The ductus arteriosus: physiology, regulation, and functional and congenital anomalies

Histomorphometric Study of the Tunics of Ductus Arteriosus in Human Fetal Cadavers Using the ImageJ Software

INTRODUCTION

The ductus arteriosus (DA) connects the left pulmonary artery with the aorta during fetal life. Although it connects two elastic arteries, histological studies have shown that it is a muscular artery. There are very few studies on the histomorphometry of human fetal cadaveric DA. There are few studies on the changes in the tunics of the DA at various stages of fetal development. The present study aimed to observe the histomorphometric features of DA and its histological variations according to the gestational age of the fetus.

METHODS

The study sample was DA dissected from 34 fetal cadavers of different gestational ages and stained with standard hematoxylin and eosin staining (H&E). We studied the structure of DA under a light microscope. We used ImageJ software (National Institutes of Health, Bethesda, Maryland) to measure the thickness of all three layers of the DA wall.

RESULTS

The thickness of the DA wall was directly proportional to the gestational age of the fetus. In each trimester, we observed distinct histological changes in the tunics.

CONCLUSION

The formation of multiple intimal mounds and the increase in intimal thickness observed during the last trimester are responsible for the closure of the ductus after birth. Elastosis is associated with patent DA. The disappearance of elastosis at a later gestational age ensures the closure of the ductus.

Prenatal Diagnosis of Ductus Arteriosus Anomalies: A Single-Center Study

To evaluate the fetal ductus arteriosus anomalies diagnosed by fetal echocardiography. The perinatal outcomes and associated cardiac and genetic anomalies are also explored. The fetal echocardiography records of 2366 fetuses were evaluated retrospectively. Thirty-seven pregnancies prenatally diagnosed with ductus arteriosus anomalies and evaluated after delivery were enrolled in the study. Perinatal and obstetric outcomes were analyzed. The incidence of ductus arteriosus anomaly in our series was 1.5% (37/2366). The most frequent ductus arteriosus anomaly detected was right-sided ductus arteriosus followed by aneurysm, constriction and bilateral ductus arteriosus with an incidence of 51.3%, 27.1%, 18.9% and 2.7%, respectively. There were 19 fetuses with right-sided ductus arteriosus, of which 15 had tetralogy of Fallot. There were 2 chromosomal anomalies (22q11 microdeletion) in this group. Of the 7 fetuses with ductus arteriosus constriction, 3 (3/7, 42.9%) died in-utero. There were 2 (2/10, 20%) neonatal deaths due to hypoplastic left heart syndrome in the ductus arteriosus aneurysm group. Various types of ductus arteriosus anomalies can be diagnosed prenatally. Perinatal outcomes mostly dependent on the type of the ductus arteriosus anomaly and accompanying cardiac malformations.

Transcatheter Patent Ductus Arteriosus Closure in Children With Different Devices and Long-Term Results

INTRODUCTION

With the development of transcatheter interventional techniques and the introduction of next-generation duct occluder devices, transcatheter closure has become the first treatment option for patent ductus arteriosus (PDA) in pediatric patients. In this study, we compared the effectiveness and safety of different devices for transcatheter PDA closure in pediatric patients, focusing on long-term outcomes.

METHODS

A total of 235 patients aged 0-18 years who underwent transcatheter PDA closure at a tertiary care center between January 2005 and February 2020 were included. The medical records of the cases were retrospectively evaluated.

RESULTS

The median age of the patients was 2.3 years (range: 3.5 months to 17 years), with a mean weight of 12.8 kg (range: 5.7-43.2 kg). The mean PDA diameter at its narrowest point was 2.9 mm (range: 2.2-5.1 mm). Ductal anatomy was as follows: Type A in 98 (41.7%) patients, Type E in 36 (15.6%) patients, Type C in 32 (13.5%) patients, Type F in 27 (11.4%) patients, Type D in 23 (9.7%) patients, and Type B in 19 (8.1%) patients. Arterial access was used in 138 (57.1%) patients, venous + arterial access in 58 (24.6%) patients, and venous access only in 39 (16.5%) patients. Closure was performed with Amplatzer Duct Occluder (ADO; AGA Medical Corp., Golden Valley, MN, USA) II in 151 (64.2%) cases, ADO I in 43 (18.2%) cases, and coils in 41 (17.4%) cases. The mean fluoroscopy time and mean procedural time were 10.3 ± 4.2 minutes and 41 ± 7.2 minutes, respectively. The mean radiation dose was 1364 ± 497 cGy/min. The early closure rate after the procedure was 92%, while residual shunting on the first day post-procedure was observed in 1.8% of cases, decreasing to 0.1% at the one-month follow-up. The overall procedural success rate for all cases was 96.0%. The mean follow-up duration was 9.7 years (range: 2.9-13.8 years).

CONCLUSION

For percutaneous PDA closure, ADO I devices are preferred for larger defects, whereas ADO II devices are prioritized for small- to medium-sized defects instead of coils.

Echocardiographic parameters predicting spontaneous closure of ductus arteriosus in preterm infants

Objective

To evaluate the value of echocardiographic parameters in predicting early spontaneous closure of ductus arteriosus in premature infants.

Methods

222 premature infants admitted to the neonatal ward of our hospital were selected, and patent ductus arteriosus was detected by echocardiography 48 h after birth. On the 7th day, whether the ductus arteriosus was closed naturally in this cohort was observed. The infants whose ductus arteriosus were not closed were identified as the PDA group (n = 109), and the other infants were included in the control group (n = 113). The echocardiographic parameters of the two groups of premature infants at 48 h after birth were single-factor statistically and Pearson correlation analyzed, and the parameters with statistically significant differences in single-factor analyzed were selected for multivariate logistic stepwise regression analysis.

Results

The ductus arteriosus shunt velocity and the pressure difference between the descending aorta and the pulmonary artery (ΔPs) in the PDA group were lower than those in the control group (P < 0.05). The pulmonary artery pressure (PASP) in the PDA group was higher than that in the control group (P < 0.05). According to the multivariate logistic stepwise regression analysis, only the maximum shunt velocity of ductus arteriosus was correlated with early spontaneous closure of ductus arteriosus in 48 h first echocardiographic parameters (P = 0.049). The receiver operating characteristic (ROC) curve indicates the optimal critical point of echocardiographic ductus arteriosus shunt velocity in premature infants 48 h after birth was 1.165 m/s.

Conclusion

Echocardiographic parameters are of great value in predicting the early spontaneous closure of ductus arteriosus in premature infants. In particular, the ductus arteriosus shunt velocity is correlated with the early spontaneous closure of ductus arteriosus.

Interventions for patent ductus arteriosus (PDA) in preterm infants: an overview of Cochrane Systematic Reviews

BACKGROUND

Patent ductus arteriosus (PDA) is associated with significant morbidity and mortality in preterm infants. Several non-pharmacological, pharmacological, and surgical approaches have been explored to prevent or treat a PDA.

OBJECTIVES

To summarise Cochrane Neonatal evidence on interventions (pharmacological or surgical) for the prevention of PDA and related complications, and interventions for the management of asymptomatic and symptomatic PDA in preterm infants.

METHODS

We searched the Cochrane Database of Systematic Reviews on 20 October 2022 for ongoing and published Cochrane Reviews on the prevention and treatment of PDA in preterm (< 37 weeks' gestation) or low birthweight (< 2500 g) infants. We included all published Cochrane Reviews assessing the following categories of interventions: pharmacological therapy using prostaglandin inhibitor drugs (indomethacin, ibuprofen, and acetaminophen), adjunctive pharmacological interventions, invasive PDA closure procedures, and non-pharmacological interventions. Two overview authors independently checked the eligibility of the reviews retrieved by the search, and extracted data from the included reviews using a predefined data extraction form. Any disagreements were resolved by discussion with a third overview author. Two overview authors independently assessed the methodological quality of the included reviews using the AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews) tool. We reported the GRADE certainty of evidence as assessed by the respective review authors using summary of findings tables.

MAIN RESULTS

We included 16 Cochrane Reviews, corresponding to 138 randomised clinical trials (RCT) and 11,856 preterm infants, on the prevention and treatment of PDA in preterm infants. One of the 16 reviews had no included studies, and therefore, did not contribute to the results. Six reviews reported on prophylactic interventions for the prevention of PDA and included pharmacological prophylaxis with prostaglandin inhibitor drugs, prophylactic surgical PDA ligation, and non-pharmacologic interventions (chest shielding during phototherapy and restriction of fluid intake); one review reported on the use of indomethacin for the management of asymptomatic PDA; nine reviews reported on interventions for the management of symptomatic PDA, and included pharmacotherapy with prostaglandin inhibitor drugs in various routes and dosages, surgical PDA ligation, and adjunct therapies (use of furosemide and dopamine in conjunction with indomethacin). The quality of reviews varied. Two reviews were assessed to be high quality, seven reviews were of moderate quality, five of low quality, while two reviews were deemed to be of critically low quality. For prevention of PDA, prophylactic indomethacin reduces severe intraventricular haemorrhage (IVH; relative risk (RR) 0.66, 95% confidence interval (CI) 0.53 to 0.82; 14 RCTs, 2588 infants), and the need for invasive PDA closure (RR 0.51, 95% CI 0.37 to 0.71; 8 RCTs, 1791 infants), but it does not appear to affect the composite outcome of death or moderate/severe neurodevelopmental disability (RR 1.02, 95% CI 0.90 to 1.15; 3 RCTs, 1491 infants). Prophylactic ibuprofen probably marginally reduces severe IVH (RR 0.67, 95% CI 0.45 to 1.00; 7 RCTs, 925 infants; moderate-certainty evidence), and the need for invasive PDA closure (RR 0.46, 95% CI 0.22 to 0.96; 7 RCTs, 925 infants; moderate-certainty evidence). The evidence is very uncertain on the effect of prophylactic acetaminophen on severe IVH (RR 1.09, 95% CI 0.07 to 16.39; 1 RCT, 48 infants). Necrotising enterocolitis (NEC) was lower with both prophylactic surgical ligation (RR 0.25, 95% CI 0.08 to 0.83; 1 RCT, 84 infants), and fluid restriction (RR 0.43, 95% CI 0.21 to 0.87; 4 RCTs, 526 infants). For treatment of asymptomatic PDA, indomethacin appears to reduce the development of symptomatic PDA post-treatment (RR 0.36, 95% CI 0.19 to 0.68; 3 RCTs, 97 infants; quality of source review: critically low). For treatment of symptomatic PDA, all available prostaglandin inhibitor drugs appear to be more effective in closing a PDA than placebo or no treatment (indomethacin: RR 0.30, 95% CI 0.23 to 0.38; 10 RCTs, 654 infants; high-certainty evidence; ibuprofen: RR 0.62, 95% CI 0.44 to 0.86; 2 RCTs, 206 infants; moderate-certainty evidence; early administration of acetaminophen: RR 0.35, 95% CI 0.23 to 0.53; 2 RCTs, 127 infants; low-certainty evidence). Oral ibuprofen appears to be more effective in PDA closure than intravenous (IV) ibuprofen (RR 0.38, 95% CI 0.26 to 0.56; 5 RCTs, 406 infants; moderate-certainty evidence). High-dose ibuprofen appears to be more effective in PDA closure than standard-dose ibuprofen (RR 0.37, 95% CI 0.22 to 0.61; 3 RCTs, 190 infants; moderate-certainty evidence). With respect to adverse outcomes, compared to indomethacin administration, NEC appears to be lower with ibuprofen (any route; RR 0.68, 95% CI 0.49 to 0.94; 18 RCTs, 1292 infants; moderate-certainty evidence), oral ibuprofen (RR 0.41, 95% CI 0.23 to 0.73; 7 RCTs, 249 infants; low-certainty evidence), and with acetaminophen (RR 0.42, 95% CI 0.19 to 0.96; 4 RCTs, 384 infants; low-certainty evidence). However, NEC appears to be increased with a prolonged course of indomethacin versus a shorter course (RR 1.87, 95% CI 1.07 to 3.27; 4 RCTs, 310 infants).

AUTHORS' CONCLUSIONS

This overview summarised the evidence from 16 Cochrane Reviews of RCTs regarding the effects of interventions for the prevention and treatment of PDA in preterm infants. Prophylactic indomethacin reduces severe IVH, but does not appear to affect the composite outcome of death or moderate/severe neurodevelopmental disability. Prophylactic ibuprofen probably marginally reduces severe IVH (moderate-certainty evidence), while the evidence is very uncertain on the effect of prophylactic acetaminophen on severe IVH. All available prostaglandin inhibitor drugs appear to be effective in symptomatic PDA closure compared to no treatment (high-certainty evidence for indomethacin; moderate-certainty evidence for ibuprofen; low-certainty evidence for early administration of acetaminophen). Oral ibuprofen appears to be more effective in PDA closure than IV ibuprofen (moderate-certainty evidence). High dose ibuprofen appears to be more effective in PDA closure than standard-dose ibuprofen (moderate-certainty evidence). There are currently two ongoing reviews, one on fluid restriction for symptomatic PDA, and the other on invasive management of PDA in preterm infants.

The biventricular contribution to chronic pulmonary hypertension of the extremely premature infant

OBJECTIVE

Evaluate factors associated with significant pulmonary hypertension [PH] (≥2/3 systemic) and its impact on ventricular function at 36 weeks postmenstrual age (PMA).

STUDY DESIGN

Retrospective cohort of infants born at <29 weeks who survived to their echocardiography screening for PH at 36 weeks PMA. Masked experts extracted conventional and speckle-tracking echocardiography [STE] data.

RESULTS

Of 387 infants, 222 were included and 24 (11%) categorized as significant PH. Significant PH was associated with a decrease in tricuspid annular plane systolic excursion (0.79 vs 0.87 cm, p = 0.03), right peak longitudinal strain [pLS] by STE (-19.6 vs -23.1%, p = 0.003) and left pLS (-25.0 vs -22.7%, p = 0.02). The association between biventricular altered function by STE and significant PH persisted after adjustment for potential confounders - LV-pLS (p = 0.007) and RV-pLS (p = 0.01).

CONCLUSION

Our findings are suggestive that premature newborns with significant PH at 36 weeks PMA have a biventricular cardiac involvement to their pathophysiology.

[Fetal and pediatric cardiovascular physiology : Things you should know as an (pediatric) anesthesiologist]

Immediately after birth the physiology of the cardiovascular system of the neonate undergoes some significant changes. The first breaths in life and the inflation of the lungs lead to a considerable drop in pulmonary arterial resistance. This results in the closure of the foramen ovale and ductus arteriosus; however, during the first weeks of life a sharp rise in pulmonary vascular resistance caused by hypoxia, hypercapnia and excessive positive pressure ventilation can lead to the reopening of the ductus arteriosus. This may result in subsequent strain of the left heart. In order to anticipate the reopening of the ductus arteriosus, it is recommended to measure the saturation of peripheral oxygen not only preductal (right hand), but also postductal (feet).An excessive volume therapy should be avoided as the neonatal myocardium is hallmarked by low cardiac compliance, reduced contractility and reduced ventricular filling.Until now there is still no uniform definition of hypotension in pediatric patients. Blood pressure values that are measured in awake children or are derived from the 50% age percentile values can thus only be used as approximate values. In all cases it is mandatory to recognize and consistently treat hypotension during pediatric anesthesia in order to prevent postoperative organ damage, particularly of the brain.The transcranial measurement of cerebral regional oxygen saturation (c‑rSO₂) by means of near-infrared spectroscopy (NIRS) provides valuable information about regional tissue oxygenation of the brain. This enables conclusions about the state of the multifactorial cerebral perfusion to be drawn. In this way monitoring of the hypoxia sensitive cerebral tissue can be accomplished and should be used in premature infants and neonates. When measuring a baseline in awake patients, a 20% drop of c‑rSO₂ from this baseline should be challenged and treated if necessary.

Gestational purple grape juice consumption does not change fetal ductus arteriosus constriction in Wistar rats

Grape juice consumption may influence the early occurrence of ductal constriction during pregnancy, since the consumption of foods rich in polyphenols can be linked to the premature constriction of the ductus arteriosus. This study aimed to evaluate the effect of purple grape juice consumption during gestation on fetal ductus arteriosus closure, prostaglandin levels, and oxidative stress markers in Wistar rats. We divided 18 pregnant rats into four groups: a control group (C), a single-dose grape juice group (SDGJ), a two-dose grape juice group (TDGJ) of 7 μl/g body weight per day, and an indomethacin group (I). Blood was collected on gestational day (GD) 0, 14, and 20. Prostaglandin levels were measured, and the livers and hearts were removed from the mothers and fetuses for oxidative stress analysis; histology of the fetal ductus arteriosus was performed. Prostaglandin levels (pg/ml) at GD 20 were (C:1462.10 ± 314.61); (SDGJ:987.66 ± 86.25); (TDGJ:1290.00 ± 221.57), and (I:584.75 ± 46.77). Fetal ductus arteriosus closure occurred only in the indomethacin group. Lipid peroxidation evaluated through thiobarbituric acid reactive substances (nmol/mg protein) in maternal livers was lower in the grape juice groups (C: 4.11 ± 0.76 nmol/mg protein), (SDGJ: 2.34 ± 0.36), (TDGJ: 1.52 ± 0.18), and (I: 4.20 ± 0.76). Sulfhydryls (nmol/mg protein) were lower in the TDGJ group (C:763.59 ± 61.38 nmol/mg protein), (SDGJ:978.88 ± 158.81), (TDGJ:385.32 ± 86.78), and (I:727.72 ± 49.12). Also, superoxide dismutase activity (USOD/mg protein) was higher in fetal hearts in this group: (C:5.29 ± 0.33), (SDGJ:4.48 ± 0.47), (TDGJ:7.35 ± 0.43), and (I:6.00 ± 0.18). We conclude that grape juice consumption in pregnancy does not induce ductus arteriosus closure in the fetus and presented potential antioxidant effects.

Prophylactic cyclo-oxygenase inhibitor drugs for the prevention of morbidity and mortality in preterm infants: a network meta-analysis

BACKGROUND

Patent ductus arteriosus (PDA) is associated with significant morbidity and mortality in preterm infants. Cyclooxygenase inhibitors (COX-I) may prevent PDA-related complications. Controversy exists on which COX-I drug is the most effective and has the best safety profile in preterm infants.

OBJECTIVES

To compare the effectiveness and safety of prophylactic COX-I drugs and 'no COXI prophylaxis' in preterm infants using a Bayesian network meta-analysis (NMA).

SEARCH METHODS

Searches of Cochrane CENTRAL via Wiley, OVID MEDLINE and Embase via Elsevier were conducted on 9 December 2021. We conducted independent searches of clinical trial registries and conference abstracts; and scanned the reference lists of included trials and related systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that enrolled preterm or low birth weight infants within the first 72 hours of birth without a prior clinical or echocardiographic diagnosis of PDA and compared prophylactic administration of indomethacin or ibuprofen or acetaminophen versus each other, placebo or no treatment.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane Neonatal. We used the GRADE NMA approach to assess the certainty of evidence derived from the NMA for the following outcomes: severe intraventricular haemorrhage (IVH), mortality, surgical or interventional PDA closure, necrotizing enterocolitis (NEC), gastrointestinal perforation, chronic lung disease (CLD) and cerebral palsy (CP).

MAIN RESULTS

We included 28 RCTs (3999 preterm infants). Nineteen RCTs (n = 2877) compared prophylactic indomethacin versus placebo/no treatment, 7 RCTs (n = 914) compared prophylactic ibuprofen versus placebo/no treatment and 2 RCTs (n = 208) compared prophylactic acetaminophen versus placebo/no treatment. Nine RCTs were judged to have high risk of bias in one or more domains.We identified two ongoing trials on prophylactic acetaminophen. Bayesian random-effects NMA demonstrated that prophylactic indomethacin probably led to a small reduction in severe IVH (network RR 0.66, 95% Credible Intervals [CrI] 0.49 to 0.87; absolute risk difference [ARD] 43 fewer [95% CrI, 65 fewer to 16 fewer] per 1000; median rank 2, 95% CrI 1-3; moderate-certainty), a moderate reduction in mortality (network RR 0.85, 95% CrI 0.64 to 1.1; ARD 24 fewer [95% CrI, 58 fewer to 16 more] per 1000; median rank 2, 95% CrI 1-4; moderate-certainty) and surgical PDA closure (network RR 0.40, 95% CrI 0.14 to 0.66; ARD 52 fewer [95% CrI, 75 fewer to 30 fewer] per 1000; median rank 2, 95% CrI 1-2; moderate-certainty) compared to placebo. Prophylactic indomethacin resulted in trivial difference in NEC (network RR 0.76, 95% CrI 0.35 to 1.2; ARD 16 fewer [95% CrI, 42 fewer to 13 more] per 1000; median rank 2, 95% CrI 1-3; high-certainty), gastrointestinal perforation (network RR 0.92, 95% CrI 0.11 to 3.9; ARD 4 fewer [95% CrI, 42 fewer to 137 more] per 1000; median rank 1, 95% CrI 1-3; moderate-certainty) or CP (network RR 0.97, 95% CrI 0.44 to 2.1; ARD 3 fewer [95% CrI, 62 fewer to 121 more] per 1000; median rank 2, 95% CrI 1-3; low-certainty) and may result in a small increase in CLD (network RR 1.10, 95% CrI 0.93 to 1.3; ARD 36 more [95% CrI, 25 fewer to 108 more] per 1000; median rank 3, 95% CrI 1-3; low-certainty). Prophylactic ibuprofen probably led to a small reduction in severe IVH (network RR 0.69, 95% CrI 0.41 to 1.14; ARD 39 fewer [95% CrI, 75 fewer to 18 more] per 1000; median rank 2, 95% CrI 1-4; moderate-certainty) and moderate reduction in surgical PDA closure (network RR 0.24, 95% CrI 0.06 to 0.64; ARD 66 fewer [95% CrI, from 82 fewer to 31 fewer] per 1000; median rank 1, 95% CrI 1-2; moderate-certainty) compared to placebo. Prophylactic ibuprofen may result in moderate reduction in mortality (network RR 0.83, 95% CrI 0.57 to 1.2; ARD 27 fewer [95% CrI, from 69 fewer to 32 more] per 1000; median rank 2, 95% CrI 1-4; low-certainty) and leads to trivial difference in NEC (network RR 0.73, 95% CrI 0.31 to 1.4; ARD 18 fewer [95% CrI, from 45 fewer to 26 more] per 1000; median rank 1, 95% CrI 1-3; high-certainty), or CLD (network RR 1.00, 95% CrI 0.83 to 1.3; ARD 0 fewer [95% CrI, from 61 fewer to 108 more] per 1000; median rank 2, 95% CrI 1-3; low-certainty). The evidence is very uncertain on effect of ibuprofen on gastrointestinal perforation (network RR 2.6, 95% CrI 0.42 to 20.0; ARD 76 more [95% CrI, from 27 fewer to 897 more] per 1000; median rank 3, 95% CrI 1-3; very low-certainty). The evidence is very uncertain on the effect of prophylactic acetaminophen on severe IVH (network RR 1.17, 95% CrI 0.04 to 55.2; ARD 22 more [95% CrI, from 122 fewer to 1000 more] per 1000; median rank 4, 95% CrI 1-4; very low-certainty), mortality (network RR 0.49, 95% CrI 0.16 to 1.4; ARD 82 fewer [95% CrI, from 135 fewer to 64 more] per 1000; median rank 1, 95% CrI 1-4; very low-certainty), or CP (network RR 0.36, 95% CrI 0.01 to 6.3; ARD 70 fewer [95% CrI, from 109 fewer to 583 more] per 1000; median rank 1, 95% CrI 1-3; very low-certainty). In summary, based on ranking statistics, both indomethacin and ibuprofen were equally effective (median ranks 2 respectively) in reducing severe IVH and mortality. Ibuprofen (median rank 1) was more effective than indomethacin in reducing surgical PDA ligation (median rank 2). However, no statistically-significant differences were observed between the COX-I drugs for any of the relevant outcomes.

AUTHORS' CONCLUSIONS

Prophylactic indomethacin probably results in a small reduction in severe IVH and moderate reduction in mortality and surgical PDA closure (moderate-certainty), may result in a small increase in CLD (low-certainty) and results in trivial differences in NEC (high-certainty), gastrointestinal perforation (moderate-certainty) and cerebral palsy (low-certainty). Prophylactic ibuprofen probably results in a small reduction in severe IVH and moderate reduction in surgical PDA closure (moderate-certainty), may result in a moderate reduction in mortality (low-certainty) and trivial differences in CLD (low-certainty) and NEC (high-certainty). The evidence is very uncertain about the effect of acetaminophen on any of the clinically-relevant outcomes.

Safety and efficacy of percutaneous patent ductus arteriosus closure: a multicenter Egyptian experience

Background

Transcatheter closure of patent ductus arteriosus (PDA) has gained acceptance over the last two decades, replacing the surgery in more than 90% of the cases, so the safety and efficacy of transcather closure of PDA have been evaluated by studying different experiences from different centers in developing countries. The aim is to report our experience with PDA transcather closure, with focus on the adverse events and complications faced during the procedure.

Results

Outcome data on PDA transcatheter closure were collected from two different tertiary centers in a multicenter registry. During the period from June 2017 till January 2021, 308 PDA closure were recorded, using device in 197 (64%) and coils in 111 (36%) patients, most of the patients were in pediatric age group from 6 months to 6 years and only 10 patients (3.2%) were adults. Most patients had isolated PDA of 92%, and 9 (2.9%) patients had residual PDAs either post-surgical or transcatheter closure. Median minimum PDA diameter was 2.8 mm (range 1–7.6 mm; IQR 1.8–3.8 mm). The procedure was successful in 293 patients (95%). Complications occurred in 15/308 patients (5%), and only 6 (2%) of them were major complications, but none was life threating. Frequent complications were device embolization (2%), hemolysis (1%), arrhythmia (1%). Younger age, low body weight and longer procedure time were associated with a high complication rate (p < 0.005). Device-related complications were more common than coil-related complications (2.5% versus 0.5%).

Conclusions

Although transcatheter closure of PDA is considered to be effective procedure with low complications rate, however, complications should be anticipated and managed properly.

The Patent Ductus Arteriosus in Adults with Special Focus on Role of CT

The primary imaging modality for the diagnosis of patent ductus arteriosus (PDA) is echocardiography. However, CT may be the technique on which an incidental PDA is first recognized because of the increasing number of chest CT scans performed for a variety of causes. Identification of PDA on CT may lead to earlier closure using a PDA occluder device. Immediate identification of incidental PDA is important, but a high rate of missed diagnosis of PDA has been reported due to its small size and anatomic location. In addition, echocardiography may overlook the presence of even a large PDA due to decrease in the amount of shunting through the PDA caused by high pulmonary artery pressures. This review provides the basic CT anatomy and clinical perspective of PDA, and discusses the role of CT in the evaluation of PDA as well as methods to avoid overlooking a small PDA on CT.

Patent ductus arteriosus: From pharmacology to surgery

Patent ductus arteriosus (PDA) may be found in 0.1-0.2% of term infants, but the average incidence is at least five-fold higher in premature infants, correlating inversely with birth weight and gestational age. While not all patients with a PDA require treatment, the deleterious effects of persistent left-to-right shunting across the ductus can have important short- and long-term consequences. Medical and interventional approaches to PDA closure have evolved greatly in the past decade and add to the decision-making pathways. This article summarizes the pathophysiology of PDA and characterizes the medical, surgical and endovascular treatment approaches.

Transcatheter patent arterial duct closure in premature infants: A new technique to ease access to the patent arterial duct, with particular benefit for the tricuspid valve

BACKGROUND

Transcatheter patent arterial duct (PAD) closure in premature infants has been shown to be feasible. Since our early transcatheter PAD closure procedures in premature infants at Hôpital Necker Enfants Malades, we have changed our technique several times to advance the guidewire through the right heart to avoid tricuspid valve damage.

AIM

To describe the technique we have been using since May 2019, to report our results with a particular focus on tricuspid leaks and to analyse the potential mechanisms of tricuspid lesion development with previous methods.

METHODS

All premature infants weighing<2kg who underwent transcatheter PAD closure with this new technique were included. Demographic data, procedural data, outcome and procedural complications were reviewed, with particular attention to the occurrence of tricuspid regurgitation.

RESULTS

Between May 2019 and May 2020, 33 patients were included. Median gestational age was 25 weeks. Median birth weight and procedural weight were 690g (range 490-1065g; interquartile range [IQR] 620-785g) and 1160g (range 900-1900g; IQR 1030-1300g), respectively. Median age at procedure was 35 (IQR 30-46) days. PAD anatomy was evaluated on transthoracic echocardiography only. The median duct diameter was 3 (IQR 2.5-3.2) mm at the pulmonary end. Success rate was 100% (defined as successful closure without residual shunt). One patient had a renal vein thrombosis, which fully resolved with low-molecular-weight heparin anticoagulation. No tricuspid regurgitation or stenosis of the left pulmonary artery or the aorta was seen. One patient died of a superior caval vein obstruction with bilateral chylothorax related to a central catheter thrombosis 56 days after the procedure, unrelated to the catheter procedure.

CONCLUSION

In this prospective study, we describe a new technique to avoid tricuspid valve damage and facilitate delivery of the PAD device.

Molecular Mechanisms Underlying Remodeling of Ductus Arteriosus: Looking beyond the Prostaglandin Pathway

The ductus arteriosus (DA) is a physiologic vessel crucial for fetal circulation. As a major regulating factor, the prostaglandin pathway has long been the target for DA patency maintenance or closure. However, the adverse effect of prostaglandins and their inhibitors has been a major unsolved clinical problem. Furthermore, a significant portion of patients with patent DA fail to respond to cyclooxygenase inhibitors that target the prostaglandin pathway. These unresponsive medical patients ultimately require surgical intervention and highlight the importance of exploring pathways independent from this well-recognized prostaglandin pathway. The clinical limitations of prostaglandin-targeting therapeutics prompted us to investigate molecules beyond the prostaglandin pathway. Thus, this article introduces molecules independent from the prostaglandin pathway based on their correlating mechanisms contributing to vascular remodeling. These molecules may serve as potential targets for future DA patency clinical management.

Association of hemoglobin and spontaneous closure of the ductus arteriosus during the transitional period in very low birth weight infants

OBJECTIVES

To determine the association between plasma hemoglobin (HB) at three time-points (birth, postnatal days 0-3 and 0-10) and spontaneous closure of the ductus arteriosus (sDAC).

STUDY DESIGN

A retrospective case-control study of preterm infants born (2013-2016) between 24 and 29 weeks of gestational age (GA) was conducted in a level three perinatal center in Switzerland. We collected hemoglobin at birth, between days 0-3 and 0-10 in two distinct groups: (i) patients treated for a PDA and (ii) patients with spontaneous closure of the ductus arteriosus (sDAC). Antenatal and postnatal demographic data and neonatal morbidity were collected. Bivariate analysis was performed and a stepwise logistic regression was done to investigate factors associated with sDAC.

RESULTS

We reviewed the medical chart of 184 premature infants of whom 146 (79.3%) satisfied eligibility criteria. Of these, 74 (51%) were classified as sDAC. Patients with sDAC were older (GA: 28 vs 27, p < 0.001), more stable (clinical risk index for babies score (CRIB score): 2 vs 5, p < 0.001) and had better clinical outcomes than patients who received treatment for a PDA. Infants in the sDAC group had a higher level of hemoglobin during the first ten postnatal days. Multiple logistic regression analysis revealed that lower HB level (day 0-10) were associated with failure of sDAC (p < 0.05).

CONCLUSIONS

This is one of the first studies to highlight a potential association between hemoglobin during the transitional period and sDAC. The biological nature of this observation requires prospective clarification.

Early treatment versus expectant management of hemodynamically significant patent ductus arteriosus for preterm infants

BACKGROUND

Patent ductus arteriosus (PDA) is associated with significant morbidity and mortality in preterm infants. Nonsteroidal anti-inflammatory drugs (NSAIDs) are used to prevent or treat a PDA. There are concerns regarding adverse effects of NSAIDs in preterm infants. Controversy exists on whether early targeted treatment of a hemodynamically significant (hs) PDA improves clinical outcomes.

OBJECTIVES

To assess the effectiveness and safety of early treatment strategies versus expectant management for an hs-PDA in reducing mortality and morbidity in preterm infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2019, Issue 6) in the Cochrane Library; MEDLINE via PubMed (1966 to 31 May 2019), Embase (1980 to 31 May 2019), and CINAHL (1982 to 31 May 2019). An updated search was run on 2 October 2020 in the following databases: CENTRAL via CRS Web and MEDLINE via Ovid. We searched clinical trial databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials (RCT) and quasi-randomized trials.

SELECTION CRITERIA

We included RCTs in which early pharmacological treatment, defined as treatment initiated within the first seven days after birth, was compared to no intervention, placebo or other non-pharmacological expectant management strategies for treatment of an hs-PDA in preterm (< 37 weeks' postmenstrual age) or low birth weight (< 2500 grams) infants.

DATA COLLECTION AND ANALYSIS

We performed data collection and analyses in accordance with the methods of Cochrane Neonatal. Our primary outcome was all-cause mortality during hospital stay. We used the GRADE approach to assess the certainty of evidence for selected clinical outcomes.

MAIN RESULTS

We included 14 RCTs that enrolled 910 infants. Seven RCTs compared early treatment (defined as treatment initiated by seven days of age) versus expectant management and seven RCTs compared very early treatment (defined as treatment initiated by 72 hours of age) versus expectant management. No difference was demonstrated between early treatment versus expectant management (no treatment initiated within the first seven days after birth) for an hs-PDA for the primary outcome of 'all-cause mortality' (6 studies; 500 infants; typical RR 0.80, 95% CI 0.46 to 1.39; typical RD -0.02; 95% CI -0.07 to 0.03; moderate-certainty evidence), or other important outcomes such as surgical PDA ligation (4 studies; 432 infants; typical RR 1.08, 95% CI 0.65 to 1.80; typical RD -0.03; 95% CI -0.09 to 0.03; very low-certainty evidence), chronic lung disease (CLD) (4 studies; 339 infants; typical RR 0.90, 95% CI 0.62 to 1.29; typical RD -0.03; 95% CI -0.10 to 0.03; moderate-certainty evidence), severe intraventricular hemorrhage (IVH) (2 studies; 171 infants; typical RR 0.83,95% CI 0.32 to 2.16; typical RD -0.01; 95% CI -0.08 to 0.06; low-certainty evidence), and necrotizing enterocolitis (NEC) (5 studies; 473 infants; typical RR 2.34,95% CI 0.86 to 6.41; typical RD 0.04; 95% CI 0.01 to 0.08; low-certainty evidence). Infants receiving early treatment in the first seven days after birth were more likely to receive any PDA pharmacotherapy compared to expectant management (2 studies; 232 infants; typical RR 2.30, 95% CI 1.86 to 2.83; typical RD 0.57; 95% CI 0.48 to 0.66; low-certainty evidence). No difference was demonstrated between very early treatment versus expectant management (no treatment initiated within the first 72 hours after birth) for an hs-PDA for the primary outcome of 'all-cause mortality' (7 studies; 384 infants; typical RR 0.94, 95% CI 0.58 to 1.53; typical RD -0.03; 95% CI -0.09 to 0.04; moderate-certainty evidence) or other important outcomes such as surgical PDA ligation (5 studies; 293 infants; typical RR 0.88, 95% CI 0.36 to 2.17; typical RD -0.01; 95% CI -0.05 to 0.02; moderate-certainty evidence), CLD (7 studies; 384 infants; typical RR 0.83, 95% CI 0.63 to 1.08; typical RD -0.05; 95% CI -0.13 to 0.04; low-certainty evidence), severe IVH (4 studies, 240 infants; typical RR 0.64, 95% CI 0.21 to 1.93; typical RD -0.02; 95% CI -0.07 to 0.04; moderate-certainty evidence), NEC (5 studies; 332 infants; typical RR 1.08, 95% CI 0.53 to 2.21; typical RD 0.01; 95% CI -0.04 to 0.06; moderate-certainty evidence) and neurodevelopmental impairment (1 study; 79 infants; RR 0.27, 95% CI 0.03 to 2.31 for moderate/severe cognitive delay at 18 to 24 months; RR 0.54, 95% CI 0.05 to 5.71 for moderate/severe motor delay at 18 to 24 months; RR 0.54, 95% CI 0.10 to 2.78 for moderate/severe language delay at 18 to 24 months; low-certainty evidence). Infants receiving very early treatment in the first 72 hours after birth were more likely to receive any PDA pharmacotherapy compared to expectant management (4 studies; 156 infants; typical RR 1.64, 95% CI 1.31 to 2.05; typical RD 0.69; 95% CI 0.60 to 0.79; very low-certainty evidence). Very early treatment, however, shortened the duration of hospitalization compared to expectant management (4 studies; 260 infants; MD -5.35 days; 95% CI -9.23 to -1.47; low-certainty evidence).

AUTHORS' CONCLUSIONS

Early or very early pharmacotherapeutic treatment of an hs-PDA probably does not reduce mortality in preterm infants (moderate-certainty evidence). Early pharmacotherapeutic treatment of hs-PDA may increase NSAID exposure (low-certainty evidence) without likely reducing CLD (moderate-certainty evidence), severe IVH or NEC (low-certainty evidence). We are uncertain whether very early pharmacotherapeutic treatment of hs-PDA also increases NSAID exposure (very low-certainty evidence). Very early treatment probably does not reduce surgical PDA ligation, severe IVH or NEC (moderate-certainty evidence), and may not reduce CLD or neurodevelopmental impairment (low-certainty evidence). Additional large trials that specifically include preterm infants at the highest risk of PDA-attributable morbidity, are adequately powered for patient-important outcomes and are minimally contaminated by open-label treatment are required to explore if early targeted treatment of hs-PDA improves clinical outcomes. There are currently two trials awaiting classification and two ongoing trials exploring this question.

Effect of Beta 3 Adrenoreceptor Modulation on Patency of the Ductus Arteriosus

β3-adrenoreceptor (β3-AR), a G-protein coupled receptor, has peculiar regulatory properties in response to oxygen and widespread localization. β3-AR is expressed in the most frequent neoplasms, also occurring in pregnant women, and its blockade reduces tumor growth, indicating β3-AR-blockers as a promising alternative to antineoplastic drugs during pregnancy. However, β3-AR involvement in prenatal morphogenesis and the consequences of its blockade for the fetus remain unknown. In this study, after the demonstrated expression of β3-AR in endothelial and smooth muscle cells of ductus arteriosus (DA), C57BL/6 pregnant mice were acutely treated at 18.5 of gestational day (GD) with indomethacin or with the selective β3-AR antagonist SR59230A, or chronically exposed to SR59230A from 15.5 to 18.5 GD. Six hours after the last treatment, fetuses were collected. Furthermore, newborn mice were treated straight after birth with BRL37344, a β3-AR agonist, and sacrificed after 7 h. SR59230A, at the doses demonstrated effective in reducing cancer progression (10 and 20 mg/kg) in acute and chronic mode, did not induce fetal DA constriction and did not impair the DA ability to close after birth, whereas at the highest dose (40 mg/kg), it was shown to cause DA constriction and preterm-delivery. BRL37344 administered immediately after birth did not alter the physiological DA closure.

Utility of modified vascular corrosion casting technique in the diagnosis of fetal ductus arteriosus abnormalities

The anatomy of ductus arteriosus (DA) can be varied in different congenital heart defects (CHDs), and it is difficult to fully discover the DA and other associated cardiac anomalies by prenatal ultrasound. This study was aimed to use the modified vascular corrosion casting technique to prepare fetal cardiovascular casts with DA anomalies, assess the casting effectiveness in evaluating the great vessels of the fetal heart and investigate the utility of cardiovascular casting for the demonstration of fetal DA abnormalities. This retrospective study enrolled fourteen fetuses (23 to 28⁺² gestational weeks) with severe CHDs diagnosed by prenatal echocardiography and casting technique from January 2013 to July 2019. The sonographic features of DAs were carefully observed and other associated cardiovascular anomalies were also evaluated during the screening. The architectures of DAs and the whole cardiovascular system were observed and analyzed, and then the cast findings were compared with prenatal ultrasonic results. In fourteen cases, 18 ductal abnormities were indicated by prenatal echocardiography in fourteen cases, while 25 were revealed by casting. Cast findings included 4 cases of ductal stenosis, 1 case of ductal dilation, 6 cases of ductal circuity, 3 cases of right-sided ductus, 5 cases of anomalous ductal connection, 1 case of bilateral ductus and 5 cases of absent ductus. Cast findings consisted with ultrasound in 10 ductal abnormalities, revealed additional 15 ductal abnormalities miss-diagnosed by sonography, and corrected 6 abnormalities misdiagnosed prenatally. Meanwhile, 3 ductal abnormalities (reversed flow) could not be demonstrated by casts but only by ultrasound. Cast models can visually display the anatomical characteristics of ductus arteriosus, and could be successfully used in the demonstration of ductus abnormalities in fetuses with severe CHDs. Comparing with ultrasound, casting technique has its own superiority in exhibiting ductus abnormalities, especially in certain types such as course, origin and absence abnormalities of ductus.

Turning the Oxygen Dial: Balancing the Highs and Lows

Oxygen is both vital and toxic to life. Molecular oxygen is the most used substrate in the human body and is required for several hundred diverse biochemical reactions. The discovery of the PHD-HIF-pVHL system revolutionized our fundamental understanding of oxygen sensing and cellular adaptations to hypoxia. It deepened our knowledge of the biochemical underpinnings of numerous diseases, ranging from anemia to cancer. Cellular dysfunction and tissue pathology can result from a mismatch of oxygen supply and demand. Recent work has shown that mitochondrial disease models display tissue hyperoxia and that disease pathology can be reversed by normalization of excess oxygen, suggesting that certain disease states can potentially be treated by modulating oxygen levels. In this review, we describe cellular and organismal mechanisms of oxygen sensing and adaptation. We provide a revitalized framework for understanding pathologies of too little or too much oxygen.

Use of combination therapy with acetaminophen and ibuprofen for closure of the patent ductus arteriosus in preterm neonates

Objective

To compare effectiveness and safety of combination therapy (acetaminophen and ibuprofen) to monotherapy (ibuprofen, indomethacin, or acetaminophen alone) in treatment of the patent ductus arteriosus (PDA) in premature neonates.

Methods

This was a retrospective cohort study of neonates admitted to a tertiary-level neonatal intensive care unit. Included neonates were born at <32 weeks gestation and received pharmacotherapy for PDA closure. Based on the primary therapy received, our cohort was divided into the following four groups: indomethacin alone, ibuprofen alone, acetaminophen alone, and ibuprofen and acetaminophen (in combination). Baseline characteristics, effectiveness, safety, neonatal mortality, and morbidities rates between these groups were compared.

Results

One hundred and forty neonates were analyzed; 17 received combination therapy, and 123 neonates received monotherapy: 22 (17.9%) ibuprofen, 29 (23.6%) acetaminophen, and 72 (58.5%) indomethacin. The PDA closure rates were 41.7% for indomethacin, 41.2% for combination therapy, 37.9% for acetaminophen, and 31.8% for ibuprofen (P=0.100). Rates of adverse effects were comparable between the groups.

Conclusion

The rate of ductal closure was not different between combination therapy and monotherapy. The study did not demonstrate any increased adverse effects in the combination group. Future well-designed prospective clinical trials are needed to guide clinical practice.

Anaesthetic management and complications of transvascular patent ductus arteriosus occlusion in dogs

OBJECTIVE

To retrospectively analyse the anaesthetic management, complications and haemodynamic changes in a cohort of dogs undergoing transvascular patent ductus arteriosus (PDA) occlusion in a tertiary referral centre (from January 2017 to August 2018).

STUDY DESIGN

Retrospective study.

ANIMALS

A total of 49 client-owned dogs.

METHODS

Anaesthetic records of dogs with PDA that underwent transvascular occlusion of the ductus were reviewed. Anaesthetic complications evaluated included tachycardia [heart rate (HR) > 160 beats minute^-1], bradycardia (HR < 50 beats minute^-1), hypertension [systolic arterial pressure (SAP) > 150 mmHg], hypotension [mean arterial pressure (MAP) < 60 mmHg], hypothermia (<37 °C) and the presence of arrhythmias. Cardiovascular variables [HR and invasive SAP, MAP and diastolic arterial pressure (DAP)] at the time of occlusion device deployment (time 0) were compared with variables at 5 and 10 minutes after deployment. Descriptive statistics, Shapiro-Wilk test and repeated measures analysis of variance followed by a Dunnett's post hoc test were used to analyse the data (p < 0.05).

RESULTS

Crossbreed dogs were the most commonly represented followed by the Cavalier King Charles Spaniel. The median age was 8 (2-108) months, and female dogs were over-represented (65.3%). The most common American Society of Anesthesiologists score was III. Mean duration of anaesthesia was 96 ± 26 minutes and mean surgery time was 58 ± 21 minutes. Acepromazine with methadone was the most commonly used premedication combination (77.6%). Propofol was the most common induction agent (73.5%). General anaesthesia was maintained with isoflurane in oxygen in all dogs. Complications included hypotension (63%), hypothermia (34%), bradycardia (28%), arrhythmias (16%), hypertension (16%) and haemorrhage (2%). MAP and DAP increased significantly 10 minutes after device deployment compared with time 0.

CONCLUSIONS

and clinical relevance: Hypotension was the most common complication reported in dogs undergoing transvascular PDA occlusion. No major adverse events were documented.

Does exercise during pregnancy impact on maternal weight gain and fetal cardiac function? A randomized controlled trial

OBJECTIVE

To evaluate the association between physical exercise during pregnancy and maternal gestational weight gain and fetal cardiac function.

METHODS

This was a randomized controlled trial of women with a singleton pregnancy managed from the first trimester at the Hospital de Torrejón, Madrid, between November 2014 and June 2015. Women were randomized to either follow a supervised physical conditioning program, consisting of a 60-min session 3 days per week for the duration of pregnancy, or not attend any exercise program (controls). The primary outcome was maternal weight gain during pregnancy. Secondary outcomes included fetal cardiac function parameters evaluated at 20, 28 and 36 weeks' gestation, Cesarean section, preterm delivery, induction of labor and birth weight. A sample size of 45 in each group was planned to detect differences in maternal weight gain of at least 1 kg, with a power of > 80% and α of 0.05.

RESULTS

During the study period, 120 women were randomized into the exercise (n = 75) and control (n = 45) groups. Following exclusions, the final cohort consisted of 42 women in the exercise group and 43 in the control group. Baseline characteristics (maternal age, prepregnancy body mass index, parity, conception by in-vitro fertilization, Caucasian ethnicity, physical exercise prior to pregnancy and smoker) were similar between the two groups. No differences were found between the groups in maternal weight at 20, 28, 36 and 38 weeks' gestation or in weight gain at 38 weeks. However, the proportion of women with weight loss ≥ 9 kg at 6 weeks postpartum was higher in the exercise compared with the control group (68.2% vs 42.8%; relative risk 1.593; P = 0.02). The ductus arteriosus pulsatility index (DA-PI) at 20 weeks (2.43 ± 0.40 vs 2.26 ± 0.33, P < 0.05) and the ejection fraction (EF) at 36 weeks (0.85 ± 0.13 vs 0.81 ± 0.11, P < 0.05) were higher in the exercise compared with the control group. All other evaluated fetal cardiac function parameters were similar between the two groups.

CONCLUSIONS

Performing exercise during pregnancy is not associated with a reduction in maternal weight gain but increases weight loss at 6 weeks postpartum. Physical exercise during pregnancy is associated with increased fetal DA-PI at 20 weeks and EF at 36 weeks, which could reflect adaptive mechanisms. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Hypoxia-induced ARHGAP26 deficiency inhibits the proliferation and migration of human ductus arteriosus smooth muscle cell through activating RhoA-ROCK-PTEN pathway

The Rho family plays crucial roles in O₂ -induced vasoconstriction, cell proliferation, and migration. Rho GTPase-activating protein 26 (ARHGAP26) is a GTPase-activating protein for the small GTPases of the Rho family. Our previous studies have demonstrated that ARHGAP26 expression was significantly downregulated in patent human ductus arteriosus (DA) tissue. However, its role underlying the maintenance of DA patency is unclear. In this study, patent (fetal) and constricted (newborn) mouse DA tissues were harvested to confirm the differences in the levels of expression of ARHGAP26. Human DA smooth muscle cells (DASMCs) were isolated and cultured in vitro and used to test the function of ARHGAP26. The expression of ARHGAP26 was significantly lower in patent (fetal) than constricted (newborn) mouse DA. ARHGAP26-knocked-down human DASMCs showed reduced proliferation and migration, which are both crucial to anatomic closure of DA. Moreover, after culturing under hypoxic conditions, the expression of ARHGAP26 in human DASMCs was significantly lower and hypoxia-induced ARHGAP26 deficiency activated the phosphorylation level of phosphatase and tensin homolog (PTEN) in DASMCs by mediating the activity of RhoA and RhoA-associated kinase 1 (ROCK1). Use of Y27632, an inhibitor of ROCK which further reduces the phospholipid activity of PTEN can reverse the inhibitory effect of PTEN on the proliferation and migration of human DASMCs. This provides insight into the molecular regulation of the RhoA-ROCK-PTEN pathway in DA smooth muscle cells, which may be a suitable therapeutic target or diagnostic biomarker for perinatal DA tone management.

Pharmacotherapy for patent ductus arteriosus closure

Even though up to 60% of premature infants less than 28 weeks gestation develop persistent patent ductus arteriosus (PDA), there remains controversy regarding if, when, and how to close the PDA. Failure to close the PDA has been associated with significant morbidity but no cause-and-effect has been proven for short-term or long-term outcomes in modern times. Surgical closure has the advantage of eliminating the PDA, but short-term complications and long-term adverse outcomes are worrisome. Intravenous indomethacin has been the "gold standard" for pharmacologic treatment over the past 40 years with high closure rates and decreased incidence of severe intraventricular hemorrhage (IVH) and pulmonary hemorrhage with early treatment but without improvement in long-term outcomes and with risk of renal toxicity. Intravenous ibuprofen has less vasoconstrictive toxicity than indomethacin with comparable closure rates but without improvement in IVH and with hyperbilirubinemia risks. Earlier this decade, acetaminophen (paracetamol) was discovered to effectively close the PDA with good short-term safety profile. Although promising, acetaminophen treatment requires further studies regarding long-term safety as well as ideal dosing and route of administration.

Variations in ductus arteriosus Doppler parameters in different sonographic views during the second half of gestation

The aim of the present study was to compare the Doppler parameters of the fetal ductus arteriosus (DA) measured in the traditional longitudinal ductal arch (LDA) view and the newly introduced three vessels and trachea (3VT) plane of the fetal upper mediastinum. The peak systolic velocity (PSV), end-diastolic velocity (EDV), time-averaged maximum velocity (TAMXV) and velocity-time integral (VTI) measurements were taken for 52 fetuses with normal growth (including 29 females). The pulsatility index (PI) and resistance index (RI) were calculated. All parameters for each fetus were measured three times by the same sonographer in the LDA and the 3VT view, and the averages were taken to obtain the final value. Differences in the above values obtained from the LDA and 3VT views were analyzed and the correlation between the differences of all indices and the gestational age (GA) was evaluated using Pearson's linear coefficient of correlation. All of the values were characterized as normally distributed continuous variables by homogeneity of variance analysis. Slight increases in the PSV, EDV, TAMXV and VTI determined in the LDA view were identified compared with those in the 3VT view (P<0.05). Furthermore, these increases were identified to be independent of the GA (P>0.05). However, no significant differences in the impedance indices PI and RI were observed between the two sonographic planes (P>0.05). In conclusion, the LDA view provides a better chance than the 3VT view to obtain higher values of velocity parameters (PSV, EDV, TMAXV and VTI) within the fetal DA, and the differences are independent of the GA. However, no significant variations in the impedance indices PI and RI were observed between these two sonographic planes.

Umbilical cord blood metabolomics reveal distinct signatures of dyslipidemia prior to bronchopulmonary dysplasia and pulmonary hypertension

Pulmonary hypertension (PH) is a common consequence of bronchopulmonary dysplasia (BPD) and remains a primary contributor to increased morbidity and mortality among preterm infants. Unfortunately, at the present time, there are no reliable early predictive markers for BPD-associated PH. Considering its health consequences, understanding in utero perturbations that lead to the development of BPD and BPD-associated PH and identifying early predictive markers is of utmost importance. As part of the discovery phase, we applied a multiplatform metabolomics approach consisting of untargeted and targeted methodologies to screen for metabolic perturbations in umbilical cord blood (UCB) plasma from preterm infants that did ( n = 21; cases) or did not ( n = 21; controls) develop subsequent PH. A total of 1,656 features were detected, of which 407 were annotated by metabolite structures. PH-associated metabolic perturbations were characterized by reductions in major choline-containing phospholipids, such as phosphatidylcholines and sphingomyelins, indicating altered lipid metabolism. The reduction in UCB abundances of major choline-containing phospholipids was confirmed in an independent validation cohort consisting of UCB plasmas from 10 cases and 10 controls matched for gestational age and BPD status. Subanalyses in the discovery cohort indicated that elevations in the oxylipins PGE1, PGE2, PGF2a, 9- and 13-HOTE, 9- and 13-HODE, and 9- and 13-KODE were positively associated with BPD presence and severity. This expansive evaluation of cord blood plasma identifies compounds reflecting dyslipidemia and suggests altered metabolite provision associated with metabolic immaturity that differentiate subjects, both by BPD severity and PH development.

Conversion to thoracotomy of video-assisted thoracoscopic closure of patent ductus arteriosus

Introduction

Posterolateral thoracotomy was the access of choice in surgical treatment of patent ductus arteriosus (PDA) for many years before the introduction of video-assisted thoracoscopic surgery (VATS). The latter is thought to reduce postoperative pain and improve musculoskeletal system status. However, it carries a potential risk of conversion to thoracotomy.

Aim

To evaluate the rate, reasons and outcomes of VATS conversion to thoracotomy in surgical PDA patients.

Material and methods

From 2012 to 2017, 112 children were qualified for VATS closure of symptomatic PDA. Among them, 19 (16.9%) with the median age of 19.4 months required conversion to thoracotomy. The predominant reasons for conversion, early mortality and morbidity as well as late survival were evaluated.

Results

The overall conversion rate was 16.9% with an evident learning curve as it decreased significantly from more than 20% at the beginning to approximately 10% in the last 2 years. The predominant reasons were incomplete PDA closure (n = 6; 31.6%) followed by ductal bleeding after clip application (n = 5; 26.3%) and inadequate visualization (n = 5). One child died 48 h after the surgery due to acute cardiopulmonary failure (mortality 5.9%). All patients required postoperative chest tube insertion, and two of them developed postoperative pneumothorax. Neither deaths nor severe adverse events were noted throughout the follow-up period.

Conclusions

The rate of VATS PDA closure conversion to standard thoracotomy features a learning curve. Although it must be considered as a serious complication, probably it does not negatively affect either early the mortality rate or long-term survival.

Circulatory Insufficiency and Hypotension Related to the Ductus Arteriosus in Neonates

The biological role of the ductus arteriosus (DA) in neonates varies from an innocent bystander role during normal postnatal transition, to a supportive role when there is compromise to either systemic or pulmonary blood flow, to a pathological state in the presence of hemodynamically significant systemic to pulmonary shunts, as occurs in low birth weight infants. Among a wide array of clinical manifestations arising due to the ductal entity, systemic circulatory insufficiency and hypotension are of significant concern as they are particularly challenging to manage. An understanding of the physiologic interplay between the DA and the circulatory system is the key to developing appropriate targeted therapeutic strategies. In this review, we discuss the relationship of systemic hypotension to the DA, emphasizing the importance of critical thinking and a precise individual approach to intensive care support. We particularly focus on the variable states of hypotension arising directly due to a hemodynamically significant DA or seen in the period following successful surgical ligation. In addition, we explore the mechanistic contributions of the ductus to circulatory insufficiency that may manifest during the transitional period, states of maladapted transition (such as acute pulmonary hypertension of the newborn), and congenital heart disease (both ductal dependent and non-ductal dependent lesions). Understanding the dynamic modulator role of the ductus according to the ambient physiology enables a more precise approach to management. We review the pathophysiology, clinical manifestations, diagnosis, monitoring, and therapeutic intervention for the spectrum of DA-related circulatory compromise.

Unique aspects of the developing lung circulation: structural development and regulation of vasomotor tone

This review summarizes our current knowledge on lung vasculogenesis and angiogenesis during normal lung development and the regulation of fetal and postnatal pulmonary vascular tone. In comparison to that of the adult, the pulmonary circulation of the fetus and newborn displays many unique characteristics. Moreover, altered development of pulmonary vasculature plays a more prominent role in compromised pulmonary vasoreactivity than in the adult. Clinically, a better understanding of the developmental changes in pulmonary vasculature and vasomotor tone and the mechanisms that are disrupted in disease states can lead to the development of new therapies for lung diseases characterized by impaired alveolar structure and pulmonary hypertension.

Cerebral oxygenation and echocardiographic parameters in preterm neonates with a patent ductus arteriosus: an observational study

BACKGROUND

A haemodynamically significant patent ductus arteriosus (hsPDA) is clinically suspected and confirmed by echocardiographic examination. A hsPDA decreases cerebral blood flow and oxygen saturation by the ductal steal phenomenon.

AIM

To determine the relationship between echocardiographic parameters, cerebral oxygenation and a hsPDA in preterm infants.

METHODS

380 preterm infants (<32 weeks gestational age) born between 2008 and 2010 were included. Blinded echocardiographic examination was performed on the second, fourth and sixth day after birth. Examinations were deblinded when hsPDA was clinically suspected. Regional cerebral oxygen saturation (rScO₂) was continuously monitored by near-infrared spectroscopy during 72 h after birth, and afterwards for at least 1 h before echocardiography. Echocardiographic parameters included ductal diameter, end-diastolic flow in the left pulmonary artery, left atrium/aorta ratio and ductal flow pattern.

RESULTS

rScO₂ was significantly related only to ductal diameter over time. Mixed modelling analysed the course of rScO₂ over time, where infants were divided into four groups: a closed duct, an open haemodynamically insignificant duct (non-sPDA), a hsPDA, which was successfully closed during study period (SC hsPDA) or a hsPDA, which was unsuccessfully closed during study period (UC hsPDA). SC hsPDA infants showed the highest rScO₂ on day 6, while UC hsPDA infants had the lowest rScO₂ values.

CONCLUSIONS

Ductal diameter is the only echocardiographic parameter significantly related to cerebral oxygenation over time. Cerebral oxygenation takes a different course over time depending on the status of the duct. Low cerebral oxygenation may be suggestive of a hsPDA.

A novel approach to ductal spasm during percutaneous device occlusion of patent ductus arteriosus

Ductal spasm is a rare yet important complication of device occlusions of patent ductus arteriosus. Spasm may result in failure of the procedure, under-sizing of the device, or embolisation of the implanted device as the spasm resolves after the procedure. We describe a novel protocol that rapidly and completely reversed the spasm in eight prematurely born infants who experienced ductal spasm during cardiac catheterisations for patent ductus arteriosus occlusion. In total, eight infants born between 25 and 34 weeks of gestation presented for transcatheter patent ductus arteriosus occlusion between 13 and 87 months of age. All eight patients experienced ductal spasm either immediately before, during, or soon after induction of anaesthesia or only after entering the ductus arteriosus with a catheter. After detection of the spasm, the anaesthetist, in each case, changed the mode of anaesthesia from inhaled sevoflurane to total intravenous anaesthesia with propofol, reduced the inhaled oxygen fraction to 21%, and initiated a continuous intravenous infusion of prostaglandin E1. The first two steps (total intravenous anaesthesia and FiO2 0.21) resulted in only partial relaxation of the spasm. Complete relaxation was attained after intravenous prostaglandin E1 infusions of only 10-15 minutes' duration. While maintaining this protocol, six ducti were successfully occluded and two were considered to be unsuitable for device occlusion and were referred for surgery. Ductal spasm during transcatheter occlusion may be reliably resolved and the procedure safely completed by a simple anaesthetic protocol, including the continuous infusion of intravenous prostaglandin E1.

To evaluate the prevalence of symptomatic and non-symptomatic ductus arteriosus and accuracy of physical signs in diagnosing PDA in preterm infants using blinded comparison of clinical and echocardiographic findings during the first week of life: a prospective observational study from Iran

AIMS

To evaluate the prevalence of symptomatic and non-symptomatic ductus arteriosus (PDA) and accuracy of physical signs in diagnosing PDA in preterm infants using blinded comparison of clinical and echocardiographic findings during the first week of life.

METHODS AND MATERIAL

This prospective observational cross-sectional study enrolled 200 preterm infants, who underwent echocardiography on 4th-7th postnatal day. The neonates who were diagnosed to have PDA on echo were observed for clinical features of PDA to label it symptomatic PDA. Symptomatic PDA was defined as detecting one or all of these symptoms in a neonate with PDA: bounding pulse, pericardial hyperactivity, systolic or continuous murmur.

RESULTS

Forty-five infants had PDA on echocardiography. 66.7% neonates with PDA were symptomatic and the most prevalent symptom in them was heart murmur (100%) either alone or combined with other clinical features. Isolated murmur was seen in 31.2%, murmur and hyperdynamic precordium was seen in 8.8%, murmur and bounding pulses were seen in 6.67% and all three features simultaneously were seen in 20% of infants. The sensitivity of murmur for diagnosing symptomatic PDA was highest.

CONCLUSION

Presence of murmur is the most important clinical feature for diagnosis of symptomatic PDA and has good specificity.

Cerebral Microemboli Detection and Differentiation During Transcatheter Closure of Patent Ductus Arteriosus

The aim of this prospective study was to determine the frequency and composition of cerebral microemboli in a pediatric population, during transcatheter closure of patent ductus arteriosus (PDA). Multifrequency transcranial Doppler was used to monitor cerebral blood flow velocity (CBFV) and detect microembolic signals (MES) in the middle cerebral artery in 23 patients (median age 18 months). MES were automatically identified and differentiated according to composition; gaseous or solid. The procedure was divided into five periods: Arterial catheterization; venous catheterization; ductal catheterization; angiography; device placement and release. Timing of catheter manipulations and MES were registered and compared. MES were detected in all patients. The median number of signals was 7, (minimum 1, maximum 28). Over 95 % of all MES were gaseous. 11 % were detected during device placement while 64 % were detected during angiographic studies, significantly higher than during any other period (P < 0.001). There was a moderate correlation between the number of MES and volume of contrast used, (R = 0.622, P < 0.01). There was no correlation with fluoroscopic time or duration of procedure. This is the first study to investigate the timing and composition of cerebral microemboli during PDA occlusion. Microemboli were related to specific catheter manipulations and correlated with the amount of contrast used.

Effectiveness and safety of treatments used for the management of patent ductus arteriosus (PDA) in preterm infants: a protocol for a systematic review and network meta-analysis

INTRODUCTION

Management of patent ductus arteriosus (PDA) in preterm infants is one of the most controversial topics in neonatal medicine. The availability of different pharmacotherapeutic options often poses a practical challenge to the practising neonatologist as to which one to choose as a therapeutic option. Our objectives are to determine the relative merits of the available pharmacotherapeutic options for the management of PDA.

METHODS AND ANALYSIS

We will conduct a systematic review of all randomised controlled trials evaluating the use of intravenous or oral: indomethacin, ibuprofen and acetaminophen for the treatment of PDA in preterm infants. The primary outcome is failure of closure of the PDA. Secondary outcomes are neonatal mortality, need for surgical closure, duration of ventilator support, chronic lung disease, intraventricular haemorrhage, periventricular leukomalacia, necrotising enterocolitis, gastrointestinal bleeding, time to full enteral feeds and oliguria. We will search Medline, Embase and Cochrane Central Register of Controlled Trials (CENTRAL) as well as grey literature resources. Two reviewers will independently screen titles and abstracts, review full texts, extract information, and assess the risk of bias (ROB) and the confidence in the estimate (with Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach). Subgroup analysis according to gestational age, birth weight, different doses of interventions, time of administration of the first dose of the intervention, and echocardiographic definition of haemodynamically significant PDA and ROB are planned. We will perform a Bayesian network meta-analysis to combine the pooled direct and indirect treatment effect estimates for each outcome, if adequate data are available.

ETHICS AND DISSEMINATION

The results will help to reduce the uncertainty about the safety and effectiveness of the interventions, will identify knowledge gaps or will encourage further research for other therapeutic options. Therefore, its results will be disseminated through peer-reviewed publications and conference presentations. On the basis of the nature of its design, no ethics approval is necessary for this study.

TRIAL REGISTRATION NUMBER

CRD42015015797.

Neurodevelopmental Outcome at 2 Years of Age according to Patent Ductus Arteriosus Management in Very Preterm Infants

BACKGROUND

Patent ductus arteriosus (PDA) is a condition frequently found in very preterm infants, and its treatment remains a subject of debate. Furthermore, there are only a few studies available that have examined the impact of these treatments on the neurological outcome of the patient.

OBJECTIVE

To evaluate the neurodevelopmental outcome of PDA treatment on preterm infants born between 24+0 and 28+6 weeks of gestation.

METHODS

We conducted an observational multicentric cohort study (LIFT Cohort). We compared three groups of patients according to their PDA treatment strategy: medical treatment with ibuprofen, surgical ligation, and no treatment. The neurodevelopmental outcome was assessed with a physical examination and cognitive function evaluation at 2 years of age. A propensity score was used to reduce bias in the analysis.

RESULTS

Between 2003 and 2011, 857 infants (91.3%) were evaluated at 2 years of corrected age and included in the analysis: 248 received ibuprofen treatment (29%), 104 had PDA surgical ligation (12%), and 505 did not receive any PDA treatment (59%). Surgical ligation of PDA was significantly associated with neurodevelopmental impairment at 2 years of age (adjusted odds ratio = 2.2; 95% confidence interval: 1.4-3.4).

CONCLUSION

We found an association between PDA surgical ligation and a nonoptimal neurodevelopmental outcome at 2 years of age for preterm infants born before 29 weeks of gestation. These results suggest that if surgical ligation is unavoidable, particular attention should be given to the patient's neurodevelopmental follow-up.

Prenatal constriction of the ductus arteriosus following maternal diclofenac medication in the third trimester

We describe a case of a 21-year-old primigravida at 36 weeks' gestation who was admitted to a local hospital because of abdominal pain. She was prescribed a total of six doses of diclofenac 50 mg over 2 days. One day later, there was difficulty registering the fetal heartbeats on cardiotocography. Ultrasound examination revealed a fetus with ascites and pathological flow over the tricuspid valve. The patient was referred to a tertiary centre for fetal medicine. Fetal echocardiography revealed, in addition to ascites and tricuspid regurgitation, a constricted ductus arteriosus, dilated right ventricle and reduced flow in the pulmonary artery. Immediate caesarean section resulted in an excellent neonatal outcome.

Ductal closure with radiofrequency energy: the first in-human report

BACKGROUND

Vascular obstruction is one of the complications of radiofrequency ablation. Following our previous report on the use of radiofrequency energy for vascular closure in an animal model in this journal, we herein present the first ever in-human report. Patient and method The patient was a 3-year-old boy, who received a permanent endocardial pacemaker for congenital complete heart block. He also had a conical patent ductus arteriosus. The ductus was occluded with radiofrequency energy on the arterial side with no complications.

CONCLUSION

Closure of patent ductus arteriosus and probably other problematic small vessels could be achieved with radiofrequency energy. Further experience will elucidate the future scope of this novel technique.