Calculating Relative Lung Perfusion Using Fluoroscopic Sequences and Image Analysis: The Fluoroscopic Flow Calculator.

BACKGROUND: Maldistribution of pulmonary blood flow in patients with congenital heart disease impacts exertional performance and pulmonary artery growth. Currently, measurement of relative pulmonary perfusion can only be performed outside the catheterization laboratory. We sought to develop a tool for measuring relative lung perfusion using readily available fluoroscopy sequences. METHODS: A retrospective cohort study was conducted on patients with conotruncal anomalies who underwent lung perfusion scans and subsequent cardiac catheterizations between 2011 and 2022. Inclusion criteria were nonselective angiogram of pulmonary vasculature, oblique angulation ≤20°, and an adequate view of both lung fields. A method was developed and implemented in 3D Slicer's SlicerHeart extension to calculate the amount of contrast that entered each lung field from the start of contrast injection and until the onset of levophase. The predicted perfusion distribution was compared with the measured distribution of pulmonary blood flow and evaluated for correlation, accuracy, and bias. RESULTS: In total, 32% (79/249) of screened studies met the inclusion criteria. A strong correlation between the predicted flow split and the measured flow split was found (R2=0.83; P<0.001). The median absolute error was 6%, and 72% of predictions were within 10% of the true value. Bias was not systematically worse at either extreme of the flow distribution. The prediction was found to be more accurate for either smaller and younger patients (age 0-2 years), for right ventricle injections, or when less cranial angulations were used (≤20°). In these cases (n=40), the prediction achieved R2=0.87, median absolute error of 5.5%, and 78% of predictions were within 10% of the true flow. CONCLUSIONS: The current study demonstrates the feasibility of a novel method for measuring relative lung perfusion using conventional angiograms. Real-time measurement of lung perfusion at the catheterization laboratory has the potential to reduce unnecessary testing, associated costs, and radiation exposure. Further optimization and validation is warranted.

Trends in Ductus Arteriosus Stent Versus Blalock-Taussig-Thomas Shunt Use and Comparison of Cost, Length of Stay, and Short-Term Outcomes in Neonates With Ductal-Dependent Pulmonary Blood Flow: An Observational Study Using the Pediatric Health Information Systems Database.

BACKGROUND: The modified Blalock-Taussig-Thomas shunt is the gold standard palliation for securing pulmonary blood flow in infants with ductal-dependent pulmonary blood flow. Recently, the ductus arteriosus stent (DAS) has become a viable alternative. METHODS AND RESULTS: This was a retrospective multicenter study of neonates ≤30 days undergoing DAS or Blalock-Taussig-Thomas shunt placement between January 1, 2017 and December 31, 2020 at hospitals reporting to the Pediatric Health Information Systems database. We performed generalized linear mixed-effects modeling to evaluate trends in intervention and intercenter variation, propensity score adjustment and inverse probability weighting with linear mixed-effects modeling to analyze length of stay and cost of hospitalization, and generalized linear mixed modeling to analyze differences in 30-day outcomes. There were 1874 subjects (58% male, 61% White) from 45 centers (29% DAS). Odds of DAS increased with time (odds ratio [OR] 1.23, annually, P<0.01 [95% CI, 1.10-1.38]) with significant intercenter variation (median OR, 3.81 [95% CI, 2.74-5.91]). DAS was associated with shorter hospital length of stay (ratio of geometric means, 0.76 [95% CI, 0.63-0.91]), shorter intensive care unit length of stay (ratio of geometric means, 0.77 [95% CI, 0.61-0.97]), and less expensive hospitalization (ratio of geometric means, 0.70 [95% CI, 0.56-0.87]). Intervention was not significantly associated with odds of 30-day transplant-free survival (OR,1.18 [95% CI, 0.70-1.99]) or freedom from catheter reintervention (OR, 1.02 [95% CI, 0.65-1.58]), but DAS was associated with 30-day freedom from composite adverse outcome (OR, 1.51 [95% CI, 1.11-2.05]). CONCLUSIONS: Use of DAS is increasing, but there is variability across centers. Though odds of transplant-free survival and reintervention were not significantly different after DAS, and DAS was associated with shorter length of stay and lower in-hospital costs.

Hereditary haemorrhagic telangiectasia and SMAD4 mutation in a patient with complex single ventricle heart disease.

We report a case of hypoplastic left heart syndrome and with subsequent aortopathy and then found to have hereditary haemorrhagic telangiectasia/juvenile polyposis syndrome due to a germline SMAD4 pathologic variant. The patient's staged palliation was complicated by the development of neoaortic aneurysms, arteriovenous malformations, and gastrointestinal bleeding thought to be secondary to Fontan circulation, but workup revealed a SMAD4 variant consistent with hereditary haemorrhagic telangiectasia/juvenile polyposis syndrome. This case underscores the importance of genetic modifiers in CHD, especially those with Fontan physiology.

Coil Embolization of a Ruptured Mycotic Coronary Artery Aneurysm in a Pediatric Patient.

Mycotic coronary artery aneurysms are rare but have a high risk of mortality. Traditional management is surgical, but percutaneous intervention can be performed in patients with high surgical risk. In this report, we describe a case of mycotic coronary aneurysm in a pediatric patient successfully managed with percutaneous coil embolization. (Level of Difficulty: Advanced.).

Association of Interstage Monitoring Era and Likelihood of Hemodynamic Compromise at Intervention for Recoarctation Following the Norwood Operation.

Background Intensive monitoring has been associated with a lower death rate between the Norwood operation and superior cavopulmonary connection, possibly due to early identification and effective treatment of residual anatomic lesions like recoarctation before lasting harm occurs. Methods and Results Neonates undergoing a Norwood operation and receiving interstage care at a single center between January 1, 2005, and September 18, 2020, were studied. In those with recoarctation, we evaluated association of era ([1] preinterstage monitoring, [2] a transitional phase, [3] current era) and likelihood of hemodynamic compromise (progression to moderate or greater ventricular dysfunction/atrioventricular valve regurgitation, initiation/escalation of vasoactive/respiratory support, cardiac arrest preceding catheterization, or interstage death with recoarctation on autopsy). We also analyzed whether era was associated with technical success of transcatheter recoarctation interventions, major adverse events, and transplant-free survival. A total of 483 subjects were studied, with 22% (n=106) treated for recoarctation during the interstage period. Number of catheterizations per Norwood increased (P=0.005) over the interstage eras, with no significant change in the proportion of subjects with recoarctation (P=0.36). In parallel, there was a lower likelihood of hemodynamic compromise in subjects with recoarctation that was not statistically significant (P=0.06), with a significant difference in the proportion with ventricular dysfunction at intervention (P=0.002). Rates of technical success, procedural major adverse events, and transplant-free survival did not differ (P>0.05). Conclusions Periods with interstage monitoring were associated with increased referral for catheterization but also reduced likelihood of ventricular dysfunction (and a suggestion of lower likelihood of hemodynamic compromise) in subjects with recoarctation. Further study is needed to guide optimal interstage care of this vulnerable population.

Feasibility of Digital Stethoscopes in Telecardiology Visits for Interstage Monitoring in Infants with Palliated Congenital Heart Disease.

Infants with staged surgical palliation for congenital heart disease are at high-risk for interstage morbidity and mortality. Interstage telecardiology visits (TCV) have been effective in identifying clinical concerns and preventing unnecessary emergency department visits in this high-risk population. We aimed to assess the feasibility of implementing auscultation with digital stethoscopes (DSs) during TCV and the potential impact on interstage care in our Infant Single Ventricle Monitoring & Management Program. In addition to standard home-monitoring practice for TCV, caregivers received training on use of a DS (Eko CORE attachment assembled with Classic II Infant Littman stethoscope). Sound quality of the DS and comparability to in-person auscultation were evaluated based on two providers' subjective assessment. We also evaluated provider and caregiver acceptability of the DS. From 7/2021 to 6/2022, the DS was used during 52 TCVs in 16 patients (median TCVs/patient: 3; range: 1-8), including 7 with hypoplastic left heart syndrome. Quality of heart sounds and murmur auscultation were subjectively equivalent to in-person findings with excellent inter-rater agreement (98%). All providers and caregivers reported ease of use and confidence in evaluation with the DS. In 12% (6/52) of TCVs, the DS provided additional significant information compared to a routine TCV; this expedited life-saving care in two patients. There were no missed events or deaths. Use of a DS during TCV was feasible in this fragile cohort and effective in identifying clinical concerns with no missed events. Longer term use of this technology will further establish its role in telecardiology.

Attributable mortality benefit of digoxin treatment in hypoplastic left heart syndrome after the Norwood operation: An instrumental variable-based analysis using data from the Pediatric Health Information Systems Database.

BACKGROUND: Observational studies have demonstrated an association between the use of digoxin and reduced interstage mortality after Norwood operation for hypoplastic left heart syndrome (HLHS). Digoxin use has increased significantly but remains variable between different hospitals, independent of case-mix. Instrumental variable analyses have the potential to overcome unmeasured confounding, the major limitation of previous observational studies and to generate an estimate of the attributable benefit of treatment with digoxin. METHODS: A cohort of neonates with HLHS born from January 1, 2007 to December 31, 2021 who underwent Norwood operation at Pediatric Health Information Systems Database hospitals and survived >14 days after operation were studied. Using hospital-specific, 6-month likelihood of administering digoxin as an instrumental variable, analyses adjusting for both unmeasured confounding (using the instrumental variable) and measured confounders with multivariable logistic regression were performed. RESULTS: The study population included 5,148 subjects treated at 47 hospitals of which 63% were male and 46% non-Hispanic white. Of these, 44% (n = 2,184) were prescribed digoxin. Treatment with digoxin was associated with superior 1-year transplant-free survival in unadjusted analyses (85% vs 82%, P = .02). This survival benefit persisted in an instrumental-variable analysis (OR: 0.71, 95% CI: 0.54-0.94, P = .01), which can be converted to an absolute risk reduction of 5% (number needed to treat of 20). CONCLUSIONS: In this observational study of patients with HLHS after Norwood using instrumental variable techniques, a significant benefit in 1-year transplant-free survival attributable to digoxin was demonstrated. In the absence of clinical trial data, this should encourage the use of digoxin in this vulnerable population.

Association of Home Monitoring and Unanticipated Interstage Readmissions in Infants With Hypoplastic Left Heart Syndrome.

Background The impact of home monitoring on unanticipated interstage readmissions in infants with hypoplastic left heart syndrome has not been previously studied. We sought to examine the association of our institution's Infant Single Ventricle Management and Monitoring Program (ISVMP) with readmission frequency, cumulative readmission days, and readmission illness severity and to identify patient-level risk factors for readmission. Methods and Results We performed a retrospective single-center cohort study comparing infants with hypoplastic left heart syndrome enrolled in ISVMP (December 2010-December 2019) to historical controls (January 2007-November 2010). The primary outcome was number of readmissions per interstage days. Secondary outcomes were cumulative interstage readmission days and occurrence of severe readmissions. Inverse probability weighted and multivariable generalized linear models were used to examine the association between ISVMP and the outcomes. We compared 198 infants in the ISVMP to 128 historical controls. Infants in the ISVMP had more than double the risk of interstage readmission compared with controls (adjusted incidence rate ratio, 2.38 [95% CI, 1.50-3.78]; P=0.0003). There was no difference in cumulative interstage readmission days (adjusted incidence rate ratio, 1.02 [95% CI, 0.69-1.50]; P=0.90); however, infants in the ISVMP were less likely to have severe readmissions (adjusted odds ratio, 0.28 [95% CI, 0.11-0.68]; P=0.005). Other factors independently associated with number of readmissions included residing closer to our center, younger gestational age, genetic syndrome, and discharge on exclusive enteral feeds. Conclusions Infants in the ISVMP had more frequent readmissions but comparable readmission days and fewer severe unanticipated readmissions. These findings suggest that home monitoring can reduce interstage morbidity without increasing readmission days.

Initial Experience with Telemedicine for Interstage Monitoring in Infants with Palliated Congenital Heart Disease.

Infants with staged surgical palliation for congenital heart disease are at high-risk for interstage morbidity and mortality; home monitoring programs have mitigated these risks. In 2019, we instituted telemedicine (TM) in our established Infant Single Ventricle Monitoring Program. All consecutive patients discharged following neonatal operation/intervention were monitored until subsequent stage 2 surgical palliation. We offered TM (synchronous video) visits as part of regularly scheduled follow-up, replacing at least one in-person primary care visit with a TM cardiologist visit. We tracked emergency department (ED) visits, hospitalizations, how TM identified clinical concerns, and whether use of TM prevented unnecessary ED visits or expedited in-person assessment. We assessed caregiver and clinician satisfaction. Between 8/2019 and 5/2020, we conducted 60 TM visits for 29 patients. Of 31 eligible patients, 2 families (6.9%) declined. Median monitoring time was 199 days (range 75-264) and median number of TM visits/patient was 2 (range 1-5). In 6 visits (10%), significant clinical findings were identified which avoided an ED visit. Five TM visits led to expedited outpatient assessments, of which 1 patient required hospitalization. There were no missed events or deaths. Median ED visits/patient/month were significantly lower compared to the same calendar period of the prior year (0.0 (0-2.5) vs. 0.4 (0-3.7), p = 0.0004). Caregivers and clinicians expressed high levels of satisfaction with TM. TM for this high-risk population is feasible and effective in identifying clinical concerns and preventing unnecessary ED visits. TM was particularly effective during the COVID-19 pandemic, allowing for easy adaptation of care to ensure patient safety in this fragile cohort.

Occlusion Pressure of the Thoracic Duct in Fontan Patients With Lymphatic Failure: Does Dilatation Challenge Contractility?

BACKGROUND: The Fontan circulation challenges the lymphatic system. Increasing production of lymphatic fluid and impeding lymphatic return, increased venous pressure may cause lymphatic dilatation and decrease lymphatic contractility. In-vitro studies have reported a lymphatic diameter-tension curve, with increasing passive stretch affecting the intrinsic contractile properties of each thoracic duct segment. We aimed to describe thoracic duct occlusion pressure and asses if thoracic duct dilation impairs contractility in individuals with a Fontan circulation and lymphatic failure. METHODS: Central venous pressure and thoracic duct measurements were retrospectively collected from 31 individuals with a Fontan circulation. Thoracic duct occlusion pressure was assessed during a period of external manual compression and used as an indicator of lymphatic vessel contractility. Measurements of pressure were correlated with measurements of the thoracic duct diameter in images obtained by dynamic contrast-enhanced MR lymphangiography. RESULTS: The average central venous pressure and average pressure of the thoracic duct were 17 mm Hg. During manual occlusion, the thoracic duct pressure significantly increased to 32 mm Hg. The average thoracic duct diameter was 3.3 mm. Thoracic duct diameter correlated closely with the central venous pressure. The rise in pressure following manual occlusion showed an inverse correlation with the diameter of the thoracic duct. CONCLUSION: Higher central venous pressures are associated with increasing diameters of the thoracic duct. When challenged by manual occlusion, dilated thoracic ducts display a decreased ability to increase pressure. Dilatation and a resulting decreased contractility may partly explain the challenged lymphatic system in individuals with a Fontan circulation.

Transcatheter Thoracic Duct Decompression for Multicompartment Lymphatic Failure After Fontan Palliation.

BACKGROUND: Lymphatic embolization therapy has proven effective for Fontan failure from plastic bronchitis or protein-losing enteropathy but not when multiple lymphatic compartments are involved; furthermore, embolization does not alter the underlying pathophysiology of lymphatic dysfunction. A technique for transcatheter thoracic duct decompression (TDD), rerouting the thoracic duct to the pulmonary venous atrium to treat multicompartment lymphatic failure is described and early outcomes presented. METHODS: Initially covered stents were used to channel the innominate vein flow inside of the cavopulmonary pathway into the pulmonary venous atrium. A modified approach was developed where covered stents redirected innominate vein directly to the left atrium via an extravascular course. Baseline and follow-up data on all patients undergoing TDD were reviewed. RESULTS: Twelve patients underwent TDD between March 2018 and February 2021 at a median age of 12 (range: 2-22) years. Lymphatic failure occurred in median of 3 compartments per patient (protein-losing enteropathy, ascites, pleural effusions, plastic bronchitis); 10 patients had lymphatic embolizations before TDD. TDD method was intra-Fontan tunnel in 4, direct approach in 7, and other in 1. There were no major procedural complications; 6 patients underwent subsequent procedures, most commonly to treat endoleaks. Lymphatic failure resolved in 6 patients, improved in 2, and was unchanged in 4 at 6 (range: 1-20) months follow-up. One patient died after TDD from Fontan failure. CONCLUSIONS: TDD is a promising new treatment for the failing Fontan physiology from multicompartment lymphatic failure. Additional work is needed to refine the technique and define optimal candidates.

Clinical 3D modeling to guide pediatric cardiothoracic surgery and intervention using 3D printed anatomic models, computer aided design and virtual reality.

BACKGROUND: Surgical and catheter-based interventions for congenital heart disease require precise understanding of complex anatomy. The use of three-dimensional (3D) printing and virtual reality to enhance visuospatial understanding has been well documented, but integration of these methods into routine clinical practice has not been well described. We review the growth and development of a clinical 3D modeling service to inform procedural planning within a high-volume pediatric heart center. METHODS: Clinical 3D modeling was performed using cardiac magnetic resonance (CMR) or computed tomography (CT) derived data. Image segmentation and post-processing was performed using FDA-approved software. Patient-specific anatomy was visualized using 3D printed models, digital flat screen models and virtual reality. Surgical repair options were digitally designed using proprietary and open-source computer aided design (CAD) based modeling tools. RESULTS: From 2018 to 2020 there were 112 individual 3D modeling cases performed, 16 for educational purposes and 96 clinically utilized for procedural planning. Over the 3-year period, demand for clinical modeling tripled and in 2020, 3D modeling was requested in more than one-quarter of STAT category 3, 4 and 5 cases. The most common indications for modeling were complex biventricular repair (n = 30, 31%) and repair of multiple ventricular septal defects (VSD) (n = 11, 12%). CONCLUSIONS: Using a multidisciplinary approach, clinical application of 3D modeling can be seamlessly integrated into pre-procedural care for patients with congenital heart disease. Rapid expansion and increased demand for utilization of these tools within a high-volume center demonstrate the high value conferred on these techniques by surgeons and interventionalists alike.

Influence of Antegrade Pulmonary Blood Flow on Outcomes of Superior Cavopulmonary Connection.

BACKGROUND: We sought to characterize short- and long-term outcomes after superior cavopulmonary connection (SCPC) in children eligible for inclusion of antegrade pulmonary blood flow (APBF) in the SCPC circuit, exploring whether maintaining APBF was associated with outcomes. METHODS: This was a retrospective cohort study of patients with single-ventricle heart disease and APBF who underwent SCPC at our center between January 1, 2000, and September 30, 2017. Patients were divided into 2 groups: APBF eliminated (APBF-), and APBF maintained (APBF+) at the time of SCPC. RESULTS: Of 149 patients, 108 (72.5%) were in APBF- and 41 (27.5%) were in APBF+. Of those in APBF+, 5 (12.2%) subsequently had APBF eliminated after SCPC. Patients in APBF+ had a higher prevalence of chest tube duration >10 days and underwent more interventions during the post-SCPC hospitalization (1.9% vs 12%; P = .008 for both) but had shorter surgical support times at SCPC (P < .0001). There were no differences in post-SCPC intensive care unit or hospital length of stay. During the study period, 82 patients (76%) in APBF- and 22 patients (54%) in APBF+ underwent Fontan completion. Patients in APBF+ had a greater weight gain from SCPC to Fontan (6.7 [1.8-22] kg vs 8.15 [4.4-20.6] kg; P = .012) and a shorter hospital length of stay after Fontan (9 [4-107] days vs 7.5 [4-14] days; P = .044). CONCLUSIONS: Short-term morbidity associated with maintaining APBF at the time of SCPC is modest, but longer term outcomes suggest potential benefits in those in whom APBF can be successfully maintained.

Stent Angioplasty for Post-Operative Coronary Artery Stenosis in Infants.

INTRODUCTION: While frequently performed in the adult population, percutaneous coronary artery stent angioplasty (CSA) in infants is rare. CSA in infants is challenging because of limited options in terms of appropriately sized (length and diameter) stents, concern about stenting vessels with significant growth potential and limited data regarding durability of benefit. We report a multicenter case series of infants who underwent CSA. METHODS: A multicenter, retrospective case series of infants who underwent percutaneous CSA to treat post-operative coronary artery stenoses was performed. RESULTS: Six infants from 3 institutions who underwent post-operative CSA were identified. The anatomic diagnoses were d-transposition of the great arteries in 3 cases, anomalous left coronary artery from the pulmonary artery in 2 and supravalvar aortic stenosis in 1. All infants were critically ill at the time of CSA. Diameters of coronary artery stents used ranged from 2.25 to 2.75 mm. There were no procedural complications. All stents were patent immediately after placement and the clinical condition improved or stabilized in all patients. Follow-up angiography was available for 3 patients at 4 to 16 months post-CSA, at which time 67% (2/3) remained patent. CONCLUSION: CSA is a feasible and effective therapy for critically ill infants with post-surgical coronary obstruction. Treatment appears to allow at least short-term reperfusion to facilitate recovery of ventricular function and potential development of collateral circulation when longer-term stent patency is not achieved. Longer-term stent patency and coronary artery health remain unanswered questions.

Liver lymphatic anatomy and role in systemic lymphatic disease.

OBJECTIVES: To characterize hepatic to systemic lymphatic connections in patients with systemic lymphatic disease using intra-hepatic lymphangiography and to compare outcomes after lymphatic intervention. METHODS: In this retrospective study, patients with intra-hepatic lymphangiography from May 2014 - April 2019 at our institution were included. Imaging review was performed and hepatic lymphatic connections and flow patterns were characterized. Clinical data were reviewed and comparisons between patients undergoing lymphatic intervention with or without abnormal hepatic lymphatics were performed. RESULTS: During the study period, 105 patients underwent intra-hepatic lymphangiography. Primary clinical presentation included ascites (19/105), chylothorax (27/105), plastic bronchitis (PB) (17/105), and protein losing enteropathy (PLE) (42/105). Five categories of hepatic lymphatic connections and flow patterns were identified (%): normal (25%, 26/105), hepatoperitoneal (12%, 13/105), hepatopulmonary (10.5%, 11/105), hepatomesenteric (7.5%, 8/105), and hepatoduodenal (41%, 43/105) with four patients having more than one abnormal pattern. A comparison between clinical presentation and imaging category revealed an increased likelihood of having ascites with hepatoperitoneal (p < .0001), chylothorax/PB with hepatopulmonary (p = .01), and PLE with hepatoduodenal (p < .001) connections. Seventy-six patients had a lymphatic intervention, 24% with normal, and 76% with abnormal liver lymphatics. There was no difference in length of hospital stay or mortality between the two groups, but there was a prolonged time to symptom resolution (p = .006) and persistent symptoms after 6 months (5% vs 44%, p = .002) in the group with abnormal liver lymphatics. CONCLUSION: We identified five liver lymphatic imaging categories with a substantial correlation to presenting lymphatic disease. Abnormal imaging patterns correlated with increased morbidity. Evaluation of liver lymphatics should be considered in patients with a systemic lymphatic disease if central lymphatic imaging is normal. KEY POINTS: • We identified five liver lymphatic imaging patterns: normal, hepatoperitoneal, hepatomesenteric, hepatopulmonary, and hepatoduodenal. • Imaging patterns were correlated with disease presentation (normal - chylothorax/PB, hepatoperitoneal - ascites/chylothorax, hepatopulmonary - chylothorax/PB, hepatoduodenal - PLE). • Abnormal imaging patterns correlated with increased morbidity.

Lymphatic Disorders and Management in Patients With Congenital Heart Disease.

Congenital heart disease can lead to notable lymphatic complications such as chylothorax, plastic bronchitis, protein-losing enteropathy, and ascites. Recent improvements in lymphatic imaging and the development of new lymphatic procedures can help alleviate symptoms and improve outcomes.

Post-operative Chylothorax in Patients with Repaired Transposition of the Great Arteries.

Patients with dextro-transposition of the great arteries (d-TGA) require surgical repair as neonates. These patients are at risk for post-operative chylothorax. We sought to describe the presentation, imaging, and outcomes after intervention for patients with d-TGA with post-operative chylothorax. A retrospective chart review was performed in patients with repaired d-TGA who were referred from 1/1/2013 to 4/1/2020 for evaluation of chylothorax. Patient history, lymphatic imaging, and interventional data were collected. Impact of intervention on lymphatic drainage was evaluated with a student's t-test. Eight patients met inclusion criteria for this study. Five patients had a history of central venous thrombus leading to thoracic duct outlet occlusion. Five patients underwent intervention, two were managed conservatively, and one was not a candidate for intervention. Chylothorax resolved in six patients. There was a significant difference in output from 7 days prior to first intervention (114 mL/kg/day) compared to 28 days following final intervention (27 mL/kg/day, p = 0.034). There were no procedural complications. Chylothorax in patients with repaired transposition of the great arteries is often amenable to intervention. Early surveillance and management of central venous thrombosis may reduce the burden of lymphatic disease in these patients.

Use of Virtual Reality for Hybrid Closure of Multiple Ventricular Septal Defects.

A 28-month-old girl with multiple ventricular septal defects previously underwent surgical and transcatheter attempts at repair. Three-dimensional models were created from cardiac magnetic resonance-derived images. Viewing the models in virtual reality allowed the team to precisely locate the defects and decide on a hybrid transcatheter and surgical approach to ensure successful repair. (Level of Difficulty: Advanced.).

Impact of Transcatheter Pulmonary Artery Intervention Following Superior Cavopulmonary Connection on Pulmonary Artery Growth.

INTRODUCTION: Balloon and stent angioplasty of the pulmonary arteries (PAs) are frequently performed following superior cavopulmonary connection (SCPC), not only to normalize the caliber of the affected PA but also in hopes of maximizing downstream growth over time. There are limited data on the impact on subsequent PA growth prior to total cavopulmonary connection (TCPC). METHODS: A single-center, retrospective cohort study was performed on children who underwent transcatheter (TC) PA intervention following SCPC between January 1, 2010, and December 31, 2018. Growth of treated and contralateral PAs was measured at the lobar bifurcation (distal branch PA [DBPA]) and in the proximal lower lobe (lower lobe branch [LLB]) on serial angiograms. Growth rate was evaluated using a mixed-effect model clustered by individual patient with an interaction term for treated PA and time to evaluate for differential growth rates between treated and contralateral PAs. RESULTS: Thirty-five patients underwent TC PA intervention following SCPC, at a median of 70 days (interquartile range: 19-297 days) postoperatively. Significant growth was seen at both DBPA and LLB for raw (0.8 mm/year, 95% CI: 0.6-1.0, P < .001 for both) and body surface area (BSA) adjusted measures (8.4mm/m2/year, 95% CI: 5.6-11.2, P < .001; 7.9 mm/m2/year, 95% CI: 5.5-10.2, P < .001). The growth rate of the treated vessel was not significantly different from that of the contralateral vessel at the DBPA or LLB positions for raw (P = .71, .70) or BSA-adjusted measurements (P = .86, .64). CONCLUSION: Transcatheter PA intervention was associated with normal distal PA growth rate relative to the untreated side.