Prevalence and predictors of neoaortic regurgitation after arterial switch operation for transposition of the great arteries

Pathogenesis and Surgical Treatment of Dextro-Transposition of the Great Arteries (D-TGA): Part II

Dextro-transposition of the great arteries (D-TGA) is the second most common cyanotic heart disease, accounting for 5-7% of all congenital heart defects (CHDs). It is characterized by ventriculoarterial (VA) connection discordance, atrioventricular (AV) concordance, and a parallel relationship with D-TGA. As a result, the pulmonary and systemic circulations are separated [the morphological right ventricle (RV) is connected to the aorta and the morphological left ventricle (LV) is connected to the pulmonary artery]. This anomaly is included in the group of developmental disorders of embryonic heart conotruncal irregularities, and their pathogenesis is multifactorial. The anomaly's development is influenced by genetic, epigenetic, and environmental factors. It can occur either as an isolated anomaly, or in association with other cardiac defects. The typical concomitant cardiac anomalies that may occur in patients with D-TGA include ventriculoseptal defects, patent ductus arteriosus, left ventricular outflow tract obstruction (LVOTO), mitral and tricuspid valve abnormalities, and coronary artery variations. Correction of the defect during infancy is the preferred treatment for D-TGA. Balloon atrial septostomy (BAS) is necessary prior to the operation. The recommended surgical correction methods include arterial switch operation (ASO) and atrial switch operation (AtrSR), as well as the Rastelli and Nikaidoh procedures. The most common postoperative complications include coronary artery stenosis, neoaortic root dilation, neoaortic insufficiency and neopulmonic stenosis, right ventricular (RV) outflow tract obstruction (RVOTO), left ventricular (LV) dysfunction, arrhythmias, and heart failure. Early diagnosis and treatment of D-TGA is paramount to the prognosis of the patient. Improved surgical techniques have made it possible for patients with D-TGA to survive into adulthood.

Pulmonary, aorta, and coronary arteries post-arterial switch in transposition of great arteries: intermediate-term surveillance utilizing conventional echocardiography and cardiac multislice computed tomography

BACKGROUND

Arterial switch operation (ASO) is the standard surgical choice for D-transposition of great arteries (D-TGA). However, the implications of ASO on pulmonaries, coronaries, and aorta have not been adequately investigated. The current study evaluates arterial morphologic changes post-ASO at intermediate-term surveillance.

METHODS

From May 2021 to May 2022, patients with D-TGA who underwent ASO for more than six months were recruited. Preoperative and operative data were collected. Patients were assessed using echocardiography (ECHO) and multislice CT angiography (MSCT) to evaluate pulmonary, coronary, and aortic arterial anatomy.

RESULTS

Twenty patients were included with median age of 11 (10-23.25) days at ASO and 14 (7.25-32.75) months on last follow-up. Neo-aortic regurgitation was detected in 12(60%) and neo-pulmonary regurgitation in 3 (15%). Using ECHO, complete evaluation of pulmonary arteries (PAs) was not achieved in 35% and incomplete coronaries assessment in 40% of cases. No stenosis was detected in coronaries using MSCT, although coronary anomalies were found in 9/20 (45%). Dilated Aortic annulus was detected in 16/20 (80%), dilated aortic root in 18/20 (90%), and dilated sinotubular junction in 70%. Right PA stenosis was diagnosed in 10/20 (50%) and left PA(LPA) stenosis in 7/20 (35%). Although Z-score of PAs did not correlate with aortic data, LPA bending angle was positively correlated to neo-aortic root diameter and Z-score (rho = 0.65,p = 0.016; rho = 0.69,p = 0.01), respectively.

CONCLUSION

Echocardiography alone is not a conclusive surveillance tool for detecting late post-ASO anatomic changes in D-TGA patients. Cardiac MSCT should be considered for comprehensive evaluation on the intermediate-term follow-up post-ASO to accurately track morphologic abnormalities in the aorta, pulmonary, and coronary arteries.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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).

Congenital Aortic Valve Repair When the Options aren't Good: Truncus Arteriosus and Transposition of the Great Arteries

Patients with truncus arteriosus and transposition of great arteries are prone to neo-aortic valve insufficiency. Although presenting at opposite ends of the age spectrum, both conditions tend to be commonly associated with neo aortic root dilatation. In patients with truncus arteriosus there is an additional complexity of quadricuspid valve morphology, which make up the majority of valves requiring repair. A unified approach to all these patients would include reduction and stabilization of the annulus and sinotubular junction, as well as achieving equal and symmetrical coaptation of the valve leaflets. By systematically employing these techniques, valve replacement should be avoidable in most children.

Comprehensive outcomes after primary arterial switch operation

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Is slim better than paunchy?

BACKGROUND

Aortopulmonary mismatch (APM) in transposition of the great arteries (TGA) may be accountable for dilatation of neoaortic root and regurgitation of neoaortic valve as late complications of arterial switch operation (ASO). The manuscript from Arcieri et al. highlights an important aspect of the ASO technique: should we approach APM during ASO and what would be the best strategy to do so?

DISCUSSION

Techniques to approach APM at the time of ASO have been published sporadically and are very rarely employed by surgeons. Reconstruction of the neoaorta is generally achieved by trimming the suture line between the pulmonary root (neoaortic root) and ascending aorta resulting in an abnormal dilated and bulky neoaortic root already at the time of ASO.

CONCLUSION

Reduction of the pulmonary root dimension by ressection of a fragment of the pulmonary artery wall possibly results in a more homogenous neoaorta with consequent better hemodynamics. We believe that approaching APM during ASO will have a compelling positive impact on the late survival of patients with complex TGA.

Modified Closed Coronary Transfer is a Good Alternative to the Trap-Door Method During Arterial Switch Operation: a Retrospective Propensity-Matched Comparison

Objective

To compare the early and long-term results of patients in whom was performed modified closed coronary transfer with the results of patients in whom was performed trap-door transfer techniques by utilizing propensity-matching analysis to provide optimal identical patient matching for the groups.

Methods

From August 2015 to December 2017, 127 consecutive patients underwent arterial switch operation due to simple and complex transposition of the great arteries, with or without additional arch and complex coronary pattern, by a single surgical team included into the study. Of these, in 70 patients it was performed modified closed coronary transfer technique and in 57 patients it was performed trap-door style coronary transfer technique. The patients were divided into two groups in terms of coronary transfer method. In the final model, after propensity matching, 47 patients from each group having similar propensity score were included into the study.

Results

There was no significant difference between the groups regarding patient characteristics. Cross-clamp time and operation time were significantly lower in the modified technique group compared with the other group (P=0.03 and P=0.05, respectively). When compared the early and late postoperative outcomes, there was no significant difference between the groups. Postoperative echocardiographic findings were mostly similar between the groups.

Conclusion

The patients in whom was performed our modified technique demonstrate overall good outcomes and the current technique ensures shorter arterial cross-clamp and operation times. It may be an alternative method to the trap-door technique for the coronary transfer during the arterial switch operation.

Neoaortic Regurgitation in Patients with Transposition Long Term After an Arterial Switch Operation and Its Relation to the Root Diameters and Surgical Technique Used

Neoaortic regurgitation and root dilatation are common findings in patients with transposition after an arterial switch operation. The aim of this study was to describe the relation between neoaortic regurgitation long term after an arterial switch procedure, aortic root diameters, and surgical technique used. We also assessed the agreement of the neoaortic regurgitation grade and root diameters in different imaging modalities. For this retrospective study, we qualified 56 consecutive patients who, according to our institutional protocol, had a routine postoperative evaluation of more than 16 years with multimodality imaging studies. Neoaortic regurgitation was assessed by both transthoracic echocardiography and magnetic resonance imaging, and the root diameters obtained by echocardiography and tomography were compared to the reference values and associated with the presence of neoaortic insufficiency. Neoaortic insufficiency was present in 75% of examined patients; the vast majority of them had trace or mild regurgitation, and its qualitative evaluation was significantly different between echocardiography and magnetic resonance imaging. In our study group, the neoaortic valve and aortic sinus were larger in relation to the normal values, and they were significantly correlated with the presence of neoaortic insufficiency, but not with the surgical technique used. Values obtained by echocardiography and tomography correlated well but were significantly different. Transthoracic echocardiography has a tendency to overestimate the severity of regurgitation compared to magnetic resonance imaging. Neoaortic valve and sinus dilatation are significantly correlated with valve insufficiency, but in most cases of root dilatation, the valve remains competent.

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.

Does Coronary Reimplantation After Neoaortic Reconstruction Increase Aortic Regurgitation?

Coronary reimplantation after neoaortic reconstruction (CRANR) in the arterial switch operation (ASO) allows easy selection of accurate coronary transfer sites in the distended neoaorta. However, neoaortic valve injury may occur during coronary reimplantation. We determined whether the CRANR procedure increased the incidence of aortic valve regurgitation (AR) after ASO. Between March 1994 and August 2017, 227 patients underwent ASO. Since September 2000 CRANR has been performed on 155 patients and open coronary reimplantation (OCR) on 72. Patients who had undergone aortocoronary flaps procedures (n = 13), had early or late mortality (n = 27), or lacked data (n = 11) were excluded. We enrolled and retrospectively reviewed the medical records of 176 patients who were followed up for postoperative AR: 38 underwent OCR and 138 underwent CRANR. We compared the incidences of early and late postoperative AR in both groups. We defined mild or greater AR as "significant AR." The groups did not differ in body weight at operation, great artery relationship, and coronary artery anatomy. The incidences of significant AR at discharge were 21.1% (8/38) in the OCR group and 16.6% (23/138) in the CRANR group (p = 0.53). The freedom from significant AR at 5 years was 59.9% in the OCR group and 62.4% in the CRANR group with no difference between the two groups (p = 0.73). Moderate AR occurred in one patient in the CRANR group. No surgical intervention was required for the aortic valve in either group. ASO using the CRANR technique did not increase the incidence of postoperative early and late AR.

Neo-aortic insufficiency late after staged reconstruction for hypoplastic left heart syndrome: impact of differences in initial palliative procedures

The neo-aortic insufficiency in patients with hypoplastic left heart syndrome is an important sequela. We assessed the risks of the neo-aortic valve deterioration by the difference of initial palliations: Group I underwent primary Norwood (Nw) with systemic-to-pulmonary artery shunt (SPS), Group II underwent bilateral pulmonary artery banding (bPAB) and subsequent Nw with SPS (bPAB-Nw/SPS), Group III underwent bPAB and subsequent Nw with bidirectional Glenn (BDG) procedure (bPAB-Nw/BDG). The neo-aortic valve z score changes over time did not reach statistical significance in all groups (p = 0.43 for Group I, 0.20 for Group II, and 0.30 for Group III). The degree of neo-aortic valve insufficiency did not change significantly over time during this period except for Group III (p = 0.34 for Group I, 0.20 for Group II, and 0.02 for Group III). On the other hand, dimensions of the neo-aortic annulus and degrees of neo-aortic insufficiency did not differ significantly among the 3 groups at any pre-determined time. The presence or absence of incision into the sino-tubular junction at Nw did not affect the late neo-aortic valve z score or insufficiency. These data indicate that the difference of initial palliative procedures does not affect late neo-aortic valve insufficiency in Nw survivors. Because valve failure may develop in longer follow-up, further observation should be conducted.

The great debate series: surgical treatment of aortic valve abnormalities in children

This article is the latest in an EJCTS series entitled 'The Great Debates'. We have chosen the topic of aortic valve (AoV) surgery in children, with a focus on infants and neonates. The topic was selected due to the significant challenges that AoV problems in the young may present to the surgical team. There are many areas of active controversy, despite the vast accumulated world experience. We have tried to incorporate many of these issues in the questions posed, not claiming to be all-inclusive. The individuals invited to this debate are experts in paediatric valve surgery, with broad and successful clinical experiences on multiple continents. We hope that the facts and opinions presented in this debate will generate interest and discussion and perhaps prove useful in decision-making for future complex valve cases.

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.

Echocardiographic assessment of the right ventricle in the current era: Application in clinical practice

The right ventricle has unique structural and functional characteristics. It is now well recognized that the so-called forgotten ventricle is a key player in cardiovascular physiology. Furthermore, there is accumulating evidence that demonstrates right ventricular dysfunction as an important marker of morbidity and mortality in several commonly encountered clinical situations such as heart failure, pulmonary hypertension, pulmonary embolism, right ventricular myocardial infarction, and adult congenital heart disease. In contrast to the left ventricle, echocardiographic assessment of right ventricular function is more challenging as volume estimations are not possible without the use of three-dimensional (3D) echocardiography. Guidelines on chamber quantification provide a standardized approach to assessment of the right ventricle. The technique and limitations of each of the parameters for RV size and function need to be fully understood. In this era of multimodality imaging, echocardiography continues to remain a useful tool for the initial assessment and follow-up of patients with right heart pathology. Several novel approaches such as 3D and strain imaging of the right ventricle have expanded the usefulness of this indispensable modality.

Outcomes after Arterial Switch Operation for Simple Transposition

Without intervention, babies born with transposed great arteries (TGA) are doomed to a rapid death. Jatene and coworkers deserve the credit for performing the first successful arterial switch operation (ASO) in a patient with TGA and ventricular septal defect (VSD) in 1975. Since then ASO has become the procedure of choice in most medical centers. This review article summarizes the historical aspects of arterial switch operation and assesses this procedure's outcomes.

Midterm outcome of primary arterial switch operation beyond six weeks of life in children with transposition of great arteries and intact ventricular septum

BACKGROUND

We have previously reported our experience in primary arterial switch operation (ASO) in children more than six weeks with transposition of great arteries and intact ventricular septum (TGA/IVS). The upper age limit for performing an ASO in these children is not yet settled and reports regarding outcome of ASO in these children are few. In this prospective observational study, we report the midterm results of children with TGA-IVS older than six weeks undergoing primary ASO.

METHODS

A total of 109 children aged more than 6 weeks with median age of 60 days (range 42-3,000 days), with regressed left ventricle underwent primary ASO. Extracorporeal membrane oxygenation was used in 20% (22 of 109) of them; 90.8% (99 of 109) of children who survived were prospectively followed, with a mean follow-up of 28 months (range 18-84 months).

RESULTS

Two late deaths occurred, and survival in the remainder was estimated to be 98% at seven years. The incidence of aortic regurgitation (AR) was found to have a decreasing trend with freedom from AR approaching 100% by 34 months. The left ventricular shape and function returned to normal within one to three months following surgery. None of these children had any rhythm disturbances or evidence of myocardial ischemia.

CONCLUSIONS

Primary ASO can be safely performed in children with regressed ventricle, irrespective of age with encouraging results. The midterm results of these children are comparable in terms of survival and freedom from complications associated with preserved ventricle.

The neoaortic root in children with transposition of the great arteries after an arterial switch operation

OBJECTIVES

Neoaortic root changes in children with transposition of the great arteries (TGA) are reportedly risk factors for the development of neoaortic regurgitation (NeoAR). The aims of this study were to assess the neoaortic root diameter and relative proportion in children with TGA after surgical correction and to identify possible correlations with the development of neoaortic insufficiency.

METHODS

Of the 611 children who had the arterial switch operation performed in the Cardiology Department of the Polish Mother's Memorial Hospital, 172 consecutive patients were qualified for this study. The inclusion criteria were: anatomical correction performed during the neonatal period, more than 10 years of postoperative observation and at least two full echocardiographic examinations.

RESULTS

NeoAR increased during postoperative follow-up and at the end of the observation period, 76% of the patients had NeoAR (27%-trace, 42%-mild, 7%-moderate and 0.6%-severe). Among the analysed risk factors for NeoAR development, the significant ones were arterial valve discrepancy (OR = 2.05; 95% CI: 1.04-4.02; P = 0.031) and the non-facing commissures (OR = 4.05; 95% CI: 1.34-11.9; P = 0.01). The neoaortic root diameter was not statistically significantly correlated with the presence of NeoAR or with the heart defects associated with transposition. The neoaortic root was initially, on average, 37% (z-score = 1.58) bigger than the aortic root in healthy children. This disproportion increased during the follow-up evaluations to 57% (z-score = 2.09).

CONCLUSIONS

The neoaortic root in children after the arterial switch procedure develops differently from that in healthy children, but this is not evidently related to NeoAR development or associated heart defects.

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

BACKGROUND

After the arterial switch operation (ASO) for transposition of the great arteries (TGA), the native pulmonary root and valve function in the systemic position, and the long-term risk for neoaortic root dilation and valve regurgitation is currently undefined. The aim of this study was to determine the prevalence and progression of neoaortic root dilation and neoaortic valve regurgitation in patients with TGA repaired with the ASO.

METHODS

Measurements of the neoaortic annulus, neoaortic root at the level of the sinuses of Valsalva, and the degree of neoaortic regurgitation were assessed by serial transthoracic echocardiograms on 124 patients with TGA at a median follow-up of 7.2 years (range, 1 to 23 years) after the ASO at our institution.

RESULTS

Neoaortic root dilation with z scores of 2.5 or greater was identified in 66%, and the root diameter z score increased at an average rate of 0.08 per year over time after ASO. Freedom from neoaortic root dilation at 1, 5, 10, and 15 years after ASO was 84%, 67%, 47%, and 32%, respectively. Risk factors for root dilation include history of double-outlet right ventricle (p = 0.003), previous pulmonary artery banding (p = 0.01), and length of follow-up (p = 0.04). Neoaortic valve regurgitation of at least moderate degree was present in 14%. Neoaortic root dilation was a significant risk factor for neoaortic valve regurgitation (p < 0.0001). No patient required reintervention on the neoaorta or neoaortic valve during follow-up.

CONCLUSIONS

Progressive neoaortic root dilation is common in patients with TGA after the ASO. Continued surveillance of this population is required.

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.

Twenty-eight years' experience of arterial switch operation for transposition of the great arteries in a single institution

OBJECTIVES

We reviewed our 28 years of experience of arterial switch operation (ASO) for transposition of the great arteries to investigate late sequelae of this procedure.

METHODS

387 patients who underwent ASO from 1984 to 2010 were included in this retrospective study. The longitudinal data were estimated by the Kaplan-Meier method and compared using a log-rank test. Risk factors for late sequelae were analysed by the multivariable Cox proportional hazards model.

RESULTS

The mean follow-up time was 10.0 years. There were 13 early deaths and 17 late deaths. All late deaths were within 1 year, except for three patients. Actuarial survival was 92.2 and 91.6% at 10 and 20 years, respectively. Sixty-six patients (17.1%) had developed pulmonary stenosis (PS) and 29 patients (7.5%) had developed moderate or more aortic insufficiency (AI) during follow-up. Selective coronary angiography was performed in 210 patients (54.3%) at 9.6 ± 5.1 years after ASO. Left main tract occlusion was found in 2 patients (2/210; 1.0%) and hypoplastic left coronary artery was found in 10 patients (10/210; 4.8%). Among these 12 patients, 8 patients were asymptomatic. Re-operation was performed in 76 patients (19.6%), pulmonary artery plasty for PS in 58 patients (15.0%), aortic valve replacement for AI including two Bentall operations in 9 patients (2.3%) and others. Freedom from re-operation was 78.2 and 62.8% at 10 and 20 years, respectively. The risk factor for PS was the use of equine pericardium for reconstruction (P < 0.0001). Factors associated with moderate or more AI was the presence of left ventricular outflow tract obstruction (P = 0.004). There were no risk factors for late coronary lesions. Three hundred and forty surviving patients (340/357; 95.2%) were in NYHA functional class I. Treadmill test, which was performed on 217 patients (56.1%) at 14.3 ± 5.4 years after ASO, revealed that the maximum heart rate was 97.5 ± 7.6% of normal and peak oxygen consumption was 105.2 ± 20.5% of normal.

CONCLUSIONS

ASO was performed with satisfactory results in the overall survival and functional status. PS was the main reason for re-operation. Coronary lesions can appear late without any symptoms. Benefits of ASO can be achieved by long-term follow-ups of PS, AI and coronary lesions.

The arterial switch operation: 25-year experience with 258 patients

BACKGROUND

At our institution, the arterial switch operation for transposition of the great arteries has transitioned from the Gore-Tex patch (W.L. Gore & Associates, Flagstaff, AZ) for pulmonary artery reconstruction to redundant pantaloon pericardial patch (RPPP). The (U-shaped) coronary artery button was used for coronary reimplantation. This study investigates overall mortality and factors for neopulmonary artery, neoaortic, and coronary artery surgical reintervention.

METHODS

We performed a retrospective chart review of all patients who underwent arterial switch between 1983 and 2007. Our surgical database, operative reports, and cardiology clinic charts were reviewed. Time to event was plotted as Kaplan-Meier curves. Predictors of time-to-event were examined using Cox proportional hazard modeling.

RESULTS

A total of 258 patients underwent arterial switch during the study. Mortality declined from 15% (era I: 1983 to 1990) to 11% (era II: 1991 to 1998) to 7% (era III: 1999 to 2007). Era III had a significantly later time to death compared with era I (hazard ratio [HR] 0.62, p = 0.04). The RPPP had a lower neopulmonary artery reintervention rate compared with Gore-Tex; 9 of 225 (4%) versus 3 of 21 (14%), p = 0.008. Complex anatomy increased risk for neopulmonary reintervention (HR 3.3, p = 0.03). Surgical reintervention rate for coronary arteries was 2%. Complex coronary anatomy (HR 17.9, p = 0.01) predicted coronary reintervention. Predictors of neoaortic reintervention were prior pulmonary artery band (HR 4.3, p = 0.03), complex anatomy (HR 3.5, p = 0.01), and coronary artery anatomy (HR 3.5, p = 0.04).

CONCLUSIONS

Arterial switch operation mortality has decreased. Conversion to RPPP reduced neopulmonary artery reintervention. The (U-shaped) coronary artery button technique is associated with low coronary reintervention rates. Complex coronary anatomy increases coronary and aortic reintervention. Prior pulmonary artery banding and complex anatomy increase aortic reintervention.

Is the function of all cardiac valves after the arterial switch operation influenced by an associated ventricular septal defect?

A ventricular septal defect in transposition of the great arteries is frequently closely related to the cardiac valves. The valvar function after arterial switch operation of patients with transposition of the great arteries and ventricular septal defect or intact ventricular septum was compared. We analysed the function of all cardiac valves in patients who underwent the arterial switch operations pre- and post-operatively, 1 year after the procedure and on follow-up. The study included 92 patients - 64 with transposition of the great arteries/intact ventricular septum and 28 with transposition of the great arteries/ventricular septal defect. The median age at surgery was 5.5 days in transposition of the great arteries/intact ventricular septum (0-73 days) and 7.0 days in transposition of the great arteries/ventricular septal defect (4-41 days). Follow-up was 51.7 months in transposition of the great arteries/intact ventricular septum (3.3-177.3 months) and 55 months in transposition of the great arteries/ventricular septal defect (14.6-164.7 months). Neo-aortic, neo-pulmonary, and mitral valvar function did not differ. Tricuspid regurgitation was more frequent 1 year post-operatively in transposition of the great arteries/ventricular septal defect (n = 4) than in transposition of the great arteries/intact ventricular septum. The prevalence of neo-aortic regurgitation and pulmonary stenosis increased over time, especially in patients with transposition of the great arteries/intact ventricular septum. The presence of a ventricular septal defect in patients undergoing arterial switch operation for transposition of the great arteries only has a minor bearing for the development of valvar dysfunction on the longer follow-up.

Neoaortic Valve Function 10 to 18 Years After Arterial Switch Operation

Anatomical correction is a procedure of choice for transposition of the great arteries (TGA) in neonates. During surgery, the aorta and pulmonary artery are switched—the native pulmonary valve becomes the neoaortic valve. The fate of this valve remains uncertain. Many reports suggest that its ability to function worsens with time after surgery. Of 519 patients with TGA operated on between 1991 and 2008, 161 met inclusion criteria for this retrospective study and were followed 10 years or more to assess neoaortic valve regurgitation (NeoAR) occurrence and development and to estimate potential risk factors. The subjects were divided into 2 groups: group 1 (simple TGA) and group 2 (TGA + ventricle septal defect). Within the analyzed group, the frequency of significant regurgitation increased from 9% 1 year after the operation to 47% at the most recent follow-up. No severe regurgitation necessitating reoperation was observed. Analysis of potential risk factors revealed that pulmonary/aortic valve diameter discrepancy and nonfacing commissures were associated with increased risk of development of neoaortic insufficiency. NeoAR arises and develops over time after correction of the defect. No hemodynamic repercussions necessitating cardiac surgical interventions were observed. The majority of insufficiencies are detected between 2 and 6 years after surgery. The degree of incompetence is usually mild and increases during follow-up by about 0.5 or 1 degree. The risk factors for NeoAR appearance are pulmonary artery/aortic annulus discrepancy and nonfacing commissures.

Correlations of phenotype and genotype in relation to morphologic remodelling of the aortic root in patients with Turner's syndrome

BACKGROUND

Patients with Turner's syndrome are at risk of aortic dilation and dissection. Currently, it is not known whether such dilation is related to associated cardiovascular abnormalities, or to the genetic anomaly itself.

METHODS

We studied echocardiographically 107 patients with genetically proven Turner's syndrome, with heterogeneous underlying karyotypes, and without associated cardiac lesions. Their average age was 19.6 plus or minus 8.4 years. We compared the finding with those from 71 age-matched healthy female volunteers. The diameter of the aorta was measured at the level of the basal attachments of the aortic valvar leaflets, the sinuses of Valsalva, the sinutubular junction, and its ascending component.

RESULTS

Compared to control subjects, the patients with Turner's syndrome had larger diameters of the aorta at the level of the sinuses of Valsalva, at 23.4+/-4.8 versus 25.5+/-4.1 millimetres (p = 0.0014), the sinutubular junction, at 19.9+/-3.8 versus 23.3+/-4.1 millimetres (p < 0.0001), and the ascending aorta, at 22.3+/-4.9 versus 24.6+/-4.4 millimetres (p = 0.0011). Dilation of the sinutubular junction, found in just over one-quarter of the patients, was more common than dilation of the ascending aorta, the latter found in less than one-tenth. The patients with Turner's syndrome, therefore, presented with remodelling of the aortic root, with relative dilation of the sinutubular junction. The underlying karyotype influenced both the dimensions of the sinutubular junction (p = 0.0054), and the ascending aorta (p = 0.0064), so that patients with the karyotype 45X had larger aortas. The karyotype was the strongest predictor by multivariate analysis for dilation at both these sites (p = 0.0138 and 0.0085, respectively).

CONCLUSIONS

Dilation at the sinutubular junction is frequent in patients with Turner's syndrome, and is more common than dilation of the ascending aorta. The syndrome is associated with a remodelling of the aortic root, with prominent dilation of the sinutubular junction. There seems to be a relation between aortic dilation and the underlying genotype.