Stent implantation for coarctation of the aorta in children <30 kg

Procedural Characteristics and Outcomes of Transcatheter Interventions for Aortic Coarctation: A Report From the IMPACT Registry

Background

Although surgical repair was the traditional first-line treatment for native coarctation of the aorta (CoA), balloon angioplasty (BA) and stenting are now increasingly being performed. We aimed to determine the practice patterns and acute outcomes of transcatheter interventions for native coarctation in the largest multicenter registry for congenital catheterization.

Methods

CoA interventions from the IMPACT (IMproving Pediatric and Adult Congenital Treatment) National Cardiovascular Data Registry were analyzed. The procedure choice and acute outcomes were compared among patients with no prior interventions on the aortic isthmus (native CoA). Procedural success was defined as no major adverse events (MAEs) and a final peak gradient of <20 mm Hg and optimal outcome as no MAEs and a final gradient of <10 mm Hg.

Results

Over the 8-year study period, 5928 CoA procedures were performed, of which 1187 were performed in patients with native CoA. In this group, stenting was performed in more then half of children aged >1 year and >90% of those aged >8 years. Procedural success was achieved in >90% of stenting procedures but in only 69% of BAs. Stent implantation was associated with a higher likelihood of optimal gradient (<10 mm Hg) after adjustment for age and baseline characteristics. MAEs were most common in children aged <1 year (14%), occurred in 2% to 2.5% of those aged 1 to 18 years and in 6.6% of adults (P < .001), and were more likely after BA than after stenting (odds ratio, 0.5; 95% CI, 0.28-0.9; unadjusted P = .02).

Conclusions

Catheter interventions for native coarctation are performed safely in older children and adults, with a high degree of immediate procedural success, particularly with stenting.

An Up-to-Date Narrative Review on Congenital Heart Disease Percutaneous Treatment in Children Using Contemporary Devices

Background: Congenital heart pathology has a significant burden regarding morbidity and mortality in the pediatric population. Several transcatheter interventions and devices have been designed as an alternative to surgical repair. Percutaneous interventions have been proven to yield good results in most cases but with less stress and trauma than that attributed to surgical treatment, especially in frail pediatric patients. We aimed to review the literature and to investigate the feasibility and efficacy of transcatheter interventions and implantable devices for congenital heart disease management in children. Methods: We performed a search in Scopus and MEDLINE databases using prespecified keywords to retrieve clinical studies published between 2000 and 2021. Results: This article provides an up-to-date review regarding the applicability of interventional techniques in simple inter-atrial or inter-ventricular defects, and in challenging congenital defects, such as hypoplastic left heart syndrome, tetralogy of Fallot, or coronary artery fistula. Furthermore, we reviewed recent indications for defibrillator and cardiac resynchronization therapy, and new and promising devices currently being tested. Conclusion: Transcatheter treatment represents a feasible and efficient alternative to surgical repair of congenital heart defects. Novel devices could extend the indications and possibilities of percutaneous interventions in pediatric patients with congenital heart diseases.

Zn-Mg-WC Nanocomposites for Bioresorbable Cardiovascular Stents: Microstructure, Mechanical Properties, Fatigue, Shelf Life, and Corrosion

Zinc (Zn) and Zn alloys have been studied as potential materials for bioresorbable stents (BRSs) in the last decade due to their favorable biodegradability and biocompatibility. However, most Zn alloys lack the necessary combination of strength, ductility, fatigue resistance, corrosion rate (CR), and thermal stability needed for such applications. In this study, nanoparticles made of tungsten carbide (WC) were successfully incorporated into Zn alloyed with 0.5 wt % magnesium (Mg) and evaluated for their suitability for BRS applications. Specifically, the resulting Zn-0.5Mg-WC nanocomposite's microstructure, mechanical properties, in vitro CR, and thermal stability were evaluated. The Zn-0.5Mg-WC nanocomposite had excellent mechanical strength [ultimate tensile strength (UTS) > 250 MPa], elongation to failure (>30%), and a suitable in vitro CR (∼0.02 mm/y) for this clinical application. Moreover, the Zn-0.5Mg-WC nanocomposite survived 10 million cycles of tensile loading (stress ratio, R = 0.053) when the maximum stress was 80% of the yield stress. Its ductility was also retained during a 90-day thermal stability study, indicating an excellent shelf life. Stent prototypes were fabricated using this composition and were successfully deployed during bench testing without fracture. These results show that the Zn-0.5Mg-WC nanocomposite is a promising material for BRS applications. In vivo studies are underway to validate both biocompatibility, stent function, and degradation.

Can a self-expanding pediatric stent expand with an artery? Relationship of stent design to vascular biology

OBJECTIVES

A large-diameter, intravascular, self-expanding stent system capable of continued expansion during somatic and vascular growth was modeled with finite element analysis (FEA), manufactured and tested in an animal model.

BACKGROUND

Children can quickly outgrow intravascular stents. If a stent could expand after implantation in arteries this would be ideal for use in pediatric patients.

METHODS

Computer-aided design and FEA were used to design and manufacture large-diameter, self-expanding nitinol stents with both high and low chronic outward force (COF). Four distinct stents with similar designs but with variable lengths and strut thicknesses were manufactured. Fourteen of these stents were implanted in the abdominal aortas or iliac arteries of four juvenile swine.

RESULTS

All animals survived without complication to their designated time points of harvest (90 or 180-days), and all stents expanded to greater diameters than the adjacent non-stented artery. Luminal diameter growth was 34-49% and 20-23% for stented and non-stented segments, respectively. Histologic examination revealed variable degrees of the internal elastic lamina and/or medial disruption with a mean injury score ranging from 0.70 ± 0.56 to 1.23 ± 0.21 and low COF stents implanted in smaller arteries having a larger injury score. Inflammatory responses and stenosis formation were minimal and ranged from 0.50 ± 0.71 to 3.00 ± 0.00 and 5.52 ± 1.05% to 14.68 ± 9.12%, respectively. The stent's COF did not correlate with vessel expansion or vascular injury.

CONCLUSIONS

Self-expanding stents can mirror and even exceed somatic growth. Although longer-term testing is needed, it may be possible to custom tailor self-expanding stents to expand after arterial implantation in pediatric patients.

Percutaneous Implantation of Adult Sized Stents for Coarctation of the Aorta in Children ≤20 kg: A 12-Year Experience

BACKGROUND

Stent implantation (SI) is more effective than balloon angioplasty for the treatment of coarctation of the aorta (CoA). Due to technical factors, balloon angioplasty is more commonly performed in small patients. We sought to evaluate outcomes of percutaneous adult sized SI for the treatment of CoA in small patients.

METHODS

A single-center retrospective review of all patients ≤20 kg who underwent percutaneous adult sized SI for native or recurrent CoA from 2004 to 2015 was performed.

RESULTS

Thirty-nine patients (20 patients ≤10 kg) were identified, with 28 (71.8%) having recurrent CoA and 22 (56.4%) previously failed balloon angioplasty. At the time of SI, the median (range) patient age and weight were 1.1 (0.3-7.9) years and 10 (5.5-20.4) kg, respectively. SI resulted in significant improvements in the median gradient (26 mm Hg [interquartile range (IQR), 18-42] to 0 mm Hg [IQR, 0-2]; P< 0.05) and median minimum diameter (3.6 mm [IQR, 2.4-4.8] to 7.7 mm [IQR, 6.5-9.4]; P<0.05). Seven patients (18%) had procedural adverse events. Twenty-seven (69%) patients underwent elective reintervention at a median time of 49.3 (IQR, 26.5-63.2) months from SI, with 8 (21%) stents requiring repeat SI for stent fracture. Over a median follow-up of 67.2 (IQR, 33.8-116.1) months, 25 patients (69%) were without hypertension or blood pressure gradient. Three (11%) patients developed femoral arterial occlusion.

CONCLUSIONS

Adult sized SI is an alternative to surgical intervention for small patients with CoA. SI carries a risk of access-related complications, which may improve with the development of lower profile stents with adult sized maximum diameters.

Immediate results of percutaneous management of coarctation of the aorta: A 7-year single-centre experience

BACKGROUND

Coarctation of the aorta (CoA) is often treated percutaneously. The aim of this study was to describe the immediate results of percutaneous management of native aortic coarctation (NaCoA) and recoarctation of the aorta (ReCoA) at our institution.

METHODS

We identified all patients with NaCoA or ReCoA who underwent percutaneous dilatation by either balloon angioplasty (BAP) or endovascular stent implantation (ESI) between 2011 and 2017. Success was defined as a residual peak-to-peak gradient (PPG) <20 mmHg or a ≥50% reduction in the gradient if the pre-intervention PPG was <20 mmHg.

RESULTS

63 patients (median age 6.8 years, interquartile range [IQR] 0.4-14.2) were identified. Among 11 patients with NaCoA, 7 underwent BAP and 4 had ESI, and among 52 patients with ReCoA, 42 underwent BAP and 10 had ESI. In patients with NaCoA, BAP was successful in 71%, with median PPG decreasing from 32 mmHg (IQR 25-46) to 17 mmHg (IQR 4-23) (p = .02), and ESI was successful in 100%, with median PPG decreasing from 20 mmHg (IQR 14.5-40) to 2 mmHg (IQR 0-6) (p < .01). In patients with ReCoA, BAP was successful in 69%, with median PPG decreasing from 20 mmHg (IQR 16-31.3) to 9 mmHg (IQR 0-14.3) (p < .001), and ESI was successful in 100%, with median PPG decreasing from 18 mmHg (IQR 11.5-22.8) to 0 mmHg (IQR 0-3.5) (p < .01). ESI was more successful than BAP (p = .01). There was only one complication.

CONCLUSIONS

Percutaneous management of CoA is safe and effective in both NaCoA and ReCoA. Stent implantation is more effective than BAP.

Management of adults with coarctation of aorta

Coarctation of the aorta (CoA) is a relatively common congenital cardiac defect often causing few symptoms and therefore can be challenging to diagnose. The hallmark finding on physical examination is upper extremity hypertension, and for this reason, CoA should be considered in any young hypertensive patient, justifying measurement of lower extremity blood pressure at least once in these individuals. The presence of a significant pressure gradient between the arms and legs is highly suggestive of the diagnosis. Early diagnosis and treatment are important as long-term data consistently demonstrate that patients with CoA have a reduced life expectancy and increased risk of cardiovascular complications. Surgical repair has traditionally been the mainstay of therapy for correction, although advances in endovascular technology with covered stents or stent grafts permit nonsurgical approaches for the management of older children and adults with native CoA and complications. Persistent hypertension and vascular dysfunction can lead to an increased risk of coronary disease, which, remains the greatest cause of long-term mortality. Thus, blood pressure control and periodic reassessment with transthoracic echocardiography and three-dimensional imaging (computed tomography or cardiac magnetic resonance) for should be performed regularly as cardiovascular complications may occur decades after the intervention.

Our first experience in stenting of coarctation of aorta in infants and small children; A case series study

BACKGROUND

One of the congenital heart defects which can cause severe cardiac symptoms and cardiac failure in early childhood and neonatal duration is coarctation of aorta. Balloon angioplasty or surgical approach could be done for management of these defects. This study aimed to evaluate the efficacy and safety of coarctation stenting to improve the condition of these patients.

METHODS

Five patients with severe coarctation of aorta participated in this study. Balloon angioplasty performed for these patients initially. Each of five patients had a gradient decline after the initial balloon angioplasty, and againing gradients increased during the follow-up; then, they were treated by implanting a stent. We used Cook Formula stents for these patients.

RESULTS

The pressure gradient decreased in all 5 patients with maximum and minimum reduction of 55 and 35 mmHg; and we had not severe complication during or after the procedure and during the follow-up period.

CONCLUSION

Performing a stent in selected small children and infants that have sever and symptomatic coarctation of aorta can be effective and safe in improving patients' clinical state, and preventing surgery.

Stent Angioplasty for Critical Native Aortic Coarctation in Three Infants: Up to 15-Year Follow-Up Without Surgical Intervention and Review of the Literature

Management of neonatal native coarctation is debated till now. Surgical therapy remains an option but may be unwarranted in critically sick infants with complex lesions. Balloon dilatation has been employed but with early re-stenosis. Stent angioplasty has also been used but as a bridge towards definitive surgical therapy. Four critically sick infants with complex coarctation and additional co-morbidity factors underwent primary stent therapy as surgical intervention was denied. One patient had died earlier due to reasons unrelated to the procedure. Three survivors underwent multiple dilatations of primary stents as indicated. One of the three survivors did not require any further dilatation after the age of 5 years and remained stable till the time of reporting. High-pressure Cheatham Platinum stents were implanted inside the primary stents in two infants, who developed re-stenosis due to somatic growth. These stents were further balloon dilated at high atmospheric pressure. Femoral arteries in both of them were blocked but were re-canalized after balloon dilatation in one and stent angioplasty in the other. After a follow-up of about 15 years, all of them have been doing fine with acceptable Doppler gradients. They were normotensive and on no cardiac medications. It can be concluded that, though surgical repair remains a standard of care, stent angioplasty in selected infants with complex lesions is feasible and effective. Multiple dilatations can be performed without added risk of stent migration. Bio-absorbable and growth stents hold a promise for future use in such situations.

Current Transcatheter Approaches for the Treatment of Aortic Coarctation in Children and Adults

Coarctation of the aorta is a common congenital heart defect and can present at any age. Infants may carry a fetal diagnosis, or are generally diagnosed after auscultation of a murmur, although rarely present in shock. Those that escape early childhood detection typically present in adolescence and adulthood, generally with upper-extremity hypertension. Percutaneous therapies have evolved to include balloon angioplasty and stent placement, and generally are the preferred first-line therapy for most adolescent/adult patients. Percutaneous interventions are now viable options in younger and smaller patients. The advent of bioresorbable stents may provide further expansion of treatment options to very small patients.

Complications After Stent Placement for Aortic Coarctation: A Pictorial Essay of Computed Tomographic Angiography

Stent placement is commonly used to treat aortic coarctation. Although invasive angiography remains the gold standard, follow-up is often performed using computed tomography, which allows rapid, noninvasive assessment of the aorta and surrounding tissues. The goal of this pictorial essay is to provide a guide to the interpretation of these examinations. Normal and abnormal computed tomographic appearance of different stent types is shown along with reconstructions that can help assess stent integrity and the stent position in relation to the aortic wall and branches. Furthermore, imaging findings of complications including aortic wall injuries, restenosis, and intimal hyperplasia are depicted.

Coarctation repair-redo challenges in the adults: what to do?

Aortic coarctation is one of the most common congenital cardiac pathologies. Repair of native aortic coarctation is nowadays a common and safe procedure. However, late complications, including re-coarctation and aneurysm formation, are not uncommon. The incidence of these complications is dependent on the type of the initial operation. Both endovascular and conventional open repair play important roles in the treatment of late complications after previous coarctation repair. This article will review the incidence of late complications after coarctation repair and will discuss the treatment options for redo coarctation repair in adult patients.

Stent Therapy for Aortic Coarctation in Children <30 kg: Use of the Low Profile Valeo Stent

To report our experience of coarctation stent therapy in small children weighing less than 30 kg, with the low profile dilatable Valeo stent and review the literature on coarctation stent therapy in this patient population. Coarctation stent implantation was undertaken in 14 consecutive children using the Bard Valeo Stent. Demographic, angiographic, echocardiographic and clinical data were reviewed retrospectively. The median age at the time of procedure was 5.1 (2.6-7.5) years and median weight was 20.8 (14.7-27) kg. There was improvement in median coarctation diameter from 4 (1.3-5.2) to 9.5 (5.8-12.7) mm, p < 0.001; and a reduction in the median peak pressure gradient across the coarctation from 35 (20-49) to 9 (0-15) mmHg, p < 0.001. Median stent recoil was 7.9 (0-20)%. There was one case of access related complication that resolved without sequelae. Follow-up was a median of 15 (3.0-57.2) months. CT angiogram performed at a median time of 3.3 (2.6-10.2) months post procedure showed no aortic wall injury and preserved stent integrity in all cases. Two children underwent re-intervention for stent dilation and further stent implantation due to in-stent stenosis and somatic growth after 3 years. Six of fourteen children remained on a single antihypertensive agent post-intervention at last follow-up. Implantation of the dilatable Valeo stent is a feasible treatment strategy in native or recurrent coarctation in small children, accepting that additional stent implantation may be necessary with somatic growth. Further study is required to determine longer-term stent efficacy and clinical outcome.

Avoidable costs of stenting for aortic coarctation in the United Kingdom: an economic model

BACKGROUND

Undesirable outcomes in health care are associated with patient harm and substantial excess costs. Coarctation of the aorta (CoA), one of the most common congenital heart diseases, can be repaired with stenting but requires monitoring and subsequent interventions to detect and treat disease recurrence and aortic wall injuries. Avoidable costs associated with stenting in patients with CoA are unknown.

METHODS

We developed an economic model to calculate potentially avoidable costs in stenting treatment of CoA in the United Kingdom over 5 years. We calculated baseline costs for the intervention and potentially avoidable complications and follow-up interventions and compared these to the costs in hypothetical scenarios with improved treatment effectiveness and complication rates.

RESULTS

Baseline costs were £16 688 ($25 182) per patient. Avoidable costs ranged from £137 ($207) per patient in a scenario assuming a 10% reduction in aortic wall injuries and reinterventions at follow-up, to £1627 ($2455) in a Best-case scenario with 100% treatment success and no complications. Overall costs in the Best-case scenario were 90.2% of overall costs at Baseline. Reintervention rate at follow-up was identified as most influential lever for overall costs. Probabilistic sensitivity analysis showed a considerable degree of uncertainty for avoidable costs with widely overlapping 95% confidence intervals.

CONCLUSIONS

Significant improvements in the treatment effectiveness and reductions in complication rates are required to realize discernible cost savings. Up to 10% of total baseline costs could be avoided in the best-case scenario. This highlights the need to pursue patient-specific treatment approaches which promise optimal outcomes.

Stent Repair for Complex Coarctation of Aorta

OBJECTIVES

This study sought to determine whether several anatomic or evolving characteristics of the coarctation may create challenging conditions for treatment.

BACKGROUND

Stent repair of coarctation of aorta is an alternative to surgical correction.

METHODS

We analyzed our 21-year experience in the percutaneous treatment of complex coarctation of aorta. Adverse conditions for treatment were as follow: 1) complete interruption of the aortic arch (n = 11); 2) associated aneurysm (n = 18); 3) complex stenosis (n = 30); and 4) the need for re-expansion and/or restenting (n = 21). Twenty patients (33%) belonged to more than 1 group. Ten interruptions were type A and 1 was type B. The mean length of the interrupted aorta was 9 ± 11 mm. The associated aneurysms were native in 8 patients and after previous intervention in 10 patients. Aneurysm shapes were fusiform in 8 patients and saccular in 10. The following characteristics defined complex stenosis as long diffuse stenosis, very tortuous coarctation, or stenosis involving a main branch or an unusual location. Patients previously stented at an early age, required re-expansion and/or restenting after reaching 16 ± 5 years of age.

RESULTS

Two patients had died by 1-month follow-up. The remaining 58 patients did well and were followed-up for a mean period of 10 ± 6 years. Late adverse events occurred in 3 patients (5%). All remaining patients are symptom-free, with normal baseline blood pressure. Imaging techniques revealed good patency at follow-up without associated aneurysm or restenosis. The actuarial survival free probability of all complex patients at 15 years was 92%.

CONCLUSIONS

Stent repair of complex coarctation of aorta is feasible and safe. Initial results are maintained at later follow-up.

Early and Long-Term Results of Stent Implantation for Aortic Coarctation in Pediatric Patients Compared to Adolescents: A Single Center Experience

Background. Stents have become the treatment of choice for native aortic coarctation in adults and adolescents, but in pediatric patients insufficient data are currently available to identify the best therapeutic option. Methods. To compare the outcomes of pediatric and adolescent patients, we retrospectively evaluated early and long-term results of stenting for aortic coarctation in 34 patients divided into 2 groups (A and B) composed, respectively, of 17 children (mean age 8.2 ± 2.3, weight ≤30 kg) and 17 adolescents (mean age 14.3 ± 1.7, weight >30 kg). Results. No significant differences in outcome were found between groups immediately after the procedure. In all of our patients, peak systolic gradient pressure significantly decreased after stenting from 43.7 ± 12 to 1.7 ± 3.1 mmHg in group A and from 39.4 ± 16.8 to 1.6 ± 3 in group B (p < 0.0001). We observed early and late adverse events in both groups: early femoral vessel injury or thrombosis was more frequent in younger patients, as well as restenosis due to vessel growth requiring stent redilatations, often complicated by stent fractures. Data from long-term follow-up showed that, in younger patients, stress-related hypertension was more frequent. Conclusions. The procedure was immediately safe and effective in both groups. Pediatric patients must be accurately selected before stenting because they could probably need reinterventions and stents could impact on their future therapeutic perspectives.

Coarctation of the aorta: Management from infancy to adulthood

Coarctation of the aorta is a relatively common form of congenital heart disease, with an estimated incidence of approximately 3 cases per 10000 births. Coarctation is a heterogeneous lesion which may present across all age ranges, with varying clinical symptoms, in isolation, or in association with other cardiac defects. The first surgical repair of aortic coarctation was described in 1944, and since that time, several other surgical techniques have been developed and modified. Additionally, transcatheter balloon angioplasty and endovascular stent placement offer less invasive approaches for the treatment of coarctation of the aorta for some patients. While overall morbidity and mortality rates are low for patients undergoing intervention for coarctation, both surgical and transcatheter interventions are not free from adverse outcomes. Therefore, patients must be followed closely over their lifetime for complications such as recoarctation, aortic aneurysm, persistent hypertension, and changes in any associated cardiac defects. Considerable effort has been expended investigating the utility and outcomes of various treatment approaches for aortic coarctation, which are heavily influenced by a patient’s anatomy, size, age, and clinical course. Here we review indications for intervention, describe and compare surgical and transcatheter techniques for management of coarctation, and explore the associated outcomes in both children and adults.

Intravascular stent therapy for coarctation of the aorta

Intravascular stent therapy is considered a primary therapeutic option for most adults and adolescents with coarctation of the aorta. This review highlights the indications, technical considerations, procedural aspects, and limited long-term outcome data when using this intervention. Stent technology has continued to evolve with potential for further modifications since its inception in the early 1990s. The best therapeutic approach, e.g., stenting versus surgery, in the treatment of native coarctation continues to be debated due to the paucity of long-term clinical and imaging data in both groups.

Coarctation of the aorta: management, indications for intervention, and advances in care

OPINION STATEMENT

Coarctation of the aorta (CoAo) accounts for 9 % of congenital heart defects. Balloon angioplasty has been the conventional endovascular treatment of choice for both native and recurrent coarctation in adults. Recent advancement in stent technology with the development of the covered stents has enhanced the scope for percutaneous management of both native CoAo and post-surgical CoAo. Stent implantation provides better hemodynamic results with larger acute diameter gain and better long-term hemodynamic benefit. Stenting also decreases the incidence of aneurysm formation. The development of biodegradable stents may revolutionize the percutaneous management of coarctation, as the degradation of the stent scaffold within 6 months of implantation will further decrease the incidence of restenosis. In the future stenting may suffice and obviate the need for open repair. Until then, surgical repair of CoAo is the preferred method in both infants and complicated lesions, leaving stenting to adults with focal and uncomplicated disease.

Coarctation of the aorta - the current state of surgical and transcatheter therapies

Aortic coarctation represents a distinct anatomic obstruction as blood moves from the ascending to the descending aorta and can present in a range of ages from infancy to adulthood. While it is often an isolated and discrete narrowing, it can also be seen in the more extreme scenario of severe arch hypoplasia as seen in the hypoplastic left heart syndrome or in conjunction with numerous other congenital heart defects. Since the first description of an anatomic surgical repair over sixty years ago, an evolution of both surgical and transcatheter therapies has occurred allowing clinicians to manage and treat this disease with excellent results and low morbidity and mortality. This review focuses on the current state of both transcatheter and surgical therapies, paying special attention to recent data on long-term follow-up of both approaches. Further, current thoughts will be explored about future therapeutic options that attempt to improve upon historical long-term outcomes.

Using the Valeo dilatable stent in coarctation stenting for small children: expanding the inclusion criteria for coarctation stenting?

The application of coarctation stenting has grown in paediatric and adult practice in recent years. Stent and delivery sheath technology has improved; however, we remain technically limited when implanting small calibre stents through small sheaths in small children, which then have the potential to be dilated to adult size as time passes. We describe the first reported use of the Valeo Biliary Pre-mounted Re-dilatable Stent (Edwards Life Sciences, California, USA) in aortic coarctation with 1 year follow-up including cross-sectional imaging. This 14 kg 3-year-old girl presented following an intracerebral haemorrhage secondary to severe systemic hypertension. Despite implantation through a 7-French sheath, this stent can be postdilated up to 20 mm, and therefore provides an important new addition to the interventional armamentarium.

Endovascular treatment of a congenital thoracic aortic aneurysm in a premature newborn

Congenital aortic aneurysms are a rare, life-threatening disorder that present complex treatment challenges. The authors describe a congenital thoracic aortic aneurysm treated by endovascular means with stent-assisted coil deployment. Because of rapid in utero aneurysm growth and cardiac dysfunction, a 2.6-kg male was delivered expeditiously by Cesarean section at 35(2)/(7) weeks' gestation. On day of life 1, bilateral femoral arterial access was used to deliver a balloon-expandable stent across the wide-necked aneurysm. Microcoil embolization of the aneurysm via a prepositioned microcatheter was then performed. The child had an uncomplicated hospital course and is asymptomatic 5 months later, with complete aneurysm thrombosis.

Computational fluid dynamic simulations of aortic coarctation comparing the effects of surgical- and stent-based treatments on aortic compliance and ventricular workload

OBJECTIVES

In this work, we examine the effects of stent-induced aortic stiffness on cardiac workload and blood pressure using computational fluid dynamic simulations.

BACKGROUND

Treatment of aortic coarctation (CoA) consists of either open, surgical repair or angioplasty with or without stenting. Although stenting is a minimally invasive alternative to surgery, aortic stiffness increases in the stented section. Concern over this increased stiffness has long been argued to be detrimental to the overall vascular health of the patient.

METHODS

MR imaging was performed on a 15-year-old female with CoA. A 3D model of the large thoracic arteries was created, and the heart and downstream vasculature were represented by lumped parameter models at the model inlet and outlets, respectively. A deformable wall assumption was used in conjunction with variable wall properties and tissue support, and 3D velocity, pressure, and wall dynamics were computed. The lumped parameter values and wall properties were tuned to match the mean flow and aortic deformation as measured by MRI. The CoA was then virtually removed from the model representing an end-to-end surgical correction. In a second model, the repaired section was prescribed to be nearly rigid, representing stenting. All other variables remained the same.

RESULTS

When compared to surgery, stenting resulted in clinically negligible increases in cardiac work (0.4%) and no change in mean blood pressure.

CONCLUSIONS

This pilot study suggests CoA stenting may not affect cardiac work to any significant degree as is commonly believed in the clinical community.

Endovascular stent placement is an acceptable alternative to reoperation in selected infants with residual or recurrent aortic arch obstruction

OBJECTIVE

To describe endovascular stent placement in infants as a technically feasible option in circumstances where surgery is considered less favorable.

BACKGROUND

Endovascular stent placement has become established as a first line therapy for native coarctation of the aorta or recoarctation in older children where stents capable of expansion to adult size can be placed safely. Surgery remains the therapy of choice in infants and young children. The management of aortic arch obstruction in infants is, however, frequently complicated by complex anatomy or clinical condition that may make surgery or further surgery an unattractive option. There is little reported data and the implications thereof of transcatheter stent placement in aortic arch obstruction in infants.

METHODS

Between August 2004 and November 2009, 11 patients had aortic arch obstruction treated with endovascular stent placement. The median age and weight at first stent placement was 46 days (range 3-399 days) and 4 kg (range 1.4-8 kg), respectively. In 10 patients, surgical intervention preceded transcatheter stent placement. Four had complex aortic arch obstruction and seven had recoarctation.

RESULTS

Reduction in peak systolic gradient to <10 mm Hg was achieved in seven of 10 patients with an improvement in aortic artery diameter to >90% of adjacent aorta in all. The diameter of the arch obstruction increased from a median of 1.60 to 4.90 mm (P = 0.001) and the peak systolic gradient from 45 mm Hg to 8 mm Hg (P < 0.0001). Adverse events occurred in two patients one who required further surgical revision and a second who required placement of a second stent. The median follow up was 3.60 years (range 0.4-5.5 years) with two patients having died at 1.34 and 1.42 years poststent placement. Of the nine patients alive, six have since undergone further angioplasty at a median time interval of 0.77 years (range 0.17-2.76 years). Long-term complications occurred in none.

CONCLUSIONS

Endovascular stent placement in infants is technically feasible with good results achievable even in small babies. It should be considered as a therapeutic option in complex cases when surgical alternatives are less favorable.

Pediatric interventional cardiology: 2009

PURPOSE OF REVIEW

Pediatric interventional cardiology has evolved quite dramatically over the past few decades and now, in 2009, the published literature continues to evolve new percutaneous strategies for managing patients with congenital heart disease, both simple and complex. Our goal for this review was to highlight new techniques and the new devices available to the pediatric interventional cardiologist, and to review the outcomes from past endeavors.

RECENT FINDINGS

Manuscripts published in the past year continue to demonstrate innovation; indicating an exciting and increasing experience of transcatheter treatment of septal communications using either new occluder devices or novel techniques. Bioabsorbable devices and percutaneously implanted valves are leading examples of technological improvements and creativity that will ultimately improve patient outcomes while minimizing invasiveness. Reports on procedural outcomes show technically safe early follow-up, with promising mid-term and long-term results for balloon valvuloplasty, balloon atrial septostomy and pulmonary artery stent implantation. As well, fetal and hybrid interventions have become important new arenas for the pediatric interventionist.

SUMMARY

Pediatric interventions have grown far beyond the early stages of the 1980s as mid-term and long-term outcome data are being reported, and many previously insurmountable hurdles have been overcome by developing new strategies and devices.