcomes.

Results

A total of 25 pregnancies were identified in 15 women; 8 women had had 1 pregnancy, while 7 were multiparous. There were no adverse maternal cardiac events. Before pregnancy, 8 women (53%) had no aortic regurgitation, 1 (7%) had a trivial degree of regurgitation, 4 (26%) had mild regurgitation, and 2 (14%) had moderate regurgitation. After pregnancies, 1 woman (7%) had minor progression of aortic regurgitation. Five women (36%) had mild neoaortic root dilatation prepregnancy, but none developed progressive dilatation in the first year post-partum. A total of 24 pregnancies were completed by the end of the study, with all infants born alive and well. Nineteen modes of delivery were known; there were 7 cesarean deliveries (37%), of which 2 (11%) were recommended for aortic dilatation and 5 (26%) for obstetric indications or maternal choice.

Conclusions and Relevance

Pregnancy is well tolerated after arterial switch operation; no adverse maternal cardiac events or early progression of neoaortic root dilatation or aortic regurgitation were observed in this study. These results provide evidence to allow reassurance of women with previous arterial switch surgery who are planning pregnancies.

Late complication of intramural coronary transfer during the arterial switch operation

Intramural coronary arteries remain a major risk factor and technical challenge of the arterial switch operation for transposition of the great arteries. We report a 27-year-old woman who presented with acute coronary syndrome late after arterial switch with a complex coronary pattern (intramural left and right coronary from sinus 2). Computed tomography demonstrated that the pericardial 'saddle bag' used to reconstruct the intramural coronary was compressed between the neoaortic root and the neopulmonary trunk. During surgery, the coronary system was laid open into the neoaorta with patch enlargement, and the patient made an uneventful recovery.

Usefulness of Routine Coronary CT Angiography in Patients with Transposition of the Great Arteries After an Arterial Switch Operation

Coronary complications in patients with transposition of the great arteries (TGA) after an arterial switch operation (ASO) are relatively rare, but of all the possible postoperative adverse events, they are potentially the most dangerous. The fate of the coronary arteries, which are transplanted during the neonatal ASO, remains uncertain. There is also no consensus regarding their postoperative evaluation, especially in asymptomatic patients. The aim of this study was to present the early results of routinely performed coronary computed tomography angiography (CCTA) in asymptomatic adolescents and young adults with TGA after an ASO. An initial series of 50 CCTAs performed in asymptomatic patients with TGA after an ASO were evaluated. In each case, a detailed examination of the coronary anatomy, its relationship to the surrounding structures, its exact position in the neoaortic sinus, and the presence of significant coronary abnormalities was performed. The CT scans revealed significant coronary abnormalities in 12 asymptomatic patients: three had acute proximal angulation and stenosis, four had an intra-arterial course, seven had a muscular bridge, one had a left anterior descending artery with an intramuscular course, and one had coronary fistulas to the pulmonary arteries. Additionally, in 25 patients, proximal acute angulation of at least one coronary artery was detected, and four of them had a high ellipticity index. Most of the potentially severe anatomical features were related to the left coronary artery or the left anterior descending artery. CCTA routinely performed on asymptomatic patients with TGA after an ASO provides accurate and useful information for postoperative management. The frequency of coronary anomalies and potentially dangerous anatomical features in this group of patients is high, and their impact on postoperative follow-up remains unknown.

Coronary Artery Anomalies in Patients With Transposition of the Great Arteries and Their Impact on Postoperative Outcomes

BACKGROUND

Coronary anomalies are frequently present in children with transposition of the great arteries (TGA). Such anomalies significantly increase the complexity of arterial switch operations and may have an effect on postoperative outcomes. In this study, we aimed to assess the frequency of coronary anomalies in children with TGA and describe their effect on postoperative outcomes.

METHODS

All patients with TGA who underwent an arterial switch operation between 1991 and 2015 were consecutively enrolled in this study. Patient coronary patterns were obtained from corresponding operative reports and analyzed to determine their associations with adverse postoperative outcomes.

RESULTS

The study included 715 patients with isolated and complex TGA. Coronary anomalies were present in 33.7% of patients and were significantly correlated with the side-by-side configuration of the great arteries. Coronary sinuses with more than 1 ostium were associated with a significantly increased risk of postoperative death (hazard ratio [HR], 2.58), and coronary arteries with a single ostium were associated with an increased risk of postoperative reinterventions (HR, 2.49). In contrast, the trap-door technique of coronary artery transplantation was associated with a reduced risk of reinterventions during postoperative follow-up (HR, 0.40). Complex coronary anomalies were significantly associated with postoperative coronary events (HR, 2.12).

CONCLUSIONS

With the exception of patients whose circumflex artery branches off of the right coronary artery, an anomaly that clearly has no effect on postoperative follow-up, patients with unusual coronary patterns are at higher risk for adverse postoperative outcomes than patients with normal coronary anatomy and must be monitored carefully.

Transposition of Great Arteries with Complex Coronary Artery Variants: Time-Related Events Following Arterial Switch Operation

Coronary artery anatomy represents a challenging and, often, determining predictor of outcome in an arterial switch operation (ASO). Impact of specific coronary artery variants, such as single, intramural and inverted, on time-related events following ASO, is, yet, to be determined. We sought to compare early and late outcomes within the group of nonstandard coronary artery variants. Patients who underwent ASO from January 1995 to October 2010 were reviewed. Patients with coronary artery variants other than L1Cx1R2 ("standard" by Leiden classification) were included. Patients with single, intramural and inverted coronary artery variants incorporated in group A. All other nonstandard coronary variants incorporated in group B. Demographics, perioperative variables, early and late outcomes were assessed. Of the 123 ASO, 24 patients (19.5%) with nonstandard coronary variant were studied. Thirteen were in group A and 11 in group B. There were two early deaths (1 in group A and 1 in group B) (p > 0.05). There is one death early after hospital discharge (group A). Mean follow-up was 59.4 ± 55.1 months. There was no structural coronary artery failure after hospital discharge following ASO. Freedom from any reintervention at 8 years was (78.3 ± 9.6%) (p 0.55) with no late neo-aortic or mitral valve intervention. ASO with single, intramural or inverted coronary artery course carries no added longitudinal risk for structural or flow impairment within the group of nonstandard coronary artery variants. There is an early hazard period with no late survival attrition. Aortic arch repair as part of staged strategy prior to ASO might influence early and late outcome.

Abnormal mitral valve anatomy in d-transposition of the great arteries: anatomic characterization and surgical outcomes

Mitral valve anomalies can occur with S,D,D-transposition of the great arteries (d-TGA). Their influence on surgical technique and outcome after an arterial switch operation (ASO) has not been well described. Patients with d-TGA who underwent ASO from February 1990 to January 2011 were identified. Echocardiograms, operative reports, hospital course, and latest follow-up evaluation were reviewed. A total of 218 infants underwent ASO at a median age of 15.8 days. Survival was 95 % during a mean follow-up period of 60 months. Nine patients (4 %) were found to have similar mitral valve anomalies including anterior malalignment conoventricular septal defect, anterior displacement of the mitral valve toward the left ventricular outflow tract (LVOT), malpositioning of the posteromedial papillary muscle, unusual rotation of the mitral valve leaflets orienting the commissure toward the anterior ventricular septum, and redundant mitral valve tissue extending into the LVOT. Coarctation was more frequent in this subgroup (33 vs. 10 %; p = 0.05). Preoperative echocardiography consistently indicated suspicion of a cleft mitral valve with chordal attachments to the ventricular septum causing potential LVOT obstruction. Operative inspection did not identify a cleft or anomalous attachments in any patient, and no valvuloplasty or chordal manipulation was performed. The average hospital length of stay were similar (30.7 vs. 25.3 days; p = 0.54). One patient died late due to progressive LVOT obstruction, and one required heart transplantation. No patient had significant mitral valve regurgitation. We conclude that mitral valve anomalies associated with d-TGA are rare but present with consistent anatomic features and higher risk of coarctation. Unusual mitral valve apparatus positioning and chordal redundancy can suggest the need for valvuloplasty and chordal resection preoperatively, but this is rarely needed.

Past, present, and future of the arterial switch operation: historical review

The arterial switch operation is the extant surgical correction after a long series of palliations attempted and/or successfully achieved for the treatment of discordant ventriculoarterial connections. As early as 1954, pioneers such as Mustard, Bailey, Kay, and Idriss led the way with at first disheartening failures, temporarily leading to abandoning the procedure. The first successful atrial baffle procedure in 1958 established itself as the procedure of choice for treating discordant ventriculoarterial connections, but tenacity, courage, and vision to pursue anatomic correction finally led to the first successful arterial switch in 1975 by Jatene. After a decade to perfect surgical technique and timing indications for the various anatomic subtypes, the new era of the neonatal arterial switch since the late 1980s set the very high standards that we all know and expect today. Despite excellent early and long-term survival, important residual lesions are increasingly being recognised. Expected anatomic residuals include supravalvar pulmonary stenosis, neoaortic valve insufficiency, and coronary ostial stenosis. Reinterventions and rare, but challenging surgical reoperations address these residual findings with satisfactory outcomes. Quality of life into young adulthood is satisfactory, but functional problems include reduced exercise capacity, diffuse coronary insufficiency, and neurodevelopmental shortcomings, of which the true incidence and potential clinical implications are still unknown. The arterial switch is a spectacular anatomic correction for a once lethal condition and currently the best surgical solution for patients with discordant ventriculoarterial connections. It is, however, far from a true cure; closer and ongoing follow-up for future care will continue to be required.