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.     

Persistent truncus arteriosus: A study of 66 autopsy cases with special reference to definition and morphogenesis

Sixty-six hearts were examined in which a single arterial trunk, leaving the base of the heart through a single semilunar valve, supplied the aorta, pulmonary artery and coronary arteries. Careful attention was paid to the infundibular morphologic features in these hearts, and these were compared with findings in 24 hearts with single aortic trunk, pulmonary atresia and ventricular septal defect. It was concluded that the two anomalies represented morphologically discrete conditions. This was particularly true with regard to the disposition of the infundibular septum, the ventriculo-infundibular fold and the relation of the coronary arteries to the semilunar sinuses. Although it is theoretically possible for a heart with true persistent truncus arteriosus to have absence of the pulmonary trunk and right and left pulmonary arteries, it is argued that such hearts (“truncus type IV”) are best classified as pulmonary atresia with ventricular septal defect. It is also argued that hearts with a common arterial trunk supplied through discrete ventricular outflow tracts and two semilunar valves are best considered examples of aorticopulmonary window. It is suggested that persistent truncus arteriosus is best defined as that condition in which a single arterial trunk leaves the heart through a single semilunar valve and supplies the aorta, one or both pulmonary arteries and the coronary arteries.     

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.     

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.     

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 features of interruption of the aortic arch

The 2-dimensional echocardiographic features of interruption of the aortic arch are presented based on analysis of the echocardiograms and angiograms from 8 infants: 2 with type A and 6 with type B interruption. Each infant had a patent ductus arteriosus, 6 had a conoventricular septal defect with leftward deviation of the conal septum, 1 had truncus arteriosus with truncal valve stenosis, and 1 had a distal aortopulmonary septal defect with an intact ventricular septum. Echocardiographic images obtained from the suprasternal notch or from a high parasternal approach demonstrated the interruption of the aortic arch and continuation of the patent ductus arteriosus into the descending aorta. These findings were compared with those in infants with aortic atresia and a hypoplastic ascending aorta or discrete coarctation of the aorta with tubular hypoplasia of the aortic arch. Types A and B interruption of the aortic arch were easily differentiated and the caliber of the patent ductus arteriosus was assessed. The characteristic conoventricular septal defect was readily visualized from an apex 2-chamber view or from a subcostal sagittal plane view. With this information subsequent angiography can be more expeditiously performed in this group of critically ill infants.     

Echocardiographic features of truncal abnormalities. Special emphasis to the evaluation of pulmonary arteries

9 patients with persistent truncus arteriosus, 11 patients with pseudotruncus and 2 patients with hemitruncus, ranging in age from 6 months to 29 years, have been studied by M-mode and two-dimensional echocardiography (2-D echo). In all patients the diagnosis was confirmed by cardiac catheterization and angiocardiography; in 10 of them surgical or autopsy documentation was available. Peripheral contrast echocardiography was performed in 13 patients. A variable degree of truncal or aortic override was observed in 7 of 9 patients with truncus arteriosus and in all patients with pseudotruncus by M-mode or two-dimensional echocardiography. By 2-D echo the truncal origin of the right and left pulmonary arteries was visualized in 7 of 9 of the patients with truncus arteriosus. Visualization of one aberrant pulmonary artery from the aortic wall was assessed retrospectively in 2 patients with hemitruncus. A pulmonary atretic valve region was recorded in 10 of 11 of the patients with pseudotruncus. Peripheral contrast echocardiography enabled to distinguish patients with complete obstruction to pulmonary flow from patients with unobstructed right ventricular outflow tract. By showing no direct connection between the pulmonary arteries and the ascending aorta or direct continuity between one or both pulmonary arteries and truncal or aortic root, differentiation of pseudotruncus arteriosus from truncus or hemitruncus may be achieved by 2-D echo.     

Microcinephotography of the developing heart in neural crest-ablated chick embryos

Microcinephotography was used to study heart development in a neural crest model of heart defects, that is, persistent truncus arteriosus, interrupted aortic arch, double outlet right ventricle, or single ventricle and tricuspid valve anomalies. These defects were created in chick embryos by ablation of premigratory neural crest destined for the aorticopulmonary and truncal septa, as well as the third and fourth aortic arch arteries. When embryogenesis reached the looped cardiac tube stage of development (Hamburger-Hamilton stage 18), 19 experimental and 15 control embryos were filmed at 100 frames per second under controlled environmental conditions. Analysis of the microcinephotography films showed the following significant distinguishing characteristics of the developing heart in the experimental embryos: altered conotruncal shape in 100%, depressed contractility and dilation of the primitive ventricle in 84%, decreased emptying of the bulbus cordis in 79%, incompetent truncal cushions in 68%, incomplete looping of the cardiac tube in 58%, and fourth right aortic arch artery without blood flow and third right aortic arch artery with increased flow in 53%. These abnormal characteristics suggested that there were functional and morphological changes in the developing heart of experimental embryos before the time when the predicted structural heart defects would be apparent. It is proposed that the primitive ventricle might attempt to compensate for depressed contractility by ventricular dilation. The incompetent truncal cushions could be secondary to the depressed contractility or secondary to the neural crest ablation that is known to cause persistent truncus arteriosus, an interrupted aortic arch, or both. The absence of blood flow in the right fourth aortic arch artery that will become the definitive aorta correlates with the expected incidence of interrupted aortic arches in this neural crest-ablation model of heart defects. It is speculated that the incomplete looping of the cardiac tube might hinder normal developmental alignment of the outflow and inflow tracts, producing a spectrum of lesions of maldevelopment of the tricuspid valve and dextroposition of the aorta.     

Isolation of the left common carotid or left innominate artery

Isolation of the left common carotid or left innominate artery from the aortic arch is rare. A six week malformed infant with a right aortic arch had isolation of a left innominate artery and connection to the pulmonary artery by a left ductus arteriosus. A right ductus arteriosus had been ligated. Another infant with a right aortic arch and ostium primum atrial septal defect was shown to have an aberrant left subclavian artery arising from the lower descending aorta. The left common carotid artery filled retrogradely and drained into the pulmonary artery by a left ductus arteriosus. This abnormality has not been reported before.     

Isolation of the left common carotid or left innominate artery.

Isolation of the left common carotid or left innominate artery from the aortic arch is rare. A six week malformed infant with a right aortic arch had isolation of a left innominate artery and connection to the pulmonary artery by a left ductus arteriosus. A right ductus arteriosus had been ligated. Another infant with a right aortic arch and ostium primum atrial septal defect was shown to have an aberrant left subclavian artery arising from the lower descending aorta. The left common carotid artery filled retrogradely and drained into the pulmonary artery by a left ductus arteriosus. This abnormality has not been reported before.     

The rare association of truncus arteriosus with a cervical double aortic arch presenting with left main bronchial compression

Truncus arteriosus, a double aortic arch, and a cervical aortic arch are all rare cardiovascular anomalies. We experienced a unique female newborn with the rare combination of truncus arteriosus with a cervical double aortic arch, which probably resulted from abnormal persistence of the bilateral 2nd or 3rd rather than the 4th embryonic aortic arches and failure of regression of the right 8th somitic segment of the right dorsal aorta. She presented with respiratory distress soon after birth, which was initially attributed to the vascular ring and hypertensive pulmonary arteries. Our inability to relieve her respiratory compromise by surgical division of the vascular ring and main pulmonary artery banding prompted the diagnosis of left main bronchial compression caused by a posteriorly displaced dilated ascending aorta that compressed the right pulmonary artery and left main bronchus against the descending aorta. The patient then underwent successful left main bronchus stent implantation. We speculate the cervical double aortic arch is redundant in nature and is a loose ring that may not cause tracheal compression. Nevertheless, a posteriorly displaced dilated ascending aorta in patients with truncus arteriosus may compress the right pulmonary artery and the main bronchus on the side of the aortic arch against the descending aorta.     

Bilateral ductus arteriosus (or remnant): an analysis of 27 patients

Bilateral ductus arteriosus (DA) was clinically recognized in 27 patients studied angiographically from 1963 through May 1983. Distal bilateral DA origin of non-confluent pulmonary arteries was identified in 15 patients, ectopic or distal ductal origin of 1 pulmonary artery in 9 patients (5 without evidence of intracardiac disease) and isolation of the left subclavian artery in 3 (all 3 of whom had a right aortic arch). Other conditions reported to be associated with bilateral DA include interruption of the aortic arch with isolation of a subclavian artery, aortic atresia with interruption of the aortic arch in which bilateral DA supports the entire systemic circulation, bilateral DA complicating forms of congenitally malformed hearts other than those just stated, and, rarely, bilateral DA in isolation. Understanding the symmetric or paired nature of the primitive aortic arch system in the developing human heart facilitates recognition of the patterns of fourth and sixth arch anomalies seen with bilateral DA.     

Interrupted Aortic Arch with Anomalous Origin of Left Pulmonary Artery from Aorta

We report a case of interrupted aortic arch and origin of the left pulmonary artery from the aorta with bilateral ductus arteriosus and discuss its possible embryological basis. To the best of our knowledge, this combination of anomalies has not been reported in the English medical literature.     

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.     

复杂性动脉导管未闭的外科治疗

目的 :介绍复杂性动脉导管未闭 (PDA)诊断和手术治疗。方法 :采用胸骨正中切口。一期治疗PDA和心内伴发畸形。依据导管粗细 ,肺动脉扩张程度 ,采用结扎法和深低温低流量法经肺动脉缝闭PDA。要确认PDA周围的解剖 ,包括主动脉、左、右肺动脉 ,以免误扎。结果 :本组 72例 ,女性占6 7% ;PDA直径 0 3～ 1 8cm。伴发心内畸形中以室间隔缺损为主占 6 0 % ,法洛四联症 18%。死亡 1例 ,系合并室间隔缺损伴主动脉弓离断 ,误扎生命依赖导管。结论 :一期治疗PDA及伴发的心内畸形 ,避免二次手术的损伤 ,为安全、有效的治疗方法。及时发现恰当处理PDA ,决定治疗的结果 ,需特别引起重视。     

Coarctation, tubular hypoplasia, and the ductus arteriosus. Histological study of 35 specimens.

A histological study has been made in an attempt to study further the relation between the ductus arteriosus, coarctation, and tubular hypoplasia of the aortic arch. Thirty-five aortic arch systems were studied using serial sectioning techniques. Twelve were from patients with coarctation and/or tubular hypoplasia. The other 23 hearts were from patients without aortic obstructive lesions, 7 from anatomically normal hearts, and the others from malformed hearts with anomalies elsewhere from the aortic arch. The anatomical study of the hearts with obstructive aortic lesions emphasised the necessity of distinguishing 'coarctation' from 'tubular hypoplasia', since the curtain lesion of coarctation was found to coexist with tubular hypoplasia in some cases. The histological study showed that the ductus was easily distinguished from the walls of the aorta or pulmonary artery. In all these cases with coarctation or tubular hypoplasia a sling of ductal tissue was located around the aortic isthmal orifice. In 6 hearts a diaphragm of ductal tissue was seen to form the coarctation lesion.     

Coarctation, tubular hypoplasia, and the ductus arteriosus. Histological study of 35 specimens.

A histological study has been made in an attempt to study further the relation between the ductus arteriosus, coarctation, and tubular hypoplasia of the aortic arch. Thirty-five aortic arch systems were studied using serial sectioning techniques. Twelve were from patients with coarctation and/or tubular hypoplasia. The other 23 hearts were from patients without aortic obstructive lesions, 7 from anatomically normal hearts, and the others from malformed hearts with anomalies elsewhere from the aortic arch. The anatomical study of the hearts with obstructive aortic lesions emphasised the necessity of distinguishing 'coarctation' from 'tubular hypoplasia', since the curtain lesion of coarctation was found to coexist with tubular hypoplasia in some cases. The histological study showed that the ductus was easily distinguished from the walls of the aorta or pulmonary artery. In all these cases with coarctation or tubular hypoplasia a sling of ductal tissue was located around the aortic isthmal orifice. In 6 hearts a diaphragm of ductal tissue was seen to form the coarctation lesion.     

Truncus arteriosus communis associated with interrupted aortic arch: a report on two uncommon cases.

The paper presents two infants with the A-4 type of truncus arteriosus communis (according to Van Praagh's classification). One patient who survived a surgical procedure demonstrated a rare variant of aortic arch interruption to the left off the left subclavian artery (type A according to Celoria and Patton), whereas the second presented an uncommon anomaly in which the right subclavian artery originated from the descending aorta with associated severe truncal valve incompetency. The authors describe the clinical picture along with the surgical treatment of the first infant who being six days old was subjected to a correction employing the wide patent ductus arteriosus to reconstruct the aortic arch, following the method described by Gomes and McGoon. Subsequently an aortic homograft was implanted in order to connect the right ventricle and the pulmonary artery.     

Growth of the great vessels in the normal human fetus and in the fetus with cardiac defects

BACKGROUND. There is a paucity of quantitative anatomic data regarding human great vessel development that could be useful as a reference for fetal echocardiographers who must distinguish abnormal from normal cardiac development at early stages. METHODS AND RESULTS. To determine normal growth patterns, we plotted the diameters of the aortic and pulmonary valves, ductus arteriosus, aortic isthmus, and descending aorta in 274 autopsy specimens from nonselected spontaneous abortuses of normal karyotype. There was a linear increase in the diameters of these structures within the developmental period studied (10-26 weeks). A relative narrowing of the aorta at the isthmus compared with the aortic valve and descending aorta probably indicates that the majority of fetal left heart output goes to the developing heart and brain. In contrast to previous studies of late gestation and neonatal animals, however, we found that the diameter of the aortic isthmus was larger than that of the ductus arteriosus, suggesting substantial isthmic blood flow in these midtrimester fetuses. Among nineteen other hearts with diverse defects, both of two hearts with a narrow isthmus had an enlarged ductus arteriosus and one heart with pulmonary atresia/intact septum had a narrow ductus and increased aortic valve diameter. CONCLUSIONS. During midgestation, the normal heart may have substantial aortic isthmic blood flow that diminishes due to rerouting in late gestation when increased requirements of the fetal brain and other organs prevail. Although fetal shunts may explain some vessel abnormalities, the majority of cardiac defects in this study were not associated with abnormal growth of the great vessels within this developmental age range.     

Hypoplastic left heart syndrome: is echocardiography accurate enough to guide surgical palliation?

Two-dimensional echocardiography can diagnose hypoplastic left heart syndrome. However, with the advent of the possibility of palliative open heart surgery, complete anatomic diagnosis is necessary. The anatomic findings of 15 neonates with hypoplastic left heart syndrome (age 1 to 10 days, mean 4.1) who had two-dimensional Doppler echocardiographic studies were compared with the results obtained by angiography (6 cases), surgery (11 cases) and autopsy (8 cases). Complete two-dimensional echocardiographic examination of the aortic arch, pulmonary and systemic venous return, atrial septum, ductus arteriosus and proximal coronary arteries was possible in all 15 neonates and correctly diagnosed hypoplastic left heart syndrome in each. Anatomic two-dimensional echocardiographic assessment was accurate in 13 (86%) of the 15 neonates and there were no false positive results. Undiagnosed associated abnormalities were hypoplasia of a left pulmonary artery in one patient and left superior vena cava in another. Accurate quantitation of the size of the tricuspid valve anulus, ascending aorta, pulmonary anulus and right and left pulmonary arteries was possible. Doppler examination was performed in seven patients and confirmed retrograde aortic arch flow and right to left systolic shunting in the patent ductus arteriosus. In selected neonates, surgical palliation can be attempted without angiography.