Hybrid approach to pulmonary vein stenting after Fontan palliation.

Pulmonary vein stenosis is poorly tolerated in patients who have undergone Fontan palliation and typically requires surgical or transcatheter intervention. Percutaneous transcatheter approaches to intervention can be technically difficult due to challenging anatomy. A hybrid per-atrial transcatheter approach for stenting pulmonary veins provides a direct approach to the pulmonary veins and has the potential to improve safety and efficacy of this complex intervention. We describe our experience with hybrid per-atrial pulmonary vein stenting in three patients with pulmonary vein stenosis following Fontan palliation.

Update on Transcatheter Device Closure of Congenital Septal Defects.

PURPOSE OF REVIEW: The goal of this paper is to review currently available devices for closure of atrial septal defects (ASDs) and ventricular septal defects (VSDs). RECENT FINDINGS: Favorable results from the ASSURED trial resulted in FDA approval for the most recently developed device for transcatheter ASD closure in the United States. Further studies are required to assist in the development or approval of safe devices for transcatheter perimembranous VSD closure in pediatric patients. Device closure is the less invasive and preferred management option for many ASDs, with multiple studies demonstrating lower complication rates, shorter hospital stays, and lower mortality than surgical repair. Complex ASDs that make device closure more difficult include large defects, rim deficiencies, fenestrated defects, multiple defects, and the presence of pulmonary arterial hypertension. Device closure has also become an accepted alternative to surgery for some types of ventricular septal defects VSDs, though challenges and limitations remain. Future innovations including novel devices and techniques are needed to further expand on the types of defects that can be safely closed via transcatheter approach.

Hybrid transcatheter pulmonary valve replacement with a SAPIEN S3 valve after pulmonary artery banding via left lateral thoracotomy.

For many patients with repaired congenital heart disease, the need for reintervention on dysfunctional right ventricular outflow tracts is pervasive. Many such patients are poor candidates for both transcatheter pulmonary valve replacement and cardiopulmonary bypass, and hybrid surgical and transcatheter procedures have evolved to meet this need. We present two cases of hybrid pulmonary valve replacement involving pulmonary artery band placement via left anterior thoracotomy followed by transvenous placement of a SAPIEN S3 valve without prestenting. This approach avoids cardiopulmonary bypass as well as redo sternotomy and will likely see an increase in utilization in the future.

Preprocedural three-dimensional planning aids in transcatheter ductal stent placement: A single-center experience.

OBJECTIVES: Describe the use of three-dimensional (3D) patent ductus arteriosus (PDA) modeling to better define ductal anatomy to improve preprocedural planning for ductal stent placement. BACKGROUND: Ductal stenting is an alternative to surgical shunting in patients with ductal dependent pulmonary blood flow. Ductal anatomy is often complex with extreme tortuosity and risk of pulmonary artery isolation, thus increasing procedural risks. METHODS: CT angiograms were segmented to produce 3D PDA models. Ductal morphology was characterized with attention to access approach, degree of pulmonary artery offset/risk of isolation and ductal tortuosity. 3D models were retrospectively compared with biplane angiography. RESULTS: 3D modeling was performed in 12 patients with adequate image quality for complete analysis in 11; median (interquartile range) age/weight 17 days (8-20 days) and 3.1 kg (2.4-3.9 kg). The PDA was reverse oriented in nine with average length of 17.2 ± 2.5 mm and high tortuosity (mean tortuosity index 52, range 3-108). From 3D modeling, two patients were excluded from ductal stenting-extreme ductal tortuosity and threatened pulmonary artery discontinuity, respectively. Ductal stenting was successful in the remaining nine with no major procedural complications. 3D modeling predicted a successful access approach based on the aortic orientation of the ductus in all patients (five carotid, two axillary, two femoral). When comparing 2D angiography with 3D models, angiography consistently underestimated ductal length (-3.2 mm ± 1.6 mm) and tortuosity (-14.8 ± 7.2). CONCLUSIONS: 3D modeling prior to ductal stent placement for ductal dependent pulmonary blood flow is useful in procedural planning, specifically for eligibility, access approach, and accurate ductal measurements. Further studies are needed to determine if 3D planning improves procedural outcomes.

Validation and refinement of the catheterization RISk score for pediatrics (CRISP score): An analysis from the congenital cardiac interventional study consortium.

OBJECTIVES: To externally validate the CRISP score, and determine if refinements might improve clinical utility. BACKGROUND: The CRISP score estimates risk of serious adverse events (SAEs) for pediatric catheterization. METHODS: Pediatric (age < 18) procedures reported to the Congenital Cardiovascular Interventional Study Consortium registry from 05/08 to 09/17 (n = 29,830, 27 centers) were divided into a development dataset of 14,784 earlier procedures, and a validation dataset of 15,046 more recent procedures. The development dataset was used to refit the original CRISP model, and to develop a revised(r) CRISP score, consisting of entirely pre-procedurally collected data. The validation dataset was then used to compare model fit and risk prediction between CRISP, rCRISP and two existing risk scores using Akaike's (AIC), Schwarz's (BIC) Bayes Information Criteria, -log Likelihood (N2LL), area under the receiver operator curve and chi-square goodness-of-fit statistic (across 5 risk categories). RESULTS: Overall 4.31% of patients experienced at least one SAE with frequency increasing from 1.08% in CRISP category 1 to 27.34% in category 5. Both CRISP and rCRISP (entirely pre-procedural) predicted risk of SAEs well, with observed to predicted ratios ranging from 0.71 to 1.18 across the 5 risk categories. Compared to the original CRISP score, rCRISP demonstrated less optimal model fit (higher AIC, BIC, and N2LL) but similar risk prediction (C-statistic = 0.71 vs. 0.70; chi-squared statistic = 6.77 vs. 6.85). CONCLUSION: The CRISP score accurately predicts procedural risk. With minor modifications, the revised version (rCRISP) performed well with arguably greater clinical utility as an entirely preprocedural risk model.

Routine postprocedure ultrasound increases rate of detection of femoral arterial thrombosis in infants after cardiac catheterization.

OBJECTIVES: To examine the effect of implementing postcatheterization ultrasound (US) on femoral arterial thrombosis detection rates and factors associated with thrombosis in infants. BACKGROUND: Although femoral arterial thrombosis is an uncommon complication of cardiac catheterization, it can cause limb threatening complications. Previous studies assessing the utility of postprocedure US to detect thrombosis in infants have utilized US as an adjunct to standard clinical detection methods, are small scale, or include small cohorts of infants within older populations. METHODS: We reviewed institutional records of patients 0-12 months undergoing catheterization from 2007 to 2016. Demographics and procedural data were compared between the thrombosis and non-thrombosis group. Pre- and post-US groups were compared for detected thrombosis rate. Using univariate and multivariable analyses, we identified factors associated with thrombosis. RESULTS: In total, 270 patients underwent 509 catheterizations, with 40 (7.9%) documented thromboses. The rate of thrombus detection in patients younger than 6 months increased from 8.3% to 23.4% (P = 0.006) after implementing routine US. On multivariable analysis, lower weight (P < 0.001), larger arterial sheath size (P < 0.001), and longer procedure duration (P = 0.003) were independently associated with higher odds of thrombosis. CONCLUSIONS: Higher rates of femoral arterial thrombosis detection were observed since implementing an US screening program. Further studies are needed to evaluate age-related changes in hemostasis in this population and how advanced screening methods and anticoagulation protocols may help improve short-term and long-term sequelae of femoral arterial thrombosis.

Estimating radiation exposure during paediatric cardiac catheterisation: a potential for radiation reduction with air gap technique.

INTRODUCTION: The air gap technique (AGT) is an approach to radiation dose optimisation during fluoroscopy where an "air gap" is used in place of an anti-scatter grid to reduce scatter irradiation. The AGT is effective in adults but remains largely untested in children. Effects are expected to vary depending on patient size and the amount of scatter irradiation produced. METHODS: Fluoroscopy and cineangiography were performed using a Phillips Allura Fluoroscope on tissue simulation anthropomorphic phantoms representing a neonate, 5-year-old, and teenager. Monte Carlo simulations were then used to estimate effective radiation dose first using a standard recommended imaging approach and then repeated using the AGT. Objective image quality assessments were performed using an image quality phantom. RESULTS: Effective radiation doses for the neonate and 5-year-old phantom increased consistently (2-92%) when the AGT was used compared to the standard recommended imaging approaches in which the anti-scatter grid is removed at baseline. In the teenage phantom, the AGT reduced effective doses by 5-59%, with greater dose reductions for imaging across the greater thoracic dimension of lateral projection. The AGT increased geometric magnification but with no detectable change in image blur or contrast differentiation. CONCLUSIONS: The AGT is an effective approach for dose reduction in larger patients, particularly for lateral imaging. Compared to the current dose optimisation guidelines, the technique may be harmful in smaller children where scatter irradiation is minimal.

Correlation between minute carbon dioxide elimination and pulmonary blood flow in single-ventricle patients after stage 1 palliation and 2-ventricle patients with intracardiac shunts: A pilot study.

BACKGROUND: Assessment of pulmonary blood flow and cardiac output is critical in the postoperative management of patients with single-ventricle physiology or 2-ventricle physiology with intracardiac shunting. Currently, such hemodynamic data are only obtainable by invasive procedures, such as cardiac catheterization or the use of a pulmonary artery catheter. Ready availability of such information, especially if attainable noninvasively, could be a valuable addition to postoperative management. AIMS: The aim of this study was to assess the correlation between volume of CO2 elimination obtained by volumetric capnography and pulmonary blood flow in pediatric patients with single-ventricle physiology after stage 1 palliation as well as in patients with other cardiac lesions associated with intracardiac shunting. METHODS: This prospective cohort study included children with congenital or acquired heart disease who underwent cardiac catheterization as part of clinical care. Cardiac output, pulmonary blood flow, and volume of CO2 elimination were simultaneously collected. Spearman's rank correlation coefficients were used to assess correlation between measurements after controlling for minute ventilation. RESULTS: Thirty-five patients were enrolled and divided into 3 groups. Group 1 (n = 8) included single-ventricle patients after stage 1 palliation. Group 2 (n = 10) patients had structural heart disease with 2 ventricles and intracardiac shunting. Group 3 (n = 17) had structurally normal hearts. Among Group 1 patients, the correlation coefficients (R2 ) between volume of CO2 elimination and pulmonary blood flow and volume of CO2 elimination and cardiac output were 0.60 (P = .02) 95% CI [0.01-0.79] and 0.29 (P = .74) 95% CI [-0.91 - 0.86], respectively. In patients with 2 ventricles associated with intracardiac shunts (Group 2), the correlation coefficients between volume of CO2 elimination and pulmonary blood flow and volume of CO2 elimination and cardiac output were 0.86 (P = .001) 95% CI [0.53 - 0.97] and 0.73 (P = .001) 95% CI [0.29 - 0.95], respectively. Among Group 3 patients, the correlation coefficient between volume of CO2 elimination and pulmonary blood flow was 0.66 (P = .038) 95% CI [0.29 - 0.87]. CONCLUSION: Volume of CO2 elimination may be a surrogate marker of pulmonary blood flow in single-ventricle patients and patients with biventricular physiology with intracardiac shunting. Also, among patients with normal cardiac anatomy, volume of CO2 elimination may be a marker of cardiac output.

Impact of imaging approach on radiation dose and associated cancer risk in children undergoing cardiac catheterization.

OBJECTIVES: To quantify the impact of image optimization on absorbed radiation dose and associated risk in children undergoing cardiac catheterization. BACKGROUND: Various imaging and fluoroscopy system technical parameters including camera magnification, source-to-image distance, collimation, antiscatter grids, beam quality, and pulse rates, all affect radiation dose but have not been well studied in younger children. METHODS: We used anthropomorphic phantoms (ages: newborn and 5 years old) to measure surface radiation exposure from various imaging approaches and estimated absorbed organ doses and effective doses (ED) using Monte Carlo simulations. Models developed in the National Academies' Biological Effects of Ionizing Radiation VII report were used to compare an imaging protocol optimized for dose reduction versus suboptimal imaging (+20 cm source-to-image-distance, +1 magnification setting, no collimation) on lifetime attributable risk (LAR) of cancer. RESULTS: For the newborn and 5-year-old phantoms, respectively ED changes were as follows: +157% and +232% for an increase from 6-inch to 10-inch camera magnification; +61% and +59% for a 20 cm increase in source-to-image-distance; -42% and -48% with addition of 1-inch periphery collimation; -31% and -46% with removal of the antiscatter grid. Compared with an optimized protocol, suboptimal imaging increased ED by 2.75-fold (newborn) and fourfold (5 years old). Estimated cancer LAR from 30-min of posteroanterior fluoroscopy using optimized versus suboptimal imaging, respectively was 0.42% versus 1.23% (newborn female), 0.20% versus 0.53% (newborn male), 0.47% versus 1.70% (5-year-old female) and 0.16% versus 0.69% (5-year-old male). CONCLUSIONS: Radiation-related risks to children undergoing cardiac catheterization can be substantial but are markedly reduced with an optimized imaging approach. © 2016 Wiley Periodicals, Inc.

Utilizing Hybrid Techniques to Maximize Clinical Outcomes in Congenital Heart Disease.

PURPOSE OF REVIEW: The past couple of decades have brought tremendous advances to the field of pediatric and adult congenital cardiology. Recent collaborations between interventional cardiologists and cardiac surgeons have sparked novel innovative hybrid procedures that provide potentially safer, faster, and less invasive alternatives to the management of many diseases. This paper will review the most recent advances in hybrid interventions in the field of pediatric and adult congenital cardiology. RECENT FINDINGS: The earliest experiences with hybrid interventions included intraoperative stenting of pulmonary arteries and perventricular device closure of ventricular septal defects. Newer hybrid interventions have focused on a hybrid approach to stage 1 palliation for infants with hypoplastic left heart syndrome and hybrid approaches to transcatheter pulmonary valve replacement in patients of all ages. Hybrid approaches to complex congenital heart disease are important in the management of congenital heart disease offering a less invasive approach, and novel hybrid procedures will likely be a focus of future research in this field.

Post-market surveillance to detect adverse events associated with Melody® valve implantation.

OBJECTIVE: The aim of this study was to describe previously unrecognised or under-recognised adverse events associated with Melody® valve implantation. BACKGROUND: In rare diseases and conditions, it is typically not feasible to conduct large-scale safety trials before drug or device approval. Therefore, post-market surveillance mechanisms are necessary to detect rare but potentially serious adverse events. METHODS: We reviewed the United States Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database and conducted a structured literature review to evaluate adverse events associated with on- and off-label Melody® valve implantation. Adverse events were compared with those described in the prospective Investigational Device Exemption and Post-Market Approval Melody® transcatheter pulmonary valve trials. RESULTS: We identified 631 adverse events associated with "on-label" Melody® valve implants and 84 adverse events associated with "off-label" implants. The most frequent "on-label" adverse events were similar to those described in the prospective trials including stent fracture (n=210) and endocarditis (n=104). Previously unrecognised or under-recognised adverse events included stent fragment embolisation (n=5), device erosion (n=4), immediate post-implant severe valvar insufficiency (n=2), and late coronary compression (n=2 cases at 5 days and 3 months after implantation). Under-recognised adverse events associated with off-label implantation included early valve failure due to insufficiency when implanted in the tricuspid position (n=7) and embolisation with percutaneous implantation in the mitral position (n=5). CONCLUSION: Post-market passive surveillance does not demonstrate a high frequency of previously unrecognised serious adverse events with "on-label" Melody® valve implantation. Further study is needed to evaluate safety of "off-label" uses.

The impact of femoral arterial thrombosis in paediatric cardiac catheterisation: a national study.

BACKGROUND: Previous studies have identified risk factors for femoral arterial thrombosis after paediatric cardiac catheterisation, but none of them have evaluated the clinical and economic significance of this complication at the population level. Therefore, we examined the national prevalence and economic impact of femoral arterial thrombosis after cardiac catheterisation in children. METHODS: Patients⩽18 years of age who underwent cardiac catheterisation were identified in the 2003-2009 Kids' Inpatient Database. Patients were stratified by age as follows: <1 year of age or 1-18 years of age. The primary outcome was arterial thrombosis of the lower extremity during the same hospitalisation as cardiac catheterisation. Propensity score matching was used to determine the impact of femoral arterial thrombosis on hospital length of stay, cost, and mortality. RESULTS: Among the 11,497 paediatric cardiac catheterisations identified, 4558 catheterisations (39.6%) were performed in children <1 year of age. This age group experienced a higher prevalence of reported femoral arterial thrombosis, compared with children aged 1-18 years (1.3 versus 0.3%, p<0.001). After matching, femoral arterial thrombosis in children <1 year of age was associated with similar mortality (5.4 versus 1.8%, p=0.28), length of stay (8 versus 5 days, p=0.11), and total hospital cost ($27,135 versus $28,311, p=0.61), compared with absence of thrombosis. CONCLUSIONS: Femoral arterial thrombosis is especially prevalent in children <1 year of age undergoing cardiac catheterisation. Clinicians should be vigilant in monitoring femoral arterial patency in neonates and infants after cardiac catheterisation.

Transcatheter pulmonary embolectomy after fontan.

Pulmonary embolism (PE) is a significant cause of morbidity and mortality among hospitalized patients, and thrombolytics are the mainstay of treatment. However, for patients who fail or have contraindications to thrombolytic therapy, catheter-based therapies, such as the AngioVac aspiration system, have emerged as an alternative to surgical embolectomy. Here, we present the novel case of a 22 year-old woman with Fontan circulation who developed severe postpartum cardiomyopathy and a saddle PE. She failed thrombolytic therapy but underwent successful pulmonary embolectomy by AngioVac aspiration. Patients with Fontan circulation have an increased incidence of thromboembolic events, and AngioVac thrombectomy is a valuable treatment option in these complex patients.

CRISP: Catheterization RISk score for Pediatrics: A Report from the Congenital Cardiac Interventional Study Consortium (CCISC).

OBJECTIVES: We sought to develop a scoring system that predicts the risk of serious adverse events (SAE's) for individual pediatric patients undergoing cardiac catheterization procedures. BACKGROUND: Systematic assessment of risk of SAE in pediatric catheterization can be challenging in view of a wide variation in procedure and patient complexity as well as rapidly evolving technology. METHODS: A 10 component scoring system was originally developed based on expert consensus and review of the existing literature. Data from an international multi-institutional catheterization registry (CCISC) between 2008 and 2013 were used to validate this scoring system. In addition we used multivariate methods to further refine the original risk score to improve its predictive power of SAE's. RESULTS: Univariate analysis confirmed the strong correlation of each of the 10 components of the original risk score with SAE attributed to a pediatric cardiac catheterization (P < 0.001 for all variables). Multivariate analysis resulted in a modified risk score (CRISP) that corresponds to an increase in value of area under a receiver operating characteristic curve (AUC) from 0.715 to 0.741. CONCLUSION: The CRISP score predicts risk of occurrence of an SAE for individual patients undergoing pediatric cardiac catheterization procedures.

Intervention for recoarctation in the single ventricle reconstruction trial: incidence, risk, and outcomes.

BACKGROUND: Recoarctation after the Norwood procedure increases risk for mortality. The Single Ventricle Reconstruction (SVR) trial randomized subjects with a single right ventricle undergoing a Norwood procedure to a modified Blalock-Taussig shunt or a right ventricle-pulmonary artery shunt. We sought to determine the incidence of recoarctation, risk factors, and outcomes in the SVR trial. METHODS AND RESULTS: Recoarctation was defined by intervention, either catheter based or surgical. Univariate analysis and multivariable Cox proportional hazard models were performed with adjustment for center. Of the 549 SVR subjects, 97 (18%) underwent 131 interventions (92 balloon aortoplasty, 39 surgical) for recoarctation at a median age of 4.9 months (range, 1.1-10.5 months). Intervention typically occurred at pre-stage II catheterization (n=71, 54%) or at stage II surgery (n=38, 29%). In multivariable analysis, recoarctation was associated with the shunt type in place at the end of the Norwood procedure (hazard ratio, 2.0 for right ventricle-pulmonary artery shunt versus modified Blalock-Taussig shunt; P=0.02), and Norwood discharge peak echo-Doppler arch gradient (hazard ratio, 1.07 per 1 mm Hg; P<0.01). Subjects with recoarctation demonstrated comorbidities at pre-stage II evaluation, including higher pulmonary arterial pressures (15.4±3.0 versus 14.5±3.5 mm Hg; P=0.05), higher pulmonary vascular resistance (2.6±1.6 versus 2.0±1.0 Wood units·m(2); P=0.04), and increased echocardiographic volumes (end-diastolic volume, 126±39 versus 112±33 mL/BSA(1.3), where BSA is body surface area; P=0.02). There was no difference in 12-month postrandomization transplantation-free survival between those with and without recoarctation (P=0.14). CONCLUSIONS: Recoarctation is common after Norwood and contributes to pre-stage II comorbidities. Although with intervention there is no associated increase in 1-year transplantation/mortality, further evaluation is warranted to evaluate the effects of associated morbidities.

Sildenafil exposure and hemodynamic effect after Fontan surgery.

OBJECTIVE: Determine sildenafil exposure and hemodynamic effect in children after Fontan single-ventricle surgery. DESIGN: Prospective dose-escalation trial. SETTING: Single-center pediatric catheterization laboratory. PATIENTS: Nine children post Fontan single-ventricle surgical palliation and undergoing elective cardiac catheterization: median (range) age and weight, 5.2 years (2.5-9.4 yr) and 16.3 kg (9.5-28.1 kg). Five children (55%) were boys, and six of nine (67%) had a systemic right ventricle. INTERVENTIONS: Catheterization and echocardiography performed before and immediately after single-dose IV sildenafil (0.25, 0.35, or 0.45 mg/kg over 20 min). MEASUREMENTS AND MAIN RESULTS: Peak sildenafil and desmethyl sildenafil concentration, change in hemodynamic variables measured by cardiac catheterization and echocardiography. Maximum sildenafil concentrations ranged from 124 to 646 ng/mL and were above the in vitro threshold needed for 77% phosphodiesterase type-5 inhibition in eight of nine children and 90% inhibition in seven of seven children with doses more than or equal to 0.35 mg/kg. Sildenafil improved stroke volume (+22%, p = 0.05) and cardiac output (+10%, p = 0.01) with no significant change in heart rate in eight of nine children. Sildenafil also lowered systemic (-16%, p = 0.01) and pulmonary vascular resistance index in all nine children (median baseline pulmonary vascular resistance index 2.4 [range, 1.3-3.7]; decreased to 1.9 [0.8-2.7] Wood Units × m; p = 0.01) with no dose-response effect. Pulmonary arterial pressures decreased (-10%, p = 0.02) and pulmonary blood flow increased (9%, p = 0.02). There was no change in myocardial performance index and no adverse events. CONCLUSIONS: After Fontan surgery, sildenafil infusion acutely improves cardiopulmonary hemodynamics, increasing cardiac index. For the range of doses studied, exposure was within the acute safety range reported in adult subjects.

Usefulness of PREDIC3T Case Type Risk Category in the CRISP Registry.

Procedural risk in Congenital Cardiac Catheterization (PREDIC3T) was recently reported as the contemporary procedure-type risk metric by the Congenital Cardiac Catheterization Project on Outcomes (C3PO) registry. The usefulness of this metric has not been evaluated elsewhere. The CRISP registry of Congenital Cardiovascular Interventional Study Consortium (CCISC) data set was analyzed. The study period was 14 years (2009 to 2022). The primary outcome was significant adverse event (SAE). Cases were assigned to the 6 PREDIC3T risk categories. Univariate and multivariable logistic regression models were used to evaluate the association between PREDIC3T and the primary outcome. The model discriminative performance was evaluated by the c-statistic. In a total of 64,419 enrolled cases, PREDIC3T case types were assigned in 59,822 cases (93%). The frequency for PREDIC3T category was 0 = 7,494 (12.5%), 1 = 16,932 (28.3%), 2 = 17,023 (28.5%), 3 = 9,885 (16.5%), 4 = 4,403 (7.4%), and 5 = 4,085 (6.8%). SAE was observed in 2,474 cases (4.1%). The SAE rates for category were 0 = 1.0%, 1 = 2.3%, 2 = 4.0%, 3 = 6.2%, 4 = 8.2%, and 5 = 9.0%. In a multivariable model, PREDIC3T case type risk category (odds ratios for category: 0 = 0.49, 1 = 1.00, 2 = 1.40, 3 = 2.06, 4 = 2.79, and 5 = 3.15; p <0.001) were significantly associated with SAE (c-statistic of 0.707) after adjusting for age, preprocedural inotropic support and systemic illness, low systemic saturation, high pulmonary vascular resistance, and the use of general anesthesia. The PREDIC3T case type risk category was associated with the risk of SAE in the CRISP registry data set and appeared to be a useful procedural risk classification tool.

A strategy for atrial septal defect closure in small children that eliminates long-term wall erosion risk.

OBJECTIVES: To evaluate feasibility, efficacy, and safety of an approach to atrial septal defect (ASD) occlusion in children ≤20 kg that eliminates cardiac wall erosion risk. BACKGROUND: Cardiac wall erosion is a potentially catastrophic complication of ASD device closure. The HELEX Septal Occluder (HSO) is a compliant device with no reports of erosion. The HSO is technically difficult to deploy in smaller children and cannot be used to close larger defects. To eliminate wall erosion risk, we use the HSO when feasible and surgery for larger defects. METHODS: Retrospective review of ASD procedures performed in children ≤20 kg. RESULTS: Between January 2006 and January 2011, 60 children underwent ASD closure. HSO placement was successful in 32 of 34 patients, and surgical closure was successful in all of 28 patients. Surgical patients were younger (35.1 ± 12.6 vs. 47.4 ± 15.3 months, P < 0.01) and smaller (15.3 ± 3.2 vs. 12.6 ± 4.3 kg; P < 0.01) with larger ASDs (15.8 ± 4.5 vs. 9.8 ± 3.0 mm; P < 0.01). No surgical patients demonstrated residual leak. Residual leak was seen in 14 of 32 (44%) HSO patients on postprocedure day #1 and in 1 of 26 (3.8%) with ≥6 months follow-up. Indications for surgery included: deficient inferior/superior rims (n = 17), provider preference (n = 2), and HSO device not feasible (n = 9). Serious adverse events included device embolization with percutaneous retrieval (n = 1) and postpericardiotomy syndrome without intervention (n = 1). CONCLUSIONS: The HSO can be safely used in most children ≤20 kg. Our approach to ASD closure is associated with minimal morbidity and good short-term results. This approach requires no more than a 15% increase in surgical referrals and eliminates risk of cardiac wall erosion.

Sildenafil exposure and hemodynamic effect after stage II single-ventricle surgery.

OBJECTIVES: To determine sildenafil exposure and hemodynamic effect in children after stage II single-ventricle surgery. DESIGN: Prospective, dose escalation trial. SETTING: Single-center, pediatric catheterization laboratory. PATIENTS: Twelve children poststage II single-ventricle surgical palliation and undergoing elective cardiac catheterization: median age 1.9 years (range, 0.8, 4.0), weight 11 kg (8, 13), nine females, and 10 with a single right ventricle. INTERVENTIONS: Catheterization and echocardiography performed before and immediately after single-dose IV sildenafil (0.125, 0.25, 0.35, or 0.45 mg/kg over 20 min). MEASUREMENTS: Peak sildenafil and desmethyl sildenafil concentration, change in hemodynamic parameters measured by cardiac catheterization and echocardiography including indexed pulmonary vascular resistance, and myocardial performance. MAIN RESULTS: Maximum sildenafil concentrations ranged from 92 to 775 ng/mL and were above the in vitro threshold needed for 77% phosphodiesterase type 5 (PDE-5) inhibition in 80% of subjects and 90% inhibition in 80% of subjects with doses ≥0.35 mg/kg. Sildenafil lowered pulmonary vascular resistance index in all 12 subjects (median pulmonary vascular resistance index 2.2 [range, 1.6, 7.9]; decreased to 1.7 [1.2, 5.4] WU × m; p < 0.01) with no dose-response effect. Sildenafil improved pulmonary blood flow (+8% [0, 20], p = 0.04) and saturations (+2% [0, 16], p = 0.04) in those with baseline pulmonary vascular resistance index ≥ 2 WU × m (n = 7). Change in saturations correlated inversely with change in pulmonary vascular resistance index (r = 0.74, p < 0.01). Sildenafil also lowered mean blood pressure (-12% [-20, +10]; p = 0.04). There was no change in cardiac index and no effect on myocardial performance. There were no adverse events. CONCLUSIONS: Sildenafil demonstrated nonlinear exposure with high interindividual variability but was well tolerated and effectively lowered pulmonary vascular resistance index in all subjects. Sildenafil did not acutely improve myocardial performance or increase cardiac index.

Whole-Chest Three-Dimensional Modeling Aids Hybrid Pulmonary Valve Replacement Following Double Switch Operation.

The double switch operation for congenitally corrected transposition of the great arteries (CC-TGA) has been associated with high rates of reintervention, including the need for pulmonary valve replacement. Hybrid interventional approaches can avoid bypass when complex anatomy complicates traditional catheter-based approaches. We present a case of successful transcatheter pulmonary valve replacement via hybrid per-ventricular approach with pre-procedural planning aided by 3D segmentation of skeletal and cardiac anatomy in a patient with surgically corrected CC-GTA.