Inadvertent irreversible closure of arterial duct following therapeutic use of transplacental indomethacin in a fetus with severe Ebstein's anomaly and circular shunt

We report on a fetal case of Ebstein's anomaly with severe tricuspid regurgitation, functional pulmonary atresia and progressive circular shunting (CS) across a widely patent ductus arteriosus (DA) and regurgitant pulmonary valve, contributing to significant systemic hypoperfusion. To mitigate the extent of CS and allow the pregnancy to continue, maternal non-steroidal anti-inflammatory drug (NSAID) therapy with indomethacin was started at 33 + 5 weeks to induce DA constriction. Rather than achieving the desired narrowing of the DA, the treatment led to its complete closure and only minimal antegrade flow across the pulmonary valve. While closure of the DA resulted in the anticipated improvement in fetal hemodynamics, at birth, the child was at risk of severe hypoxemia and its consequences due to the lack of adequate pulmonary perfusion. Reduction and eventual discontinuation of the NSAID treatment did not result in DA reopening. Our experience illustrates the risk of unintended irreversible DA closure when NSAIDs are used to treat CS. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Diagnosis of major heart defects by routine first-trimester ultrasound examination: association with increased nuchal translucency, tricuspid regurgitation and abnormal flow in ductus venosus

OBJECTIVE

To examine the association between fetal major heart defects and increased nuchal translucency thickness (NT), tricuspid regurgitation and abnormal flow in the ductus venosus in a large population of singleton pregnancies undergoing routine ultrasound examination at 11-13 weeks' gestation.

METHODS

This was a retrospective study of prospectively collected data from singleton pregnancies attending for a routine ultrasound scan at 11-13 weeks' gestation, which included examination of fetal anatomy, measurement of NT and assessment of blood flow across the tricuspid valve and in the ductus venosus, according to a standardized protocol. The incidence of fetal NT ≥ 95^th and ≥ 99^th percentiles, tricuspid regurgitation and reversed a-wave in the ductus venosus in fetuses with and those without a major heart defect was determined and the performance of each marker and their combination in the detection of major heart defects was calculated.

RESULTS

The study population of 93 209 pregnancies with no apparent chromosomal abnormality included 211 (0.23%) with a fetal major heart defect and 92 998 morphologically normal neonates. In 113 (53.6%) cases with a major heart defect, the diagnosis was made at the 11-13-week scan, in 82 (38.9%) at the 18-24-week scan, in 10 (4.7%) at the third-trimester scan and in six (2.8%) postnatally. At the 11-13-week scan, we diagnosed all cases of tricuspid or pulmonary atresia and polyvalvular dysplasia, > 90% of cases of hypoplastic left heart syndrome or atrioventricular septal defect, about 60% of complex heart defects and cases of left atrial isomerism (interrupted inferior vena cava with normal intracardiac anatomy), 30-40% of cases of tetralogy of Fallot and arch abnormalities, 25% of tricuspid valve abnormalities and about 15% of cases of transposition of the great arteries, but none of aortic or pulmonary stenosis or common arterial trunk. Fetal NT ≥ 95^th or ≥ 99^th percentile, tricuspid regurgitation or abnormal ductus venosus flow was observed in 77 (36.5%), 45 (21.3%), 61 (28.9%) and 58 (27.5%) fetuses with a major heart defect, respectively, and in 5678 (6.1%), 857 (0.9%), 1136 (1.2%) and 1644 (1.8%) of those without a heart defect. Any one of NT ≥ 95^th percentile, tricuspid regurgitation or abnormal flow in the ductus venosus was found in 117 (55.5%; 95% CI, 48.5-62.3%) fetuses with a heart defect and in 8166 (8.8%; 95% CI, 8.6-9.0%) of those without a heart defect. Any one of NT ≥ 99^th percentile or the other two markers was found in 99 (46.9%; 95% CI, 40.0-53.9%) fetuses with a heart defect and in 3517 (3.8%; 95% CI, 3.7-3.9%) of those without a heart defect.

CONCLUSION

At 11-13 weeks' gestation, measurement of fetal NT and assessment of flow across the tricuspid valve and in the ductus venosus can lead to early diagnosis of major heart defect. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

The effects of caffeine on the preterm sheep ductus arteriosus

Caffeine and other methyl xanthines are widely used in the neonatal period. A recent, randomized, placebo-controlled, multicenter trial found that infants who were randomly assigned to caffeine treatment had less need for pharmacologic and/or surgical closure of a patent ductus arteriosus (PDA). We hypothesized that the decreased need for pharmacologic and surgical closure of the PDA after caffeine treatment might be due to a direct effect of caffeine on ductus contractility. We examined preterm fetal lamb ductus arteriosus (from 24 fetuses, 105 +/- 4 d of gestation, term = 147 d), in vitro to determine the direct effects of caffeine on the isometric tension of the ductus arteriosus. Caffeine (0.003-0.3 mM) had no direct effect on ductus arteriosus tension, nor did it affect the contractile response of the ductus arteriosus to increasing oxygen concentrations. Caffeine's lack of effect was observed in both the presence and absence of indomethacin and NG-nitro-L-arginine methyl ester (L-NAME) (inhibitors of prostaglandin and nitric oxide production). In conclusion, we found no evidence of a direct effect of therapeutic caffeine concentrations on ductus contractility.

Mechanisms regulating the ductus arteriosus

A patent ductus arteriosus (PDA) results in increased pulmonary blood flow and redistribution of flow to other organs. Several co-morbidities (i.e., necrotizing enterocolitis, intracranial hemorrhage, pulmonary edema/hemorrhage, bronchopulmonary dysplasia, and retinopathy) are associated with the presence of a PDA, but whether or not a PDA is responsible for their development is still unclear. In this review, comparative physiology between the full term and preterm newborn and the barriers preventing the necessary cascade of events leading to permanent constriction of the PDA are reviewed.

Molecular determinants of atrial and ventricular septal defects and patent ductus arteriosus

Septation defects and patent ductus arteriosus are the most common human cardiovascular malformations (CVMs). Genetic factors play a major part in the origin of these malformations. Recent molecular analyses have shed light on several mendelian forms. In the autosomal dominant Holt-Oram syndrome, both atrial and ventricular septal defects are inherited in association with limb deformity as a result of mutations in the gene encoding the TBX5 transcription factor. Mutations in the NKX2.5 transcription factor gene cause autosomal dominant familial atrial septal defects in association with progressive atrioventricular block as well as complex congenital heart disease. Common atrial syndromes in autosomal dominant Ellis-van Creveld syndrome arise in the context of axial skeletal and limb malformation as a result of mutations in the EVC gene, whose function is unknown. Patent ductus arteriosus occurs in several syndromic forms of congenital heart disease, including Holt-Oram syndrome. Recent analyses of autosomal dominant Char syndrome, which includes, with variable penetrance, patent ductus arteriosus as well as craniofacial and hand malformations, have shown that the syndrome is caused by mutations in the TFAP2B transcription factor gene. Ongoing analyses are poised to determine the contribution of these genes as well as others yet to be identified to common, sporadic forms of congenital heart disease.

Gene transfer in utero biologically engineers a patent ductus arteriosus in lambs by arresting fibronectin-dependent neointimal formation

Closure of the ductus arteriosus requires prenatal formation of intimal cushions, which occlude the vessel lumen at birth. Survival of newborns with severe congenital heart defects, however, depends on ductal patency. We used a gene transfer approach to create a patent ductus arteriosus by targeting the fibronectin-dependent smooth muscle cell migration required for intimal cushion formation. Fetal lamb ductus arteriosus was transfected in utero with hemagglutinating virus of Japan liposomes containing plasmid encoding 'decoy' RNA to sequester the fibronectin mRNA binding protein. Fibronectin translation was inhibited and intimal cushion formation was prevented. We thus established the essential role of fibronectin-dependent smooth muscle cell migration in intimal cushion formation in the intact animal and the feasibility of incorporating biological engineering in the management of congenital heart disease.

Regulation of ductus arteriosus patency by nitric oxide in fetal lambs: the role of gestation, oxygen tension, and vasa vasorum

We hypothesized that nitric oxide (NO) production by the fetal ductus arteriosus is limited because of low fetal PO2, but that at neonatal PO2, NO might be an important regulator of ductus arteriosus tone. We exposed isolated rings of fetal lamb ductus arteriosus to elevated PO2. L-NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase (NOS), and methylene blue and 6-anilino-5,8-quinolinedione (LY83583), inhibitors of guanylate cyclase, produced constriction of the ductus arteriosus. When ductus arteriosus rings were exposed to low PO2, L-NAME had no effect, and methylene blue and LY83583 had only a small effect on ductus arteriosus tone. Sodium nitroprusside and calcium ionophore A23187 relaxed ductus arteriosus rings more than aortic rings, and relaxed ductus arteriosus rings from immature fetuses more than those from late gestation fetuses. In contrast, ductus arteriosus rings from both early and late gestation were equally sensitive to 8-bromo-cGMP. By both reverse transcriptase-polymerase chain reaction and immunohistochemistry, endothelial cell NOS and inducible calcium-independent NOS, but not nerve cell NOS, were detected in the ductus arteriosus. Inducible NOS was expressed only by endothelial cells lining the ductus arteriosus lumen; in contrast, endothelial cell NOS was expressed by both luminal and vasa vasorum endothelial cells. The role of inducible NOS in the ductus arteriosus is uncertain because the potency of a specific inducible NOS inhibitor in constricting the ductus arteriosus was negligible compared with that of an endothelial cell NOS inhibitor. We speculate that NO may be an important regulator of ductus arteriosus tone at high but not low PO2. The endothelial cell NOS isoform found in vasa vasorum may be an important source of NO because removal of ductus arteriosus luminal endothelium only partially blocks the effects of L-NAME, methylene blue, and LY83583.

Prenatal ultrasonographic assessment of the ductus arteriosus: a review

OBJECTIVE

To review current data pertaining to prenatal ultrasonography of the ductus arteriosus.

DATA SOURCES

We reviewed manuscripts published in the English language regarding prenatal ultrasonography and the fetal ductus arteriosus obtained from a MEDLINE search for 1966 onward. Additional sources were identified through cross-referencing.

METHODS OF STUDY SELECTION

Data regarding morphology, physiology, pathophysiology of fetal disease, and hemodynamic changes after administration of various maternal medications and structural congenital anomalies of the ductus arteriosus were selected.

DATA EXTRACTION AND SYNTHESIS

Knowledge of the function of the ductus arteriosus in both normal and abnormal fetal conditions is enhanced by prenatal ultrasonographic findings. Detailed analyses of ductus arteriosus hemodynamics are indicated in well-defined medical conditions, including maternal medication and established structural or functional fetal cardiac disease.

CONCLUSION

The fetal ductus arteriosus is a vascular structure of major functional importance. Knowledge of physiologic hemodynamic changes of blood flow in this vessel obtained by prenatal ultrasonography in conjunction with increasing gestational age, maternal medication, fetal growth restriction, as well as the detection of structural anomalies, may assist in clinical management of complicated pregnancies.

Persistent common atrioventricular canal of the complete form associated with anomalies of the aortic arch system in WKY/NCrj rat fetuses

Atrioventricular (AV) septal defect with a common AV orifice was found in two near-term rat fetuses, which are descendants of an inbred strain, known to genetically develop tetralogy of Fallot, hypertrophic cardiomyopathy, etc. In one fetus the anterior bridging leaflet was almost entirely committed to the left ventricle but in the other it protruded slightly into the right also, coinciding with type A or type B in humans, respectively. The latter fetus had also a subaortic ventricular septal defect with overriding of the aorta and a double aortic arch. Both fetuses had a narrow pulmonary infundibulum with a muscular band, a dysplastic pulmonary valve, and a markedly hypoplastic ductus arteriosus. Complete AV septal defect and tetralogy of Fallot may be linked genetically, with some common underlying developmental processes.

[Large patent ductus arteriosus and interventricular communication associated with congenital absence of the pulmonary valve]

A case of pulmonary valve agenesis with ventricular septal defect and large patent ductus arteriosus is reported in a neonate. Heart failure occurred at 10 days of life; clinical examination showed continuous murmur. Echocardiography and angiocardiography visualized a major dilatation of the pulmonary artery. At cardiac catheterization there was an important left to right shunt through a large ductus, and pulmonary hypertension. There was also marked pulmonic regurgitation. Because of respiratory distress, ligation of ductus arteriosus was performed at 5 weeks of life. Five years later the patient is still in good condition. Patent ductus arterious is rarely associated with pulmonary valvular agenesis and ventricular septal defect. Our case is not explained by the fetal circulation theory described in this heart malformation.

[Vascular rings]

30 patients with vascular rings operated between 1966 and 1985 are described. Age, sex and symptomatology are studied. Nineteen had a double aortic arch, 9 cases had anomalous subclavian artery, 6 patients had right aortic arch with ductus or ligamentum arteriosum, 1 patient had pulmonary artery sling and 1 patient had right aortic arch and ductus arteriosus and anomalous subclavian artery. Associated congenital malformations were seen in 8 (27%) patients. Basic surgical procedures include a left thoracotomy, identification of the aortic arch anatomy and division of anomalous ring. The aortic arch malformations have a good prognosis with early diagnosis ans surgical treatment.

Intrauterine closure of the ductus arteriosus in association with prune belly syndrome

Findings from the autopsy of a preterm neonate with in utero anatomic closure of the ductus arteriosus in association with prune belly syndrome are presented. Marked bladder distention, a major feature of prune belly syndrome, has secondary mechanical effects on fetal thoracic organs, and the fetus might have been exposed to chronic intrauterine stress. This could have affected the prenatal closure of the ductus arteriosus, although no definitive conclusion can be made.

Role of the vagus nerve and its recurrent laryngeal branch in the development of the human ductus arteriosus

The reason that the normal ductus arteriosus has a muscular media, contrasting with the elastic lamellar structure of the adjacent great arteries, is unknown. We examined the hypothesis that the anatomic relationship of the ductus arteriosus to the vagus and recurrent laryngeal nerves during early development might be of importance in influencing ductal morphology. Normal human embryos from the Carnegie Embryological Collection and embryos and fetuses from the Hopkins Pathology Collection were studied microscopically, by reconstructions made from serial histologic sections, or by gross dissection. At Carnegie stage 16 the recurrent laryngeal nerves pass medially from the vagus nerve to the laryngeal area and are caudal to the bilaterally symmetric sixth aortic arches. By stage 18 the right sixth aortic arch has disappeared and the left sixth aortic arch is in a more caudal position relative to the larynx. The left vagus nerve and its recurrent laryngeal branch form a sling supporting the distal (or ductus arteriosus component) of the left sixth aortic arch. In subsequent development there is greater relative separation of the larynx and ductus arteriosus. The media of the ductus arteriosus beneath the supporting nerves is thinner and has less elastic fiber formation than the elastic lamellar media of the adjacent aortic arches. The study shows that the vagus and recurrent laryngeal nerves are in a position to provide mechanical support to the ductus arteriosus during its development and that the morphology of the media of the supported ductus arteriosus differs from that of the adjacent unsupported aortic arches. It is suggested that this local mechanical support may be the reason that the normal ductus arteriosus differentiates as a muscular artery and is therefore able to obliterate its lumen in postnatal life. Without such support the ductal media could develop the abundant elastic fibers characteristic of the normal unsupported aorta and pulmonary trunk and become an abnormal, persistently patent ductus arteriosus.

Response to experimental coarctation of the aorta and pulmonic stenosis in the fetal lamb

The following conditions were surgically created in fetal lambs at the gestational ages of 80 to 90 days: (1) preductal coarctation, (2) postductal coarctation, (3) pulmonic stenosis, and (4) constriction of the ductus arteriosus. Studies performed at the time of delivery showed the following: Preductal coarctation and postductal coarctation often are associated with a dilated ductus arteriosus that remains patent. Pulmonic stenosis often results in prestenotic and poststenotic dilatation that may include the ductus arteriosus. The fetal ventricles become hypertrophied in response to the increased pressure work imposed by the distal stenoses.

[Embryological aspects of anomalies of the aortic arch (author's transl)]

Various anomalies of the aortic arch have been examined angiographically and discussed in their embryological context. Theoretical concepts are based on Rathke's scheme of the aortic arch system. The importance of developmental aspects for the interpretation of anomalies of the aortic arch in angiography is emphasized.

Management of bilateral ductus arteriosus in complex cyanotic heart disease

Bilateral ductus arteriosus (BDA) usually is associated with complex cyanotic heart disease. Since pulmonary valve atresia often is part of the complex, hypoxia may necessitate emergency cardiac catheterization and surgery for these critically ill newborn infants. Optimum management depends on accurate delineation of the intracardiac and great vessel anatomy. Since the ductus arteriosus has a tendency to close spontaneously, the true anatomy of the fourth to sixth aortic arch connections should be determined on the first catheterization. An over-all plan for future care by the medical-surgical team should have been made at the time of the initial surgical procedure. The case histories of four newborn infants with BDA associated with cyanotic heart diseases are reported. The anatomy and basic embryology of the fourth to sixth arch system is reviewed and recommendations for long-term management are given.

Persistent ductus arteriosus: most probably a primary congenital malformation

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[Deformities of the spine and ribs in embryologically related malformations of the heart with cyanosis]

Three cases of severe costovertebral deformities together with embryologically related cardiac malformations (Fallots Tetralogy and Truncus arteriosus communis) are presented. Two patients died because of their thoracic deformities and limited respiratory function. Relationships to similar bizarre veretebral anomalies are discussed. The cause is probably a teratogenic agent, acting between the fifth to eight embryologic week.

Double inlet right ventricle. Two pathological specimens with comments on embryology

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