Clinically silent patent ductus arteriosus

Unveiling the Silent Ductus: A Classical Presentation of Patent Ductus Arteriosus in an Asymptomatic 23-Year-Old Male

The patent ductus arteriosus (PDA) refers to the persistence of a connection between the descending aorta distal to the left subclavian artery and the pulmonary trunk beyond fetal life. Adult congenital heart disease is a rare condition, with asymptomatic cases being particularly uncommon. The following report presents the case of a young adult male, aged 23, who was discovered to possess a patent ductus arteriosus in an incidental manner. The patient presented with an acute chest complaint and was found to be asymptomatic upon examination at the hospital. Based on the preliminary medical information provided, a tentative diagnosis of a ventricular septal defect was established. However, a comprehensive echocardiographic examination revealed the presence of a patent ductus arteriosus (PDA).

Patent ductus arteriosus in a late preterm neonate: think congenital hypopituitarism

A late preterm female neonate presented with initial respiratory distress and heart murmur attributed to a haemodynamically significant patent ductus arteriosus (hsPDA) not responding to two courses of ibuprofen. Thyroid function performed for prolonged neonatal jaundice at 3 weeks of life suggested central hypothyroidism. Subsequent adrenocorticotropic hormone stimulation test showing hypocortisolism and MRI revealing adenohypophysis hypoplasia confirmed the diagnosis of congenital hypopituitarism (CH). Commencement of hydrocortisone followed by thyroxine replacement coincided with clinical closure of the hsPDA within 72 hours of treatment. Hypothyroidism and hypocortisolism may have contributed to persistent hsPDA. Thyroid hormone increases cytochrome P450 activity, endothelin-1 and fibronectin expression. Hydrocortisone decreases sensitivity of ductus arteriosus to PGE2 These mechanisms have been postulated to cause ductal constriction and closure. Our case supports this association. hsPDA in a term and near-term neonate with a protracted disease course or associated midline defects should prompt the clinician to suspect CH (hypothyroidism and/or hypocortisolism).

Mouse models of patent ductus arteriosus (PDA) and their relevance for human PDA

The ductus arteriosus (DA) is a unique fetal vascular shunt, which allows blood to bypass the developing lungs in utero. After birth, changes in complex signaling pathways lead to constriction and permanent closure of the DA. The persistent patency of the DA (PDA) is a common disorder in preterm infants, yet the underlying causes of PDA are not fully defined. Although limits on the availability of human DA tissues prevent comprehensive studies on the mechanisms of DA function, mouse models have been developed that reveal critical pathways in DA regulation. Over 20 different transgenic models of PDA in mice have been described, with implications for human DA biology. Similarly, we enumerate 224 human single-gene syndromes that are associated with PDA, including a small subset that consistently feature PDA as a prominent phenotype. Comparison and functional analyses of these genes provide insight into DA development and identify key regulatory pathways that may serve as potential therapeutic targets for the management of PDA.

Adult congenital heart disease: a review of the simple lesions

There has been a dramatic improvement in mortality rates among children with congenital heart disease with advances in neonatal screening and surgical techniques, resulting in a significant increase in the prevalence of adults living with congenital heart disease. The most common simple lesions of congenital heart disease include atrial and ventricular septal defects, patent ductus arteriosus and coarctation of the aorta, which are typically detected and treated in childhood. However, they may also present in adulthood with non-specific symptoms or incidental findings, such as refractory hypertension. As the adult population of those living with congenital heart disease grows, it is imperative that all clinicians remain abreast of these common cardiac conditions, irrespective of their specialty, as patients may present with sequelae of their congenital heart disease or other non-cardiac conditions.

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.

Catheter Closure of Clinically Silent Patent Ductus Arteriosus Using the Amplatzer Duct Occluder II-Additional Size: A Single-Center Experience

Objectives

Transcatheter closure is the treatment of choice for most patent ductus arteriosus (PDA) in infants, children, and adults. However, there is a controversy regarding transcatheter closure of clinically silent PDAs. Some authors favor device closure to eliminate the lifelong risk of infective endarteritis while others recommend avoiding PDA closure in such patients. The study describes our experience of closing the silent PDAs using the Amplatzer duct occluder II-additional size (ADO II-AS) (St. Jude Medical Corp, St. Paul, MN).

Materials and methods

From April 2018 through March 2021, 52 consecutive pediatric patients aged 18 years and less with clinically silent PDA who had transcatheter closure at our center were enrolled. Patients were excluded if they had clinically detected PDAs; had surgical ligation of PDA with no residual shunt; had left heart dilatation on echocardiography; or moderate-sized PDAs closed with ADO II-AS. In addition, patients with an innocent murmur or murmur due to an associated lesion were included. This study was retrospective, and all of the 52 patients underwent PDA device closure using ADO II-AS.

Results

Fifty-two consecutive patients were enrolled with a median age of 17 months, range (97-2.5) 94.5 months. Mean weight was 11.29 kilogram, range (24.8-3.5) 21.3 kilogram, and mean follow-up was 13.5 months, range (29-0) 29 months. Thirty-one (59.6%) were females, and 21 (40.4%) were males. The mean procedure time was 30.6 min, range (60-10) 50 min, and mean fluoroscopic time was 5.5 min, range (28-1.7) 26.3 min. The mean volume of contrast given was 9.1 milliliter, range (30-4) 26 milliliter. Forty-five (45; 88.2%) patients had immediate closure of PDA. No patients had anesthetic or vascular complications; however, two patients had procedural complications. Device placement was unsuccessful in one patient with Downs syndrome. The mean follow-up for our patients was 13.5 months, range (29-0) 29 months; the patients were asymptomatic at the follow-up, and none of the patients had any residual leak. None of the patients showed coarctation or left pulmonary artery stenosis at the latest follow-up.

Conclusion

The usefulness of catheter-based therapy for silent PDA is less well-established by current evidence. Further studies are needed to justify the intervention solely based on the premise that the silent duct is a substrate for infective endarteritis; however, our reason to close silent PDA was to do so primarily because of social reasons. This study found that device closure of silent PDA is safe and effective using an ADO II-AS device with minimal risk of embolization and a low residual shunt rate. Coils have been used to close small PDAs, however, with higher rates of embolization and device malpositioning. We believe ADO-II AS offers an advantage of safety and efficacy over coils. In addition, the study highlights the advantage of using an ADO II-AS device, which can be delivered via a four French delivery system with no arterial complications.

Proteomics analysis of plasma protein changes in patent ductus arteriosus patients

Objective

Patent ductus arteriosus (PDA) is a congenital heart defect with an unclear etiology that occurs commonly among newborns. Adequately understanding the molecular pathogenesis of PDA can contribute to improved treatment and prevention. Plasma proteins may provide evidence to explore the molecular mechanisms of abnormal cardiac development.

Methods

Isobaric tags for relative and absolute quantitation (iTRAQ) proteomics technology was used to measure different plasma proteins in PDA patients (n = 4) and controls (n = 4). The candidate protein was validated by ELISA and Western blot (WB) assays in a larger sample. Validation of the location and expression of this protein was performed in mouse heart sections.

Results

There were three downregulated proteins and eight upregulated proteins identified in the iTRAQ proteomics data. Among these, protein disulfide-isomerase A6 (PDIA6) was further analyzed for validation. The plasma PDIA6 concentrations (3.2 ± 0.7 ng/ml) in PDA patients were significantly lower than those in normal controls (5.8 ± 1.2 ng/ml). In addition, a WB assay also supported these results. PDIA6 was widely expressed in mouse heart outflow tract on embryonic day 14.5.

Conclusion

Plasma proteomics profiles suggested novel candidate molecular markers for PDA. The findings may allow development of a new strategy to investigate the mechanism and etiology of PDA.

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.

Transcatheter closure of residual patent ductus arteriosus

INTRODUCTION

Residual patent ductus arteriosus (rPDAs) can occur following surgical or transcatheter treatment, and are indicated for closure because of the risks of infective endarteritis and hemolysis in addition to the hemodynamic effect of the residual left-to-right shunt.

METHODS

This retrospective descriptive study describes our experience at two Egyptian centers (Cairo University Children's Hospital & Tanta University Hospital) with transcatheter treatment of rPDAs, from January 2009 to October 2017.

RESULTS

Twenty cases were treated: 17/20 postsurgical and 3/20 post-transcatheter, at a mean period of 13.4 ± 9.3 months from the initial procedure. The median rPDA size was 2 mm (range2-3.5 mm). Most common ductal anatomy was the conical shape. All rPDAs were successfully closed with either coils (13/20) or devices (6/20), except one case where the residual flow was within the device mesh material. Coils could be deployed from the antegrade or the retrograde approaches although the latter was associated with a higher incidence of late shunt occlusion. One case with a malpositioned device required simultaneous device and LPA stent deployment.

CONCLUSION

Transcatheter closure of rPDAs is feasible in most cases, but may be technically challenging.

Transcriptional profiling of the ductus arteriosus: Comparison of rodent microarrays and human RNA sequencing

DA closure is crucial for the transition from fetal to neonatal life. This closure is supported by changes to the DA's signaling and structural properties that distinguish it from neighboring vessels. Examining transcriptional differences between these vessels is key to identifying genes or pathways responsible for DA closure. Several microarray studies have explored the DA transcriptome in animal models but varied experimental designs have led to conflicting results. Thorough transcriptomic analysis of the human DA has yet to be performed. A clear picture of the DA transcriptome is key to guiding future research endeavors, both to allow more targeted treatments in the clinical setting, and to understand the basic biology of DA function. In this review, we use a cross-species cross-platform analysis to consider all available published rodent microarray data and novel human RNAseq data in order to provide high priority candidate genes for consideration in future DA studies.

A rare case of acyanotic congenital heart disease, large patent ductus arteriosus with pre-ductal coarctation of descending thoracic aorta with patent ductus arteriosus closure and extra anatomical bypass grafting

We report a case of 18-year-old female patient with large patent ductus arteriosus (PDA)-preductal coarctation of descending thoracic aorta. She underwent large PDA closure with a prosthetic graft from ascending aorta to descending thoracic aorta by mid-sternotomy on cardiopulmonary bypass machine under total hypothermic circulatory arrest.

Minimally Invasive Patent Ductus Arteriosus Ligation

A patent ductus arteriosus is a common condition, particularly in premature infants. Many spontaneously resolve but those that lead to clinical instability require closure. Conservative measures can be highly successful in selected groups. Surgical repair is effective and both open and minimally invasive approaches can be used. The minimally invasive approach may result in less long-term morbidity from a thoracotomy and may prove advantageous for these fragile infants, including less pain, shorter time on the ventilator, and shorter hospital stays.

Multicenter Off-Label Use of Nit-Occlud Coil in Retrograde Closure of Small Patent Ductus Arteriosus

We studied the safety and efficacy of closing patent ductus arteriosus by Nit-Occlud coils via retrograde approach. This is a retrospective study of 46 attempts to close ducts by this method in two hospitals in Egypt and Iran. Ductus arteriosus was crossed by left or right Judkins or endhole catheters. The coil was delivered via the same catheter or the provided endhole catheter after exchange. The procedure was successful in 42 out of 46 attempts. Fluoroscopy and procedural times were significantly shorter when the catheter was not exchanged. This method is effective and safe for the closure of small ducts. Crossing the duct and delivering the coil by a left Judkins catheter is the easiest and fastest way to perform this method.

Is spontaneous closure of a patent arterial duct common?

As closing a patent arterial duct is relatively simple, safe, and successful, most children with a patent arterial duct have it closed soon after diagnosis. The larger ducts are closed to prevent congestive heart failure, pulmonary vascular disease, or aneurysmal dilatation of the ductus, and smaller ducts are closed to prevent infective endocarditis. Consequently, there is no opportunity to determine whether spontaneous closure or diminution in size of the patent arterial duct is common. If the duct does become smaller, flow through it may be so low that no murmur is produced - the silent ductus. The frequency and best management of the silent patent arterial duct are unknown, and we do not know whether these tiny ducts are the last stage before spontaneous closure.

Transient severe left ventricular dysfunction following percutaneous patent ductus arteriosus closure in an adult with bicuspid aortic valve: A case report

The present study reported the case of a 60-year-old female with patent ductus arteriosus (PDA) and a bicuspid aortic valve, who presented with transient severe left ventricular (LV) dysfunction following percutaneous closure of PDA, as identified by speckle tracking analysis. Transient LV dysfunction following PDA closure has previously been reported; however, severe LV dysfunction is rare. In the present case, the combination of a large PDA size, large amount of shunting, LV remodeling and bicuspid aortic valve may have induced serious deterioration of LV function following PDA closure. Furthermore, speckle-tracking echocardiography may be useful in the estimation of functional alterations in the myocardium of the LV following PDA closure. The observations detailed in the present study may improve the understanding of the pathophysiology and myocardial patterns of transient left ventricular dysfunction following PDA closure in adult humans.

The various hemodynamic profiles of the patent ductus arteriosus in adults

The patent ductus arteriosus (PDA) has diverse clinical and hemodynamic manifestations depending on its size and the degree of the ensuing left-to-right shunt. A small PDA that causes minor shunting has no major hemodynamic consequences. Conversely, a large PDA with a significant left-to-right shunt may lead to various hemodynamic abnormalities. These include left-sided volume overload that may result in heart failure and/or pulmonary hypertension, the latter being a flow-dependent and mostly reversible phenomenon. The most feared complication is the development of severe and irreversible pulmonary hypertension (Eisenmenger physiology). In this manuscript, we provide examples of the various hemodynamic profiles of PDA as assessed by echocardiography in the adult population.

Co-existence of patent ductus arteriosus and left brachiocephalic artery: a case report

Patent ductus arteriosus (PDA) may exist with other cardiovascular anomalies, which must be considered at the time of diagnosis. We report a rare co-existence of PDA and a variant of aortic arch branching pattern in a 12-year old Tanzanian female patient during surgery to close a PDA. In this case, the ‘left brachiocephalic trunk’ was seen to arise from the arch of aorta distal to the origin of the right brachiocephalic trunk. We discuss the relevant literature, its potential embryologic development and clinical significance.

Comparative study between real time three dimensional echocardiogram and angiography in evaluation of patent ductus arteriosus, single center experience

In this study we compared the real time three dimensional echocardiogram data in evaluation of patent ductus arteriosus with the gold standard angiography.

METHODS

This study included 25 patients with PDA referred to Tanta University Hospital for elective cardiac catheterization. The patients comprised seven males and 18 females, with a mean age of 3.7 ± 0.36 years. The study duration was six months. All patients underwent full 2D echocardiogram as well as real time three-dimensional echocardiogram (RT3DE). Essential measurements included the pulmonary end of the duct, duct length, aortic end and aortic ampulla as well as the anatomical type of the PDA. Data obtained by RT3DE were compared against 2D echocardiogram and angiography.

RESULTS

There was no significant difference between 3D echocardiogram and angiography (P = 0.001) in the pulmonary end of the duct measurement. Neither were there any significant differences between the length of the duct or the aortic end measured by 3D echocardiogram and by angiography (P = 0.001 in both). While there was adequate agreement between both 2D and 3D echocardiogram and angiography in determining the anatomical type of the PDA, 3D echocardiogram determined type A and type E ductus more accurately than 2D echocardiogram. The feasibility of Q lab analysis of PDA was 96%, while the feasibility of gated color flow 3D acquisitions in determining anatomical types was 64%.

CONCLUSION

There was complete agreement on location, size, morphology and surrounding structure of PDA between 2D and 3D echocardiogram, and angiography. This result illustrates the need for the proper placement of the device in catheterization laboratories.

Congenital heart malformations induced by hemodynamic altering surgical interventions

Embryonic heart formation results from a dynamic interplay between genetic and environmental factors. Blood flow during early embryonic stages plays a critical role in heart development, as interactions between flow and cardiac tissues generate biomechanical forces that modulate cardiac growth and remodeling. Normal hemodynamic conditions are essential for proper cardiac development, while altered blood flow induced by surgical manipulations in animal models result in heart defects similar to those seen in humans with congenital heart disease. This review compares the altered hemodynamics, changes in tissue properties, and cardiac defects reported after common surgical interventions that alter hemodynamics in the early chick embryo, and shows that interventions produce a wide spectrum of cardiac defects. Vitelline vein ligation and left atrial ligation decrease blood pressure and flow; and outflow tract banding increases blood pressure and flow velocities. These three surgical interventions result in many of the same cardiac defects, which indicate that the altered hemodynamics interfere with common looping, septation and valve formation processes that occur after intervention and that shape the four-chambered heart. While many similar defects develop after the interventions, the varying degrees of hemodynamic load alteration among the three interventions also result in varying incidence and severity of cardiac defects, indicating that the hemodynamic modulation of cardiac developmental processes is strongly dependent on hemodynamic load.

Promotion of artery occlusion in dogs by percutaneous rotational atherectomy

BACKGROUND

This study aims to offer experimental data and indirect evidences for the application of percutaneous rotational atherectomy to treat patent ductus arteriosus (PDA).

METHODS

Eleven dogs (6 male dogs and 5 female dogs; aged 14-20 months, with an average of 16.7±3.2 months; weight 20-25 kg, with an average of 22.7±2.5 kg) were enrolled in this study. The diameters of the left and right arteries ranged from 3.2 to 4.8 mm (average 3.9±0.6 mm) on percutaneous angiography. Percutaneous rotational atherectomy with proper rotablator (the size was 1-1.5 mm larger than the artery diameter) was performed in the arterial intima. After 4 weeks from percutaneous rotational atherectomy, arteriography was conducted to observe the changes in artery diameter. Then all dogs were sacrificed and the pathologic examination was conducted on the left and right axillary arteries.

RESULTS

There were obvious changes with different degrees in 22 arteries, including 8 arteries with complete occlusion and 12 arteries with stenosis (≥2/3, 1/2, and 1/3 stenosis in 4, 4, and 4 arteries, respectively). The occlusion rate was 36.4% and the total effective rate was 90.9%. It was considered failure in other 2 arteries with <1/3 of stenosis.

CONCLUSIONS

Percutaneous rotational atherectomy of arterial intima can promote the occlusion of arteries. This has provided a new choice for the treatment of PDA.

Transcatheter closure of patent ductus arteriosus: past, present and future

This review aims to describe the past history, present techniques and future directions in transcatheter treatment of patent ductus arteriosus (PDA). Transcatheter PDA closure is the standard of care in most cases and PDA closure is indicated in any patient with signs of left ventricular volume overload due to a ductus. In cases of left-to-right PDA with severe pulmonary arterial hypertension, closure may be performed under specific conditions. The management of clinically silent or very tiny PDAs remains highly controversial. Techniques have evolved and the transcatheter approach to PDA closure is now feasible and safe with current devices. Coils and the Amplatzer Duct Occluder are used most frequently for PDA closure worldwide, with a high occlusion rate and few complications. Transcatheter PDA closure in preterm or low-bodyweight infants remains a highly challenging procedure and further device and catheter design development is indicated before transcatheter closure is the treatment of choice in this delicate patient population. The evolution of transcatheter PDA closure from just 40 years ago with 18F sheaths to device delivery via a 3F sheath is remarkable and it is anticipated that further improvements will result in better safety and efficacy of transcatheter PDA closure techniques.

Transcatheter closure of patent ductus arteriosus

More than three decades have passed since the introduction of transcatheter devices for closure of patent ductus arteriosus, and many occluders have been made available since then. The ideal requirements of any procedure are a user-friendly technique, optimum success rate, no residual anomaly, minimal morbidity/mortality, and comparability or superiority to the existing conventional modality of treatment. With various advancements in device design, delivery and assisted systems, the tremendous procedural safety and effectiveness, along with low cost and widespread availability of these devices makes transcatheter closure of patent ductus arteriosus a preferred therapeutic modality in all age groups, with decreasing demographic trends of surgical management.

The patent ductus arteriosus in term infants, children, and adults

During fetal life, the ductus arteriosus is a normal and essential structure that connects the pulmonary artery to the distal aortic arch, permitting right ventricular ejection into the aorta. After birth, with commencement of pulmonary blood flow and a 2-ventricle circulation, a variety of physiological and biochemical signals normally result in complete closure of the ductus. Persistent patency of the ductus arteriosus may impair systemic cardiac output and result in deleterious effects on the cardiovascular system and lungs. Although surgery is still the treatment of choice for most premature infants with patent ductus arteriosus (PDA), transcatheter techniques have largely supplanted surgery for closure of PDA in children and adults. This article is a review of the PDA in term infants, children, and adults, with focus on the clinical manifestations and management.

Transcatheter closure of a residual patent ductus arteriosus after surgical ligation in children

BACKGROUND AND OBJECTIVES

To assess the safety and efficacy of transcatheter closure of residual ductal flow after initial surgical ligation of the arterial duct.

SUBJECTS AND METHODS

Between June 2005 and December 2009, transcatheter occlusion of residual postsurgical ductus arteriosus was performed in six children.

RESULTS

The mean patient age was 10±5.5 years; mean post-procedural time since the initial surgical closure was 6.3±4.5 years. The mean diameter of the patent ductus arteriosus on angiography was 1.3±0.5 mm (range, 0.8 to 2.4 mm). Three different types of coils were used successfully without any complications.

CONCLUSION

Transcatheter occlusion of residual postsurgical arterial duct is a safe and successful procedure. However, attention should be paid due to the distorting shape of the arterial duct.

To close or not to close: the very small patent ductus arteriosus

Patent ductus arteriosus (PDA) accounts for approximately 10% of all congenital heart diseases, with an incidence of at least 2-4 per 1000 term births. Closure of the large, hemodynamically significant PDA is established as the standard of care, and can be performed safely and effectively using either surgical or transcatheter methods. The appropriate management of the very small, hemodynamically insignificant PDA is less clear. Routine closure of such defects has been advocated to eliminate or reduce the risk of infective endocarditis (IE). However, the risk of IE in patients with a small PDA appears to be extremely low, and IE is treatable. Although closure of the small PDA is generally safe and technically successful, it is unknown whether this treatment truly improves the risk:benefit balance compared with observation. In this article, we review the published literature on the natural history and treatment outcomes in individuals with a PDA, the epidemiology and outcomes of IE, particularly in association with PDA, and the rationale and evidence for closure of the very small PDA.

Feasibility and safety of transcatheter intervention for complex patent ductus arteriosus

We evaluated the transcatheter intervention of complex patent ductus arteriosus (PDA) in Chinese adults. Between January 2004 and April 2008, 112 adult patients (43 males, 69 females, mean age 31 +/- 19 years) underwent intervention. Coils were used for patients with small PDA, and Amplatzer duct occluders or China-made mushroom-shaped occluders were used for patients with moderate-to-large PDA. The success rate of transcatheter intervention was 93.8%, and 9 patients (8.0%) had small residual shunts. At the end of 12 months follow-up, the rate of residual shunts was 1.8%. Peak systolic pulmonary pressure decreased from 94 +/- 21 mm Hg preintervention to 58 +/- 20 mm Hg postintervention (P < .001). No severe procedure-related complications (including death, dislocation of occluders, stenosis of aorta or pulmonary artery) occurred. Some patients developed hemolysis or vascular access complications, all resolved by conservative therapy. Transcatheter intervention is an effective and safe treatment for adult PDA patients with complex anatomic or hemodynamic conditions.

Evolution of strategies for management of the patent arterial duct

Persistent patency of the arterial duct represents one of the most common lesions in the field of congenital cardiac disease. The strategies for management continue to evolve. In this review, we focus on management beyond the neonatal period. We review the temporal evolution of strategies for management, illustrate the currently available the techniques for permanent closure of the patent arterial duct, review the expected outcomes after closure, discuss the current controversy over the appropriate treatment of the so-called "silent" duct, and provide recommendations for the current state of management of patients with persistent patency of the arterial duct outside of the neonatal period.At the Congenital Heart Institute of Florida, we now recommend closure of all patent arterial ducts, regardless of their size. Before selecting and performing the type of procedure, we explain the natural history of the persistently patent arterial duct to the parents or legal guardian of the child. Particular emphasis is placed on the risks of endocarditis, including the recognition that many cases of endocarditis may not be preventable. The devastating effects of endocarditis, coupled with the perception of more anecdotal reports of endocarditis with the silent duct, as well as the low risk of interventions, has led us to recommend closure of the patent arterial duct in these situations. We now recommend intervention, after informed consent, for all patients with a patent arterial duct regardless of size, including those in which the patent duct is "silent". We recognize, however, that this remains a controversial topic, especially given the new recommendations for endocarditis prophylaxis from American Heart Association. Since 2003, our strategy for closure of the patent arterial duct has changed subsequent to the availability of the Amplatzer occluder. This new device has allowed significantly larger patent arterial ducts to be closed with interventional catheterization procedures that in the past would have been closed at surgery. During the interval between 2002 and 2006 inclusive, the overall surgical volume at our Institute has been stable. Over this period, the number of patients undergoing surgical ligation of the patent arterial duct has decreased, with this decline in volume most notable for the subgroup of patients weighing more than five kilograms. This decrease has been especially notable in thoracoscopic procedures and is attributable to the increased ability to close larger ducts using the Amplatzer occluder. For infants with symptomatic pulmonary overcirculation weighing less than 5 kilograms, our preference is for the surgical approach. For patients who have ductal calcification, significant pleural scarring, or "window-like" arterial ducts, video-assisted ligation is not an option and open surgical techniques are used. When video-assisted ligation is possible, the approach is based on family and surgeon preference. When open thoracotomy is selected, we usually use a muscle-sparing left posterolateral thoracotomy. For patients weighing more than 5 kilograms, we currently recommend percutaneous closure for all patent arterial ducts as the first intervention, reserving surgical treatment for those cases that are not amenable to the percutaneous approach. For symptomatic infants weighing greater than 5 kilogram with large ducts, we prefer to use the Amplatzer occluder. In rare instances, the size of the required ductal occluder is so large that either encroachment into the aorta or pulmonary arteries is noted, and the device is removed. The child is then referred for surgical closure. We can now often predict via echocardiography that a duct is too large for transcatheter closure, even with the Amplatzer occluder, and refer these patients directly to surgery. For patients with an asymptomatic patent arterial duct, we prefer to wait until the weight is from 10 to 12 kilograms, or they are closer to 2 years of age. If the patent arterial duct is greater than 2.0 to 2.5 millimetres in diameter, our preference is to use the Amplatzer occluder. For smaller ducts, we typically use stainless steel coils. Using this strategy, we close all patent arterial ducts, regardless of their size.

Pulmonary endarteritis and subsequent pulmonary embolism associated with clinically silent patent ductus arteriosus

A 49-year-old man without heart murmur was admitted with fever because of bacteremia following a tooth extraction. Antibiotics rapidly alleviated the fever; however, a small nodule in the pulmonary artery was identified on computed tomography (CT). When the patient experienced chest discomfort with fever, CT demonstrated the absence of the nodule and the appearance of an abnormal lung opacity, and echocardiography showed turbulent retrograde flow in the pulmonary artery. We had the rare opportunity to follow a case of pulmonary bacterial endarteritis and subsequent pulmonary embolism with clinically silent patent ductus arteriosus (PDA) that was confirmed by 3-dimensional CT.

Prevalence of congenital heart disease

BACKGROUND

Today most patients with congenital heart disease survive childhood to be cared for by adult cardiologists. The number of physicians that should be trained to manage these lesions is unknown because we do not know the number of patients.

METHODS

To answer this question, the expected numbers of infants with each major type of congenital heart defect born in each 5-year period since 1940 were estimated from birth rates and incidence. The numbers expected to survive with or without treatment were estimated from data on natural history and the results of treatment. Finally, lesions were categorized as simple, moderate, or complex, based on the amount of expertise in management needed for optimal patient care.

RESULTS

From 1940 to 2002, about 1 million patients with simple lesions, and half that number each with moderate and complex lesions, were born in the United States. If all were treated, there would be 750,000 survivors with simple lesions, 400,000 with moderate lesions, and 180,000 with complex lesions; in addition, there would be 3,000,000 subjects alive with bicuspid aortic valves. Without treatment, the survival in each group would be 400,000, 220,000, and 30,000, respectively. The actual numbers surviving will be between these 2 sets of estimates.

CONCLUSIONS

Survival of patients with congenital heart disease, treated or untreated, is expected to produce large numbers of adults with congenital disease, and it is likely that many more adult cardiologists will need to be trained to manage moderate and complex congenital lesions.

Interventional treatment of patent ductus arteriosus in 2004

In 2004, the interventional treatment of patent ductus arteriosus (PDA) is definitive and curative. In current practice, coils are used for smaller PDA, and devices are employed for larger PDA. Developing technologies offer small improvements in control and results, but do not appear to promise major changes in practice. This review summarizes the current and emerging interventional technologies directed at PDA closures.

The incidence of congenital heart disease

This study was designed to determine the reasons for the variability of the incidence of congenital heart disease (CHD), estimate its true value and provide data about the incidence of specific major forms of CHD. The incidence of CHD in different studies varies from about 4/1,000 to 50/1,000 live births. The relative frequency of different major forms of CHD also differs greatly from study to study. In addition, another 20/1,000 live births have bicuspid aortic valves, isolated anomalous lobar pulmonary veins or a silent patent ductus arteriosus. The incidences reported in 62 studies published after 1955 were examined. Attention was paid to the ways in which the studies were conducted, with special reference to the increased use of echocardiography in the neonatal nursery. The total incidence of CHD was related to the relative frequency of ventricular septal defects (VSDs), the most common type of CHD. The incidences of individual major forms of CHD were determined from 44 studies. The incidence of CHD depends primarily on the number of small VSDs included in the series, and this number in turn depends upon how early the diagnosis is made. If major forms of CHD are stratified into trivial, moderate and severe categories, the variation in incidence depends mainly on the number of trivial lesions included. The incidence of moderate and severe forms of CHD is about 6/1,000 live births (19/1,000 live births if the potentially serious bicuspid aortic valve is included), and of all forms increases to 75/1,000 live births if tiny muscular VSDs present at birth and other trivial lesions are included. Given the causes of variation, there is no evidence for differences in incidence in different countries or times.

Five-loop coil occlusion of patent ductus arteriosus prevents recurrence of shunt at follow-up

Recent reports suggest reopening of the patent ductus arteriosus (PDA) after complete occlusion with three-loop Gianturco coils. We hypothesize that five-loop coils may produce a larger thrombus than three-loop coils, which will result in no or less probability of recanalization of PDA during follow-up. This study is designed to test this hypothesis. Follow-up echocardiographic and Doppler data of 30 patients who underwent five-loop coil occlusion of small to medium-sized PDA during a 33-month period ending December 1998 were examined. Thirty patients had no residual shunt on echo Doppler study on the day following the procedure and were followed for 6 to 30 months (median, 12) after coil implantation. At the last follow-up study, none of the patients had a residual shunt and left atrial size decreased. Careful pulsed, continuous wave, and color Doppler interrogation of left/main pulmonary artery junction and proximal descending aorta did not reveal any evidence for obstruction. The follow-up data suggest that complete occlusion of small- to medium-sized PDAs is feasible with five-loop coils without evidence for recanalization at a mean follow-up of 12 months. Much longer (2 to 5 years) follow-up data may be necessary to confirm these observations. We speculate that a greater degree of thrombosis is produced within the ductus by the five-loop coils, which in turn may be responsible for lack of shunt recurrence. We recommend use of five-loop instead of three-loop coils for transcatheter occlusion of small- to medium-sized PDAs.

Endothelialization of the coils used to occlude a persistent ductus arteriosus: an angiographic study

To assess the endothelialization of the coils used to close a persistent ductus arteriosus (PDA), the present study comprised a review of the follow-up aortograms and pulmonary angiograms in 25 patients who underwent coil occlusion. The minimal diameter and the length of the PDA were measured prior to the procedure, and the shortest distance between the aortic end of the deployed coil and the aortic end of the PDA was measured after coil deployment. Evidence of endothelial coverage of the coil was sought on follow-up angiograms performed 6-24 (15+/-5) months later and the factors that determined the thickness of the endothelial coverage on the aortic end were investigated. Separation of the coil and the contrast column were detected at the aortic end in all cases and at the pulmonary end in 18 of 25 cases. The thickness of the separation ranged from 0.4 to 1.3 (0.7+/-0.2) mm at the aortic end and 0.3 to 0.8 (0.6+/-0.2) mm at the pulmonary end. The length of the ductus and of the ampulla had a significant positive correlation with the thickness of the aortic end separation. Apparent endothelial coverage of the coil was completed by 6 months after coil occlusion. Infective endocarditis or thromboembolism is an unlikely complication once endothelium covers the implanted coil.

Coil occlusion of the patent ductus arteriosus: lessons learned

PURPOSE

To review the clinical outcomes of catheter-directed coil occlusion (coil occlusion) of persistently patent ductus arteriosus (PDA) at a pediatric tertiary care hospital.

METHODS

A retrospective review of all patients referred to the Cardiac Catheterization Laboratory for coil occlusion at our institution was performed. Twenty-one consecutive patients (12 female) underwent coil occlusion and follow-up between May 1995 and December 1997. We undertook PDA occlusion if: (a) the PDA narrowed to less than 4 mm on echocardiogram and (b) the minimum body weight was approximately 10 kg. Standard right and retrograde left heart catheterization was performed, followed by coil occlusion. Color-flow mapping (CFM) was used intra-procedurally to confirm occlusion of the PDA with a follow-up study several weeks later.

RESULTS

The median age and weight of the patients were 33 months and 13.2 kg, respectively. Fourteen patients received one coil, with six requiring a second coil and one requiring multiple coils. Initial follow-up was at a median of 2.4 months. At latest follow-up, 2 patients still have persistent flow at the ductal level. The coils were deployed without complication or embolization.

CONCLUSIONS

A review of our first 21 cases demonstrated three important lessons: (1) the maximum diameter of the PDA suitable for coil occlusion is approximately 3 mm; (2) CFM must show complete obliteration of flow in the catheterization lab in order to ensure occlusion of the PDA at follow-up; and (3) the Jackson detachable system allows for precise placement of the coil, often within another coil.

Follow-up results of transvenous occlusion of patent ductus arteriosus with the buttoned device

OBJECTIVES

The purpose of this presentation is to document results of buttoned device (BD) occlusion of patent ductus arteriosus (PDA) in a large number of patients with particular emphasis on long-term follow-up in an attempt to provide evidence for feasibility, safety and effectiveness of this method of PDA closure.

BACKGROUND

Immediate and short-term results of BD occlusion of PDA have been documented in a limited number of children.

METHODS

During a six-year period ending August 1996, transcatheter BD closure of PDA was attempted in 284 patients, ages 0.3 to 92 years (median 7) under a protocol approved by the local institutional review boards and FDA with an investigational device exemption in U.S. cases.

RESULTS

The PDAs measured 1 to 15 mm (median 4) at the narrowest diameter; 20 were larger than 8 mm and 10 larger than 10 mm. They were occluded with devices measuring from 15 to 35 mm delivered via 7F (N = 140) or 8F (N = 144) sheaths. Successful implantation of the device was accomplished in 278 (98%) of 284 patients. The Qp:Qs decreased from 1.8+/-0.6 (mean+/-SD) to 1.09+/-0.19 (p < 0.001). Effective occlusion defined as no (N = 167 [60%]) or trivial (N = 79 [28%]) residual shunt was achieved in 246 (88%) patients. All types of PDAs, irrespective of the shape (conical, tubular or short), size (small or large) or length (short or long) of the PDA and previously implanted Rashkind devices, could be occluded. Follow-up data, 1 to 60 months (median 24) after device implantation, were available in 234 (84%) patients. Seven (3%) patients required reintervention to treat residual shunt with (N = 2) or without (N = 5) hemolysis. Actuarial reintervention-free rates were 95% at 1 and 5 years. There was gradual reduction of actuarial residual shunts and were 40%, 28%, 21%, 14%, 11%, 10%, 6% and 0% respectively at 1 day, 1, 6, 12, 24, 36, 48 and 60 months after device implantation. Incorporation of folding plug over the button loop in 10 additional patients produced immediate and complete occlusion of PDA.

CONCLUSIONS

This large multiinstitutional experience confirms the feasibility, safety and effectiveness of buttoned device closure of PDAs. All types of PDAs irrespective of the shape, length and diameter can be effectively occluded. Incorporation of folding plug over the button loop produces complete PDA occlusion at the time of device implantation.

Effectiveness of five-loop coils to occlude patent ductus arteriosus

Coil occlusion of patent ductus arteriosus with 5-loop coils was undertaken in 10 patients without coil embolizations, and with 90% immediate occlusion and 100% occlusion at follow-up. We conclude that 5-loop coil occlusion of patent ductus arteriosus is safe and effective.

Coil occlusion versus conventional surgical closure of patent ductus arteriosus

This retrospective cohort study evaluated the clinical outcome and cost-effectiveness of 2 treatment strategies for children with an isolated restrictive patent ductus arteriosus. Results indicate a superior cost-effectiveness of transcatheter coil occlusion compared with conventional surgery for these patients.

Cost and efficacy of surgical ligation versus transcatheter coil occlusion of patent ductus arteriosus

OBJECTIVE

The purpose of this study was to compare cost and efficacy of surgical closure of patent ductus arteriosus using new critical pathway methods with outpatient transcatheter coil occlusion of patent ductus arteriosus.

METHODS

Surgical techniques included a transaxillary, muscle-sparing thoracotomy, triple ligation of the patent ductus arteriosus, no chest tube, and discharge from the hospital within 24 hours. Transcatheter coil occlusion of patent ductus arteriosus was done as an outpatient procedure. Costs were compared with inclusion of all hospital and professional charges.

RESULTS

From July 1994 until March 1996, 20 patients underwent coil occlusion of patent ductus arteriosus and 20 patients underwent surgical closure of patent ductus arteriosus. Duration of hospitalization was significantly less for the patients receiving coil occlusion (11 +/- 6 hours) as compared with that for the patients having surgical ligation (28 +/- 7 hours, p < 0.05). Total charges were similar for surgical ligation ($7101 +/- $408) as compared with those for coil occlusion ($7104 +/- $886, p > 0.05). Morbidity in coil occlusion included inability to occlude the patent ductus arteriosus in two patients (2/20, 10%) and residual patency in two patients (2/18, 11%). Morbidity in the surgical group included nausea and vomiting necessitating hospitalization for more than 36 hours in one patient (1/20, 5%), transient left recurrent laryngeal nerve palsy in one (1/20, 5%), and pneumothorax in two patients (2/20, 10%). There were no instances of residual patency in the surgical group.

CONCLUSIONS

Transaxillary thoracotomy without tube thoracostomy and with critical pathway methods allows safe and effective ligation of a patent ductus arteriosus with early hospital discharge. This surgical method has similar cost, higher efficacy rate, and applicability in all patients as compared with newer transcatheter coil occlusion techniques for closure of a patent ductus arteriosus.

Transcatheter occlusion of patent ductus arteriosus: which method to use and which ductus to close

Many devices have been developed for transcatheter occlusion of PDA. Bulkiness of the device, complexity of the procedure, and significant residual complications make the majority of the devices unsuitable for routine clinical use. Although no randomized comparative clinical trials exist, on the basis of published literature and my personal experience, coil occlusion may be best suited to close small ducts (< or = 3.5 mm) and the adjustable buttoned device may be most appropriate for large PDAs (> 3.5 mm). Clinical trials on larger patient populations than are currently available and long-term follow-up are necessary to further support these recommendations. Indications for transcatheter closure should be exactly as those used for surgical closure: PDA with audible continuous murmur with echo Doppler confirmation. The so-called silent ducts need not be closed.

Follow-up of coil occlusion of patent ductus arteriosus

OBJECTIVE

We sought to determine the prevalence and fate of residual ductal shunting following coil occlusion of patent ductus arteriosus.

BACKGROUND

Although transcatheter coil occlusion of patent ductus arteriosus has gained popularity, few follow-up data have been reported.

METHODS

A review of 75 patients who underwent coil occlusion was performed. Residual shunting was investigated by Doppler echocardiography in follow-up. Angiograms were reviewed to obtain minimal ductal diameter and ductal angiographic type.

RESULTS

Residual shunts were found in 31 patients (41%) on the day of the procedure, and of these, spontaneous closure was noted in 17 (55%) at 2 weeks to 20 months of follow-up. Of the 75 patients studied, 5 (7%) required a second coil procedure, and 10 (13%) remained with persistent residual shunts at most recent follow-up. Actuarial analysis estimated a 6 +/- 5% prevalence of residual shunts 20 months after a single coil procedure and 3 +/- 3% after all coil procedures. Minimal ductal diameter was associated with immediate complete ductal occlusion by a single coil. These patients had significantly smaller (p = 0.003) minimal ductal diameters (1.2 +/- 0.7 mm) than those who required two coils during their initial procedure to achieve immediate occlusion (1.9 +/- 0.7 mm), those who required a second coil procedure (2.0 +/- 0.9 mm), those who had spontaneous closure of residual shunts (1.9 +/- 0.7 mm) and those with persistent residual shunts (2.0 +/- 0.9 mm). No association was identified between ductal angiographic type and outcome of coil occlusion. No late adverse clinical events of coil occlusion or evidence of recanalization was found.

CONCLUSIONS

Small residual shunts are common after coil embolization of patent ductus arteriosus, but most close spontaneously. Actuarial analysis estimates complete closure in 94% at 20 months, and reintervention was required in only 7% of patients.