Surgical Debulking of Large Ventricular Fibromas in Children.

OBJECTIVE: This study aims to provide an update on the clinical presentation, diagnostic work-up, operative strategies, and mid-term outcomes in children undergoing ventricular fibroma resection. METHODS: Single-center, retrospective cohort study of patients undergoing ventricular fibroma resection between 2000 and 2023. RESULTS: Among 52 patients, median age at surgery was 2.0 years (IQR 0.8-4.6) and median tumor volume index was 69 milliliters/m2 (IQR 49-169). Tumor distorted the atrioventricular (AV) valve/subvalvar apparatus in 30 (58%) patients and abutted major epicardial coronary arteries in 41 (79%) patients. Surgery was indicated for arrythmia (n=45, 86%), symptoms (n=14, 27%), and/or hemodynamic compromise (n=11, 21%). Tumor was debulked in 34 (65%) patients, including the last 21 patients. Concomitant AV valvuloplasty was performed in 18 patients and ventricular cavity closure in 15 (29%) patients. During a median follow-up of 2.4 years (IQR 0.8-6.2), there was no mortality, cardiac arrests, heart transplants, or single ventricle palliation. The 15-year risk of reoperation and clinical ventricular tachycardia/fibrillation was 6.7% (95% CI 0-14.3%) and 2.4% (95% CI 0-7.2%), respectively. On latest imaging, pre- and post-debulking LV ejection fraction did not significantly differ (P=.069), while no patients had signs of outflow tract obstruction, inflow tract obstruction, or > moderate AV valve regurgitation. CONCLUSIONS: Large ventricular fibromas can be resected safely with appropriate surgical planning and an emphasis on debulking. Most children maintain left ventricular function and remain free of recurrent ventricular arrhythmias at follow-up. Extended follow-up is warranted to understand whether patients remain at risk for scar-based ventricular arrhythmias in the future.

Rare cardiac inflammatory pseudotumor in a toddler: Complementary roles of cardiac magnetic resonance and positron emission tomography.

We present a rare pediatric case of cardiac inflammatory pseudotumor (IPT) with a unique presentation of fever of unknown origin with markedly elevated inflammatory markers. A right atrial mass was discovered incidentally by echocardiography. The cardiac magnetic resonance (CMR) signal characteristics and mass location were not consistent with any of the common benign cardiac tumors of childhood. The presence of high signal intensity on T2 imaging and late gadolinium enhancement, in conjunction with intense metabolic activity at the mass site on positron emission tomography (PET), raised the possibility of an inflammatory or malignant mass. The diagnosis of IPT was confirmed by biopsy. Our case highlights the utility of PET imaging to confirm the inflammatory nature and extent of an IPT.

Morphology, Clinical Associations, and Pathologic Follow-up of Quadricuspid Aortic Valves in Children.

While quadricuspid morphology is commonly observed in truncal valves, quadricuspid aortic valves (QAV) are rare and their natural history is not well described. This retrospective study of 37 patients describes the diagnostic associations and morphologic variability of QAVs in children (median age at diagnosis 4.3 y IQR 0-12 y). Associated congenital heart diseases were present in 54% (most commonly tetralogy of Fallot (TOF) and valvar pulmonary stenosis). Among patients with isolated QAV, 11 had genetic syndrome and 5 had skeletal anomalies. Valve morphology was most commonly type B (41%) and A (35%; Hurvitz and Roberts). Dilated aortic root (Z ≥ 2) was present in 5 and dilated ascending aorta in 9 patients at diagnosis. All patients with type C (n = 3) and G (n = 1) had aortic dilation. At diagnosis, >mild AR was rare (n = 1), mild regurgitation was common (n = 12, 32%), >mild AS was rare (n = 2), and mild AS was uncommon (n = 4). Over a median follow-up of 3.3y (IQR 0.9-11y), progression of AR was seen in 2 patients and progression of aortic root or ascending aorta dilation (increase in Z score by ≥ 2) was seen in 5 patients. In conclusion, QAV is a rare congenital anomaly and about half of the cases are found in hearts that are otherwise structurally normal. A relatively high prevalence is seen in patients with TOF, pulmonary stenosis, skeletal deformities, and genetic syndromes. Meticulous evaluation of aortic valve morphology should be conducted on echocardiograms performed for these indications.

Design and implementation of multicenter pediatric and congenital studies with cardiovascular magnetic resonance: Big data in smaller bodies.

Cardiovascular magnetic resonance (CMR) has become the reference standard for quantitative and qualitative assessment of ventricular function, blood flow, and myocardial tissue characterization. There is a preponderance of large CMR studies and registries in adults; However, similarly powered studies are lacking for the pediatric and congenital heart disease (PCHD) population. To date, most CMR studies in children are limited to small single or multicenter studies, thereby limiting the conclusions that can be drawn. Within the PCHD CMR community, a collaborative effort has been successfully employed to recognize knowledge gaps with the aim to embolden the development and initiation of high-quality, large-scale multicenter research. In this publication, we highlight the underlying challenges and provide a practical guide toward the development of larger, multicenter initiatives focusing on PCHD populations, which can serve as a model for future multicenter efforts.

Mitral valve orifice area predicts outcome after biventricular repair in patients with hypoplastic left ventricles.

BACKGROUND: Identification of risk factors for biventricular (BiV) repair in children with hypoplastic left ventricles (HLV) has been challenging. We sought to identify preoperative cardiovascular magnetic resonance (CMR) predictors of outcome in patients with HLVs who underwent BiV repair, with a focus on the mitral valve (MV). METHODS: Single-center retrospective analysis of preoperative CMRs on patients with HLV (≤50 mL/m2) and no endocardial fibroelastosis who underwent BiV repair from 2005-2022. CMR measurements included MV orifice area in diastole. The primary composite outcome included time to death, transplant, BiV takedown, heart failure admission, left atrial decompression, or unexpected reoperation; and the secondary outcome included more than or equal to moderate mitral stenosis and/or regurgitation. RESULTS: Median follow-up was 0.7 (interquartile range 0.1, 2.2) years. Of 122 patients [59 atrioventricular canal (AVC) and 63 non-AVC] age 3 ± 2.8 years at the time of BiV repair, freedom from the primary outcome at 2 years was 53% for AVC and 69% for non-AVC (log rank p = 0.12), and freedom from the secondary outcome at 2 years was 49% for AVC and 79% for non-AVC (log rank p < 0.01). Independent predictors of primary outcome for AVC patients included MV orifice area z-score <-2 and transitional AVC; for non-AVC patients, predictors included MV orifice area z-score <-2, abnormal MV anatomy, and conal-septal ventricular septal defect. Independent predictors of secondary outcome for AVC patients included older age at surgery, transitional AVC, and transposition of the great arteries. CONCLUSION: In children with HLV, low MV orifice area and pre-existing MV pathology are risk factors for adverse outcome after BiV repair.

Ventricular dyssynchrony late after the Fontan operation is associated with decreased survival.

BACKGROUND: Ventricular dyssynchrony and its relationship to clinical outcomes is not well characterized in patients following Fontan palliation. METHODS: Single-center retrospective analysis of cardiac magnetic resonance (CMR) imaging of patients with a Fontan circulation and an age-matched healthy comparison cohort as controls. Feature tracking was performed on all slices of a ventricular short-axis cine stack. Circumferential and radial strain, strain rate, and displacement were measured; and multiple dyssynchrony metrics were calculated based on timing of these measurements (including standard deviation of time-to-peak, maximum opposing wall delay, and maximum base-to-apex delay). Primary endpoint was a composite measure including time to death, heart transplant or heart transplant listing (D/HTx). RESULTS: A total of 503 cases (15 y; IQR 10, 21) and 42 controls (16 y; IQR 11, 20) were analyzed. Compared to controls, Fontan patients had increased dyssynchrony metrics, longer QRS duration, larger ventricular volumes, and worse systolic function. Dyssynchrony metrics were higher in patients with right ventricular (RV) or mixed morphology compared to those with LV morphology. At median follow-up of 4.3 years, 11% had D/HTx. Multiple risk factors for D/HTx were identified, including RV morphology, ventricular dilation, dysfunction, QRS prolongation, and dyssynchrony. Ventricular dilation and RV morphology were independently associated with D/HTx. CONCLUSIONS: Compared to control LVs, single right and mixed morphology ventricles in the Fontan circulation exhibit a higher degree of mechanical dyssynchrony as evaluated by CMR-FT. Dyssynchrony indices correlate with ventricular size and function and are associated with death or need for heart transplantation. These data add to the growing understanding regarding factors that can be used to risk-stratify patients with the Fontan circulation.

Histopathology of resected tissue from repair of anomalous aortic origin of a coronary artery: Potential mechanism of coronary artery compression.

Objective: This study aimed to describe the histomorphologic characteristics of resected (unroofed) common wall tissue from repair of anomalous aortic origin of a coronary artery and to determine whether the histologic features correlate with clinical and imaging findings. Methods: The histology of resected tissue was analyzed and reviewed for the presence of fibrointimal hyperplasia, smooth muscle disarray, mucoid extracellular matrix accumulation, mural fibrosis, and elastic fiber disorganization and fragmentation using hematoxylin and eosin and special stains. Clinical, computed tomography imaging, and surgical data were correlated with the histopathologic findings. Results: Twenty specimens from 20 patients (age range, 7-18 years; 14 males) were analyzed. Anomalous aortic origin of a coronary artery involved the right coronary in 16 (80%), and a slit-like ostium was noted in 18 (90%). By computed tomography imaging, the median proximal coronary artery eccentricity index was 0.4 (range, 0.20-0.90). The median length of intramural course was 8.2 mm (range, 2.6-15.2 mm). The anomalous vessel was determined to be interarterial in 14 patients (93%, 15 had evaluable images). The median distance from a commissure was 2.5 mm above the sinotubular junction (STJ) (range: 2 mm below the STJ-14 mm above the STJ). Prominent histopathologic findings included elastic fiber alterations, mural fibrosis, and smooth muscle disarray. The shared wall of the aorta and intramural coronary artery is more similar to the aorta histologically. Mural fibrosis and elastic fiber abnormalities tended to be more severe in patients >10 years of age at the time of surgery, but this did not reach statistical significance. The extent of vascular changes did not appear to have a clear relationship with the imaging features. Conclusions: The findings confirm the aortic wall-like quality of the intramural segment of the coronary artery and the presence of pathologic alterations in the wall microstructure.

Cardiac magnetic resonance parameters associated with successful conversion from a single ventricular to a one-and-a-half or biventricular circulation in patients with a hypoplastic right ventricle.

BACKGROUND: Some patients with pulmonary atresia with an intact ventricular septum (PA/IVS) or a left ventricle dominant atrioventricular canal defect (LDAVC) with a hypoplastic right ventricle (RV) and univentricular (1 V) circulation may be candidates for conversion to either a complete biventricular (2 V) repair or a one-and-a-half ventricle repair (1.5 V). We sought to identify pre-operative cardiovascular magnetic resonance (CMR) findings associated with successful conversion from 1V to 1.5V or 2V circulation. METHODS: In this single center retrospective study, subjects with PA/IVS or LDAVC and no conotruncal abnormalities were included if they had a 1 V circulation at the time of CMR followed by a surgical intervention intended to convert them to a 1.5 V or 2 V circulation. Conversion failure was defined as any of the following: (1) oxygen saturation < 90% at the most recent follow-up, (2) conversion back to a 1.5 V or 1 V circulation, or (3) death. RESULTS: In the PA/IVS cohort (n = 15, median age 1.32 years), 10 patients underwent surgical conversion to a 1.5 V circulation and 5 to a 2 V circulation. In the attempted 1.5 V group, there were 2 failures, and these cases had a lower RV mass (p = 0.04). In the attempted 2 V group, there was 1 failure, and no CMR parameters were significantly different compared to the successes. Among the successful 2 V group patients, the minimum RV end-diastolic volume (EDV) was 27 ml/m2. In the LDAVC cohort (n = 15, median age 1.0 years), 1 patient underwent surgical conversion to a 1.5 V circulation and 14 patients to a 2 V circulation. In the attempted 1.5 V group, the 1 conversion was a failure and had an RV EDV of 15 ml/m2. In the attempted 2 V group, there were 2 failures, and these cases had a smaller RV:LV stroke volume ratio (p = 0.05) and a lower RV ejection fraction (p = 0.05) compared to the successes. Among the successful 2 V group patients, the minimum RV EDV was 22 ml/m2. CONCLUSIONS: We identified multiple CMR parameters associated with successful conversion from 1 V circulation to 1.5 V or 2 V circulation in patients with PA/IVS and LDAVC. This information may improve patient selection for conversion procedures and encourage larger studies to better define the role of CMR.

Multicenter research priorities in pediatric CMR: results of a collaborative wiki survey.

Multicenter studies in pediatric cardiovascular magnetic resonance (CMR) improve statistical power and generalizability. However, a structured process for identifying important research topics has not been developed. We aimed to (1) develop a list of high priority knowledge gaps, and (2) pilot the use of a wiki survey to collect a large group of responses. Knowledge gaps were defined as areas that have been either unexplored or under-explored in the research literature. High priority goals were: (1) feasible and answerable from a multicenter research study, and (2) had potential for high impact on the field of pediatric CMR. Seed ideas were contributed by a working group and imported into a pairwise wiki survey format which allows for new ideas to be uploaded and voted upon ( https://allourideas.org ). Knowledge gaps were classified into 2 categories: 'Clinical CMR Practice' (16 ideas) and 'Disease Specific Research' (22 ideas). Over a 2-month period, 3,658 votes were cast by 96 users, and 2 new ideas were introduced. The 3 highest scoring sub-topics were myocardial disorders (9 ideas), translating new technology & techniques into clinical practice (7 ideas), and normal reference values (5 ideas). The highest priority gaps reflected strengths of CMR (e.g., myocardial tissue characterization; implementation of technologic advances into clinical practice), and deficiencies in pediatrics (e.g., data on normal reference values). The wiki survey format was effective and easy to implement, and could be used for future surveys.

Insight into the Role of the Child Opportunity Index on Surgical Outcomes in Congenital Heart Disease.

OBJECTIVE: To use neighborhood-level Child Opportunity Index (COI) measures to investigate disparities in congenital heart surgery postoperative outcomes and identify potential targets for intervention. STUDY DESIGN: In this single-institution retrospective cohort study, children <18 years old who underwent cardiac surgery between 2010 and 2020 were included. Patient-level demographics and neighborhood-level COI were used as predictor variables. COI-a composite US census tract-based score measuring educational, health/environmental, and social/economic opportunities-was dichotomized as lower (<40th percentile) vs higher (≥40th percentile). Cumulative incidence of hospital discharge was compared between groups using death as a competing risk, adjusting for clinical characteristics associated with outcomes. Secondary outcomes included hospital readmission and death within 30 days. RESULTS: Among 6247 patients (55% male) with a median age of 0.8 years (IQR, 0.2-4.3), 26% had lower COI. Lower COI was associated with longer hospital lengths of stay (adjusted HR, 1.2; 95% CI, 1.1-1.2; P < .001) and an increased risk of death (adjusted OR, 2.0; 95% CI. 1.4-2.8; P < .001), but not hospital readmission (P = .6). At the neighborhood level, lacking health insurance coverage, food/housing insecurity, lower parental literacy and college attainment, and lower socioeconomic status were associated with longer hospital length of stay and increased risk of death. At the patient-level, public insurance (adjusted OR, 1.4; 95% CI, 1.0-2.0; P = .03) and caretaker Spanish language (adjusted OR 2.4; 95% CI, 1.2-4.3; P < .01) were associated with an increased risk of death. CONCLUSIONS: Lower COI is associated with longer length of stay and higher early postoperative mortality. Risk factors identified including Spanish language, food/housing insecurity, and parental literacy serve as potential intervention targets.

Computed tomography angiography (CTA) of anomalous aortic origin of a coronary artery (AAOCA): Which measurements are accurate and reliable?

BACKGROUND: The variation and accuracy of computed tomography angiography (CTA) features of anomalous aortic origin of a coronary artery (AAOCA) have not been completely characterized. We evaluated anomalous right (AAORCA) and left (AAOLCA) coronary arteries by CTA, with an emphasis on reproducibility, comparison with surgical measurements, and effect of nitroglycerin. METHODS: CTAs were interpreted for location of coronary origin & exit from the aorta, course, and dominance; minor & major diameters of the proximal & distal coronaries; shape of orifice; and intramural length. Relationships between vessel measurements, body surface area (BSA), and nitroglycerin use were evaluated. Comparisons between CTA and surgical measurements included intramural length, surgical probe size pre-intervention vs. CTA proximal AAOCA diameter, and surgical probe size post-intervention vs. CTA distal AAOCA diameter. RESULTS: Of 104 patients [81 (78%) AAORCA], all but 1 were intramural. Compared to AAOLCA, AAORCA patients were more likely to have a high origin (91% vs. 31%, p â€‹< â€‹0.01), and slit-like orifice (58% vs. 26%, p â€‹< â€‹0.01). When CTAs with nitroglycerin were compared to those without, no difference in proximal AAOCA dimensions was identified; however distal AAOCA and normal-origin coronary dimensions were larger in scans with nitroglycerin. Aside from slit-like orifice, reliability of coronary CTA measurements, including proximal AAOCA minor diameter and intramural length, was moderate to good between readers. In a subgroup of 54 patients, proximal AAOCA minor diameter and intramural length had good agreement and correlation with surgery. CONCLUSION: Proximal AAOCA dimensions and intramural length are reproducible variables. The lack of difference in proximal AAOCA dimensions with nitroglycerin may reflect abnormal vessel mechanics. Multicenter studies are an important next step in understanding the generalizability of our findings.

2 Cases of Spontaneous Coronary Artery Dissection in Neonates.

Spontaneous coronary artery dissection in infants is a rare phenomenon. We present 2 neonates with severe ventricular dysfunction due to coronary artery dissection. Neither patient had evidence of extracardiac fibromuscular dysplasia or other comorbidities that would explain the presentation. (Level of Difficulty: Advanced.).

Ventricular arrhythmias after fibroma resection: Are patients still at risk?

BACKGROUND: Ventricular fibromas frequently present with life-threatening ventricular tachycardia (VT) or ventricular fibrillation (VF) in children. The long-term risk of sustained ventricular arrhythmias after surgical resection is unknown. OBJECTIVES: The aims of this study were to quantify the VT/VF risk after surgical resection and to examine the results of early (during index surgical hospitalization) and late (≥3 months after surgery) postoperative ventricular stimulation (V-stim) studies. METHODS: We performed a retrospective cohort study of all patients with ventricular fibromas who underwent surgical resection at our institution (2000-2020). The primary outcome was defined as recurrent VT/VF ≥3 months after index surgical resection. RESULTS: Forty-six patients with a median age at surgery of 2 years (range 0.3-18.9 years) formed our study cohort. Indications for surgery included cardiac arrest in 11 (24%), sustained VT in 16 (35%), premature ventricular contractions/nonsustained VT in 10 (22%), and hemodynamic abnormalities in 9 (20%). Of the 11 patients who presented with cardiac arrest, 4 underwent pre-resection implantable cardioverter-defibrillator (ICD) implantation, all of which were explanted at the time of surgery. An early postoperative V-stim study was performed in 26 (57%) patients, and all were negative for inducible VT/VF. Of the 13 late postoperative V-stim studies, 3 were positive: 2 underwent ICD implantation and 1 was initiated on amiodarone and underwent loop recorder implantation. At the time of last follow-up (median 1.5 years; range 0.3-16.5 years), 45 (98%) were free of clinical VT/VF and no patient with an ICD has received an appropriate shock. CONCLUSION: Surgical resection of ventricular fibromas significantly reduces the risk of life-threatening arrhythmias in children; however, a small number of patients remain vulnerable.

Imaging of pediatric cardiac tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Cardiac tumors in children are rare and the majority are benign. The most common cardiac tumor in children is rhabdomyoma, usually associated with tuberous sclerosis complex. Other benign cardiac masses include fibromas, myxomas, hemangiomas, and teratomas. Primary malignant cardiac tumors are exceedingly rare, with the most common pathology being soft tissue sarcomas. This paper provides consensus-based imaging recommendations for the evaluation of patients with cardiac tumors at diagnosis and follow-up, including during and after therapy.

Tricuspid Valve Blood Cysts Mimicking Thrombus or Vegetation on Echocardiogram in a Neonate.

A 2-month-old male infant, born premature with a birth weight of 865 g, was found to have a tricuspid valve mass mimicking thrombus and vegetation by echocardiogram on the fourth day of life. The patient was treated with antibiotics and anticoagulation with no change in the size of the mass on serial follow-up echocardiography. The patient died of severe pulmonary vein stenosis and complex neurological disability. Postmortem cardiac examination revealed numerous cardiac blood cysts with two dominant ones (1.6 and 1.5 mm) on the septal leaflet of the tricuspid valve, which based on the location and position corresponded to the suspected vegetation and thrombus on imaging. Cardiac blood cysts on valve leaflets are a common incidental finding during autopsy within the first 6 months of life; however, they are rarely detected on imaging because of their minute size, often < 0.5 mm. In this case, the sizable blood cysts were thought to represent thrombus or vegetation on echocardiogram, which influenced the patient management.

Trends in surgical management of anomalous aortic origin of the coronary artery over 2 decades.

Objective: To evaluate outcomes of patients undergoing surgery for anomalous aortic origin of the coronary artery (AAOCA) at a tertiary care center and determine the influences of a coronary artery program on management strategies and outcomes. Methods: This retrospective review of consecutive surgical patients who had isolated AAOCA at a tertiary care center between August 1, 1999, and October 31, 2022, compared patient characteristics, interventional timing, and surgical strategies before and after program inception in 2018. Comparisons between time periods and anatomical subgroups were performed using Fisher exact and Wilcoxon rank-sum tests. Results: Of 149 surgical AAOCA patients, 102 (69%) had AAO of the right coronary artery. Compared with AAO of the left coronary artery (AAOLCA), AAO of the right coronary artery (AAORCA) was associated with greater athletic participation (intramural, varsity, and college-level) (74% vs 43%; P < .001) and preoperative functional imaging (72% vs 49%; P = .01), but were less likely to have ischemic changes on functional imaging (5% vs 23%; P = .03) or any postoperative complications (7% vs 19%; P = .04). Moderate or greater aortic insufficiency occurred postoperatively in 1 (1%) of AAORCA and 1 (3%) of AAOLCA patients. After the coronary artery program inception, there was an increase among patients with AAOCA undergoing preoperative computed tomography angiography (pre-2018: 39 out of 98 [40%] vs post-2018: 48 out of 51 [94%]; P < .001) and a decrease in isolated AAOCA unroofing procedures performed (30 [31%] vs 5 [10%]; P = .004). Conclusions: Surgical management of AAOCA evolved over time, and can be achieved with low instance of postoperative aortic insufficiency. Establishment of a coronary artery program has streamlined care.

Outcomes of Repair of Congenital Aortic Valve Lesions Using Autologous Pericardium vs Porcine Intestinal Submucosa.

BACKGROUND: Outcomes following congenital aortic valve (AoV) repair are plagued by progressive dysfunction of currently available leaflet substitute materials. OBJECTIVES: We compared the long-term outcomes of congenital AoV repair using porcine intestinal submucosa vs autologous pericardium (AP). METHODS: This was a single-center retrospective review of all patients who underwent congenital AoV repair with either porcine intestinal submucosa or AP from October 2009 to March 2013. The primary outcome was postdischarge (late) unplanned AoV reintervention. Secondary outcomes included number of late AoV reinterventions and a composite of at least moderate aortic regurgitation or stenosis at latest follow-up or before the first reintervention. Associations between leaflet repair material and outcomes were assessed using multivariable regression models, adjusting for prespecified patient-related and operative variables. RESULTS: Of 26 porcine intestinal submucosa and 49 AP patients who met entry criteria, the median age was 11.0 years (IQR: 4.7-16.6 years). At a median follow-up of 8.5 years (IQR: 4.4-9.6 years), 17 (65.4%) porcine intestinal submucosa and 22 (44.9%) AP patients underwent at least 1 AoV reintervention. On multivariable analysis, porcine intestinal submucosa use was significantly associated with unplanned AoV reintervention (HR: 4.6; 95% CI: 2.2-9.8; P < 0.001), number of postdischarge AoV reinterventions (incidence rate ratio: 1.7; 95% CI: 1.0-2.9; P = 0.037), and at least moderate aortic regurgitation or stenosis at latest follow-up or before the first reintervention (OR: 5.0; 95% CI: 1.2-21.0; P = 0.027). CONCLUSIONS: Aortic valvuloplasty with porcine intestinal submucosa is associated with earlier time to reintervention compared with autologous pericardium. The search for the ideal AoV leaflet repair material continues.

Early Experience With Reverse Double Switch Operation for the Borderline Left Heart.

This study reviews our early experience with the "reverse" double switch operation (R-DSO) for borderline left hearts. A retrospective review of children with borderline left hearts who underwent R-DSO between 2017 and 2021 was conducted. Patient characteristics and early hemodynamic and clinical outcomes were collected. R-DSO was performed in 8 patients with no operative or postoperative deaths; 5 underwent decompressing bidirectional Glenn. Left ventricular (LV) poor-compliance was the dominant pathophysiology. Four patients had undergone staged LV recruitment but were not candidates for anatomical biventricular circulation due to LV hypoplasia and/or diastolic dysfunction. 7/8 patients had risk factors for Fontan circulation including pulmonary vein stenosis, pulmonary hypertension, and pulmonary artery stenosis. Median age at R-DSO was 3.7 years (19 months-12 years). All patients were in sinus rhythm at discharge. At median follow-up of 15 months (57 days-4.1 years) no mortalities, reoperations or heart transplants had occurred. All patients had normal morphologic LV systolic function. In one patient, pre-existing pulmonary hypertension (HTN) resolved after R-DSO. Reinterventions included transcatheter mitral valve replacement for residual mitral stenosis and neo-pulmonary balloon valvuloplasty. In 4 patients follow-up catheterization done at a median of 519 days (320 days-4 years) demonstrated median cardiac index of 3.2 L/min/m2 (2.2-4); median sub-pulmonary left ventricular end diastolic pressure was 9 mm Hg (7-15); median inferior vena cava/baffle pressure was 8 mm Hg (7-13). R-DSO is an alternative to anatomical biventricular repair or single ventricle palliation in patients with borderline left hearts and can result in low inferior vena cava pressures and favorable early results. This approach can also relieve pulmonary HTN and allow future transplant candidacy.

Staged Ventricular Septation in Double-Inlet Ventricle - A Strategy to Avoid Fontan?

Single-stage ventricular septation for double-inlet left or right ventricle (DILV or DIRV) has historically been associated with poor outcomes. We hypothesize that staged ventricular septation may demonstrate favorable clinical outcomes to be an alternative to Fontan palliation. This single-center retrospective study reviewed patients with DILV or DIRV who underwent staged ventricular septation between 2015-2021. The strategy involves pulmonary artery banding or Norwood procedure during infancy (stage 1), followed by partial ventricular septation to anchor the septum, while maintaining systemic RV pressure to avoid septal shift (stage 2). Residual septal defects are closed with pulmonary artery band removal at stage 3. Results are reported as median (interquartile range). Twelve patients underwent partial ventricular septation. At a median follow-up time of 17 months (8-30) after stage 2, there were no interstage deaths or cardiac transplants; LV dysfunction was observed in one patient. Hemodynamic evaluation after stage 2 demonstrated median left atrial pressure of 9.5 mm Hg (8.9-11.5), cardiac index of 3.4 L/min/m2 (3.2-3.6), and RV and LV indexed end-diastolic volumes of 52 ml/m2 (41-67) and 105 ml/m2 (81-115), respectively. Five patients have progressed to stage 3; one required pacemaker for complete heart block. Unplanned reintervention was required in 4 patients after stage 1, 2 patients after stage 2, and 3 patients after stage 3. Staged ventricular septation is an alternative to single-ventricle palliation in a subset of double-inlet ventricle patients and is associated with acceptable early outcomes. Further studies are necessary to determine long-term outcomes.