Congenital heart disease: addressing the need for novel lower-risk percutaneous interventional strategies.

INTRODUCTION: With the advent of improved neonatal care, increasingly vulnerable higher-risk patients with complex congenital heart anomalies are presenting for intervention. This group of patients will always have a higher risk of an adverse event during a procedure but by recognizing this risk and with the introduction of risk scoring systems and thus the development of novel lower risk procedures, the rate of adverse events can be reduced. AREA COVERED: This article reviews risk scoring systems for congenital catheterization and demonstrates how they can be used to reduce the rate of adverse events. Then, novel low risk strategies are discussed for low-weight infants e.g. patent ductus arteriosus (PDA) stent insertion; premature infants e.g. PDA device closure; and transcatheter pulmonary valve replacement. Finally, how risk is assessed and managed within the inherent bias of an institution is discussed. EXPERT OPINION: There has been a remarkable improvement in the rate of adverse events in congenital cardiac interventions, but now, as the benchmark of mortality rate is switched to morbidity and quality of life, continued innovation into lower risk strategies and understanding the inherent bias when assessing risk will be key to continuing this improvement.

Left atrial appendage closure: outcomes and challenges.

Whereas the left atrial appendage plays a rather minor role under physiological circumstances, it gains an importance in patients with atrial fibrillation. Compelling evidence has revealed that the left atrial appendage is implicated as the source of thrombus in the vast majority of strokes in atrial fibrillation. Oral anticoagulation remains the standard of care for stroke prevention in atrial fibrillation; nevertheless, this treatment has several limitations and is often contraindicated, particularly in the elderly population in whom the risk of stroke is high. Therefore, occluding the left atrial appendage is a logical approach to prevent thrombus formation and subsequent cardioembolic events in these patients. We present a review of clinical outcomes of patients with atrial fibrillation undergoing left atrial appendage closure and the challenges faced in this field.

Indications, techniques and results of percutaneous patent foramen ovale closure.

Patent foramen ovale (PFO) has been shown to be more prevalent in certain disease states, suggesting a potentially causative role in some patients with cryptogenic stroke, migraine headache or a number of other conditions. Percutaneous PFO closure has become a reasonable treatment option in a subset of those patients. Our objective is to review the possible indications of PFO closure. We further elucidate the technical aspects of PFO closure, provide an overview of the available devices and summarize results of PFO closure procedures.

Evaluation of the AMPLATZER vascular plug for embolization of peripheral vascular malformations associated with congenital heart disease.

OBJECTIVE: The purpose of this study is to evaluate the recently FDA-approved AMPLATZER Vascular Plug in the embolization of vascular lesions associated with congenital heart disease (CHD). BACKGROUND: Fistulas and arteriovenous malformations have been occluded using various devices. The AMPLATZER Vascular Plug is a self-expandable, cylindrical device, used for embolization in the peripheral vasculature. METHODS: A total of 84 vessels in 52 patients with CHD from 11 centers were occluded with 89 AMPLATZER Vascular Plugs, delivered through a coronary guide catheter in various vascular sites, including collaterals, pulmonary arterio-venous and coronary artery fistulas, transhepatic tracts, central shunts, patent ductus arteriosus (PDA), and excluded hepatic vein. Complete vessel occlusion was demonstrated within 10 min in 94% of patients. RESULTS: There was no device embolization, vascular disruption, or procedure-related complication. One vascular plug implanted in a large type C PDA required surgical removal followed by PDA ligation, after 5 weeks from successful implant because of significant residual flow through the device. CONCLUSIONS: The AMPLATZER Vascular Plug is an effective transcatheter occlusion device in the embolization of a wide variety of vascular lesions associated with CHD. Based on our early experience, caution should be used when considering the Vascular Plug as a closure device for large PDA.

Hybrid pediatric cardiac surgery.

Minimally invasive strategies can be expanded by combining standard surgical and interventional techniques. We performed a longitudinal prospective study of all pediatric patients who have undergone hybrid cardiac surgery at the University of Chicago Children's Hospital. Hybrid cardiac surgery was defined as combined catheter-based and surgical interventions in either one setting or in a planned sequential fashion within 24 hours. Between June 2000 and June 2003, 25 patients were treated with hybrid approaches. Seventeen patients with muscular ventricular septal defects (mVSDs) (mean age, 4 months; range, 2 weeks-4 years) underwent either sequential Amplatzer device closure in the catheterization laboratory followed by surgical completion (group 1A, n = 9) or one-stage intraoperative off-pump device closure (group IB, n = 8) with subsequent repair of any concomitant heart lesions. Eight patients with branch pulmonary artery (PA) stenoses (group 2) underwent intraoperative PA stenting or stent balloon dilatation along with concomitant surgical procedures. All patients survived hospitalization. Complications from the hybrid approach were mostly confined to groups 1A and 2. At a mean follow-up of 18 months, 2 group 1A patients died suddenly several months after discharge. All other patients are doing well. Hybrid pediatric cardiac surgery performed in tandem by surgeons and cardiologists is safe and effective in reducing or eliminating cardiopulmonary bypass. Patients with mVSDs who are small, have poor vascular access, or have concomitant cardiac lesions are currently treated in one setting with the perventricular approach.

Multicenter experience with perventricular device closure of muscular ventricular septal defects.

Hybrid procedures are becoming increasingly important, especially in the management of congenital heart lesions for which there are no ideal surgical or interventional options. This report describes a multicenter experience with perventricular muscular venticular septal defect (VSD) device closure. Three groups of patients (n = 12) were identified: infants with isolated muscular VSDs (n = 2), neonates with aortic coarctation and muscular VSDs (n = 3) or patients with muscular VSDs and other complex cardiac lesions (n = 2), and patients with muscular VSDs and pulmonary artery bands (n = 5). Via a sternotomy or a subxyphoid approach, the right ventricle (RV) free wall was punctured under transesophageal echocardiography guidance. A guidewire was introduced across the largest defect. A short delivery sheath was positioned in the left ventricle cavity. An Amplatzer muscular VSD occluding device was deployed across the VSD. Cardiopulmonary bypass was needed only for repair of concomitant lesions, such as double-outlet right ventricle, aortic coarctation, or pulmonary artery band removal. No complications were encountered using this technique. Discharge echocardiograms showed either mild or no significant shunting across the ventricular septum. At a median follow-up of 12 months, all patients were asymptomatic and 2 patients had mild residual ventricular level shunts. Perventricular closure of muscular VSDs is safe and effective for a variety of patients with muscular VSDs.

Successful combined orthotopic liver transplant and transcatheter management of atrial septal defect, patent ductus arteriosus, and peripheral pulmonic stenosis in a small infant with Alagille syndrome.

We report on a 4-kg infant with Alagille syndrome and congenital heart disease consisting of atrial septal defect (ASD), patent ductus arteriosus (PDA), and severe peripheral pulmonic stenosis. He underwent successful orthotopic liver transplant along with catheter closure of the ASD and PDA using the Amplatzer device and placement of Palmaz stents in both pulmonary arteries.

Immediate and six-month results of the profile of the Amplatzer septal occluder as assessed by transesophageal echocardiography.

Catheter closure of secundum atrial septal defect (ASD) using the Amplatzer septal occluder (ASO) is a potential alternative for open surgical repair. However, the large profile of the device obtained immediately after closure continues to raise some concerns regarding its long-term safety. To evaluate the changes in the profile of the device after being deployed, transesophageal echocardiography was performed in 70 patients (17 men and 53 women) who underwent catheter closure of ASDs immediately after and at 6-month follow-up. The median age at closure was 16 years (range 1.9 to 75) and the median size of the ASD as assessed by transesophageal echocardiography was 14 mm (range 3 to 25). The thickness (profile) of the device was assessed in the 4-chamber, short- and long-axis views of the interatrial septum, and measured at its middle and at the junction of the waist with the disc at its 2 ends. Seventy-three devices were deployed in the 70 patients. The median size of the device was 19 mm (range 8 to 34). Complete closure was achieved in 81.4% and 91.4% immediately after and at 6-months follow-up, respectively. The thickness of the device at its middle decreased from 12.2 +/- 4.3, 12.2 +/- 3.7, and 12.5 +/- 4.3 mm in the 4-chamber, short- and long-axis views to 6.5 +/- 2.0, 6.3 +/- 1.9, and 6.5 +/- 2.2 mm, respectively. The thickness of the device at its superior, inferior, anterior, and posterior edges also decreased by 41.8% +/- 14.0% to 43.7% +/- 9.8%. The changes in the thickness were related to device size. Larger devices were thicker after being deployed. We conclude that the thickness of the ASO decreases by 42% to 48% within 6 months after deployment, resulting in a lower profile.

Simultaneous transcatheter occlusion of two atrial baffle leaks and stent implantation for SVC obstruction in a patient after Mustard repair.

A 19.5-year-old patient after Mustard operation was found to have baffle leaks and obstruction. This patient underwent successful device closure of the leaks using the Amplatzer device and stent implantation with complete resolution of the symptoms. Cathet Cardiovasc Intervent 2001;54:72-76.

Pediatric interventional cardiology: the cardiologist's role and relationship with pediatric cardiothoracic surgery.

The advances in pediatric interventional cardiac catheterization have changed the therapeutic strategy for many patients with CHD. The procedure of choice for valvar stenosis, recoarctation, collateral vessel occlusion, and branch PA stenosis has moved from the operating room to the catheterization laboratory. Effective and safe transcatheter interventions now exist for closure of ASDs, VSDs, and PDAs and are considered viable alternatives to surgical closure. Other interventional catheterization procedures are currently being investigated to complement the surgical management of patients with complex anatomy, including covered stents for repair of aortic aneurysms, covered stents to complete the Fontan circulation in patients after a modified Glenn shunt, multiple stent designs for all vascular stenoses, percutaneous PA band, and transcatheter resurrection of the pulmonary valve in patients with severe pulmonary regurgitation. The rapid advances in the technology used in the catheterization laboratory will serve to improve the care we provide for our patients and extend the range of interventions performed outside of the operating room. Pediatric cardiologists and congenital heart surgeons must understand each other's interventional techniques and how they can be used in a coordinated fashion. This may involve staged therapy with transcatheter intervention before surgery, transcatheter interventions in the operating room, or modifications of surgical techniques to facilitate future interventional catheterization completion of a staged repair of complex disease. This interaction is essential for the optimal management of our patients with both straightforward lesions and complex anatomy.

Balloon angioplasty of native coarctation of the aorta in infants and neonates: is it worth the hassle?

Balloon angioplasty (BA) for native coarctation of the aorta (CA) in infants and neonates remains controversial with a high incidence of restenosis. The purpose of this study is to analyze our acute and midterm results for BA of native CA in infants and neonates and try to identify factors that may be predictive of outcome. Between September 1991 and June 1999, 17 patients with CA underwent BA at a median age of 3 months (range 2 weeks--9 months) and median weight of 4.8 kg (range 2.8--7 kg). Fourteen patients had discrete CA and 3 had tubular hypoplasia. All patients were hemodynamically stable prior to BA and no patients had critical coarctation requiring prostaglandin E(1) infusion to maintain ductus arteriosus patency. Seven patients had other associated cardiac defects. All patients had significant initial improvement. The mean peak systolic gradient across the CA improved from 43 +/- 15 mmHg to 10 +/- 8 mmHg (p < 0.001), and the mean minimum diameter of the aortic lumen increased from 2.4 +/- 0.9 mm to 5.2 +/- 1.0 mm (p < 0.001). There was no mortality or major complication. At median follow-up interval of 2.7 years (0.15-7.75 years), 10 (59%) of 17 patients are clinically well and have an upper to lower limb systolic blood pressure difference of <20 mmHg. Seven (41%) of 17 patients developed significant restenosis (5 of these patients underwent repeat BA, which was successful in 3 patients). Four (24%) patients underwent surgical repair at a median age of 4.5 months (3--6.9 months) and a median time interval of 4 months (2--6.5 months) from the initial BA. All 3 patients with tubular hypoplasia type of CA underwent surgical repair. No patients developed aortic aneurysm following initial or repeat BA. All patients who underwent surgical repair were 1 month or less in age at the time of their initial BA. We conclude that BA of native CA in infants and neonates can be performed safely with low mortality and morbidity. It appears to offer the best results in patients who are older than 1 month with discrete CA and a well-developed aortic arch. Further restenosis of the discrete CA can be managed successfully by repeat BA.

Patent ductus arteriosus equipment and technique. Amplatzer duct occluder: intermediate-term follow-up and technical considerations.

Between May 1997 and June 2000, 69 patients, ages 0.1 to 34 years, underwent attempted anterograde transcatheter closure of a patent ductus arteriosus (PDA) using the Amplatzer Duct Occluder (ADO). The ADO is a cone-shaped, self-centering, and repositionable occluder made of nitinol wire mesh. A 5Fr to 7Fr sheath was used for the delivery of the device. The mean PDA diameter (at the pulmonary end) was 4.6 +/- 1.9 mm (range 1 mm-8.5 mm). Sixty-seven of the 69 patients had successful device placement. The mean ADO smallest diameter was 6.9 +/- 1.8 mm (range 4 mm-12 mm). Complete angiographic closure occurred in 62 (92.5%) of 67 patients (95% confidence interval, 88.22%-98.77%). In five patients, there was a trivial residual shunt immediately after the procedure. At 24 hours, color Doppler flow imaging revealed complete closure in all 67 (100%) patients. The unsuccessful attempts occurred in two patients with a small, 1-mm diameter native PDA and residual PDA after surgical occlusion. Fluoroscopy time was 7.6 +/- 1.8 minutes (4 min-18 min). No complications were observed. At a median follow-up of 1.5 years (range 0.25 to 3.2 years), all patients had complete closure without complications. We conclude that transcatheter closure using the ADO is a highly effective and safe treatment for most patients with PDA.

Early experience with the Amplatzer ductal occluder for closure of the persistently patent ductus arteriosus.

Using an Amplatzer duct occluder, 106 patients (weight 21 +/- 18 kg) underwent an attempt at catheter closure of a persistently patent ductus arteriosus (PDA). Their age ranged from 22 days to 48 years. The PDA measured between 1.2 to 8.1 mm at its narrowest diameter. The device was successfully implanted in 105 patients. The immediate closure rate was 70% and gradually increased to 100% at 1-month follow-up. There was no clinical evidence of hemolysis and no incidence of device embolization or bacterial arteritis. Doppler evaluation showed no evidence of aortic arch or pulmonary artery obstruction. The device, which is currently undergoing multicenter clinical trial in the United States, is proving to be a safe and effective device for closure of the persistently PDA.

Transcatheter closure of atrial septal defects in children & adults using the Amplatzer Septal Occluder.

We are reporting the worldwide experience in closing atrial septal defects (ASDs) in children and adults using the Amplatzer Septal Occluder (ASO) as of July 2000. The outcome measures were safety and efficacy with special emphasis on: (1) immediate success of the ASD closure as measured by transesophageal echocardiography (TEE), (2) short- and medium-term follow-up at 24 hours and 1 and 3 months and long-term follow-up at 1, 2, and 3 years as assessed by transthoracic echocardiography (TTE); and (3) the incidence of complications. In all, 3580 procedures were performed in 3535 patients. In 75 patients, the device was not implanted for variety of reasons; 3460 patients received a single ASO device and 45 received two devices for multiple ASDs. The median age of the patients was 12.1 year, (range, 10 days-88 years, the median weight was 41.0 kg (range, 2.4-137 kg) and the median Qp/Qs ratio was 2 (range, 0.3-10). The median size of ASD by TEE was 14 mm (range, 1-38 mm) and the median stretched diameter was 18 mm (range, 4-44 mm). The median size of device implanted was 18 mm (range, 4-40 mm). The median fluoroscopy time was 17.1 minutes (range, 0.0-194.0 minutes). The immediate success rate including those patients with complete closure, trivial residual shunt, or with small residual shunt was 97.4%. This increased to 99.2% and 100% at 3 months and 3 years, respectively. Minor complications were encountered in 2.8% of procedures, while serious complications occurred in less than 0.3% of the cases. There were no device related deaths. We conclude that the ASO is a safe and effective device for catheter closure of small to large ASDs up to a stretched diameter of 40 mm in children and adults with very high short-, medium, and long-term success rates.