Operation For Transposition Research Articles

Three-dimensional geometry of coronary arteries after arterial switch operation for transposition of the great arteries and late coronary events

ObjectiveUsing 3-dimensional (3D) modeling to predict late coronary events after the arterial switch operation (ASO) for transposition of the great arteries (TGA). MethodWe reviewed 100 coronary computed tomography scans performed after ASO randomly selected from free-from-coronary-event patients and 21 coronary computed tomography scans from patients who had a coronary event later than 3 years after ASO. Using 3D modeling software, we defined and measured 6 geometric criteria for each coronary artery: Clockwise position of coronary ostium, First centimeter angle defined as the angle between of the coronary artery ostium and the first centimeter of the vessel, Minimal 3D angle between the coronary first centimeter and the aortic wall, ostium height defined as the distance between the ostium and the aortic valve, distance between the coronary ostium and the pulmonary artery, and distance between the coronary first centimeter and the pulmonary artery. ResultsNone of the right ostium geometric parameters were associated with coronary events. Four out of 6 criteria of left coronary artery geometry were associated to coronary events: Clockwise position of the left ostium >67° (P < .001), First centimeter angle >62° (P < .01), minimal 3D angle <39° (P = .003), distance between the coronary ostium and the pulmonary artery <1 mm/mm (P = .03). The association of first centimeter angle >62° and minimal angle in 3D <39° had a 88% sensitivity and a 81% specificity to predict coronary events (receiver operator characteristics curve, 0.847; 95% confidence interval, 0.745-0.949; P < .001). ConclusionsThe acquired geometric characteristics of the transferred left coronary artery are associated with coronary events. Imaging coronary arteries after ASO might be useful to select patients at higher risk of coronary events and to tailor surveillance.

Comparative Outcomes of Primary Arterial Switch Operation for Transposition of Great Arteries within the First Month of Life

Background: The optimal surgical plan to correct the simple transposition of the great arteries (TGA) is the arterial switch operation (ASO). This study aimed to assess the outcomes of ASO in infants with simple TGA with a special focus on the time of surgery. Methods: This retrospective study enrolled 105 infants with simple TGA who underwent ASO and categorized them into 3 groups based on the time of repair: first week of life: Group A; second week of life: Group B; and third week of life: Group C. The endpoints, comprised of an assessment of pre- and postoperative outcomes, complications, and survival, were compared between the groups. Results: The mean age of the infants was 10.50±6.26 days, and 61 (58.1%) cases were male. The mean number of days on dopamine was 1.85±0.12 in Group A, 2.48±0.03 in Group B, and 2.67±0.08 in Group C (P<0.001). The mean number of days on epinephrine was 1.25±0.07 in Group B and 1.27±0.08 in Group C (P<0.001). The mean number of days on the ventilator was 3.52±0.20 in Group A, 4.56±0.24 in Group B, and 5.06±0.21 in Group C (P<0.001). The mean number of days of ICU stay was 6.69±0.21 in Group A, 8.46±0.57 in Group B, and 9.70±0.64 in Group C (P<0.001). The infants in Group A had a greater survival rate (97.0%) than those in Group B (94.1%) and Group C (78.4%) (P=0.042). Conclusion: ASO in infants with simple TGA can be done within the first week of life with satisfactory outcomes and survival.

Surgeries in Neonates and Small-Weight Babies With Congenital Heart Diseases: Challenges and Gratification

Background: Complex cardiac surgery in neonates and small-weight babies is a challenge. In addition to the surgical expertise and skill required, accurate diagnosis, management of anesthesia, perfusion, and postoperative critical care are equally challenging. Methods: We have analyzed the data of 4 different examples of complex cardiac surgery in neonates and small-weight babies from February 2012 to July 2019 in our unit. The first group included 118 cases of arterial switch operations for transposition of great arteries with and without ventricular septal defect (group 1). The second group included 52 patients of aortic arch repair from midline using selective cerebral perfusion avoiding total circulatory arrest (group 2). The third group included 75 patients of repair of coarctation of aorta from thoracotomy using the modified end-to-side technique (group 3). The fourth group included 40 neonates and small-weight babies who underwent repair of total anomalous pulmonary venous connection (group 4). Results: In group 1, there was hospital mortality in 6 babies. In group 2, there was no hospital mortality. In group 3, there was 1 hospital death; in group 4, there were 5 hospital deaths. The major contributing cause of death was respiratory or blood-borne infection causing respiratory issues leading to prolonged ventilation. Left diaphragm palsy contributed to morbidity and eventual death in 2 babies. Only 2 patients required tracheostomy to wean off the ventilator. Conclusions: In the present day, it is possible to achieve satisfactory results with acceptable mortality in neonatal cardiac surgery. Morbidity associated with very early repair in neonatal age, low weight, and infection-related issues is manageable with good outcomes.

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

Introduction and objectivesThere 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. MethodsWe 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. ResultsAt 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). ConclusionsIn adult life, NRD and AR progress over time after ASO. Predictors of progressive AR are bicuspid valve, AR at baseline, and increase in NRD.

Echocardiography and MRI parameters associated with exercise capacity in patients after the arterial switch operation

BackgroundThe arterial switch operation (ASO) for transposition of the great arteries has excellent survival, but a substantial number of patients suffer from a reduced exercise capacity. The goal of this study was to identify imaging parameters associated with a reduced exercise capacity in patients after ASO. MethodsA retrospective analysis was performed of ASO patients who underwent cardiopulmonary exercise testing (CPET) between 2007 and 2017. Reduced exercise performance was defined as a reduced workload peak (Wpeak) with Z-score <−2 or a peak oxygen uptake indexed for weight (VO2peak/kg) with Z-score <−2. Data on echocardiography and cardiac magnetic resonance performed within 1 year of the CPET were collected for comparison. ResultsA total of 81 ASO patients (age 17±7 years) were included. Reduced exercise performance was found in 22 patients (27%) as expressed by either a reduced Wpeak and/or a reduced VO2peak/kg. Main pulmonary artery gradient and tricuspid regurgitation gradient by echocardiography were found to be associated with reduced Wpeak (p=0.031; p=0.020, respectively). The main pulmonary artery gradient and tricuspid regurgitation gradient by echocardiography were found to be associated with reduced VO2peak/kg (p=0.009; p=0.019, respectively). No left ventricular parameters were found to be associated with abnormal exercise performance. ConclusionThis study demonstrates that ASO patients frequently experience reduced exercise capacity. Echocardiographic evidence of main pulmonary artery stenosis and increased right ventricular pressure were associated with reduced exercise capacity, and are therefore key to monitor during serial follow-up of ASO patients.

Outcome of arterial switch operation for transposition of the great arteries. A 35-year follow-up study

BackgroundArterial switch operation (ASO) is today the first-choice surgical treatment for patients with transposition of the great arteries. Long-term outcome data still remain scarce. Moreover, the course of these patients is not uneventful. Therefore, we wanted to evaluate long-term outcome and determine on which variables to focus during follow-up. MethodsClinical records of 318 patients who underwent ASO between October 1981 and July 2018 were reviewed. Perioperative, post-operative, and interventional data were collected to determine mortality and the need for re-intervention. Descriptive statistics and Kaplan-Meier survival analysis were performed. ResultsMean follow-up time was 11.1 SD 8.5 years (range 0–35) with a mean age of 12.5 SD 9.0 years (range 0–37) at latest follow-up. In-hospital mortality was 7.5% and overall survival 90.9% for a maximum follow-up time of 35 years. Causes of early mortality were cardiogenic shock, severe pulmonary hypertension, septic shock and multiple organ failure. Causes of late mortality were cardiogenic shock, severe pulmonary hypertension, pacemaker lead fracture and fire death. Re-intervention free survival at 5-year was 91.6%, at 10-year 90.7%, at 20-year 79.2%. For all survivors, the most frequent sequelae after ASO were pulmonary artery stenosis (80.9%), of which 13.5% needed an intervention. The threshold for intervening on lesions at the level of the pulmonary artery bifurcation was higher and the percutaneous re-intervention rate was higher for non-bifurcation lesions. ConclusionsDespite a relatively high peri-operative mortality, TGA patients have an excellent overall long-term survival. However, a large proportion of patients requires re-interventions, mainly for pulmonary artery stenosis.

Generic Sequences and the Generic Tonnetz

This article employs concepts from diatonic set theory, transformation theory, and neo-Riemannian theory in an investigation of sequences in generic (mod-7) pitch space. Sequences may be described using generic transposition operators, mod-7 analogs of the more familiar mod-12 chromatic transposition operators, and may be mapped in a generic Tonnetz analogous to the Tonnetz diagrams of neo-Riemannian theory. A complete classification of generic sequences with two-chord transposition blocks is derived from the paths described by the sequences in the Tonnetz. While it is tempting to regard generic space as “diatonic,” the examples demonstrate that generic structure governs many sequences that are not actually diatonic at all. The examples also show that the sequences found in the literature include many more types than are widely recognized and that generic sequence structure may apply in numerous other contexts besides patterns of chord roots.

Progresión y predictores de insuficiencia valvular neoaórtica y dilatación de la raíz neoaórtica en adultos jóvenes tras cirugía de switch arterial

Introduction and objectivesThere 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. MethodsWe 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. ResultsAt 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). ConclusionsIn 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.

Surgical treatment of vertical strabismus. Part 2. Indications, scheduling, methods

Treatment of vertical strabismus will almost inevitably involve surgery when it is associated with hyperfunction of the inferior oblique muscle due to the weakness of vertical fusion (3.0-4.0 ave dptr), the presence of cyclotropy and torsional diplopia. Many operations aimed at weakening the lower oblique muscle have been described. However, they have a number of negative aspects associated with high invasiveness, difficulty of technical implementation due to the need for manipulations in the inaccessible area of the eye in proximity to the optic nerve, macular area, large vessels, as well as long duration of the operation, inability to dosage the result of the operation, low functional results. They are, to a large extent, absent in the operation of anterior transposition in which the neurofibrovascular bundle serves as the axis of rotation of the lower oblique muscle changing the vector of its action and increasing the effectiveness of treatment. Despite all the advantages of that technique, its use is still limited due to the lack of methods for controlling the amount of anterior transposition for the treatment of hyperfunction of the inferior oblique muscle, especially of small degrees.

Altered Ascending Aorta Hemodynamics in Patients After Arterial Switch Operation for Transposition of the Great Arteries.

Patients with transposition of the great arteries (TGA) have an altered aortic geometry after an arterial switch operation (ASO), with neo-aortic root dilatation as an important complication. Geometry-related aortic hemodynamics have been assumed to contribute to pathology of the ascending aorta (AAo). To evaluate aortic flow displacement (FD) and regional wall shear stress (WSS) in relation to ascending neo-aortic geometry in children after ASO. Prospective. Twenty-eight TGA patients after ASO and 10 healthy volunteers. 3.0T/4D flow (segmented fast-spoiled echo pulse), noncontrast-enhanced MR angiography (Dixon), and anatomic images (SSFP). Aortic diameters and body surface area-indexed aortic dimensions (Z-scores), normalized FD and planar ascending aortic WSS. Mann-Whitney and chi-square tests for differences in FD magnitude, WSS, and FD directionality between groups, respectively. Spearman rank correlation to assess the degree of association between aortic geometry, FD and WSS parameters. Shapiro-Wilk test to evaluate distribution normality on the absolute differences in octant location between FD and WSS. TGA patients showed a significantly dilated proximal AAo and relatively small mid-AAo dimensions at the level of the pulmonary arteries (Z-scores neo-aortic root: 4.38 ± 1.96 vs. 1.52 ± 0.70, P < 0.001; sinotubular junction: 3.48 ± 2.67 vs. 1.38 ± 1.30, P = 0.010; mid-AAo: 0.32 ± 3.06 vs. 1.69 ± 1.24, P = 0.001). FD magnitude was higher in TGA patients (neo-aortic root: 0.048 ± 0.027 vs. 0.021 ± 0.006, P < 0.001; sinotubular junction: 0.054 ± 0.037 vs. 0.029 ± 0.013, P < 0.05) and was related to the neo-aortic Z-score. Clear areas of higher WSS at the right and anterior aortic wall regions along the distal AAo were detected in TGA patients, most pronounced in those with relatively smaller mid-AAo diameters. TGA-specific geometry related to the ASO, evidenced by neo-aortic root dilatation and a sudden change in vessel diameter at mid-AAo level, leads to more aortic flow asymmetry in the proximal AAo and WSS distribution with higher WSS at the right and anterior aortic wall regions along the distal AAo. 1 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2020;51:1105-1116.

P2742Right ventricular stroke volume during dobutamine stress magnetic resonance compared to lung perfusion and peak oxygen uptake after arterial switch operation for transposition of the great arteries

Abstract Objectives Abnormal pulmonary perfusion due to stenosis of the central pulmonary arteries is common after neonatal arterial switch operation (ASO) for transposition of the great arteries (TGA). We conducted a monocentric prospective study in young adults after neonatal ASO for TGA to evaluate the effects of abnormal pulmonary perfusion on the increase of the right ventricular stroke volume (RVSV) during dobutamine stress magnetic resonance (DSMR) and on cardiopulmonary exercise capacity. Methods 68 unselected patients (age 18–29 years) underwent CMR at rest and under dobutamine stress (10 to 40 μg/kg/min). RVSV, pulmonary blood flow distribution (PBFD) and peak flow velocity were derived from phase contrast mapping in the main, right and left pulmonary artery (PA) at rest and each stress level. A cardiopulmonary exercise test (CPET) was performed at the same day. All patients reached maximal exercise effort according to heart rate and respiratory exchange rate. Results PBFD at rest: 9/68 patients (13%, ASO-S) had abnormal pulmonary perfusion at rest, defined as PBFD &gt;2:1 (right/left or left/right) and/or relevant stenosis of the main PA (Vmax &gt;2.5 m/s). 59/68 patients (87%, ASO-N) had normal pulmonary perfusion. PBFD under DSMR: (1) In the whole patient group, there was no increase of PBFD under stress compared to PBFD at rest. On an individual patient level, no relevant worsening of abnormal PBFD was found. (2) Under low dose dobutamine, ASO-S had a significantly lower RVSV-increase (RVSVstress/RVSVrest) compared to ASO-N (see figure). However, under high dose dobutamine, this effect was no longer significant (see figure). (3) The RVSV-increase under low and high dose dobutamine did not correlate with peak oxygen uptake during CPET, neither in the total group nor in the subgroups (see table). Peak oxygen uptake was not significantly different between ASO-N and ASO-S (p=0,72). RVSV-increase compared to CPET peak VO2% ASO-total ASO-S ASO-N RVSV-increase/peak VO2% RVSV-increase/peak VO2% RVSV-increase/peak VO2% low dose dobu high dose dobu low dose dobu high dose dobu low dose dobu high dose dobu Pearson correlation coefficient −0.02 −0.05 0.01 −0.22 −0.05 −0.04 p-value 0.90 0.71 0.98 0.56 0.71 0.78 Figure 1 Conclusion (1) Patients with relevant stenosis of main PA and/or abnormal peripheral blood flow distribution (ASO-S) exhibit a reduced RVSV-increase under low dose dobutamine compared to patients without stenosis (ASO-N). This effect was not present under high dose dobutamine stress. (2) These findings did not correlate with peak oxygen uptake during CPET, an objective parameter of cardiopulmonary exercise capacity. (3) Therefore, a conservative proceeding rather than surgery or catheter intervention should be considered, especially in asymptomatic adult patients. Acknowledgement/Funding Supported by Kinderherzen, Fördergemeinschaft Deutsche Kinderherzzentren e.V.

P4692Pronostic factors after arterial switch operation for transposition of the great arteries in children

Abstract The objective of this study was to assess long-term outcome and factors associated wih mortality in children after arterial switch operation (ASO) for transposition of the great arteries (TGA). Material and methods Retrospective analysis of all ASO performed from 2000 to 2016 in patients with TGA. Demographics, clinical and biological data, surgical techniques, echocardiographic measurements, and outcomes were collected. Pronostic factors for mortality were assessed. Results 364 patients were included (263 males). Antenatal diagnosis was made in 60,4%. Birth weight was 3207,5±511.2g, gestational age was 39.1±1.6weeks. Intramural coronary artery was present in 24 cases (6.6%). Long term follow-up was 9.2±4.8 years. Rashkind procedure was performed in 88.7% of the cases. Ventilatory support was needed in 56% and prostaglandins in 85% preoperatively. ASO occurred at the age of 7.44±6.26 days (1 to 56) and 5.6±4.6 days after admission. Bypass duration was 123.1±33.3mn. Overall and postoperative hospital stay were respectively 19.9±8.6 and 14.4±7.3 days. Survival rates were 95.3% at 1 month, 94.8% at 3, 6 and 12 months and 94.5% at 2.5 years and up to 18 years after surgery. Twenty patients died (5.5%): 17 early postoperatively (4.7%). Time from surgery to death was 64.2±207.9 days (0 to 919). Long-term events occurred in 49.6% of the patients: pulmonary stenosis, aortic or mitral regurgitation, residual shunt, coronary lesions (1.7%), arrhythmias (5.5%), cardiac failure. Freedom from late reintervention was 99.7%, 97.4%, 96.2% at 1, 3 and 6 months, 95.9%, 95%, 92.3% and 90.3% at respectively 1, 2, 5 and beyond 8 years after ASO. No Rashkind, postoperative ECMO support, delayed chest closure, bypass duration, troponine level and small birth weight were significant predictive factors of mortality (respectively p=0.006, p&lt;0.0001, p=0.0007, p&lt;0.0001, p=0.001 and p=0.044). Antenatal diagnosis, gender, gestational age, preoperative ventilatory support, prostaglandin infusion, and SpO2, coronary arteries anatomy or age at surgery were not associated with death. Conclusion This study showed that Rashkind procedure may have a favourable impact on prognosis of neonates with TGA. Postoperative ECMO support and troponine level, and small birth weight were associated with worse outcome.

Arterial switch operation for transposition of the great arteries: A single-centre 32-year experience.

Arterial switch operation (ASO) is nowadays the standard of care for neonates with D-transposition of the great arteries (D-TGA). We evaluated our early and late results with ASO for D-TGA. We collected data on 267 patients with D-TGA, either with intact ventricular septum (D-TGA/IVS; n = 182, 68%) and with other associated congenital heart malformations (complex D-TGA; n = 85, 32%) that underwent ASO between January 1987 and July 2018. Median age at ASO was 8 days (interquartile range [IQR], 6-12 days). Fifteen patients (5.6%) died in hospital (6/182 with D-TGA/IVS, 3.3% and 9/85 with complex D-TGA, 11%; P = 0.02). Median follow-up time was 10.2 years (IQR, 3.7-18 years). There were 2 (0.8%) late sudden deaths. Overall survival at 10 and 20 years was 94% and 93%, respectively. Thirty-five patients (14%) required either reoperations or reinterventions, mainly for right ventricular outflow tract obstruction (n = 28, 11%). Freedom from reoperation/reintervention at 10 and 20 years was 87% and 78%, respectively. All patients were in NYHA I at latest clinical examination. Six over 173 patients (3.4%) who underwent a postoperative evaluation of their coronaries presented acquired anomalies. Forty-four patients (17%) who performed a cardiopulmonary exercise testing (CPET) have a predicted VO 2 comparable to normal peers. The results of ASO for D-TGA are excellent, with a fairly low mortality and reoperation/reintervention rate. Functional capacity evaluated with CPET is comparable to normal peers. Continuous follow-up for detecting asymptomatic acquired coronary artery disease is mandatory. A reassessment of competitive sport eligibility criteria for specific D-TGA patients should be considered.

32 year follow up of patients following atrial redirection surgery for transposition of the great arteries.

A significant body of patients who have undergone Mustard or Senning procedure require lifelong follow up. In this retrospective review, we examined the cohort of such patients currently attending our center. Patients who had undergone either Mustard or Senning procedure were identified. We retrospectively reviewed medical records, recorded demographic information and data regarding the clinical state, NHYA class, cardiopulmonary exercise testing, NT-proBNP measurement, and recent cardiac MRI findings. Forty-six patients were identified, the mean age was 32.2years (± 6.1years), 67.4% were male. Thirty-two patients (69.6%) had undergone a Senning procedure. The median length of the follow-up was 32years. Thirty-two patients (69.6%) were NHYA class 1. The mean VO2max achieved was 24.2±5.8mL/min/kg. The mean NT-proBNP was 266.4pg/mL (± 259.9pg/mL). The mean right ventricular end-diastolic volume (RVEDV) was 212.4mL±73.1mL (indexed 114.2mL/m2 ±34.4mL/m2 ). The mean right ventricular ejection fraction (RVEF) was 53.7% ± 7.9%. The mean left ventricular end-diastolic volume (LVEDV) was 161.5mL±73.7mL (indexed 87.8mL/m2 ±41.1mL/m2 ). The mean left ventricular ejection fraction (LVEF) was 59.8% ± 5.7%. There was a significant correlation between right ventricular (RV) size on MRI and NT-proBNP level. We present a relatively well cohort of patients with overall favorable long-term outcome. The majority of patients are NHYA class 1 and the systemic right ventricular function appears to be well preserved as assessed by MRI. The exercise tolerance is reduced, with the majority of patients achieving around 60% of the estimated VO2max . Regular specialist follow-up and assessment with advanced imaging at regular intervals remain important for this group.

Myocardial blood flow and cardiac sympathetic innervation in young adults late after arterial switch operation for transposition of the great arteries

BackgroundThe arterial switch operation (ASO) for repair of transposition of the great arteries (TGA) requires transection of the great arterial trunks and re-implantation of the coronary arteries into the neoaortic root resulting in cardiac sympathetic denervation which may affect myocardial blood flow (MBF) regulation. The aims of the present study were to evaluate sympathetic (re-)innervation in young adults after ASO and its impact on MBF. MethodsTwelve patients (age 22.5 ± 2.6 years) after ASO for TGA in the neonatal period and ten healthy controls (age 22.0 ± 1.7 years) were included. Positron emission tomography (PET) was used for measuring cardiac sympathetic innervation with [11C]meta-hydroxyephedrine (mHED) and MBF with [15O]H2O PET at rest, during adenosine stimulation, and during sympathetic stimulation with cold pressor test. Cold pressor-induced MBF response capacity was calculated as maximal global MBF over peak rate-pressure product multiplied by 10′000. ResultsGlobal [11C]mHED uptake was significantly lower in patients compared to controls (7.0 ± 2.3 versus 11.8 ± 2.1%/min, p < 0.001). Global MBF was lower in patients compared to controls at rest and during adenosine-induced hyperemia (0.66 ± 0.08 versus 0.82 ± 0.15 ml/min/g, p = 0.005; 2.23 ± 1.19 versus 3.36 ± 1.04 ml/min/g, p = 0.030, respectively). Interestingly, MBF during cold pressor test did not differ between patients and controls (0.99 ± 0.20 versus 1.07 ± 0.16 ml/min/g, p = 0.330). However, cold pressor-induced MBF response capacity was significantly lower for patients as compared to controls (1.09 ± 0.35 versus 1.44 ± 0.39 ml/g/10,000 mmHg, p = 0.040). ConclusionsWith only partial sympathetic re-innervation of the coronary arteries, maximal dilator capacity of the coronary microvasculature and cold pressor-induced MBF response capacity remain substantially impaired in young adults after ASO compared to healthy controls.

Right and Left Ventricular Strain Patterns After the Atrial Switch Operation for D-Transposition of the Great Arteries-A Magnetic Resonance Feature Tracking Study.

Introduction: Adult survivors of the atrial switch operation for transposition of the great arteries present with a systemic morphologic right ventricle and a subpulmonary morphologic left ventricle. This physiology can be considered a model for the effects of long-term right ventricular pressure overload and of decreased left ventricular afterload. We aimed to determine the impact of these chronically altered loading conditions on myocardial deformation of the ventricles.Materials and methods: Two-dimensional steady state free precession cine images of 29 patients after atrial repair (age 29 ± 7 years) and 19 controls (24 ± 10 years; n.s.) were post-processed with feature tracking software (TomTec 2D CPA). Volumes, ejection fractions, global and free wall longitudinal and circumferential strains of both ventricles were compared between both groups.Results: Systemic right ventricular global longitudinal strain was decreased in patients compared to controls (−12.9 ± 3.3% vs. −18.9 ± 4.6%, p < 0.001), while right ventricular circumferential strain was unchanged (−15.8 ± 3.4% vs. −15.1 ± 5%; n.s.). Left ventricular longitudinal strain was similar in both groups (−17 ± 5.6% vs. −17.5 ± 4.6%; n.s.), but global left ventricular circumferential strain was lower in patients (−20.7 ± 4.1% vs. −27.3 ± 4.5%, p < 0.001). The systemic right ventricle, compared to the systemic left ventricle, showed decreased global longitudinal (p < 0.001) and circumferential strain (p < 0.001). The subpulmonary left ventricle, compared to the subpulmonary right ventricle, demonstrated similar longitudinal (p = 0.223) but higher circumferential strain (p < 0.001).Conclusions: In patients after atrial switch repair for transposition of the great arteries, the systemic right ventricle shows poor longitudinal strain, but maintains normal right ventricular circumferential strain. The left ventricle shows higher circumferential strain than the right ventricle, in both systemic and subpulmonary positions.

Long-Term Results of Bay Window Technique for Coronary Translocation in the Arterial Switch Operation.

Accurate coronary translocation is very important for a successful arterial switch operation (ASO) for transposition of the great arteries (TGA) and to provide good long-term outcomes. We have previously reported the "bay window" technique as a useful option for coronary translocation with excellent midterm results. However, the long-term results of this technique and the morphological changes in the coronary channel have not yet been reported. Between September 2001 and December 2012, 33 patients with TGA underwent coronary translocation using the bay window technique concomitantly with ASO. The diagnoses were TGA with intact ventricular septum in 21, TGA with ventricular septal defect in 7, and Taussig-Bing anomaly in 5. The median age of the patients at operation was 12 days, and their median body weight was 2.93 kg. Coronary artery patterns were as follows: Shaher and Puddu's type 1 in 23, single coronary artery in 4, intramural type in 1, and others in 5. The median follow-up period was 4.5 years. There were no operative deaths, but there was one late death because of sepsis 13 months after ASO. Coronary artery evaluation with angiography, computed tomography, or myocardial scintigraphy was performed in 22 patients. There was no abnormal coronary morphology or perfusion. Coronary channel dilatation was not observed. Three patients underwent reoperation for pulmonary stenosis. The bay window technique provides excellent long-term results in ASO for TGA. Three-dimensional computed tomography revealed no aneurysmal changes in the bay window channel at nine-year follow-up examination.

Aortic angle is associated with neo-aortic root dilatation and regurgitation following arterial switch operation

IntroductionNeo-aortic root dilatation and regurgitation are common progressive long-term complications of the arterial switch operation (ASO) for transposition of the great arteries (TGA) with increasing clinical burden. While several risk factors have been identified, most are constitutional. The acute aortic angle commonly seen after ASO might alter aortic dynamics and facilitate progression of the neo-aortic root dilatation and aortic regurgitation, but insufficient data is available. We intend to assess the effect of the aortic angle in the extent of neo-aortic root dilatation and presence of regurgitation. MethodsRetrospective analysis of TGA patients undergoing CMR after ASO at a single tertiary centre from November 2010 to July 2017. Results180 patients were analysed, 157 of which having adequate imaging of the aortic arch and root. Neo-aortic root Z score was normally distributed with 73% of patients having a Z score > 2. The aortic angle had a significant (p < 0,001) inverse relationship with the neo-aortic root Z score both in univariate and multivariate linear regression. Other significant associations were male gender and the concomitant presence of a VSD or a dysplastic neo-aortic valve. The presence of neo-aortic regurgitation was also inversely correlated with the aortic angle. The presence of a bicuspid neo-aortic valve was another significant association, further correlating with the more severe forms. ConclusionsAcute aortic angles associate more extensive neo-aortic root dilatation and higher incidence of regurgitation. We believe a surgical technique promoting less acute aortic angles has potential for ameliorating the long-term outcomes of TGA.

Pulmonary artery interventions after the arterial switch operation: Unique and significant risks.

In the modern era, results of the arterial switch operation (ASO) for transposition of the great arteries are excellent. However, because of the LeCompte maneuver, there may be a propensity for development of pulmonary artery stenosis. We encountered atypical complications of pulmonary artery stenting in patients after the ASO, including aorto-pulmonary fistula and coronary compression. We performed a 10-year retrospective review of catheterizations performed in patients after ASO in our institution with a focus on adverse events. Diagnostic and interventional catheterizations were performed in 47 patients. In 29 patients, 37 interventional procedures performed, which included pulmonary artery angioplasty and/or stenting. In this group, there were five major adverse events (14%), including three aorto-pulmonary fistulae and one coronary artery compression among patients having stent implantation or stent redilation. In addition, there were 6/37 (16%) intended stent procedures, which were aborted because there appeared to be high-risk of significant adverse events. This review suggests that percutaneous intervention on pulmonary artery stenosis after ASO has high-risk and should be undertaken advisedly. Prior thorough evaluation of coronary arteries is mandatory as coronary reimplantation sites may be adjacent to sites of pulmonary artery stenosis. Furthermore, if pulmonary artery stent implantation or stent redilation is contemplated, the risk of stent fracture and possible AP fistula should be recognized. Primary use of reinforced covered stents should be considered.