Use of the Amplatzer muscular ventricular septal defect occluder for closure of perimembranous ventricular septal defects

Finite Element Analysis and Bench Testing of Ventricular Septal Defect Occluder

Complications after transcatheter closure of the ventricular septal defect (VSD) is significantly associated with the mechanical behaviour of the VSD occluder. This study aims to investigate the effect of structural parameters of the VSD occluder. A mechanical model of the VSD occluder was constructed by theoretical modelling. The mechanical properties of the VSD occluders with different braiding angles (30°, 45°, 60°), materials (nitinol (NiTi), polydioxanone (PDO)) and waist-heights (3 mm, 4 mm) were analysed and validated by bench tests. For the 30°NiTi, 45°NiTi, 60°NiTi and 45°PDO occluders, the bending angles at the waist under 1 mm radial shrinkage were 112°, 121°, 155° and 155°, respectively. And the maximum principal strains at the waist were 16.62%, 8.19%, 1.20%, and 0.66%, respectively. The maximum radial deformations with 0.5 rad axial bending at the waist were 1.73, 1.44, 0.41 and 1.68 mm, respectively. When the occluders were implanted into VSD with the mean thickness of 3.5 mm, high stress appeared at the margin and the contact area, and the area with the 3-mm-occluder was much larger. In conclusion, the 60°NiTi occluder showed better ability to fit the deformation of the defect than the other NiTi occluders, and the 45°PDO occluder performed better under compression conditions but poorly under bending conditions than the 45°NiTi occluder. The choice of the appropriate waist-height is beneficial to eliminate associative complication by reducing the contact stress.

Hybrid Subxiphoid Perventricular Approach as an Alternative Access in Neonates and Small Children Undergoing Complex Congenital Heart Interventions

The hybrid subxiphoid perventricular approach provides direct access through the heart and may alleviate the technical limitations of complex percutaneous interventions particularly in infants with low body weight. We present the outcomes from a tertiary cardiology center using this approach. We performed a retrospective review of all patients less than 15 kg who underwent a hybrid perventricular approach via a small subxiphoid incision. Medical records were reviewed to obtain clinical, demographic and outcome data. Seventeen patients underwent 18 hybrid perventricular procedures using a subxiphoid approach. Median age at time of procedure was 4.6 months (IQR = 1.6 to 18 months) and median weight was 6.2 kgs (IQR = 3.4 to 8.6 kgs). Six patients underwent hybrid pulmonary valve replacement (PVR), 5 patients underwent pulmonary outflow stenting, and 5 infants underwent hybrid ventricular septal defect (VSD) device closure. One patient with a single ventricle who did not tolerate a percutaneous approach underwent left pulmonary artery (LPA) stenting for severe LPA coarctation with subsequent right ventricular outflow tract (RVOT) stenting. One further patient underwent implantation of a larger diameter stent for pulmonary artery bifurcation stenosis. Procedure success rate was 89% with two of the VSD cases reverted to open surgical repair. There were no intra-procedural complications; however, one patient died within 72 h. Minor adverse events occurred in 2 patients including a wound infection in one patient with an immunodeficiency syndrome. Hybrid subxiphoid perventricular approach provides an excellent alternative access to the heart especially in low birth weight infants to prevent hemodynamic instability or in small children requiring large delivery sheaths.

The Efficacy and Medium to Long-Term Follow-Up of Transcatheter Retrograde Closure of Perimembranous Ventricular Septal Defects via the Femoral Artery With Amplatzer Duct Occluder II in Children

Objective: The aim of this study was to assess the efficacy and safety of transcatheter retrograde closure of perimembranous ventricular septal defect (pmVSD) via the femoral artery with an Amplatzer Duct Occluder II (ADO II) in children. Methods: The clinical and follow-up data of 102 children who had successfully undergone transcatheter retrograde closure of pmVSD via the femoral artery with Amplatzer Duct Occluder II (ADO II) from February 2012 to June 2019 in our center were retrospectively reviewed. Results: In 102 of 103 patients, the defects were successfully closed (99.0%). The average age was 4.03 ± 1.84 years and the mean weight was 17.50 ± 5.58 kg. The mean diameter of the defects was 2.58 ± 0.63 mm. Hundred of the occluders had a waist length of 4 mm. The complete closure rate was 89.2% 24 h after the procedure and 98% at the last follow-up. The follow-up period ranged from 6 to 92 months, with a median of 36 months. One child developed new mild aortic regurgitation (AR), and 9 patients developed new mild tricuspid regurgitation (TR). During follow-up, TR disappeared in 5 patients and decreased in 4 patients, and AR relieved in one patient. One patient developed intermittent complete left bundle branch block 4 days after the procedure and recovered sinus rhythm 2 days later. No serious complications occurred. Conclusion: Transcatheter retrograde closure of pmVSD via the femoral artery with ADO II in children is safe, feasible, and effective in selected patients.

Transcatheter device closure of ventricular septal defects in children: a retrospective study at a single cardiac center

BACKGROUND

Ventricular septal defect (VSD) is the most common congenital heart disease in the pediatric population. Nowadays, trans-catheter closure is considered a feasible method of therapy for most muscular and some perimembranous types of VSDs.

OBJECTIVE

Assess the safety, efficacy and outcome of percutaneous transcatheter closure of VSDs in children.

DESIGN

Retrospective, single center study.

SETTING

Madinah Cardiac Center, Madinah, Saudi Arabia.

PATIENTS AND METHODS

The study included all consecutive children who underwent transcatheter closure of isolated VSD during the period from December 2014 to January 2019. The data were collected from hospital database medical records. Transthoracic echocardiography (TTE) and an electrocardiogram (ECG) were done before and after the procedure in all the patients. The device was implanted by the retrograde or antegrade approach. All patients were subjected to follow-up evaluation at 1, 3, 6, 12 months, and annually thereafter with TTE and ECG.

MAIN OUTCOME MEASURES

Procedure success rate, clinical follow-up, TTE.

SAMPLE SIZE

70 children.

RESULTS

The mean (standard deviation) age of patients was 10.2 (4.1) years (range: 2-18 years), and their mean body weight was 30.9 (13.9) kg (range: 7.0-57.7 kg). Forty-eight (68.6%) children had muscular VSD (mVSD), and 22 (31.4%) children had perimembranous VSD (pmVSD). The majority of defects were closed via the retrograde approach using the Amplatzer muscular occluder device. At 24 hours after the procedure, the success rate was 90%. Only four (5.7%) cases had major adverse events including complete atrioventricular block, hemolysis, and thrombus formation.

CONCLUSION

Transcatheter closure is a safe and feasible procedure in VSDs of various morphologies, with a low adverse event rate.

LIMITATIONS

Retrospective design, single-center study, absence of control group.

CONFLICT OF INTEREST

None.

Interventional Cardiology for Congenital Heart Disease

Congenital heart interventions are now replacing surgical palliation and correction in an evolving number of congenital heart defects. Right ventricular outflow tract and ductus arteriosus stenting have demonstrated favorable outcomes compared to surgical systemic to pulmonary artery shunting, and it is likely surgical pulmonary valve replacement will become an uncommon procedure within the next decade, mirroring current practices in the treatment of atrial septal defects. Challenges remain, including the lack of device design focused on smaller infants and the inevitable consequences of somatic growth. Increasing parental and physician expectancy has inevitably lead to higher risk interventions on smaller infants and appreciation of the consequences of these interventions on departmental outcome data needs to be considered. Registry data evaluating congenital heart interventions remain less robust than surgical registries, leading to a lack of insight into the longer-term consequences of our interventions. Increasing collaboration with surgical colleagues has not been met with necessary development of dedicated equipment for hybrid interventions aimed at minimizing the longer-term consequences of scar to the heart. Therefore, great challenges remain to ensure children and adults with congenital heart disease continue to benefit from an exponential growth in minimally invasive interventions and technology. This can only be achieved through a concerted collaborative approach from physicians, industry, academia and regulatory bodies supporting great innovators to continue the philosophy of thinking beyond the limits that has been the foundation of our specialty for the past 50 years.

Current Status and Future Potential of Transcatheter Interventions in Congenital Heart Disease

Percutaneous therapies for congenital heart disease have evolved rapidly in the past 3 decades. This has occurred despite limited investment from industry and support from regulatory bodies resulting in a lack of specific device development. Indeed, many devices remain off-label with a best-fit approach often required, spurning an innovative culture within the subspecialty, which had arguably laid the foundation for many of the current and evolving structural heart interventions. Challenges remain, not least encouraging device design focused on smaller infants and the inevitable consequences of somatic growth. Data collection tools are emerging but remain behind adult cardiology and cardiac surgery and leading to partial blindness as to the longer-term consequences of our interventions. Tail coating on the back of developments in other fields of adult intervention will soon fail to meet the expanding needs for more precise interventions and biological materials. Increasing collaboration with surgical colleagues will require development of dedicated equipment for hybrid interventions aimed at minimizing the longer-term consequences of scar to the heart. Therefore, great challenges remain to ensure that children and adults with congenital heart disease continue to benefit from an exponential growth in minimally invasive interventions and technology. This can only be achieved through a concerted collaborative approach from physicians, industry, academia, and regulatory bodies supporting great innovators to continue the philosophy of thinking beyond the limits that has been the foundation of our specialty for the past 50 years.

Transcatheter closure of perimembranous ventricular septal defects with the Amplatzer Vascular Plug-II

OBJECTIVE

The aim of this study was to evaluate the safety and efficacy of the Amplatzer Vascular Plug-II used for the closure of perimembranous ventricular septal defects.

BACKGROUND

There are no FDA-approved transcatheter devices for the closure of perimembranous ventricular septal defects. Several studies have reported on the use of various devices either off-label or under clinical trial protocols. However these reports have described significant adverse events including residual shunts, complete heart block, arrhythmia, and new valve regurgitations. Thus far, no study on the Amplatzer Vascular Plug-II has been reported.

METHODS

We conducted a 4-year retrospective chart review from August, 2010 to August, 2014, of patients with perimembranous ventricular septal defects associated with ventricular septal aneurysm who underwent transcatheter closure using the Amplatzer Vascular Plug-II.

RESULTS

A total of 16 patients underwent Amplatzer Vascular Plug-II transcatheter closure of their perimembranous ventricular septal defects. The median age was 2.56 years (range: 0.5-27.3). Their median weight was 13.0 kg (range: 6.9-71.6). The left ventricular median defect size was 9.3 mm (range: 5.9-14.4). The right ventricular median defect size was 3.6 mm (range: 2.3-5.8). All the patients underwent successful device implantation with 83% of the patients having complete echocardiographic closure at the 1-year follow-up; however, one procedure was complicated by early device embolisation. The device was successfully retrieved and replaced with a larger device. There were no device-related outflow tract obstructions, rhythm abnormalities, or haemolysis.

CONCLUSION

Application of the Amplatzer Vascular Plug-II for closure of perimembranous ventricular septal defects appears to be a safe and effective treatment option. Prospective clinical trials and longer follow-up periods are warranted.

Medium to long-term echo follow-up after ventricular septal defect device closure

OBJECTIVE

We aimed to assess the medium to long-term results of echocardiographic follow-up of perimembranous and muscular ventricular septal defect closure with various Amplatzer devices.

METHODS

We successfully closed ventricular septal defects percutaneously in 45/49 patients. There were 35 perimembranous and 10 muscular ventricular septal defects. The median age and weight was 8.50 years (range 2-36.70 years) and 24 kg (range 10-106 kg), respectively. The median size of the ventricular septal defect was 7 mm (range 3-14 mm) on transthoracic echocardiography, 6 mm (range 4-15 mm) on transesophageal echocardiography, and 6 mm (range 3-14 mm) on left ventricular angiography. The median pulmonary-to-systemic blood flow ratio was 1.40 (range 1.0-3.0).

RESULTS

In the 49 attempted cases, the procedure was successful in 45, with a success rate of 91.84%. At a mean follow-up of 54.50 months, echocardiography showed complete closure in 41 (91%) patients and 4 (9%) had a tiny (1-2 mm) residual defect. New-onset aortic regurgitation was seen in 6 (13.3%) patients at 54.50 months, but it was mild in nature. Tricuspid valve regurgitation was observed in 13 (29%) patients at 54.50 follow-up, of whom 10 (22%) had mild and 3 (7%) had moderate regurgitation.

CONCLUSION

Transcatheter closure of perimembranous and muscular ventricular septal defects is effective, however, these patients need to be followed up regularly to detect device-related problems, specifically, aortic and tricuspid valve regurgitation.

Transcatheter Closure of Membranous Ventricular Septal Defects-Old Problems and New Solutions

Isolated perimembranous ventricular septal defect (VSD) is the most common congenital heart defect (after bicuspid aortic valve). Surgery is considered the gold standard for the treatment of these VSDs. However, it is associated with morbidity and mortality. Less invasive techniques have been developed, and percutaneous closure of perimembranous VSDs is now considered a possible alternative to the standard surgical approach. The main problem associated with transcatheter closure of VSD is the occurrence of complete atrioventricular block and need for pacemaker implantation. Improvements in technology and design will help to reduce the occurrence of this problem in the near future.

Transcatheter device closure of perimembranous ventricular septal defects: mid-term outcomes

Aims

The aim of this study was to evaluate the safety and efficacy of transcatheter closure for perimembranous ventricular septal defect (pmVSD) and its long-term results. The most common congenital heart condition is pmVSD. Transcatheter closure of pmVSD is a recently described technique with limited results for mid- to long-term follow-up.

Methods and results

Between June 2002 and June 2008, 848 patients with pmVSD were enrolled in our study and treated percutaneously with pmVSD occluders. All patients were followed up until December 2008, an average of 37 months. According to colour Doppler transthoracic echocardiography before the intervention and ventriculography, the average end-diastolic pmVSD size was 5.1 and 5.4 mm, respectively. Placement of the device was successful in 832 patients (98.1%) and the median device size was 8.6 mm. During follow-up, 103 adverse events (12.4%) were reported. Most adverse events were categorized as minor and there were nine major adverse events (8.7%), including two complete atrioventricular block requiring pacemaker implantation. Kaplan–Meier estimates showed >85% freedom from major or minor adverse events during a maximal follow-up of 79 months.

Conclusions

In experienced hands, transcatheter pmVSD closure can be performed safely and successfully with low morbidity and mortality. Long-term prognostic results are favourable, and the transcatheter approach provides a less-invasive alternative that may become the first choice in selected pmVSD patients.

This trial is registered with ClinicalTrials.gov, number NCT00890799.

Transcatheter closure of perimembranous ventricular septal defect: is the risk of heart block too high a price?

The late development of heart block in paediatric patients following device closure of a perimembranous ventricular septal defect may be a cause for concern.