Percutaneous Patent Ductus Arteriosus (PDA) Closure in Very Preterm Infants: Feasibility and Complications

Patent ductus arteriosus in preterm infants: is early transcatheter closure a paradigm shift?

The optimal management approach of the patent ductus arteriosus (PDA) in premature infants remains uncertain owing the lack of evidence for long-term benefits and the limited analyses of the complications of medical and surgical interventions to date. In recent years, devices suitable to plug the PDA of premature infants (including extremely low birthweight, <1000 g) have become available and several trials have demonstrated successful and safe transcatheter PDA closure (TCPC) in this population. Whether TCPC represents a paradigm shift in PDA management that will result in improved short- and long-term outcomes, less bronchopulmonary dysplasia, improved neurodevelopment, or better long term renal function remains to be seen. Careful rigorous study of the potential benefits of TCPC in this highly vulnerable population in the context of well-designed adequately powered trials is needed prior to widespread adoption of this approach.

Early prediction of spontaneous Patent Ductus Arteriosus (PDA) closure and PDA-associated outcomes: a prospective cohort investigation

BACKGROUND

Patent ductus arteriosus (PDA), the most commonly diagnosed cardiovascular condition in preterm infants, is associated with increased mortality and harmful long-term outcomes (chronic lung disease, neurodevelopmental delay). Although pharmacologic and/or interventional treatments to close PDA likely benefit some infants, widespread routine treatment of all preterm infants with PDA may not improve outcomes. Most PDAs close spontaneously by 44-weeks postmenstrual age; treatment is increasingly controversial, varying markedly between institutions and providers. Because treatment detriments may outweigh benefits, especially in infants destined for early, spontaneous PDA closure, the relevant unanswered clinical question is not whether to treat all preterm infants with PDA, but whom to treat (and when). Clinicians cannot currently predict in the first month which infants are at highest risk for persistent PDA, nor which combination of clinical risk factors, echocardiographic measurements, and biomarkers best predict PDA-associated harm.

METHODS

Prospective cohort of untreated infants with PDA (n=450) will be used to predict spontaneous ductal closure timing. Clinical measures, serum (brain natriuretic peptide, N-terminal pro-brain natriuretic peptide) and urine (neutrophil gelatinase-associated lipocalin, heart-type fatty acid-binding protein) biomarkers, and echocardiographic variables collected during each of first 4 postnatal weeks will be analyzed to identify those associated with long-term impairment. Myocardial deformation imaging and tissue Doppler imaging, innovative echocardiographic techniques, will facilitate quantitative evaluation of myocardial performance. Aim1 will estimate probability of spontaneous PDA closure and predict timing of ductal closure using echocardiographic, biomarker, and clinical predictors. Aim2 will specify which echocardiographic predictors and biomarkers are associated with mortality and respiratory illness severity at 36-weeks postmenstrual age. Aim3 will identify which echocardiographic predictors and biomarkers are associated with 22 to 26-month neurodevelopmental delay. Models will be validated in a separate cohort of infants (n=225) enrolled subsequent to primary study cohort.

DISCUSSION

The current study will make significant contributions to scientific knowledge and effective PDA management. Study results will reduce unnecessary and harmful overtreatment of infants with a high probability of early spontaneous PDA closure and facilitate development of outcomes-focused trials to examine effectiveness of PDA closure in "high-risk" infants most likely to receive benefit.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03782610. Registered 20 December 2018.

Follow-up after Percutaneous Patent Ductus Arteriosus Occlusion in Lower Weight Infants

OBJECTIVES

To describe longer term outcomes for infants <6 kg undergoing percutaneous occlusion of the patent ductus arteriosus (PDA).

STUDY DESIGN

This was a retrospective cohort study of infants <6 kg who underwent isolated percutaneous closure of the PDA at a single, tertiary center (2003-2017). Cardiopulmonary outcomes and device-related complications (eg, left pulmonary artery obstruction) were examined for differences across weight thresholds (very low weight, <3 kg; low weight, 3-<6 kg). We assessed composite measures of respiratory status during and beyond the initial hospitalization using linear mixed effects models.

RESULTS

In this cohort of lower weight infants, 92 of 106 percutaneous occlusion procedures were successful. Median age and weight at procedure were 3.0 months (range, 0.5-11.1 months) and 3.7 kg (range, 1.4-5.9 kg), respectively. Among infants with pulmonary artery obstruction on initial postprocedural echocardiograms (n = 20 [22%]), obstruction persisted through hospital discharge in 3 infants. No measured variables were associated with device-related complications. Rates of oxygenation failure (28% vs 8%; P < .01) and decreased left ventricular systolic function (29% vs 5%; P < .01) were higher among very low weight than low weight infants. Pulmonary scores decreased (indicating improved respiratory status) following percutaneous PDA closure.

CONCLUSIONS

Percutaneous PDA occlusion among lower weight infants is associated with potential longer term improvements in respiratory health. Risks of device-related complications and adverse cardiopulmonary outcomes, particularly among very low weight infants, underscore the need for continued device modification. Before widespread use, clinical trials comparing percutaneous occlusion vs alternative treatments are needed.

Descriptive review of patent ductus arteriosus ligation by video-assisted thoracoscopy in pediatric population: 7-year experience

Background

Less invasive procedures such as video-assisted thoracoscopic surgery (VATS) are desirable for patent ductal artery (PDA) ligation when pharmacologic or conservative approaches fail. Studies done on VATS-PDA ligation showed better outcomes when compared to open thoracotomies, however, complication rates remain conflicting. Learning curve can be a postulated reason which may also precludes the acceptability. We therefore sought to report our single centered 7-year experience of PDA closure with VATS.

Methods

Single centered retrospective study of 127 patients who underwent PDA ligature with VATS from February 2012 to October 2018. The cohort was divided into two groups, i.e., 2012-2014 (early phase) and 2015-2018 (late phase) and were further compared. Early and late outcomes, including mortality and morbidity, were analyzed.

Results

The included patients had a mean age of 1.7 years. Among them, preterm infants accounted for 38.6%, there was no operative mortality. Six deaths (4.7%) occurred during in-hospital stay, predominantly in the neonatal intensive care unit (NICU) due to massive cerebral bleeding and cardiopulmonary failure. Overall conversion rate to thoracotomy was 16.5%. It decreased from 20% in early phase to less than 5% in late phase. Fifty patients (39.4%) required transfer to the NICU. The mean in-hospital stay for the remainders was only 2.2±1.6 days. All but two patients discharged home survived follow-up period without any adverse events and nobody among non-converted cases expressed concerns regarding chest deformity. A 5-year probability of survival estimated according to the Kaplan-Meier curve was 93.6%.

Conclusions

VATS is a safe as well as efficient method for closure of PDA that ensures satisfactory late cosmetic results. Postoperative mortality and extended hospital stay may be attributed to prematurity. Although learning curve exists it does not affect the safety and late outcomes.

Practice variation in the management of patent ductus arteriosus in extremely low birth weight infants in the United States: Survey results among cardiologists and neonatologists

BACKGROUND

Patent ductus arteriosus (PDA) is highly prevalent in extremely low birth weight (ELBW), preterm infants. There are diverse management approaches for the PDA in ELBW infants. The objectives of this research were to identify current PDA management practices among cardiologists and neonatologists in the United States, describe any significant differences in management, and describe areas where practices align.

METHODS

A survey of 10 questions based on the management of PDA in ELBW infants was conducted among 100 prominent neonatologists from 74 centers and 103 prominent cardiologists from 75 centers. Among the cardiologists, approximately 50% were interventionists who perform transcatheter PDA closures (TCPC). Fisher's exact test was performed to compare practice variations among neonatologists and cardiologists. A potentially biased audience including a combination of health care providers belonging to cardiology, neonatology, and surgery were also surveyed during the International PDA Symposium. The results of this survey were not included for statistical comparison, due to this audience being potentially influenced by the Symposium.

RESULTS

Statistically significant differences were identified between neonatologists and cardiologists regarding the impact of PDA closure on morbidity and mortality, with 80% cardiologists responding that it does vs 54% of neonatologists (P < 0.001), the need for PDA closure (P < .001), and the preferred method of PDA closure if indicated (P < .001). There was agreement between neonatologists and cardiologists on symptomatic therapy; however more neonatologists favored watchful waiting over intervention in contrast to more cardiologists favoring intervention over observation (77% vs 95%, P < .001). Survey responses also identified a need for further training and research on TCPC.

CONCLUSION

Neonatologists and cardiologists have notable differences in managing PDA, and continued discussion across cardiology and neonatology has the potential to facilitate more of a consensus on best management practices. Further investigation is needed to identify outcomes in transcatheter PDA closure, particularly in ELBW infants.

Interventional Treatment of Cardiac Emergencies in Children with Congenital Heart Diseases

Cardiac emergencies in children represent an extremely important issue in medical practice. In general, interventional treatment could be optional in many situations, however it can be indicated in emergency conditions. There are many diseases at pediatric age that can benefit from interventional treatment, thus reducing the surgical risks and subsequent complications. Balloon atrioseptostomy, patent ductus arteriosus (PDA) closure, percutaneous or hybrid closure of a ventricular septal defect, pulmonary or aortic valvuloplasty, balloon angioplasty for aortic coarctation, implantation of a stent for coarctation of the aorta, for severe stenosis of the infundibulum of the right ventricle, or for PDA correction are among the procedures that can be performed in emergency situations. This review aims to present the current state of the art in the field of pediatric interventional cardiology.

Practice for preterm patent ductus arteriosus; focusing on the hemodynamic significance and the impact on the neonatal outcomes

Hemodynamically significant preterm patent ductus arteriosus (PDA) affects mortality; comorbidities such as necrotizing enterocolitis, intraventricular hemorrhage, and bronchopulmonary dysplasia; and adverse long-term neurodevelopmental outcomes in preterm infants, particularly in very low birth weight infants. However, recent studies have indicated that there is no consensus on the causal relationship between PDA and neonatal outcomes, the benefit of PDA treatment, the factors guiding the need for treatment, and optimal treatment strategies. Such uncertainty has resulted in wide variations in practice for treating preterm PDA between units, regions, and nations. Nowadays, there has been a paradigm shift to more conservative treatment for preterm PDA, and suggestions regarding selective management of preterm PDA considering risk factors and hemodynamic significance are increasing. Neonatologist-performed echocardiography and advances in modalities to assess hemodynamic significance such as biologic markers and near-infrared spectroscopy also help improve the efficacy of selective treatment of preterm PDA.

Transcatheter Closure of a Huge Ductus Arteriosus in a Severely Ill Neonate

Hemodynamically significant patent ductus arteriosus (PDA) in preterm infants increases morbidity and mortality. Here we describe a 12-day-old neonate with a huge PDA who developed pulmonary hemorrhage following disseminated intravascular clotting and multiple organ failure. Medical treatment or surgical ligation could not be performed because of the patient's poor condition. Transcatheter closure using a commercially available device (Amplatzer Vascular Plug II) successfully treated the huge PDA without major complications. The Amplatzer Vascular Plug II approach might become a new option for PDA closure in small infants, including those who are critically ill.

Use of Amplatzer vascular plugs and Amplatzer duct occluder II additional sizes for occlusion of patent ductus arteriosus: A multi-institutional study

BACKGROUND

Variable patent ductus arteriosus (PDA) morphology and the need to close PDAs in small size patients has led physicians to use Amplatzer Vascular Plugs (AVP) and recently available Amplatzer Duct Occluder II - Additional Sizes (ADO II AS). The purpose of this study was to analyze the safety, efficacy, and complication rates of the ADO II AS and AVPs, specifically AVP II.

METHODS

All patients undergoing PDA closure with an AVP or ADO II AS from 2011 to 2016 were included. Clinical, echocardiographic, and angiographic data were collected and reviewed.

RESULTS

Four hundred and sixty-nine patients were included. Median age was 27 months (0.75-852) and the median weight was 11.4 kg (1-92). There were 51 patients ≤5 kg. Type A PDA was most common in 48% (n = 225), followed by type E (27.5%, n = 129), type D (13%, n = 61), type C (10.2%, n = 48), and type B (1.3%, n = 6). Devices included AVP II (n = 421), ADO II AS (n = 30), and AVP IV (n = 18), left pulmonary artery stenosis occurred in 4.3% (n = 20). One patient required surgery for severe stenosis; the remaining cases were mild and required no intervention. Device embolization occurred in 3 patients (10%) with the ADO II AS. Successful device closure was achieved in 98.9% of cases.

CONCLUSIONS

The AVP II was highly effective for closing PDAs in smaller babies with varying morphologies and is safe when used in small sized patients with relatively low risk of complications. More studies are warranted to clarify the risks of ADO II AS.

Catheter-based closure of the patent ductus arteriosus in lower weight infants

Risks associated with drug therapy and surgical ligation have led health care providers to consider alternative strategies for patent ductus arteriosus (PDA) closure. Catheter-based PDA closure is the procedure of choice for ductal closure in adults, children, and infants ≥6kg. Given evidence among older counterparts, interest in catheter-based closure of the PDA in lower weight (<6kg) infants is growing. Among these smaller infants, the goals of this review are to: (1) provide an overview of the procedure; (2) review the types of PDA closure devices; (3) review the technical success (feasibility); (4) review the risks (safety profile); (5) discuss the quality of evidence on procedural efficacy; (6) consider areas for future research. The review provided herein suggests that catheter-based PDA closure is technically feasible, but the lack of comparative trials precludes determination of the optimal strategy for ductal closure in this subgroup of infants.

Recent advances in cardiac catheterization for congenital heart disease

The field of pediatric and adult congenital cardiac catheterization has evolved rapidly in recent years. This review will focus on some of the newer endovascular technological and management strategies now being applied in the pediatric interventional laboratory. Emerging imaging techniques such as three-dimensional (3D) rotational angiography, multi-modal image fusion, 3D printing, and holographic imaging have the potential to enhance our understanding of complex congenital heart lesions for diagnostic or interventional purposes. While fluoroscopy and standard angiography remain procedural cornerstones, improved equipment design has allowed for effective radiation exposure reduction strategies. Innovations in device design and implantation techniques have enabled the application of percutaneous therapies in a wider range of patients, especially those with prohibitive surgical risk. For example, there is growing experience in transcatheter duct occlusion in symptomatic low-weight or premature infants and stent implantation into the right ventricular outflow tract or arterial duct in cyanotic neonates with duct-dependent pulmonary circulations. The application of percutaneous pulmonary valve implantation has been extended to a broader patient population with dysfunctional ‘native’ right ventricular outflow tracts and has spurred the development of novel techniques and devices to solve associated anatomic challenges. Finally, hybrid strategies, combining cardiosurgical and interventional approaches, have enhanced our capabilities to provide care for those with the most complex of lesions while optimizing efficacy and safety.

Percutaneous closure of a large patent ductus arteriosus in a preterm newborn weighing 1400 g without using arterial sheath: an innovative technique

Percutaneous closure of patent ductus arteriosus is well established in infants weighing >5 kg, but data regarding outcome of preterm especially very low birth weight infants is minimal. Although surgical ligation of patent ductus arteriosus is the preferred and well-accepted modality of treatment after failure of drug therapy in preterm infants, it has also got its own demerits in such a small and fragile subset. Device closure in infants weighing <1.5 kg is rarely attempted because of high chances of complications, especially acute arterial injury due to the arterial sheath. We received a 1.4-kg ventilator-dependent infant for closure of large patent ductus arteriosus. Percutaneous closure of patent ductus arteriosus was done successfully and the infant was discharged on room air with a weight of 1.8 kg. We present here an innovative technique in which successful patent ductus arteriosus device closure was done in a 1.4-kg infant without using arterial sheath.

Transcatheter Closure of Arterial Duct in Infants < 6 kg: Amplatzer Duct Occluder Type I vs Amplatzer Duct Occluder II Additional Sizes

Transcatheter closure of arterial duct (AD) remains challenging in low-weight patients and using Amplatzer Duct Occluder devices is still considered off-label in infants < 6 kg. This study aimed to report a large, single-center experience of percutaneous AD closure in infants < 6 kg as well as to compare the most frequently used devices, Amplatzer Duct Occluder type I (ADO I) and Amplatzer Duct Occluder type II Additional Sizes devices (ADO II-AS) (St. Jude Medical Corp, St. Paul, MN, USA). From March 2000 to March 2017, among the 762 patients submitted to percutaneous closure of AD at our Institution, 33 were infants < 6 kg (age 4.8 ± 2.1 months; weight 5.0 ± 0.9 kg). Fourteen patients (45%) underwent ADO I (Group I) and 19 patients ADO II-AS (Group II) device implantation. AD diameter was 2.6 ± 0.8 (range 1.5-4.0) mm resulting in QP/QS of 2.6 ± 0.0.9 (range 1.1-4.5). Successful device deployment was achieved in all patients without procedural morbidity or mortality. Procedural and fluoroscopy times were not significantly different between the groups. However, total X-ray absorbed dose was significantly higher in Group I (121 ± 69 vs 29 ± 16 mGy/cm², p < 0.01). Immediate, 24 h, and mid-term (46 ± 37 months, median 39) complete occlusion were recorded in 72.7, 90.9, and 97% of patients, respectively without significant difference between the groups. In conclusion, transcatheter closure of AD with Amplatzer Duct Occluder devices is feasible, safe, and effective also in infants less than 6 kg, without significant difference between the most commonly used devices, namely, ADO I and ADO II-AS.

Surgical Ligation Versus Percutaneous Closure of Patent Ductus Arteriosus in Very Low-Weight Preterm Infants: Which are the Real Benefits of the Percutaneous Approach?

Percutaneous treatment of patent ductus arteriosus (PDA) in extreme premature infants is technically difficult, and therefore, often not consider as an alternative to surgery. The main objective of our work was to compare respiratory status prior and post ductal closure and morbi-mortality, in our series of preterm infants with percutaneous PDA closure versus surgical ligation in the same time-period. Retrospective review of all premature infants submitted to percutaneous and surgical PDA closure from January 2011 to December 2016. All the antenatal, perinatal, and postnatal characteristics were collected. The main outcome was the assessment of the pulmonary status before and after ductal closure using a pulmonary score. Secondary outcomes included moderate-severe disability in neurodevelopment, death before discharge, moderate-severe chronic lung disease, and morbidity at discharge. 25 patients with a mean weight of 1330 g (± 280) underwent percutaneous closure of PDA with ADO-II-AS, and a total of 53 underwent surgical ligation. 28/53 with similar gestational age, birth weight, and procedure weight to those in the percutaneous group, were selected to perform the comparative study. Ductal closure (percutaneous and surgical) resulted in improved respiratory status. However, percutaneous group achieved a fastest respiratory improvement, than surgical group. The surgical closure group associated higher morbidity among survivors (HIV, number of sepsis, need, and duration of inotropics post-interventionism). The incidence of recurrent laryngeal nerve palsy among the surgical group was 17%. Percutaneous closure of PDA in carefully selected low-weight preterm infants is a safe and reliable alternative to surgical ligation.

Keeping an Open Mind: Cognitive Bias in the Evaluation of an Infant with Posterior-Lateral Rib Fractures

A four-month-old former premature male is incidentally found to have posterior-lateral rib fractures during evaluation of a febrile illness. This finding led to the initiation of a workup for nonaccidental trauma. A thorough history and physical exam ultimately led to the diagnosis, which was not related to abuse. This case highlights a rare sequela of patent ductus arteriosus repair, cautions medical teams to remain aware of how cognitive bias can affect diagnostic decision-making, and emphasizes the importance of a thorough history, physical exam, and medical record review in cases of suspected nonaccidental trauma.

Transcatheter Occlusion of the Patent Ductus Arteriosus in 747 Infants <6 kg: Insights From the NCDR IMPACT Registry

OBJECTIVES

The authors sought to identify risk factors associated with major adverse events (MAEs) in infants <6 kg undergoing transcatheter patent ductus arteriosus (PDA) occlusion.

BACKGROUND

Transcatheter PDA occlusion is among the safest of interventional cardiac procedures in adults and older children, but use among infants <6 kg has not been characterized adequately.

METHODS

Using the IMPACT (IMproving Pediatric and Adult Congenital Treatments) registry, we identified infants <6 kg undergoing transcatheter PDA occlusion (January 1, 2011, to March 1, 2015). Using mixed-effects multivariate regression, the authors assessed characteristics predictive of MAE or composite failure (procedural failure or MAE). Individual safety metrics (e.g., embolization, malposition) were also examined for differences across weight thresholds: extremely low weight (LW) (<2 kg), very LW (2 to <4 kg), and LW (4 to <6 kg).

RESULTS

Transcatheter PDA occlusion was attempted in 747 infants <6 kg at 73 hospitals. Rate of procedural success was 94.3%. MAEs were observed in 12.6% of cases; the most common events were acute arterial injury and device embolization in 3.5% and 2.4% of cases, respectively. Younger age (<30 days) was associated with greater risk of a MAE (risk ratio: 3.3; 95% confidence interval: 1.5 to 7.6) and composite failure (risk ratio: 3.0; 95% confidence interval: 1.4 to 6.7). Risk of embolization was higher among extremely LW (10.5%) than very LW or LW infants (1.6% and 2.5%, respectively; p = 0.050).

CONCLUSIONS

Among infants <6 kg, transcatheter PDA occlusion is technically feasible, but risks of MAE are noteworthy. These findings may help inform patient selection and procedural approach for transcatheter PDA occlusion and direct targeted research efforts to support the practice of evidence-based medicine.

Recent advances in pediatric interventional cardiology

During the last 10 years, there have been major technological achievements in pediatric interventional cardiology. In addition, there have been several advances in cardiac imaging, especially in 3-dimensional imaging of echocardiography, computed tomography, magnetic resonance imaging, and cineangiography. Therefore, more types of congenital heart diseases can be treated in the cardiac catheter laboratory today than ever before. Furthermore, lesions previously considered resistant to interventional therapies can now be managed with high success rates. The hybrid approach has enabled the overcoming of limitations inherent to percutaneous access, expanding the application of endovascular therapies as adjunct to surgical interventions to improve patient outcomes and minimize invasiveness. Percutaneous pulmonary valve implantation has become a successful alternative therapy. However, most of the current recommendations about pediatric cardiac interventions (including class I recommendations) refer to off-label use of devices, because it is difficult to study the safety and efficacy of catheterization and transcatheter therapy in pediatric cardiac patients. This difficulty arises from the challenge of identifying a control population and the relatively small number of pediatric patients with congenital heart disease. Nevertheless, the pediatric interventional cardiology community has continued to develop less invasive solutions for congenital heart defects to minimize the need for open heart surgery and optimize overall outcomes. In this review, various interventional procedures in patients with congenital heart disease are explored.

Percutaneous Patent Ductus Arteriosus (PDA) Closure During Infancy: A Meta-analysis

CONTEXT

Patent ductus arteriosus (PDA) is a precursor to morbidity and mortality. Percutaneous (catheter-based) closure is the procedure of choice for adults and older children with a PDA, but use during infancy (<1 year) is not well characterized.

OBJECTIVE

Investigate the technical success and safety of percutaneous PDA closure during infancy.

DATA SOURCES

Scopus, Web of Science, Embase, PubMed, and Ovid (Medline) were searched through December 2015 with no language restrictions.

STUDY SELECTION

Publications needed to clearly define the intervention as percutaneous PDA closure during infancy (<1 year of age at intervention) and must have reported adverse events (AEs).

DATA EXTRACTION

The study was performed according to the Systematic Reviews and Meta-Analysis checklist and registered prospectively. The quality of the selected studies was critically examined. Data extraction and assignment of AE attributability and severity were independently performed by multiple observers. Outcomes were agreed on a priori. Data were pooled by using a random-effects model.

RESULTS

Thirty-eight studies were included; no randomized controlled trials were found. Technical success of percutaneous PDA closure was 92.2% (95% confidence interval [CI] 88.8-95.0). Overall AE and clinically significant AE incidence was 23.3% (95% CI 16.5-30.8) and 10.1% (95% CI 7.8-12.5), respectively. Significant heterogeneity and publication bias were observed.

LIMITATIONS

Limitations include lack of comparative studies, lack of standardized AE reporting strategy, and significant heterogeneity in reporting.

CONCLUSIONS

Percutaneous PDA closure during infancy is feasible and associated with few catastrophic AEs; however, the limitations constrain the interpretability and generalizability of the current findings.

Transcatheter closure of PDA in premature babies less than 2 kg

Objective:

Our hypothesis was that percutaneous PDA closure in babies less than 2 kg was a safe and effective method. The aim of this study is to share our experience in transcatheter PDA closure in infants whose body weight is less than 2 kg in order to support our hypothesis.

Methods:

Between July 1997 and October 2014, 382 percutaneous PDA closures were done in our center. Nineteen patients who weighed less than 2 kg were included in this retrospectively study. The other inclusion criteria were 1) being symptomatic and PDA was thought as a possible contributor of medical state and 2) persistence of PDA after medical closure treatment. Patients who had sepsis and bleeding diathesis were excluded. According to size and shape of PDA, different types of devices were used such as detachable coils and Amplatzer duct occluders. Data was expressed as mean (SD) or median (minimum–maximum). Comparisons of means and medians were performed with Student’s t-test and with Mann–Whitney U test, respectively.

Results:

The median patient age and weight were 32 days and 1603 g (range 910–2000 g) respectively. Mean PDA diameter was 3.2±1.3 mm. Morphology of PDA was type A in 7 patients, type C in 10, type E in 1, and type B in 1 patient. There were no reported major complications. Stenosis of left pulmonary artery was detected in four patients, all of which resolved in 6 months follow-up.

Conclusion:

Percutaneous PDA closure in babies less than 2 kg is a safe and effective method that can be an alternative to surgery. Main distinguishing feature of this study is that it includes the largest cohort of patients less than 2 kg whose PDA closed percutaneously.