Aortic Arch Abnormalities Research Articles

Aortoesophageal fistula in a 13-yr-old girl: complication after nasogastric tube placement in the setting of right-sided aortic arch.

To report a case of aortoesophageal fistula in a 13-yr-old girl with a right aortic arch that occurred after nasogastric intubation after surgery for lumbar kyphosis. Case report. Tertiary care pediatric intensive care unit. One 13-yr-old girl who underwent operative repair of a 45-degree kyphosis at the level of the second to fourth lumbar vertebrae. On the eighth postoperative day after operative kyphosis repair and intraoperative placement of a nasogastric tube, sudden massive hematemesis developed and the patient died. Autopsy revealed esophageal ulceration with erosions. One of these had a fistulous tract connecting to the descending aorta. The aortoesophageal fistula was observed where the descending aorta indented the posterior wall of the esophagus, as the aorta crossed the midline from the right side to the left side of the body. In the setting of right-sided aortic arch and other abnormalities of the aortic arch, nasogastric intubation may result in aortoesophageal fistula, massive hemorrhage, and death. Right-sided aortic arch should be added to the list of conditions for which utmost caution during nasogastric intubation is warranted.

Penetrating Injuries to the Innominate Artery in Association with Abnormal Aortic Arch Anatomy

Penetrating trauma to the innominate artery is uncommon and even more unusual when associated with aberrant or unfamiliar anatomical variants as proximal clamping of a common innominate or carotid trunk may result in occlusion of almost all antegrade flow to the brain. We describe three patients that presented over a 4-year period with penetrating trauma of the proximal innominate associated with an abnormal origin of the left carotid artery and a variant of the aberrant right subclavian anomaly where both carotids originated from a common trunk.

Anéis vasculares na infância: diagnóstico e tratamento

To present the study carried out by the Pediatric Surgery Department of Instituto da Criança at the Medical School of Universidade de São Paulo regarding the diagnosis and treatment of children with aortic arch abnormalities and to define the role of complementary exams for diagnosis. Retrospective study of 22 patients with diagnosis of tracheoesophageal compression treated at Instituto da Criança from 1985 to 2000, analyzing pre- and postoperative clinical data, diagnostic exams and outcome. The most frequent diagnosis was right aberrant innominate artery (10 cases), followed by double aortic arch (7 cases) and right aortic arch (5 cases). Respiratory symptoms (86%) and early manifestation (76% since the neonatal period) were predominant. Nevertheless, most cases (60%) had the definitive diagnosis established only after 1 year of life. The most relevant examination for the diagnosis was the esophagogram. The correction of all the anomalies was carried out through left postero-lateral thoracotomy. There were no surgical complications. The outcome was worse in patients with delayed treatment. All children remained symptomatic for up to 6 months, although they had significant improvement in the postoperative period. The diagnosis of vascular rings should be considered in children with early respiratory symptoms and in the wheezing baby with difficult control. The diagnosis may be established just through the esophagogram. Other image studies add few information and they are unnecessary in most cases. Less severe symptoms may persist for variable periods.

Comparative study of mouse trisomy 16 and bis‐diamine treated fetuses: Discrimination of possible contribution of neural crest cells to malformations

ABSTRACT In order to directly compare the malformation complex induced by genetic and environmental factors, mouse trisomy 16 (Ts 16) fetuses and bis‐diamine treated (BDT) mouse fetuses in which pregnant females were orally dosed with 3.0 mg and 1.0 mg/B.W. (g) bisdiamine eight hours apart on 9 days of pregnancy, were examined. Cystic hygroma with generalized edema appeared in most Ts 16 and in less than 50% of BDT fetuses. Blunt snout or facial cleft with aplasia or hypoplasia of the olfactory bulb was observed in BDT fetuses. The thymus was markedly to moderately hypoplastic in Ts 16, and absent or markedly hypoplastic in BDT fetuses. Parathyroid glands were inclined to be unsettled in relative location to the thyroid in Ts 16 and absent in BDT fetuses. Aortic arch abnormalities were present in approximately half of the cases of Ts 16 and in the majority of cases of BDT fetuses. In the conotruncal region, double outlet right ventricle and persistent truncus arteriosus were dominantly observed in Ts 16 and BDT fetuses, respectively. Atrioventricular septal defect was observed in every Ts 16 and in about 30% of BDT fetuses. These results indicate that not only environmental factors but also genetic factors can experimentally induce DiGeorge‐Iike anomaly in mice. Abnormal development relevant to neural crest cells seems to occur typically in BDT fetuses, and incompletely in Ts 16 fetuses.

Association of chromosome 22q11 deletion with isolated anomalies of aortic arch laterality and branching

OBJECTIVESThe purpose of this study was to determine the frequency of chromosome 22q11 deletions in patients with isolated anomalies of the aortic arch and its branches.BACKGROUNDChromosome 22q11 deletions are often present in patients with certain forms of congenital cardiovascular disease, including tetralogy of Fallot, truncus arteriosus and interruption of the aortic arch. Among patients with these anomalies, chromosome 22q11 deletion is more common in those with abnormal aortic arch laterality or branching.METHODSWe studied 66 patients with isolated anomalies of the aortic arch and no associated intracardiac defects for deletions within chromosome 22q11, using fluorescence in situ hybridization with the cosmid probe N25 (D22S75). Arch anomalies included: double aortic arch (n = 22); right aortic arch with aberrant left subclavian artery (n = 28); right aortic arch with mirror-image branching and a vascular ring formed by a left-sided ductus from the descending aorta (n = 5); right aortic arch with mirror-image branching and no vascular ring (n = 4); and left aortic arch with aberrant right subclavian artery (n = 7). In addition, four patients had a cervical aortic arch, four had aortic coarctation and six had hypoplasia/atresia of the proximal pulmonary arteries.RESULTSChromosome 22q11 deletions were found in 16 patients (24%) across the full spectrum of anomalies studied. Among the morphologic variables analyzed, only hypoplasia/atresia of the proximal pulmonary arteries correlated with the deletion (p = 0.03). Among patients with a double arch, the frequency of chromosome 22q11 deletion was higher in those with an atretic minor arch than it was in those with a patent minor arch (p = 0.02).CONCLUSIONSChromosome 22q11 deletion is associated with isolated anomalies of laterality or branching of the aortic arch in 24% of cases in our series. These findings should alert the clinician to consider deletion screening in patients with isolated anomalies of the aortic arch.

Trauma Centers Bleeding Dollars With Balance Sheets in the Red

In Texas, trauma centers lose, on average, $20 million each year. In California, losses total at least $400 million for the state’s major trauma centers, and the California Medical Association is calling for a $300 million infusion of cash into the state’s trauma system just to maintain the services. “Trauma care in Texas is imperiled,” claims Amir Rubin, chief operations officer at Hermann Hospital in Houston. “Texas’ trauma centers are currently delivering the highest levels of critical services to all Texans around the clock, regardless of HMO plan restrictions, regardless of insurance status. These trauma centers however, cannot sustain losses year after year and remain viable.” In Texas, where motorists rack up the highest number of annual motor vehicle accidents (3901 in 1999), trauma centers often mean the difference between life and death for accident victims, who make up the majority of their patients. However, according to a survey of the state’s Level I and II trauma centers by Mr Rubin, most centers are losing large amounts of money. Trauma in the uninsured population accounts for much of the increase during the past decade, according to Mr Rubin’s study. Twenty-one percent of Texans are without health insurance, he reported, with 31% of the population of Harris County (which includes Houston) and 25% of Dallas County uninsured. During the past year, the volume of trauma increased 5.4%, with concurrent increases in operating losses. At the same time, the federal government cut the funding that goes into state Disproportionate Share Payments. These payments were designed to help defray deficiencies between Medicaid payments and the cost of delivering Medicaid and indigent care (for which there is no reimbursement). Payments to private, nonprofit trauma centers declined 23% and those to public, district facilities dropped 11%. “The survey results reveal not only a bleak financial …

Robert James Graves and the cardiovascular responses to postural changes in heart failure

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Symptomatic Vascular Rings in Adulthood: An Uncommon Mimic of Asthma

Symptomatic thoracic vascular rings presenting in adulthood are thought to be rare. During a 3-year time period, we diagnosed four cases of symptomatic vascular rings, which had been treated unsuccessfully for suspected asthma. Spirometry was characterized by normal forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), and FEV1/FVC, decreased peak expiratory flow (PEF), and truncation of the expiratory flow volume loop. Chest radiographs revealed a right aortic arch in each case with computed tomography (CT) or magnetic resonance imaging (MRI) confirming the diagnosis of a vascular ring. The specific abnormalities consisted of right aortic arch with mirror branching of the main arteries and persistent ligamentum arteriosum; right aortic arch with diverticulum and a fibrous embryonic left arch; right aortic arch with aberrant left subclavian artery arising from a diverticulum of Kommerell; and a right aortic arch with persistent ligamentum arteriosum. Although they are uncommon, vascular rings first presenting in adulthood as a mimic of asthma are not rare. This diagnosis should be considered in adults when abnormal truncation of the flow-volume loop occurs or when radiographic aortic arch abnormalities are found.

Antenatal diagnosis of mixoploidy: a case report

Diploid triploid mosaicism, or mixoploidy is a rare perinatal diagnosis. It is characterized by multiple congenital anomalies including mental and growth retardation, facial and body asymmetry, malformed or low set ears, 3-4 finger syndactyly, and ambiguous genitalia (in males). Areas of hyper- and hypo-pigmentation have also been described. The more severe brain, renal, cardiac and ocular anomalies associated with complete triploidy are not apparent in mixoploid individuals. We present a case of antenatal diagnosis by FISH analysis. The index case was a 26yo G2P1 female referred for ultrasound evaluation at 36 weeks secondary to an abnormal aortic arch. Ultrasound findings included echogenic bowel and significant growth deceleration. A 6-week abdominal growth lag was apparent. A review of the patient's records indicated that growth retardation was evident as early as 26 weeks. An amniocentesis was performed for chromosome analysis and lung maturity. Lung maturity was confirmed. FISH was performed for chromosomes 13, 18 and 21 in addition to routine karyotyping. Out of 179 cells, 36 showed 3 signals for chromosome 18. Out of 104 cells, 19 showed 3 signals each for chromosome 13 and 21. Mixoploidy was confirmed by standard karyotype techniques 1 week later. The mother was delivered within 24 hours of receiving the FISH results. Growth retardation, low set ears and 3-4 finger syndactyly were all present at birth. Cord blood and peripheral blood analysis confirmed the diagnosis of mixoploidy. The findings “disappeared” on peripheral blood by 8 wks. Growth restriction has long been recognized as a feature of chromosome abnormalities. We propose that persistent growth asymmetry be considered part of this sequence as well. Review of the prenatal findings of other affected children may help delinete the prenatal phenotype further. The disappearance of the mosaic cell line in the blood makes the prenatal setting the optimal choice.

Congenital heart disease in mice deficient for the DiGeorge syndrome region.

The heterozygous chromosome deletion within the band 22q11 (del22q11) is an important cause of congenital cardiovascular defects. It is the genetic basis of DiGeorge syndrome and causes the most common deletion syndrome in humans. Because the deleted region is largely conserved in the mouse, we were able to engineer a chromosome deletion (Df1) spanning a segment of the murine region homologous to the human deleted region. Here we describe heterozygously deleted (Df1/+) mice with cardiovascular abnormalities of the same type as those associated with del22q11; we have traced the embryological origin of these abnormalities to defective development of the fourth pharyngeal arch arteries. Genetic complementation of the deletion using a chromosome duplicated for the Df1 DNA segment corrects the heart defects, indicating that they are caused by reduced dosage of genes located within Df1. The Df1/+ mouse model reveals the pathogenic basis of the most clinically severe aspect of DiGeorge syndrome and uncovers a new mechanism leading to aortic arch abnormalities. These mutants represent a mouse model of a human deletion syndrome generated by chromosome engineering.

Interrupted aortic arch: diagnosis with gadolinium-enhanced 3D MRA.

Our goal was to describe the use of gadolinium-enhanced 3D MR angiography (MRA) in the diagnosis of interrupted aortic arch (IAA). A review of our MR data base from a 1 year period yielded three patients (1 day, 8 days, and 16 years old) with IAA. All were referred for evaluation of aortic arch abnormalities, only one of whom had suspected IAA. Patients were imaged at 1.5 T with a 3D spoiled gradient echo pulse sequence (TR/TE 3.8-8/1.3-2.7 ms) following the administration of intravenous gadolinium chelates. Surgical correlation was available in all cases. In the patient with clinically suspected IAA, a previously unsuspected aberrant right subclavian artery was identified that was not seen on preoperative echocardiography. In another patient with a history of previous mediastinal surgery, IAA was diagnosed without concomitant cardiac anomalies, suggesting surgical ligation. In the remaining patient, IAA was detected as well as a patent truncus arteriosus. Gadolinium-enhanced 3D MRA may provide for a rapid diagnosis of IAA that may not be possible with other noninvasive modalities. The rapid acquisition time enables unstable pediatric patients to spend minimal time in the MR suite.

Complete MR angiography and Doppler ultrasound as the sole imaging modalities prior to carotid endarterectomy

To assess the combination of duplex Doppler ultrasound (DUS) and complete carotid magnetic resonance angiography (MRA) for the non-invasive imaging of carotid disease and their effect on outcomes. Determine inter-reader agreement of carotid MRA. One-hundred and ten carotid bifurcations were evaluated using DUS, 2D and 3D time-of-flight MRA from the aortic arch to the Circle of Willis in 55 patients. Percentage stenoses were determined by two blinded readers using standardized criteria. Clinical follow-up was by chart review. Correlation of Doppler and MRA was excellent (r=0.903, P<0.001). Inter-reader agreement (K) for MRA was good: internal carotid artery (ICA) (0.750), external carotid artery (ECA) (0.674) and common carotid artery (CCA) (0.410). Differences in CCA readings were due to minor differences in categorizing lesions as CCA versus ICA or ECA. MRA and Doppler detected nine occluded ICAs. Two DUS occlusions had ICA flow by MRA; one due to a reconstituted precavernous ICA, one a near occluded vessel. Five patients (9%) had surgical management modified by MRA with four not having surgery: three distal ICA/Siphon occlusions and one less severe stenosis by MRA. One tandem lesion not visualized by DUS was surgically significant. Nine aortic arch abnormalities had no surgical impact, possibly due to small sample size. Of 41 endarterectomies, there were no complications from errors of diagnosis. Carotid MRA correlates well with DUS with good inter-reader agreement. MRA confirms Doppler findings, expands anatomical information and identifies tandem lesions from the aortic arch to the Circle of Willis which can affect surgical management. This approach to carotid artery imaging appears to have no negative effect on surgical outcome.

Morphologic features of the normal aortic arch in neonates, infants, and children pertinent to growth

The aorta in newborns rapidly adapts by growth to postnatal circulatory conditions. The question arises what structural features are associated with growth and whether differences occur between the various segments. Nineteen specimens have been studied: seven from babies less than 1 month, seven from 1 month to 1 year, and five from 1 to 4 years. In each baby the diameter of the aortic segments and its branches were measured. Histologically the number of elastin lamellae was counted, and furthermore, collagen density was quantified at several measurement sites. The diameter of each segment increases rapidly after birth and more so than that of the descending aorta, except for the brachiocephalic artery and its branches and the left common carotid artery, albeit not at the same rate. The ascending aorta is the only segment that shows a decrease in the ratio of elastin lamellae to diameter. Collagen density was always highest in the descending aorta. These observations show that postnatal growth of the thoracic aorta is associated with distinct structural remodeling soon after birth; these observations are of clinical relevance in case of aortic arch abnormalities.

The spectrum of extrinsic lower airway compression in children: MR imaging.

V ascular rings, such as aortic arch anomalies and pulmonary sling, cause characteristic patterns of midtracheal compression on plain radiographs [ 1 ]. The MR appearances of these lesions are described in the literature [2]. Recently, in an attempt to contain cost, reports have suggested surgical planning based on findings on plain radiographs and barium studies alone [3]. However, extrinsic airway compression has multiple, not uncommon, causes other than the classically described vascular rings. Mass effect from an abnormal course, enlargement, or malposition of any vascular structure or from a nonvascular mass adjacent to the airway can cause compression. In many cases of extrinsic airway compression, the airway is compressed at the level of the carina or proximal main bronchi. Radiographs are insensitive for detecting compression of the distal airway [4]: in these cases. radiographic findings are often normal. Also, some anatomic variations in aortic arch abnormalities that may affect the surgical approach are not depicted on plain radiographs or barium studies [2]. MR imaging accurately shows the level, severity, and cause of airway compression. Concepts about lower airways compression in children should be redefined to include causes other than the classic causes of midtracheal narrowing. We categorize causes of exainsic airway obstruction other than the classically described causes of midIraCheal narrowing as related to enlarged ascending aorta, malpositioned descending aorta, enlarged pulmonary arteries, enlarged left atrium, nonvascular mediastinal masses, or abnormal thoracic configuration. This pictorial essay illustrates the MR appearance of this spectnim ofcauses ofairway compression.

Abnormal patterning of the aortic arch arteries does not evoke cardiac malformations

Ablation of the cardiac neural crest results in abnormal development of the aortic arch arteries leading to altered patterning of the great arteries. The cardiac outflow tract is also affected after neural crest ablation because normally a subset of neural crest cells migrates from the pharyngeal region to form the outflow septum. Using neural crest ablation, it has not been possible to separate the occurrence of aortic arch maldevelopment from cardiac outflow tract dysmorphogenesis. In order to determine whether normal aortic arch artery development is a prerequisite for normal outflow tract development, we have used a combination of antisense treatment with backtransplantation of cardiac neural folds to produce abnormal patterning of the aortic arch arteries. Paralogous groups of Hox messages with their anterior expression domains in pharyngeal arches 3, 4 and 6 were targeted. Antisense targeted to paralogous group 3 Hox message caused aortic arch 3 located within the pharyngeal arch to regress in a manner similar to aortic arch 2, while antisense targeted to paralogous group 5 Hox message caused the appearance of an additional pharyngeal arch containing a novel and completely independent aortic arch artery. Antisense treatment targeting paralogous group 4 Hox message led to no detectable cardiovascular phenotype in the first 6 days of development. While regression of arch artery 3 was associated with abnormal branching patterns of the aorta and pulmonary trunk, this did not involve abnormal separation of the aorta and pulmonary trunks, the semilunar valves or the subvalvular region of the outflow tract. Because none of these changes in pharyngeal or aortic arch artery development was accompanied by abnormal development of the cardiac outflow tract, it appears that normal patterning of the aortic arch arteries is not a prerequisite for normal heart development. Using reverse transcription polymerase chain reaction (RT-PCR) we were unable to detect changes in any of the Hox messages except group 4, thus, using this particular experimental strategy, we are unable to demonstrate or refute that expression of hox genes by cardiac neural crest cells controls aortic arch patterning. Development of the cardiac outflow tract was normal in each instance. This suggests that abnormal aortic arch patterning does not necessarily lead to cardiac malformations.

Abnormalities in lymphocyte populations in infants with neural crest cardiovascular defects.

The DiGeorge syndrome has been associated with various immune deficits. Embryologically, defects of the neural crest are associated with conotruncal and aortic arch abnormalities. The objective of this study was to determine if children with neural crest congenital heart defects can have subtle but significant immunodeficiencies. Complete blood counts with differential counts and a standard lymphocyte immunophenotyping panel of selected monoclonal antibodies were performed on peripheral blood from 20 children with neural crest cardiac disease and 34 normal newborns. The children with cardiac disease were grouped as survivors and nonsurvivors. The mean total white blood cell count was similar for all groups, but the percent lymphocytes was significantly less in the nonsurvivors than in the survivors and normal newborns (p < 0. 02). The lymphocyte subsets affected were CD2, CD3, and CD4. When the cardiac patients were compared to the normal newborns, again differences in lymphocyte subsets CD2, CD3, and CD4 were seen. When comparing nonsurvivors with survivors, the mean percentages of the CD2, CD3, and CD4 T lymphocyte markers, as well as the mean lymphocyte, B cell (CD20), and natural killer cell (CD16) percentages were all lower in the nonsurvivors. It was concluded that abnormalities in specific lymphocyte populations and their subsets may be predictors of infants at greatest risk for immunodeficiency complications. Therefore children with neural crest cardiac defects should have evaluations of lymphocyte subsets at birth and be treated as if potentially immunodeficient.

Usefulness of banding of the pulmonary trunk with single ventricle physiology at risk for subaortic obstruction

This study addresses the effects of early banding of the pulmonary trunk and subsequent management of sub-aortic obstruction on the attainment of acceptable pre Fontan hemodynamics in patients with a single left ventricle and aorta arising from an outflow chamber. We report our experience with 26 patients seen at our institution between January 1984 and December 1994 with a diagnosis of double-inlet left ventricle or tricuspid atresia and transposed great arteries, who were initially managed with pulmonary artery banding in the first 6 months of life. Pulmonary artery band placement was performed at an age of 2.1 ± 1.8 months (mean ± SD). Associated aortic arch abnormalities were present in 8 patients (31%). There were 19 patients (73%) who underwent treatment with a Damus-Kaye-Stansel procedure or ventricular septal defect (VSD) enlargement for a significant subaortic gradient or morphologically small VSD, alone or in conjunction with a Glenn or Fontan procedure. Eighteen of 26 patients (69%) underwent cardiac catheterization to assess their candidacy for the Fontan operation. Of this group, 16 were classified as low to moderate risk and 2 as high-risk Fontan candidates, based on hemodynamic criteria. The cumulative mortality for the entire cohort was 19%. Our results suggest that this high-risk group of patients can undergo effective pulmonary artery banding as an initial palliative step, with subsequent intervention for subaortic obstruction when it is documented or highly suspected, and that acceptable pre-Fontan hemodynamic parameters can be achieved.

Deep hypothermic circulatory arrest with and without retrograde cerebral perfusion.

Our study indicated that RCP provided significant protection against both postoperative strokes and early death. However, in the subjects studied, the combined detrimental effects of postoperative stroke, COPD, cardiac complications, and procedures requiring composite valve replacement outweighed the protective benefit afforded by RCP in the prevention of early death. RCP's protective benefit was also diminished in the presence of pre-existing cerebrovascular disease. Although the major factors leading to the incidence of postoperative stroke and early mortality were the etiologies and pathologies brought to the operating theater by the patient, RCP when used in conjunction with DHCA significantly diminished the likelihood of either outcome. Therefore, given its simplicity of application in the surgical repair of aortic arch abnormalities, its indication seems warranted.

Anomalous origin of the left main pulmonary artery from the ascending aorta associated with Digeorge syndrome

We place on record 2 infants with the DiGeorge syndrome and anomalous origin of the left pulmonary artery from the ascending aorta. We postulate that: (1) embryogenesis of anomalous origin of the left pulmonary artery from the ascending aorta might be due to the persistent fifth aortic arch connecting both arterial systems; (2) an anomalous pulmonary artery arising from the ascending aorta is part of the aortic arch abnormality accompanied by normal conotruncal septation; and (3) in the DiGeorge syndrome, cardiac anomalies that originate from the conotruncus or aortic arch, or both, may have the same embryologic mechanisms.

1002-90 Deletions in Chromosome 22: A Common Cause of Conotruncal and Aortic Arch Defects

The acronym CATCH 22 (Cardiac defects, Abnormal facies, Thymic hypoplasia, Cleft palate, and Hypocalcemia from deletions in chromosome 22) has been coined to describe the occurrence of microdeletions at the 22q11 locus in 75–90% of patients with DiGeorge and Shprintzen syndromes. Because little data are available regarding the frequency of deletions in non-syndromic patients with congenital heart defects, we screened 61 patients with conotruncal cardiac defects and aortic arch abnormalities. Testing included FISH (fluorescent in situ hybridization) studies with the N25 (D22S75) digoxigenin-labeled DNA probe (Oncor, Gaithersburg, MD) and high resolution cytogenetic analysis. FISH revealed deletions in 8 of 20 patients with tetralogy of Fallot, 5 of 6 with absent pulmonary valve, 4 of 9 with pulmonary atresia/malalignment ventricular septal defect, 3 of 11 with truncus arteriosus, 4 of 8 with interrupted aortic arch, 1 of 2 with anomalous origin of the right pulmonary artery (hemitruncus), and 0 of 5 patients with double outlet right ventricle. Only 7 of the 25 patients with a deletion had a clinical diagnosis of DiGeorge or Shprintzen syndromes. FISH testing in 8 sets of parents demonstrated 3 individuals with deletions. These data show a high (41%) prevalence of CATCH 22 deletions in patients with congenital conotruncal or aortic arch defects. Early detection of patients with deletions facilitates genetic counseling and the identification of medical problems associated with CATCH 22 deletions.