New transcatheter techniques for creation or enlargement of atrial septal defects in infants with complex congenital heart disease

Intracardiac ultrasound-guided transseptal puncture in horses: Outcome, follow-up, and perioperative anticoagulant treatment

BACKGROUND

Cardiac catheterizations in horses are mainly performed in the right heart, as access to the left heart traditionally requires an arterial approach. Transseptal puncture (TSP) has been adapted for horses but data on follow-up and closure of the iatrogenic atrial septal defect (iASD) are lacking.

HYPOTHESIS/OBJECTIVES

To perform TSP and assess postoperative complications and iASD closure over a minimum of 4 weeks.

ANIMALS

Eleven healthy adult horses.

METHODS

Transseptal puncture was performed under general anesthesia. Serum cardiac troponin I concentrations were measured before and after puncture. Weekly, iASD closure was monitored using transthoracic and intracardiac echocardiography. Relationship between activated clotting time and anti-factor Xa activity during postoperative enoxaparin treatment was assessed in vitro and in vivo.

RESULTS

Transseptal puncture was successfully achieved in all horses within a median duration of 22 (range, 10-104) minutes. Balloon dilatation of the puncture site for sheath advancement was needed in 4 horses. Atrial arrhythmias occurred in 9/11 horses, including atrial premature depolarizations (N = 1), atrial tachycardia (N = 5), and fibrillation (N = 3). Serum cardiac troponin I concentrations increased after TSP, but remained under the reference value in 10/11 horses. Median time to iASD closure was 14 (1-35) days. Activated clotting time correlated with anti-factor Xa activity in vitro but not in vivo.

CONCLUSIONS AND CLINICAL IMPORTANCE

Transseptal puncture was successfully performed in all horses. The technique was safe and spontaneous iASD closure occurred in all horses. Clinical application of TSP will allow characterization and treatment of left-sided arrhythmias in horses.

Development of an atrial transseptal puncture procedure in horses to access the left heart: An ultrasound-guided jugular vein and transhepatic approach

BACKGROUND

Radiofrequency ablation has been successfully applied to treat right atrial arrhythmias in horses. Ablation of left-sided arrhythmias requires a retrograde transarterial approach which is complicated. In human medicine, the left atrium is accessed through transseptal puncture (TSP) of the fossa ovalis (FO) using a caudal approach via the femoral vein.

OBJECTIVES

To develop a zero fluoroscopy TSP technique for horses using a jugular vein (cranial) and transhepatic (caudal) approach.

STUDY DESIGN

In vivo experimental study.

METHODS

Transseptal puncture was performed in 18 horses admitted for euthanasia and donated for scientific research under general anaesthesia: using a jugular vein approach (10 horses), a transhepatic approach (2 horses) or both (6 horses). Radiofrequency energy was applied on a guidewire to perforate the FO and allow sheath advancement under intracardiac and transthoracic echocardiographic guidance. Puncture lesions were inspected post-mortem.

RESULTS

Transseptal puncture was successful in 17/18 horses, of which 15/16 jugular vein approaches and 5/8 transhepatic approaches. Failure was due to technical malfunction, inability to advance the guidewire toward the heart and inability to advance the sheath through the FO. Intracardiac echocardiography was essential to safely guide the puncture process. Atrial arrhythmias caused by the TSP occurred in 13/18 horses. Puncture lesions were found in the right atrium in the FO region, and left atrium ventral to pulmonary vein ostium III.

MAIN LIMITATIONS

Because in several horses two approaches were tested consecutively, it cannot be excluded that the second TSP was performed at the previous puncture site. Due to the developmental nature of the study the approaches were not randomised and did not allow comparison.

CONCLUSION

Transseptal puncture is feasible in horses using ultrasound guidance and allows for electrophysiological exploration of the left heart. Further studies are needed to evaluate post-operative follow-up.

Stent Implantation Across the Atrial Flow Regulator Device

The Atrial Flow Regulator (AFR) is a self-expandable double-disc device with a central fenestration, intended to maintain a calibrated communication across the interatrial septum. We reported for the first time a stent implantation across an AFR device in an adolescent born with complex congenital heart disease with duct-dependent systemic circulation and severe combined pulmonary hypertension.

Transcatheter Interventions for Neonates with Congenital Heart Disease: A Review

Newborns with congenital heart disease often require interventions linked to high morbidity and mortality rates. In the last few decades, many transcatheter interventions have become the first-line treatments for some critical conditions in the neonatal period. A catheter-based approach provides several advantages in terms of procedural time, length of hospitalization, repeatability and neurodevelopmental issues (usually related to cardiopulmonary bypass). The main transcatheter procedures will be reviewed, as they are now valid alternatives to conventional surgical management.

Is combined use of radiofrequency ablation and balloon dilation the future of interatrial communications?

INTRODUCTION

Personalized and stable interatrial communication is an important palliative therapy for patients with heart failure. However, this remains a technically challenging task.

AREAS COVERED

In the past decades, substantial advancements in atrial septostomy for the creation of controllable and durable interatrial communication have been made, and numerous novel devices and techniques are in various stages of development. In this review, we discuss the evolving indications for atrial septostomy, current approaches with or without device implantation, and indicators for optimal interatrial communication. The combined use of radiofrequency ablation and balloon dilation (CURB) is an individualized management approach based on underlying hemodynamics, which demonstrates unique advantages in creating a sufficient interatrial communication with satisfactory stability. The advantages and disadvantages of this implant-free procedure are analyzed and its clinical prospects are assessed.

EXPERT OPINION

With ready availability, high safety, and efficacy, CURB is a promising procedure for creating personalized and stable interatrial communication without device implantation. Further research is required to simplify the procedure, screen optimal reference parameters for personalized therapy, and evaluate the long-term outcome in a large population of patients.

Transcatheter Cardiac Interventions in the Newborn: JACC Focus Seminar

For neonates with critical congenital heart disease requiring intervention, transcatheter approaches for many conditions have been established over the past decades. These interventions may serve to stabilize or palliate to surgical next steps or effectively primarily treat the condition. Many transcatheter interventions have evidence-based records of effectiveness and safety, which have led to widespread acceptance as first-line therapies. Other techniques continue to innovatively push the envelope and challenge the optimal strategies for high-risk neonates with right ventricular outflow tract obstruction or ductal-dependent pulmonary blood flow. In this review, the most commonly performed neonatal transcatheter interventions will be described to illustrate the current state of the field and highlight areas of future opportunity.

Modified wire atrial septostomy with a reverse transseptal puncture in an infant: Case report

We report a modified technique of wire atrial septostomy (WAS) with a reverse transseptal puncture (TSP) in an infant case of pulmonary atresia with intact ventricular septum. A radiofrequency (RF) wire was advanced to the septum through a 4 Fr pigtail catheter hooked on the left side of atrial septum and RF energy was applied while advancing the wire across the septum. Following that reverse TSP, WAS was performed to cut the septal tissue using a 0.010 microwire and RF wire. The atrial septum defect (ASD) was enlarged to a size of 15 mm. WAS with a reverse TSP could be a useful and safe method to enlarge ASD in infants with congenital heart diseases.

Left heart decompression by atrial stenting during extracorporeal membrane oxygenation

Persistent severe left ventricular dysfunction during extracorporeal membrane oxygenation (ECMO) requires left heart decompression. We describe stenting of the atrial septum as an alternative emergency approach for left heart decompression during ECMO in addition to the already published surgical and transcatheter approaches.

Wire Atrial Septostomy: A New Technique to Create a Large Defect in a Thickened Atrial Septum

Both balloon atrial septostomy and static balloon dilation are often ineffective in creating a large atrial septal defect in patients with a thickened atrial septum. In such situations, blade atrial septostomy and atrial septal stenting are alternative treatments. We have devised and performed a new technique, called wire atrial septostomy, which uses a thin soft wire to create a large defect. The details of the procedure are presented.

Early catheterization after initiation of extracorporeal membrane oxygenation support in children is associated with improved survival

OBJECTIVES

The study evaluated the institutional experience with cardiac catheterization on extracorporeal membrane oxygenation (ECMO) support.

BACKGROUND

There is scant literature on the outcomes of catheterization on ECMO.

METHODS

A retrospective review was performed of all children who underwent catheterization on ECMO from 2003 to 2013. Patients were categorized as cardiomyopathy (CM) or congenital heart disease (CHD).

RESULTS

During the study period, 215 children were placed on cardiac ECMO. Of these, 29.8% underwent 75 catheterization procedures while on ECMO support. The median age of the cohort was 1.5 months (range 0 days -16.7 years) and the median weight was 3.9 kg (2.2-63.1 kg). CM patients constituted 18.8% of the cohort and all of them underwent atrial septoplasty (an atrial septal stent in 7/12 and balloon atrial septoplasty or septostomy in 5). The survival to hospital discharge rate was 83% and the transplant-free survival rate was 58.3%. CHD patients constituted 81.2% of the cohort. In this group, transcatheter interventions were performed in 40.4% and subsequent surgical interventions in 40.4%. Survival to hospital discharge rate was 34.6% and transplant free survival rate was 32.7%. Overall, 76.7% underwent transcatheter or surgical interventions. The major catheterization complication rate was 6.7%. The mean ECMO-to-catheterization time was 1.6 days for survivors and 3.5 days for non-survivors (P = 0.034). Survival to discharge was better for the CM group compared to the CHD group (P = 0.01). Among CHD, survival was better with transcatheter interventions compared to no interventions or surgical interventions (P < 0.001).

CONCLUSIONS

Cardiac catheterization and transcatheter interventions on ECMO can be performed with low rate of complications. Catheterization was associated with high rate of interventions. Better survival to hospital discharge was associated with transcatheter interventions, earlier performance of catheterization after ECMO and diagnosis of CM. © 2016 Wiley Periodicals, Inc.

Atrial septal stenting - How I do it?

A wide atrial communication is important to maintain hemodynamics in certain forms of congenital and acquired heart defects. In comparison to balloon septostomy or blade septostomy, atrial septal stenting provides a controlled, predictable, and long-lasting atrial communication. It often needs a prior Brockenbrough needle septal puncture to obtain a stable stent position. A stent deployed across a previously dilated and stretched oval foramen or tunnel form of oval foramen carries higher risk of embolization. This review provides technical tips to achieve a safe atrial septal stenting. Even though this is a “How to do it article,” an initial discussion about the indications for atrial septal stenting is vital as the resultant size of the atrial septal communication should be tailored for each indication.

Hypoplastic left heart syndrome - a review of supportive percutaneous treatment

Due to the complex anatomical and haemodynamic consequences of hypoplastic left heart syndrome (HLHS), patients with the condition require multistage surgical and supportive interventional treatment. Percutaneous interventions may be required between each stage of surgical palliation, sometimes simultaneously with surgery as hybrid interventions, or after completion of multistage treatment. Recent advances in the field of interventional cardiology, including new devices and techniques, have significantly contributed to improving results of multistage HLHS palliation. Knowledge of the potential interventional options as well as the limitation of percutaneous interventions will enable the creation of safe and effective treatment protocols in this highly challenging group of patients. In this comprehensive review we discuss the types, goals, and potential complications of transcatheter interventions in patients with HLHS.

A 10-year single-centre experience in percutaneous interventions for multi-stage treatment of hypoplastic left heart syndrome

OBJECTIVES

The purpose of this paper is to report our 10 years of experience of interventional treatment of patients with hypoplastic left heart syndrome and to focus on the frequency, type, and results of percutaneous interventions during all the stages of palliation, considering the different techniques, devices, and complications.

BACKGROUND

Constant progress in surgical treatment of congenital heart defects in the last decade has significantly improved the prognosis for children with hypoplastic left heart syndrome. However, morbidity and mortality remain relatively high. Modern interventional procedures complement or occasionally replace surgical treatment.

METHODS

Between January, 2001 and December, 2010, 161 percutaneous interventions were performed in 88 patients with hypoplastic left heart syndrome. Patients were divided into four groups: (a) before the first surgical treatment including hybrid approach, (b) after first-stage Norwood operation, (c) after second-stage bidirectional Glenn operation, and (d) after third-stage Fontan operation.

RESULTS

Percutaneous interventions resulted in statistically significant changes in pulmonary artery pressures, vessel diameters, and O2 saturation. Complications occurred in 4.3% of interventions and were related mainly to stent implantation in stenosed pulmonary arteries.

CONCLUSIONS

Percutaneous interventions may result in haemodynamic stability and reduction in the number of operations. They may result in significant changes in pulmonary artery pressures, vessel diameters, O2 saturation, with a low rate of complications, which are mainly related to stent implantation in the pulmonary arteries.

Current outcomes of hypoplastic left heart syndrome with restrictive atrial septum: a single-center experience

Advances in the management of hypoplastic left heart syndrome (HLHS) have resulted in improved survival. However, short and long-term mortality in patients with a restrictive atrial septum remains high. All neonates diagnosed with HLHS from 2003 to 2010 at our institution were evaluated. Patients who underwent atrial septostomy within the first 72 h conformed the restrictive atrial septum group (HLHS-RS). Patients with a non-restrictive communication (HLHS-NRS) formed the control group. Outcomes and survival status were determined from review of medical records. Of the 141 newborns diagnosed with HLHS, 20 (14 %) required intervention for a restrictive atrial septum. Procedural success was achieved in 17/20 (85 %) patients. Complications occurred in ten procedures, two of which were life threatening. No procedural deaths occurred. Overall median follow up was 35.5 months (0.4-104). Initial hospitalization survival was 16/20 (80 %) for the HLHS-RS group and 114/121(94 %) for the HLHS-NRS (p = 0.028). Twenty (14 %) patients were lost to follow up and 9 (6 %) underwent heart transplant. Overall survival was 10/16 (62 %) for HLHSRS patients and 77/95 (81 %) for HLHS-NRS (p = 0.1). Survival after initial discharge was 10/12 (83 %) for the HLHS-RS group and 77/88 (87 %) for the HLHS-NRS (p = 0.67). No predictors for HLHS-RS outcome were identified. Mortality at first-stage palliation in HLHS neonates with a restrictive atrial septum remains higher than in those with an unrestrictive communication. However, survival after initial hospital discharge is similar.

Results of Balloon Atrial Septostomy as Preparation for Surgical Correction in Transposition of Great Arteries

Balloon atrial septostomy (BAS) is a palliative procedure performed in the preoperative management of patients with transposition of great arteries (TGA), to improve the mixing of blood between the 2 systems. This report describes experience at the Clínica Cardiovascular Santa Maria in Medellin, Colombia. Between 2002 and 2010, 22 patients with TGA underwent BAS. Patient age at the time of the procedure was 21 days on average; 68% of patients were male. Average weight was 2.96 kg and interatrial gradient was between 4 and 12 mm Hg. The average systemic oxygen saturation at the beginning of the procedure was 60%, with a final saturation of 90%. Z5 atrioseptostomy balloons were used in 18 patients (81%), using Rashkind technique; Tyshak balloon catheters were used in 3 patients (13%) with the Shrivastava technique; and static high-pressure peripheral angioplasty balloons were used in 3 patients (13%). Two patients underwent BAS with 2 types of balloons. Although there were no complications clearly attributable to the procedure, 14% of patients had evidence of focal brain injury on the postoperative magnetic resonance image. Six patients died (27%), 5 of them because of postoperative complications and 1 because of infectious complications at another institution. All postoperative deaths occurred before 2006. The BAS is a safe technique for preoperative stabilization of patients with TGA.

Hybrid management of a large atrial septal defect and a patent ductus arteriosus in an infant with chronic lung disease

We report a case wherein a dysmorphic four-month-old infant (weighing 4.5 kgs) with an 8 mm atrial septal defect (ASD), a 1.5 mm patent ductus arteriosus (PDA), a 2 mm mid-muscular ventricular septal defect (VSD) associated with chronic lung disease, and severe pulmonary hypertension, was successfully managed using a hybrid approach, without the use of cardiopulmonary bypass (CPB). Through a median sternotomy, the PDA was ligated and the ASD was closed with a 9 mm Amplatzer septal occluder implanted through peratrial access. The VSD was left untouched. Serial echocardiograms showed complete closure of the ASD and PDA, with progressive normalization of the pulmonary artery (PA) pressures within three months. The child rapidly gained weight and was weaned from sildenafil and oxygen administration. After 12 months, the VSD closed spontaneously and the child remained well, with normal PA pressures. A hybrid approach without the use of CPB should be considered in the management of infants with congenital heart disease, associated with chronic lung disease and pulmonary hypertension.

Novel transatrial septoplasty technique for neonates with hypoplastic left heart syndrome and an intact or highly restrictive atrial septum

Two patients born with hypoplastic left heart syndrome and an intact or highly restrictive atrial septum requiring emergent intervention are presented. For both patients, rapid septoplasty was performed using a hybrid approach involving direct atrial puncture and transatrial cutting balloon dilation of the atrial septum. This technique facilitates safe and rapid procedural completion and minimizes the risk of procedural complications in this very-high-risk patient population.

Noninvasive creation of an atrial septal defect by histotripsy in a canine model

BACKGROUND

The primary objective of this study was to develop an image-guided, noninvasive procedure to create or enlarge an atrial septal defect for the treatment of neonates with hypoplastic left heart syndrome and an intact or restrictive atrial septum. Histotripsy is an innovative ultrasonic technique that produces nonthermal, mechanical tissue fractionation through the use of high-intensity ultrasound pulses. This article reports the pilot in vivo study to create an atrial septal defect through the use of extracardiac application of histotripsy in an open-chest canine model.

METHODS AND RESULTS

In 10 canines, the atrial septum was exposed to histotripsy by an ultrasound transducer positioned outside the heart. Ultrasound pulses of 6-microsecond duration at a peak negative pressure of 15 MPa and a pulse repetition frequency of 3.3 kHz were generated by a 1-MHz focused transducer. The procedure was guided and monitored by real-time ultrasound imaging. In 9 of 10 canines, an atrial septal defect was produced, and shunting across the atrial septum was visualized. Pathology of the hearts showed atrial septal defects with minimal damage to surrounding tissue. No damage was found on the epicardial surface of the heart or other structures.

CONCLUSIONS

Under real-time ultrasound guidance, atrial septal defects were successfully created with extracardiac histotripsy in a live canine model. Although further studies in an intact animal model are needed, these results provide promise of histotripsy becoming a valuable clinical tool.

[Update on pediatric cardiology and congenital heart disease]

The fields of pediatric cardiology and congenital heart disease have experienced considerable progress in the last few years, with advances in new diagnostic and therapeutic techniques that can be applied at all stages of life from the fetus to the adult. This article reviews scientific publications in a number of areas that appeared between August 2007 and September 2008. In developed countries, congenital heart disease is becoming increasingly prevalent in nonpediatric patients, including pregnant women. Actions aimed at preventing coronary heart disease must be started early in infancy and should involve the promotion of a healthy diet and lifestyle. Recent developments in echocardiography include the introduction of three-dimensional echocardiography and of new techniques such as two-dimensional speckle tracking imaging, which can be used for both anatomical and functional investigations in patients with complex heart disease, including a univentricular heart. Progress has also occurred in fetal cardiology, with new data on prognosis and prognostic factors and developments in intrauterine interventions, though indications for these interventions have still to be established. Heart transplantation has become a routine procedure, supplemented in some cases by circulatory support devices. In catheter interventions, new devices have become available for the closure of atrial or ventricular septal defects and patent ductus arteriosus as well as for percutaneous pulmonary valve implantation. Surgery is also advancing, in some cases with hybrid techniques, particularly for the treatment of hypoplastic left heart syndrome. The article ends with a review of publications on cardiomyopathy, myocarditis and the treatment of bacterial endocarditis.

Interventions complementing surgery as part of multistage treatment for hypoplastic left heart syndrome: one center's experience

BACKGROUND

Interventional procedures often are used as part of multistage treatment for hypoplastic left heart syndrome (HLHS). This study aimed to evaluate the efficacy of interventions in multistage treatment of HLHS.

METHODS AND RESULTS

Between 1999 and 2007, 78 interventions were performed for 58 children with HLHS at different stages of surgical treatment. Group 1, involving 30 interventions for 22 patients with postoperative pulmonary arterial stenosis, showed reduced pulmonary artery pressure and increased vessel diameter. Group 2, involving 15 interventions after the Norwood operation for 12 patients with aortic arch obstruction, showed success for 11 patients. Group 3, involving eight balloon angioplasties of narrowed Glenn anastomosis for seven patients, showed abolition of the pressure gradient between the superior vena cava and the right pulmonary artery. Group 4, involving eight interventional closures of a fenestration for eight patients after a Fontan operation, showed increased oxygen saturation for all eight patients. Group 5, involving seven interventions for six patients in whom venovenous collaterals were closed percutaneously, showed improved oxygen saturation. For Group 6, uncommon miscellaneous interventions were used to stabilize the patients' condition before the next surgical treatment.

CONCLUSIONS

Interventional procedures play an important role during multistage treatment of HLHS. They allow for a reduction in the number of operations or stabilization of the patients' condition before the next surgical treatment.

Interventional therapy for neonates with critical congenital heart disease

Transcatheter interventional therapies for children continue to evolve at a remarkable rate. Perhaps no where are these procedures more important than in the critically ill newborn. In this core curriculum review article several of the most commonly performed interventions performed in critically ill newborns are discussed with regards to technique and outcomes.

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.

Restrictive tunnel patent foramen ovale and left atrial hypertension in single-ventricle physiology: implications for stent placement across the atrial septum

Our objective is to describe our approach to the management of patients with single-ventricle physiology and restrictive tunnel patent foramen ovale (TPFO) with unfavorable atrial septal morphology. We describe a series of five patients with single-ventricle physiology and restrictive TPFO and our experience with radiofrequency perforation (RFP), static balloon atrial septostomy (BAS), and stent implantation to create an alternative pathway for left atrial decompression. Between July 4, 2006, and July 10, 2007, five patients with single-ventricle physiology and restrictive TPFO were brought to the cardiac catheterization laboratory for decompression of a hypertensive left atrium. Four of five patients underwent RFP followed by static BAS and stent implantation across the newly created atrial communication. One patient had a stent placed across an existing TPFO. Unfortunately, stable stent position was not achieved in this case, and the patient required open atrial septectomy. In patients with single-ventricle physiology and a restrictive TPFO associated with left atrial hypertension, stent placement across the existing defect can result in unstable stent position. Using a RFP wire to create a new defect in the septum primum allows stable stent deployment across the atrial septum and achieves left atrial decompression.