Association of distal displacement of the left subclavian artery and coarctation of the aorta

Summary Previously noted but undocumented observation of distal displacement of the left subclavian artery in patients with discrete coarctation of the aorta was verified by an objective two-dimensional echocardiographic method in 28 patients with aortic coarctation and in 43 control subjects.Relative position of brachiocephalic arteries to one another was evaluated by the ratio of the distance between the left common carotid and the left subclavian artery to the distance between the innominate and the left common carotid artery.Large distance between the left common carotid and the left subclavian artery was reflected by high value of the derived ratio. In neonates with aortic coarctation, the ratio was 1.69, SD±0.66, compared to 1.04, SD±0.40 in the control group. In older children this ratio was less discriminatory.We also observed that the left subclavian artery formed an acute angle (<90°) with the proximal (upstream) segment of the aortic arch in infants with aortic coarctation. In all control infants, this angle was equal to or greater than 90°.A corresponding necropsy study confirmed the echocardiographic findings.We conclude that distal displacement of the left subclavian artery is associated with coarctation of the aorta. It can be accurately visualized and objectively assessed by the two-dimensional echocardiographic technique proposed.     

Magnetic Resonance Imaging of a Distorted Left Subclavian Artery Course: An Important Clue to an Unusual Type of Double Aortic Arch

The objective of this study was to determine if distortion of the left subclavian artery course distinguishes double aortic arch with atretic left dorsal aorta from right aortic arch with mirror image branching. We performed a retrospective case series at a tertiary care center. Twenty-six patients undergoing magnetic resonance imaging for suspicion of a vascular ring were identified, 6 of whom had an atretic left dorsal aorta confirmed by surgical inspection. Six patients with the diagnosis of right aortic arch with mirror image branching were identified for comparison. The course of the left subclavian artery was assessed using surface-rendered magnetic resonance angiography (MRA) and axial fast spin echo images. All patients with double aortic arch had clinical symptoms suggestive of esophageal or tracheal compression. Six patients had double aortic arch, 3 of whom had an atretic left dorsal aorta. In these 3 patients, the branching patterns on MRA mimicked right aortic arch mirror image branching except for the distortion of the initial course of the left subclavian artery. Surgical observation confirmed the presence of an atretic left dorsal aorta that resulted in tension on the left subclavian artery pulling it posteriorly and inferiorly and completing the vascular ring. Patients with right aortic arch mirror image branching demonstrated no such subclavian artery distortion, and these patients did not have clinical symptoms suggestive of a vascular ring. Our results demonstrate that left subclavian artery distortion due to traction by an atretic left arch is an important diagnostic finding in the evaluation 6 patients with suspected vascular rings.     

The subclavian artery as the first branch of the aortic arch

Summary Four patients in whom the subclavian artery arose as the first branch of the ascending aortic arch are presented: two with four separate brachiocephalic arteries and two with a common trunk supporting both carotid arteries.     

Markedly hypoplastic circumflex retroesophageal right aortic arch: MR imaging and surgical implications

Background Circumflex retroesophageal right aortic arch with a markedly hypoplastic retroesophageal segment is a rare anomaly of the aortic arch. Adequate surgical management relies on precise diagnosis, which might not be feasible with echocardiography. Objective To demonstrate the utility of MR imaging in establishing the diagnosis and to describe potential pitfalls in making the diagnosis. Materials and methods Three patients with a circumflex retroesophageal right aortic arch with a markedly hypoplastic retroesophageal segment were retrospectively evaluated. All patients underwent evaluation by echocardiography and MR imaging. The MR imaging consisted of 3-D MR angiography in two patients and fast gradient recalled echo with cardiac-triggered segmented acquisition in one patient. Surgical confirmation was obtained on all three patients. Results The arch anatomy was accurately depicted in all three patients by MR imaging and in none of the patients by echocardiography. Conclusion MR imaging is extremely useful in establishing the diagnosis of markedly hypoplastic retroesophageal circumflex right aortic arch and thus helps in surgical planning.     

Diagnosis of vascular rings and slings using an interleaved 3D double-slab FISP MR angiography technique

Background: Congenital upper airway obstruction and dysphagia may be caused by vascular rings and slings. Often, invasive and radiation-dependent diagnostic procedures are needed to clarify the diagnosis. Objective: To evaluate the diagnostic utility of high-resolution, free-breathing three-dimensional double-slab fast imaging with steady precession magnetic resonance angiography (3D FISP MRA) in infants and children with respiratory upper airway obstruction and/or dysphagia for detection or exclusion of vascular rings and slings. Materials and methods: Eleven patients (median age 1.3 years; range 5.1 months to 15.8 years) were investigated prospectively with 3D FISP MRA and spin-echo techniques. Additional diagnostic data were available from surgery (n=7), cardiac catheterization (n=5), CT (n=2), barium swallow (n=3) and bronchoscopy/oesophagoscopy (n=4). Results: In one case, diagnosis was missed with low-resolution spin-echo sequences, but high-resolution 3D FISP MRA revealed a double aortic arch. 3D FISP MRA accurately found (n=8) or excluded (n=3) vascular rings or slings in all patients. Using a five-level grading system for 3D FISP MRA image quality (1=non-diagnostic; 5=excellent), the mean grade was 4.3±0.7 with no significant grade difference between two independent observers (P=0.81). Conclusions: High-resolution 3D FISP MRA accurately defined or excluded vascular rings and slings in patients with respiratory symptoms and/or dysphagia. This technique may provide a non-invasive, radiation-free alternative without contrast agents for diagnosis of vascular rings and slings in free-breathing infants and children.Electronic supplementary material is available for this article at     

Evaluation of aortic regurgitation in congenital heart disease: value of MR imaging in comparison to echocardiography

Background Evaluation of the severity and the follow-up of aortic insufficiency (AI) are important tasks in paediatric cardiology. Assessment is based on clinical and echocardiographic (ECHO) findings such as the configuration of the valve and the regurgitation fraction (RF). Objective The goal of this study was to evaluate MRI compared to ECHO for determination of clinical severity, valve morphology and RF. Materials and methods Thirty patients (age 3–27 years) with mild-to-severe AI were evaluated by clinical examination, ECHO (2-D and Doppler), and MRI at 1.5 T (2-D true-FISP cine short axis, phase-contrast flow in the ascending aorta). Results Both methods identified 13 bicuspid and 17 tricuspid valves. Good correlations between ECHO and cine MRI were found for ventricular mass, stroke volume, and ejection fraction. A good linear correlation was found for the RF determined by ECHO and phase-contrast MRI (r = 0.7). The RF was 6% in mild AI, 17% in moderate AI, and 30% in severe AI. The different severity groups showed significantly different RF and it was possible to discriminate between clinical severity grades (P = 0.01). Conclusion ECHO and MRI showed good agreement in evaluating morphology and function of the left ventricle. The clinical severity of the disease can be evaluated correctly using MRI. Sebastian Ley and Joachim Eichhorn contributed equally.     

The frequency, significance, and management of a right aortic arch in association with esophageal atresia

An unrecognised right aortic arch (RAA) found at thoracotomy may complicate the repair of oesophageal atresia (OA) and tracheo-oesophageal fistula (TOF). This paper analyses the patient characteristics, peri-operative management, and outcome of 16 infants with a RAA, and proposes management guidelines. Between 1948 and 1996, 709 patients with OA/TOF were admitted to the Royal Children's Hospital, of whom 13 had a RAA. Three additional cases from two other paediatric surgical units were included. All 16 case records were reviewed retrospectively. The overall incidence of RAA in OA was 1.8%. Neither a chest radiograph in 16, nor antenatal ultrasonography in 7 detected a RAA. Post-natal echocardiography (ECHG) detected a RAA in only 1 of 7 infants examined; that patient underwent repair of the OA through a left (L) thoracotomy. The other 15 infants underwent initial right (R) thoracotomy. Six of these had a complete repair from the R side and 5 had division of the fistula only; 2 of these 5 had initial division of the fistula, and the OA was repaired through a repeat R thoracotomy 4 and 7 weeks later. In the remaining 4 infants where the fistula could not be located at the initial R thoracotomy, complete repair proved possible through the L chest. Three of these infants underwent an immediate L thoracotomy; the 4th had a delayed L thoracotomy 1 week later. There were 6 deaths: these occurred early in the study and were related to severe prematurity, congenital heart disease (CHD), and post-operative respiratory complications. CHD was identified in 11 of 16 infants (71%). Routine pre-operative ECHG is unreliable in determining the laterality of the aortic arch. Should a RAA be encountered during a R thoracotomy for OA, it is often possible to divide the fistula and repair the OA from that side, but where repair looks potentially difficult it is wise to proceed to an immediate L thoracotomy.     

MR imaging of isolated left ventricular apical hypoplasia

We report the MRI findings in a 3-month-old boy with isolated left ventricular apical hypoplasia. This is a recently described congenital abnormality that consists of an odd, spherically shaped left ventricle due to absence of the ventricular apex. To our knowledge, isolated left ventricular apical hypoplasia has not been reported in a child. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

An isolated left subclavian artery supplied by a collateral artery from the abdominal aorta

An isolated left subclavian artery is a rare anomaly. We report a 9-month-old boy with an isolated left subclavian artery associated with tetralogy of Fallot and the right aortic arch. MRI and angiography show that the blood supply through the left subclavian artery was maintained by a large tortuous collateral artery from the abdominal aorta. This type of collateral artery structure is unique.     

MDCT angiography of isolated right subclavian artery

Isolation of a subclavian artery is an uncommon congenital anomaly of the aortic arch in which one subclavian artery loses its connection with the aorta and originates from the homolateral pulmonary artery by way of a ductus arteriosus. Isolation of the left subclavian artery in patients with a right aortic arch is well known. However, isolated right subclavian artery with a left-sided aortic arch is an extremely rare condition. In this report, we present multidetector computed tomographic (MDCT) angiography findings of an isolated right subclavian artery associated with a common carotid trunk and an anomalous origin and proximal interruption of the left pulmonary artery.     

Aberrant right subclavian artery with left aortic arch: Associated cardiac anomalies

Summary Anomalous origin of the right subclavian artery (ARSA) from the aorta distal to the normally positioned left subclavian artery is a relatively frequent congenital anomaly in subjects with left aortic arch. The purpose of this study was to determine the relative frequency of associated cardiovascular anomalies in individuals with this anomaly. From the records of approximately 11,000 pathologic specimens in the Registry of Cardiovascular Disease of United Hospital (St. Paul, MN, USA), we found 128 (1.2%) with ARSA.Of the 128 ARSA, 117 (2.9%) occurred among 4102 instances of congenital heart disease.The 117 cases with congenital heart disease and ARSA were conotruncal anomalies in 38%, septal defects in 28%, obstructive anomalies of the left side of the heart in 21%, right heart anomalies in 5%, and miscellaneous conditions in the other 8%. Down syndrome existed in 14 (12%) of the 117 specimens with ARSA and some congenital cardiac anomaly; nine of the latter had an atrioventricular canal (AVC) malformation.     

A persistent fifth aortic arch in man: A double-lumen aortic arch (presentation of a new case and review of the literature)

Summary Persistent fifth aortic arch manifested as a double-lumen aortic arch (DLAA) is a rare anomaly. We present such a case with transposition of the great arteries, ventricular septal defect (VSD), and pulmonary atresia. Review of the eight previously published cases indicates relatively frequent association of DLAA with preductal coarctation of the aorta. We attempt to explain the coexistence of this lesion with DLAA. We also discuss evidence supporting derivation of the inferior channel of the DLAA from the embryologic fifth aortic arch.     

Magnetic resonance angiography of an ipsilateral double aortic arch due to persistent left fourth and fifth aortic arches

Persistence of a fifth aortic arch with an ipsilateral fourth arch manifested as a double-lumen aortic arch (DLAA) is a rare congenital anomaly. We present one of the first cases diagnosed by magnetic resonance angiography (MRA) in a 7-year-old girl referred for treatment of subaortic membrane and aortic regurgitation.     

Comparative imaging of differential pulmonary blood flow in patients with congenital heart disease: magnetic resonance imaging versus lung perfusion scintigraphy

Background: Lung perfusion scintigraphy is considered the gold standard to assess differential pulmonary blood flow while magnetic resonance (MR) has been shown to be an accurate alternative in some studies. Objective: The purpose of the study was to assess the accuracy of phase contrast magnetic resonance (PC-MR) in measuring pulmonary blood flow ratio compared with lung perfusion scintigraphy in patients with complex pulmonary artery anatomy or pulmonary hypertension and to document reasons for discrepant results. Materials and methods: We identified 25 cases of congenital heart disease between January 2000 and 2003, in whom both techniques of assessing pulmonary blood flow were performed within a 6-month period without an interim surgical or transcatheter intervention. The study group included cases with branch pulmonary artery stenosis, intracardiac shunts, single ventricle circulation, pulmonary venous anomalies and conotruncal defects. The mean age at study was 5.7 years (range 0.33–12) with a mean weight of 20.3 kg (range 6.5–53.6). The two methods were compared using a Bland-Altman analysis, and the Pearson correlation coefficient was calculated using the lung scan as the gold standard. Discrepant results were examined by reviewing the source images to elucidate reasons for error by MR. Results: Bland-Altman analysis comparing right pulmonary artery (RPA) blood flow percentage, as measured by each modality, showed a mean difference of 1.43±9.8 (95% limits of agreement: –17.8, 20.6) with a correlation coefficient of r=0.84, P<0.0001. In six (24%) cases a large difference (>10%) was found with a mean difference between techniques of 17.9%. The reasons for discrepant results included MR artifacts, dephasing owing to turbulent flow, site of data acquisition and lobar lung collapse. Conclusion: When using PC-MR to assess pulmonary blood flow ratio, important technical errors occur in a significant proportion of patients who have abnormal pulmonary artery anatomy or pulmonary hypertension. If these technical errors are avoided, PC-MR is able to supply both anatomic and quantitative functional information in this patient population.     

MRI diagnosis of isolated origin of the left subclavian artery from the left pulmonary artery

Right aortic arch with isolation of the left subclavian artery is a rare disorder. In this entity, the left subclavian artery has its origin from the pulmonary artery via the ductus arteriosus. We report an infant with an unbalanced atrioventricular septal defect, right aortic arch, bilateral ductus arteriosi and an isolated left subclavian artery. This infant also had chromosome 22q11 deletion. The origin and course of the isolated subclavian artery were well-demonstrated using contrast-enhanced 3-D magnetic resonance angiography. This non-invasive diagnostic modality can accurately reveal detailed mediastinal vascular anatomy in a young infant and allows diagnosis of aberrant vascular connections.     

Right circumflex retro-oesophageal aortic arch with coarctation of a high-positioned right arch

We present a rare case of right circumflex retro-oesophageal aortic arch with coarctation of a high-positioned right arch. A 7-month-old boy presented with a cardiac murmur. Cardiac situs was normal and there was no evidence of an intracardiac shunt or patent ductus arteriosus. MR aortography revealed a right aortic arch that was high-positioned, tortuous and narrowed. This right aortic arch crossed the midline behind the oesophagus and continued as a left-sided descending aorta. The left common carotid and subclavian arteries arose from a large branching vascular structure that derived from the top of the left-sided descending aorta. The right common carotid artery arose from the ascending aorta. The proximal portion of the right common carotid artery showed very severe stenosis and poststenotic dilatation. The right subclavian artery originated distal to the narrowed and tortuous segment of the aortic arch.     

Multicenter Experience with Perventricular Device Closure of Muscular Ventricular Septal Defects

Hybrid procedures are becoming increasingly important, especially in the management of congenital heart lesions for which there are no ideal surgical or interventional options. This report describes a multicenter experience with perventricular muscular venticular septal defect (VSD) device closure. Three groups of patients (n = 12) were identified: infants with isolated muscular VSDs (n = 2), neonates with aortic coarctation and muscular VSDs (n = 3) or patients with muscular VSDs and other complex cardiac lesions (n = 2), and patients with muscular VSDs and pulmonary artery bands (n = 5). Via a sternotomy or a subxyphoid approach, the right ventricle (RV) free wall was punctured under transesophageal echocardiography guidance. A guidewire was introduced across the largest defect. A short delivery sheath was positioned in the left ventricle cavity. An Amplatzer muscular VSD occluding device was deployed across the VSD. Cardiopulmonary bypass was needed only for repair of concomitant lesions, such as double-outlet right ventricle, aortic coarctation, or pulmonary artery band removal. No complications were encountered using this technique. Discharge echocardiograms showed either mild or no significant shunting across the ventricular septum. At a median follow-up of 12 months, all patients were asymptomatic and 2 patients had mild residual ventricular level shunts. Perventricular closure of muscular VSDs is safe and effective for a variety of patients with muscular VSDs.     

Prenatal MR imaging of a meconium pseudocyst extending to the right subphrenic space with right lung compression

Meconium pseudocyst results from a loculated inflammation occurring in response to spillage of meconium into the peritoneal cavity after a bowel perforation. Certain cystic lesions, such as abscesses and dermoid and epidermoid cysts, are known to show reduced water diffusion on DWI. MRI has recently become a valuable adjunct to ultrasonography for fetal gastrointestinal anomalies. Complementary to ultrasonography, prenatal MRI can help further characterize the lesion and can clearly demonstrate the anatomical relationship between the lesion and adjacent organs. We report a case of meconium pseudocyst that was prenatally imaged with ultrasonography and MRI, postnatally complicated by pneumoperitoneum, and proved by postnatal surgery and histopathology. We emphasize the MRI of the pseudocyst, particularly T1-weighted and diffusion-weighted imaging.     

MR imaging appearance of laryngeal atresia (congenital high airway obstruction syndrome): unique course in a fetus

Congenital high airway obstruction syndrome (CHAOS) is a rare life-threatening syndrome. Most cases are diagnosed prenatally by US. We report a fetus with this syndrome that showed a unique course revealed on MRI. Ultrasonography at 22 weeks demonstrated that the fetus had ascites and bilaterally enlarged hyperechoic lungs. Congenital infection, congenital cystic adenomatoid malformation or CHAOS was suspected. Subsequent MRI performed at 24 weeks demonstrated bilaterally enlarged high-signal lungs, dilated bronchi, massive ascites, subcutaneous oedema and polyhydramnios. MRI confirmed the diagnosis of CHAOS. A second MRI at 35 weeks showed that the bilateral lung enlargement, ascites, oedema and polyhydramnios had resolved, but that the appearance of the airway was unchanged. The infant was delivered by caesarean section at 38 weeks of gestation and immediate tracheostomy was performed. This spontaneous regression was explained by a tracheo-oesophageal fistula that may have decreased the intrathoracic pressure.