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

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

Perfusion techniques for an 800 g premature neonate undergoing Arterial Switch Procedure for Transposition of the Great Arteries☠.

Early cardiac surgery in neonates and infants with congenital heart disease has been performed since the middle to late years of the twentieth century. To date, there are very few reports of successful congenital heart surgery using cardiopulmonary bypass (CPB) in premature babies less than 1000 g with serious congenital heart disease. Limited information is available in the literature describing perfusion techniques for this extremely fragile patient population. Miniaturization of the CPB circuit contributes to multiple factors that affect this population significantly. These factors include the reduction of patient-to-circuit ratios, volume of distribution of pharmacological agents, management of pressure gradients within the CPB system, and increased tactile control by the attending perfusionist. Careful management of the physiological environment of the patient is of utmost importance and can mitigate risks during CPB, including volume shifts into the interstitial space, electrolyte, and acid-base imbalance, and intracranial hemorrhage. We report perfusion techniques successfully utilized during the surgical repair of transposition of the great arteries for an 800 g, 28-week-old neonate. CPB techniques for the smallest and youngest patients may be executed safely when proper physical, chemical, and perfusion process adjustments are made and managed meticulously.

En Bloc Rotation of the Outflow Tracts - Double Root Translocation.

En bloc rotation of the outflow tracts or double root translocation offers an anatomic repair of transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction and closely related forms of double outlet right ventricle. The technical principle is to excise aortic and pulmonary root en bloc, rotate them as a whole by 180°, and reimplant them. The left ventricular outflow tract is enlarged with the patch closing the ventricular septal defect. In our experience, two thirds of the pulmonary valves could be preserved. Growth of the aortic and pulmonary root could be demonstrated in several studies performed by our group. It is still a complex and technically demanding procedure with long cardiopulmonary bypass periods and cross-clamp times. However, perioperative mortality and complications do not differ significantly from other forms of reconstruction. The reoperation rate is significantly lower. Presently, the best time to perform this operation seems to be after the newborn period within the first year of life.

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

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

Percutaneous pulmonary valve implantation in a patient with congenitally corrected transposition of the great arteries: a case report.

BACKGROUND: Percutaneous pulmonary valve implantation has become an attractive method of dysfunctional right ventricle outflow tract treatment. CASE PRESENTATION: We describe a unique case of a 20-year-old Caucasian male patient with a complex cyanotic heart defect, namely pulmonary atresia, with congenitally corrected transposition of the great arteries and ventricular septal defect after Rastelli-like surgery at the age of 5 years with homograft use. At the age of 20 years, the patient needed percutaneous pulmonary valve implantation owing to homograft dysfunction. Despite unusual course of the coronary arteries, balloon testing in the landing zone of the right ventricle outflow tract excluded potential coronary artery compression. Then, after presentation, a Melody valve was implanted successfully in the pulmonary valve position. The 8-year follow-up was uneventful. CONCLUSION: This is likely the first description of a percutaneous pulmonary valve implantation in such anatomy. Such a procedure is feasible; however, it requires exceptional caution owing to the anomalous coronary arteries course, which can be the reason for their compression.

Use of Interactive Visualization and 3D Printing in the Repair of Complex Congenital Heart Disease Presenting in Adult Life.

We report a case of a 25-year-old male with a heterotaxy-like constellation of congenital heart defects consisting of complete atrioventricular septal defect, transposition of the great arteries, subpulmonary stenosis, L-looped ventricles, hypoplastic right ventricle, and a distant aorta arising from the right ventricle. This case demonstrates how 3D printing and interactive 3D visualization may facilitate a unique surgical repair.

Bioptome-assisted blunt dissection facilitates endovascular retrieval of a chronically embolized stent.

We present a 19-year-old female with history of d-transposition of the great arteries status post-arterial switch operation.

Hemodynamic simulation of complete transposition of the great arteries for optimal treatment strategies based on its circulatory physiology.

Our study aimed to elucidate the role of different shunts and provide novel insights into optimal treatment approaches for complete transposition of the great arteries (TGA), which is characterized by unique and complicated circulatory dynamics. We constructed a computational cardiovascular TGA model and manipulated cardiovascular parameters, such as atrial septal defect (ASD) and patent ductus arteriosus (PDA) sizes, to quantify their effects on oxygenation and hemodynamics. In addition, ASD flow patterns were investigated as innovative indications for balloon atrial septostomy (BAS). Our model of TGA with an intact ventricular septum (TGA-IVS) showed that a large ASD can achieve sufficient mixing for survival without PDA, and the presence of PDA is detrimental to oxygen delivery. A treatment strategy for TGA-IVS that enlarges the ASD as much as possible by BAS and PDA closure would be desirable. In TGA with a ventricular septal defect (TGA-VSD), the VSD allows for higher oxygenation and reduces the detrimental effects of PDA on systemic circulation. In TGA-VSD, both strategies of enlarging the ASD by BAS with a closed PDA and adjusting the PDA in response to pulmonary vascular resistance (PVR) reduction without BAS may be effective. The simulated ASD flow patterns showed that the sharp peak left-to-right flow pattern in systole (σ-wave) reflected the hemodynamically significant ASD size, independent of PDA, VSD, and PVR. The ASD flow pattern visualized by Doppler echocardiography provides clinical insights into the significance of an ASD and indications for BAS, which are not readily apparent through morphological assessment.NEW & NOTEWORTHY Complete transposition of the great arteries (TGA) represents complex and unique circulation that is dependent on blood mixing through multiple interacting shunts. Consequently, the role of each shunt and the treatment strategy remain unclear. We developed a mathematical model of TGA circulation, revealing the significant influence of atrial septal defect (ASD) on oxygenation and hemodynamics. The blood flow pattern through the ASD reflects its hemodynamic impact and helps determine treatment strategies.

A short RP tachycardia in congenitally corrected transposition. What is the mechanism?

A 51-year-old female with congenitally corrected transposition of great arteries (CCTGA), situs solitus, dextrocardia, atrial septal defect and persistent left superior vena cava underwent electrophysiology study for recurrent palpitations with documented narrow complex, short RP tachycardia. With a catheter in the region of the anterior mitral annulus, a His signal was recorded and HV interval was 35 msec. Tachycardia was induced with a ventricular extrastimulus. During the tachycardia there was 1:1 ventriculo-atrial conduction and central atrial activation with a VA interval of 20 msec. The recorded His signal could be seen after the QRS. What is the mechanism of the tachycardia?

Left atrial strain in adults after the arterial switch operation for transposition of the great arteries.

BACKGROUND: No study has focused on left atrial (LA) function assessed by echocardiography in adult patients with simple D-TGA after arterial switch operation (ASO). We aimed to describe LA strain parameters in these patients. METHODS: A prospective cohort study including 42 adult patients with simple D-TGA after ASO and 33 aged-matched controls. Phasic LA and LV global longitudinal strain (GLS) were obtained by transthoracic 2D-speckle tracking echocardiography (STE). Volumetric and functional analysis of LA and LV were also evaluated by 2D and 3D analysis. A multivariable model was performed to investigate the variables that best differentiate patients with D-TGA from healthy controls. RESULTS: LA strain parameters in D-TGA patients were within the normal range described for healthy subjects. However, the three LA strain parameters (Reservoir, Conduit, and Contraction) were lower in patients (LASr: 31.13 ± 7.67 vs. 49.71 ± 8.38; LAS cd: -22.91 ± 5.69 vs. -34.55 ± 6.54; LASct: -8.14 ± 4.93 vs. -15.15 ± 6.07, p < .001 for all three comparisons). LA volumes were similar between patients and controls. LV-GLS remained significantly lower in the D-TGA group than in controls (-17.29 ± 2.68 vs. -21.98 ± 1.84, p < .001). D-TGA patients had evidence of worse LV ejection fraction measured by the Teichholz method (63.38 ± 8.23 vs. 69.28 ± 5.92, p = .001) and 3D analysis (57.97% ± 4.16 vs. 60.67 ± 3.39, p = .011) and diastolic dysfunction as compared to healthy controls. LV-GLS and conduit LAS were the variables best differentiating patients with D-TGA from healthy controls. CONCLUSIONS: LA strain is impaired in young adults with simple D-TGA late after the ASO, probably in agreement with some degree of LV dysfunction previously described.

A successful cardiac transplant in a patient with situs inversus totalis and congenitally corrected transposition of the great arteries.

A heart transplant is the gold standard therapy for patients with end-stage heart failure. In this case report, situs inversus totalis and congenitally corrected transposition of the great arteries led to a unique and complex preoperative setting. Extended donor organ harvesting, donor graft rotation of 45° to the right and post-operative stenting of the superior vena cava were essential steps in the interdisciplinary management of this case. The patient was transferred to the intensive care unit with moderate inotropic support. He was discharged to rehabilitation on postoperative day 89 and eventually underwent an additional renal transplant 14 months after the cardiac transplant.

Multi-modality imaging of the systemic right ventricle in congenital heart disease.

A comprehensive and structured imaging approach in the evaluation of the systemic right ventricle (sRV) in patients with complete transposition of the great arteries (TGA) after atrial switch procedure and congenitally corrected transposition of the great arteries (ccTGA) is a key for their optimal lifelong surveillance. Despite the improvements in cardiovascular imaging of adults with congenital heart disease (ACHD), the imaging of sRV remains an ongoing challenge due to its complex morphology and the difficulty in applying the existing knowledge for the systemic left ventricle. While cardiac magnetic resonance (CMR) is considered the gold standard imaging method, echocardiographic evaluation is primarily preferred in everyday clinical setting. Although qualitative assessment of its systolic function is primarily used, the introduction of advanced echocardiographic techniques, such as speckle tracking echocardiography (STE) and three-dimensional echocardiography (3DE), has provided new insights into the optimal assessment of the sRV. Standardized quantitative parameters remain to be elucidated, and morphometric and mechanistic studies are warranted to validate reference ranges for the sRV. This review highlights the challenges in the optimal evaluation of sRV and summarizes the available imaging tools. HIGHLIGHTS: CMR is the gold standard imaging method of sRV. Qualitative assessment of the systolic function of sRV is primarily used. Advanced echocardiographic techniques (STE and 3DE) provide optimal sRV assessment. Reference ranges for the sRV indices are warranted to be validated.

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.

The Arterial Switch Operation in the Developing World: Risk Factors and Current Outcomes.

BACKGROUND: Published data on the outcomes of the arterial switch operation in the developing world are limited. We sought to identify the midterm outcomes of and risk factors for mortality and morbidity in patients undergoing the arterial switch operation at a high-volume center in Vietnam. METHODS: A retrospective review was conducted of 608 patients who underwent an arterial switch operation for the treatment of transposition of the great arteries (TGA; n = 509) or double-outlet right ventricle TGA (DORV-TGA; n = 99) at a single center from 2010 to 2021. RESULTS: Overall early mortality was 5.9%, and late mortality was 1%. Multivariate Cox regression showed weight at operation of <3 kg (P < .001), prolonged aortic cross-clamp time (P < .001), and need for secondary aortic cross-clamp (P = .011) as risk factors for overall mortality. The actuarial 10-year survival rate was 93%. The overall cardiac reoperation rate was significantly higher in patients with DORV-TGA (hazard ratio [HR], 16.43; 95% CI, 4.70-57.43; P < .001). The rate of freedom from cardiac reoperation at 10 years was 94%. Risk factors for outflow tract reoperation were patients with DORV-TGA (HR, 23.28; 95% CI, 2.86-189.66; P = .003), single coronary artery (HR, 4.1; 95% CI, 1.16-14.46; P = .028), and mild aortic valve regurgitation observed in 3.7% of patients. CONCLUSIONS: The outcomes of the arterial switch operation in a low- and middle-income country were satisfactory. Nevertheless, the complexity of the procedure and lower weight of patients are still challenges. Patients with DORV-TGA and single coronary artery need to be closely followed up.