Risk Factors for Red Blood Cell Transfusions in Children Undergoing Cardiac Catheterization.

OBJECTIVE: To identify risk factors associated with risk of red blood cell transfusions (RBCTs) following pediatric cardiac catheterizations. STUDY DESIGN: We performed a review of all pediatric cardiac catheterizations from 2012 to 2017. The primary endpoint was RBCT within 72 hours of pediatric cardiac catheterization. Patient and procedural factors were reviewed. Generalized linear modelling was performed to describe interactions among relevant risk factors. RESULTS: In total, 831 RBCTs occurred within 72 hours of 6028 pediatric cardiac catheterizations (13.8%). Univariate analysis revealed that the prevalence of RBCT was highest among infants (37.6% incidence of RBCT) and among those with higher estimated blood loss as a percent of blood volume (P = .03). Among infants, multivariate analysis revealed that weight (OR 0.72; 95% CI 0.63-0.81), complex 2-ventricle (OR 3.14, 95% CI 2.18-4.57), and single ventricle status (OR 5.21, 95% CI 3.42-8.01) were associated with risk of RBCT. Inpatient infants from intensive care (OR 4.74; 95% CI 3.49-6.49) or stepdown units (OR 2.33; 95% CI 1.58-3.46) were at higher risk. Length of procedure (OR 2.57; 95% CI 2.03-3.26) and oxygen saturation (OR 0.98; 95% CI 0.97-0.99; P < .01) were also associated with RBCTs. CONCLUSIONS: Hospitalized infants with single ventricle or complex 2-ventricle anatomy are at highest risk of RBCT. Length of procedure, blood loss, and oxygen saturations are additional risk factors associated with RBCT. Operators should consider these factors when planning pediatric cardiac catheterizations, particularly when exposure to RBCT is undesirable.

Thromboprophylaxis strategies for children with single-ventricle circulations (superior or total cavo-pulmonary connections) after stent implantation.

OBJECTIVE: To define optimal thromboprophylaxis strategy after stent implantation in superior or total cavopulmonary connections. BACKGROUND: Stent thrombosis is a rare complication of intravascular stenting, with a perceived higher risk in single-ventricle patients. METHODS: All patients who underwent stent implantation within superior or total cavopulmonary connections (caval vein, innominate vein, Fontan, or branch pulmonary arteries) were included. Cohort was divided into aspirin therapy alone versus advanced anticoagulation, including warfarin, enoxaparin, heparin, or clopidogrel. Primary endpoint was in-stent or downstream thrombus, and secondary endpoints included bleeding complications. RESULTS: A total of 58 patients with single-ventricle circulation underwent 72 stent implantations. Of them 14 stents (19%) were implanted post-superior cavopulmonary connection and 58 (81%) post-total cavopulmonary connection. Indications for stenting included vessel/conduit stenosis (67%), external compression (18%), and thrombotic occlusion (15%). Advanced anticoagulation was prescribed for 32 (44%) patients and aspirin for 40 (56%) patients. Median follow up was 1.1 (25th-75th percentile, 0.5-2.6) years. Echocardiograms were available in 71 patients (99%), and advanced imaging in 44 patients (61%). Thrombosis was present in two patients on advanced anticoagulation (6.3%) and none noted in patients on aspirin (p = 0.187). Both patients with in-stent thrombus underwent initial stenting due to occlusive left pulmonary artery thrombus acutely post-superior cavopulmonary connection. There were seven (22%) significant bleeding complications for advanced anticoagulation and none for aspirin (p < 0.001). CONCLUSIONS: Antithrombotic strategy does not appear to affect rates of in-stent thrombus in single-ventricle circulations. Aspirin alone may be sufficient for most patients undergoing stent implantation, while pre-existing thrombus may warrant advanced anticoagulation.

Premounted stents for branch pulmonary artery stenosis in children: A short term solution.

OBJECTIVE: Define outcomes of premounted stent implantation (PMS) for branch pulmonary artery stenosis (BPAS). BACKGROUND: PMS for BPAS in children raises concern of long term viability, with limited maximal expansion. METHODS: We reviewed our cardiac database over an 11-year period ending in 2013. Primary endpoint was need for surgical stent intervention (SSI). Other endpoints included acute results and repeat interventions (RI). RESULTS: 82 PMS were implanted in 60 children for BPAS. Median weight was 6.3 (25th -75th 4.6-9.8) kg. Median stent diameter was 6 (range 4-9) mm. Acutely, vessel diameter improved from 2.0 (25th -75th 1.6-3.4) to 5.0 (25th -75th 4.2-5.9) mm (p < 0.001), pressure gradient decreased from 41 (25th -75th 29-50) to 11 (25th -75th 7-18) mmHg (n = 47, p < 0.001), RV:Ao pressure ratio decreased from 100% (25th -75th 85-110%) to 59% (25th -75th 49-74%) (n = 40, p < 0.001). Freedom from SSI was 81% at 1 year and 35% at 5 years. Freedom from RI was 50% at 1 year and 14% at 5 years. 86% of PMS underwent SSI during a concomitant planned cardiac surgery. 45% patients had stent redilation, improving stent diameter from 4.6 (25th -75th 4.1-5.4) to 5.7 (25th -75th 4.9-7) mm (p < 0.001). 1 stent (3%) was able to be fractured longitudinally. CONCLUSIONS: PMS is an effective short term solution for BPAS in children. PMS is associated with expected early need for transcatheter reintervention to accommodate for growth, but also has high rates of SSI.

Angiographic follow-up of infants and children undergoing percutaneous carotid artery interventions.

OBJECTIVE: The purpose of this study was to review the outcomes following the percutaneous carotid arterial (PCA) approach in infants and children with congenital heart disease. BACKGROUND: PCA access is becoming more commonly adopted following reports demonstrating it is a safe alternative to surgical carotid cutdown and even the femoral arterial route. However, follow-up outcomes after PCA remain unreported. METHODS: We reviewed all cases with PCA access and follow-up catheterizations which included carotid artery (CA) angiography between May 2012 until December 2016. We examined for evidence of CA stenosis at follow-up angiography and assessed any other CA complications associated with vascular access. RESULTS: There were 61 PCA catheterizations performed in 55 unique patients. Follow-up CA imaging with angiography was available in 43 patients (78%, 43/55). There was no vessel stenosis nor lumen irregularity in 28 (65%) patients. In 15 cases (35%), there was a mild degree of irregularity or narrowing by angiography (median 4.1%, range 2.3%-12.5%). Nine patients underwent repeat PCA catheterizations. Seven of these had no visible vascular stenosis on follow-up angiographic imaging, including a patient who was accessed three separate times from the CA. No statistically significant risk factors for developing mild CA stenosis were identified. CONCLUSIONS: PCA access for pediatric interventional catheterization appears to be safe with a very low rate of mild stenosis, and very few complications. Follow-up outcomes in our series are excellent, with a CA patency rate of 100%, even after multiple procedures. Mild CA stenosis was not associated with patient size or sheath introducer caliber. While the acute results from percutaneous CA catheterization have proven safe in recent literature, longer-term outcomes remain unreported. At our institution, the outcomes following percutaneous carotid access are associated with an excellent patency rate of 100%, even after multiple procedures on the same vessel. A low incidence of mild vessel stenosis can be appreciated on follow-up angiography.

Long or redundant leaflet complicating transcatheter mitral valve replacement: Case vignettes that advocate for removal or reduction of the anterior mitral leaflet.

Transcatheter mitral valve replacement (TMVR) procedures can be an alternative to surgical valve replacement for high surgical risk patients with bioprosthetic mitral valves, annuloplasty rings, or severe mitral annular calcification (MAC). TMVR can trigger acute left ventricular outflow tract (LVOT) obstruction from permanent displacement of the native anterior mitral leaflet toward the left ventricular septum, more often among patients undergoing valve-in-ring and valve-in-MAC procedures. Although acute LVOT obstruction is well described in the literature, there are important additional complications of TMVR related to the length and/or redundancy of the anterior mitral valve that have been recognized after mitral valve surgery and have not been previously reported in the setting of TMVR. These additional complications include acute mitral regurgitation secondary to prolapsing native leaflet through the TMVR, frozen TMVR leaflet secondary to overhanging native leaflet and late LVOT obstruction in the neo-LVOT secondary to long native leaflet. Preprocedural planning with imaging (echocardiography and computed tomography) and measurement of anterior mitral leaflet length is critical important in understanding the risk for these complications. As transcatheter mitral valve technology proliferates, interactions with the anterior mitral leaflet after TMVR may be more frequent than initially anticipated. We believe that there is no advantage to an intact anterior leaflet and advocate removal or reduction of the leaflet prior to TMVR. © 2017 Wiley Periodicals, Inc.

Transcatheter Tricuspid Valve-in-Valve Implantation for the Treatment of Dysfunctional Surgical Bioprosthetic Valves: An International, Multicenter Registry Study.

BACKGROUND: Off-label use of transcatheter aortic and pulmonary valve prostheses for tricuspid valve-in-valve implantation (TVIV) within dysfunctional surgical tricuspid valve (TV) bioprostheses has been described in small reports. METHODS AND RESULTS: An international, multicenter registry was developed to collect data on TVIV cases. Patient-related factors, procedural details and outcomes, and follow-up data were analyzed. Valve-in-ring or heterotopic TV implantation procedures were not included. Data were collected on 156 patients with bioprosthetic TV dysfunction who underwent catheterization with planned TVIV. The median age was 40 years, and 71% of patients were in New York Heart Association class III or IV. Among 152 patients in whom TVIV was attempted with a Melody (n=94) or Sapien (n=58) valve, implantation was successful in 150, with few serious complications. After TVIV, both the TV inflow gradient and tricuspid regurgitation grade improved significantly. During follow-up (median, 13.3 months), 22 patients died, 5 within 30 days; all 22 patients were in New York Heart Association class III or IV, and 9 were hospitalized before TVIV. There were 10 TV reinterventions, and 3 other patients had significant recurrent TV dysfunction. At follow-up, 77% of patients were in New York Heart Association class I or II (P<0.001 versus before TVIV). Outcomes did not differ according to surgical valve size or TVIV valve type. CONCLUSIONS: TVIV with commercially available transcatheter prostheses is technically and clinically successful in patients of various ages across a wide range of valve size. Although preimplantation clinical status was associated with outcome, many patients in New York Heart Association class III or IV at baseline improved. TVIV should be considered a viable option for treatment of failing TV bioprostheses.

A multicenter study of the impella device for mechanical support of the systemic circulation in pediatric and adolescent patients.

OBJECTIVES: The objective was to review the use of Impella devices (Abiomed Inc, Danvers, MA) for temporary circulatory support in pediatric and adolescent patients (age ≤ 21 yrs). BACKGROUND: Options for minimally invasive circulatory support in children are limited, and published data are confined to case reports and small case series. METHODS: This was a retrospective, multicenter review of Impella implants in pediatric and adolescent patients from 2009-15, using standardized data collection and INTERMACS definitions. RESULTS: A total of 39 implants were performed in 38 patients from 16 centers. Median age and weight were 16 yrs (4-21 yrs) and 62 kg (15-134 kg). The primary indication for implant was cardiogenic shock in 28 patients (72%). Cardiac allograft rejection, myocarditis, or cardiomyopathy were the underlying diagnosis in 23 patients (59%); 11 patients had congenital heart disease. The median duration of support was 45 hr (1-1224 hr). Indications for explant included ventricular recovery in 16 patients, transition to another device in 12, death in 5, and transplant in 1. Survival was 85% at 7 days and 68% at 30 days. Major adverse events occurred in 8 patients: hemolysis in 3, bleeding in 2, stroke in 1 (unclear if related to Impella), sepsis in 1, and critical leg ischemia in 1. An increase in aortic regurgitation was noted in three patients, with no evidence of valve injury. CONCLUSION: Temporary circulatory support with Impella devices is feasible in pediatric and adolescent patients, with acceptable risk profiles. More experience and follow up is needed to improve technical performance and patient selection. © 2017 Wiley Periodicals, Inc.

Circulatory support using the impella device in fontan patients with systemic ventricular dysfunction: A multicenter experience.

BACKGROUND: There are limited mechanical circulatory support options for patients with single ventricle (SV) anatomy. This is a multicenter, retrospective study of the Impella pump to support the systemic ventricle in a cohort of SV patients with Fontan circulation. METHODS: Patients with SV anatomy supported with an Impella device from 2012 to 2015 were included. Demographic information, indication for support, adverse events and short-term outcome data were collected. RESULTS: Ten patients were included. The median age and weight at implant was 26 years (4-38 years) and 64 kg (15-102 kg). Indications for support were systemic ventricular failure with cardiogenic shock (n = 8) or high-risk electrophysiology (EP) procedures (n = 2). The median duration of support was 49 hr (2.7-264 hr). Support was discontinued for ventricular recovery in five patients, transition to another device in two patients, completion of EP procedure in two patients and death in one patient. Survival to hospital discharge was 80%. Adverse events occurred in 4 patients. There were two cases of hemolysis, one case of increasing aortic valve insufficiency with implant and one asymptomatic access site thrombus. There were no bleeding or thromboembolic events. CONCLUSIONS: Impella devices can provide temporary support for the systemic ventricle in SV patients as a bridge to recovery or additional device. Procedural survival and adverse event profiles are favorable. © 2017 Wiley Periodicals, Inc.

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.

Safety of Magnetic Resonance Imaging After Implantation of Stainless Steel Embolization Coils.

Stainless steel embolization coils (SSEC) have been used for over four decades for vascular occlusion. Recently, the safety of these coils in a magnetic resonance environment has been called into question, with important ramifications for thousands of patients with existing coils in place. We performed a retrospective chart review at five tertiary care pediatric centers evaluating all children and young adults with implanted SSEC who underwent magnetic resonance imaging (MRI). Data reviewed included demographics, coil implantation, MRI studies, and follow-up evaluations. Complications such as heating, discomfort, or device migration were specifically sought. Two hundred and ninety-seven patients with implanted SSEC underwent 539 MRI examinations. The median age at SSEC implantation was 2.3 years (1 week-23.2 years). The MRI studies were performed a median of 7.4 years (4 days-23.1 years) after implantation. No patients experienced any reported complications associated with their MRI examinations during the study or at median follow-up post-MRI of 4.8 years (1 day-23 years). In this large, retrospective review of patients with implanted SSEC undergoing MRI, there were no reported adverse events. These findings support the recent change by Cook Medical Inc. of their standard embolization coils from a designation of magnetic resonance unsafe to conditional.

Transcatheter interventions across fresh suture lines in infants and children: an 8-year experience.

OBJECTIVES: The purpose of this study was to examine the outcomes of catheter dilation interventions in general upon surgical anastomotic sites in the immediate postoperative period. BACKGROUND: Early postoperative cardiac catheter intervention is regarded as high-risk, particularly when a dilation intervention across a fresh suture line is performed. METHODS: All catheter dilation interventions performed upon a fresh suture line within 30 days of congenital heart surgery between August 2005 and December 2013 were reviewed. Values are reported as median and interquartile range (IQR). Primary endpoint was procedural success, which was defined as an increase in vessel diameter of >75% of the adjacent normal vessel or 50% increase over pre-dilation diameter. Secondary endpoints included procedural complications and survival to hospital discharge. RESULTS: Forty-five patients, median age 0.15 years (0.03-0.51 years), weight 4.1 kg (3.1-6.4 kg), underwent 62 interventional procedures on median postoperative day 7 (3-13 days). Among the 62 dilation interventions at surgical anastomotic areas, were 30 stent and 32 balloon angioplasty procedures. There were two major complications including: arterial dissection during stent placement and a procedural mortality due to pulmonary artery avulsion during angioplasty. There were 12 deaths (27%) prior to hospital discharge. The median ratio of maximum stent diameter to stenosis diameter was 2.62 (2.27-3.73). The median ratio of maximum balloon diameter to stenosis diameter was 2.27 (1.84-2.94). Stent placement was more likely to result in procedural success (OR 2.1; 95% confidence interval 1.6-2.8). CONCLUSION: Though caution is paramount, early postoperative catheter dilation intervention across fresh suture lines can be performed safely in small, critically ill children.

Direct physician reporting is associated with reductions in radiation exposure in pediatric cardiac catheterizations.

OBJECTIVE: The objective is to quantify radiation dose in children undergoing cardiac catheterization and determine the impact of increased reporting transparency on total radiation exposure. BACKGROUND: Cardiac catheterization (cath) can result in significant radiation exposure in children. There has been growing interest in quantifying and reducing radiation exposure in pediatric cath procedures. Our center underwent a slight change in practice recently that resulted in direct physician reporting of radiation dose following every case. METHODS: We reviewed cath procedures across three different eras in four cath categories: post-heart transplant annual cath, unilateral pulmonary artery (PA) stent placement, pre-Fontan cath, and pre-Glenn cath. The eras were defined as: Era 1, 1/2009-1/2011; Era 2, 1/2011-9/2013; and Era 3, 9/2013-5/2014. In Era 3, the physician performing the cath was responsible for reporting the radiation data. RESULTS: Across the three eras, there were significant decreases in cumulative air KERMA (mGy) among all four cath categories. From Era 2 to Era 3, the greatest decreases in radiation were noted, particularly in dose area product (cGy·cm2) in the transplant annual evaluation and pre-Glenn cases. In Era 1, 2 cases (1.2%) had a frame rate reduction, while in Era 2, 22 cases (12.0%), and in Era 3, 83 cases (21.6%) had frame rate changes (P<0.01). CONCLUSIONS: Increased physician awareness of radiation exposure is associated with a significant reduction in radiation dose across a variety of cath procedures. This is seen not only by the overall reduction in radiation across case types, but also as the frame rate was more frequently changed during individual cases, indicating an important change in physician behavior and practice.

Validation of a Prescreening Program for Transcatheter Atrial Septal Defect Closure.

Prior to initiation of a formal screening program, 30 % of patients referred for device closure of an atrial septal defect (ASD) at our institution had atrial septal anatomy which precluded ASD device closure. This resulted in inefficiencies in workflow, staff utilization, and inconvenience for families. Our objective was to report our experience with an ASD prescreening evaluation/protocol and family consultation process. This is a retrospective study of pediatric patients who underwent a comprehensive ASD prescreening evaluation at Children's Healthcare of Atlanta between January 2011 and June 2013. The comprehensive prescreening process included a detailed transthoracic echocardiogram and family consultation. Upon establishing a formal prescreening process for patients with secundum ASDs, 138 patients were screened for appropriateness of ASD device closure. At time of prescreening, 40 patients (29 %) were deemed not to be suitable candidates for device ASD closure. In 9 patients (6.5 %), after discussion with the interventionalist, parents elected to pursue surgical ASD closure. A total of 78 patients (56.5 %) underwent successful transcutaneous ASD device closure. In addition, there was a significant discrepancy in the reported size of the ASD between the outside evaluation and the ASD size discovered during the prescreening process. The addition of a prescreening program for transcatheter ASD closure has decreased the incidence of unsuccessful ASD closure from 30 to 10.3 %. The use of a comprehensive evaluation process for ASD device closure improves the likelihood of successful device implantation and permits adequate preprocedural counseling for the patient and family.

A prospective observational multicenter study of balloon angioplasty for the treatment of native and recurrent coarctation of the aorta.

OBJECTIVES: Balloon angioplasty (BA) is an important treatment option for coarctation of the aorta. The congenital cardiovascular interventional study consortium (CCISC) represents a multi-institutional and multi-national effort to prospectively investigate congenital cardiac interventions. A prospective observational analysis of the efficacy and safety of balloon aortic angioplasty was conducted. METHODS: Data were collected prospectively from 36 CCISC sites from 2004 to 2012. One hundred and thirty patients underwent BA for native (n = 76) and recurrent (n = 54) coarctation. Acute, short-term, and intermediate outcomes are described for BA performed in the setting of native and recurrent coarctation of the aorta. Outcome measures included residual upper to lower extremity blood pressure gradient (ULG), use of antihypertensive medications, aortic wall injury, reobstruction, and need for reintervention. RESULTS: There was no procedural mortality. Acutely in native and recurrent coarctation, BA achieved an ULG less than 15 mm Hg in 73-80% and to less than 10 mm Hg in 54-68% of patients, respectively. At intermediate follow-up, ULG further improved, particularly for those who underwent initial reintervention for recurrent coarctation. No significant differences in aortic wall complications were seen and intervention free survival was similar for both groups. Following angioplasty, there was no significant difference in aortic wall complications; however follow up integrated imaging decreased over time. CONCLUSIONS: BA is a safe and effective treatment for coarctation of the aorta acutely and at intermediate term. Although aortic injury occurred in patients with both native and recurrent coarctation, at intermediate follow-up, aneurysm was noted more often in those with initial intervention for native coarctation.

Physician-Modified Endograft-Facilitated Transcatheter Pulmonary Valve Replacement in Large Right Ventricular Outflow Tract.

BACKGROUND: Transcatheter pulmonary valve replacement (TPVR) in patients with a congenital or acquired abnormality resulting in enlarged right ventricular outflow tract (RVOT) is challenging and may preclude treatment with dedicated devices. We describe a technique using a physician-modified endograft to facilitate TPVR. METHODS: Six patients underwent physician-modified endograft-facilitated TPVR for severe symptomatic pulmonary insufficiency with enlarged RVOT. The fenestration was created in a commercially available endograft before implantation, which was then deployed from the dominant branch pulmonary artery into the RVOT, with the fenestration aligned with the ostium of the nondominant pulmonary artery. A covered stent was placed through the fenestration into the nondominant branch pulmonary artery, and a transcatheter heart valve was deployed within the endograft at the level of the original pulmonary valve. RESULTS: Four patients had tetralogy of Fallot, 1 had pulmonary atresia, and 1 had rheumatic valve disease. The RVOT/main pulmonary artery was severely enlarged (diameter, 44.2 [43.5-50.6] mm). All patients had reduced right ventricular (RV) function and dilated RVs (RV end-diastolic volume, 314 [235-316] mL). Successful endograft, covered stent, and transcatheter heart valve deployment were achieved in all cases without stent/valve embolization, vascular complications, or bleeding complications. At 30 days, 1 patient had mild pulmonary insufficiency, while others had none. The RV size measured by echocardiography was significantly reduced after TPVR (RV area, 34.4 [baseline] versus 29.0 [pre-discharge] versus 25.3 [30 days] cm2; P=0.03). During median follow-up of 221.5 (range, 29-652) days, there were no deaths or need for pulmonary valve reintervention. One patient developed severe tricuspid regurgitation due to entrapment of the anterior tricuspid leaflet by the endograft. The patient underwent successful tricuspid replacement and resection of the offending endograft with preservation of the pulmonary valve prosthesis. CONCLUSIONS: Simple fenestration of an off-the-shelf endograft and associated covered stent placement through the fenestration allows TPVR for patients with dysfunctional native or patch-repaired pulmonary valves and RVOT enlargement.

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.).

Transcatheter Recanalization of Atretic Pulmonary Veins in Infants and Children.

BACKGROUND: Pulmonary vein stenosis is a progressive disease associated with a high rate of mortality in children. If left untreated, myofibroblastic proliferation can lead to pulmonary vein atresia (PVA). In our experience, transcatheter recanalization has emerged as a favorable interventional option. We sought to determine the acute success rate of recanalization of atretic pulmonary veins and mid-term outcomes of individual veins after recanalization. METHODS: We reviewed all patients with PVA at our institution between 2008 and 2020 diagnosed by either catheterization or cardiac computed tomography. All veins with successful recanalization were reviewed and procedural success rate and patency rate were noted. Competing risk analysis was performed to demonstrate outcomes of individual atretic veins longitudinally. RESULTS: Between 2008 and 2020, our institution diagnosed and treated 131 patients with pulmonary vein stenosis. Of these, 61 patients developed atresia of at least one pulmonary vein. In total, there were 97 atretic pulmonary veins within this group. Successful recanalization was accomplished in 47/97 (48.5%) atretic veins. No atretic pulmonary veins were successfully recanalized before 2012. The majority of veins were recanalized between 2017 and 2020-39/56 (70%). The most common intervention after recanalization was drug-eluting stent placement. At 2-year follow-up 42.6% of recanalized veins (20.6% of all atretic veins) remained patent with a median of 4 reinterventions per person. CONCLUSIONS: Transcatheter recanalization of PVA can result in successful reestablishment of flow to affected pulmonary veins in many cases. Drug-eluting stent implantation was the most common intervention performed immediately post-recanalization. Vein patency was maintained in 42.6% of patients at 2-year follow-up from recanalization with appropriate surveillance and reintervention. Overall, only a small portion of atretic pulmonary veins underwent successful recanalization with maintained vessel patency at follow-up. Irrespective of successful recanalization, there was no detectable survival difference between the more recently treated PVA cohort and non-PVA cohort.

Thrombolysis in Children: A Case Report and Review of the Literature.

Thromboembolism (TE), including venous thromboembolism (VTE), arterial TE, arterial ischemic stroke (AIS), and myocardial infarction (MI), is considered a relatively rare complication in the pediatric population. Yet, the incidence is rising, especially in hospitalized children. The vast majority of pediatric TE occurs in the setting of at least one identifiable risk factor. Most recently, acute COVID-19 and multisystem inflammatory syndrome in children (MIS-C) have demonstrated an increased risk for TE development. The mainstay for the management pediatric TE has been anticoagulation. Thrombolytic therapy is employed more frequently in adult patients with ample data supporting its use. The data for thrombolysis in pediatric patients is more limited, but the utilization of this therapy is becoming more commonplace in tertiary care pediatric hospitals. Understanding the data on thrombolysis use in pediatric TE and the involved risks is critical before initiating one of these therapies. In this paper, we present the case of an adolescent male with acute fulminant myocarditis and cardiogenic shock likely secondary to MIS-C requiring extracorporeal life support (ECLS) who developed an extensive thrombus burden that was successfully resolved utilizing four simultaneous catheter-directed thrombolysis (CDT) infusions in addition to a review of the literature on the use of thrombolytic therapy in children.

Single-Barrel, Double-Barrel, and Fenestrated Endografts to Facilitate Transcatheter Pulmonary Valve Replacement in Large RVOT.

OBJECTIVES: The aim of this study was to test the hypothesis that narrowing the landing zone using commercially available endografts would enable transcatheter pulmonary valve replacement (TPVR) using commercially available transcatheter heart valves. BACKGROUND: TPVR is challenging in an outsized native or patch-repaired right ventricular outflow tract (RVOT). Downsizing the RVOT for TPVR is currently possible only using investigational devices. In patients ineligible because of excessive RVOT size, TPVR landing zones were created using commercially available endografts. METHODS: Consecutive patients with native or patch-repaired RVOTs and high or prohibitive surgical risk were reviewed, and this report describes the authors' experience with endograft-facilitated TPVR (EF-TPVR) offered to patients ineligible for investigational or commercial devices. All EF-TPVR patients were surgery ineligible, with symptomatic, severe pulmonary insufficiency, enlarged RVOTs, and severe right ventricular (RV) enlargement (>150 ml/m2). TPVR and surgical pulmonary valve replacement (SPVR) were compared in patients with less severe RV enlargement. RESULTS: Fourteen patients had large RVOTs unsuitable for conventional TPVR; 6 patients (1 surgery ineligible) received investigational devices, and 8 otherwise ineligible patients underwent compassionate EF-TPVR (n = 5 with tetralogy of Fallot). Three strategies were applied on the basis of progressively larger RVOT size: single-barrel, in situ fenestrated, and double-barrel endografts as required to anchor 1 (single-barrel and fenestrated) or 2 (double-barrel) transcatheter heart valves. All were technically successful, without procedure-related, 30-day, or in-hospital deaths. Two late complications (stent obstruction and embolization) were treated percutaneously. One patient died of ventricular tachycardia 36 days after EF-TPVR. Compared with 48 SPVRs, RV enlargement was greater, but 30-day and 1-year mortality and readmission were no different. The mean transvalvular pressure gradient was lower after EF-TPVR (3.8 ± 0.8 mm Hg vs. 10.7 ± 4.1 mm Hg; p < 0.001; 30 days). More than mild pulmonary insufficiency was equivalent in both (EF-TPVR 0.0% [n = 0 of 8] vs. SPVR 4.3% [n = 1 of 43]; p = 1.00; 30 days). CONCLUSIONS: EF-TPVR may be an alternative for patients with pulmonic insufficiency and enlarged RVOTs ineligible for other therapies.