Clinical Presentation and Therapy of Truncus Arteriosus.

Truncus arteriosus (TA, also known as common arterial trunk) consists of only one great artery ("the truncus") with a semilunar valve (truncus valve) arising from the heart and an additional ventricular septal defect and (Fig. 50.1). This great artery is positioned above the ventricular septal defect and gives rise to the coronary arteries, the pulmonary arteries, and the aortic arch. Historically, TA has been classified by Collet and Edwards in three types, where in type I there was a common pulmonary artery truncus, in type II the left and right PA arise separately but close to each other, in type III both PA arise independently; in addition, there was a type IV that was later characterized as pulmonary atresia with VSD and major aortopulmonary collateral arteries arising from the descending aorta.

Aortopulmonary Collateral Arteries in Noncyanotic Congenital Heart Disease.

Development of major aortopulmonary collateral arteries are strongly associated with cyanotic congenital heart disease. However, they have rarely been reported in noncyanotic congenital heart disease. We report a rare case of a newborn originally diagnosed with an atrial septal defect, a ventricular septal defect, and pulmonary arterial hypertension who underwent complete repair. Failure to progress postoperatively lead to the delayed diagnosis of aortopulmonary collateral arteries. Percutaneous embolization and surgical ligation of aortopulmonary collateral arteries resulted in rapid recovery.

The Hemodynamics of Patent Ductus Arteriosus in Patients after Central Shunt Operation.

A central shunt (CS) was an important surgery of systemic-to-pulmonary shunt (SPS) for the treatment of complex congenital heart diseases with decreased pulmonary blood flow (CCHDs-DPBF). There was no clear conclusion on how to deal with unclosed patent ductus arteriosus (PDA) during CS surgery. This study expanded the knowledge base on PDA by exploring the influence of the closing process of the PDA on the hemodynamic parameters for the CS model. The initial three-dimensional (3D) geometry was reconstructed based on the patient's computed tomography (CT) data. Then, a CS configuration with three typical pulmonary artery (PA) dysplasia structures and different sizes of PDA was established. The three-element windkessel (3WK) multiscale coupling model was used to define boundary conditions for transient simulation through computational fluid dynamics (CFD). The results showed that the larger size of PDA led to a greater systemic-to-pulmonary shunt ratio (Q S/A), and the flow ratio of the left pulmonary artery (LPA) to right pulmonary artery (RPA) (Q L/R) was more close to 1, while both the proportion of high wall shear stress (WSS) areas and power loss decreased. The case of PDA nonclosure demonstrates that the aortic oxygen saturation (Sao2) increased, while the systemic oxygen delivery (Do2) decreased. In general, for the CS model with three typical PA dysplasia, the changing trends of hemodynamic parameters during the spontaneous closing process of PDA were roughly identical, and nonclosure of PDA had a series of hemodynamic advantages, but a larger PDA may cause excessive PA perfusion and was not conducive to reducing cyanosis symptoms.

Anterograde blood flow associated with modified Blalock-Taussig shunt does not modify pulmonary artery growth compared with modified Blalock-Taussig shunt alone.

BACKGROUND: The main difference between extreme tetralogy of Fallot (TOF) and pulmonary atresia with ventricle septal defect (PA/VSD) is anterograde pulmonary blood flow (APBF). It is speculated that the association of modified Blalock-Taussig shunt (mBTS) with APBF favours shunt thrombosis, but promotes better pulmonary artery growth. AIM: To compare pulmonary artery growth after mBTS between TOF and PA/VSD. METHODS: From 1995 to 2018, 77 mBTS procedures were performed in infants (aged<1 year): 45 for TOF; 32 for PA/VSD. Using a 1/1 propensity score-matched analysis, 38 patients were included (19 per group). Delta Nakata was defined as the difference in the Nakata index before biventricular repair and before mBTS. RESULTS: After matching, the preoperative Nakata index was similar in the two groups (TOF 101±34 vs. PA/VSD 106±35 mm2/m2; P=0.75). Age and weight were similar (TOF 24±20 days, 3.3±0.6kg vs. PA/VSD 24±33 days, 3.3±0.9kg; P=0.84 and P=0.77, respectively). There was no difference in rates of in-hospital mortality (TOF 0% vs. PA/VSD 10%; P=0.13) or mBTS thrombosis (TOF 15% vs. PA/VSD 10%; P=0.63). The left and right pulmonary artery diameters at time of biventricular repair were similar (TOF 7.5±2.2 and 6.7±2.1 vs. PA/VSD 8±2.7 and 7.1±2.5mm; P=0.43 and P=0.78, respectively), as were delta Nakata (TOF 112±102 vs. PA/VSD 107±66 mm2/m2; P=0.89), median age for biventricular repair (P=0.83) and reintervention rates (TOF 10% vs. PA/VSD 15%; P=0.67). CONCLUSIONS: We found no difference in pulmonary artery growth between APBF with mBTS versus mBTS alone. Thus, we could not show an increase in mBTS thrombosis with APBF.

Survival With Respect to Morphology in Pulmonary Atresia and Intact Ventricular Septum in Sweden.

BACKGROUND: Patients born with pulmonary atresia and intact ventricular septum represent a challenge to pediatric cardiologists. Our objective was to study changes in survival with respect to morphology in all children born with pulmonary atresia and intact ventricular septum in Sweden during 36 years. METHODS: A retrospective, descriptive study based on medical reports and echocardiographic examinations consisting of those born between 1980 and 1998 (early group) and those born between 1999 and 2016 (late group). RESULTS: The cohort consists of 171 patients (early group, n = 86 and late group, n = 85) yielding an incidence of 4.35 and 4.46 per 100,000 live births, respectively. One-year survival in the early group was 76% compared to 92% in the late group (P = .0004). For patients with membranous atresia, one-year survival increased from 78% to 98%, and for muscular pulmonary atresia, from 68% to 85%. In patients with muscular pulmonary atresia and ventriculocoronary arterial communications, there was no significant increase in survival. Risk factors for death were being born in the early time period hazard ratio (HR), 6; 95% CI (2.33-14.28) P = .0002, low birth weight HR, 1.26; 95% CI (1.14-1.4) P < .0001 and having muscular pulmonary atresia HR, 3.74; 95% CI (1.71-8.19) P = .0010. CONCLUSION: The incidence of pulmonary atresia and intact ventricular septum remained unchanged during the study period. Survival has improved, especially for patients with membranous pulmonary atresia, while being born with muscular pulmonary atresia is still a risk factor for death. To further improve survival, greater focus on patients with muscular pulmonary atresia and ventriculocoronary arterial communications is required.

Mid-Term Outcomes After Unifocalization Guided by Intraoperative Pulmonary Flow Study.

BACKGROUND: Repair of tetralogy of Fallot (TOF) with major aortopulmonary collateral arteries (MAPCAs) requires unifocalization of pulmonary circulation, intracardiac repair with the closure of the ventricular septal defect, and placement of a right ventricle (RV) to pulmonary artery (PA) conduit. The decision to perform complete repair is sometimes aided by an intraoperative flow study to estimate the total resistance of the reconstructed pulmonary circulation. METHODS: We reviewed patients who underwent unifocalization and PA reconstruction for TOF/MAPCAs to evaluate acute and mid-term outcomes after repair with and without flow studies and to characterize the relationship between PA pressure during the flow study and postrepair RV pressure. RESULTS: Among 579 patients who underwent unifocalization and PA reconstruction for TOF/MAPCAs, 99 (17%) had an intraoperative flow study during one (n = 91) or more (n = 8) operations to determine the suitability for a complete repair. There was a reasonably good correlation between mean PA pressure at 3 L/min/m2 during the flow study and postrepair RV pressure and RV:aortic pressure ratio. Acute and mid-term outcomes (median: 3.8 years) after complete repair in the flow study patients (n = 78) did not differ significantly from those in whom the flow study was not performed (n = 444). Furthermore, prior failed flow study was not associated with differences in outcome after subsequent intracardiac repair. CONCLUSIONS: The intraoperative flow study remains a useful adjunct for determining the suitability for complete repair in a subset of patients undergoing surgery for TOF/MAPCAs, as it is reasonably accurate for estimating postoperative PA pressure and serves as a reliable guide for the feasibility of single-stage complete repair.

Single-Cell Transcriptomics of Engineered Cardiac Tissues From Patient-Specific Induced Pluripotent Stem Cell-Derived Cardiomyocytes Reveals Abnormal Developmental Trajectory and Intrinsic Contractile Defects in Hypoplastic Right Heart Syndrome.

Background To understand the intrinsic cardiac developmental and functional abnormalities in pulmonary atresia with intact ventricular septum (PAIVS) free from effects secondary to anatomic defects, we performed and compared single-cell transcriptomic and phenotypic analyses of patient- and healthy subject-derived human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and engineered tissue models. Methods and Results We derived hiPSC lines from 3 patients with PAIVS and 3 healthy subjects and differentiated them into hiPSC-CMs, which were then bioengineered into the human cardiac anisotropic sheet and human cardiac tissue strip custom-designed for electrophysiological and contractile assessments, respectively. Single-cell RNA sequencing (scRNA-seq) of hiPSC-CMs, human cardiac anisotropic sheet, and human cardiac tissue strip was performed to examine the transcriptomic basis for any phenotypic abnormalities using pseudotime and differential expression analyses. Through pseudotime analysis, we demonstrated that bioengineered tissue constructs provide pro-maturational cues to hiPSC-CMs, although the maturation and development were attenuated in PAIVS hiPSC-CMs. Furthermore, reduced contractility and prolonged contractile kinetics were observed with PAIVS human cardiac tissue strips. Consistently, single-cell RNA sequencing of PAIVS human cardiac tissue strips and hiPSC-CMs exhibited diminished expression of cardiac contractile apparatus genes. By contrast, electrophysiological aberrancies were absent in PAIVS human cardiac anisotropic sheets. Conclusions Our findings were the first to reveal intrinsic abnormalities of cardiomyocyte development and function in PAIVS free from secondary effects. We conclude that hiPSC-derived engineered tissues offer a unique method for studying primary cardiac abnormalities and uncovering pathogenic mechanisms that underlie sporadic congenital heart diseases.

Major aortopulmonary collateral arteries in a case of unrepaired tricuspid and pulmonary atresia with single ventricle physiology.

Tricuspid and pulmonary atresia with single ventricle physiology and major aortopulmonary collateral arteries (MAPCAs) is a complex cyanotic congenital heart disease with heterogeneous pulmonary artery morphology and arborization. The complex anatomy and physiology, coupled with a dearth of existing literature, pose imitable challenges to treatment. Although the exact surgical algorithm is still unclear, the goal is a well-developed, low-resistance pulmonary vascular bed. A precise understanding of the blood supply to each lung is a requisite for successful surgery, and a multimodality and multidisciplinary approach is compulsory. Herein, we describe a case of tricuspid and pulmonary atresia with single ventricle, MAPCAs and aortopulmonary collateral arteries.

Ventricular Septal Defect Pulmonary Atresia: Provisional Bifurcation Strategy for Confluence Stenosis During Patent Ductus Arteriosis Stenting.

Neonates with pulmonary atresia survive only if duct patency is maintained before staged surgical repair. Ductal stenting is an effective alternative to conventional shunt surgery, as it avoids thoracotomy. With today's generation of coronary stents having better profile, flexibility, and trackability, it may be achieved safely, with less difficulty than previously described. The strategy during patent ductus arteriosus (PDA) stenting with trifurcation narrowing is a real challenge. We present an underweight newborn with ventricular septal defect pulmonary atresia, restrictive PDA, and bilateral branch stenosis at the ostia. We performed a successful PDA stenting as well as addressed the ostia of branch pulmonary arteries.

Pregnancy in non-palliated functionally single ventricle: challenges of management in resource-poor settings.

Women with complex functionally univentricular hearts rarely survive into adulthood without corrective or palliative surgery. Reports of pregnancy outcome in this group of patients in resource-poor settings are sparse. We report a case of unrepaired pulmonary atresia ventricular septal defect (VSD) with major aorto-pulmonary collateral arteries (MAPCA) who survived into adulthood and was able to complete a successful pregnancy in a resource-poor country.

Fetal cardiac interventions: Where do we stand?

Fetal cardiac intervention (FCI) is a novel and evolving technique that allows for in utero treatment of a subset of congenital heart disease. This review describes the rationale, selection criteria, technical features, and current outcomes for the three most commonly performed FCI: fetal aortic stenosis with evolving hypoplastic left heart syndrome (HLHS); HLHS with intact or restrictive atrial septum; and pulmonary atresia with intact ventricular septum, with concern for worsening right ventricular (RV) hypoplasia.

Pulmonary Atresia with Ventricular Septal Defect: Rare Presentation with Coronary-to-Pulmonary Artery Collaterals from Both Right and Left Coronaries.

Pulmonary atresia with ventricular septal defect and coronary-dependent pulmonary circulation arising from both major coronary arteries is rare. Dependence of pulmonary blood flow on the coronaries and the risk of early development of pulmonary vascular obstructive disease warrant early surgical repair in these patients. We report a case of a ten-month-old infant with pulmonary atresia with ventricular septal defect and coronary artery-to-main pulmonary artery connections who was successfully managed with ligation of the coronary fistulas and intracardiac repair.

Right Ventricle-Dependent Coronary Circulation: Location of Obstruction Is Associated With Survival.

BACKGROUND: Pulmonary atresia with intact ventricular septum (PAIVS) with right ventricle-dependent coronary circulation (RVDCC) carries suboptimal outcomes primarily due to cardiac ischemia. We hypothesize clinical outcomes are affected by the level of coronary obstruction, a surrogate for vulnerable myocardium. METHODS: We conducted a single-institution retrospective analysis of all neonates with PAIVS with RVDCC from 1995 to 2017. RVDCC was defined as the presence of any coronary-cameral fistula with coronary obstruction proximal to the fistula and angiographic evidence of RV perfusion of the myocardium through the fistulous communication. Location of coronary obstruction was categorized as either proximal or distal segments, using the SYNTAX score criteria. Transplant-free survival was compared between patients with proximal and distal obstruction, then these groups were compared with patients without RVDCC. RESULTS: Of 103 neonates with PAIVS, 28 (27%) had RVDCC: 18 proximal (64%), 10 distal (36%). Median age at last follow-up for patients with RVDCC was 1.8 years (interquartile range, 0.3-8.1 years). All deaths (10 of 28, 36%) occurred at 6 months old or earlier. Proximal coronary artery obstruction was associated with decreased transplant-free survival relative to distal obstruction (hazard ratio = 3.63; 95% confidence interval, 1.01-13.00; P = .048). Transplant-free survival at 1 year was 33% and 70% in the proximal and distal obstruction groups, respectively. Compared with patients without RVDCC, patients with proximal obstruction had significantly lower transplant-free survival (P < .001), whereas patients with distal obstruction did not (P = .217). CONCLUSIONS: The location of coronary artery obstruction affects clinical outcome and may represent a potential branch point in the management for PAIVS with RVDCC.

Percutaneous obliteration of the right ventricle to avoid coronary damage by sinusoids in patients with pulmonary atresia intact ventricular septum during staged single ventricle palliation.

BACKGROUND AND AIMS: Suprasystemic pressure waves can damage the coronary arteries resulting in myocardial ischemia and excess early mortality. We aimed to reduce the coronary pressure wave through the sinusoids by abolishing RV volume with percutaneous devices. METHODS AND RESULTS: Four patients with PA-IVS and coronary sinusoids from the hypertensive rudimentary RV were evaluated at a median age 26.6 months (range: 2.7-51.7). Right ventricle coronary dependent flow to the left ventricular myocardium was excluded. All four patients had dual perfusion with competitive flow from the RV through the sinusoids to the coronary arteries. Devices used were: Amplatzer vascular plug II of 10-16 mm; 27 coils (diameter 5-15 mm) in the oldest patient. Right ventricular angiography after cavity obliteration showed no more significant coronary perfusion through the sinusoids. There were no complications or deaths. Only minor and transient changes in the levels of troponin were observed. Coronary angiography at pre-Fontan evaluation showed no progress of coronary abnormalities in two patients. CONCLUSION: In selected patients with functionally single left ventricle, obliteration of the hypertensive RV cavity by percutaneous devices is safe and abolishes the systolic pressure wave in coronary sinusoids. When performed early, this may halt coronary damage and avoid excess mortality.

Fetal pulmonary atresia with ventricular septal defect: Features, associations, and outcome in fetuses with different pulmonary circulation supply types.

OBJECTIVES: To assess features and outcome in fetuses with pulmonary atresia with ventricular septal defect (PA-VSD). METHODS: Fetuses with PA-VSD were prospectively enrolled and grouped on the basis of the pulmonary blood supply, including type A (only arterial duct [DA]), type B (both DA and major aortopulmonary collateral arteries [MAPCAs] present), and type C (MAPCAs only). The echocardiography features, associated chromosomal/genetic malformations, and postnatal outcome were compared among the three groups. RESULTS: Fifty-five fetuses with PA-VSD were enrolled. The presence of confluent PAs varied, with the highest displaying rate in type A and lowest rate in type C (100% vs 41.1%). The intrapericardial pulmonary arteries in all groups were hypoplastic but smaller in types B and C than in type A (P < .05). Deletion of 22q11.2 and right aortic arch were more frequently observed in types B and C than in type A. At the end of the study, overall survival rates in type C were lower than those in type A (22.1% vs 77.3%). CONCLUSION: There are great differences in the size of pulmonary arteries, associated genetic malformations, and perinatal outcomes among fetuses with PA-VSD. These results could be used for family counseling and surgical planning.

Mid-Term Outcome of Right Ventricle to Pulmonary Artery Shunt for Older Children and Young Adults With Ventricular Septal Defect, Pulmonary Atresia, and Hypoplastic Pulmonary Arteries.

Management strategy for patients of ventricular septal defect and pulmonary atresia (VSD/PA) with hypoplastic pulmonary arteries presenting in late childhood or adolescence is still controversial. We present our experience with the use of right ventricle-pulmonary artery shunt (RV-PA) in management of this entity. Between January 2014 and April 2018, 25 patients of VSD/PA underwent valveless RV-PA shunt at our center. The size of the RV to PA shunt was calculated as half the expected diameter of the main pulmonary artery. We retrospectively reviewed the data from hospital records. Follow-up data were recorded from outpatient records or via telephone. Mean age of the cohort was 12.25 ± 3.18 years. There was 1 early and 1 interstage mortality. None of the patient developed acute renal failure, ventricular dysfunction, and arrhythmias. At interstage follow-up of 8.28 ± 3.7 months, both Nakata index (from 66.23 ± 24.12 to 185.8 ± 58 mm2/m2) and McGoon ratio (0.9 ± 0.22 vs 49 1.84 ± 0.4) increased significantly compared to preoperative value, whereas RPA-LPA ratio was not significantly changed (1.095 ± 0.39 vs 1.01 ± 0.56, P = 0.63). Prerepair pulmonary vascular resistance in 17 patients, who underwent complete repair, was 2.9 ± 0.69 woods unit/m2. Postrepair right ventricle-left ventricle pressure ratio was 0.5 ± 0.14. There was no early or late mortality and none of the patient required conduit revision or VSD fenestration. On follow-up of 25.75 ± 17.94 months, 16 patients were in NYHA I and 1 patient was in NYHA II. Appropriate-sized RV-PA shunt is an effective strategy for achieving balanced pulmonary artery growth in VSD/PA with hypoplastic pulmonary arteries presenting late without the risk of pulmonary over circulation or systemic malperfusion.

Right ventricular function in patients with pulmonary regurgitation with versus without tetralogy of Fallot.

BACKGROUND: Right ventricular (RV) dilation from pulmonary valve regurgitation (PR) is common after intervention(s) for pulmonary stenosis (PS) or atresia and intact ventricular septum (PA/IVS). It is not well established whether PR and RV dilation have similar effects on RV function and exercise capacity in these patients compared to patients after repair of tetralogy of Fallot (rToF). The aims of this study were to compare exercise tolerance, RV function and myocardial mechanics in non-ToF versus rToF children with significantly increased and comparable RV volumes. METHODS: Thirty PS or PA/IVS children after intervention(s) with significant PR and RV dilation (non-ToF group) were retrospectively matched for RV end-diastolic volume index (RVEDVi) and age with 30 rToF patients. Clinical characteristics, RV function by echocardiography and CMR, ECG and exercise capacity were compared between groups. RESULTS: The groups were well matched for RVEDVi and age. Global RV function (RVEF: 48.7 ±â€¯6.4% vs. 48.5 ±â€¯7.2%, P = .81) and exercise capacity (% predicted peak VO2:82.5 ±â€¯17.7% vs. 75.6 ±â€¯20.4%, P = .27) were similarly reduced between groups. RVEDVi correlated inversely with RVEF in both groups (non-ToF:r = -0.39, P = .04, rToF:r = -0.40, P = .03). QRS duration was wider in rToF patients, and in both groups inversely correlated with RVEF (non-ToF:r = -0.77, P < .001, rToF:r = -0.69, P < .001). In contrast to global function, longitudinal RV strain was lower in rTOF vs non-TOF (-20.1 ±â€¯3.9 vs.-25.7 ±â€¯4.4, P < .001). CONCLUSIONS: Global RV function and exercise capacity are similarly reduced in non-ToF and rToF patients with severely dilated RV, after matching by RVEDVi, suggesting a comparable impact of RV dilation on RV global function. The significance of reduced RV longitudinal function and worse dyssynchrony in rToF patients require further exploration.

Measurement of Residual Collateral Flow in Pulmonary Atresia With Major Aortopulmonary Collaterals.

BACKGROUND: Pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (MAPCAs) is a rare form of congenital heart disease characterized by the entirety of pulmonary blood flow originating from systemic vessels. This study measured the residual collateral flow after harvesting of the MAPCAs for surgical repair. METHODS: The study enrolled 32 patients with pulmonary atresia with ventricular septal defect and MAPCAs who were undergoing their first surgical procedure. The median age was 6.8 months, and median weight was 5.7 kg. The patients had a mean of 4.2 ± 0.7 MAPCAs. The cardiopulmonary bypass circuit was modified to contain a diversion loop in the left ventricular vent system to accurately measure residual collateral flow. During the period of aortic cross-clamp (for ventricular septal defect repair), the diversion loop was opened for 1-minute intervals, and the residual collateral flow collected. The systemic perfusion temperature was 25° and flow rate was 100 mL · kg-1 · min-1. RESULTS: The mean residual collateral flow was 5.5 mL · kg-1 · min-1 (range, 0.8 to 15.2 mL · kg-1 · min-1). The corresponding calculated pulmonary blood flow-to-systemic blood flow ratio values ranged from 1.01 to 1.36. There was a significant correlation between residual collateral flow and preoperative saturation (p < 0.05). CONCLUSIONS: The data demonstrate a wide range of residual collateral flow values after harvesting of the MAPCAs. The amount of residual collateral flow was correlated with preoperative saturation. These results suggest that some patients at the higher end of this spectrum may require adjustments in pump flow to assure adequate systemic perfusion.