Truncal or aortic valve stenosis in functionally single arterial trunk: A clinical,hemodynamic and pathologic study of six cases

Stenosis of the semilunar valve in the presence of a functionally single arterial trunk is uncommon. Three patients with truncus arteriosus, two with tetralogy of Fallot and pulmonary atresia and one with pulmonary atresia and intact septum were diagnosed as having stenosis of the truncal or aortic valve on the basis of clinical, echocardiographic, hemodynamic and angiocardiographic findings. Echocardiograms consistently showed multiple diastolic closure lines and abnormal semilunar valves in addition to the aortic override in five patients and hypoplastic right ventricle in the patient with pulmonary atresia and intact septum. Peak systolic gradients between the left ventricle and truncus (or aorta) at cardiac catheterization ranged from 20 to 47 mm Hg. Retrograde aortography confirmed a domed and stenotic semilunar valve. Cyanosis was progressive in the three patients with pulmonary atresia. Two patients had arterial anastomosis, and one had a right ventricle-pulmonary arterial graft in addition to aortic valvotomy. One of the three patients with truncus arteriosus underwent complete repair in addition to truncal valvotomy but he died in the postoperative period. The other two patients with truncus arteriosus died of intractable congestive cardiac failure before surgical intervention.It is suggested that the presence of semilunar valve stenosis in these patients adversely affects the prognosis. The myocardium is already jeopardized as a result of hypoxia in pulmonary atresia and left ventricular diastolic overload in patients with truncus arteriosus. The added burden of semilunar valve stenosis may further compromise the functional status of the myocardium.     

Two dimensional echocardiographic assessment of communications between ascending aorta and pulmonary trunk or individual pulmonary arteries.

The value of two dimensional echocardiography in identifying communications between the ascending aorta and pulmonary trunk or individual pulmonary arteries was assessed in 24 children, all of whom had either angiocardiographic and surgical or angiocardiographic confirmation alone. Fourteen cases had truncus arteriosus, four aortopulmonary window, four anomalous origin of the left pulmonary artery from the ascending aorta, and two anomalous origin of the right pulmonary artery from the ascending aorta. It was possible to identify reliably each individual abnormality with a combination of suprasternal, precordial, and subcostal cuts. Problems only arose in differentiating truncus arteriosus from pulmonary atresia and ventricular septal defect when the main pulmonary artery and infundibular region of the right ventricle were extremely hypoplastic.     

Truncus arteriosus malformation: a spectrum including fourth and sixth aortic arch interruptions

Previous explanations of the pathogenesis of truncus arteriosus malformation have emphasized absence of conotruncal ridges, absence of pulmonary conus, or fusion of ventricular outflow streams. These concepts explain the persistence of the single semilunar valve and outflow vessel, but have not elucidated the significance of many associated anatomic lesions. We studied the 19 patients with truncus arteriosus malformation listed in the autopsy files of The Johns Hopkins Hospital whose hearts were available for review. The patients ranged in age from one day to 30 years, and included 12 males. All hearts showed a single semilunar valve with three or four cusps, and a high ventricular septal defect. In 13 patients, the aorta was larger in diameter than the pulmonary artery, and no remnant of the ductus arteriosus was present (interruption of the embryonic sixth arch). In one patient, the aorta was larger than the pulmonary artery, and a small, patent ductus arteriosus was present. In two patients, the pulmonary artery was larger than the aorta, and the aortic arch was interrupted. The remaining three cases could not be fully evaluated for the status of the ductus arteriosus and size of the great arteries. We tabulated the number of associated anatomic lesions which were unexplained by each of the three pathogenetic hypotheses. The fused outflow stream hypothesis, which explains truncus arteriosus malformation as the result of a maldirection of ventricular outflow streams so that the separation of two semilunar valves is prevented, was superior at the 0.05 level of significance. This concept explains the spectrum of great vessel patterns in which flow is dominant into either the sixth or fourth embryonic aortic arch, permitting early disappearance of unperfused segments of the aortic arches, and is commonly seen at autopsy as either an interrupted aorta or an absent ductus arteriosus.     

Echo-phonocardiographic and contrast studies in conditions associated with systemic arterial trunk overriding the ventricular septum: truncus arteriosus, tetralogy of Fallot, and pulmonary atresia with ventricular septal defect.

Echocardiography was performed in 62 patients--20 with truncus arteriosus, 14 with tetralogy of Fallot, and 28 with pulmonary atresia with ventricular septal defect. Features common in all three groups were: large single systemic arterial trunk overriding the ventricular septum, mitral-semilunar continuity, large right ventricular dimension, and normal septal motion. Indocyanine green contrast flow patterns were similar and were most helpful in detecting an associated atrial septal defect and in studying the timing and pattern of right-to-left shunting. Echo-phonocardiographic studies revealed that the ejection click coincided with the point of maximal opening of aortic or truncal valve. Left atrial dimension was measured in 55 patients and was normal or small in 41 patients and large in 14 patients. Our observations indicate that left atrial dimension provides a good index of pulmonary flow and can help differentiate those patients with increased pulmonary flow and can help differentiate those patients with increased pulmonary flow (truncus arteriosus) from those patients with reduced pulmonary flow (tetralogy of Fallot and pulmonary atresia with associated ventricular septal defect).     

Truncus arteriosus communis with intact ventricular septum.

This is the first documented case of truncus arteriosus communis with intact ventricular septum in which extensive clinical, haemodynamic, angiographic, and pathological data are available. Angiography suggested the presence of two discrete semilunar valves but necropsy showed a basically single semilunar valve. This case fills a gap in the spectrum of aorticopulmonary, truncal, and infundibular septal defects, and reinforces the belief that the essence of truncus arteriosus communis is a single semilunar valve, common to both ventricles, which need not be associated with the defects in the adjacent parts of the structural continuum.     

Interrupted aortic arch--anatomical features of surgical significance

Analysis of 26 autopsy specimens with interruption of the aortic arch has led to a clearer understanding of the vital importance of associated cardiovascular abnormalities. In all cases there was an associated patent ductus arteriosus "supporting" the distal systemic circulation. "Proximal" septal defects, 22 ventricular septal defects and 3 aorto-pulmonary windows, were found in all but one specimen. The infundibular component of the ventricular septum was displaced posteriorly and leftward in 9 hearts resulting in significant left ventricular outflow obstruction in 8. In one specimen the infundibular septum was displaced anteriorly giving the effect of a "Fallot type" obstruction to the right ventricular outflow tract. Abnormal ventriculo-arterial connections were found in 7 hearts; 2 with discordant connection, 2 with double outlet, and 3 with single outlet of the heart. In 6 specimens there was an aberrant origin of the right subclavian from the distal aorta passing behind the esophagus to the right side. Various other arterial abnormalities were identified including a truncus arteriosus with separate but "transposed" origins of the pulmonary arteries. In short, in these hearts there were no examples of the rare situation where aortic arch interruption exists in isolation. This study therefore makes it very clear that a detailed understanding of associated anatomical abnormalities must accompany any attempt at surgical correction. Certainly in many of these cases management of the associated lesion will present more of a challenge than the difficult problem of dealing with the interrupted arch itself.     

Association of interrupted aortic arch with malformations producing reduced blood flow to the fourth aortic arches

Interrupted aortic arch is a rare congenital malformation of the great arteries with loss of continuity between the proximal portion of the aortic arch and the descending aorta, which is usually supplied by a patent ductus arteriosus. The hearts of 12 patients with interrupted aortic arch listed in the autopsy files of The Johns Hopkins Hospital were evaluated. Four categories were identified. Seven hearts with normal outflow tract relations had significant pulmonary arterial override of a ventricular septal defect and thus received part of left ventricular and all of right ventricular ejection flow; flow into the aorta was correspondingly reduced. Two hearts had mitral valve obstruction with decreased left heart flow. Two hearts had double inlet left ventricle and transposed great arteries with the aorta originating from a small anterior conal chamber. One heart had a truncus malformation with a disproportionately large flow entering the pulmonary arterial division. In each of these hearts, the pattern of the outflow tracts and associated malformations suggested that there was a preferential flow of blood into the sixth arches and correspondingly a reduced flow Into the fourth arches at the time of normal disappearance of components of the embryonic aortic arch system. Thus, interrupted aortic arch may simply be disappearance of the normally persisting connection between the left fourth and sixth arches as a result of flow imbalance in early cardiogenesis.     

Truncus arteriosus. An anatomical-angiographic study.

A series of 25 cases of truncus arteriosus communis examined post mortem was studied retrospectively. Fifteen of them had had angiographic studies, enabling anatomo-radiographic correlative analysis to be made. All cases had situs solitus of the atria and concordant connections between atria and ventricles. The three main components of the malformation, present in all 25 cases, were: (a) ventricular septal defect, (b) single semilunar valve, (c) anomalies of the aortopulmonary septum. The ventricular septal defect was always subarterial but its size and its relation to mitral and tricuspid valves were extremely variable. The truncal valve varied greatly also in the number of its cusps and its relation to right and left ventricles. Above valvular level the presence or absence of residual aortopulmonary septum was reflected by the presence or absence of a main pulmonary artery. Additional supratruncal malformations produced variations of the anatomy of the aorta and pulmonary arteries. The angiographic demonstration of all these components was obtained best by selective angiography using special projections. From this study it appears that there is a wide degree of variability in all of the three main components of truncus arteriosus. Such anatomical variations should be identified angiographically in each patient in order to provide enough information before corrective surgery, but they do not alter the basically homogeneous anatomy of the category of truncus arteriosus and therefore do not justify complex classifications.     

Two-dimensional echocardiographic prospective diagnosis of common truncus arteriosus in infants

Two-dimensional echocardiographic prospective diagnosis of truncus arteriosus was made in 7 infants. Two infants had truncus arteriosus type I, 3 patients had truncus arteriosus type II, 1 infant had truncal valve stenosis with an interrupted aortic arch, and 1 had type IV truncus arteriosus with pulmonary hypertension. Multiple imaging views were utilized to confirm the diagnosis. The parasternal long-axis view demonstrated the great vessel-ventricular septal override and the origin of the pulmonary arteries from the posterior aspect of the ascending truncus. The suprasternal notch image facilitated identification of the left- or right-sided aortic arch and the origin of the pulmonary arteries from the truncus. Transverse imaging sections at the base of the heart facilitated identification of the pulmonary artery origin of truncus arteriosus type I. Subcostal coronal and sagittal views imaged the common truncus and the ventricular septal defect.

These echocardiographic images were contrasted with and discriminated from those of an infant with aorticopulmonary window with intact ventricular septum. Although cardiac catheterization and angiography may be required to assess pulmonary arterial pressure, pulmonary vascular resistance, and the distal pulmonary arterial anatomy in truncus arteriosus, 2-dimensional echocardiography can be used to correctly establish the morphologic diagnosis of truncus arteriosus in infants.     

Fetal cardiovascular morphology of truncus arteriosus with or without truncal valve insufficiency in the rat

BACKGROUND. Recent advances in fetal echocardiography have necessitated further study on fetal in situ cardiovascular morphology of truncus arteriosus and the effects of truncal valve insufficiency. METHODS AND RESULTS. We studied 55 fetal rats with truncus arteriosus among 300 fetuses from 40 virgin females treated with 200 mg fertilysin on the 10th day of pregnancy. After rapid whole-body freezing on the 21st day, the fetuses were studied by means of serial cross-sectional photographs of the frozen thorax. Thirty-five fetuses with a normal heart treated with fertilysin served as controls. Truncus arteriosus was characterized by a large ventricular septal defect, a solitary artery (truncus arteriosus) overriding the ventricular septum, the right and left pulmonary arteries originating from the truncus arteriosus with or without a common trunk (main pulmonary artery), and absent ductus arteriosus. Fetuses with truncal valve insufficiency had thick truncal valves, a large truncus arteriosus, and large ventricles. The subgroup of 12 fetuses with a large truncus (truncal diameter greater than 160% of the ascending aorta diameter in the controls) showed significantly greater values for right ventricular volume (200% of control) and mass (120% of control), left ventricular volume (170% of control) and mass (110% of control), right (120% of control) and left (110% of control) atrial volume, and pericardial fluid (140% of control) than the controls. These changes were less prominent and ventricular volumes were not increased in the remaining subgroup with a truncal diameter of 160% or less of aorta diameter in the controls. CONCLUSIONS. In fetal truncus arteriosus, truncal valve insufficiency was associated with increased ventricular volume load and incomplete cardiac compensation in rats.     

Two-dimensional echocardiographic study of right ventricular outflow and great artery anatomy in pulmonary atresia with ventricular septal defects and in truncus arteriosus

In this study, we reviewed M-mode and two-dimensional (2DE) echocardiographic observations in 13 patients with pulmonary atresia with ventricular septal defect and in six patients with truncus arteriosus in order to attempt to identify echocardiographic features distinguishing these two abnormalities in which no anatomic connection exists between the right ventricle and the pulmonary artery. M-mode features compatible with the diagnosis of pulmonary atresia with a ventricular septal defect (VSD) were a small but identifiable space anterior to the aorta and/or immobile pulmonic valve echoes appearing to open during diastole rather than systole. By 2DE, the proximal and distal segments of the right ventricular outflow tract could be imaged and the length of the atretic segment estimated. In truncus arteriosus, no outflow tract of the right ventricle could be identified by 2DE or M-mode echocardiography, and the origin of the pulmonary artery from the truncus could be imaged directly in four patients with type I and in one patient with type II truncus. Abnormalities of the truncal valve were also present and were imaged by 2DE in three of our five patients. Our study identified specific echocardiographic criteria for diagnosing truncus arteriosus and pulmonary atresia with VSD and for differentiation between them.     

Persistent common trunk. Anatamopathological study of 25 specimen]

In order to inform the pathologic features and their associated anomalies twenty five hearts with common trunk were studied with the segmental sequential system. An anatomico-embryological correlation was made to understand the pathological complex of this malformation. The results were: type I truncus (96%), infundibular ventricular septal defect (96%), displastic truncal valve (28%), ventriculo infundibular fold (92%), left coronary artery arising from the posterior wall of the truncus (75%), right coronary artery arising from their anterior wall (96%), coronary arteries arising from opposite Valsalva sinuses in the tetracuspid valves; the biventricular conection of the truncus was balanced in 60%, prevailing on the right (16%) or on the left (16%) ventricles. Among the associated anomalies there were right aortic arch, interruption of the aortic arch, anomalous origin of the left subclavian artery, vascular ring, aneurysm of the sinus of Valsalva, and absence of the left branch of the pulmonary artery. Developmentally common trunk is explained as a failure of truncoconal septation in the embryonic heart; a migration arrest of neural crest cells is implicated in the Di George syndrome. Knowledge of the anatomic features of common trunk and their associated anomalies, provides the morphological basis to interpret correctly the clinical diagnostic imagenology.     

Pathogenesis of persistent truncus arteriosus in light of observations made in a dog embryo with the anomaly

Among 36 embryos obtained from a strain of Keeshond dogs in which there is a large incidence of spontaneously occurring conotruncal anomalies, a specimen with persistent truncus arteriosus, type 1 was found. The embryo had a crown-rump length of 20 mm. The specimen was serially sectioned and a wax plate reconstruction was made of the heart and proximal great vessels at a magnification of X100. The truncal valve was quadricuspid and dysplastic; associated anomalies were a right subclavian artery arising anomalously from the descending aorta, a single coronary artery, an absent ductus arteriosus and a small persistent left cranial (superior) vena cava. The truncus cushions were hypoplastic, had failed to fuse and each had simply produced an arterial cusp. The observations made on this embryo support the view that in persistent truncus arteriosus there is failure of septation of the truncus arteriosus. No evidence was found in favor of the concept that persistent truncus arteriosus represents a form of tetralogy of Fallot with atresia of the subpulmonary infundibulum and partial or complete absence of the aorticopulmonary septum.     

Histology of pulmonary arterial supply in pulmonary atresia with ventricular septal defect.

A histologic study was performed on 22 specimens of pulmonary atresia with ventricular septal defect to 1) ascertain the existence of the main pulmonary artery; 2) distinguish the ductus arteriosus from the systemic collateral arteries (SCA); 3) establish the nutritive or functional nature of collateral circulation; and 4) evaluate the morphology of the distal pulmonary bed. Three cases had absent main pulmonary artery, one with and two without signs of infundibular septation. We suggest that absent main pulmonary artery may exist with both infundibular pulmonary atresia and persistent truncus arteriosus. SCAs have been found to have similar histological features as systemic muscular arteries of the same size--their medial muscular layer merges gradually into an elastic one at different depth inside the lungs. Injection of contrast material allowed us to demonstrate that these vessels are functional, since they inosculate into efficient pulmonary arteries ending in the respiratory units. When the distal pulmonary vascular bed is perfused by large SCAs, proliferative lesions like those found in large left-to-right shunts may occur. Early in infancy, banding of large, nonstenotic SCAs could protect the distal pulmonary vasculature. Moreover, total surgical repair should be associated with ligation of the SCA to avoid residual left-to-right shunt, if the pulmonary arteries can carry the full pulmonary blood flow.     

Absent pulmonary valve or pulmonary atresia with intact ventricular septum: Which is it?

A fetal echocardiogram noted valvar pulmonary atresia vs critical pulmonary valve stenosis, confluent pulmonary arteries, patent ductus arteriosus, and an apical muscular ventricular septal defect vs coronary sinusoid. Postnatal echocardiogram documented an absent pulmonary valve, coronary artery fistula to the right ventricle, confluent pulmonary arteries, and a patent ductus arteriosus. Catheterization confirmed the postnatal echocardiographic findings except there was no antegrade flow from the right ventricle to the pulmonary arteries. Close evaluation of all imaging modalities revealed the final diagnosis of absent pulmonary valve with a double-chambered right ventricle with no egress from the right ventricle to pulmonary artery.     

Truncus arteriosus with anterior origin of a hypoplastic main pulmonary artery

A newborn with an unusual form of truncus arteriosus is described, whose clinical presentation and certain features of her anatomy were more typical of pulmonary atresia with a ventricular septal defect. The morphological differentiation of certain types of truncus arteriosus and pulmonary atresia with ventricular septal defect remains an area of speculation among cardiac pathologists, and research in this area is being done using animal models. The anatomic features of the heart described in this report may assist in this discussion as the application of observations made in animal models to human cardiac development may be problematic.

Keywords: congenital heart disease;  truncus arteriosus;  echocardiography     

Stenotic semilunar valve in persistent truncus arteriosus.

The clinical, hemodynamic, and pathologic findings in two newborn infants with persistent truncus arteriosus and stenosis of the truncal valve are described. In one case the anatomic features of the basic condition were classic, with a dysplastic semilunar valve which was mainly stenotic and also incompetent, while in the other the truncus arteriosus arose exclusively from the right ventricle and was almost exclusively stenotic. A ventricular septal defect was the only outlet for the left ventricle. In this case, mitral stenosis was also present and associated with a left-to-right shunt at the atrial level.     

Eisenmenger syndrome in adults: ventricular septal defect, truncus arteriosus, univentricular heart.

OBJECTIVES: Morbidity and mortality patterns were characterized in adults with the Eisenmenger syndrome when two ventricles with a ventricular septal defect (VSD) joined two great arteries or one great artery, or when one ventricle joined two great arteries. BACKGROUND: Although afterload in these disorders differs, clinical differences have not been defined. METHODS: Seventy-seven patients were studied. Group A comprised 47 patients with VSD, aged 23 to 69 years (mean 39.5+/-10.2), follow-up 5 to 18 years (mean 7.2+/-4.9); group B, 14 patients with truncus arteriosus, aged 27 to 50 years (mean 33.7+/-7.3), follow-up 6 to 18 years (mean 7.7+/-5.1), and group C, 16 patients with univentricular heart, aged 18 to 44 years (mean 30.6+/-8.4), follow-up 5 to 15 years (mean 4.4+/-4.2). Echocardiography established the diagnoses and anatomic and hemodynamic features. Data were compiled on tachyarrhythmias, pregnancy, infective endocarditis, noncardiac surgery and the multisystem disorders of cyanotic adults. RESULTS: Thirty-five percent of the patients died. Sixty-three percent of deaths were sudden, and resulted from intrapulmonary hemorrhage, rupture of either the pulmonary trunk, ascending aorta or a bronchial artery, or vasospastic cerebral infarction, or the cause was unestablished. There were no documented tachyarrhythmic sudden deaths. CONCLUSIONS: Medical management of coexisting cardiac disease, multisystem systemic disorders, noncardiac surgery and pregnancy has reduced morbidity. Increased longevity exposed patients to proximal pulmonary arterial aneurysms, thromboses and calcification; to truncal valve stenosis and regurgitation; to semilunar and atrioventricular valve regurgitation, and to major risks of nontachyarrhythmic sudden death.     

Atresia of the right atrioventricular orifice.

The results are reported of a study of 83 necropsied hearts with atresia of the right atrioventricular orifice. It is emphasised that right atrial or atrioventricular orificial atresia is a better term to describe this anomaly than "tricuspid atresia". Use of the latter term can be confusing when the morphologically tricuspid valve is located beneath the left atrium. It is accepted that the definition employed may include cases in which the mitral valve may be atretic, blocking normal exit from the right atrium, but it is argued that such cases would present clinically as "tricuspid atresia" and therefore are correctly designated as right atrial orificial atresia. The results show that the majority of hearts with right atrial orificial atresia have the ventricular morphology of primitive ventricle, most with, but a few without an outlet chamber. However, in a minority of hearts an imperforate membrane interposes between the right atrium and a formed but hypoplastic right ventricle. In two of the hearts, the imperforate membrane showed features of Ebstein''s malformation. The hearts could be further subdivided according to the ventriculoarterial connection. Most had normally connected arteries (66 of 83), and all but 2 also had normal relations between the arteries; in these 2 hearts there was "anatomically corrected malposition". Twelve hearts showed transposition, one had double-outlet outlet chamber, and another persistent truncus arteriosus. The remaining 3 hearts, all without outlet chamber, had by definition a double outlet connection. A segmental approach provides the best way of classifying this anomaly, and an embryological explanation is offered for the variations in anatomy observed.