Second-trimester fetal aberrant right subclavian artery: original study, systematic review and meta-analysis of performance in detection of Down syndrome

OBJECTIVES

First, to estimate the prevalence of fetal aberrant right subclavian artery (ARSA) in our population and its association with Down syndrome. Second, to determine the feasibility of ultrasound to visualize ARSA in the three planes. Finally, to carry out a systematic review of the literature on the performance of second-trimester ARSA to identify fetuses with Down syndrome.

METHODS

ARSA was assessed by ultrasound in the axial plane and confirmed in the longitudinal and coronal planes during the second half of pregnancy in women attending our unit (from February 2011 to December 2012). A search of diagnostic tests for the assessment of ARSA was carried out in international databases. Relevant studies were subjected to a critical reading, and meta-analysis was performed with Meta-DiSc.

RESULTS

Of the 8781 fetuses in our population (mean gestational age: 24 ± 5.4 weeks), 22 had Down syndrome. ARSA was detected in the axial view in 60 cases (0.7%) and confirmed in the coronal view in 96.7% and in the longitudinal view in 6.7% (P < 0.001). Seven cases with ARSA had Down syndrome and all were in the non-isolated-ARSA group. The estimates of positive likelihood ratio (LR) were 0 for isolated ARSA and 199 (95% CI, 88.9-445.2) for non-isolated ARSA. In the systematic review, six studies were selected for quantitative synthesis. The pooled estimates of positive and negative LRs for global ARSA were, respectively, 35.3 (95% CI, 24.4-51.1) and 0.75 (95% CI, 0.64-0.87). For isolated ARSA, the positive and negative LRs were 0 (95% CI, 0.0-14.7) and 0.98 (95% CI, 0.94-1.02), respectively.

CONCLUSIONS

The prevalence of ARSA seems close to 1%. The coronal plane is the most suitable for its confirmation after detection in the axial plane. Detection of isolated or non-isolated ARSA should guide decisions about karyotyping given that isolated ARSA shows a weak association with Down syndrome.

Different Proinflammatory Cytokine Serum Pattern in Neonate Patients Undergoing Open Heart Surgery. Relevance of IL-8

The purpose of this work was to investigate the clinical significance of serum levels of proinflammatory cytokines in pediatric patients undergoing cardiopulmonary bypass. We divided the patients in two groups: 8 neonates, and 19 non-newborn children. IL-1beta, IL-6, IL-8, and TNF serum levels were quantified before sternotomy, at admission to the PICU (30 min postoperatively), 24 h after the onset of surgery and 3 days after the operation. Surgical cardiac stress elicits significant increments of IL-6, IL-8 and TNF serum concentrations in both neonates and non-neonates, regardless of their preoperative clinical condition. However, in newborns the magnitude of the proinflammatory cytokine increments was, in particular with IL-8, remarkably greater than in older children. Moreover, neonate and non-neonate patients showed clearly disparate patterns of serum concentrations over time of both IL-8 and TNF. There was a marked relationship between IL-8 levels and postoperative morbidity, evaluated by pulmonary dysfunction, days on inotropic support and days of PICU stay in both neonates and non-neonates patients. In contrast, we found no relationship between serum levels of IL-6 and TNF and postoperative clinical data. Newborn and non-newborn patients undergoing cardiopulmonary bypass exhibit dissimilar patterns of proinflammatory cytokines. IL-8 might be implicated in the multiorganic dysfunction related to cardiopulmonary bypass in pediatric patients.

Analysis of the human neonatal thymus: evidence for a transient thymic involution

The neonatal period is marked by the impairment of the major components of both innate and adaptive immunity. We report a severe depletion of cortical CD4+CD8+ double-positive thymocytes in the human neonatal thymus. This drastic reduction in immature double-positive cells, largely provoked by an increased rate of cell death, could be observed as early as 1 day after birth, delaying the recovery of the normal proportion of this thymocyte subset until the end of the first month of postnatal life. Serum cortisol levels were not increased in newborn donors, indicating that the neonatal thymic involution is a physiological rather than a stress-associated pathological event occurring in the perinatal period. Newborn thymuses also showed increased proportions of both primitive CD34+CD1- precursor cells and mature TCRalphabetahighCD69-CD1-CD45RO+/RAdull and CD45ROdull/RA+ cells, which presumably correspond to recirculating T lymphocytes into the thymus. A notable reinforcement of the subcapsular epithelial cell layer as well as an increase in the intralobular extracellular matrix network accompanied modifications in the thymocyte population. Additionally neonatal thymic dendritic cells were found to be more effective than dendritic cells isolated from children's thymuses at stimulating proliferative responses in allogeneic T cells. All these findings can account for several alterations affecting the peripheral pool of T lymphocytes in the perinatal period.

[Hemodynamic changes during laparoscopic surgery. Preliminary study]

The haemodynamic changes produced by laparoscopic surgery in children have been evaluated. A transesophageal echocardiographic study on 13 patients (7 males and 6 females, 10.8 +/- 2.7 years old) has been performed before, during and after peritoneal CO2 gas insufflation. A change on the Doppler waves pattern of the infradiaphragmatic veins along with an increase in blood flow velocity were observed. Pulmonary veins suffered minimal changes showing an increase on either the systolic pressure and on atrial contraction. Diastolic retrograde flow in aorta reflected an increase in peripheral vascular resistance. Cardiac output increased minimally. All haemodynamic changes returned to basal after gas peritoneal desufflation. These data show that laparoscopic surgery could produce important cardiac derangements in children with ventricular dysfunction or in patients presenting left ventricular outlet obstruction. In these patients laparoscopic surgery might be precluded.

[Wallenberg syndrome in childhood secondary to the striking by lightening]

Wallenberg's Syndrome (WS) is exceptional in childhood. We present a case of a 10 year-old girl with a WS caused by an embolism in the right lateral portion of the medulla secondary to an electrofulguration, but with an unusual progressive outcome, developing clinical signs of medial medullar injury, leading even into a respiratory failure 30 days after admittance. She only became stable after surgical lesion decompression. There was no evidence of vascular malformation, finding only a great oedema. The pathology only showed changes compatible with brain infarction. This case makes again clear the superiority of MRI upon CT-scan to diagnose a WS. We think that the unusual progression of the lesion was due to great medullar oedema found on surgery, involving the brain regional flow.

Cardiac two-dimensional imaging and reference values for blood flow velocities in the ovine fetus

Since the ovine model is the most commonly used for foetal haemodynamic investigation it was felt important 1) to investigate the technical difficulties involved with ultrasound fetal cardiac imaging in this species and 2) to establish normal reference values for ovine cardiac and umbilical blood flow velocity measurements. Both two-dimensional and pulsed Doppler techniques were used for this assessment in 25 unsedated ewes. All morphological features described in human features to identify the ventricular cavities could be found in the ovine fetus with the two-dimensional echocardiogram. Specific differences included a flatten thorax as visualized from the lateral position, the mesocardial position of the heart, and a large left azygos vein behind the left atrium draining blood into a dilated coronary sinus. The mean peak velocities (cm/sec) of the early diastolic wave (E) and the atrial wave (A), along with their calculated ratio, were not statistically different between the two atrio-ventricular valves (E: 30.6 +/- 6.6, 31.2 +/- 6.1; A: 43.0 +/- 8.3, 41.6 +/- 8.0; E/A: .72, .76 for mitral and tricuspid valves respectively). A significant difference was observed between the acceleration times of the blood ejected into the aorta and the pulmonary artery, with the time interval being shorter in the pulmonary artery (Aorta: 0.052 +/- 0.011; Pulmonary artery: 0.037 +/- 0.009 s). A mean pulsatility index of the umbilical artery of 0.89 was recorded. The data recorded in this study should serve as a reference base for further non-invasive studies of the ovine foetal circulatory system using the ultrasound technique.

Closure of the ductus arteriosus: determinant factor in the appearance of transient peripheral pulmonary stenosis of the neonate

We speculated that a relationship may exist between transient peripheral pulmonary stenosis and the closure of the ductus arteriosus. Fifty preterm infants had pulmonary artery and ductal color Doppler flow velocity assessments performed before and after closure of the ductus arteriosus. No flow turbulence or increase in velocity was observed immediately after birth, although a significant discrepancy in size was observed between the main pulmonary artery and its two branches. After closure of the ductus, 15 infants had signs of transient peripheral pulmonary stenosis of the left pulmonary artery in association with a significant decrease of diameter at the origin of the same artery. In all 50 infants, no significant gradient was observed in the right pulmonary artery. We conclude that, at least in the preterm infant, transient peripheral pulmonary stenosis is not present at birth but is an acquired phenomenon closely related to closure of the ductus arteriosus.

[Congenital cardiac diverticulum originating from both ventricles]

Congenital cardiac diverticuli are infrequent. More so, if one is specially restrictive with the criteria. Usually, they are not isolated but a part of a malformation syndrome that affects the medium thoraco-abdominal line and have an embryological explanation. We present a case of congenital cardiac diverticulum originating from both ventricles with a thoraco-abdominal malformation. We describe the clinical findings, the nuclear magnetic resonance, the echocardiography and cardiac catheterization. We comment the anatomy, the total diagnosis, therapy and complications.

[Pulmonary valvuloplasty in children with cyanotic cardiopathy]

We present 5 patients with cyanotic congenital heart disease in whom a pulmonary valvuloplasty was performed as palliative therapy. The patients symptoms were hypoxemic spells, very low oxygen saturation and no weight gain. The oxygenation improved and symptoms disappeared. We believe that in properly selected patients this technique represents a good therapeutic modality.

Diastolic circulatory dynamics in the presence of elevated placental resistance and retrograde diastolic flow in the umbilical artery: a Doppler echographic study in lambs

To evaluate the effects of elevated placental resistance on the diastolic blood flow in the main arteries of the fetus, placental resistance was mechanically increased in six exteriorized lambs. A string was inserted into the exposed section of the umbilical cord and placed around the veins isolating them from the arteries. Doppler flow velocities waveforms were measured by placing a lightweight acoustic bag on the umbilical cord. Placental resistance was increased by tightening the string until retrograde diastolic flow was observed in the umbilical artery. All measurements were obtained within 10 minutes. Heart rate, PO2, PCO2, and pH before umbilical vein compression were 177 +/- 24 beats/min, 16.4 +/- 1.8 mm Hg, 42.5 +/- 4 mm Hg, and 7.3 +/- 0.05, respectively, and 112 +/- 38 beats/min, 5.9 +/- 1.5 mm Hg, 56.6 +/- 7.0 mm Hg, and 7.2 +/- 0.05, respectively, after umbilical vein compression. The patterns of diastolic flow observed after compression were descending aorta, retrograde; aortic arch, retrograde; ascending aorta, bidirectional; cephalic aorta, forward, which were quite different from their respective baseline patterns. It is concluded that the appearance of reverse diastolic flow in the umbilical artery indicates that (1) the lowest vascular resistance in the fetal circulatory network is no longer at the placental but at the cerebral level, and (2) preplacental blood with low oxygen content from the descending aorta and pulmonary artery is being shifted toward the brain.

Effect of intermittent positive pressure ventilation on diastolic ventricular filling patterns in premature infants

Eleven preterm newborn infants had a Doppler echocardiographic examination of their ventricular filling patterns during intermittent positive pressure ventilation. Peak velocity during early ventricular filling (VE) and during atrial systole (VA) and diastolic velocity-time integral of early (IE) and late (IA) ventricular filling caused by atrial contraction were measured. The ratios of VE/VA and IE/IA were also calculated. Diastolic peak velocities, as well as the diastolic velocity-time integral of early and late ventricular filling measured through the mitral valve were significantly higher during inspiration. The peak of the wave representing the velocity during atrial systole (A) was always higher than the peak of the wave representing the velocity of early ventricular filling (E). As a result, the ratio of these two variables (E/A) was always less than 1, showing no significant variation from inspiration to expiration. The flow patterns into the right ventricle were the opposite of those observed through the mitral valve. During inspiration, a significant decrease (p less than 0.001) in peak and time integral velocities of both the early ventricular filling and atrial systole waves was observed. Heart rate did not vary with respiration. It is concluded that during positive pressure ventilation, inspiration decreases right ventricular filling and enhances left ventricular filling. Opposite changes are recorded during expiration. Early and late phases of diastolic filling are equally affected. These changes are different from those observed during spontaneous breathing and should be taken into account in the assessment of diastolic ventricular function in preterm infants requiring assisted ventilation.

Dilated and contracted forms of primary endocardial fibroelastosis: a single fetal disease with two stages of development

Left ventricular endocardial fibroelastosis was diagnosed by echocardiographic scanning in a fetus at 20 weeks' gestation. Repeated prenatal examination over the next 20 weeks' gestation showed the development of the left ventricle from a chamber with a dilated cavity to a small cavity with a very thick wall. These findings were confirmed at necropsy and by the absence of other morphological anomalies. The contracted form of primary fibroelastosis in the fetus must have followed an insult that prevented any further increase in the size of the left ventricular cavity.

[Neonatal lupus erythematosus: complete atrioventricular block and SSA/Ro antibodies]

A newborn boy with complete A-V block and positive anti-SSA/Ro antibodies is reported. Authors comment on pathological findings of neonatal lupus erythematosus. They also review prognosis and clinical course and point out management of these patients before and after birth.

Mitral valve prolapse secondary to right ventricular enlargement in patients with pulmonary hypertension after toxic rapeseed oil ingestion

A high incidence of mitral valve prolapse (MVP) has been reported in various entities which produce important right ventricular (RV) enlargement with normal or decreased left ventricular (LV) volume. To evaluate the importance of RV enlargement in the genesis of MVP in these cases, we analyzed the echocardiographic studies from 176 patients with 'Síndrome Tóxico'. These patients underwent M-mode, cross-sectional and pulsed Doppler examination because of the suspicion of having dietary pulmonary hypertension, a complication which occurred in almost 20% of patients with this epidemic poisoning and which showed a course of gradual resolution in most of them. RV size was classified according to the RV/LV maximal short-axis dimension ratio as normal, border-line, moderately enlarged and severely enlarged. MPV was diagnosed according to standard M-mode and cross-sectional echocardiographic criteria. A second echocardiographic examination was obtained in 38 patients 12.5 +/- 5.3 months after the first one. The incidence of MVP was 9.3% in patients with normal RV size (N = 107), 9.5% in patients with border-line RV size (N = 23), 30% in patients with moderate RV enlargement (N = 30) and 56% in patients with severe RV enlargement (N = 16) (P less than 0.001). Fourteen (77%) of the 18 patients with MVP and moderate or severe RV enlargement (N = 16) (P less than 0.001). Fourteen (77%) of the 18 patients with MVP and moderate or severe RV enlargement had holosystolic MVP. At pulsed Doppler examination, no patient showed signs of mitral regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of age on wall thickness, cavity dimensions and myocardial contractility of the left ventricle in simple transposition of the great arteries

This study was carried out to establish a reference table of echocardiographic values for the left ventricle of simple d-transposition of the great arteries (d-TGA) and to determine at what age left ventricular dimensions in these patients become different from those of a normal population. Fifty-three patients with d-TGA and normal pulmonary pressure and 395 normal children ages 1 day to 10 years were studied by M-mode echocardiography. Results show that in d-TGA, left ventricular systolic and diastolic internal diameters are normal at birth. After 1 month, however, both diameters were below normal and despite a progressive increase with age, the mean values were always below normal. The mean posterior wall thickness of patients with d-TGA was also normal at birth but did not increase with age (2.3 mm in diastole and 4.3 mm in systole) and became significantly thinner than normal at 10 months of age in diastole and 7 months in systole. Septal thickness of patients with d-TGA did not differ from that of the control group. The shortening fraction and mean velocity of circumferential fiber shortening were significantly greater in d-TGA at all ages. Left ventricular measurements related to age are presented and should be of help in interpreting M-mode echocardiograms of patients with d-TGA.

An epidemic of pulmonary hypertension after toxic rapeseed oil ingestion in Spain

The cardiac profile of 38 patients readmitted to the hospital with the clinical and radiologic findings of pulmonary artery hypertension and right ventricular failure 2 months after ingestion of toxic rapeseed oil was determined with M-mode and two-dimensional echocardiography, pulsed Doppler flow studies and right and left heart catheterization and ventriculography. The echocardiogram and pulsed Doppler recordings revealed right ventricular enlargement in 84% of the patients, indirect evidence of pulmonary artery hypertension in 76% and tricuspid insufficiency in 13%. At cardiac catheterization (n = 11) the mean (+/- standard deviation) pulmonary artery pressure was 40 +/- 9 mm Hg, mean pulmonary systemic vascular resistance ratio was 0.45 +/- 0.12 and mean right ventricular end-diastolic pressure was 13 +/- 4 mm Hg. Pulmonary artery hypertension was sustained after the acute administration of 100% oxygen and persisted in six patients who were restudied within 6 months. Cardiac index and left heart pressures were normal in all but one patient. The contrast ventriculographic studies revealed right ventricular dilation in all patients, tricuspid regurgitation in three patients and a normal left ventricular contraction pattern in all but one patient. The data confirm that symptomatic pulmonary artery hypertension and associated right ventricular dysfunction can complicate toxic rapeseed oil ingestion and that these findings persist for at least 6 months.