Comparison of surgical, stent, and balloon angioplasty treatment of native coarctation of the aorta: an observational study by the CCISC (Congenital Cardiovascular Interventional Study Consortium)

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.

Coarctation of the aorta in adolescents and adults: A review of clinical features and CT imaging

Coarctation of the aorta (CoA), while usually identified and treated in the neonatal/infant period, is increasingly seen in adults, either primarily or (more often) following repair. Imaging plays a crucial role in the diagnosis, therapeutic planning, and follow-up of patients with CoA. Clinical management of CoA in adults optimally involves a multidisciplinary team; accordingly, imagers should be familiar with the underlying pathology, associations, and management of CoA in addition to imaging protocoling and interpretation. We will review the relevant clinical and imaging features of CoA, with an emphasis on patients beyond childhood.

Impact of Hospital Volume on Outcomes of Endovascular Stenting for Adult Aortic Coarctation

Use of transcatheter endovascular stenting has been increasing in the treatment of coarctation of aorta (CoA). The present study was undertaken on adults with CoA who underwent stent placement from 2000 to 2011 to analyze the relation of hospital volumes to the outcomes of stenting in adults with CoA. It was a retrospective study based on Healthcare Cost and Utilization Project's Nationwide Inpatient Sample (NIS) database from 2000 to 2011 and identified subjects using the International Classification of Diseases, Ninth Revision, Clinical Modification procedure code of 747.10 (CoA). Annual hospital volume was calculated using unique hospital identifiers. Weights provided by the Nationwide Inpatient Sample were used to generate national estimates. A total of 105 (weighted 521) subjects were identified with International Classification of Diseases, Ninth Revision, code of 39.90 (Endovascular stent). Hospital volumes were divided into tertiles. We compared the highest tertile (≥3 procedures annually) with other tertiles (<3 procedure annually). The composite outcomes of the analysis were procedure-related complications, length of stay (LOS), and cost in relation to the hospital volume. No inhospital death was reported in either group. Hospitals with ≥3 procedures annually had significantly lower incidence of complications (9.5% vs 23.0%) compared to the hospitals with <3 procedures annually (p-value 0.002). Similar results were obtained after multivariate regression analysis in relation to hospital volume. Shorter LOS and lower cost were observed with annual hospital volume of ≥3 procedures. In conclusion, stenting adults for CoA is remarkably safe, and the outcomes of the procedure have improved in centers with annual hospital volume of ≥3 procedures. There is also decreasing trend of procedure-related complications, shorter LOS, and lower costs compared to centers with annual volume <3 procedures.

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.

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.

Coarctation of the Aorta: Strategies for Improving Outcomes

Coarctation of the aorta is a common congenital heart defect through which management has rapidly evolved over the last few decades. The role of transcatheter-based therapies is expanding and seems to be an effective treatment option for coarctation, especially in adults. Patients with prior coarctation repair are at risk of long-term complications related to prior surgeries and associated congenital heart defects, in particular, the risk of restenosis and aortic aneurysm development related to the timing and mode of prior intervention. This article outlines the evaluation and management of adults with unrepaired coarctation and patients after coarctation repair.

Most Coarctations, Recoarctations, and Coarctation-Related Aneurysms Should Be Treated Endovascularly

For patients with coarctation of the aorta (CoA), surgical intervention results in an overall survival rate nearly twice that of medical management. Therefore, surgical correction of CoA has traditionally been warranted in the majority of patients, even though open repair entails its own complications. With the advent of endovascular technology, many interventionalists hoped that this approach would decrease the complications associated with open surgical repair of CoA. Nevertheless, there is still an ongoing debate about the merits of traditional open surgery versus endovascular therapy. In this review, we discuss the role of these two approaches for the management of CoA, recoarctation, and coarctation-related aneurysms.

Contemporary Results of Aortic Coarctation Repair Through Left Thoracotomy

BACKGROUND

Although surgical results for repair of coarctation of the aorta (CoA) have steadily improved, management of this condition remains controversial. The purposes of this study were to analyze the long-term outcomes of patients undergoing CoA repair through left thoracotomy and to define risk factors for reintervention.

METHODS

All patients who were less than 18 years old and who underwent initial repair of CoA through left thoracotomy from 1995 to 2013 at Texas Children's Hospital (Houston, TX) were included. Patients were classified into 3 groups: 143 (42%) neonates (0 to 30 days old), 122 (36%) infants (31 days to 1 year old), and 78 (23%) older children (1 to 18 years old). Univariate and multivariate analyses were performed.

RESULTS

A total of 343 patients (129 [38%] girls) with median age of 53 days (interquartile range [IQR],12 days to 9 months) and weight of 4.1 kg (IQR, 3.1 to 8.0) underwent repair with extended end-to-end anastomosis (291 patients [85%]), end-to-end anastomosis (44 patients [13%]), interposition graft (2 patients [0.6%]), or subclavian flap (6 patients [2%]). Concomitant diagnoses included genetic abnormalities (48 patients [14%]), isolated ventricular septal defects (58 patients [17%]), small left-sided structures (53 patients,16%), or other complex congenital heart disease (18 patients [5%]). Perioperative mortality was 1% (n = 4, all neonates). At a median follow-up of 6 years (7 days to 19 years), only 14 (4%) patients required reintervention (10 catheter-based procedures, 6 surgical repairs). A postoperative peak velocity of 2.5 m/s or greater was an independent risk factor for reintervention (odds ratio [OR], 4.0; 95% confidence interval [CI], 1.4 to 11.6). Within the cohort, 95 (33%) patients were hypertensive or remained on cardiac medications a median of 12 years (6 months to 19 years) after the surgical procedure. Development of perioperative hypertension was associated with higher risk of chronic hypertension or cardiac medication dependency (OR, 1.9; 95% CI, 1.1 to 3.3).

CONCLUSIONS

CoA repair through left thoracotomy is associated with low rates of morbidity, mortality, and reintervention. Aortic arch obstruction should be completely relieved at the time of surgical intervention to minimize the risk of long-term recoarctation.

Intermediate Outcomes in the Prospective, Multicenter Coarctation of the Aorta Stent Trial (COAST)

BACKGROUND

The Coarctation of the Aorta Stent Trial (COAST) was designed to assess the safety and efficacy of the Cheatham Platinum stent when used in children and adults with native or recurrent coarctation. Acute outcomes have been reported. We report here follow-up to 2 years.

METHODS AND RESULTS

A total of 105 patients underwent attempted implantation, with 104 successes. There were no procedural deaths, serious adverse events, or surgical intervention. All patients experienced immediate reduction in upper- to lower-extremity blood pressure difference with sustained improvement to 2 years. Rates of hypertension and medication use decreased from baseline to 12 months and remained largely unchanged at 2 years. Six aortic aneurysms have been identified: 5 were successfully treated with covered stent placement, and 1 resolved without intervention. Stent fractures were noted in 2 patients at 1 year and 11 patients at 2 years, with evidence of fracture progression. To date, only larger stent diameter was associated with stent fracture. Twelve additional fractures have occurred after 2 years. No fracture has resulted in loss of stent integrity, stent embolization, aortic wall injury, or reobstruction. Nine reinterventions occurred in the first 2 years for stent redilation and address of aneurysms, and 10 additional reinterventions occurred after 2 years.

CONCLUSIONS

The Cheatham Platinum stent is safe and associated with persistent relief of aortic obstruction. Stent fracture and progression of fracture occur but have not resulted in clinically important sequelae. Reintervention is common and related to early and late aortic wall injury and need for re-expansion of small-diameter stents.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00552812.

The First Ten of Everything: A Review of Past and Current Practice in Pediatric Cardiac Percutaneous Interventions

OBJECTIVES

This study was designed to compare outcomes of the most common pediatric cardiac interventions from the time of implementation with the current era.

BACKGROUND

Since the introduction of semilunar valve balloon dilation and device closure of the arterial duct and septal defects, development of interventional techniques and devices has been rapid. However, few studies have compared outcomes between those initial interventions and those in the current era.

METHODS

Five validated common catheter-based therapies were chosen for analysis, including atrial and duct device closure, balloon dilation of the aortic and pulmonary valves, and native coarctation of the aorta. A retrospective review of the first and most recent 10 consecutive patients in each group was performed.

RESULTS

There was a high mortality (30%) among neonates who underwent aortic valve (AV) dilation in the early era, but no mortality noted in other groups. In the early era, transcatheter atrial defect closure and AV dilations were associated with a low success rate (60% for both lesions) and a high complication rate (40% for atrial septal defect, 30% for AV dilations). Among the last 10 children, the atrial defect occlusion was successful in 100% without complications and AV dilations where successful in all children with a 30% complication rate (one major, two minor).

CONCLUSIONS

A learning curve with device development plays a significant role in the evolution of transcatheter techniques. These data provide baseline estimates of success and may be used as a template in the future when new techniques are adapted into practice.

A novel design biodegradable stent for use in congenital heart disease: mid-term results in rabbit descending aorta

OBJECTIVES

This study evaluates the feasibility of delivery and deployment of low and medium molecular weight (LMW and MMW, respectively) double-opposing helical (DH) poly-l-lactic acid biodegradable stent (BDS) in rabbit descending aorta (DAO). Secondary objectives were to assess patency and inflammation of stented vessels at 9 months and to investigate safety following intentional embolization of stent fragments in DAO.

BACKGROUND

A BDS that will relieve aortic obstruction and disappears as the child grows older allowing for preservation of aortic wall elasticity and natural growth of aorta will be ideal to treat Coarctation (CoA). BDS have never been evaluated in the DAO.

METHODS

Seven New Zealand white rabbits underwent implantation of DH-LMW (n = 7), DH-MMW (n = 3), and metal stents (n = 7) in DAO. BDS fragments were intentionally embolized into DAO in two rabbits.

RESULTS

All stents were deployed via a 6-French sheath. Five BDS covered the origin of major DAO side branches. Angiography and intravascular ultrasound showed good stent apposition to the wall of DAO with minimal luminal loss at 9 months follow-up. All stents had minimal neointimal hyperplasia on histopathology. Adverse events included 1 death, 1 aortic aneurysm, and lower extremity ulceration due to self-mutilation in an embolization rabbit.

CONCLUSIONS

Pilot study confirms the feasibility of delivery and deployment of up to 6-millimeter diameter DH BDS in rabbit DAO. Stent integrity with DH design was maintained at 9 months with minimal vessel inflammation. Potential morbidity due to embolized BD fragments cannot be ruled out and needs further evaluation.

Stents in paediatric and adult congenital interventional cardiac catheterization

A 'stent' is a tubular meshed endoprosthesis that has contributed to the development of interventional catheterization over the past 30 years. In congenital heart diseases, stents have offered new solutions to the treatment of congenital vessel stenosis or postsurgical lesions, to maintain or close shunt patency, and to allow transcatheter valve replacement. First, stents were made of bare metal. Then, stent frameworks evolved to achieve a better compromise between radial strength and flexibility. However, almost all stents used currently in children have not been approved for vascular lesions in children and are therefore used 'off-label'. Furthermore, the inability of stents to follow natural vessel growth still limits their use in low-weight children and infants. Recently, bioresorbable stents have been manufactured and may overcome this issue; they are made from materials that may dissolve or be absorbed in the body. In this review, we aim to describe the history of stent development, the technical characteristics of stents used currently, the clinical applications and results, and the latest technological developments and perspectives in paediatric and adult congenital cardiac catheterization.

Procedural Outcome and One Year Follow up of Patients Undergoing Endovascular Stenting for Coarctation of Aorta: A Single Center Study

INTRODUCTION

Coarctation of aorta is the fourth most common cardiac lesion requiring intervention. While surgery used to be the only treatment option, endovascular intervention is now considered the first option in simple coarctation lesions. Despite increased popularity, there are currently no FDA approved stents for use in coarctation of aorta and data on the outcome of this procedure is still sparse.

METHODS

Between October 2004 and June 2010, 33 patients who underwent treatment with Cheatham-Platinum stents for coarctation of aorta were retrospectively studied. All the patients underwent control CT scans at 6 month and echocardiography at 1 year follow-up.

RESULTS

There were 17 females and 16 males with a mean age of 26.64 ± 16.30 years (range 2-71 years). The mean stent length and balloon diameter were 3.18 ± 0.56 mm and 15.7 ± 3.12 mm respectively. We achieved an immediate success rate of 96.9% with the only complication of aortic rupture which led to our single mortality in this series. At 6 month follow up no complications were noted in the CT scans. The mean echocardiographic aortic arch gradient at one year follow up was 21.73 ± 11.06 mmHg.

CONCLUSION

This study is one of the few cohorts of patients with stenting for coarctation of aorta in Iranian population which comprised a diverse group of patients from early childhood to elderly. It was demonstrated in this study that stenting for coarctation of aorta is a safe and effective procedure if done carefully and performed in selected patients.

New-generation stent grafts for endovascular management of thoracic pseudoaneurysms after aortic coarctation repair

OBJECTIVE

Late thoracic aneurysms develop in 5% to 12% of patients having undergone open repair for coarctation of the aorta (CoA). We report our early results for thoracic endovascular aortic repair for pseudoaneurysms after CoA repair.

METHODS

From 2008 to 2013, data regarding demographics, aneurysm morphology, procedure, and follow-up were collected prospectively on all patients treated for pseudoaneurysms after CoA repair. Retrospective analysis of identified patients was then performed.

RESULTS

Thirteen patients (six men, seven women) were treated. Patients were a median age, 45 years (interquartile range (IQR), 39-56; range, 27-66 years, and the median time after CoA repair to aneurysm treatment was 34 years (IQR, 24-40 years). All patients had saccular pseudoaneurysms of the aortic arch, with a median aneurysm size of 4.1 cm (IQR, 3.4-5.1 cm). The left subclavian artery (LSCA) was involved in 10 patients and was occluded at presentation in three. Four patients had concurrent LSCA revascularization with carotid-subclavian bypass, one had aortic arch hybrid repair, and the LSCA was intentionally covered in two patients. Patients underwent thoracic endovascular aortic repair using the conformable TAG (6 of 13; W. L. Gore & Associates, Flagstaff, Ariz), Valiant device (4 of 13; Medtronic, Minneapolis, Minn), and a custom-made Relay endograft with LSCA scallop (4 of 13; Bolton Medical, Barcelona, Spain). Technical success was 100%, with satisfactory deployment of the stent grafts in all patients. There was no 30-day mortality, stroke, or paraplegia. Median follow-up was 15 months (IQR, 9-19 months; range, 1-67 months). Two type II endoleaks from an intercostal artery were managed conservatively, and one type Ib endoleak was treated successfully with distal stent extension.

CONCLUSIONS

In this cohort, new-generation stent grafts have good early clinical and radiologic outcomes, avoiding the need for redo open surgery. Management of the LSCA can be tailored to individual patients with new stent graft technology. Long-term follow-up of these patients is crucial to understanding whether endovascular management of this cohort is acceptable.

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.

A prospective observational multicenter study of balloon angioplasty for the treatment of native and recurrent coarctation of the aorta

OBJECTIVES

Balloon angioplasty (BA) is an important treatment option for coarctation of the aorta. The congenital cardiovascular interventional study consortium (CCISC) represents a multi-institutional and multi-national effort to prospectively investigate congenital cardiac interventions. A prospective observational analysis of the efficacy and safety of balloon aortic angioplasty was conducted.

METHODS

Data were collected prospectively from 36 CCISC sites from 2004 to 2012. One hundred and thirty patients underwent BA for native (n = 76) and recurrent (n = 54) coarctation. Acute, short-term, and intermediate outcomes are described for BA performed in the setting of native and recurrent coarctation of the aorta. Outcome measures included residual upper to lower extremity blood pressure gradient (ULG), use of antihypertensive medications, aortic wall injury, reobstruction, and need for reintervention.

RESULTS

There was no procedural mortality. Acutely in native and recurrent coarctation, BA achieved an ULG less than 15 mm Hg in 73-80% and to less than 10 mm Hg in 54-68% of patients, respectively. At intermediate follow-up, ULG further improved, particularly for those who underwent initial reintervention for recurrent coarctation. No significant differences in aortic wall complications were seen and intervention free survival was similar for both groups. Following angioplasty, there was no significant difference in aortic wall complications; however follow up integrated imaging decreased over time.

CONCLUSIONS

BA is a safe and effective treatment for coarctation of the aorta acutely and at intermediate term. Although aortic injury occurred in patients with both native and recurrent coarctation, at intermediate follow-up, aneurysm was noted more often in those with initial intervention for native coarctation.

Evolving trends in interventional cardiology: endovascular options for congenital disease in adults

As increasing numbers of patients with congenital heart disease enter adulthood, there is a growing need for minimally invasive percutaneous interventions, primarily to minimize the number of repeated surgeries required by these patients. The use of percutaneous devices is commonplace for the treatment of simple lesions, such as atrial septal defect, patent foramen ovale, patent duct arteriosus, and abnormal vascular connections. There is also substantial experience with device closure of membranous and muscular ventricular septal defects, as well as more complex shunts such as baffle leaks after atrial switch repair and ventricular pseudoaneurysms. An increasing use of covered stents has improved the safety of aortic coarctation, conduit, and branch pulmonary stenosis interventions. Percutaneous pulmonary valve implantation now has an established role in the setting of dysfunctional right ventricle-pulmonary artery conduits or failing bioprosthetic pulmonary valves. Many patients remain unsuitable for percutaneous pulmonary valve implantation because of large diameter "native" outflow tracts, however, various techniques have emerged and multiple devices are in development to provide solutions for these unique anatomic challenges. Hybrid approaches involving use of surgical and transcatheter techniques are increasingly common, serving to optimize efficacy and safety of certain procedures; they depend on a collaborative and collegial relationship between cardiac surgeons and interventionalists that is primarily patient-centred.

Materials and manufacturing technologies available for production of a pediatric bioabsorbable stent

Transcatheter treatment of children with congenital heart disease such as coarctation of the aorta and pulmonary artery stenosis currently involves the use of metal stents. While these provide good short term results, there are long term complications with their use. Children outgrow metal stents, obligating them to future transcatheter dilations and eventual surgical removal. A bioabsorbable stent, or a stent that goes away with time, would solve this problem. Bioabsorbable stents are being developed for use in coronary arteries, however these are too small for use in pediatric congenital heart disease. A bioabsorbable stent for use in pediatric congenital heart disease needs to be low profile, expandable to a diameter 8 mm, provide sufficient radial strength, and absorb quickly enough to allow vessel growth. Development of absorbable coronary stents has led to a great understanding of the available production techniques and materials such as bioabsorbable polymers and biocorrodable metals. Children with congenital heart disease will hopefully soon benefit from the current generation of bioabsorbable and biocorrodable materials and devices.

Covered stents in the management of native coarctation of the aorta--intermediate and long-term follow-up

OBJECTIVES

To evaluate the results of covered Cheatham-Platinum stent implantation in the management of native coarctation of the aorta and report intermediate and long-term follow-up.

BACKGROUND

Covered stents are being used increasingly in severe and complex coarctation of the aorta mainly to reduce risk of aortic wall complications. There is, however, limited data on the intermediate and long-term outcome.

PATIENTS AND METHODS

Fifty-six patients received 59 covered Cheatham-Platinum stents (January 2002-December 2011) at a single center-in 54 patients as primary treatment and in 2 as a rescue. Mean age was 22.25 ± 1.2 (11-56) years and mean weight 58.6 ± 2.1 (32-99) kg. Primary end points were reduction in systolic pressure gradient and an increase in coarctation segment diameter. Changes in antihypertensive medicines and complications were recorded on follow-up.

RESULTS

Mean coarctation segment diameter increased from 4.69 ± 0.20 to 15.1 ± 3.2 mm (P < 0.0001). The systolic gradient decreased from mean of 51.4 ± 3.4 to 4.6 ± 0.7 mm Hg (P < 0.0001). There was one death 3 days postprocedure due to cerebral anoxia. There was one dissection diagnosed 24-hr postprocedure. At a mean follow-up of 45.9 ± 3.9 (3-120) months, all stents were patent and in good position on computed tomography. Four (7.1%) patients underwent successful redilation. Antihypertensive medication was decreased or stopped in 37 (66%) patients.

CONCLUSIONS

Covered Cheetham-Platinum stents may be used effectively as therapy of choice in selected patients with severe coarctation of the aorta. Aortic wall complications occur even with covered stents. Covered stents provide a safe alternative to conventional stenting in the intermediate and long-term and can be redilated safely to keep pace with somatic growth.

Stenting Options for Coarctation of the Aorta

The narrowing of the lumen in coarctation of the aorta can be relieved with a high degree of immediate success by transcatheter methods. All methods are associated with immediate and longer-term complications, including dissection, aneurysm formation, and recoarctation. The introduction of the use of covered stents in aortic coarctation is encouraging because the material cover provides additional protection to the acutely disrupted aortic wall and can provide long-term protection of the dilated segment and the downstream area of poststenotic dilation. This review discusses the currently available options for stenting aortic coarctation.

Endovascular treatment of stenoses in a pediatric patient with incomplete aortic duplication, mesenteric ischemia, and renovascular hypertension

Variations in abdominal aortic anatomy may have significant implications in various surgical procedures. We report here a pediatric patient with symptoms of chronic mesenteric ischemia, labile hypertension, and lower extremity claudication. Angiography revealed a partially duplicated aorta with the anterior aorta containing the splanchnic and renal arteries and the posterior segment perfusing the lower extremities. She was successfully treated with balloon angioplasty of two focal stenoses and is normotensive without abdominal symptoms at 1-year follow-up. To our knowledge, this is the first report of a successful endovascular intervention in a partially duplicated aorta.

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.