Ductal Flow Research Articles

Short-term effects of antenatal betamethasone on fetal cardiovascular and circulation status: A quasi-experimental observational (before-after) study.

The administration of antenatal corticosteroid is a standard treatment to reduce the rate of perinatal mortality and morbidity; however, there is limited evidence regarding the potential effects of betamethasone on the constriction of the ductus arteriosus (DA). This study aimed to investigate the short-term effects of antenatal betamethasone on fetal cardiovascular and circulation status. This quasi-experimental observational (before-after) study was conducted on 32 singleton fetuses. The participants were healthy pregnant women with a diagnosis of placenta accreta spectrum who were eligible for 2 doses of betamethasone and referred to prenatal care clinic, Vali-E-Asr hospital, Tehran, Iran from January 2021-May 2022. The results of fetal echocardiography and Doppler sonography were compared before and after the administration of antenatal corticosteroid therapy. Following betamethasone injection, significant increases were observed in peak systolic and diastolic velocity of the DA without constriction of the DA (p 0.001, p = 0.002 respectively). However, no significant changes were observed in right ventricular function, tricuspid valve function, Doppler of ductus venous, and peak systolic velocity of the aortic isthmus (p 0.05). Doppler examination of the uterine, umbilical, and middle cerebral arteries also showed no significant changes (p 0.05). Considering the benefits of antenatal corticosteroid therapy, its administration seems reasonable in preterm births. The transient changes in ductal blood flow are not prohibitive.

OR1-5 | Pre-Catheterization CT Scanning Aids in the Selection of PDA Stent Length for Ductal Dependent Pulmonary Blood Flow

OR1-5 | Pre-Catheterization CT Scanning Aids in the Selection of PDA Stent Length for Ductal Dependent Pulmonary Blood Flow

Maternal supplementation with docosahexaenoic acid does not cause constriction of fetal ductus arteriosus: randomized controlled trial.

Docosahexaenoic acid (DHA) is recommended routinely in pregnancy to promote fetal development. DHA has anti-inflammatory activity, but its effects on the fetal heart and circulation are unknown. This study aimed to investigate whether maternal DHA supplementation in the third trimester affects maternal prostaglandin levels and fetal ductus arteriosus flow dynamics. This was a double-blind randomized controlled trial with parallel groups conducted between 2018 and 2021. Pregnant women aged over 18 years with a normal fetus at 27-28 weeks' gestation showing no cardiac/extracardiac anomalies or ductal constriction were eligible for the trial. Women consuming substances with a known inhibitory effect on prostaglandin metabolism, such as non-steroidal anti-inflammatory drugs and polyphenol-rich foods, were excluded. The intervention group received oral supplementation of omega-3 with 450 mg/day of DHA for 8 weeks and the placebo group received capsules of soy lecithin for 8 weeks. Anthropometric measurements, assessment of polyphenol and omega-3 consumption, fetal morphological ultrasound examination, fetal Doppler echocardiographic examination and blood sample collection were performed at the start of the study and the latter two were repeated at follow-up. Prostaglandin E2 (PGE2) level and echocardiographic parameters were compared between the intervention and placebo groups and between baseline and follow-up. A total of 24 participants were included in each group. After 8 weeks, there were no significant differences between the intervention and placebo groups in maternal serum PGE2 level or Doppler echocardiographic parameters of ductal flow. No case of ductus arteriosus constriction was observed. The expected intragroup changes in cardiac morphology, as a result of advancing gestation, were present. Maternal DHA supplementation in the third trimester at a clinically recommended dose did not result in inhibition of PGE2 or constriction of the ductus arteriosus. These findings should be confirmed in postmarket surveillance studies with larger patient numbers in order to test the full safety profile of DHA and provide robust clinical reassurance. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Creating a flow restrictor in ductal stenting: a novel technique.

Ductal stenting has transformed the care of neonates with ductal-dependent critical CHD, especially in low-income countries. In small infants, a 3.5- or 4-mm stent may lead to too much pulmonary blood flow resulting in pulmonary oedema. We herein presented a novel technique to restrict ductal stent flow in a premature neonate with pulmonary atresia and intact ventricular septum following radiofrequency perforation of the pulmonary valve.

Analysis of echocardiographic features and postnatal management of fetal pulmonary valve stenosis

Objective: To investigate the echocardiographic features, consistency of diagnosis between fetal and postnatal periods and postnatal clinical outcomes of fetal pulmonary valve stenosis (PS) with different degrees. Methods: This study was a retrospective cohort study comprising 108 cases of fetal PS diagnosed during the fetal period and followed up postnatally at Xinhua Hospital, Shanghai Jiaotong University School of Medicine from November 2012 to February 2023. Echocardiographic characteristics, including morphological and hemodynamic features were collected for all fetuses who were then were followed up to at least 6 months after birth. One-way analysis of variance and Kruskal-Wallis test were used to compare the differences in the echocardiographic features among fetuses with different degrees of PS. Subsequently, McNemar test was used to assess the consistency of diagnosis between the fetal and postnatal periods. Furthermore, Logistic regression analysis was applied to explore the risk factors for neonatal intervention in fetuses with moderate PS and the receiver operating characteristic (ROC) curve was utilized to ascertain the optimal cut-off value for continuous variables. Results: The age of the mothers of the 108 fetuses at the initial assessment was (30.8±4.0) years, and the gestational age was 26.5 (24.6, 30.0) weeks. The fetuses were categorized into mild (17 cases), moderate (49 cases), and severe groups (42 cases) based on the initial echocardiographic features. Mild PS was characterized by valve thickening and hyperechogenicity combined with systolic flow acceleration or dilation of main pulmonary artery. Moderate PS exhibited both restricted valve motion and a colorful blood flow pattern at the valve orifice. The peak flow velocities of fetuses with moderate and critical PS were notably higher than those in the mild group ((2.66±0.86) and (2.77±1.30) vs. (1.43±0.59)m/s, F=14.52, P<0.001). In critical PS, all cases showed retrograde ductal flow, with a significantly higher proportion of a small right ventricle compared to the mild and moderate PS (42.9% (18/42) vs. 0 and 2.0% (1/49), χ2=31.73, P<0.001). The proportion of severe tricuspid regurgitation was also higher (35.7% (15/42) vs. 0 and 10.2% (5/49), χ2=36.94, P<0.001). Compared to mild and severe PS, the consistency of diagnosis between fetal and postnatal periods in moderate PS was lower (40.8% (20/49) vs.13/17 and 80.3% (35/42), χ2=12.45, P=0.006). The systolic flow velocity was identified as an independent risk factor for neonatal intervention in fetuses with moderate PS (OR=7.21, 95%CI2.11-24.62). A flow velocity of ≥2.18 m/s in second trimester and ≥3.15 m/s in third trimester indicated the necessity of neonatal intervention for fetal moderate PS. Among the 108 fetuses, 68 underwent surgical intervention and all survived. Additionally, 39 fetuses were regularly followed up. A sole non-surgical fatality occurred, leading to a 6-month survival rate of 99.1% (107/108). Conclusions: Various degrees of fetal PS demonstrate distinctive morphological and hemodynamic alterations in echocardiography. The disparity in severity between the postnatal and fetal stages requires ongoing monitoring for fetal PS. The prognosis for fetal PS is generally favorable.

Persistent pulmonary hypertension of the newborn infant (PPHN) due to premature closure of the ductus arteriosus (DA)

Abstract Objectives To describe the course of an infant with persistent pulmonary hypertension of the newborn (PPHN) secondary to premature closure of the ductus arteriosus (DA), a very rare phenomenon which can lead to adverse clinical outcomes. Case presentation A term infant was diagnosed with severe PPHN with echocardiographic features noted at 6 h after birth which included supra-systemic pulmonary pressures, severe isolated right ventricle (RV) hypertrophy, poor RV dysfunction and no ductal flow in the context of a structurally normal heart. There was maternal use of low-dose aspirin in pregnancy due to preeclampsia. There is a known association between use of prostaglandin synthase inhibitors such as aspirin with ductal closure leading to increased RV pressure. Treatment was commenced with positive pressure ventilation, inhaled nitric oxide (iNO) and milrinone. There was a limited response to iNO necessitating increasing the concentration of milrinone with a marked improvement in oxygenation. Following commencement of sildenafil, inhaled nitric oxide was gradually weaned and stopped in the third week and the infant extubated. The infant was discharged home on oral sildenafil at four weeks of age with no respiratory or feeding support. Echocardiographic features of raised right sided pressures persisted, but with reduced RV hypertrophy and septal flattening and improved RV function. Oral sildenafil was subsequently weaned and stopped at four months of age. Conclusions A severe form of PPHN due to premature closure of the DA requires early discussion with the cardiologist. The use of milrinone and sildenafil can lead to a favourable outcome.

A-331 Prenatal Maternal First Trimester Screening and Establishing the Multiple of Medians of Double Marker Tests in Tertiary Care Hospital in India

Abstract Background Down's syndrome, Edwards syndrome, and Patau syndrome (trisomy 21, 18, 13 respectively) in a fetus can be screened by prenatal testing using the maternal serum. Prenatal testing can provide an accurate assessment of the patient's risk of carrying an affected fetus. Double marker testing which includes the levels of free β- Human Chorionic Gonadotropin and Pregnancy Associated Plasma Protein A in the maternal serum along with the measurement of Crown Rump Length and Nuchal Translucency helps in determining the risk of Trisomy 21. Prenatal testing prevents the need for invasive methods. Methods This is a study conducted in Kokilaben Dhirubhai Ambani Hospital and Research Centre, Mumbai, Maharashtra, India from January 2012 to December 2018 for 628 pregnant women. The data for 1st trimester was divided into 3 groups: 11 to 11.6 weeks(86 patients), 12 to 12.6 weeks (421 patients), and 13 to 13.6 weeks (121 patients) based on their gestational age. This study included the determination of levels of double markers like free β- Human Chorionic Gonadotropin and Pregnancy Associated Plasma Protein A using maternal serum along with the ultrasound studies which included the Crown Rump Length and Nuchal Translucency measurements. Additional factors like a history of chromosomal abnormalities, smoking habits, insulin-dependent diabetes, and other dichotomous markers like the presence of nasal bone, abnormal ductal flow, and tricuspid regurgitation are also considered in calculating the risk. The concentration of biochemical parameters was expressed in Multiple of Median (MOM) with respect to maternal age. The risk assessment was analyzed using SSDW 5 and SSDW 6 software and the cut-off was set at 1:250 for age as well as trisomy 21, 18, and 13. Results The total number of positive patients for trisomy 21 and trisomy 13/18 were represented in percentage which turned out to be 2.86% and 1.11% respectively in association with the gestational age, dichotomous markers, double marker test, and ultrasound studies. The MOM for β-HCG, PAPPA, and NT were compared in SSDW5 and SSDW6. The mean β-HCG MOM negative and positive patients (trisomy 21) were found to be 1.34 ± 0.945 and 2.74 ± 1.685 respectively indicating the levels increase above normal. The mean PAPPA MOM negative and positive patients (trisomy 21) were found to be 1.47 ± 0.9125 and 0.77 ± 7667 respectively indicating the levels decrease below the normal. The NT mom for negative and positive patients was 0.91 ± 1879 and 1.88 ± 1.6508 respectively which suggests that the thickness of nuchal translucency increases with the increased risk for trisomy 21. Conclusion 18 out of 628 patients tested positive for trisomy 21 which was assessed using double marker testing and ultrasound studies. The levels of free β-HCG were seen to be increased and the levels of PAPPA were decreased in the patients who showed higher risks. Prenatal testing provides an advantage for early detection of this disorder.

Patent ductus arteriosus stenting as therapeutic bridge in a patient with type A3 truncus arteriosus variant with multiple comorbidities.

Type A3 truncus arteriosus describes pulmonary atresia with non-confluent mediastinal pulmonary arteries in which one pulmonary artery arises from a patent ductus arteriosus and the contralateral pulmonary artery from the aorta resulting in ductal dependent pulmonary blood flow. We describe a premature neonate with caudal regression syndrome and type A3 truncus arteriosus who was palliated with a ductal stent allowing completion of a prolonged neonatal ICU hospitalisation for multiple comorbidities.

Combination therapy for patent ductus arteriosus in preterm infants: Echocardiographic changes and clinical use

BackgroundSearching for the optimal therapeutic strategy for hemodynamically significant Patent Ductus Arteriosus in preterm infants is ongoing. A novel approach utilizing a combination of ibuprofen and acetaminophen has generated interest, with speculations that this approach may be more effective than standard single-agent therapy. ObjectivesOur objectives were to compare the echocardiographic parameters before and after the combination therapy and to describe its use (primary vs. rescue), effectiveness, and side effects. MethodsThis was a retrospective cohort review of preterm infants born <33 weeks gestation who were admitted to a tertiary-level neonatal intensive care unit between January 1, 2012, and December 31, 2020. Included infants received combination pharmacotherapy with ibuprofen and acetaminophen for ductal closure, either as a primary course (1st line use) or as a rescue (2nd or 3rd course), and had echocardiographic measurements pre-and post-therapy. Baseline characteristics, echocardiographic parameters of ductus arteriosus hemodynamics before and after combination therapy, the effectiveness of treatment, and adverse effects were examined. ResultsDuring the study period, 32 infants received combination therapy, with 17 (53 %) receiving it as a primary course and 16 (47 %) receiving it as a rescue course after trying another pharmacological agent. Complete echocardiographic data were available for 17 infants included in the study (11 primary and 6 rescues). The overall treatment success rate was 41 %. The primary course had a better treatment success rate (55 %) than the rescue course (17 %). Echocardiographic analysis showed that the primary course treatment resulted in significantly lower ductal diameter (p = 0.013), higher ductal flow Doppler velocities (p = 0.037), more restrictive shunt pattern (p = 0.005), and decreasing ductus arteriosus significance score (p = 0.016). Such improvement in hemodynamic significance was not noted when combination therapy was used as rescue therapy. ConclusionPrimary combination therapy with ibuprofen and acetaminophen resulted in considerable improvements in echocardiographic markers of hemodynamically significant ductus arteriosus. Future trials exploring the safety and efficacy of this treatment as a first-line option are required.

Comparison of Patent Ductus Arteriosus Stenting and Blalock-Taussig Shunt in Ductal Dependent Blood Flow Congenital Heart Disease and Decreased Pulmonary Blood Flow.

Congenital ductal-dependent cyanotic congenital heart disease (CHD) is a group of diseases that require early intervention during early infancy or the neonatal period. In this study, we compared the effectiveness, safety, and side effects of stenting patent ductus arteriosus versus a modified Blalock-Taussig (BT) shunt. Thirty-six neonates and infants with cyanotic CHD who were <6 months old and were not suitable for complete surgery were admitted to Chamran Hospital in Isfahan and enrolled in this prospective longitudinal cross-sectional study. Ductal stenting (DS) was performed in 18 patients and BT shunt in 18 patients. Data were collected and compared in these patients. Age, height, and weight were lower in the DS group compared to the shunt group (1.28 ± 0.46 vs. 2.50 ± 0.51 months, 53.22 ± 1.80 vs. 56.11 ± 1.67 cm, 3.38 ± 0.45 vs. 4.98 ± 0.57 kg, respectively P < 0.001). The duration of the intensive care unit stay as well as hospital stay in patients in the DS group was much shorter than the shunt group (1.33 ± 0.68 vs. 2.83 ± 0.70 days, 3.33 ± 0.68 vs. 9.55 ± 0.51, P < 0.001, respectively). In both groups, the diameter of the pulmonary branches increased after the procedure compared to before the procedure (P < 0.001). Furthermore, the patient's hemoglobin was significantly decreased compared to before the procedure (P < 0.001). In both groups, one patient died in the postprocedure period. In ductal stent group one patient died in catheterization lab and in shunt group died 48 hours after surgery. There was no significant difference in postprocedural complications between the two groups. Duct stents can be used as an effective and safe method in duct-dependent cyanotic CHD patients who are not suitable candidates for complete surgery. As operators become proficient, this method can be a good alternative to BT shunts with fewer complications.

Haemodynamic and clinical variables after surgical systemic to pulmonary artery shunt placement versus arterial ductal stenting.

Transcatheter stenting of the arterial duct is an alternative to surgical systemic to pulmonary artery shunt in neonates with parallel circulation. The current study compares haemodynamic and laboratory values in these patients for the first 48 hours after either intervention. Neonates with ductal dependent pulmonary blood flow who underwent surgical shunt placement or catheter-based arterial ductal stent placement between January 2013 and January 2022 were identified. Haemodynamic variables included heart rate, blood pressure, near infrared spectroscopy, central venous pressure, vasoactive inotropic score, and arterial saturation. Laboratory variables collected included blood urea nitrogen, serum creatinine, and serum lactate. Variables were collected at baseline, upon post-procedural admission, 6 hours after admission, 12 hours after admission, and 48 hours after admission. Secondary outcomes included post-procedural mechanical ventilation duration, post-procedural hospital length of stay, need for reintervention, need for extracorporeal membrane oxygenation, cardiac arrest, and inpatient mortality. Of the 52 patients included, 38 (73%) underwent shunt placement while 14 (27%) underwent a stent placement. Heart rates, renal oxygen extraction ratio, and cerebral oxygen extraction ratio were significantly lower in the stent group (p = <0.01, 0.01, and < 0.01, respectively).Haemoglobin and vasoactive inotropic scores were significantly lower in the stent group (p = <0.01, <0.01, respectively). The stent group had increased risk for cardiac arrest (p = 0.04). Patients who undergo arterial ductal stent placement have lower heart rates, haemoglobin, renal oxygen extraction ratio, cerebral oxygen extraction ratio, and vasoactive inotropic score in the first 48 hours post-procedure compared to patients with shunt placement.

Abstract 15341: Persistent Fifth Arch as an Aortopulmonary Connection in a Case of Tetralogy of Fallot

Persistent fifth aortic arch is a heterogeneous vascular anomaly with variable anatomical presentations and physiological consequences. This unusual embryological remnant represents a management challenge, particularly in critical right sided obstructive heart lesions where accurate delineation of sources of pulmonary blood flow is essential. This is a newborn 2 kg premature male born at 34 weeks of gestation with prenatally diagnosed tetralogy of Fallot. Post-natal echocardiogram confirmed diagnosis with evidence of moderate-to-severe pulmonary stenosis, restrictive ventricular septal defect, and a right aortic arch. CT angiogram ordered to delineate the head and neck vessel anatomy showed an exceedingly rare finding of an isolated connection of the left subclavian artery (LSCA) to the main pulmonary artery (MPA) via a left sided ductus arteriosus. Blood flowed from the common carotid arteries, through the circle of Willis, and, in a retrograde direction, into the LSCA. Prostaglandin E was initiated due to concern for ductal dependent pulmonary blood flow, but after clinical observation it was discontinued without subsequent onset of cyanosis. Repeat echocardiograms were reassuring in showing persistence of the left ductus arteriosus. The patient was discharged home at 5 weeks-old and at 4 months-old he underwent complete repair after developing progressive desaturations and worsening sub-valvar and valvar pulmonary stenosis. The surgical repair included ventricular septal defect closure, transannular patch, extensive right ventricular myomectomy and reimplantation of LSCA onto the left common carotid artery. The post-operative course was uncomplicated. This rare case of persistent fifth aortic arch with retrograde flow to the LSCA demonstrates the complementary roles of noninvasive imaging modalities in guiding medical therapy and surgical management. This unusual blood flow pattern and initial concern for duct dependent pulmonary blood flow complicated early management, but a conservative approach with repeat imaging allowed for eventual complete repair.

Paradoxical Continuous Left-to-Right Ductal Shunt during Circulatory Collapse due to Ductal Closure in an Infant with Duct-Dependent Systemic Circulation

Duct-dependent systemic circulation is accompanied by a right-to-left ductal shunt, at least during systole. Although observations of paradoxical continuous left-to-right shunts in duct-dependent systemic circulation have been reported, the mechanism remains unclear. We report a continuous left-to-right ductal shunt throughout the cardiac cycle during the initial recovery phase from circulatory collapse and right ventricular (RV) dysfunction due to ductal closure in an infant with hypoplastic left heart and severe aortic coarctation. Further recovery improved his RV function and changed the ductal flow from continuous left-to-right to bidirectional, which is usually seen in duct-dependent systemic circulation. Marked RV dysfunction may contribute to the continuous left-to-right ductal shunt. A continuous left-to-right ductal shunt should not be used to rule out duct-dependent systemic circulation.

Tetralogy of Fallot in the fetus - from diagnosis to delivery. 18-year experience of a tertiary Fetal Cardiology Center.

Tetralogy of Fallot (TOF) is a common congenital heart disease but very heterogeneous in terms of detailed cardiac anatomy, associated malformations, and genetic anomalies, especially when assessed prenatally. We aimed to analyze the clinical spectrum of TOF in the prenatal period, including detailed cardiac morphology, coexisting anomalies, and their impact on short-term neonatal outcome. We also assessed changing trends in the prenatal diagnostic workup of TOF. A retrospective cohort study including fetuses diagnosed with TOF between 2002 and 2019 was conducted in a tertiary Fetal Cardiology Center. Medical records and echocardiographic examinations were reviewed to collect demographic, sonographic, and genetic data. Among 326 TOF fetuses, 237 (73%) had pulmonary stenosis (TOF-PS), 72 (22%) pulmonary atresia (TOF-PA), and 17 (5%) absent pulmonary valve (TOF-APV). The yearly number of diagnoses increased during the study period, with decreasing fetal age at the time of diagnosis. Extracardiac malformations were found in 172 (53%) fetuses, cardiovascular malformations in 159 (49%), and genetic anomalies in 99 (39% of the tested group). Hypoplastic thymus, right aortic arch, and polyhydramnios were sonographic markers of microdeletion 22q11. Left-to-right ductal flow was predictive of postnatal ductal dependency. The perinatal outcome was dependent on the presence of associated anomalies and disease subtype, with TOF-APV having the worst prognosis. Extracardiac and genetic anomalies are common in fetuses with TOF, and, together with disease subtype and ductal flow assessment, they impact the perinatal management and outcomes. Genetic testing with array comparative genomic hybridization should be offered in all cases.

P163 BOTALLO ARTERIAL DUCT SURGICALLY TREATED IN URGENCY

Abstract The Botallo arterial duct connects the pulmonary artery and the aorta during fetal life; after birth there is a progressive fall in pulmonary resistance mediated by the increase in oxygen concentration and the decrease in prostaglandins with a vasodilating action. In these physiological conditions, spontaneous closure of the duct is observed within the first 48–72 hours of life. In the preterm infant the patency of the Botallo duct is very frequent due to the peculiar anatomical and physiological characteristics of the preterm infant. The incidence of PDA is higher the lower the birth weight and gestational age are. We report a case of Manuel, a baby born at 32 weeks of gestational age from elective CT due to transverse presentation with difficulty in extraction and anhydrosis. 37–year–old mother hospitalized for reduction of amniotic fluid (AFI 85 index) with no apparent rupture of the membranes, for which she began a cycle of glucocorticoids 12mg twice a day. At birth, the weight of the child was 1,780 g, length 42 cm, skull circumference 28 cm, absence of valid respiratory activity, bradycardia (78 bpm) APGAR index of 4. At 5 ‘of life he was intubated with a 3 Fi rush tube fixed to 8 cm from the buccal rim with neopuff with PIP 20 cmH2O, PEEP 5 cmH2O, FiO2 0.40, transferred to the NICU, placed in the incubator, connected to the ventilator and ventilated with A/C mode with PIP 23 cmH2O, PEEP 5 cmH2O, FiO2 0, 40 –&amp;gt; 0.60, given surfactant alfa 200 mg/kg. Anemic, plasma and red blood cells were administered multiple times; infectious disease tests (aerobic–anaerobic haemocolutre, umbilical culture, culture of OT tubes, BAL, ear and throat swabs) were negative. After 3 days, systolic heart murmur appeared 2–3/6 radiated to the axilla. The echocardium showed the persistence of the Duct of Botallo, with a mosaic jet in the pulmonary artery and a “growing” ductal flow pattern. He started treatment with indomethacin 0.2 mg/kg every 12 hours x 3 doses, but on echocardiographic control the picture remained unchanged. At 16 days of age, the newborn was transferred to the Bambin Gesù in Rome and underwent cardiac surgery via the left posterolateral thoracotomy to close the arterial duct with a Weck clip. The post–operative course was regular. Manuel was discharged 2.5 months after birth in good general conditions, good growth–weight, with a weight of 2460 g.

Divergent effects of initial ventilation with delayed cord clamping on systemic and pulmonary arterial flows in the birth transition of preterm lambs.

A current view that delayed cord clamping (DCC) results in greater haemodynamic stability at birth than immediate cord clamping (ICC) is based on comparison of DCC vs. ICC followed by an asphyxial (∼2min) cord clamp-to-ventilation (CC-V) interval. More recent data suggest that relatively minor perinatal differences in heart rate and blood pressure fluctuations exist between DCC and ICC with a non-asphyxial (<45s) CC-V interval, but it is unknown how ventricular output and central arterial blood flow effects of DCC compare with those of non-asphyxial ICC. Anaesthetized preterm fetal lambs instrumented with flow probes on major central arteries were ventilated for 97 (7) s (mean (SD)) before DCC at birth (n=10), or underwent ICC 40 (6) s before ventilation (n=10). Compared to ICC, initial ventilation and DCC was accompanied by (1) redistribution of a similar level of ascending aortic flow away from cephalic arteries and towards the aortic isthmus after ventilation; (2) a lower right ventricular output after cord clamping that was redistributed towards the lungs, thereby maintaining the absolute contribution of this output to a similar increase in pulmonary arterial flow after birth; and (3) a lower descending thoracic aortic flow after birth, related to a more rapid decline in phasic right-to-left ductal flow only partially offset by increased aortic isthmus flow. However, systemic arterial flows were similar between DCC and non-asphyxial ICC within 5min after birth. These findings suggest that compared to non-asphyxial ICC, initial ventilation with DCC transiently redistributed central arterial flows, resulting in lower perinatal systemic arterial, but not pulmonary arterial, flows. KEY POINTS: A current view that delayed cord clamping (DCC) results in greater haemodynamic stability at birth than immediate cord clamping (ICC) is based on comparison of DCC vs. ICC with an asphyxial (∼2min) cord clamp-to-ventilation (CC-V) interval. Recent data suggest that relatively minor perinatal differences in heart rate and blood pressure fluctuations exist between DCC and ICC with a non-asphyxial (<45s) CC-V interval, but how central arterial blood flow effects of DCC compare with those of non-asphyxial ICC is unknown. Anaesthetized preterm fetal lambs instrumented with central arterial flow probes underwent initial ventilation for ∼90s before DCC at birth, or ICC for ∼40s before ventilation. Compared to non-asphyxial ICC, initial ventilation with DCC redistributed central blood flows, resulting in lower systemic, but not pulmonary, arterial flows during this period of transition. This flow redistribution was transitory, however, with systemic arterial flows similar between DCC and non-asphyxial ICC within minutes after birth.

Case Report: Aortic Regurgitation of Postocclusion and Long-Term Outcome Following PDA Correction in an Adult Dog

A 9-year-old intact female Maltese dog was admitted for further evaluation of previously diagnosed patent ductus arteriosus (PDA). The dog showed severe coughing and exercise intolerance. On physical examination, a grade VI/VI continuous heart murmur was auscultated. Thoracic radiography demonstrated cardiomegaly, pulmonary overcirculation, and moderate bronchointerstitial pattern. Echocardiography revealed severe dilation of the left ventricle and atrium, decreased left ventricular contractility, and left-to-right PDA. On electrocardiography (ECG), R amplitude was increased. Computed tomographic angiography revealed type IIA PDA. The serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration was >10,000 pmol/L. Transarterial occlusion was performed and the Amplatz® Canine Duct Occluder was successfully deployed. On echocardiography 48 h after the procedure, aortic regurgitation (AR) and residual ductal flow were noted. Long-term follow-up on clinical signs, physical examination, radiography, echocardiography, ECG, and serum NT-proBNP were evaluated until 30 months after correction of PDA. The clinical indices of physical examination, thoracic radiography, echocardiography, ECG, and serum NT-proBNP concentration were improved, although the postocclusion AR and residual ductal flow persisted. The dog followed up without clinical signs for 41 months following the correction. To our knowledge, this is the first case report to demonstrate quite a long time of follow-up (41 months) in an older dog with transarterial occlusion of PDA with postocclusion AR and residual flow.

Transcatheter closure of patent ductus arteriosus in 11 dogs and one cat after incomplete or aborted surgical ligation

ObjectiveTo describe the characteristics and outcomes of transcatheter patent ductus arteriosus (PDA) occlusion after incomplete or aborted surgical ligation in dogs and cats. AnimalsTwelve client-owned animals (11 dogs and one cat). Materials and methodsThis retrospective study describes data from animals with aborted or incomplete surgical PDA ligation that subsequently underwent transcatheter closure using endovascular methods. Patient demographics, reason for incomplete or aborted surgery, complications, and method of transcatheter occlusion were recorded. Data are presented as mean ± standard deviation or median (interquartile range), where appropriate. ResultsFor all cases, median age at surgery was 12.2 months (4.9–15.1 months) and at catheterization was 15.4 months (8.9–21.9 months), with 79 days (29–209 days) between surgical and interventional procedures. Median weight at catheterization was 4.5 kg (2.5–12.6 kg). Reasons for failed surgical ligation included hemorrhage during ductal dissection in seven dogs, residual flow in four dogs, and inability to identify the ductus in one cat. Transcatheter closure was successfully performed using a canine duct occluder in eight dogs, transarterial coil embolization in two dogs, and transvenous coil embolization in one dog and one cat. Metallic hemoclips partially obscured angiographic findings in three cases with prior surgical hemorrhage but did not prevent transcatheter closure. In all cases, ductal flow was successfully attenuated, with no or trace residual shunting on angiography and complete occlusion the following day on echocardiography. ConclusionsWhen surgery is unsuccessful, either owing to hemorrhage or residual flow, transcatheter closure of PDA is feasible, even in small patients.

Rastelli operation for double outlet right ventricle, pulmonary atresia with ductal dependent pulmonary flow

Double outlet right ventricle (DORV) with or without pulmonary atresia is a common indication for Rastelli operation. We very infrequently perform this surgery in our center. Here, we report a case of a ten-year-old girl who recently underwent Rastelli operation and patent ductus arteriosus (PDA) ligation for DORV, pulmonary atresia with ductal dependent pulmonary circulation by using custom-made valved conduit

Effects of Patent Ductus Arteriosus on the Hemodynamics of Modified Blalock-Taussig Shunt Based on Patient-Specific Simulation.

The question of preserving the patent ductus arteriosus (PDA) during the modified Blalock–Taussig shunt (MBTS) procedure remains controversial. The goal of this study was to investigate the effects of the PDA on the flow features of the MBTS to help with preoperative surgery design and postoperative prediction. In this study, a patient with pulmonary atresia and PDA was included. A patient-specific three-dimensional model was reconstructed, and virtual surgeries of shunt insertion and ductus ligation were performed using computer-aided design. Computational fluid dynamics was utilized to analyze the hemodynamic parameters of varied models based on the patient-specific anatomy and physiological data. The preservation of the PDA competitively reduced the shunt flow but increased total pulmonary perfusion. The shunt flow and ductal flow collided, causing significant and complicated turbulence in the pulmonary artery where low wall shear stress, high oscillatory shear index, and high relative residence time were distributed. The highest energy loss was found when the PDA was preserved. The preservation of PDA is not recommended during MBTS procedures because it negatively influences hemodynamics. This may lead to pulmonary overperfusion, inadequate systemic perfusion, and a heavier cardiac burden, thus increasing the risk of heart failure. Also, it seems to bring no benefit in terms of reducing the risk for thrombosis.