Stenting of native right ventricular outflow tract obstructions in symptomatic infants: histological work-up of explanted specimen.

BACKGROUND: Stenting of stenotic right ventricular outflow tract is a palliative measure for severely impaired small babies with Tetralogy of Fallot or similar pathologies. Little is known about the histopathological fate of the stents in the right ventricular outflow tract. METHODS: Eight samples of surgically removed right ventricular outflow tract stents were histologically analysed according to a predefined protocol. RESULTS: The most frequent diagnosis was Tetralogy of Fallot in four patients, pulmonary atresia with ventricular septal defect in two patients, double outlet right ventricle with pulmonary obstruction in one patient, and muscular obstruction of the right ventricular outflow tract in one patient with a syndromic disease with hypertrophic cardiomyopathy. Stents mean implantation duration was 444 days ranging from 105 to 1117 days (median 305.5 days). Histology revealed a variable degree of pseudointima formation consisting of fibromuscular cells surrounded by extracellular matrix. Four of the specimen contained adjacent myocardial tissue fragments, which showed regressive changes. Neither myocardium nor pseudointima tissue or tissue parts locally related to stent struts were infiltrated by inflammatory cells. CONCLUSIONS: Histological analysis after explantation of early-in-life implanted right ventricular outflow tract stents revealed predominantly pronounced neo-intimal proliferation with a visible endothelial layer, no signs of inflammation, and no prolapse of muscular tissue through the stent struts. Thus, implantation of stents in early life seems to interfere little with the hosts' immune system and might help to open up the right ventricular outflow tract by mechanical forces and regressive changes in adjacent muscular tissue.

Left Ventricular Physiology and Ventricular-Vascular Interactions in Young Patients After Heart Transplantation.

Background In patients after heart transplantation, systemic arterial hypertension and enhanced central aortic stiffness contribute to increased ventricular afterload, which might lead to graft dysfunction. The aim of our study was to characterize systemic arterial elastance and its impact on left ventricular function and ventriculo-arterial coupling in a cohort of children, adolescents, and young adults after heart transplantation using invasive conductance catheter technique. Methods and Results Thirty patients who had heart transplants (age, 20.0±6.5 years, 7 female) underwent invasive cardiac catheterization including pressure-volume loop analysis. Load-independent parameters of systolic (ventricular elastance [Ees]) and diastolic (ventricular compliance) function as well as systemic arterial elastance (Ea, end-systolic pressure/stroke volume) and ventriculo-arterial coupling (Ea/Ees) were assessed at baseline level and during dobutamine infusion (10 µg/kg/min). Ees showed an appropriate increase under inotropic stimulation from 0.43 (0.11-2.52) to 1.00 (0.20-5.10) mm Hg/mL/m2 (P<0.0001), whereas ventricular compliance remained rather unchanged (0.16±0.10 mm Hg/mL/m2 to 0.12±0.07 mm Hg/mL/m2; P=0.10). Ventriculo-arterial coupling Ea/Ees was abnormal at rest and did not improve significantly under dobutamine (1.7 [0.6-6.7] to 1.3 [0.5-4.9], P=0.70) due to a simultaneous rise in Ea from 0.71 (0.37-2.82) to 1.10 (0.52-4.03) mm Hg/mL/m2 (P<0.0001). Both Ees and ventricular compliance were significantly associated with Ea at baseline and under dobutamine infusion. Conclusions Patients who underwent heart transplantation show impaired ventriculo-arterial coupling at rest and under inotropic stimulation despite preserved left ventricular contractile reserve. An abnormal response in vascular function resulting in increased afterload seems to represent an important factor that may play a role for the development of late graft failure.

Transient Recurrent Laryngeal Nerve Palsy after Interventional Therapy.

BACKGROUND: Hoarseness due to laryngeal nerve injury is a known complication after cardiothoracic surgery involving the aortic arch. However, this complication is only rarely reported after catheter interventions. RESULTS: In this article we present the unusual case of a left-sided vocal cord paralysis in four patients after primary stenting of a re-coarctation, re-dilatation of a stented coarctation, a primary stenting of the left pulmonary artery (LPA), and prestenting for percutaneous pulmonary valve implantation with dilation of the LPA. After implanting bare metal stents, it is common practice, whilst contemplating the diameters of the adjacent structures, to optimize the stent diameter in a two-step procedure and dilate the stent until a maximum diameter is achieved and there is no residual gradient after applying this technique. Four of our patients experienced hoarseness after the intervention and a vocal cord paralysis was diagnosed. Angiography revealed no signs of extravasation or dissection. Clinical symptoms improved over the course of the following 6 months; patients with interventions at the aortic arch showed a complete remission, patients with procedures involving the LPA showed only mild regression of the symptoms. CONCLUSION: To our knowledge, this complication (Ortner's syndrome, cardiovocal syndrome) after such interventions has rarely been reported before. Although a rare complication, the recognition of these symptoms may support colleagues in managing affected patients. In addition, awareness for hoarseness after interventional therapies and systematic screening for this complication might help to identify patients at risk in the future.

Recovery of Biventricular Function After Catheter Intervention or Surgery for Neonatal Coarctation of the Aorta.

Background: Critical coarctation of the aorta (CoA) is a life-threatening condition in newborns that is associated with biventricular dysfunction. Objectives: The purpose of this study was to examine clinical outcome and echocardiographic changes in isthmus diameter and biventricular function in newborns with critical CoA treated with balloon dilation/stent placement or surgery. Methods: This is a retrospective single-center cohort study of 26 consecutive neonates with isolated critical CoA, who underwent transcatheter intervention (balloon angioplasty/stent; n = 10) or surgical CoA-repair (n = 16) (2012-2021). Isthmus dimensions and biventricular function at baseline and at hospital discharge were examined by echocardiography, including strain analysis of systolic and diastolic function using 2-dimensional speckle tracking. Results: Cardiogenic shock at hospital admission was more frequent in the interventional vs the surgical cohort (50% vs 25% of neonates). Echocardiographic isthmus diameter increased with therapy by 0.9 ± 0.1 mm and 1.0 ± 0.1 mm, respectively. Severe systolic left ventricular (LV) dysfunction was more common in interventional patients pre-therapy (LV ejection fraction <50% in 90% vs 38% of surgical patients), resulting in strongly reduced longitudinal strain (LV: -12.3% vs -16.3%; right ventricle:-13.8% vs -16.1% in the interventional and surgical patients, respectively). Prior to hospital discharge, all 26 patients had full recovery of biventricular systolic function, including normalization of longitudinal, radial, and circumferential LV strain and longitudinal right ventricular free wall strain. Improvement of LV diastolic function by strain analysis was evident in both cohorts pre-hospital discharge. Conclusions: Initial treatment of isolated CoA by percutaneous transcatheter intervention or surgical repair results in recovery of biventricular systolic function, making transcatheter treatment particularly suitable as rescue therapy for neonates with critical CoA.

Long-term outcome of primary percutaneous stent angioplasty for pediatric posttransplantation portal vein stenosis.

This study aims to evaluate the long-term efficacy and reintervention rate after primary percutaneous portal vein stent angioplasty for portal vein stenosis (PVS) in pediatric liver transplantation (LT) recipients. From 2004 to 2020, a total of 470 pediatric LTs were performed in our center. All cases were screened for interventional PVS treatment and analyzed retrospectively. We identified 44 patients with 46 percutaneous angioplasties for posttransplantation PVS. The median interval from LT to percutaneous catheter intervention was 5 months (16 days-104 months) with a median follow-up (f/u) period after catheter intervention of 5.7 years (2-156 months). In 40 patients, an endovascular stent was placed as primary (n = 38) or secondary (n = 2) intervention. The median age at stent placement was 23 (6-179) months with a median weight of 10 kg (6-46 kg). Technical success and relief of PVS were achieved in all patients irrespective of age or weight. Adverse events occurred peri-interventionally in two patients and were resolved with standard care. All primary portal vein (PV) stents remained patent until the end of f/u. Reinterventions have been successfully performed in 10 patients for suspected or proven restenosis, resulting in a primary patency rate of 75% and an assisted patency rate of 25%. The median time to reintervention was 6.2 years (range 1-10 years). The need for reintervention was independent of age or weight at both transplantation and initial angioplasty as well as of additional risk factors due to portal hypertension. Percutaneous transhepatic PV stent angioplasty in children is safe and effective in all age groups, with excellent long-term patency. Primary stent angioplasty should be considered as first-line treatment for PVS after pediatric LT.

Interventional Bronchus Occlusion Using Amplatzer Devices - A Promising Treatment Option for Children with Persistent Air Leak.

BACKGROUND: Persistent air leak (PAL) is a severe complication of secondary spontaneous pneumothorax (SSP). Surgical interventions are usually successful when medical treatment fails, but can be associated with significant complications and loss of potentially recoverable lung parenchyma. METHODS: Retrospective analysis of efficacy and safety of interventional bronchus occlusions (IBO) using Amplatzer devices (ADs) in children with PAL secondary to SSP. RESULTS: Six patients (four males, 4-15 years of age) underwent IBO using ADs as treatment for PAL. Necrotizing pneumonia (NP) was the most common cause (n=4) of PAL. Three patients were previously healthy and three suffered from chronic lung disease. All patients required at least two chest tubes prior to the intervention for a duration of 15-43 days and all required oxygen or higher level of ventilatory support. In three cases, previous surgical interventions had been performed without success. All children improved after endobronchial intervention and we observed no associated complications. All chest tubes were removed within 5-25 days post IBO. In patients with PAL related to NP (n=4), occluders were removed bronchoscopically without re-occurrence of pneumothorax after a mean of 70 days (IQR: 46.5-94). CONCLUSION: IBO using ADs is a safe and valuable treatment option in children with PAL independent of disease severity and underlying cause. A major advantage of this procedure is its less invasiveness compared to surgery and the parenchyma- preserving approach.

Circulating Interleukin-7 in Human Pulmonary Arterial Hypertension.

Objectives: Interleukin-7 (IL-7) secures B cell maturation, regulatory T and natural killer (NK) cell survival, and homeostasis, all of which are important for beneficial immunomodulation in pulmonary arterial hypertension (PAH). However, the role and potential impact of IL-7, VEGF-C and the vascular injury markers ICAM-1, and VCAM-1 on the pathobiology and severity of PAH is unknown. Methods: EDTA blood was collected during cardiac catheterization from the superior vena cava (SVC), pulmonary artery (PA), and ascending aorta (AAO) in children with pulmonary hypertension (PH) [n = 10; 9.1 (3.9-18.5) years] and non-PH controls [n = 10; 10.5 (2.0-17.3) years]. Compartment-specific plasma concentrations of IL-7, VEGF-C, aldosterone, ICAM-1, and VCAM-1 were determined using Meso Scale Discovery's multi array technology and the LIAISON Aldosterone Assay. Results: Children with PH had approximately 50% lower IL-7 (p < 0.01) and 59% lower VEGF-C plasma levels (p < 0.001) in the SVC, PA, and AAO versus non-PH controls. IL-7 and VEGF-C concentrations negatively correlated with the pulmonary vascular resistance (PVR)/systemic vascular resistance (SVR) ratio (rho = -0.51 and r = -0.62, respectively). Central-venous IL-7 strongly positively correlated with VEGF-C (r = 0.81). Most patients had a step down in ICAM-1 and VCAM-1 plasma concentrations across the pulmonary circulation and both ICAM-1 and VCAM-1 transpulmonary gradients negatively correlated with invasive hemodynamics. Conclusion: This manuscript is the first report on decreased circulating IL-7 and VEGF-C plasma concentrations in human PAH and their inverse correlations with invasive surrogates of PAH severity. Additional and larger studies are needed to explore the role of the immune-modulatory IL-7 and VEGF-C in pediatric and adult PAH.

A word of caution: diabolic behaviour of AndraStents®: inflation of supporting balloon leads to "diabolo"-misconfiguration of the stent.

AIMS: Transcatheter implantation of pulmonary balloon-expandable stent-valves requires pre-stenting of the right ventricular outflow tract with large calibre stents. To increase awareness of the associated risks of this part of transcatheter pulmonary valve replacement therapy, we report potential fatal complications during the implantation of AndraStents® in the right ventricular outflow tract in six cases from five different European institutions and their management. METHOD AND RESULT: We present a retrospective case series analysis looking at the time period from 2013 to 2018. Of 127 AndraStents® implanted in the right ventricular outflow tract, in six patients, age from 13 to 71 years, a misconfiguration of the AndraStent® occurred forming a "diabolo"-configuration. During inflation of the balloon, the stent showed extreme "dog-boning", an expansion of the stent at both ends with the middle part remaining unexpanded. This led to rupture of the balloon and loss of manoeuvrability in four patients. Out of the total six cases, in four patients the stent was eventually expanded with high-pressure balloons, and in one case the stent was surgically retrieved. In one patient, in whom a percutaneous retrieval of the embolised stent was attempted, a fatal bleeding occurred. CONCLUSIONS: Pre-stenting of the right ventricular outflow tract by AndraStents® can lead to misconfiguration of the stent with potentially fatal complications. Rescue strategies of misconfigured stents include stent inflation and placement with high pressure non-compliant balloons or surgical backup. Interventional retrieval measures of AndraStents® cannot be advised.

Feasibility, safety and diagnostic impact of endomyocardial biopsies for the diagnosis of myocardial disease in children and adolescents.

AIMS: Endomyocardial biopsies (EMBs) are performed infrequently in children owing to significant past complication rates and controversial discussions about the therapeutic value of results. The objective of this study was to investigate the safety and feasibility of EMBs for suspected myocardial disease in relation to their clinical value. METHODS AND RESULTS: We performed a retrospective multicentre review of the Working Group for Interventional Cardiology of the German Society for Paediatric Cardiology. During three consecutive years, 206 EMBs (84 female/mean age 8.95±6.62 years) were performed and analysed at 15 heart centres. In the majority of cases, biopsies were taken from the right ventricle (RV/89.8%; p<0.001). The overall complication rate was 9.7%, whereas major complications occurred in only 0.97% of cases. Risk factors associated with a higher complication rate were biopsy during the first year of life (20.5%) and from the left ventricle (31.1%) (p<0.05). There was no procedure-related mortality. Treatment was changed in 18.0% of cases based on biopsy results. CONCLUSIONS: Today, endomyocardial biopsies in older children with suspected myocardial disease can be performed safely with a low risk of major complications and mortality, whereas the risk of complications if the biopsy is carried out in the first year of life or taken from the left ventricle remains high.

First-in-child use of the oral soluble guanylate cyclase stimulator riociguat in pulmonary arterial hypertension.

Riociguat has been approved for use in adults with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension. No clinical data on its therapeutic use in children with PAH are currently available. We report the case of a now four-year-old boy who initially presented at the age of 10 months with suprasystemic pulmonary hypertension (PH) and right ventricular (RV) failure, vomiting, peripheral cyanosis, and failure to thrive. Cardiac catheterization revealed severe PAH. At radiologic suspicion of interstitial lung disease, repeated CT scan and an open lung biopsy were performed but could not clarify the entity of PAH. Given the demonstrated vasoreactivity, the boy was started on the calcium channel blocker amlodipine, in combination with the endothelin-1 receptor antagonist bosentan. Two years later, based on persistently systemic PAH with lost vasoreactivity, PAH therapy was changed to bosentan and phosphodiesterase-5 inhibitor sildenafil. No significant improvement on the aforementioned therapy was seen, so that the patient was referred to our institution. Invasive hemodynamic evaluation showed suprasystemic PAH and marked acute vasoreactivity (PAP 127/103/83 mmHg, PVRi 23.48 WU·m2 and PVR/SVR ratio 1.59 at baseline vs. PVRi 5.89 WU·m2 and PVR/SVR ratio 0.93 under O2/NO). Subsequently, we switched the patient from sildenafil to riociguat. After six months on bosentan/riociguat, the patient showed a marked decrease in PVR/SVR and transpulmonary pressure gradients, in RV hypertrophy, PA acceleration time, and left ventricular-eccentricity index. Clinically, the patient improved in pediatric functional class from 2/3 to 1. In conclusion, off-label use of oral riociguat may be considered in selected children with severe PAH.

Is mesocardia with left-sided caval vein draining to coronary sinus a contraindication for a percutaneous pulmonary valve implantation? A case description.

Introduction Although the right jugular vein approach for percutaneous pulmonary valve implantation is well described, there are no reports that describe a percutaneous pulmonary valve implantation through a left superior caval vein to coronary sinus pathway. Case A 14-year-old female with tetralogy of Fallot, mesocardia, left superior caval vein draining into the coronary sinus, and hemiazygos continuation of the inferior caval vein underwent ventricular septal defect closure, with homograft insertion from the right ventricle to the pulmonary artery, patch augmentation of the left pulmonary artery, and creation of an atrial communication. Thereafter followed numerous catheterisations and interventions with stent implantation for stenosis of the left pulmonary artery and the homograft, as did device closure of the atrial communication. When she was a 12-year-old, the indications for a percutaneous pulmonary valve implantation were fulfilled and she underwent implantation of a 22 mm Melody® valve through the left superior caval vein. The extra-stiff exchange wire was pre-formed into a "U-spiral"-type configuration, according to the underlying anatomy, in order to provide a smooth route for the delivery of stents, to create the landing zone, and for the implantation of the Melody "ensemble". The procedure was performed under deep sedation according to our standard protocol. The duration of the procedure was 172 min and the radiation time was 24.9 min. CONCLUSION: On the basis of this unique experience, percutaneous pulmonary valve implantation is safe and feasible even in patients with unusual anatomy. Crucial is the "U-spiral" shaped configuration of the guide wire.

Interventional VSD-Closure with the Nit-Occlud® Lê VSD-Coil in 110 Patients: Early and Midterm Results of the EUREVECO-Registry.

In August 2010, the Nit-Occlud® Lê (EUREVECO) became available for transcatheter coil occlusion of ventricular septal defects (VSDs). Retrospective European Registry for VSD Closure using the Nit-Occlud® Lê-VSD-Coil; analysis of the feasibility, results, safety and follow-up of VSD-closure over a 3-year period in 18 European centers. In 102 of 111 patients (female 66), successful VSD closure was performed (mean age 8.2 years, mean weight 28.82 kg), 81 perimembranous VSDs (48 with aneurysm), 30 muscular VSDs, mean procedure time was 121.1 min, and mean fluoroscopy time was 26.3 min. Short- and midterm term follow-up was possible in 100/102 patients, there was 1 embolization and 1 explantation after 24 months. Immediate complete closure occurred in 49 of 101 patients (48.5%), trivial residual shunt was present in 51 (50.0%), closure rate was 95% after 6 months and 97% after 1 year. Out of the 102 patients, there were 2 severe complications (1.8%) (1 severe hemolysis, 1 embolization) and 8 moderate/transient (=7.2%) including 1 transient AV block. During a mean follow-up period of 31.3 months (range 24-48) and a total follow-up time of 224.75 patient years, no further problems occurred. VSD closure with the Nit-Occlud® Lê VSD coil is feasible and safe with a minimal risk of severe side effects. The long-term effects and safety require further clinical follow-up studies.

Closure of very large PDA with pulmonary hypertension: Initial clinical case-series with the new Occlutech® PDA occluder.

OBJECTIVE: We report our recent experience with the new Occlutech® PDA Occluder, which seems suitable especially for closure of large patent ductus arteriosus (PDA) sizes with elevated pulmonary artery pressure (PAH). BACKGROUND: Although considered a standard procedure in pediatric cath labs, closure of very large PDA (PDA/Aorta ratio > 0.5) and PAH remains a challenge. METHODS/RESULTS: The Occlutech® PDA occluder was used in eight children and adolescents (age 4-16, median 10.75 years), body weight from 14 to 54 kg (median 21 kg) with very large PDA and PAH: PDA diameter was 5-13 mm (median 10 mm); PAP/Aortic pressure ratio was 0.58-0.96. Sufficient occlusion of the PDA was documented by angiography and/or echocardiography in all cases. Four different device sizes were selected: Minimal diameter 6-14 mm (median 12 mm), length 6.3-16 mm (median 14 mm), aortic disc 13-24 mm (median 20 mm), size at the pulmonary end 8-18 mm (median 15 mm). A balloon test occlusion of the PDA was performed in five patients in order to evaulate the decline of pulmonary artery pressure or to delineate the exact anatomy of the PDA. Before release of the device, a careful "wiggle manoevre" was performed to assess the stability of the implanted device and to proof the inability to embolize to the aorta. CONCLUSIONS: With the new Occlutech® PDA Occluder closure of very large PDAs and PAH is feasible and efficient. The wider pulmonary artery end of the Occlutech® PDA Occluder offers enhanced stability and reduces the risk of embolization. © 2016 Wiley Periodicals, Inc.

Closure of Secundum Atrial Septal Defects by Using the Occlutech Occluder Devices in More Than 1300 Patients: The IRFACODE Project: A Retrospective Case Series.

BACKGROUND: The Occlutech Figulla ASD device series (OFSO) shows an improved device design for interventional ASD closure, larger follow-up series are missing. METHODS: We retrospectively reviewed the feasibility, safety, implantation properties, results, and follow-up of ASD closure using Occlutech devices over a 5 year period by establishing a multi-institutional collaborative result registry with 16 contributing centers from 11 countries (IRFACODE). RESULTS: In 1315 patients of all age groups (female 66.9%), successful (98%) ASD closure was performed (mean age 28.9 years, weight 52 kg, height 148.6 cm). Of the defects, 47.9% showed no or only a deficient aortic rim; in 11.9%, there was more than one defect; a septum aneurysm was present in 21.5%; and the mean implanted device size was 20.5 mm. Immediate closure was achieved in 78.6%, at discharge in 83.1%, and 96.4% and 97.3% at 6 and 12 months follow-up, respectively. During a mean follow-up of 2.7 years (in total 3597 patient years), significant complications were minimal (total = 8, <1%) with secondary device embolizations in five and AV-blocks in three patients. No erosion or death was reported. CONCLUSION: ASD closure using OFSO is feasible in a large variety of patients, safe with only a minimal risk of severe side effects and especially without any aortic erosions despite a large percentage of large and complicated defects. © 2016 Wiley Periodicals, Inc.

"Intraoperative hybrid stenting of recurrent coarctation and arch hypoplasia with large stents in patients with univentricular hearts".

BACKGROUND: Obstruction of the reconstructed aortic arch, tubular hypoplasia and recurrent coarctation (RC) is an important risk factor in univentricular physiology. For the past two years we have adopted the concept of intraoperative hybrid stenting of RC and arch hypoplasia with large stents in patients with univentricular hearts as standard care procedure. METHOD/RESULT: Retrospective analysis of the anatomy and procedural outcome of 14 patients was scheduled for intraoperative stenting of the aortic arch (12 during surgery for BCPS, 2 during Fontan completion). The median age was 5.3 months, weight 5.5 kg, height 62 cm. Five patients had tubular hypoplasia and 9 patients had distal stenosis of the aortic arch. Nine patients had a previous balloon dilatation. The mean diameter of the distal arch was 11.0mm, at the coarctation 5.1mm, at the level of the diaphragm 8.2mm (CoA-index 0.62). Intraoperative stenting was performed in 13/14 patients. Stents were implanted with a mean balloon diameter of 10.8mm (SD 3.4mm). The achieved final mean diameter was 9.8mm (mean, SD 2.8mm) with an oversized Coa-index of 1.2. There was no re-coarctation at a mean follow-up of 7.3 months (range 3 to 24), the maximum flow velocity of 2m/s across the stented lesion assessed by ECHO. CONCLUSION: This hybrid approach is an easy and safe concept to manage recurrent aortic arch hypoplasia and stenosis. The use of large stents allows redilatation to adult size diameters later on.

Optimal septum alignment of the Figulla Flex occluder to the atrial septum in patients with secundum atrial septal defects.

AIMS: To investigate the implantation safety, anatomic performance and septal alignment of the Occlutech Figulla Flex occluder (FFO) device, an atrial septal defect (ASD) closure device with specific left-sided deployment characteristics and right-sided septal alignment properties. METHODS AND RESULTS: Between January 2011 and December 2013 we prospectively collected the change of orientation of the device to the septum during the release process and the feasibility of implantation of the FFO in 122 patients. The mean age was 10.7 years (±10.2), weight 32.9 kg (±20.3), and height 129.4 cm (±30). Devices used were 9 (n=13), 10.5 (n=16), 12 (n=16), 15 (n=39), 18 (n=17), 21 (n=8), 24 (n=5), 27 (n=7) and 30 mm (n=3) in size. No additional implantation techniques were required. Before release, the mean angles of the left and right-sided discs were 29.2° (±9.9°) and 43.4° (±9.2°) to the body axis, and 18.7° (±8.7°) and 27.0° (±10°) immediately thereafter. Thus, there was only a slight change in orientation of the left-sided (10.6°±7.5°) and right-sided (16.3°±7.9°) discs. CONCLUSIONS: The design of this occluder system results in an ideal septum alignment which increases its feasibility as well as patient safety during implantation.

Substantial radiation reduction in pediatric and adult congenital heart disease interventions with a novel X-ray imaging technology.

BACKGROUND: Pediatric catheterization exposes patients to varying radiation doses. Concerns over the effects of X-ray radiation dose on the patient population have increased in recent years. This study aims at quantifying the patient radiation dose reduction after the introduction of an X-ray imaging technology using advanced real time image noise reduction algorithms and optimized acquisition chain for fluoroscopy and exposure in a pediatric and adult population with congenital heart disease. METHODS: Patient and radiation dose data was retrospectively collected (July 2012-February 2013) for 338 consecutive patients treated with a system using state of the art image processing and reference acquisition chain (referred as "reference system"). The same data was collected (March-October 2013) for 329 consecutive patients treated with the new imaging technology (Philips AlluraClarity, referred as "new system"). Patients were divided into three weight groups: A) below 10 kg, B) 10-40 kg, and C) over 40 kg. Radiation dose was quantified using dose area product (DAP), while procedure complexity using fluoroscopy time, procedure duration and volume of contrast medium. RESULTS: The new system provides significant patient dose reduction compared to the reference system. Median DAP values were reduced in group A) from 140.6 cGy·cm2 to 60.7 cGy·cm2, in group B) from 700.0 cGy·cm2 to 202.2 cGy·cm2 and in group C) from 4490.4 cGy·cm2 to 1979.8 cGy·cm2 with reduction of 57%, 71% and 56% respectively (p < 0.0001 for all groups). CONCLUSIONS: Despite no other changes in procedural approach, the novel X-ray imaging technology provided substantial radiation dose reduction of 56% or higher.