Balloon angioplasty for aortic recoarctation: results of Valvuloplasty and Angioplasty of Congenital Anomalies Registry

Balloon Dilatation in the Management of Congenital Obstructive Lesions of the Heart: Review of Author's Experiences and Observations-Part I

Balloon dilatation techniques became available to treat congenital obstructive lesions of the heart in the early/mid-1980s. The purpose of this review is to present the author's experiences and observations on the techniques and outcomes of balloon dilatation of pulmonary stenosis (PS), aortic stenosis (AS) and aortic coarctation (AC), both native and postsurgical re-coarctations. Balloon dilatation resulted in a reduction of peak pressure gradient across the obstructive lesion at the time of the procedure as well as at short-term and long-term follow-ups. Complications such as recurrence of stenosis, valvar insufficiency (for PS and AS cases) and aneurysm formation (for AC cases) have been reported, but infrequently. It was recommended that strategies be developed to prevent the reported complications.

Personalized Pre- and Post-Operative Hemodynamic Assessment of Aortic Coarctation from 3D Rotational Angiography

PURPOSE

Coarctation of Aorta (CoA) is a congenital disease consisting of a narrowing that obstructs the systemic blood flow. This proof-of-concept study aimed to develop a framework for automatically and robustly personalizing aortic hemodynamic computations for the assessment of pre- and post-intervention CoA patients from 3D rotational angiography (3DRA) data.

METHODS

We propose a framework that combines hemodynamic modelling and machine learning (ML) based techniques, and rely on 3DRA data for non-invasive pressure computation in CoA patients. The key features of our framework are a parameter estimation method for calibrating inlet and outlet boundary conditions, and regional mechanical wall properties, to ensure that the computational results match the patient-specific measurements, and an improved ML based pressure drop model capable of predicting the instantaneous pressure drop for a wide range of flow conditions and anatomical CoA variations.

RESULTS

We evaluated the framework by investigating 6 patient datasets, under pre- and post-operative setting, and, since all calibration procedures converged successfully, the proposed approach is deemed robust. We compared the peak-to-peak and the cycle-averaged pressure drop computed using the reduced-order hemodynamic model with the catheter based measurements, before and after virtual and actual stenting. The mean absolute error for the peak-to-peak pressure drop, which is the most relevant measure for clinical decision making, was 2.98 mmHg for the pre- and 2.11 mmHg for the post-operative setting. Moreover, the proposed method is computationally efficient: the average execution time was of only [Formula: see text] minutes on a standard hardware configuration.

CONCLUSION

The use of 3DRA for hemodynamic modelling could allow for a complete hemodynamic assessment, as well as virtual interventions or surgeries and predictive modeling. However, before such an approach can be used routinely, significant advancements are required for automating the workflow.

Cerebral Ischemia after Stenting of Coarctation of the Aorta

Percutaneous stenting angioplasty of native coarctation of the aorta is considered a low-risk procedure with high success rate. The incidence of cerebral complications, especially ischemic complications, is very low. We report a case of a 15-year-old boy who underwent a percutaneous stenting angioplasty for a coarctation of the aorta and developed a cerebral infraction 4 hours after the procedure.

Balloon Angioplasty for Native Aortic Coarctation in 3- to 12-Month-Old Infants

BACKGROUND

Balloon angioplasty for native coarctation of the aorta (CoA) is successful in children and adults but in neonates results in frequent restenosis. The efficacy of balloon angioplasty for native CoA during infancy beyond the neonatal period was examined in infants aged 3 to 12 months of age.

METHODS

A retrospective review of 68 infants who underwent balloon angioplasty for native CoA. 95% CI are in parentheses.

RESULTS

Procedural age was (mean±SD) 6±3.4 months and weight was 7±1.8 kg. Balloon angioplasty produced a large decrease in both the noninvasive arm-to-leg blood pressure gradient (41.2±18.7 to 5.6±9.6 mm Hg) and the invasive peak systolic pressure gradient (34±12 to 11±9 mm Hg). Balloon angioplasty increased the CoA diameter from 2.7±1 mm to 4.6±1.2 mm. One patient was lost to follow-up. A catheter reintervention was required in 11.8% and surgery in 10.3%. The hazard of reintervention was highest early. Median freedom from reintervention was 89% (95% CI, 80%-96%) at 1 year, 83% (95% CI, 73%-92%) at 5 years, and 81% (95% CI, 69%-90%) at 10 years. Femoral artery thrombosis was documented in 6 (9%) infants without any long-term consequence. One patient developed a small aortic aneurysm late and has not required treatment. A robust estimate of the frequency of aortic aneurysms remains to be determined as the majority of subjects have not had cross-sectional imaging.

CONCLUSIONS

Balloon angioplasty of native CoA is effective and safe in infants aged 3 to 12 months with outcomes comparable to those in older children and adults. Catheter reinterventions can avoid the need for surgery in most patients.

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.

Histopathological evaluation of aortic coarctation after conventional balloon angioplasty in neonates

BACKGROUND

Optimal management strategy for native aortic coarctation in neonates and young infants is still a matter of debate. The surgical procedure, histopathologic research, and clinical outcome in 15 neonates who underwent surgery after successful balloon angioplasty is the basis of this study.

METHOD

Between 01 October, 2014 and 01 August, 2017, we enrolled 15 patients with native aortic coarctation for this study. These patients had complications regarding recoarctation, following balloon angioplasty intervention at our institute and other centres. Surgically extracted parts were examined histopathologically and patient's data were collected retrospectively.ResultThe reasons for recurrence of recoarctation after balloon angioplasty are as follows: patients with higher preoperative echocardiographic gradients had recoarctation earlier, neointimal proliferation, aortic intimal fibrosis at the region of ductal insertion, and ductal residual tissue debris after balloon angioplasty. No repeat intervention was required in the 15 patients who underwent surgery followed by balloon angioplasty. Early mortality was seen in one patient after surgery. Postoperative complication in the surgical group occurred in the form of chylothorax in one patient.

CONCLUSION

In centres in which the neonatal ICU is inexperienced, balloon angioplasty is particularly recommended. In developing neonatal clinics, balloon angioplasty, when performed on patients at their earliest possible age, delays actual corrective operation to a later date, which in turn provides less risky surgical outcomes in infants who are gaining weight, growing, and do not have any haemodynamic complaints.

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.

Therapeutic Utilities of Pediatric Cardiac Catheterization

In an era when less invasive techniques are favored, therapeutic cardiac catheterization constantly evolves and widens its spectrum of usage in the pediatric population. The advent of sophisticated devices and well-designed equipment has made the management of many congenital cardiac lesions more efficient and safer, while providing more comfort to the patient. Nowadays, a large variety of heart diseases are managed with transcatheter techniques, such as patent foramen ovale, atrial and ventricular septal defects, valve stenosis, patent ductus arteriosus, aortic coarctation, pulmonary artery and vein stenosis and arteriovenous malformations. Moreover, hybrid procedures and catheter ablation have opened new paths in the treatment of complex cardiac lesions and arrhythmias, respectively. In this article, the main therapeutic utilities of cardiac catheterization in children are discussed.

Endovascular Techniques in Adult Aortic Coarctation: The Use of Stents for Native and Recurrent Coarctation Repair

Purpose:

To report initial experiences with stent implantation in the treatment of native and recurrent aortic coarctation in adults.

Methods:

Two adult patients were diagnosed with aortic coarctation: in one, the native aorta was involved, and in the other, the stenosis involved a prior coarctation repair. Both patients were offered and selected angioplasty with possible stent implantation as an alternative to surgery.

Results:

In the patient with recurrent narrowing, thrombolysis and balloon dilation preceded the successful deployment of three Palmaz stents along the grafted segment. In the case of native disease, one Palmaz stent was implanted primarily at the site of a critical, focal stenosis. No complications were encountered, and recovery was uneventful. Follow-up at 12 and 6 months, respectively, showed sustained clinical improvement with resolution of symptoms and excellent hemodynamic values.

Conclusion:

The positive outcome in these early cases supports further evaluation of the efficacy of adjunctive or primary stenting for treatment of native or recurrent aortic coarctation in adults.

Recurrent coarctation: interventional techniques and results

Coarctation of the aorta (CoA) accounts for 5% to 8% of all congenital heart defects. With all forms of interventions for native CoA, repeat intervention may be required due to restenosis and/or aneurysm formation. Restenosis rates vary from 5% to 24% and are higher in infants and children and in those with arch hypoplasia. Although repeat surgery can be done for recurrent CoA, guidelines from a number of professional societies have recommended balloon angioplasty with or without stenting as the preferred intervention for patients with isolated recoarctation. For infants and young children with recurrent coarctation, balloon angioplasty has been shown to be safe and effective with low incidence of complications. However, the rates of restenosis and reinterventions are high with balloon angioplasty alone. Endovascular stent placement is indicated, either electively in adults or as a bailout procedure in those who develop a complication such as dissection or intimal tear after balloon angioplasty. Conventionally bare metal stents are used; these can be dilated later if required. Covered stents, introduced more recently, are best reserved for those who have aneurysm at the site of previous repair or who develop a complication such as aortic wall perforation or tear. Stents produce complete abolition of gradients across the coarct segment in a majority of cases with good opening of the lumen on angiography. The long-term results are better than that of balloon angioplasty alone, with very low rates of restenosis. However, endovascular stenting is a technically demanding procedure and can be associated with serious complications rarely.

Percutaneous angioplasty used to manage native and recurrent coarctation of the aorta in infants younger than 1 year: immediate and midterm results

Balloon angioplasty (BAP) used to manage native coarctation of the aorta (CoAo) in infants remains controversial. This study aimed to compare short- and midterm results of BAP between native CoAo (NaCo) and postsurgical recoarctations (ReCo) in infants younger than 1 year. This retrospective study compared the clinical, echocardiographic, hemodynamic, and angiographic data for infants who underwent BAP between July 2003 and September 2012. The 12 NaCo and 13 ReCo patients in this study underwent BAP at 4.61 ± 3.69 and 4.88 ± 3.07 months (p = 0.84) and weighed 5.49 ± 2.57 and 6.10 ± 2.11 kg (p = 0.52), respectively. Their respective heights were 60.58 ± 10.58 and 61.15 ± 6.74 cm (p = 0.87). All the ReCo patients had their initial surgery before the age of 3 months. The minimal CoAo diameter was 2.81 ± 0.96 mm in the NaCo group and 2.86 ± 1.0 mm in the ReCo group (p = 0.90). The relative gradient reduction was 62.79 ± 32.43 % in the NaCo group and 73.37 ± 20.78 % in the ReCo group (p = 0.33). The in situ complication rate (pseudoaneurysm) was 8.33 % in the NaCo group and 7.69 % in the ReCo group (p = 0.74). During the early follow-up evaluation, five NaCo patients (41.66 %) presented with recoarctation requiring BAP reintervention within 1.75 ± 1.41 months (all had their initial BAP before 3 months of age) compared with 1 ReCo patient (7.69 %) (p = 0.165). The mean follow-up period was 3.09 ± 2.69 years for the NaCo patients and 3.6 ± 3.18 years for the ReCo patients (p = 0.69), during which the blood pressure gradient was 12.33 ± 9.67 for the NaCo patients and 7.80 ± 8.78 for the ReCo patients (p = 0.17), with corresponding Doppler peak instantaneous gradients of 21.29 ± 11.19 and 16.20 ± 10.23 (p = 0.24). The resultant diameter ratio between the minimal isthmus diameter and the aortic diameter at the diaphragmatic level was 0.81 ± 0.15 in the NaCo group and 0.85 ± 0.12 in the ReCo group (p = 0.53). The immediate and midterm results of BAP for the NaCo and ReCo infants were comparable. Accordingly, BAP seems to be an acceptable alternative to surgery for infants older than 3 months.

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 Stent Trial (COAST): study design and rationale

BACKGROUND

Coarctation of the aorta (CoA) accounts for 4% to 5% of congenital cardiac abnormalities. Stent therapy has become an accepted alternative to surgery for older children and adults, although there are no balloon-expandable stents approved by the Food and Drug Administration for use in the aorta. The Cheatham-Platinum (CP) stent was designed for CoA therapy and is widely used outside the United States. We have designed the first prospective trial of stent therapy for CoA to serve as the pivotal trial for Food and Drug Administration approval of the CP stent.

METHODS

The COAST study is a prospective, multicenter, single-arm clinical study. The population includes patients with native or recurrent CoA. Four primary outcome variables were defined. For each variable, the stent will be compared to performance guidelines derived from surgical experience. The first efficacy outcome is reduction in arm-leg systolic blood pressure gradient, and the second is reduction in hospital length of stay. Safety outcomes include the following: the occurrence of any serious or somewhat serious adverse event attributed to the stent or implantation procedure and the occurrence of postprocedure paradoxical hypertension. A total of 105 patients treated with the CP stent will be enrolled.

DISCUSSION

To ascertain the effectiveness and safety of an interventional device, randomized controlled trials have been offered as the criterion standard. However, these trials are not well suited to study rare conditions such as CoA, especially once the therapy in question has received acceptance within the medical community. New clinical trial and statistical approaches are needed to evaluate such therapies. The COAST study is an example of this kind of innovative trial design.

The Fontan Connections: Past, Present, and Future

The Fontan procedure is now considered the final common pathway for patients with anatomical or functional single ventricle. These patients initially have their systemic and pulmonary circulations in parallel, supported by one functional ventricular chamber. The ultimate goal with this procedure is to separate the two circulations, to prevent mixing of venous and arterial blood, and to provide adequate tissue oxygenation. The objective of this article is to review the Fontan procedure with its various modifications and refinements since its introduction to clinical practice in 1971, by Fontan and Baudet.

Results of stent implantation for native and recurrent coarctation of the aorta-follow-up of up to 13 years

BACKGROUND

To evaluate the mid and long-term prognosis after stenting of native or recurrent CoA, we studied the cardiovascular parameters in the follow-up period up to 13 years.

METHODS AND RESULTS

Between 1993 and 2006, 68 patients underwent stent implantation for aortic coarctation (average age 25.5 years, range 5.7-65 years, average weight 65.5 kg, range 32-122 kg). Forty-six (68%) patients were aged >17 years. Stenting was performed for native coarctation in 41 and for recurrent coarctation in 27 patients, in 23 (34%) patients with a covered stent. Redilation was carried out in 26 (38%) patients. The invasive systolic gradient decreased from mean (±SD) 25 (±15) mm Hg to 5 (±5) mm Hg (P < 0.0005). The descending aorta pressure increased from 80 (±15) mm Hg to 101 (±18) mm Hg. The systolic right arm blood pressure decreased from a mean of 153 (±24) mm Hg to 129 (±18) mm Hg (P < 0.0005). Complications like small dissections were rare. Follow-up (6 days to 13 years, mean 41 months) was available in 66 patients, in 23 after reintervention at a mean of 71 months, range of 8 months to 10.3 years. Fifty-one percent remained clinically hypertensive.

CONCLUSIONS

Stenting of aortic coarctation gives good medium-term results. Frequent reintervention relate to deliberately under-dilating stents during the initial procedure. The reintervention rate has reduced since the introduction of covered stents.

Endovascular management of coarctation of the aorta

Untreated thoracic aortic coarctation leads to early death predominantly because of hypertension and its cardiovascular sequelae. Surgical treatment has been available for > 50 years and has improved hypertension and survival. More recently, endovascular techniques have offered a minimally invasive alternative to traditional open repair. Early and intermediate results suggest angioplasty and stenting have an important role in the management of aortic coarctation, particularly in adults and older children.

AORTIC COARCTATION: RECENT DEVELOPMENTS IN EXPERIMENTAL AND COMPUTATIONAL METHODS TO ASSESS TREATMENTS FOR THIS SIMPLE CONDITION

Coarctation of the aorta (CoA) is often considered a relatively simple disease, but long-term outcomes suggest otherwise as life expectancies are decades less than in the average population and substantial morbidity often exists. What follows is an expanded version of collective work conducted by the authors' and numerous collaborators that was presented at the 1st International Conference on Computational Simulation in Congenital Heart Disease pertaining to recent advances for CoA. The work begins by focusing on what is known about blood flow, pressure and indices of wall shear stress (WSS) in patients with normal vascular anatomy from both clinical imaging and the use of computational fluid dynamics (CFD) techniques. Hemodynamic alterations observed in CFD studies from untreated CoA patients and those undergoing surgical or interventional treatment are subsequently discussed. The impact of surgical approach, stent design and valve morphology are also presented for these patient populations. Finally, recent work from a representative experimental animal model of CoA that may offer insight into proposed mechanisms of long-term morbidity in CoA is presented.

Fontan "Ten Commandments" revisited and revised

Choussat's "Ten Commandments," which describes the components of an ideal Fontan candidate, was first published in 1977. Despite the wisdom in these commandments, it is clear from a historic perspective that total compliance with all criteria does not necessarily portend excellent long-term survival. I believe the end point of the original commandments should be modified to include improvement in long-term survival. I suggest the following single commandment: "Thou Shalt Be Perfect."

Emergency covered stent implantation for rupture of the ascending aorta after balloon angioplasty

An acute rupture of the ascending aorta occurred in a 12-year-old boy after balloon angioplasty and was successfully treated by emergency covered stent implantation during resuscitation and preparation for support with extracorporeal membrane oxygenation. Neuroprotection with sedation, core temperature cooling and mild hyperventilation were undertaken. The boy recovered quickly. There were no neurological sequalae with a good interventional result at discharge and at follow-up after 9 months.

Coarctation of the aorta treated with the Advanta V12 large diameter stent: acute results

OBJECTIVES

To report on the early results of treatment of coarctation of the aorta by dilation with a new polytetrafluoroethylene covered stent.

BACKGROUND

Transcatheter dilation of aortic coarctation carries the risk of aneurysm or rupture. Covered stent implantation reduces this risk but requires a large delivery system. The Advanta V12 LD covered stent is premounted and requires a 9-11 Fr delivery system.

METHODS

Covered stents on balloons of a diameter sufficient to anchor the stent in the coarctation were implanted using the smallest available delivery system. Secondary dilation with larger diameter balloons was performed until the pressure gradient was <20 mm Hg and the stent was opposed to the aortic wall.

RESULTS

Twenty-five patients with aortic coarctation underwent stent implantation. Coarctation diameter increased from (6.3 + or - 3.5) mm to (14.4 + or - 2.3) mm (P < 0.0001). Peak pressure gradient decreased from (25.3 + or - 11.6) mm Hg to (2.5 + or - 3.0) mm Hg (P < 0.0001). The stent achieved the desired diameter in all cases. There were no complications. At short-term median follow-up of 4.9 months, all patients are alive and well with no evidence of recoarctation or aneurysm.

CONCLUSIONS

These initial results show that the covered Advanta V12LD stent is safe and effective in the immediate treatment of coarctation of the aorta through a low profile delivery system of 8-11 Fr. Long term follow up is required.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: outflow tract obstruction, coarctation of the aorta, tetralogy of Fallot, Ebstein anomaly and Marfan's syndrome

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. Part II of the guidelines includes recommendations for the care of patients with left ventricular outflow tract obstruction and bicuspid aortic valve disease, coarctation of the aorta, right ventricular outflow tract obstruction, tetralogy of Fallot, Ebstein anomaly and Marfan's syndrome. Topics addressed include genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy risk and follow-up requirements. The complete document consists of four manuscripts that are published online in the present issue of The Canadian Journal of Cardiology. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

The IMPACT registry: IMproving Pediatric and Adult Congenital Treatments

Tremendous advances have occurred in catheter-based interventions for congenital heart disease. Multicenter trials of these advances are either out of date or have been limited in scope. As such little is known on the application of these techniques in the current era. The IMPACT Registry (IMproving Pediatric and Adult Congenital Treatments) will allow us to measure variability in the performance and outcomes of both diagnostic and interventional cardiac catheterization procedures in all children and adults with congenital heart disease. The IMPACT Registry will be harmonized with the Society of Thoracic Surgeons Congenital Heart Disease Database, thereby allowing us to compare catheter-based interventions with surgical interventions when appropriate. The initial release of the registry will only include hospital-based outcomes, but ultimately it will transition to a longitudinal registry. The IMPACT Registry will provide the necessary benchmark tools for quality improvement activities for cardiac catheterization procedures in congenital heart disease.

Covered Cheatham-Platinum stents for serial dilation of severe native aortic coarctation

OBJECTIVES

To report on the early results of treatment of native coarctation of the aorta by implantation and serial dilations of covered stents.

BACKGROUND

Transcatheter dilation of native coarctation of the aorta carries a risk of aneurysm or rupture. Covered stent implantation requires a large delivery system with the risk of vascular damage.

METHODS

Covered stents on balloons of diameter sufficient to anchor the stent in the coarctation were implanted using the smallest delivery system possible. Dilation with larger diameter balloons was performed until the pressure gradient was <20 mm Hg and the stent was opposed to the aortic wall.

RESULTS

Twenty-two patients with native coarctation underwent stent implantation. Coarctation diameter increased from 3.6 +/- 1.9 to 12.6 +/- 1.9 mm (P < 0.001). Peak pressure gradient decreased from 29.4 +/- 8.5 to 6.7 +/- 5.7 mm Hg (P < 0.001). Nine patients underwent further dilation on average 5 months later. Residual pressure gradient decreased from 12.3 +/- 5.8 to 2.1 +/- 2.9 mm Hg (P = 0.002). The stent achieved the diameter of the transverse arch in all cases. Complications included a small tear at further dilation treated with a second stent and a femoral pseudoaneurysm. At short-term follow-up of 18.5 months all patients are alive and well with no evidence of recoarctation or aneurysm.

CONCLUSIONS

These initial results show that serial dilation of covered Cheatham-Platinum stents is feasible, safe, and an effective percutaneous method for the treatment of native coarctation of the aorta. However, long-term follow up is required.

Pediatric cardiac interventions

The field of pediatric cardiac interventions has witnessed a dramatic increase in the number and type of procedures performed. We review the most common procedures performed in the catheter laboratory. Lesions are divided according to their physiological characteristics into left-to-right shunting lesions (atrial septal defect, patent ductus arteriosus, ventricular septal defect), right-to-left shunting lesions (pulmonary stenosis, pulmonary atresia/intact ventricular septum), right heart obstructive lesions (peripheral arterial pulmonic stenosis, right ventricular outflow tract obstruction), and left heart obstructive lesions (aortic valve stenosis, coarctation of the aorta). In addition, a miscellaneous group of lesions is discussed.

The role of stents in the treatment of congenital heart disease: Current status and future perspectives

Intravascular or intracardiac stenoses occur in many forms of congenital heart disease (CHD). Therefore, the implantation of stents has become an accepted interventional procedure for stenotic lesions in pediatric cardiology. Furthermore, stents are know to be used to exclude vessel aneurysm or to ensure patency of existing or newly created intracardiac communications. With the further refinement of the first generation of devices, a variety of "modern" stents with different design characteristics have evolved. Despite the tremendous technical improvement over the last 20 years, the "ideal stent" has not yet been developed. Therefore, the pediatric interventionalist has to decide which stent is suitable for each lesion. On this basis, currently available stents are discussed in regard to their advantages and disadvantages for common application in CHD. New concepts and designs developed to overcome some of the existing problems, like the failure of adaptation to somatic growth, are presented. Thus, in the future, biodegradable or growth stents might replace the currently used generation of stents. This might truly lead to widening indications for the use of stents in the treatment of CHD.

Hybrid intraoperative pulmonary artery stent placement for congenital heart disease

Percutaneous branch pulmonary artery (PA) stenting can be challenging, especially in patients with stenosis of the right ventricular (RV) outflow tract or tortuous PA branches. In these cases, a hybrid procedure deploying PA stent(s) during cardiac surgery provides an alternative to relieve branch PA stenosis. The Mayo Clinic Congenital Cardiac surgical database was used to identify all patients having hybrid PA stent procedures. Retrospective analysis of clinical data, procedural details, and outcomes was performed. Between January 1997 and November 2006, 24 patients (15 females), median age 15 years (range 3 to 67 years), had hybrid PA stent procedures. A total of 27 stents were deployed. A left PA stent was placed in 13, right PA stent in 8; 3 patients had bilateral PA stents. Primary cardiac diagnoses were pulmonary atresia (9), tetralogy of Fallot (7), tricuspid atresia (2), and others (6). Maximum balloon diameters ranged from 8 to 16 mm (median = 12 mm). Concomitant surgical procedures performed were RV to PA conduit replacement or RV outflow tract reconstruction (14), pulmonary valve replacement (7), and others (3). Two procedures were performed following complications of percutaneous procedure. There were no deaths or PA damage. There were 2 cases of distal stent migration. Repeat stent dilations within 6 months were performed in 3 patients. In conclusion, hybrid PA stenting can play an important role in the management of congenital heart disease with complex branch PA anatomy. It also can be used as an emergency rescue procedure following complications of percutaneous transcatheter procedures, such as stent embolization. Hybrid procedures were safe and effective in most patients, although stent positioning remains critical. Intraoperative fluoroscopy and active suture fixation of the proximal stent may reduce the need for late reintervention.

Long-term (up to 20 years) results of percutaneous balloon angioplasty of recurrent aortic coarctation without use of stents

AIMS

To assess the efficacy, safety, and long-term results of the balloon angioplasty of recoarctation.

METHODS AND RESULTS

The angioplasty was performed in 99 consecutive patients aged 36 days to 32.6 years (median 268 days). Recoarctation to descending aorta diameter ratio increased from 0.44 (0.35/0.50) to 0.66 (0.57/0.77), P < 0.001. Systolic gradient was reduced from 34.0 (26.0/44.75) to 15.0 (8.25/27.0) mmHg, P < 0.001. In seven patients (7.1%) the procedure was ineffective. One patient (1%) with heart failure died within 24 h after a successful angioplasty and in another (1%) an intimal abruption necessitated surgical revision. The follow-up ranged up to 20.7 years (median 8.1 years). Actuarial probability of survival 20.7 years after the procedure was 0.91, and of reintervention-free survival was 0.44. Older age at the angioplasty was associated with a higher incidence of reinterventions (hazard ratio 1.057; 95% confidence interval 1.012-1.103; P = 0.010). The type of surgery and the recoarctation anatomy did not influence the outcome. In 69 patients aneurysm formation was studied by high-sensitive methods with only one positive finding per 462 patient-years.

CONCLUSION

Angioplasty is safe and effective regardless of the type of surgery used and the recoarctation anatomy. Older age at the angioplasty is associated with a higher incidence of reinterventions.

Balloon angioplasty of native coarctation and comparison of patients younger and older than 3 months

BACKGROUND

There is a high incidence of restenosis and aneurysm formation after balloon angioplasty for discrete native coarctation in neonates and young infants, and so the techniques remains controversial in this group of patients because its clinical validity, particularly in comparison with surgery, has not been well established.

METHODS AND RESULTS

From January 1999 to October 2005, group A (17 patients [8 males, 9 females] <3 months old ranging from 0.2 to 2.9 months, with a body weight of 2.5-5.5 kg) and group B (11 patients [5 males, 6 females] >3 months old ranging from 5.5 months to 6.4 years, with a body weight of 7.8-21 kg) with discrete native coarctation who underwent balloon angioplasty and were included in this study. There were 13 (76%) successes in group A, and 10 (90%) successes in group B for the initial balloon angioplasty. There was no significant difference in success rate between groups A and B (p>0.05). There were 9 (69%) cases of restenosis patients in group A, and 2 (20%) in group B, a significant difference between the 2 groups (p<0.05). In group A, 1 patient showed aneurysm formation after angioplasty, 1 (5.8%) showed femoral artery obstruction and 2 (11%) showed reduced pulses.

CONCLUSIONS

Balloon angioplasty of discrete native coarctation is effective in patients both younger and older than 3 months. However, thea rates of restenosis, aneurysm formation, and approach artery injury are higher in patients younger than 3 months old when compared with patients aged over 3 months. These complications should be considered when performing balloon angioplasty in patients less than 3 months of age.

Covered Cheatham-platinum stents for aortic coarctation: early and intermediate-term results

OBJECTIVES

This study sought to evaluate the use of covered Cheatham-platinum (CP) stents in the treatment of aortic coarctation (CoA).

BACKGROUND

Aortic aneurysms and stent fractures have been encountered after surgical and transcatheter treatment for CoA. Covered stents have previously been used in the treatment of abdominal and thoracic aneurysms in adults. We implanted covered CP stents as a rescue treatment in patients with CoA aneurysms or previous stent-related complications and in patients at risk of developing complications because of complex CoA anatomy or advanced age.

METHODS

Thirty-three covered CP stents were implanted in 30 patients; 16 patients had had previous procedures. The remaining patients had complex or near-atretic CoA.

RESULTS

The mean patient age and weight were 28 (+/-17.5) years (range 8 to 65 years), and 62 (+/-13) kg (range 28 to 86 kg), respectively. The systolic gradient across the CoA decreased from a mean (+/-SD) of 36 +/- 20 mm Hg before to a mean of 4 +/- 4 mm Hg after the procedure (p < 0.0001), and the diameter of the CoA increased from 6.4 +/- 3.8 mm to 17.1 +/- 3.1 mm (p < 0.0001). The follow-up period was up to 40 months (mean, 11 months). All stents were patent and in good position on computed tomography or magnetic resonance imaging performed three to six months later. In 43% of the patients antihypertensive medication was either decreased or stopped.

CONCLUSIONS

Covered CP stents may be used as the therapy of choice in patients with complications after CoA repairs, whereas they provide a safe alternative to conventional stenting in patients with severe and complex CoA lesions or advanced age.

Magnetic resonance imaging predictors of coarctation severity

BACKGROUND

MRI is increasingly used for anatomic assessment of aortic coarctation (CoA), but its ability to predict the transcatheter pressure gradient, considered the reference standard for hemodynamic severity, has not been studied in detail. This study evaluated the ability of MRI to distinguish between mild versus moderate and severe CoA as determined by cardiac catheterization.

METHODS AND RESULTS

The clinical, MRI, and catheterization data of 31 subjects referred for assessment of native or recurrent CoA were reviewed retrospectively. Patients were divided into 2 groups on the basis of peak coarctation gradient by catheterization: <20 mm Hg (n=12) and > or =20 mm Hg (n=19). Patients with cardiac index <2.2 L x min(-1) x m(-2) by catheterization were excluded. By logistic regression analysis, the following variables simultaneously predicted coarctation gradient > or =20 mm Hg: (1) smallest aortic cross-sectional area (adjusted for body surface area) measured by planimetry from gadolinium-enhanced 3D magnetic resonance angiography (OR 1.71 for 10 mm2/m2 decrease, P=0.005) and (2) heart rate-corrected mean flow deceleration in the descending aorta measured by phase-velocity cine MRI (OR 1.68 for 100 mL/s(1.5) increase, P=0.018). For the combination of these variables, a predicted probability >0.38 had 95% sensitivity, 82% specificity, 90% positive and negative predictive values, and an area under the receiver-operator characteristics curve of 0.938. In a subsequent validation study, the prediction model correctly classified 9 of 10 patients, with no false-negatives.

CONCLUSIONS

The combination of anatomic and flow data obtained by MRI provides a sensitive and specific test for predicting catheterization gradient > or =20 mm Hg.

Impact of re-coarctation following the Norwood operation on survival in the balloon angioplasty era

OBJECTIVES

The objective of this study was to determine the efficacy of balloon angioplasty (BA) by comparing the immediate and long-term outcomes of patients with and without re-coarctation after a Norwood procedure.

BACKGROUND

Although BA has become the standard means for treating recurrent coarctation following a Norwood operation, it has been suggested that re-coarctation remains a significant cause of morbidity and mortality.

METHODS

Patients who survived a Norwood operation from December 1986 through June 2001 were studied. Differences between groups were evaluated by t test and logistic regression. Survival differences were tested by log-rank tests using Kaplan-Meier survival curves.

RESULTS

Fifty-eight of 633 patients underwent treatment for re-coarctation (9.2%). Thirty-five patients underwent BA (before 1988, 23 had surgery). Median age at catheterization was 6.6 months (1.9 to 35.6 months). Balloon angioplasty was successful (gradient <10 mm Hg) in 32 of 35 patients (92%). There were no BA-related deaths or neurologic complications. Recurrent obstruction after BA occurred in seven patients (20%); five underwent re-dilation. Kaplan-Meier estimates of freedom from recurrent obstruction after initial BA were 97% at one month, 79% at one year, and 79% at five years. There were no differences in survival between patients with re-coarctation treated by BA and patients who did not undergo treatment for re-coarctation.

CONCLUSIONS

We found that 9.2% of patients underwent treatment for re-coarctation following a Norwood operation. Balloon angioplasty is effective, with low morbidity, no early mortality, and no difference in long-term survival when compared with patients who did not have re-coarctation. Recurrent coarctation following BA occurred in 17% of patients, usually within the first year after BA.

Initial experience using the NuMED Cheatham Platinum (CP) stent for interventional treatment of coarctation of the aorta in children and adolescents

We report the immediate results in a group of selected patients with native or recurrent coarctation of the aorta who underwent endovascular stent implantation using the newly designed Cheatham-Platinum (CP)-stent. The balloon-expandable stents were implanted in 6 patients (mean age 12.7 years) with coarctation of the aorta (5 native, 1 recurrent). The maximal systolic peak pressure gradient was decreased from 49 to 3 mmHg (p <0.001). There was a 350% increase in the mean diameter at the original coarctation site (3.8 to 13.8 mm, p <0.01). Although the maximal diameter varied from 8 to 18 mm, there was only a minor reduction in the length of the CP-stents used (max. 11%). The dilatation was successful in all patients and there were no complications during balloon dilatation or stent implantation. All patients were hypertensive prior to stent implantation, with three of them requiring antihypertensive drug therapy. In 2 patients only a moderate dilatation diameter was chosen initially due to the extremely small coarctation site (1 mm) and repeat dilatation after 12 months was performed in order to obtain a maximal aortic diameter. At a mean of 18 months of follow-up, 5 of 6 patients are normotensive. There is no recurrence of coarctation, aortic dissection or aneurysm formation and no stent displacement. These findings suggest that the implantation of CP-stents for coarctation of the aortamay cover a wide spectrum of aortic diameters and consequently hereby offer an effective alternative approach to surgery or ballon dilatation alone even in infancy and childhood. The potential for redilatation of CP-stents in a wide range of diameters without significant shortening adds to the benefit of this device in growing children.