Long-Term Outcomes Following the Ross Procedure in Neonates and Infants: A Multi-Institutional Analysis.

OBJECTIVES: For neonates and infants with aortic valve pathology, the Ross procedure has historically been associated with high rates of morbidity and mortality. Data regarding long-term durability are lacking. METHODS: The international, multi-institutional Ross Collaborative included six tertiary-care centers. Infants who received a Ross operation between 1996-2016 (allowing a minimum five years of follow-up) were retrospectively identified. Serial echocardiograms were examined to study evolution in neoaortic size and function. RESULTS: Primary diagnoses for the 133 patients (n=30 neonates) included isolated aortic stenosis (AS; 14%, n=19), Shone complex (14%, n=19), and AS+other (excluding Shone complex; n=95, 71%) including arch obstruction (n=55), left ventricular hypoplasia (n=9), and mitral disease (>moderate stenosis or regurgitation, n=31). At the time of Ross, median age was 96 (IQR 36-186) days and median weight was 4.4 (3.6-6.5) kg. In-hospital mortality occurred in 13/133 (10%) patients (4/30 [13%] neonates). Post-discharge mortality occurred in 10/120 (8%) patients at a median 298 days post-Ross. Post-Ross neoaortic dilatation occurred, peaking at 4-5 standard deviations above normal at 2-3 years before returning to near-baseline z-score at a median follow-up of 11.5 [6.4-17.4] years. Autograft/LVOT reintervention was required in 5/120 (4%) patients at a median 10.3 [4.1-12.8] years. Freedom from >moderate neoaortic regurgitation (AR) was 86% at 15 years. CONCLUSIONS: Neonates and infants experience excellent post-discharge survival and long-term freedom from autograft reintervention and AR following Ross. Neoaortic dilatation normalizes in this population in the long-term. Increased consideration should be given to Ross in neonates and infants with aortic valve disease.

Development of a novel 3D perfusable vascular graft model to elucidate the mechanisms for congenital heart disorders.

Pediatric heart transplantation is hampered by a chronic shortage of donor organs. This problem is further confounded by graft rejection. Identification of earlier indicators of pediatric graft rejection and development of subsequent strategies to counteract these effects will increase the longevity of transplanted pediatric hearts. Heart transplant reject is due to a complex series of events, resulting in CAV, which is thought to be mediated through a host immune response. However, the earlier events leading to CAV are not very well known. We hypothesize that early events related to ischemia reperfusion injury during pediatric heart transplantation are responsible for CAV and subsequent graft rejection. Identification of the molecular markers of ischemia reperfusion injury and development of subsequent therapies to block these pathways can potentially lead to a therapeutic strategy to reduce CAV and increase the longevity of the transplanted heart. To accomplish this goal, we have developed a perfusable vascular graft model populated with endothelial cells and demonstrated the feasibility of this model to understand the early events of ischemia reperfusion injury.

Long-Term Outcomes of Ascending Sliding Arch Aortoplasty.

Background: Coarctation of the aorta can be associated with significant hypoplasia of the aortic arch. In contrast to patch aortoplasty, ascending sliding arch aortoplasty uses viable autologous tissue for potential growth in children. We reviewed the mid- to long-term outcomes of this technique. Methods: Between 2002 and 2023, 28 patients underwent ascending sliding arch aortoplasty for the patients with coarctation of the aorta (n = 22) and interrupted aortic arch (n = 2). Four patients underwent previous surgical coarctation repair at other institutions. The median patient age and body weight were 28.5 months (3 weeks to 15.6 years) and 13.4 kg (3.7-70 kg), respectively. Results: Although one patient had a recurrent nerve injury postoperatively, there were no other major morbidities or mortalities. The last follow-up echocardiography demonstrated that the mean peak velocity improved from 3.9 ± 0.6 to 0.9 ± 0.8 m/s, and the pressure gradient improved from 63.6 ± 21.5 to 7.1 ± 7.7 mm Hg. The postoperative diameters of the ascending aorta, proximal arch, distal arch, and isthmus all increased significantly. The mean postoperative length of stay was 5.9 ± 2.1 days, and the median follow-up time was 7.3 years (10 days to 20.5 years). No reoperation or catheterization-based intervention was performed for residual coarctation. Conclusions: Ascending sliding arch aortoplasty is safe and effective for treating coarctation of the aorta with aortic arch hypoplasia. This technique is applicable for children ranging in size from neonates to older children (or adolescents), recurrent coarctation cases, and provides complete relief of narrowing by utilizing viable native aortic tissue.

Long-term implantable ventricular assist device support in children.

BACKGROUND: In pediatrics, implantable continuous-flow ventricular assist devices (IC-VAD) are often used as a "temporary" support, bridging children to cardiac transplantation during the same hospital admission. METHODS: We conducted a retrospective review of our consecutive patients undergoing IC-VAD support at a tertiary pediatric heart center between 2008 and 2022. RESULTS: We identified 100 IC-VAD implant encounters: HeartWare HVAD (67; 67%), HeartMate II (17; 17%), and HeartMate 3 (16; 16%). The median (range) age, weight, and body surface area at implantation were 14.1 (3.0-56.5) years, 54.8 (13.3-140) kg, and 1.6 (0.6-2.6) m2, respectively. Cardiomyopathy (58; 58%) was the most common etiology, followed by congenital heart disease (37; 37%, including 13 single ventricle). At 6 months of IC-VAD support, 94 (94%) encounters achieved positive outcomes: ongoing support (59; 59%), transplant (33; 33%), and cardiac recovery (2; 2%). Eighty-two encounters (82%) resulted in home discharge with ongoing VAD support, including 38 (46%, out of 82) requiring readmission and 7 (9%, out of 82) resulting in death. There was a clinically significant decrease in morbidity rates before versus after home discharge: bleeding (1.55 vs 0.06), infection (0.84 vs 0.37), and stroke (0.84 vs 0.15 event per patient-year). Overall, 86 encounters (86%) reached positive end points at the latest follow-up (64 transplant, 15 ongoing support, and 7 recovery). Infection (29%; 4 of 14) was the most common cause of negative outcomes, followed by cerebrovascular accident (21%; 3), and unresolved frailty (21%; 3). The estimated overall survival at 1, 2, and 5 years was 90%, 86%, and 77%, respectively. CONCLUSIONS: This study suggests the feasibility of outpatient management of pediatric IC-VAD support. The ability to offer true long-term support maximizes the potential of IC-VAD support, not limited to a temporary bridging tool for heart transplantation.

Anterior Chest Wall Reconstruction After Separation of Thoraco-Omphalopagus Conjoined Twins With Cadaveric Rib Grafts and Omental Flap.

BACKGROUND: Anterior chest wall defects have a wide range of etiologies in the pediatric population, ranging from infection, tumor, and trauma to congenital diseases. The reconstructive goals include restoring skeletal stability, obliterating dead space, preserving cardiopulmonary mechanics, and protecting vital underlying mediastinal organs. Although various reconstructive methods have been described in the literature, selecting the optimal method is challenging for the growing pediatric skeleton. Here, we report a case of previously thoraco-omphalopagus twins who underwent successful separation and reconstruction and presented for definitive anterior chest wall reconstruction. METHODS: A pair of previously thoraco-omphalopagus conjoined twins underwent definitive anterior chest wall defect reconstruction using cadaveric ribs and omental flap. Twin A received 2 cadaveric ribs, whereas twin B had a much larger sternal defect that required 3 cadaveric ribs combined with an omental flap for soft tissue chest coverage. Both twins were followed up for 8 months. RESULTS: Twin A's postoperative course was uneventful, and she was discharged on postoperative day 6. Twin B's course was complicated, and she was discharged on supported ventilation on postoperative day 10. At 8 months postoperatively, both twins healed well, and chest radiographs confirmed the stability of the chest reconstructions. The rib grafts in the twin with a tracheostomy were not mobile, and the patient had a solid sternum with adequate pulmonary expansion. The construct initially did not facilitate pulmonary functioning, but after a healing process, it eventually allowed for the twin with the tracheostomy who required pulmonary assistance to no longer need this device. CONCLUSIONS: Cryopreserved cadaveric ribs and omental flaps offer safe and reliable reconstructive methods to successfully reconstruct congenital anterior chest wall skeletal defects in the growing pediatric population. The involvement of multidisciplinary team care is key to optimizing the outcomes.

Comparing palliation strategies for single-ventricle anatomy with transposed great arteries and systemic outflow obstruction.

Objective: Patients with complex single-ventricle anatomy with transposed great arteries and systemic outflow obstruction (SV-TGA-SOO) undergo varied initial palliation with ultimate goal of Fontan circulation. We examine a longitudinal experience with multiple techniques, including the largest published cohort following palliative arterial switch operation (pASO), to describe outcomes and decision-making factors. Methods: Neonates with SV-TGA-SOO who underwent initial surgical palliation from 1995 to 2022 at a single institution were retrospectively reviewed. Results: In total, 71 neonates with SV-TGA-SOO underwent index surgical palliation at a median age of 7 days (interquartile range, 6-10) by pASO (n = 23), pulmonary artery band (PAB) with or without arch repair (n = 25), or modified Norwood with Damus-Kaye-Stansel aortopulmonary amalgamation (n = 23). Single-ventricle pathology included double-inlet left ventricle (n = 37, 52%), tricuspid atresia (n = 27, 38%), and others (n = 7, 10%). All mortalities (n = 5, 7%) occurred in the first interstage period after PAB (n = 3) and Norwood (n = 2). Subaortic obstruction in the PAB group was addressed by operative resection (n = 10 total, 7 at index operation) and/or delayed aortopulmonary amalgamation (n = 13, 52%). Two patients with pASO (9%) had early postoperative coronary complications, 1 requiring operative revision. Median follow-up for survivors was 10.4 years (interquartile range, 4.5-16.6 years). Comparing patients by their initial palliation type, notable significant differences included size of bulboventricular foramen, weight at initial operation, operation duration, postoperative length of stay, time to second-stage palliation, multiple pulmonary artery reinterventions, and left pulmonary artery interventions. There were no significant differences in overall survival, Fontan completion, reintervention-free survival in the first interstage period, pulmonary artery reintervention-free survival, long-term systemic valve competency, or ventricular dysfunction. Conclusions: Excellent mid- to long-term outcomes are achievable following neonatal palliation for SV-TGA-SOO via pASO, PAB, and modified Norwood, with comparable survival and Fontan completion. Initial palliation strategy should be individualized to optimize anatomy and physiology for successful Fontan by ensuring an unobstructed subaortic pathway and accessible pulmonary arteries. pASO is a reasonable strategy to consider for these heterogeneous lesions.

Clinical Presentation and Medium-Term Outcomes of Children With Anomalous Aortic Origin of the Left Coronary Artery: High-Risk Features Beyond Interarterial Course.

BACKGROUND: Anomalous aortic origin of the left coronary artery (AAOLCA) confers a rare, but significant, risk of sudden cardiac death in children. Surgery is recommended for interarterial AAOLCA, and other subtypes considered benign. We aimed to determine the clinical characteristics and outcomes of 3 AAOLCA subtypes. METHODS: All patients with AAOLCA <21 years old were prospectively enrolled (December 2012-November 2020), including group 1: AAOLCA from the right aortic sinus with interarterial course, group 2: AAOLCA from the right aortic sinus with intraseptal course, and group 3: AAOLCA with a juxtacommissural origin between the left and noncoronary aortic sinus. Anatomic details were assessed using computed tomography angiography. Provocative stress testing (exercise stress testing and stress perfusion imaging) was performed in patients >8 years old or younger if concerning symptoms. Surgery was recommended for group 1 and in select cases in group 2 and group 3. RESULTS: We enrolled 56 patients (64% males) with AAOLCA (group 1, 27; group 2, 20; group 3, 9) at median age of 12 years (interquartile range, 6-15). Intramural course was common in group 1 (93%) compared with group 3 (56%) and group 2 (10%). Seven (13%) presented with aborted sudden cardiac death (group 1, 6/27; group 3, 1/9); 1 (group 3) with cardiogenic shock. Fourteen/42 (33%) had inducible ischemia on provocative testing (group 1, 32%; group 2, 38%; group 3, 29%). Surgery was recommended in 31/56 (56%) patients (group 1, 93%; group 2, 10%; and group 3, 44%). Surgery was performed in 25 patients at a median age 12 (interquartile range, 7-15) years; all have been asymptomatic and free from exercise restrictions at median follow-up of 4 (interquartile range, 1.4-6.3) years. CONCLUSIONS: Inducible ischemia was noted in all 3 AAOLCA subtypes while most aborted sudden cardiac deaths occurred in interarterial AAOLCA (group 1). Aborted sudden cardiac death and cardiogenic shock may occur in AAOLCA with left/nonjuxtacommissural origin and intramural course, thus also deemed high-risk. A systematic approach is essential to adequately risk stratify this population.

Ischemia in Anomalous Aortic Origin of a Right Coronary Artery: Large Pediatric Cohort Medium-Term Outcomes.

BACKGROUND: Anomalous aortic origin of a right coronary artery may cause myocardial ischemia and sudden death in the young. Data on myocardial ischemia or longitudinal outcomes are sparse in pediatric anomalous aortic origin of a right coronary artery population. METHODS: Patients <21 years with anomalous aortic origin of a right coronary artery were prospectively enrolled. Computerized tomography angiography defined morphology. Exercise stress test and stress perfusion imaging (sPI) were performed if >7 years or younger with concern for ischemia. High-risk features included intramural length, slit-like/hypoplastic ostium, exertional symptoms, or evidence of ischemia. RESULTS: A total of 220 patients (60% males) were enrolled December 2012 to April 2020 at a median age 11.4 years (interquartile range, 6.1-14.5), including 168 (76%) with no/nonexertional symptoms (group 1) and 52 (24%) with exertional chest pain/syncope (group 2). Computerized tomography angiography was available in 189/220 (86%), exercise stress test in 164/220 (75%), and sPI in 169/220 (77%). Exercise stress test was positive in 2/164 (1.2%) patients in group 1, both had positive sPI. Inducible ischemia (sPI) was detected in 11/120 (9%) in group 1 and 9/49 (18%) in group 2 (P=0.09). Intramural length was similar in patients with/without ischemia (5 [interquartile range, 4-7] versus 5 [interquartile range, 4-7] mm; P=0.65). Surgery was recommended in 56/220 (26%) patients with high-risk features. In 52 surgical patients (38 unroofing, 14 reimplantation), all subjects were alive and have returned to exercise at last median follow-up of 4.6 (interquartile range, 2.3-6.5) years. CONCLUSIONS: Anomalous aortic origin of a right coronary artery patients can present with inducible ischemia on sPI despite symptoms or intramural length. Exercise stress test is a poor predictor of ischemia and caution should be given to determine low-risk based solely on this assessment. All patients are alive at medium-term follow-up.

Use of Berlin EXCOR cannulas in both venovenous and venoarterial central extracorporeal membrane oxygenation configurations overcomes the problem of cannula instability while bridging infants and young children to lung transplant.

Objectives: Infants and young children awaiting lung transplantation present challenges that often preclude successful extracorporeal membrane oxygenation support as a bridge to transplantation. Instability of neck cannulas often results in the need for intubation, mechanical ventilation, and muscle relaxation creating a worse transplant candidate. With the use of Berlin Heart EXCOR cannulas (Berlin Heart, Inc) in both venoarterial and venovenous central cannulation configurations, 5 pediatric patients were successfully bridged to lung transplant. Methods: We performed a single-center retrospective case review of central extracorporeal membrane oxygenation cannulation used as a bridge to lung transplantation cases performed at Texas Children's Hospital between 2019 and 2021. Results: Six patients, 2 with pulmonary veno-occlusive disease (15-month-old male and 8-month-old male), 1 with ABCA3 mutation (2-month-old female), 1 with surfactant protein B deficiency (2-month-old female), 1 with pulmonary arterial hypertension in the setting of D-transposition of the great arteries after repair as a neonate (13-year-old male), and 1 with cystic fibrosis and end-stage lung disease, were supported for a median of 56.3 days on extracorporeal membrane oxygenation while awaiting transplantation. All patients were extubated after initiation of extracorporeal membrane oxygenation, participating in rehabilitation until transplant. No complications due to central cannulation and use of the Berlin Heart EXCOR cannulas were observed. One patient with cystic fibrosis developed fungal mediastinitis and osteomyelitis resulting in discontinuation of mechanical support and death. Conclusions: Novel use of Berlin Heart EXCOR cannulas for central cannulation eliminates the problem of cannula instability allowing extubation, rehabilitation, and bridge to lung transplant for infants and young children.

Evolution of surgical repair of intraseptal anomalous left coronary artery with myocardial ischaemia.

BACKGROUND: Anomalous aortic origin of the left coronary artery with intraseptal course is a rare coronary anomaly associated with an increased risk of myocardial ischaemia. The role and techniques for surgical intervention are evolving, with numerous novel surgical techniques for this challenging anatomy reported in the last 5 years. We report our single-centre experience with surgical repair of intraseptal anomalous left coronary artery in the paediatric population, including clinical presentation, evaluation, and short- to mid-term outcomes. METHODS: All patients with coronary anomalies presenting to our institution undergo standardised clinical evaluation. Five patients aged 4 to 17 years underwent surgical intervention for intraseptal anomalous aortic origin of the left coronary artery between 2012 and 2022. Surgical techniques included coronary artery bypass grafting (n = 1), direct reimplantation with limited supra-arterial myotomy via right ventriculotomy (n = 1), and transconal supra-arterial myotomy with right ventricular outflow tract patch reconstruction (n = 3). RESULTS: All patients had evidence of haemodynamically significant coronary compression, and three had evidence of inducible myocardial ischaemia pre-operatively. There were no deaths or major complications. Median follow-up was 6.1 months (range 3.1-33.4 months). Patients who underwent supra-arterial myotomy (with or without reimplantation) had improved coronary flow and perfusion based on stress imaging and catheterisation data. CONCLUSIONS: Surgical approaches to intraseptal anomalous left coronary artery with evidence of myocardial ischaemia continue to evolve, with new techniques demonstrating promising improvement in coronary perfusion. Further studies are warranted to determine long-term outcomes and refine indications for repair.

Intramural course of an anomalous left coronary artery is not always associated with a slit-like ostium.

Anomalous aortic origin of the left coronary artery from an incorrect aortic sinus has been reported as the second most common causes of sudden cardiac arrest in young athletes. Intramural course of the proximal left coronary artery is considered a high-risk morphology. It is associated with a slit-like ostium and elliptical shape of the proximal artery. In this case, all pre-operative cardiac images demonstrated a round ostium and round luminal shape of the left coronary artery, which suggested no evidence of intramural course. On intraoperative inspection, although the ostium and proximal left coronary artery appeared round, the patient had a long intramural course of the left coronary artery which our surgeons performed a successful unroofing procedure. The post-operative images showed a patent new ostium from the correct aortic sinus. These findings are very unusual and proved that we should not exclude intramural course even in the absence of a slit-like ostium and elliptical shape of the proximal left coronary artery.

Cumulative comorbid conditions influence mortality risk after staged palliation for hypoplastic left heart syndrome and variants.

OBJECTIVE: Prematurity, low birth weight, genetic syndromes, extracardiac conditions, and secondary cardiac lesions are considered high-risk conditions associated with mortality after stage 1 palliation. We report the impact of these conditions on outcomes from a prospective multicenter improvement collaborative. METHODS: The National Pediatric Cardiology Quality Improvement Collaborative Phase II registry was queried. Comorbid conditions were categorized and quantified to determine the cumulative burden of high-risk diagnoses on survival to the first birthday. Logistic regression was applied to evaluate factors associated with mortality. RESULTS: Of the 1421 participants, 40% (575) had at least 1 high-risk condition. The aggregate high-risk group had lower survival to the first birthday compared with standard risk (76.2% vs 88.1%, P < .001). Presence of a single high-risk diagnosis was not associated with reduced survival to the first birthday (odds ratio, 0.71; confidence interval, 0.49-1.02, P = .066). Incremental increases in high-risk diagnoses were associated with reduced survival to first birthday (odds ratio, 0.23; confidence interval, 0.15-0.36, P < .001) for 2 and 0.17 (confidence interval, 0.10-0.30, P < .001) for 3 to 5 high-risk diagnoses. Additional analysis that included prestage 1 palliation characteristics and stage 1 palliation perioperative variables identified multiple high-risk diagnoses, poststage 1 palliation extracorporeal membrane oxygenation support (odds ratio, 0.14; confidence interval, 0.10-0.22, P < .001), and cardiac reoperation (odds ratio, 0.66; confidence interval, 0.45-0.98, P = .037) to be associated with reduced survival odds to the first birthday. CONCLUSIONS: The presence of 1 high-risk diagnostic category was not associated with decreased survival at 1 year. Cumulative diagnoses across multiple high-risk diagnostic categories were associated with decreased odds of survival. Further patient accrual is needed to evaluate the impact of specific comorbid conditions within the broader high-risk categories.

Differential donor management of pediatric vs adult organ donors and potential impact on pediatric lung transplantation.

BACKGROUND: Despite clinical progress over time, a shortage of suitable donor organs continues to limit solid organ transplantation around the world. Lungs are the organs most likely to be assessed as unsuitable during donor management among all transplantable organs. Although the number of lung transplants performed in children is limited, death on the wait list remains a barrier to transplant success for many potential transplant candidates. Optimizing organ donor management can yield additional organs for transplant candidates. METHODOLOGY: We accessed the Donor Management Goal (DMG) Registry to evaluate the efficiency and efficacy of donor management in the procurement of lungs for transplantation. Further, we stratified donors by age and compared pediatric age cohorts to adult cohorts with respect to attainment of donor management target goals and successful pathway to transplantation. We utilized recipient data from the Organ Procurement Transplantation Network (OPTN) to put this data into context. The DMG bundle consists of nine physiologic parameters chosen as end-points guiding donor management for potential organ donors. The number of parameters fulfilled has been regarded as an indication of efficacy of donor management. RESULTS: We noted a markedly lower number of organ donors in the pediatric age group compared to adults. On the other hand, the number of donors greatly exceeds the number of infants, children and adolescents who undergo lung transplantation. Organs transplanted per donor peaks in the adolescent age group. At initial donor referral, DMG bundle attainment is lower in all age groups and improves during donor management. With respect to oxygenation, there is less overall improvement in younger donors compared to older donors during donor management. When donors who yield lungs for transplantation are compared to those whose lungs were not transplanted, oxygenation improved more substantially during donor management. Furthermore, improved oxygenation correlated with the total number of organs transplanted per donor. CONCLUSIONS: In the face of continued wait list mortality on the pediatric lung transplant wait list, the number of young donors may not be a limiting factor. We believe that this dataset provides evidence that management of young pediatric donors is not as consistent or efficient as the management of older donors, potentially limiting the number of life-saving organs for pediatric lung transplant candidates. Across all ages, optimizing donor lung management may increase the potential to transplant multiple other organs.

Outcomes of temporary ventricular assist device: A pediatric institutional experience over 25 years.

BACKGROUND: There are scarce data describing outcomes of pediatric temporary ventricular assist device support. METHODS: A retrospective single-center study was conducted to review clinical outcomes of all consecutive patients with temporary ventricular assist device between 1996 and 2021. Given the complex clinical course in some patients requiring multiple temporary ventricular assist device runs, outcome analysis was based on "encounters" (hospitalizations with temporary ventricular assist device, regardless of the number of devices used). RESULTS: In total, 126 temporary ventricular assist devices were implanted in 108 patients, resulting in a total of 114 encounters: 70 (61%) extracorporeal centrifugal pumps and 44 (39%) catheter-based axial pumps. The median (range) age and weight at temporary ventricular assist device implant were 10.1 years (1 day to 42.8 years) and 33.6 (2.5-128) kg, respectively. Underlying etiologies of cardiac dysfunction were cardiomyopathy (34, 30%), cardiac transplant graft dysfunction (29, 25%), congenital heart disease (23, 20%; 9 single ventricle), myocarditis (22, 19%), and other (6, 5%). Interagency Registry for Mechanically Assisted Circulatory Support Profile was 1 in 75 (66%) and 2 in 39 (34%). Support configuration was left ventricular assist device (104, including 9 systemic ventricular assist devices), right ventricular assist device (5), and biventricular assist device (5). The median (range) support duration was 6 (1-61) days. Overall, 97 (85%) encounters reached a positive primary end point: bridge-to-recovery (55), bridge-to-bridge (31), and bridge-to-transplant directly with temporary ventricular assist device (11). Seventeen (15%) encounters resulted in death during temporary ventricular assist device support: multiorgan failure (12), stroke (4), and cardiac arrest (1). The 6-month survivals with catheter-based axial pumps and extracorporeal centrifugal pumps were 84% (95% confidence interval, 74-96) and 67% (95% confidence interval, 57-79), respectively (P = .08). The 1- and 5-year survivals of 82 hospital survivors were 90% and 84%, respectively. CONCLUSIONS: This study suggests temporary ventricular assist device support is feasible in children with favorable outcomes.

Improved Outcomes for Infants and Young Children Undergoing Lung Transplantation at Three Years of Age and Younger.

Rationale: Since its inception, older children and adolescents have predominated in pediatric lung transplantation. Most pediatric lung transplant programs around the world have transplanted few infants and young children. Early mortality after lung transplantation and inadequate donor organs have been perceived as limitations for success in lung transplantation at this age. Objectives: Our aim was to describe our experience in a large pediatric lung transplant program with respect to lung transplantation in infants and young children, focusing on diagnosis, waitlist, and mortality. Methods: We performed a retrospective review of infants and young children under 3 years of age at the time of transplant in our program from 2002 through 2020. Results: The patient cohort represented a severely morbid recipient group, with the majority hospitalized in the intensive care unit on mechanical ventilation just before transplantation. There was a marked heterogeneity of diagnoses distinct from diagnoses in an older cohort. Waitlist time was shorter than in older age cohorts. There was a decrease in early mortality, lower incidence of allograft rejection, and satisfactory long-term survival in this age group compared with the older cohort and published experience. Severe viral infection was an important cause of early mortality after transplant. Nonetheless, survival is comparable to older patients, with better enduring survival in those who survive the early transplant period in more recent years. Conclusions: Carefully selected infants and young children with end-stage lung and pulmonary vascular disease are appropriate candidates for lung transplantation and are likely underserved by current clinical practice.

Decellularized vs Non-decellularized Allogeneic Pulmonary Artery Patches for Pulmonary Arterioplasty.

We studied pulmonary artery size, reinterventions, and panel reactive antibodies in patients with single-ventricle physiology who underwent a pulmonary arterioplasty with decellularized (DAPAP) and non-decellularized allogeneic pulmonary artery patches (non-DAPAP). Retrospective review identified 59 patients with single-ventricle physiology who underwent pulmonary arterioplasty from 2008 to 2017: 28 patients underwent arterioplasty with DAPAP and 31 patients with non-DAPAP. Demographic and operative variables were similar between groups. Among patients who underwent a Norwood procedure, a right ventricle to pulmonary artery shunt was more commonly used in the DAPAP group (12/20, 60%) and a modified Blalock-Taussig shunt was more commonly used in the non-DAPAP group (17/22, 77%). On multivariable analysis, the use of DAPAP was associated with higher pre-Fontan angiography Z-scores in right (estimate = 0.17, standard error = 0.04, P = 0.0005) and left pulmonary arteries (estimate = 0.12, standard error = 0.05, P = 0.01). No areas of calcification, discrete coarctation, or pulmonary dilation were noted in any of the pulmonary arteries. On multivariable analysis, the use of DAPAP was associated with higher freedom from pulmonary artery reinterventions (Hazard ratio = 0.36, 95% confidence interval = 0.13-0.9, P = 0.04). The median value for Class I panel reactive antibodies was 0% (IQR 0, 4) in the DAPAP and 23% (IQR 14, 36) in the non-DAPAP group. The median value for Class II panel reactive antibodies was 15% (IQR 0, 17) in the DAPAP and 21% (IQR 10, 22) in the non-DAPAP group. Pulmonary arterioplasty with DAPAP was associated with higher pre-Fontan pulmonary artery Z-scores and higher freedom from pulmonary artery reinterventions.

Atrial tachyarrhythmias after lung transplantation in children: A common occurrence.

BACKGROUND: Atrial arrhythmia's (AA) following lung transplant in adults are a well-described clinical finding. In pediatrics, however, there are limited data with some reports suggesting that arrhythmias are rare. METHODS: We performed a single-center retrospective review of lung transplant recipients from January 2013 to June 2020. A detailed evaluation of clinical characteristics, presence of arrhythmias, and outcomes was completed. Arrhythmias were documented based on inpatient telemetry or remote Holter monitoring. Analyses assessing risk factors for arrhythmias and associations with clinical outcomes were performed. RESULTS: Ninety-one lung transplants were performed in 90 patients. Post-operative AA occurred following 19% transplants. Ectopic atrial tachycardia was seen in 14%, atrial flutter in 2%, and a combination in 2%. The majority of these arrhythmias occurred within the first 45 days post-operatively. Antiarrhythmic treatment was required in 59%, but none required ablation or electrical cardioversion. In patients followed for a year or more, 88% had resolution of their arrhythmia. Arrhythmias were not associated with mortality. In further analysis, however, the presence of arrhythmia was associated with an increased length of ICU stay (median of 12 days (IQR 6, 23) versus 5 days (IQR 4, 9); p = .019) and overall length of hospital stay (median of 26 days (IQR 19, 36) versus 17 days (IQR 19, 36); p = .043). CONCLUSIONS: Atrial tachyarrhythmias after lung transplantation are common in the pediatric population and usually occur early. Although they frequently require medical therapy and are associated with longer stays, there is no associated increased mortality. In addition, the arrhythmias typically self-resolve.

The acute influence of vasopressin on hemodynamic status and tissue oxygenation following the Norwood procedure.

Objectives: Arginine vasopressin (AVP) is used to treat hypotension. Because AVP increases blood pressure by increasing systemic vascular resistance, it may have an adverse effect on tissue oxygenation following the Norwood procedure. Methods: Retrospective analysis of continuously captured hemodynamic data of neonates receiving AVP following the Norwood procedure. Results: We studied 64 neonates exposed to AVP within 7 days after the Norwood procedure. For the entire group, AVP significantly increased mean blood pressure (2.5 ± 6.3) and cerebral and renal oxygen extraction ratios (4.1% ± 9.6% and 2.0% ± 4.7%, respectively; P < .001 for all values). In the right ventricle to pulmonary artery shunt cohort, AVP significantly increased blood pressure, arterial oxygen saturation (1.4% ± 3.8%; P = .011), pulmonary to systemic perfusion ratio (0.2 ± 0.4; P = .017), and cerebral and renal oxygen extraction ratios (4.6% ± 8.7%; P = .010% and 4.7% ± 9.4%; P = .014, respectively). The Blalock-Taussig shunt cohort experienced a less significant vasopressor response and no change in arterial oxygen saturation, pulmonary to systemic perfusion ratio, or cerebral and renal oxygen extraction ratios. Conclusions: The right ventricle to pulmonary artery shunt cohort experienced a significant vasopressor response to AVP that was associated with a significant increase in pulmonary perfusion and decrease in cerebral and renal perfusion, whereas the Blalock-Taussig shunt cohort experienced a less significant vasopressor response and no change in pulmonary or systemic perfusion. The influence of AVP on tissue oxygenation following the Norwood procedure may have clinical implications that require further study.

Left heart hypoplasia in the fetus: Echocardiographic predictors of outcome.

INTRODUCTION: Fetal left heart hypoplasia (LHH) with an apex-forming left ventricle may require neonatal intervention but it is difficult to predict. METHODS: We performed a retrospective study of fetuses with LHH defined as normal segmental anatomy, apex-/near-apex forming left ventricle, and ≥1 left-sided z-score ≤ -2 between 1997 and 2014. Fetuses with mitral or aortic atresia, critical aortic stenosis, extracardiac anomalies, or fetal intervention were excluded. Classification and regression tree analyses (CART) were performed to construct algorithms to predict postnatal circulation: no surgery versus biventricular surgery versus single ventricle (SV) palliation. RESULTS: Among 138 included fetuses, 52 (37%) underwent neonatal surgery, with 10 (7%) undergoing SV palliation. The strongest single outcome discriminator was exclusively left-to-right flow foramen ovale (FO) flow ≥32 weeks gestational age (GA) (seen in 0% with no surgery, 22% with biventricular surgery, 88% with SV palliation). On CART analysis >32 weeks GA, fetuses with right-to-left FO flow and aortopulmonary ratio >0.76 had 0% probability of neonatal surgery, while those with left-to-right FO flow and mitral valve z-score < -3.6 had a 70% probability of SV palliation. CONCLUSION: SV palliation is an uncommon outcome of fetal LHH. Fetal FO flow and other echocardiographic measures can help determine risk and type of postnatal intervention.

Opioid Weaning Protocol Using Morphine Compared With Nonprotocolized Methadone Associated With Decreased Dose and Duration of Opioid After Norwood Procedure.

OBJECTIVES: Opioids are used to manage pain, comfort, maintain devices, and decrease oxygen consumption around Norwood palliation (NP), but in high dose and prolonged exposure, they increase risk of tolerance and iatrogenic withdrawal syndrome (IAWS). Variability in practice for IAWS prevention potentially increases opioid dose and duration. We hypothesize that protocolized weaning with morphine (MOR) versus nonprotocolized methadone (MTD) is associated with reduction in opioid exposure. DESIGN: A before-versus-after study of outcomes of patients weaned with protocolized MOR versus nonprotocolized MTD including subset analysis for those patients with complications postoperatively. Primary endpoints include daily, wean phase, and total morphine milligram equivalent (MMEq) dose, duration, and, secondarily, length of stay (LOS). SETTING: Quaternary-care pediatric cardiac ICU. PATIENTS: Neonates undergoing single-ventricle palliation. INTERVENTIONS: Introduction of IAWS prevention protocol. MEASUREMENTS AND MAIN RESULTS: Analysis included 54 patients who underwent the NP in 2017-2018 including the subset analysis of 34 who had a complicated postoperative course. The total and wean phase opioid doses for the MTD group were significantly higher than that for the MOR group: 258 versus 22 and 115 versus 6 MMEq/kg; p < 0.001. Duration of opioid exposure was 63 days in the MTD group and 12 days in MOR group (p < 0.001). Subanalysis of the complicated subset also identifies higher total and wean dose for MTD group (293 vs 41 and 116 vs 7 MMEq/kg; p < 0.001) with a longer duration (65 vs 22 days; p = 0.001). Within the subset, LOS was 55% longer in the MTD group than that in the MOR group (150 vs 67 d; p = 0.01) and not different in the uncomplicated group. CONCLUSIONS: After complex NP, a protocolized opioid weaning using MOR versus MTD is associated with 65% shorter opioid duration, 10-fold decreased dose, and shortened LOS.