Outcomes of Patients Undergoing Surgery for Complete Vascular Rings.

BACKGROUND: Few studies describe outcomes after complete vascular ring surgery in a comprehensive manner. OBJECTIVES: This study sought to describe the clinical presentation, diagnostic work-up, operative approach, and outcomes in children undergoing surgery for complete vascular rings. METHODS: This single-center retrospective cohort study includes consecutive patients (January 1990 through September 2023) undergoing primary surgery for complete vascular rings, or rerepair after primary surgery elsewhere. The primary outcome of interest was complete (as distinct from partial) symptom resolution at latest clinic follow-up. Our current preference is to pursue a comprehensive initial operation including adjunctive vascular and airway procedures targeting common causes of residual aerodigestive symptoms, such as Kommerell diverticulum resection and tracheobronchopexy. Preoperative work-up routinely involved computed tomographic angiography, dynamic bronchoscopy, and laryngoscopy. RESULTS: Of 515 patients (including 39 rerepairs), the most common diagnoses were right aortic arch with aberrant left subclavian artery and left ligamentum arteriosum (n = 323, 62.7%) and double aortic arch (n = 174, 33.8%). There was no perioperative mortality. Chylothorax occurred in 28 patients (5.4%), vocal cord dysfunction in 22 patients (4.3%), and diaphragm paralysis in 2 patients (0.4%). Follow-up was available on 453 patients (88.0%) with a median duration of 3.0 years (Q1-Q3: 0.6-9.2 years). At latest clinic follow-up, 429 patients (94.7%) reported complete symptom resolution. The risk of reoperation for residual or recurrent aerodigestive symptoms was 9.6% (95% CI: 5.7%-13.5%) at 10 years and 12.4% at 20 years (95% CI: 6.9%-17.8%). CONCLUSIONS: Surgery for complete vascular rings provides good symptomatic relief with low risk of complications, whereas reoperations for aerodigestive symptoms are infrequent.

Impact of surgical strategy and postrepair transverse aortic arch size on late hypertension after coarctation repair during infancy.

BACKGROUND: Late hypertension (HTN) after coarctation of the aorta (CoA) repair contributes to higher morbidity and mortality. An association between transverse aortic arch (TAA) hypoplasia and HTN has been found, but its relationship with surgical strategy is unclear. We studied the association between late HTN and initial surgical strategy pertaining to the TAA. METHODS: We retrospectively reviewed patients who underwent surgical repair of CoA during infancy with at least 10 years of follow-up, excluding those with atypical coarctation, major associated heart defects, and residual isthmic narrowing. TAA diameter z-score immediately postrepair was measured as a marker of surgical strategy. Systemic HTN at latest follow-up was assessed using standard criteria. RESULTS: A total of 130 patients underwent surgical repair of CoA (76% via thoracotomy, 24% via sternotomy) with resection and end-to-end anastomosis (62%), extended end-to-end anastomosis (30%), subclavian flap (5%), or arch repair with patch (4%), at a median age of 14 days (interquartile range [IQR], 7-62 days). The median postrepair TAA diameter z-score was -2.04 (IQR, -2.69 to 1.24). At a mean follow-up of 17.3 years, 43 of the 130 patients (33%) developed HTN. After controlling for age at repair, sex, and presence of a genetic syndrome, HTN was not associated with immediate postrepair TAA diameter z-score (P = .41), type of surgical incision (P = .99), or type of surgical repair (P = .66). CONCLUSIONS: In patients undergoing surgical repair of CoA during infancy, late HTN was not associated with immediate postrepair TAA size or surgical strategy pertaining to the TAA. These results suggest that factors other than surgical strategy, such as differential growth of the TAA during childhood, may be important.

Ventricular Septation for Double Inlet Ventricle: Avoiding Conduction Injury.

OBJECTIVES: Although conduction location can reliably be predicted in double inlet ventricle (DIV), ventricular septation continues to carry a significant risk of CHB. This study describes our experience with ventricular septation and intraoperative conduction mapping. METHODS: Patients undergoing ventricular septation from 2017-2023 were identified. Conduction mapping was performed on the open, decompressed, beating heart to identify the His bundle. Mapped His bundle locations were compared to those predicted from MRI diagnoses by a senior pediatric cardiac electrophysiologist blinded to mapping results. RESULTS: Ventricular septation was performed in 31 patients, 25 with hypoplastic RV and 6 with hypoplastic LV. Two-stage septation was performed in 25 patients and single-stage septation in 6. Mapped was performed in the last 25 consecutive patients. Mapped conduction location was concordant with expected location in 21/22 patients with predictions. CHB requiring a permanent pacemaker occurred in 4 patients despite successful mapping, while 10 patients required other reoperations, most commonly to address residual AV valve regurgitation or subpulmonary obstruction from the VSD patch. There has been no perioperative mortality, need for single-ventricle palliation or heart transplantation. All 13 patients who have progressed to complete septation and 18 patients with interstage circulation have acceptable hemodynamics, preserved ventricular function, and no heart failure symptoms at latest follow-up. CONCLUSIONS: Ventricular septation represents an alternative to Fontan that can be performed safely in a subset of patients with acceptable early outcomes. Conduction mapping is an adjunct strategy that may add precision to the well-established rules for reliably predicting conduction location.

Operative and nonoperative outcomes in patients with trisomy 13 and 18 with congenital heart disease.

Objective: To evaluate the short- and long-term outcomes of cardiac repair versus nonoperative management in patients with trisomy 13 and trisomy 18 with congenital heart disease. Methods: An institutional review board-approved, retrospective review was undertaken to identify all patients admitted with trisomy 13/18 and congenital heart disease. Patients were divided into 2 cohorts (operated vs nonoperated) and compared. Results: Between 1985 and 2023, 62 patients (34 operated and 28 nonoperated) with trisomy 13 (n = 9) and trisomy 18 (n = 53) were identified. The operated cohort was 74% girls, underwent mainly The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery mortality category 1 procedures (n = 24 [71%]) at a median age of 2.5 months (interquartile range [IQR], 1.3-4.5 months). This compares with the nonoperative cohort where 64% (n = 18) would have undergone The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery mortality category 1 procedures if surgery would have been elected. The most common diagnosis was ventricular septal defect. Postoperative median intensive care unit stay was 6.5 days (IQR, 3.7-15 days) with a total hospital length of stay of 15 days (IQR, 11-49 days). Thirty-day postoperative survival was 94%. There were 5 in-hospital deaths in the operated and 7 in the nonoperated cohort. Median follow-up was 15.4 months (IQR, 4.3-48.7 months) for the operated and 11.2 months (IQR, 1.2-48.3 months) for the nonoperated cohorts. One-year survival was 79% operated versus 51.5% nonoperated (P < .003). Nonoperative treatment had an increased risk of mortality (hazard ratio, 3.28; 95% CI, 1.46-7.4; P = .004). Conclusions: Controversy exists regarding the role of primary cardiac repair in patients with trisomy 13/18 and congenital heart disease. Cardiac repair can be performed safely with low early mortality and operated patients had higher long-term survival compared with nonoperated in our cohort.

Reverse double switch operation for the borderline left ventricle.

OBJECTIVE(S): This study investigates outcomes of the reverse double switch operation (R-DSO) and ventricular switch, novel approaches for patients with D-looped borderline left hearts that utilize the morphologic right ventricle as the systemic ventricle and the hypoplastic left ventricle as the subpulmonary ventricle. METHODS: This retrospective review analyzed early outcomes of children who underwent R-DSO/ventricular switch at a single institution between 2015 and 2023. Our primary end points were right ventricular (RV) function and tricuspid regurgitation. Secondary outcomes included mortality, reoperation, and perioperative complications. RESULTS: Twenty-eight patients underwent either R-DSO (n = 19) or ventricular switch (n = 9). In 19 patients, a decompressing bidirectional cavopulmonary shunt was utilized, creating a reverse 1.5 switch. Median age at R-DSO/ventricular switch was 3.1 years (range, 9 months-12 years). At a median follow-up of 1.0 year (range, 38 days-7.2 years), no mortalities or heart transplants had occurred. Mild-moderate or greater RV dysfunction was detected in 4 patients, and mild-moderate or worse tricuspid regurgitation was also detected in 4 patients. Three patients required reoperations. Preoperative RV ejection fraction <55% was associated with higher incidence of postoperative RV dysfunction. CONCLUSIONS: The R-DSO/VS strategy is an alternative to single-ventricle palliation or anatomic biventricular repair in the borderline left heart. Concerns for RV dysfunction and tricuspid regurgitation mandate close monitoring. Patients with preoperative RV dysfunction may be at risk for postoperative RV dysfunction. Further studies with longer follow-up are needed to delineate outcomes in comparison to the Fontan pathway and identify optimal candidates for this novel strategy.

Thromboelastography-guided Intraoperative Platelet Transfusion in Pediatric Heart Surgery.

BACKGROUND: Postoperative bleeding is associated with significant resource use and is an important contributor to other major adverse events in pediatric patients undergoing complex cardiac surgical procedures. Thromboelastography (TEG; TEG 6S, Haemonetics) can guide perioperative blood product transfusions to reduce the risk of postoperative bleeding. This study validated the use of a previously developed TEG 6S maximum amplitude (TEG-MA)-based platelet transfusion calculator used during cardiac surgical procedures to minimize the risk of postoperative bleeding. METHODS: In this single-center retrospective study of pediatric patients (aged ≤18 years) who underwent cardiac surgical procedures requiring cardiopulmonary bypass at Boston Children's Hospital (Boston, MA) (N = 1000), the volume of platelet transfusion administered at surgical team discretion was compared with the platelet calculator-recommended platelet transfusion volume by using linear regression analysis. Associations between the adequacy of perioperative platelet transfusion and postoperative bleeding or thrombotic complications within the first 24 hours postoperatively (bleeding) and until hospital discharge (thrombosis) were evaluated by logistic regression analysis. RESULTS: Lower TEG-MA (≤45 mm) measurements after transfusion were associated with a higher risk for postoperative bleeding (odds ratio, 4.4; 95% CI, 2.6-7.4; P < .01 [significant P value <.05]). The platelet transfusion calculator-recommended platelet transfusion volume (on the basis of TEG-MA measured at the time of rewarming) demonstrated moderate correlation with the measured TEG-MA value after platelet transfusion (Pearson r = 0.7). Intraoperative volumes of platelet transfusion that failed to increase a postoperative TEG-MA of at least 45 mm significantly increased the risk for postoperative bleeding in the first 24 hours after surgical procedures (odds ratio, 3.2; 95% CI, 1.9-5.4; P < .01 [significant P value <.05]). The posttransfusion TEG-MA was not independently associated with thrombosis. CONCLUSIONS: Customizing perioperative platelet transfusion therapy by using quantitative diagnostic tests can help reduce postoperative bleeding complications.

Predictive modeling of endocardial fibroelastosis recurrence in patients with congenital heart disease.

BACKGROUND: Endocardial fibroelastosis (EFE) is a major effector in the maldevelopment of the heart in patients with congenital heart disease. Despite successful surgical removal, EFE can redevelop, but the underlying cause of EFE recurrence remains unknown. This study aimed to identify hemodynamic predictors and genetic links to epithelial/endothelial-to-mesenchymal transition (EMT/EndMT) alterations for preoperative risk assessment. METHODS: We assessed the impact of preoperative hemodynamic parameters on EFE recurrence in a cohort of 92 patients with congenital heart disease who underwent left ventricular (LV) EFE resection between January 2010 and March 2021. Additionally, whole-exome sequencing in 18 patients was used to identify rare variants (minor allele frequency <10-5) in high-expression heart (HHE) genes related to cardiac EMT/EndMT and congenital heart disease. RESULTS: EFE recurred in 55.4% of patients, within a median of 2.2 years postsurgery. Multivariable analysis revealed specific hemodynamic parameters (mitral valve inflow and area, LV filling pressure, and aortic valve gradient and diameter) as predictors, forming a predictive model with an area under the receiver operating characteristic curve of 0.782. Furthermore, 89% of the patients exhibited damaging variants in HHE genes, with 38% linked to cardiac EMT/EndMT Gene Ontology processes and 22% associated with known congenital heart disease genes. Notably, HHE genes associated with cardiac EMT/EndMT were significantly associated with faster EFE recurrence in a multivariate analysis (hazard ratio, 3.56; 95% confidence interval, 1.24-10.17; P = .018). CONCLUSIONS: These findings established a predictive scoring system using preoperative hemodynamic parameters for EFE recurrence risk assessment. Alterations in HHE genes, particularly those linked to cardiac EMT/EndMT, exacerbate the risk of recurrence.

Clinical and 2D/3D-Echo Cardiography Determinants of Mitral Valve Reoperation in Children With Congenital Mitral Valve Disease.

Background: Congenital mitral valve disease (CMVD) presents major challenges in its medical and surgical management. Objectives: The purpose of this study was to investigate the value of 3-dimensional echocardiography (3DE) and identify associations with MV reoperation in this setting. Methods: All children <18 years of age who underwent MV reconstruction for CMVD in 2002 to 2018 were included. Preoperative and postoperative 2-dimensional echocardiography (2DE) and 3DE data were collected. Competing risks and Cox regression analysis were used to identify independent associations with MV reoperation. Receiver operating characteristic and decision-tree analysis were implemented for comparison of 3DE vs 2DE. Results: A total of 206 children underwent MV reconstruction for CMVD (mitral stenosis, n = 105, mitral regurgitation [MR], n = 75; mixed disease, n = 26); 64 (31%) required MV reoperation. Variables independently associated with MV reoperation were age <1 year (HR: 2.65; 95% CI: 1.13-6.21), tethered leaflets (HR: 2.00; 95% CI: 1.05-3.82), ≥ moderate 2DE postoperative MR (HR: 4.26; 95% CI: 2.45-7.40), changes in 3D-effective orifice area (3D-EOA) and in 3D-vena contracta regurgitant area (3D-VCRA). Changes in 3D-EOA and 3D-VCRA were more strongly associated with MV reoperation than changes in mean gradients (area under the curve [AUC]: 0.847 vs AUC: 0.676, P = 0.006) and 2D-VCRA (AUC: 0.969 vs AUC: 0.720, P = 0.012), respectively. Decision-tree analysis found that a <30% increase in 3D-EOA had 80% accuracy (HR = 8.50; 95% CI: 2.9-25.1) and a <40% decrease in 3D-VCRA had 93% accuracy (HR: 22.50; 95% CI: 2.9-175) in discriminating MV reoperation for stenotic and regurgitant MV, respectively. Conclusions: Age <1 year, tethered leaflets, 2DE postoperative MR, changes in 3D-EOA and 3D-VCRA were all independently associated with MV reoperation. 3DE parameters showed a stronger association than 2DE. 3DE-based decision-tree algorithms may help prognostication and serve as a support tool for clinical decision-making.

Experience Curve With the Cone Procedure for Ebstein's Anomaly: Effect on Cost and Resource Utilization.

Background: The volume-outcome relationship is well-known in health care. The Experience Curve, initially developed by the Boston Consulting Group for manufacturing, offers insight on this relationship and has never before been applied to health care. Objectives: The purpose of this study was to determine the effect of experience on cost and resource utilization for the Cone procedure. Methods: We performed a retrospective review of patients who underwent Cone reconstruction for Ebstein's anomaly at Boston Children's Hospital between October 2010 and October 2021. Cardiopulmonary bypass time and aortic cross clamp time over time were evaluated using exponential regression to assess the surgeon-level learning curve. At the hospital level, length of stay and cost over time were assessed using exponential regression. Results: There were 115 patients included in the study. Median hospital length of stay was 7.9 days (IQR: 6.4-10.2 days) with a decline of 3.3% per year. Median intensive care unit [ICU] length of stay was 3.2 days (IQR: 2-5.7 days) with a decline of 10.5% per year. Adjusted direct costs indexed to 2020 prices fell by 4% per year. There was no statistically significant change in cardiopulmonary bypass or aortic cross clamp time. In mediation analysis, the reduction in cost was completely accounted for in the decline in ICU length of stay. ICU length of stay was correlated with duration of intubation. Conclusions: Increasing familiarity with Ebstein's anomaly and Cone reconstruction led to a reduction in resource utilization.

Preoperative Echocardiographically Derived Mean dP/dTic Predicts Early Post-operative Dysfunction in Children Undergoing Mitral Valve Surgery.

Mean dP/dtic is a quantitative measurement of ventricular function that can be obtained noninvasively by echocardiography. In adults with mitral regurgitation (MR), it has been shown to be a more sensitive predictor of postoperative left ventricular ejection fraction (EF). The utility of dP/dtic in pediatric congenital heart diseases with MR has been underexplored. Patients (0 to ≤ 19 years) with MR who underwent mitral valve (MV) repair or replacement from 2015 to 2021 were included. Echocardiographically derived mean dP/dtic, Tei index, and EF were used to assess and compare ventricular function prior to, shortly after, and late after MV surgery. Study cohort included 61 patients (age 4.5 [IQR 0.14, 18.7] years, 89% MV repair, 11% MV replacement). Median time intervals between surgery and preoperative, early postoperative, and late postoperative echocardiograms were 6 days, 6 days, and 350 days, respectively. Median EF was 62% (z-score - 0.40) preoperatively, 56% (z-score - 1.40) early postoperatively, and 61% (z-score - 0.60) late postoperatively. Median dP/dtic was 1393 (IQR 1029, 1775) mmHg/s preoperatively, 1178 (IQR 886, 1946) mmHg/s early postoperatively, and 1270 (IQR 791, 1765) mmHg/s late postoperatively. Preoperative median dP/dtic correlated with early and late postoperative EF. Preoperative EF was not significantly correlated with early postoperative EF, but was correlated with late postoperative EF. Mitral valve intervention in pediatric patients is associated with an initial decline but subsequent recovery of systolic function. Non-invasively derived mean dP/dtic may offer advantages over other preoperative echocardiographic indices to predict postoperative systolic function.

Executive Summary: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE (PEACE) Consensus Conference.

OBJECTIVES: To present recommendations and consensus statements with supporting literature for the clinical management of neonates and children supported with extracorporeal membrane oxygenation (ECMO) from the Pediatric ECMO Anticoagulation CollaborativE (PEACE) consensus conference. DATA SOURCES: Systematic review was performed using PubMed, Embase, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021, followed by serial meetings of international, interprofessional experts in the management ECMO for critically ill children. STUDY SELECTION: The management of ECMO anticoagulation for critically ill children. DATA EXTRACTION: Within each of eight subgroup, two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts. DATA SYNTHESIS: A systematic review was conducted using MEDLINE, Embase, and Cochrane Library databases, from January 1988 to May 2021. Each panel developed evidence-based and, when evidence was insufficient, expert-based statements for the clinical management of anticoagulation for children supported with ECMO. These statements were reviewed and ratified by 48 PEACE experts. Consensus was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed 23 recommendations, 52 expert consensus statements, and 16 good practice statements covering the management of ECMO anticoagulation in three broad categories: general care and monitoring; perioperative care; and nonprocedural bleeding or thrombosis. Gaps in knowledge and research priorities were identified, along with three research focused good practice statements. CONCLUSIONS: The 91 statements focused on clinical care will form the basis for standardization and future clinical trials.

Anticoagulation Monitoring and Targets: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference.

OBJECTIVES: To derive systematic-review informed, modified Delphi consensus regarding anticoagulation monitoring assays and target levels in pediatric extracorporeal membrane oxygenation (ECMO) for the Pediatric ECMO Anticoagulation CollaborativE. DATA SOURCES: A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021. STUDY SELECTION: Anticoagulation monitoring of pediatric patients on ECMO. DATA EXTRACTION: Two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts. Evidence tables were constructed using a standardized data extraction form. DATA SYNTHESIS: Risk of bias was assessed using the Quality in Prognosis Studies tool or the revised Cochrane risk of bias for randomized trials, as appropriate and the evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for clinical recommendations focused on anticoagulation monitoring and targets, using a web-based modified Delphi process to build consensus (defined as > 80% agreement). One weak recommendation, two consensus statements, and three good practice statements were developed and, in all, agreement greater than 80% was reached. We also derived some resources for anticoagulation monitoring for ECMO clinician use at the bedside. CONCLUSIONS: There is insufficient evidence to formulate optimal anticoagulation monitoring during pediatric ECMO, but we propose one recommendation, two consensus and three good practice statements. Overall, the available pediatric evidence is poor and significant gaps exist in the literature.

Management of Extracorporeal Membrane Oxygenation Anticoagulation in the Perioperative Period: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference.

OBJECTIVES: To derive systematic review-informed, modified Delphi consensus regarding the management of children on extracorporeal membrane oxygenation (ECMO) undergoing invasive procedures or interventions developed by the Pediatric Anticoagulation on ECMO CollaborativE (PEACE) Consensus Conference. DATA SOURCES: A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021. STUDY SELECTION: ECMO anticoagulation and hemostasis management in the perioperative period and during procedures. DATA EXTRACTION: Two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts. Seventeen references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form. DATA SYNTHESIS: Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for the management of bleeding and thrombotic complications in pediatric ECMO patients. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. Four good practice statements, 7 recommendations, and 18 consensus statements are presented. CONCLUSIONS: Although agreement among experts was strong, important future research is required in this population for evidence-informed recommendations.

Perioperative Hyper-coagulation and Thrombosis: Cost Analysis After Congenital Heart Surgery.

Thrombosis, a major adverse event of congenital heart surgery, has been associated with poor outcomes. We hypothesized that in CHD patients undergoing cardiac surgery, increased perioperative use of pro-coagulant products may be associated with postoperative thrombosis in the setting of hyperfibrinogenemia, leading to greater hospital and blood product costs. Single-center retrospective study. Data from Boston Children's Hospital's electronic health record database was used in this study. All patients undergoing congenital heart surgery between 2015 and 2018 with postoperative fibrinogen levels above 400 mg/dl were reviewed. Of 334 patients with high plasma fibrinogen levels, 28 (8.4%) developed postoperative thrombosis (median age: one year, 59% male). In our cohort, 25 (7%) demonstrated evidence of baseline hypercoagulability by one or more panel test results. Thrombosis was associated with greater hospital and blood product costs, longer ventilation times, and longer hospital and ICU length of stays. Preoperative hypercoagulable state (odds ratio: 2.58, 95% CI [1.07, 9.99], p = 0.002), postoperative red blood cell transfusion (odds ratio: 1.007, 95% CI [1.000, 1.015], p = 0.04), and single ventricle physiology (univariate odds ratio: 2.94, 95% CI [1.09, 7.89], p = 0.03) were predictors of postoperative thrombosis. Preoperative hypercoagulable state and intraoperative platelet transfusion were predictors of hospital cost. Thrombosis was associated with worse in-hospital outcomes and higher costs. Preoperative hypercoagulable state and postoperative red blood cell transfusion were significant predictors of thrombosis. Risk prediction models that can guide thrombosis prevention are needed to improve outcomes of patients undergoing congenital heart surgery.

Why partial heart transplantation could be regulated as organ transplantation.

Partial heart transplant (PHT) is a recent clinical innovation involving the transplantation of a segment of the heart (valves) directly from the deceased donor into the recipient patient. This procedure holds out the possibility of significant benefit, especially for pediatric patients because these grafts show growth potential after transplant, reducing or eliminating the current need for repeat procedures. The clinical process for donation and transplant of partial heart (PH) grafts generally follows an organ clinical pathway; however, the Food and Drug Administration has recently stated its intent to regulate PH as tissues, raising a host of regulatory considerations. PHT requires donor testing and eligibility determinations within a short, clinically viable timeframe and, similar to organ transplant, involves donor-recipient matching. Waitlist allocation policies that are a regulatory focus of the Organ Procurement and Transplantation Network including equity and efficiency may become relevant. Oversight of PHT by the Organ Procurement and Transplantation Network could be accomplished through interpretation of the vascular composite allograft definition or through designation by the US Department of Health and Human Services of PH grafts as organs. While some clinical questions remain unanswered, it is important to carefully address these regulatory considerations to support the emergence of this innovation and ensure the continued trust of the donating public and the patients who may benefit from PHT.

Endocardial Fibroelastosis Resection: When it Works and When it Does Not.

Endocardial fibroelastosis (EFE) is a thickening of the endocardial layer by accumulation of collagen and elastic fibers. Endothelial to mesenchymal transformation is proposed to be the underlying mechanism of formation. Although EFE can occur in both right and left ventricles, this article will focus on management of left ventricular EFE. Through its fibrous, nonelastic manifestation EFE restricts the myocardium leading to diastolic and systolic ventricular dysfunction and prevents ventricular growth in neonates and infants. The presence of EFE may be a marker for underlying myocardial fibrosis as well. The extent of EFE within the left ventricular cavity can be variable ranging from patchy to confluent distribution. Similarly the depth of penetration and degree of infiltration into myocardium can be variable. The management of EFE is controversial, although resection of EFE has been reported as part of the staged ventricular recruitment therapy. Following resection, EFE recurs and infiltrates the myocardium after primary resection. Herein we review the current experience with EFE resection.

Cleft closure and other predictors of contemporary outcomes after atrioventricular canal repair in patients with parachute left atrioventricular valve.

OBJECTIVES: Parachute left atrioventricular valve (LAVV) complicates atrioventricular septal defect (AVSD) repair. We evaluate outcomes of AVSD patients with parachute LAVV and identify risk factors for adverse outcomes. METHODS: We evaluated all patients undergoing repair of AVSD with parachute LAVV from 2012 to 2021. The primary outcome was a composite of time-to-death, LAVV reintervention and development of greater than or equal to moderate LAVV dysfunction (greater than or equal to moderate LAVV stenosis and/or LAVV regurgitation). Event-free survival for the composite outcome was estimated using Kaplan-Meier methodology and competing risks analysis. Cox proportional hazards regression was used to identify predictors of the primary outcome. RESULTS: A total of 36 patients were included with a median age at repair of 4 months (interquartile range 2.3-5.5 months). Over a median follow-up of 2.6 years (interquartile range 1.0-5.6 years), 6 (17%) patients underwent LAVV reintervention. All 6 patients who underwent LAVV reintervention had right-dominant AVSD. Sixteen patients (44%) met the composite outcome, and all did so within 2 years of initial repair. Transitional AVSD (versus complete), prior single-ventricle palliation, leaving the cleft completely open and greater than or equal to moderate preoperative LAVV regurgitation were associated with a higher risk of LAVV reintervention in univariate analysis. In multivariate analysis, leaving the cleft completely open was associated with the composite outcome. CONCLUSIONS: Repair of AVSD with parachute LAVV remains a challenge with a significant burden of LAVV reintervention and dysfunction in medium-term follow-up. Unbalanced, right-dominant AVSDs are at higher risk for LAVV reintervention. Leaving the cleft completely open might independently predict poor overall outcomes and should be avoided when possible. CLINICAL TRIAL REGISTRATION NUMBER: IRB-P00041642.

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.

Association of tetralogy of Fallot and complete atrioventricular canal: a single-centre 40-year experience.

OBJECTIVES: Outcome data in tetralogy of Fallot (ToF) and complete atrioventricular canal (CAVC) are limited. We report our experience for over 40 years in this patient population. METHODS: Single-centre, retrospective analysis of patients who underwent surgical repair with the diagnosis of ToF-CAVC from 1979 to 2022, divided into 2 different periods and compared. RESULTS: A total of 116 patients were included: 1979-2007 (n = 61) and 2008-2021 (n = 55). Balanced CAVC (80%) and Rastelli type C CAVC (81%) were most common. Patients in the later era were younger (4 vs 14 months, P < 0.001), fewer had trisomy 21 (60% vs 80%, P = 0.019) and fewer had prior palliative prior procedures (31% vs 43%, P < 0.001). In the earlier era, single-patch technique was more common (62% vs 16%, P < 0.001), and in recent era, double-patch technique was more common (84% vs 33%, P < 0.001). In the earlier era, right ventricular outflow tract was most commonly reconstructed with transannular patch (51%), while in more recent era, valve-sparing repairs were more common (69%) (P < 0.001). In-hospital mortality was 4.3%. The median follow-up was 217 and 74 months for the first and second eras. Survival for earlier and later eras at 2-, 5- and 10-year follow-up was (85.1%, 81.5%, 79.6% vs 94.2%, 94.2%, 94.2% respectively, log-rank test P = 0.03). CONCLUSIONS: The surgical approach to ToF-CAVC has evolved over time. More recently, patients tended to receive primary repair at younger ages and had fewer palliative procedures. Improved surgical techniques allowing for earlier and complete repair have shown a decrease in mortality, more valve-sparing procedures without an increase in total reoperations. Presented at the 37th EACTS Annual Meeting, Vienna, Austria.