Implantation of atrial flow regulator devices in patients with congenital heart disease and children with severe pulmonary hypertension or cardiomyopathy-an international multicenter case series.

Background: The Occlutech Atrial Flow Regulator (AFR) is a self-expandable double-disc nitinol device with a central fenestration. Its use has been approved in the adult population with heart failure and described for pulmonary hypertension (PH). Only case reports and small series have been published about its use in the paediatric population and for congenital heart disease (CHD). Objectives: The authors sought to investigate the feasibility, safety, and short-term follow-up of AFR implantation in patients with CHD or children with PH or cardiomyopathy. Methods: This is a multicenter retrospective study involving 10 centers worldwide. Patients of any age with CHD or patients aged < 18 years with PH or cardiomyopathy needing AFR implantation were included. Results: A total of 40 patients underwent AFR implantation. The median age of the population at the time of the procedure was 58.5 months (IQR: 31.5-142.5) and the median weight was 17 kg (IQR: 10-46). A total of 26 (65.0%) patients had CHD, nine (22.5%) children, a cardiomyopathy, and five (12.5%), a structurally normal heart. The implantation success rate was 100%. There were two early and one late device thrombosis. Two patients (5.0%) with dilated cardiomyopathy on extracorporeal membrane oxygenator (ECMO) died during the hospital stay. At a median follow-up of 330 days (IQR: 125-593), 37 (92.5%) patients were alive. At follow-up, 20 patients improved their New York Heart Association (NYHA) class, 12 patients did not change their NYHA class, and one patient with idiopathic PH worsened. Conclusions: AFR implantation in patients with CHD and children with severe PH or cardiomyopathy is promising and seems to have beneficial effects at short-term follow-up.

Retrograde Pulmonary Vein Recanalization Using Transcatheter Electrosurgery.

Transcatheter electrosurgery is a wire-based technique used to traverse or cut tissue within blood-filled spaces using alternating current delivered by guidewires or catheters. The use of transcatheter electrosurgical techniques in the pediatric population has been limited. We are reporting the first case of retrograde pulmonary vein recanalization using transcatheter electrosurgery. (Level of Difficulty: Advanced.).

Pulmonary Vein Stenosis in Children: A Programmatic Approach Employing Primary and Anatomic Therapy.

Pulmonary vein stenosis (PVS) is a difficult condition to treat due to recurrence and progression. In 2017, we developed a comprehensive PVS Program at our center to address the multidisciplinary needs of these patients. We discuss the components of our program and our approach to these patients, using a combination of primary (medical) therapy in addition to anatomic therapy to preserve vessel patency. A multidisciplinary approach to treating these challenging patients is critical.

Aortic Root Distortion During Balloon Angioplasty of Right Ventricular Outflow Tract Prior to Transcatheter Pulmonary Valve Implantation.

We describe our experience with aortic root distortion in transcatheter pulmonary valve implantation (TPVI). Aortic root distortion (AD) can be observed with balloon angioplasty of the right ventricular outflow tract (RVOT), but its long-term significance is unknown. This has been a common finding in our institution, though not fully appreciated in our early experience. Retrospective review of procedural angiograms prior to TPVI and follow up imaging was performed. Between June 2012 and October 2017, 47 patients underwent catheterization to attempt TPVI. Five patients had coronary compression which precluded TPVI (one with significant AD as well). Four patients had significant AD and did not receive TPVI. Of the remaining 38 successful TPVI, 20 had adequate imaging to assess the aortic root. Four patients had severe AD, 7 had mild AD, and 9 with no AD. Severity of AI did not correlate with degree of AD. Median follow up after TPVI was 46 months (IQR 21-67). Of the 4 patients with severe AD who received TPVI, 1 has new mild AI with 78 months follow up. Of the 18 patients who received TPVI without adequate arch imaging, 2 patients have new mild AI with 86 and 75 months follow up. AD during RVOT angioplasty is a relatively common finding. In our early experience, some patients who were retrospectively identified to have severe AD received TPVI. These patients have done well, though further data is needed before considering severe AD a benign finding.

Midterm outcomes of right ventricular outflow tract reconstruction using the Freestyle xenograft.

OBJECTIVE: Various options exist for right ventricular outflow tract (RVOT) reconstruction in congenital heart disease. The Freestyle porcine aortic root may be used but its longevity is not well defined. DESIGN: We performed a retrospective review of all non-Ross RVOT reconstructions using the Freestyle root in our institution. Survival and reintervention, either by surgery, transcatheter valve implantation, balloon valvuloplasty, or bare metal stent placement, were recorded. Factors associated with reintervention were assessed using Cox regression. RESULTS: Between January 2002 and December 2015, there were 182 patients identified. Sixteen patients were lost to follow-up and 3 patients died, unrelated to cardiac surgery. Of the remaining 163 patients, the median age was 12.2 years (interquartile range 6.4-16.4), median weight was 39.0 kg (interquartile range 19.9-59.3), and the median body surface area was 1.23 m2 (interquartile range 0.79-1.64). Ninety-three (57%) patients had tetralogy of Fallot. The median follow-up was 5.4 years (interquartile range 2.9-8 years). There were no operative or cardiac-related deaths. Thirty-eight patients (23%) required reintervention. The rate of freedom from reintervention was 93.2% (95% CI 86.7%-96.6%) at 5 years and 48.4% (95% CI 34.9%-60.6%) at 10 years. Age < 10 years, weight < 39 kg, and body surface area <1.2 m2 at the time of valve placement, as well as valve size ≤25 mm were significantly associated with need for earlier reintervention. CONCLUSIONS: The Freestyle root in the RVOT is associated with excellent survival and low midterm need for reintervention. Its longevity is comparable to published data on homografts and other bioprosthetic valves.

Outcomes of Transcatheter Tricuspid Valve-in-Valve Implantation in Patients With Ebstein Anomaly.

We sought to describe the acute results and short- to medium-term durability of transcatheter tricuspid valve-in-valve (TVIV) implantation within surgical bioprostheses among patients with Ebstein anomaly (EA). Cases were identified from a voluntary, multicenter, international registry of 29 institutions that perform TVIV. Demographic, clinical, procedural, and follow-up data were analyzed. Eighty-one patients with EA underwent TVIV from 2008 to 2016. Thirty-four patients (42%) were New York Heart Association (NYHA) class 3/4 at time of TVIV. The most common indication for TVIV was the presence of moderate or severe tricuspid regurgitation (40%). Most patients received a Melody valve (64%). TVIV was ultimately successful in all patients, and there was no procedural mortality. Four patients (5%) developed acute valve thrombosis, 4 patients (5%) developed endocarditis, and 9 patients (11%) developed valve dysfunction not related to thrombosis or endocarditis. Eight patients (10%) underwent reintervention (2 transcatheter, 6 surgical) due to thrombosis (3), endocarditis (2), other valve dysfunction (2), and patient-prosthesis mismatch without valve dysfunction (1). Among 69 patients who were alive without reintervention at latest follow-up, 96% of those with NYHA status reported were class 1/2, a significant improvement from baseline (62% NYHA class 1/2, p <0.001). In conclusion, transcatheter TVIV offers a low-risk, minimally invasive alternative to surgical tricuspid valve re-replacement in patients with EA and a failing tricuspid valve bioprosthesis.

Melody valve implantation within freestyle stentless porcine aortic heterograft.

BACKGROUND: The Melody transcatheter pulmonary valve has been implanted successfully worldwide since its first implant in 2000. The vast majority of these valves have been implanted in pulmonary homografts. In our institution, the most common valve used for pulmonary valve replacement is the Medtronic Freestyle stentless porcine aortic heterograft. OBJECTIVE: We describe our experience implanting the Melody valve within the Freestyle heterograft. METHODS: Retrospective chart review was performed. RESULTS: Between June 2012 and June 2015, 19 Melody valves were placed within Freestyle heterografts. The most common indication for intervention was pulmonary stenosis. Following pre-stent and Melody valve implantation, right ventricle-to-pulmonary artery gradient decreased from 38.1 ± 12.1 to 10 ± 4.7 mm Hg (P < 0.001), and right ventricular pressure decreased from 61.7 ± 17.8 to 35.6 ± 10.2 mm Hg (P < 0.001). Two procedural adverse events occurred. At median follow-up of 24 months (range 2-48 months), no patients had mean right ventricular outflow tract gradients >30 mm Hg or worse than mild insufficiency. No valve reinterventions have been necessary and no episodes of endocarditis have been observed. CONCLUSIONS: The Melody valve can be implanted successfully within a stentless aortic bioprosthesis with good short- and intermediate-term longevity. © 2016 Wiley Periodicals, Inc.

Percutaneous device occlusion of hepatocardiac venous collateral via left transhepatic access in a patient with heterotaxy syndrome following Fontan procedure.

Venovenous collateral vessels are a common cause for desaturation in patients who have undergone a Fontan procedure. We describe a patient with heterotaxy syndrome (leftward pointing apex) and complex single ventricle with Fontan physiology that was desaturated due to a hepatocardiac vein. The vessel was entered via a left transhepatic access and was successfully occluded using an Amplatzer Vascular Plug.

Red blood cell transfusion for infants with single-ventricle physiology.

The purpose of this study was to assess how red blood cell (RBC) transfusions impact hemodynamic parameters in infants with single-ventricle lesions. This was a retrospective chart review. The setting was a pediatric cardiac intensive care unit at a tertiary care children's hospital. Fifty-nine patients <1 year of age with single-ventricle physiology who received a blood transfusion between December 2007 and April 2009 were analyzed. They received a total of 183 transfusions. Exclusion criteria included transfusions given within 72 h of cardiac surgery or transfusions given to patients with active bleeding. There were no interventions. The study population was divided into terciles based on pretransfusion hemoglobin (Hgb) concentration. The pretransfusion Hgb concentration in group A was 7.8 to 12.3 gm/dl, in group B was 12.4 to 13.2 gm/dl, and in group C was 13.3 to 15.7 gm/dl. Heart rate, blood pressure, arterial saturation, and cerebral near-infrared spectroscopy (cNIRS) values before transfusion, as well as at 1, 2, 4, 8, and 12 h after transfusion, were collected. There was significant improvement in diastolic blood pressure, arterial saturation, and cNIRS in group A after 12 h. Transfusions given in group B also resulted in improvement in diastolic blood pressure and arterial saturation, with less robust response of cNIRS. In group C, only arterial saturation values increased significantly. RBC transfusions can improve hemodynamics and markers of oxygen delivery in infants with single-ventricle physiology, but further studies are needed to determine an optimal Hgb level in this population. Interventions to increase Hgb above this level may be of limited benefit.

Catheter-based therapy for small preterm infants with pulmonary atresia/intact ventricular septum.

Catheter-based therapy is the preferred treatment for term infants with pulmonary atresia and intact ventricular septum without right ventricular-dependent coronaries, membranous atresia with patent infundibulum, and acceptable-sized tricuspid valve. However, in smaller preterm infants, it is more difficult to determine the adequacy of the tricuspid valve and right ventricle for two-ventricle repair and there are increased procedural risks. An excellent result in a small preterm infant with pulmonary atresia and intact ventricular septum is described using the following algorithm: determination of the tricuspid/mitral annular ratio, right-sided catheter-based intervention, and a combination of transthoracic echocardiography and angiography.

Ankyrin binding mediates L1CAM interactions with static components of the cytoskeleton and inhibits retrograde movement of L1CAM on the cell surface.

The function of adhesion receptors in both cell adhesion and migration depends critically on interactions with the cytoskeleton. During cell adhesion, cytoskeletal interactions stabilize receptors to strengthen adhesive contacts. In contrast, during cell migration, adhesion proteins are believed to interact with dynamic components of the cytoskeleton, permitting the transmission of traction forces through the receptor to the extracellular environment. The L1 cell adhesion molecule (L1CAM), a member of the Ig superfamily, plays a crucial role in both the migration of neuronal growth cones and the static adhesion between neighboring axons. To understand the basis of L1CAM function in adhesion and migration, we quantified directly the diffusion characteristics of L1CAM on the upper surface of ND-7 neuroblastoma hybrid cells as an indication of receptor-cytoskeleton interactions. We find that cell surface L1CAM engages in diffusion, retrograde movement, and stationary behavior, consistent with interactions between L1CAM and two populations of cytoskeleton proteins. We provide evidence that the cytoskeletal adaptor protein ankyrin mediates stationary behavior while inhibiting the actin-dependent retrograde movement of L1CAM. Moreover, inhibitors of L1CAM-ankyrin interactions promote L1CAM-mediated axon growth. Together, these results suggest that ankyrin binding plays a crucial role in the anti-coordinate regulation of L1CAM-mediated adhesion and migration.