Echocardiographic assessment of cardiovascular physiology of preterm miniature piglets supported with a pumped artificial placenta system.

OBJECTIVES: We evaluated fetal cardiovascular physiology and mode of cardiac failure in premature miniature piglets on a pumped artificial placenta (AP) circuit. METHODS: Fetal pigs were cannulated via the umbilical vessels and transitioned to an AP circuit composed of a centrifugal pump and neonatal oxygenator and maintained in a fluid-filled biobag. Echocardiographic studies were conducted to measure ventricular function, umbilical blood flow, and fluid status. In utero scans were used as control data. RESULTS: AP fetuses (n = 13; 102±4d gestational age [term 115d]; 616 ± 139 g [g]; survival 46.4 ± 46.8 h) were tachycardic and hypertensive with initially supraphysiologic circuit flows. Increased myocardial wall thickness was observed. Signs of fetal hydrops were present in all piglets. Global longitudinal strain (GLS) measurements increased in the left ventricle (LV) after transition to the circuit. Right ventricle (RV) and LV strain rate decreased early during AP support compared with in utero measurements but recovered toward the end of the experiment. Fetuses supported for >24 h had similar RV GLS to in utero controls and significantly higher GLS compared to piglets surviving only up to 24 h. CONCLUSIONS: Fetuses on a pump-supported AP circuit experienced an increase in afterload, and redistribution of blood flow between the AP and systemic circulations, associated with elevated end-diastolic filling pressures. This resulted in heart failure and hydrops. These preterm fetuses were unable to tolerate the hemodynamic changes associated with connection to the current AP circuit. To better mimic the physiology of the native placenta and preserve normal fetal cardiovascular physiology, further optimization of the circuit will be required.

Impact of cardiopulmonary bypass on cerebrovascular autoregulation assessed by ultrafast ultrasound imaging.

Newborns with congenital heart disease undergoing cardiac surgery are at risk of neurodevelopmental impairment with limited understanding of the impact of intra-operative cardiopulmonary bypass (CPB), deep hypothermia and selective cerebral perfusion on the brain. We hypothesized that a novel ultrasound technique, ultrafast power Doppler (UPD), can assess variations of cerebral blood volume (CBV) in neonates undergoing cardiac surgery requiring CPB. UPD was performed before, during and after surgery in newborns with hypoplastic left heart syndrome undergoing a Norwood operation. We found that global CBV was not significantly different between patients and controls (P = 0.98) and between pre- and post-surgery (P = 0.62). UPD was able to monitor changes in CBV throughout surgery, revealing regional differences in CBV during hypothermia during which CBV correlated with CPB flow rate (R2  = 0.52, P = 0.021). Brain injury on post-operative magnetic resonance imaging was observed in patients with higher maximum variation in CBV. Our findings suggest that UPD can quantify global and regional brain perfusion variation during neonatal cardiac surgery with this first intra-operative application demonstrating an association between CBV and CPB flow rate, suggesting loss of autoregulation. Therefore, the measurement of CBV by UPD could enable optimization of cerebral perfusion during cardiac surgery in neonates. KEY POINTS: The impact of cardiopulmonary bypass (CPB) on the neonatal brain undergoing cardiac surgery is poorly understood. Ultrafast power Doppler (UPD) quantifies cerebral blood volume (CBV), a surrogate of brain perfusion. CBV varies throughout CPB surgery and is associated with variation of the bypass pump flow rate during deep hypothermia. Association between CBV and bypass pump flow rate suggests loss of cerebrovascular autoregulatory processes. Quantitative monitoring of cerebral perfusion by UPD could provide a direct parameter to optimize CPB flow rate.

Epinephrine Dosing Use During Extracorporeal Cardiopulmonary Resuscitation: Single-Center Retrospective Cohort.

OBJECTIVES: During pediatric cardiac arrest, contemporary guidelines recommend dosing epinephrine at regular intervals, including in patients requiring extracorporeal membrane oxygenation (ECMO). The impact of epinephrine-induced vasoconstriction on systemic afterload and venoarterial ECMO support is not well-defined. DESIGN: Nested retrospective observational study within a single center. The primary exposure was time from last dose of epinephrine to initiation of ECMO flow; secondary exposures included cumulative epinephrine dose and arrest time. Systemic afterload was assessed by mean arterial pressure and use of systemic vasodilator therapy; ECMO pump flow and Vasoactive-Inotrope Score (VIS) were used as measures of ECMO support. Clearance of lactate was followed post-cannulation as a marker of systemic perfusion. SETTING: PICU and cardiac ICU in a quaternary-care center. PATIENTS: Patients 0-18 years old who required ECMO cannulation during resuscitation over the 6 years, 2014-2020. Patients were excluded if ECMO was initiated before cardiac arrest or if the resuscitation record was incomplete. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 92 events in 87 patients, with 69 events having complete data for analysis. The median (interquartile range) of total epinephrine dosing was 65 mcg/kg (37-101 mcg/kg), with the last dose given 6 minutes (2-16 min) before the initiation of ECMO flows. Shorter interval between last epinephrine dose and ECMO initiation was associated with increased use of vasodilators within 6 hours of ECMO ( p = 0.05), but not with mean arterial pressure after 1 hour of support (estimate, -0.34; p = 0.06). No other associations were identified between epinephrine delivery and mean arterial blood pressure, vasodilator use, pump speed, VIS, or lactate clearance. CONCLUSIONS: There is limited evidence to support the idea that regular dosing of epinephrine during cardiac arrest is associated with increased in afterload after ECMO cannulation. Additional studies are needed to validate findings against ECMO flows and clinically relevant outcomes.

Anti-SARS-CoV-2 mRNA vaccines as inducers of humoral response against apolipoprotein A-1?

BACKGROUND: COVID-19 and some anti-SARS-CoV-2 vaccines trigger a humoral autoimmune response against a broad range of endogenous components, which may affect recipients' prognosis in predisposed individuals. Autoantibodies directed against apolipoprotein A-1 (AAA1 IgG) the major protein fraction of High Density Lipoprotein have been shown to be raised in COVID-19 and in rheumatoid arthritis (RA) patients and other populations where they have been associated with poorer outcomes. We wanted to assess the impact of anti-SARS-CoV-2 mRNA-based vaccination on AAA1 autoimmune biomarkers in RA patients. METHODS: 20 healthy controls and 77 RA mRNA-based vaccinated patients were collected at baseline, 3 weeks after the first vaccination, 2 and 8 weeks after the second vaccination. AAA1 and SARS-CoV-2 serologies were measured by immunoassays. Systemic and local symptoms occurring during the vaccination protocol were recorded. RESULTS: mRNA-based vaccination induced a significant increase in median AAA1 IgG levels in both healthy controls and RA patients overtime. However, in both populations, these medians trend did not translate into significant increase in AAA1 IgG seropositivity rates despite evolving from 5 to 10% in healthy controls, and from 9 to 12.9% in RA patients. No associations were retrieved between AAA1 IgG and symptoms of any kind during the vaccination protocol. CONCLUSIONS: mRNA-based vaccination seems to induce a light AAA1 IgG response in immunocompetent individuals within 2 months after the last injection. Although we did not observe any warning signs, the formal demonstration of the harmlessness of such biological warrants further studies.

Haemodynamics and cerebral oxygenation of neonatal piglets in the immediate ex utero period supported by mechanical ventilation or ex utero oxygenator.

KEY POINTS: The margin of human viability has extended to the extremes of gestational age (<24 weeks) when the lungs are immature and ventilator-induced lung injury is common. Artificial placenta technology aims to extend gestation ex utero in order to allow the lungs additional time to develop prior to entering an air-breathing environment. We compared the haemodynamics and cerebral oxygenation of piglets in the immediate period post-oxygenator (OXY) transition against both paired in utero measures and uniquely against piglets transitioned onto mechanical ventilation (VENT). Post-transition, OXY piglets became hypotensive with reduced carotid blood flow in comparison with both paired in utero measures and VENT piglets. The addition of a pump to the oxygenator circuit may be required to ensure haemodynamic stability in the immediate post-transition period. ABSTRACT: Gestational age at birth is a major predictor of wellbeing; the lower the gestational age, the greater the risk of mortality and morbidity. At the margins of human viability (<24 weeks gestation) immature lungs combined with the need for early ventilatory support means lung injury and respiratory morbidity is common. The abrupt haemodynamic changes consequent on birth may also contribute to preterm-associated brain injury, including intraventricular haemorrhage. Artificial placenta technology aims to support oxygenation, haemodynamic stability and ongoing fetal development ex utero until mature enough to safely transition to a true ex utero environment. We aimed to characterize the impact of birth transition onto either an oxygenator circuit or positive pressure ventilation on haemodynamic and cerebral oxygenation of the neonatal piglet. At 112 days gestation (term = 115 days), fetal pigs underwent instrumentation surgery and transitioned onto either an oxygenator (OXY, n = 5) or ventilatory support (VENT, n = 8). Blood pressure (BP), carotid blood flow and cerebral oxygenation in VENT piglets rose from in utero levels to be significantly higher than OXY piglets post-transition. OXY piglet BP, carotid blood flow and carotid oxygen delivery (DO2 ) decreased from in utero levels post-transition; however, cerebral regional oxygen saturation (rSO2 ) was maintained at fetal-like levels. OXY piglets became hypoxaemic and retained CO2 . Whether OXY piglets are able to maintain cerebral rSO2 under these conditions for a prolonged period is yet to be determined. Improvements to OXY piglet oxygenation may lie in maintaining piglet BP at in utero levels and enhancing oxygenator circuit flow.

Surgical Closure of Atrial Septal Defects in Young Children-A Review of Anesthesia Care in Sternotomy and Thoracotomy Approaches.

OBJECTIVES: To review and compare the anesthetic management of atrial septal defect (ASD) closures via mini lateral thoracotomy and sternotomy approaches. DESIGN: Retrospective analysis. SETTING: Single- center pediatric quaternary care hospital. PARTICIPANTS: Patients aged <8 years of age undergoing ASD closure. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: Outcome measures included anesthetic technique, total amount and type of analgesics, pain scores, procedure duration, complications, blood transfusion requirements, and duration of stay. Each group had 15 patients. All patients in the sternotomy group received 0.25% bupivacaine subcutaneous infiltration. Eleven of the 15 thoracotomy patients received a fascial plane block, including serratus anterior and erector spinae blocks, and 3 received subcutaneous infiltration. There was no difference in opioid consumption intraoperatively or in the first 24 hours after surgery (0.28 ± 0.24 mg/kg morphine equivalents in thoracotomy group and 0.21 ± 0.12 mg/kg in sternotomy group). Duration of procedure and cardiopulmonary bypass duration were longer in the thoracotomy group. There was no difference in cross-clamp duration between groups. There was no difference in intensive care unit or hospital stay. CONCLUSIONS: The authors reviewed perioperative pain management strategies used in surgical ASD closures. Different fascial plane blocks were used. This study has paved way to design a randomized control trial to compare various regional techniques for cardiac surgeries and identified opportunities for improved pain assessment scoring in children after cardiac surgery.

Anomalous origins of the coronary arteries: current knowledge and future perspectives.

PURPOSE OF REVIEW: The purpose of this review is to survey the contemporary literature surrounding congenital anomalies of origin of the coronary arteries and to identify remaining gaps in knowledge. RECENT FINDINGS: In recent years, lineage tracing analyses and mechanistic studies in model organisms have enhanced our understanding of the normal embryologic development of the coronary arteries, and how disruption of this intricate process can lead to congenital coronary anomalies. The true incidence of these anomalies remains unknown. Although a majority of cases are believed to be clinically silent, clinical presentation varies widely, from asymptomatic to sudden cardiac death. Cardiac computed tomography angiography and/or magnetic resonance angiography are the mainstay diagnostic modalities. Management of anomalous coronary arteries depends on the morphology and clinical presentation. Surgery is the gold-standard treatment for anomalous left coronary artery arising from the pulmonary artery and anomalous aortic origin of a coronary artery with intramural or interarterial course. SUMMARY: Several large multicenter initiatives are currently underway and should help address some of the numerous knowledge gaps surrounding the evaluation and management of anomalous coronary arteries.

A child with a stroke, drug-refractory epilepsy and congenital heart disease: can a hemispherectomy be safely performed between staged cardiac procedures?

BACKGROUND: The safety of hemispherectomy between staged cardiac procedures is unknown and not previously reported. METHOD: Retrospective review of a case with drug-resistant epilepsy due to stroke following bidirectional cavopulmonary connection (BDCPC). RESULTS: This report describes the first case of a successful pediatric peri-insular functional hemispherectomy in the setting of a BDCPC. A discussion of the complex preoperative planning from both a cardiac and neurological perspective is presented. Considerations regarding hemispherectomy and its effects on the cardiac physiology, and perioperative considerations are emphasized in clinical decision making. CONCLUSIONS: A multidisciplinary approach was critical in this child which led to a successful outcome.

Impacts of early cardiac catheterization for children with congenital heart disease supported by extracorporeal membrane oxygenation.

BACKGROUND: Cardiac catheterization is often required for patients on extracorporeal membranous oxygenation (ECMO) support, though its efficacy remains unclear. This study aimed to assess the impact of catheterization on successful ECMO weaning. METHODS: This is a single-center retrospective study from 2000 to 2014. Patients with congenital heart disease who underwent cardiac catheterization while on cardiac ECMO support were included. Logistic regression analysis and Kaplan-Meier survival analysis with log-rank test were performed to determine predictors for successful weaning and patient outcome. RESULTS: Forty-nine catheterizations in 47 patients with the median age of 65 days (range: 1 day-12 years) and the median body weight of 4.2 kg (range: 1.9-32.7 kg) were included. Median duration between ECMO cannulation and catheterization was 1 day (range: 0-11 days). Thirty-three patients (70%) succeeded in decannulation and 24 patients (51%) survived to hospital discharge. Absence of renal (P = 0.045) and respiratory complications (P = 0.031) were significant prognostic factors for successful weaning in multivariate analysis. Patients who received catheterization within 48 hr after ECMO cannulation demonstrated less respiratory complications (P = 0.006) and better survival at 30 days after ECMO initiation (P = 0.039) than those who underwent later catheterization. There was no mortality; however, nine major catheterization-related complications (18%) were detected. CONCLUSION: Catheterization for pediatric patients on ECMO support can be performed, although this group contained high risk of serious adverse events. The absence of ECMO complications is a predictor for successful weaning. An earlier catheterization appears to be associated with better short-term survival in this cohort. © 2016 Wiley Periodicals, Inc.

Impella 5.0 as a Second-Line Mechanical Circulatory Support Strategy After Extracorporeal Life Support.

The catheter-based Impella 5.0 left ventricular assist device is a powerful and less invasive alternative for patients in cardiogenic shock. The use as second-line therapy in patients with precedent extracorporeal life support (ECLS) has not been described before now. We analyzed our experience of consecutive patients treated with this alternative strategy. From April 2014 to December 2014, eight patients had been implanted as a second-line option after ECLS support. The reason for the change from ECLS to Impella 5.0 was absence of cardiac recovery for primary weaning and complications of ECLS therapy. The mean time of ECLS support prior to Impella implantation was 12 ± 7 days. The implantation of the Impella 5.0/CP was technically successful in all patients, and the ECLS could be explanted in all eight patients who received Impella implantation as a second-line treatment. The second-line Impella 5.0 therapy resulted in two patients who turned into left ventricular assist device (LVAD) candidates, two primary weaning candidates, and four patients who died in the setting of sepsis or absent cardiac recovery and contraindications for durable LVAD therapy. Thereby, the overall hospital discharge survival as well as the 180-day survival was 50% for Impella 5.0 implantations as second-line procedure after ECLS. The latest follow-up survival of this second-line strategy after ECLS was three out of eight, as one patient died after 299 days of LVAD support due to sepsis. The use of Impella 5.0 constitutes a possible second-line therapeutic option for those patients who do not show cardiac recovery during prolonged ECLS support or suffer from complications of ECLS therapy. This treatment allows additional time for decisions regarding cardiac recovery or indication for durable LVAD therapy.

Impella 5.0 Support in INTERMACS II Cardiogenic Shock Patients Using Right and Left Axillary Artery Access.

The catheter-based Impella 5.0 left ventricular assist device (LVAD) is a powerful and less invasive alternative for patients in cardiogenic shock. The use of this device as a primary mechanical circulatory support strategy in INTERMACS II patients should be evaluated. From April 2014 to August 2014, eight Impella 5.0 devices were implanted in seven patients via the axillary artery access (six right and two left). We analyzed the outcome of the four patients in whom the Impella 5.0 device was implanted for the purpose of primary stabilization of cardiogenic shock (INTERMACS II). The remaining three patients had a contraindication for a permanent LVAD and received the device for prolonged weaning from extracorporeal life support (ECLS) system. The implantation of the Impella 5.0 was technically successful in all patients and resulted in the stabilization of the clinical situation. All four patients could be bridged to a long-term device (n = 3) or to cardiac recovery (n = 1). In one patient, 2 days of ECLS support was necessary because of pump thrombosis after 31 days of Impella 5.0 support. One patient with bronchopneumonia had the Impella 5.0 exchanged from the right to the left axillary artery after 22 days of support because of the progressive loss of purge flow and the need for longer bridging to a permanent LVAD. The last patient was supported for giant-cell myocarditis for 22 days and bridged to cardiac recovery. All patients were transferred to the intensive care unit with the Impella device in place. In INTERMACS II situations, the implantation of the Impella 5.0 via the right or left axillary access allowed additional time for decision making. Early patient mobilization, including walking with the Impella device in place, optimized the conditions for either weaning or the implantation of a permanent LVAD. This novel technique of left axillary approach leads to more flexibility in the case of anatomical- or device-related contraindications to right-side access, or when the device needs to be exchanged while continuous support is necessary.

Hemocompatibility of Axial Versus Centrifugal Pump Technology in Mechanical Circulatory Support Devices.

The hemocompatible properties of rotary blood pumps commonly used in mechanical circulatory support (MCS) are widely unknown regarding specific biocompatibility profiles of different pump technologies. Therefore, we analyzed the hemocompatibility indicating markers of an axial flow and a magnetically levitated centrifugal device within an in vitro mock loop. The HeartMate II (HM II; n = 3) device and a CentriMag (CM; n = 3) adult pump were investigated in a human whole blood mock loop for 360 min using the MCS devices as a driving component. Blood samples were analyzed by enzyme-linked immunosorbent assay for markers of coagulation, complement system, and inflammatory response. There was a time-dependent activation of the coagulation (thrombin-antithrombin complexes [TAT]), complement (SC5b-9), and inflammation system (polymorphonuclear [PMN] elastase) in both groups. The mean value of TAT (CM: 4.0 µg/L vs. 29.4 µg/L, P < 0.001; HM II: 4.5 µg/L vs. 232.2 µg/L, P < 0.05) and PMN elastase (CM: 53.4 ng/mL vs. 253.8 ng/mL, P < 0.05; HM II: 28.0 ng/mL vs. 738.8 ng/mL, P < 0.001) significantly increased from baseline until the end of the experiments (360 min). After 360 min, TAT and PMN values were significantly higher in the HM II group compared with the values in the CM adult group. The values of SC5b-9 increased from baseline to 360 min in the CM group (CM: 141.8 ng/mL vs. 967.9 ng/mL, P < 0.05) and the HM II group. However, the increase within the HM II group (97.3 vs. 2462.0, P = 0.06) and the comparison of the 360-min values between CM group and HM II group did not reach significance (P = 0.18). The activation of complement, coagulation, and inflammation system showed a time-dependent manner in both devices. The centrifugal CM device showed significantly lower activation of coagulation and inflammation than that of the HM II axial flow pump. Both HM II and CM have demonstrated an acceptable hemocompatibility profile in patients. However, there is a great opportunity to gain a clinical benefit by developing techniques to lower the blood surface interaction within both pump technologies and a magnetically levitated centrifugal pump design might be superior.

Superior cavopulmonary shunt via right vertical axillary mini-thoracotomy.

We present 2 cases of patients with univentricular heart physiology of different anatomic variants who successfully underwent minimally invasive bidirectional cavopulmonary anastomosis via the right vertical axillary mini-thoracotomy.

Coronary artery lesions are associated with adverse cardiac events in children undergoing supravalvular aortic stenosis repair.

OBJECTIVES: The aim of this study was to identify the prevalence and anatomic characteristics of coronary artery lesions and their associated postoperative risk in patients undergoing supravalvular aortic stenosis repair. METHODS: The association between structural risk factors, postoperative ST-segment changes, and major adverse cardiac events was explored using logistic regression and the Fisher's exact test. RESULTS: In 51 consecutive patients with supravalvular aortic stenosis treated between 2000 and 2017, a total of 48 coronary lesions were identified in 27 patients (53%). Prominent ostial ridge (type I) was the most common coronary lesion, followed by small ostium with (IIIb) or without (IIIa) diffuse long-segment coronary narrowing, and adhesion of the coronary cusp (type II). There were 54 concomitant coronary procedures, including 43 primary corrections and 11 revisions. Thirty-three patients underwent supravalvular aortic stenosis repair with a bifurcated patch, of which 13 (39.4%) had right coronary artery distortion/kinking requiring patch plication (n = 8) and reimplantation (n = 5). Postoperative major adverse cardiac events (MACE) occurred in 9 patients (17.6%), including 3 deaths, 4 needing mechanical circulatory support, and 6 experiencing ventricular arrhythmias. Twenty-two patients (43.1%) had postoperative ST-segment changes, including 13 early changes that resolved within 24 h and 9 persistent changes lasting >24 h. Patients with type III lesions were associated with postoperative persistent ST-segment change (P = 0.04) and these lesions independently predicted postoperative MACE (P = 0.02). Patients with pre-existing coronary lesions were at elevated risk of right coronary artery distortion/kinking (P = 0.045). CONCLUSIONS: The prevalence of ST-segment changes and MACE is high in patients undergoing supravalvular aortic stenosis repair. The preoperative presence of complex coronary lesions is the most important predictor for postoperative major adverse cardiac events.

Early outcomes of moderate-to-high-risk pediatric congenital cardiac surgery and predictors of extracorporeal circulatory life support requirement.

Background: Cardiopulmonary failure refractory to medical management after moderate-to-high-risk congenital cardiac surgery may necessitate mechanical support with veno-arterial extracorporeal membrane oxygenation (ECMO). On the extreme, ECMO can also be initiated in the setting of cardiac arrest (extracorporeal cardiopulmonary resuscitation, ECPR) unresponsive to conventional resuscitative measures. Methods: This was a single-center retrospective cohort study of patients (n = 510) aged <3 years old who underwent cardiac surgery with cardiopulmonary bypass with a RACHS-1 score ≥3 between 2011 and 2014. Perioperative factors were reviewed to identify predictors of ECMO initiation and mortality in the operating room (OR) and the intensive care unit (ICU). Results: A total of 510 patients with a mean surgical age of 10.0 ± 13.4 months were included. Among them, 21 (4%) patients received postoperative ECMO-12 were initiated in the OR and 9 in the ICU. ECMO cannulation was associated with cardiopulmonary bypass duration, aortopulmonary shunt, residual severe mitral regurgitation, vaso-inotropic score, and postprocedural lactate (p < 0.001). Of the 32 (6%) total deaths, 7 (22%) were ECMO patients-4 were elective OR cannulations and 3 were ICU ECPR. Prematurity [hazard ratio (HR): 2.61, p < 0.01), Norwood or Damus-Kaye-Stansel procedure (HR: 4.29, p < 0.001), postoperative left ventricular dysfunction (HR: 5.10, p = 0.01), residual severe tricuspid regurgitation (HR: 6.06, p < 0.001), and postoperative ECMO (ECPR: HR: 15.42, p < 0.001 vs. elective: HR: 5.26, p = 0.01) were associated with mortality. The two patients who were electively cannulated in the ICU survived. Discussion: Although uncommon, postoperative ECMO in children after congenital cardiac surgery is associated with high mortality, especially in cases of ECPR. Patients with long cardiopulmonary bypass time, residual cardiac lesions, or increased vaso-inotropic requirement are at higher risk of receiving ECMO. Pre-emptive or early ECMO initiation before deterioration into cardiac arrest may improve survival.

Longitudinal Evaluation of Congenital Cardiovascular Surgical Performance and Skills Retention Using Silicone-Molded Heart Models.

Objective: Hands-on surgical training (HOST) for congenital heart surgery (CHS), utilizing silicone-molded models created from 3D-printing of patients' imaging data, was shown to improve surgical skills. However, the impact of repetition and frequency of repetition in retaining skills has not been previously investigated. We aimed to longitudinally evaluate the outcome for HOST on two example procedures of different technical difficulties with repeated attempts over a 15-week period. Methods: Five CHS trainees were prospectively recruited. Repair of coarctation of the aorta (CoA) and arterial switch operation (ASO) were selected as example procedures of relatively low and high technical difficulty. Procedural time and technical performance (using procedure-specific assessment tools by the participant, a peer-reviewer, and the proctor) were measured. Results: Coarctation repair performance scores improved after the first repetition but remained unchanged at the follow-up session. Likewise, CoA procedural time showed an early reduction but then remained stable (mean [standard deviation]: 29[14] vs 25[15] vs 23[9] min at 0, 1, and 4 weeks). Conversely, ASO performance scores improved during the first repetitions, but decreased after a longer time delay (>9 weeks). Arterial switch operation procedural time showed modest improvements across simulations but significantly reduced from the first to the last attempt: 119[20] versus 106[28] min at 0 and 15 weeks, P = .049. Conclusions: Complex procedures require multiple HOST repetitions, without excessive time delay to maintain long-term skills improvement. Conversely, a single session may be planned for simple procedures to achieve satisfactory medium-term results. Importantly, a consistent reduction in procedural times was recorded, supporting increased surgical efficiency.

Surgical Melody Mitral Valve: A Paradigm Shift for Infants With Unrepairable Mitral Valve Disease.

BACKGROUND: The Melody valve (Medtronic, Minneapolis, MN) for mitral valve replacement (MVR) (MelodyMVR) has been an effective strategy to treat unrepairable mitral valve disease in small children. This study analyzed survival, durability, and complications of the MelodyMVR strategy. METHODS: Patients who underwent MelodyMVR between 2014 and 2023 were included. Transplant-free survival was analyzed with Kaplan-Meier analysis. The Fine and Gray subdistribution method was applied to quantify the cumulative incidence. RESULTS: Twenty-five patients underwent MelodyMVR. Median age and weight were 6.3 months (interquartile range, 4.4-15.2 months) and 6.36 kg (interquartile range, 4.41-7.57 kg). Fifteen patients (60%) had congenital mitral valve disease and 13 (52%) had dominant mitral regurgitation. The median diameter of the implanted Melody was 16 mm (interquartile range, 14-18 mm). Mortality at 6 months, 1 year, and 5 years was 8.3% (95% CI, 2.2%-29.4%), 12.5% (95% CI, 4.2%-33.9%), and 17.6% (95% CI, 7.0%-40.7%), respectively. Two hospital survivors (8%) required early Melody replacement. Competing risk analysis showed that ∼50% of patients underwent mechanical MVR by 3.5 years after MelodyMVR. Freedom from bleeding and thrombosis at 4 years was 87.5% (95% CI, 74.2%-100%). Eleven patients underwent subsequent mechanical MVR with no deaths. One (9%) required pacemaker implantation after mechanical MVR. CONCLUSIONS: MelodyMVR provides reasonable early and medium-term survival in small children and a high rate of successful bridge to mechanical MVR. MelodyMVR is associated with minimal pacemaker requirement, bleeding, and thrombosis. Early Melody functional deterioration necessitates early repeat MVR, which can be achieved with minimal morbidity and mortality.