Cardiac Development and Factors Influencing the Development of Congenital Heart Defects (CHDs): Part I.

The traditional description of cardiac development involves progression from a cardiac crescent to a linear heart tube, which in the phase of transformation into a mature heart forms a cardiac loop and is divided with the septa into individual cavities. Cardiac morphogenesis involves numerous types of cells originating outside the initial cardiac crescent, including neural crest cells, cells of the second heart field origin, and epicardial progenitor cells. The development of the fetal heart and circulatory system is subject to regulatation by both genetic and environmental processes. The etiology for cases with congenital heart defects (CHDs) is largely unknown, but several genetic anomalies, some maternal illnesses, and prenatal exposures to specific therapeutic and non-therapeutic drugs are generally accepted as risk factors. New techniques for studying heart development have revealed many aspects of cardiac morphogenesis that are important in the development of CHDs, in particular transposition of the great arteries.

Prospective multicenter study of the breakable babystent for treatment of aortic coarctation in newborns and infants.

To assess the efficacy and safety of a breakable BabyStent to treat complex aortic coarctation (CoA) in early childhood. Although recommended in several guidelines, there is no approved aortic stent for young infants, because of the dilemma between two mandatory requirements: expandable up to adult size on the one hand, and small enough to fit through a baby's femoral artery on the other. Prospective interventional, multi-center clinical trial with the breakable Osypka BabyStent® (OBS). The OBS is a low-profile, 15-mm long cobalt-chromium stent, pre-mounted on a 6 mm balloon and inserted via a 4 Fr sheath. After implantation, its diameter is adjustable from 6 to 12 mm by balloon dilation. Further dilation opens predefined joints enabling unrestricted growth. Nineteen patients (9 male), median age 112 days (range: 7-539), median body weight 5.6 kg (range: 2.4-8.4) were deemed high risk and underwent stent implantation. Of those, 74% suffered from re-CoA following surgery, 53% had additional cardiac and 21% noncardiac malformations. Our primary combined endpoint was fulfilled: All stents were implanted in the desired region, and a >50% intrastenotic diameter-extension was achieved in 15 patients (78.9%, 80% confidence interval [62.2; 90.5], 95% confidence interval [54.4; 93.9]). Secondary endpoint confirmed that the OBS fits the baby's femoral vessel diameter. All children survived the procedure and 12-month follow-up. This stent enables percutaneous stenting of complex aortic coarctation to treat high-risk newborns and infants.

Surgically placed radiopaque markers: Proof-of-concept of a novel technique to facilitate percutaneous interventions in neonates and infants.

OBJECTIVES: Aim of this study was to evaluate feasibility and benefit of self-designed, radiopaque markers as a novel technique in neonates and infants with shunt- or duct-dependent lesions. BACKGROUND: Surgically placed radiopaque markers have the potential to facilitate postoperative percutaneous interventions. METHODS: All consecutive children with surgically placed radiopaque markers involving systemic-to-pulmonary artery connections or arterial ducts in the context of hybrid palliation and subsequent cardiac catheterization between January 2013 and March 2019 were included in this analysis. Our primary endpoint was our concept's feasibility, which we defined as a combination of surgical feasibility and the percutaneous intervention's success. Secondary endpoint was the rate of complications resulting from the surgical procedure or during catheterization. RESULTS: Radiopaque markers that reveal the proximal entry of a surgical shunt or the arterial duct proved to be a feasible and beneficial approach in 25 postoperative catheterizations. The markers' high accuracy enabled easy probing and proper stent positioning in 13 neonates with a median age and weight of 121 days (range 9-356) and 4.7 kg (1.6-9.4) at the intervention. No procedural complications or unanticipated events associated with the radiopaque marker occurred. The markers were never lost, never migrated, and caused no local obstructive lesion. Surgical removal was straightforward in all patients. CONCLUSIONS: Radiopaque markers are a promising and refined technique to substantially facilitate target vessel access and enabling the accurate positioning of stents during postoperative percutaneous procedures.

Collateral closure in congenital heart defects with Amplatzer vascular plugs: single-center experience and a simplified delivery technique for exceptional cases.

The study describes our experience with Amplatzer Vascular Plugs (AVP2 and 4) and highlights a more refindes telescopic technique for AVP2 delivery. AVPs are well-established occlusion devices for vascular anomalies in congenital heart disease (CHD). The AVP2 is sometimes preferred to the AVP4 due to its shorter length, flat-profiled retention disks, and the availability of larger diameters, but its profile requires a larger inner lumen for safe delivery. The latter may actually hamper access to target lesions. This is a retrospective analysis of all CHD patients treated with the AVP2 and AVP4 between 12/2012 and 12/2015. Target vessels were characterized, measured, and the device-to-vessel diameter ratio calculated. A modified pigtail technique for AVP2 delivery was frequently used: a floppy wire was simply reinforced by the curved tip of a pigtail catheter (instead of the long sheath's dilator) to guide the required delivery sheath towards the desired landing zone. 59 patients with a median age and bodyweight of 3.0 years (range 0.1-75) and 13.8 kg (range 2.5-80) underwent the implantation of 106 plug-devices (30 AVP2, 76 AVP4) in 91 target vessels. Indications for their use were ductus arteriosus (19%), aortopulmonary (43%) as well as venovenous collaterals (34%) and other miscellaneous lesions (4%). The pigtail-supported AVP2 delivery in six patients proved very convenient. No complications occurred. AVPs are excellent devices for embolizing shunt vessels in CHD patients. Here, we describe a simplified telescoping technique for AVP2 delivery to enter curvy target lesions gently and efficiently.

Management of a dissection of matrix P right ventricular-to-pulmonary artery conduit by implanting two pre-stents and a melody valve.

Reconstructing the right ventricular outflow tract and pulmonary valve via a bovine-derived valve conduit such as Matrix-P-Xenograft is a common surgical repair technique for pulmonary atresia and ventricular septal defect. After conduit degeneration due to calcification or aneurysmal dilatation, percutaneous transvenous stenting of the right ventricular outflow tract followed by pulmonary valve implantation has become the standard interventional treatment. Applied to stenotic conduits, the method is considered safe and effective. An important but seldom-reported problem is graft failure related to the formation of a Matrix membrane due to inflammation and fibrosis inside the xenograft, which can cause serious problems when dissection and rupture occur during transcatheter intervention. The torn pseudomembrane may cause the complete obstruction of both pulmonary arteries, resulting in a life-threatening situation requiring rapid intervention, as in this case presentation. © 2016 Wiley Periodicals, Inc.

Implementing and Assessing a Standardized Protocol for Weaning Children Successfully From Extracorporeal Life Support.

Extracorporeal life support (ECLS) weaning is a complex interdisciplinary process with no clear guidelines. To assess ventricular and pulmonary function as well as hemodynamics including end-organ recovery during ECLS weaning, we developed a standardized weaning protocol. We reviewed our experience 2 years later to assess its feasibility and efficacy. In 2015 we established an inter-professional, standardized, stepwise protocol for weaning from ECLS. If the patient did not require further surgery, weaning was conducted bedside in the intensive care unit (ICU). Most of the weaning procedures are guided via echocardiography. Data acquisition began at baseline level, followed by four-step course (each step lasting 10 min), entailing flow-reduction and ending 30 min after decannulation. Moreover, data from the preprotocol era are presented. Between May 2015 and 2017, 26 consecutive patients (18 male), median age 177 days (2 days-20 years) required ECLS with median support of 4 (2-11) days. Excluding eight not weanable patients, 21 standardized weaning procedures were protocolled in the remaining 18 children. Our generally successful protocol-guided weaning rate (with at least 24-h survival) was 89%, with a discharge home rate of 58%. Practical application of the novel standard protocol seems to facilitate ECLS weaning and to improve its success rate. The protocol can be administered as part of standard bedside ICU assessment.

Echocardiographic characteristics in Fontan patients before the onset of protein-losing enteropathy or plastic bronchitis.

BACKGROUND: It was this study's objective to evaluate the echocardiographic characteristics and flow patterns in abdominal arteries of Fontan patients before the onset of protein-losing enteropathy (PLE) or plastic bronchitis (PB). DESIGN: In this retrospective cohort investigation, we examined 170 Fontan patients from 32 different centers who had undergone echocardiographic and Doppler ultrasound examinations between June 2006 and May 2013. Follow-up questionnaires were completed by 105 patients a median of 5.3 (1.5-8.5) years later to evaluate whether one of the complications had occurred since the examinations. RESULTS: A total of 91 patients never developed PLE or PB ("non-PLE/PB"); they were compared to 14 affected patients. Eight of the 14 patients had already been diagnosed with "present PLE/PB" when examined. Six "future PLE/PB" patients developed those complications later on and were identified on follow-up. The "future PLE/PB" patients presented significantly slower diastolic flow velocities in the celiac artery (0.1 (0.1-0.5) m/s vs 0.3 (0.1-1.0) m/s (P = .04) and in the superior mesenteric artery (0.0 (0.0-0.2) m/s vs 0.2 (0.0-0.6) m/s, P = .02) than the "non-PLE/PB" group. Median resistance indices in the celiac artery were significantly higher (0.9 (0.8-0.9) m/s vs 0.8 (0.6-0.9) m/s, (P = .01)) even before the onset of PLE or PB. CONCLUSION: An elevated flow resistance in the celiac artery may prevail in Fontan patients before the clinical manifestation of PLE or PB.

Multicenter midterm follow-up results using the gore septal occluder for atrial septal defect closure in pediatric patients.

OBJECTIVES: To assess the safety and efficacy of the Gore Septal Occluder (GSO) used for device-closure of significant secundum-type atrial septal defects (ASD II) focusing on pediatric patients. BACKGROUND: The GSO is a patch-like double disc device. Due to its design, it is assumed to be safe, even when implanted in ASDs with deficient retro-aortic rims. METHODS: Multicenter retrospective analysis of consecutive children and adolescents with a GSO in situ for at least 12 months according to a 1- to 4-year midterm follow-up. RESULTS: Hundred and seventy three pediatric patients were enrolled. At implantation, median age was 6 years (range 0.7-17.9), median body weight and length were 21 kg (6.4-95) and 119 cm (65-193). Median follow-up period was 20 months (range 12-51). ASD anatomy was comprised of single defects in 131 patients (76%), multi-fenestrated defects in 42 (24%), and deficient retro-aortic rims in 33 (19%). Follow-up confirmed an overall closure-rate of 95.4%. Small residual shunts were reported in eight patients (4.6%) without need for any re-intervention. Complications were classified as minor events both during the initial procedure (9 patients, 5.2%) and on follow-up (another 9 patients), including transient AV block II in three patients (1.8%) and four snare-retrievals (2.4%) during the initial procedure. CONCLUSIONS: Periprocedural and midterm follow-up data have shown the GSO to be effective and safe for ASD device closure in children and adolescents. GSO may be considered the first-choice device in deficient retro-aortic rims and multi-fenestrated defects, when covering most of the atrial septum is necessary. © 2016 Wiley Periodicals, Inc.

Closure of patent foramen ovale defects using GORE® CARDIOFORM septal occluder: Results from a prospective European multicenter study.

AIMS: The GORE® CARDIOFORM Septal Occluder (GSO) is a novel device designed for rapid and effective closure of patent foramen ovale (PFO) which has distinctive features making it suitable for a broad spectrum of anatomical variations. We report the procedural and 6 months follow-up results of the first prospective, multicenter study using GSO. METHODS AND RESULTS: This single-arm study included 150 subjects undergoing closure of PFO in 10 European centers. In 149 out of 150 patients implantation of a GSO device was successful. One patient had a different PFO-closure device implanted. Periprocedural complications were few including one patient with suspected transient ischemic attack, two access site bleedings, and one patient with AV-fistula. No device embolization occurred. During the 6-month follow-up period one patient had a transient asymptomatic thrombus on the device and four patients (2.6%) were diagnosed new onset paroxysmal atrial fibrillation, which were successfully treated. No thrombembolic events occurred. Closure was successful in 94.2% of subjects at discharge evaluation and 96.9% at 6 months follow-up. CONCLUSION: This prospective, multicenter study adds to previous published data and suggests that GSO is a versatile device for PFO closure with high procedural and closure success rates and low complication rates through mid-term follow-up. © 2017 Wiley Periodicals, Inc.

Long-Term Follow-Up on Health-Related Quality of Life After Mechanical Circulatory Support in Children.

OBJECTIVE: The objective of this study was to evaluate health-related quality of life in long-term survivors of mechanical circulatory support after acute cardiopulmonary failure. DESIGN: Prospective follow-up study. SETTING: Single-institutional in a center for congenital heart disease and pediatric cardiology. PATIENTS: Fifty patients who underwent 58 mechanical circulatory support therapies in our institution from 2001 to 2012. Median age was 2 (0-213) months, and median supporting time was 5 (1-234) days. Indication groups: 1) extracorporeal life support in low cardiac output: 30 cases (52%); 2) extracorporeal cardiopulmonary resuscitation: 13 cases (22%); 3) extracorporeal membrane oxygenation in acute respiratory distress syndrome: four cases (7%); and 4) ventricular assist devices: 11 cases (19%). INTERVENTIONS: Health-related quality of life was measured using standardized questionnaires according to the age group and completed by either parent proxies in children under 7 years old or the survivors themselves. MEASUREMENTS AND MAIN RESULTS: Fifty percentage of the patients were discharged home, and 22 long-term survivors (44%) were studied prospectively for health-related quality of life. Median follow-up period was 4.5 (0.3-11.3) years. Median age at follow-up was 5 (0.6-29) years old. Nineteen long-term survivors filled in the health-related quality of life questionnaires and were classified into three age groups: 0-4 years (n = 7): median health-related quality of life score, 69 (59-86) points; 4-12 years (n = 7): median health-related quality of life score, 50 (48-85) points; older than 12 years (n = 5): median health-related quality of life score, 90 (80-100) points. CONCLUSION: Long-term survivors' health-related quality of life as reported by their parents is lower than that of healthy children. However, the self-assessed health-related quality of life of the patients older than 12 years in our group is comparable to a healthy control population.

An Early Glenn Operation May be Associated with the Later Occurrence of Protein-Losing Enteropathy in Fontan Patients : Association of Early Glenn and Failing Fontan.

Protein-losing enteropathy (PLE) and plastic bronchitis (PB) are major causes of long-term mortality after Fontan operation. The objective of this study was to determine early clinical risk factors before the onset of PLE and PB. In a cohort study, 106 Fontan patients between 2005 and 2013 were examined. A median of 5.3 (1.5-8.5) years later, follow-up questionnaires were used to group the patients in a PLE or PB group (n = 14) and a non-PLE/PB group (n = 92). Prevalence of PLE was 9.4% (n = 10) and of PB 3.8% (n = 4). At follow-up, five patients (4.7%) died of PLE or PB. Median age at death was 6.2 years (IQR 10.5, 95% CI 5.3-23.4). We observed no significant group differences in gender distribution (p = 0.73), ventricular morphology (p = 0.87), surgical technique (p = 0.64), conduit fenestration (p = 0.34), age at Fontan operation (p = 0.54), and need for diuretics (p = 0.56). Hypoplastic left heart syndrome was more frequent in the PLE/PB group 50 vs. 22.8% (p = 0.03) OR 3.4 (95% CI 1.1-10.8). The modified Glenn procedure was performed at a median age of 4 months (IQR 4.0) in the PLE/PB group versus 8 months (IQR 8.0) in the non-PLE/PB group (p = 0.01). The early Glenn procedure and hypoplastic left heart syndrome may be associated with the development of PLE and PB.

A new breakable stent for recoarctation in early infancy: Preliminary Clinical Experience.

OBJECTIVES: Transcatheter treatment of aortic coarctation (CoA) via stent implantation has become an established treatment option depending on the patient's age and CoA type. BACKGROUND: The Osypka BabyStent(®) is a low-profiled, balloon-expandable cobalt-chrome stent to treat aortic CoA in infants, which is breakable to permit unrestricted growth. We hereby evaluated our initial clinical experience to demonstrate the feasibility and efficacy of this new nonlicensed device, which we have occasionally implanted in critically ill patients or when redo-surgery would entail an excessively high risk. METHODS: Retrospective single-center analysis of all available data during and after treatment with a BabyStent implanted in infants with considerable re-CoA or reobstruction of the aortic arch after former surgery. All interventions took place under fluoroscopy and conscious sedation with local anesthesia or general anesthesia. RESULTS: Five BabyStents were implanted in four infants with technical success in all of them-median age 10 weeks (range 5-21), median bodyweight 3.8 kg (range 2.7-4.5). Aortic diameters enlarged from median 2.25 mm (range 1.5-3.3) to median 5.3 mm (range 4.6-6.0). The follow-up period lasting up to 26 months (median 8.5, range 2-26) was uneventful concerning stent-related complications. CONCLUSIONS: BabyStent(®) implantation for recoarctation was effective. However, our initial experience with the device is limited to short- and midterm follow-up only. None of the stents was subsequently overdilated with the intention to break due to our patients' limited somatic growth so far. A multicenter survey has been initiated to justify device approval.

Percutaneous Pulmonary Valve Implantation in the Patched Right Ventricular Outflow Tract 51 Years after Surgical Repair for Tetralogy of Fallot.

Percutaneous pulmonary valve implantation (PPVI) has become a widely practiced treatment option for patients with right ventricular outflow tract (RVOT) dysfunction. For this procedure, the Melody transcatheter pulmonary valve has become the most widely used system. On-label indications are limited to the treatment of failing circumferential conduits. However, there is growing but still limited experience with the off-label treatment of native or patched RVOTs. Here, the case is reported of a 57-year-old patient in whom redo-surgery for a dysfunctional pulmonary valve could be avoided by PPVI into the patched RVOT at 51 years after tetralogy of Fallot repair.

Stenting of Native Right Ventricular Outflow Tract Obstructions in Symptomatic Infants.

OBJECTIVE: To assess feasibility, safety and effectiveness of right ventricular outflow tract (RVOT) stenting in symptomatic young infants. METHODS: Multicentre evaluation of 35 patients intended to undergo RVOT stenting in 11 pediatric cardiac centres from 2009 to August 2011. RESULTS: Median age and weight at the time of first stent implantation were 8 weeks and 3.3 kg, with 40% of patients <3 kg. A total of 19 patients had suffered from hypoxemic spells, 8 patients were ventilated, 6 on inotropic support and 5 on prostaglandin infusion. Severe concomitant malformations were present in 11 patients, and acute infections in 2. Stenting of the RVOT was successfully performed in 33 patients, improving oxygen saturation from a median of 77 to 90% 2 days after intervention. Besides the 2 patients in whom RVOT stenting was not successful for technical reasons, there were no procedural complications. In 17 of 33 patients, 1-3 reinterventions were performed during follow-up, less than half of those were reinterventions in the RVOT. A total of 27 patients have undergone successful surgical repair 4-162 (median 19.5) weeks after initial RVOT stent implantation, 2 patients are still waiting. There were no perioperative deaths. CONCLUSIONS: Stenting of the RVOT provides a safe and effective management strategy for initial palliation in symptomatic young infants, including those patients not suitable or at higher risk for surgical therapy.

Stenting of the obstructed ductus venosus as emergency and bridging strategy in a very low birth weight infant with infradiaphragmatic total anomalous pulmonary venous connection.

A very low birth weight neonate (1.2 kg) with total anomalous pulmonary venous connection and obstructed infracardiac pulmonary venous drainage was treated by stenting of the ductus venosus via a transjugular approach. With one reintervention to dilate an in-stent stenosis, the palliative stented situation stabilized the patient for as long as three months until definitive surgical correction at a weight of 2 kg. © 2014 Wiley Periodicals, Inc.

Coil-occlusion of the left ventricle as emergency treatment in failing stage I palliation for hypoplastic left heart syndrome with sinusoids.

We report on a patient with hypoplastic left heart syndrome (HLHS), ventricular septal defects, and coronary sinusoids who suffered recurrent myocardial ischemic events that required cardiopulmonary resuscitation after stage I palliation. We identified the main reason to be a steal phenomenon of blood from the left coronary artery via the sinusoids into the rudimentary left ventricle and across the septal defects into the right ventricle. To limit this coronary steal phenomenon, we successfully performed transcatheter closure of the left ventricle with implantation of three Microplex Terumo-Coils. This led to the patient's clinical stabilization. Stage II surgery took place at the age of 5 months without difficulty. In the setting of a symptomatic neonate with HLHS and ventriculocoronary connections, embolization of the left ventricle is a feasible interventional therapy.

Successful Secondary Endovascular Intervention in Pediatric Patients with Venous Thromboembolic Events.

BACKGROUND: In the past, pediatric patients with venous thromboembolic events (VTE) were treated with low-molecular-weight heparin (LMWH) which was successful in around 70% of the cases. However, anticoagulation alone might not restore patency in all patients, and advanced therapeutic options to prevent postthrombotic syndrome are needed. During recent years, endovascular interventions have become a treatment option for pediatric patients with persistent thrombotic occlusion, not only in life- or limb-threatening VTE. METHODS: We evaluated 12 consecutive patients (11-17 years) with newly diagnosed VTE being treated at our department during the last 4 years (2017-2020). In case follow-up examination showed persistent venoocclusion under anticoagulation, patients received secondary interventional therapy like recanalization, percutaneous transluminal angioplasty with or without catheter-directed thrombolysis, and stenting. Patients with no clinical signs of venoocclusion or regredient thrombosis in imaging examination received anticoagulation alone. RESULTS: Six of 12 (50%) patients underwent catheter intervention. Median time from diagnosis to intervention was 4 months (0-12 months). Reintervention was necessary in one (8%) case and complete recanalization failed in one (8%) case. There were no major bleeding events or other major postinterventional complications, no acute or late local recurrence, and all patients reported clinical improvement after the procedure. CONCLUSION: If endovascular intervention is used in teenage patients with persistent symptomatic VTE, reduction of postthrombotic symptoms is possible, even if intervention is performed secondary to failure of anticoagulation. Multidisciplinary treatment decisions can be based on the clinical course and follow-up imaging.

A multi-center trial on efficacy and safety of the LifeTech CeraFlexTM ASD occluder for transcatheter closure in patients with secundum atrial septal defects.

Background: The last decades have brought remarkable improvements in treatment strategy and occluder modification of secundum atrial septal defect (ASD) closure. Approval, efficacy and safety of ASD closure devices have previously been demonstrated. This study investigated the clinical efficacy and safety of the LifeTech CeraFlexTM ASD occluder for interventional closure of secundum ASD with a 6-month follow-up (FU). Methods: Procedure specific data was collected on patients considered for ASD closure with the CeraFlexTM occluder between April 2016 and December 2019 in three German centers. Efficacy and safety were assessed after device closure, at discharge, and at 6-month FU. Results: The primary endpoint (successful ASD closure without severe complications) was reached by 102/103 patients (99%). Device embolization occurred in two patients (one early and one late embolization). After early snare-retrieval of an embolized device, this ASD was closed surgically and in the other patient with late device embolization the defect was closed with a larger CeraFlexTM occluder. The secondary endpoint (clincal efficacy after 6 months) was reached by 94/98 patients since new onset of arrhythmia occurred in four patients. Three patients had withdrawn their study-participation and one patient had moderate residual shunt, but not related to the occluder. Incomplete right bundle branch block (iRBBB) was seen in 31 patients. At last FU only 17 patients had remaining iRBBB documenting effective volume unloading of the right ventricle. Conclusions: Catheter interventional closure of secundum ASDs with the CeraFlexTM ASD occluder was feasible, safe and effective in this study.

A family with a new elastin gene mutation: broad clinical spectrum, including sudden cardiac death.

Supravalvular aortic stenosis is associated with the Williams-Beuren syndrome, but it also occurs in a non-syndromatic congenital form. An elastin gene mutation of chromosome 7q11.23 is responsible in both cases. The vascular features are identical. These patients have a higher risk of sudden death, particularly when undergoing diagnostic or surgical procedures. We report the account of a family with a new mutation in the elastin gene. Screening over three generations revealed eight affected individuals. The cardiac and vascular malformations ranged from mild asymptomatic supravalvular aortic stenosis and isolated dysplastic atrioventricular valves to diffuse arterial hypoplasia. Two infants presented arteries affected at multiple locations, including the left coronary artery. Both died of sudden cardiac death and myocardial ischaemia, one while under general anaesthesia for cardiac catheterisation, and the other perioperatively. We discuss the pathophysiological aspects in these patients that deserve consideration before any general anaesthesia is administered.