An IL-1ß-driven neutrophil-stromal cell axis fosters a BAFF-rich protumor microenvironment in individuals with multiple myeloma.

Human bone marrow permanently harbors high numbers of neutrophils, and a tumor-supportive bias of these cells could significantly impact bone marrow-confined malignancies. In individuals with multiple myeloma, the bone marrow is characterized by inflammatory stromal cells with the potential to influence neutrophils. We investigated myeloma-associated alterations in human marrow neutrophils and the impact of stromal inflammation on neutrophil function. Mature neutrophils in myeloma marrow are activated and tumor supportive and transcribe increased levels of IL1B and myeloma cell survival factor TNFSF13B (BAFF). Interactions with inflammatory stromal cells induce neutrophil activation, including BAFF secretion, in a STAT3-dependent manner, and once activated, neutrophils gain the ability to reciprocally induce stromal activation. After first-line myeloid-depleting antimyeloma treatment, human bone marrow retains residual stromal inflammation, and newly formed neutrophils are reactivated. Combined, we identify a neutrophil-stromal cell feed-forward loop driving tumor-supportive inflammation that persists after treatment and warrants novel strategies to target both stromal and immune microenvironments in multiple myeloma.

The multiple myeloma microenvironment is defined by an inflammatory stromal cell landscape.

Progression and persistence of malignancies are influenced by the local tumor microenvironment, and future eradication of currently incurable tumors will, in part, hinge on our understanding of malignant cell biology in the context of their nourishing surroundings. Here, we generated paired single-cell transcriptomic datasets of tumor cells and the bone marrow immune and stromal microenvironment in multiple myeloma. These analyses identified myeloma-specific inflammatory mesenchymal stromal cells, which spatially colocalized with tumor cells and immune cells and transcribed genes involved in tumor survival and immune modulation. Inflammatory stromal cell signatures were driven by stimulation with proinflammatory cytokines, and analyses of immune cell subsets suggested interferon-responsive effector T cell and CD8+ stem cell memory T cell populations as potential sources of stromal cell-activating cytokines. Tracking stromal inflammation in individuals over time revealed that successful antitumor induction therapy is unable to revert bone marrow inflammation, predicting a role for mesenchymal stromal cells in disease persistence.

Paediatric aortic valve replacement: a meta-analysis and microsimulation study.

AIMS: To support decision-making in children undergoing aortic valve replacement (AVR), by providing a comprehensive overview of published outcomes after paediatric AVR, and microsimulation-based age-specific estimates of outcome with different valve substitutes. METHODS AND RESULTS: A systematic review of published literature reporting clinical outcome after paediatric AVR (mean age <18 years) published between 1/1/1990 and 11/08/2021 was conducted. Publications reporting outcome after paediatric Ross procedure, mechanical AVR (mAVR), homograft AVR (hAVR), and/or bioprosthetic AVR were considered for inclusion. Early risks (<30d), late event rates (>30d) and time-to-event data were pooled and entered into a microsimulation model. Sixty-eight studies, of which one prospective and 67 retrospective cohort studies, were included, encompassing a total of 5259 patients (37 435 patient-years; median follow-up: 5.9 years; range 1-21 years). Pooled mean age for the Ross procedure, mAVR, and hAVR was 9.2 ± 5.6, 13.0 ± 3.4, and 8.4 ± 5.4 years, respectively. Pooled early mortality for the Ross procedure, mAVR, and hAVR was 3.7% (95% CI, 3.0%-4.7%), 7.0% (5.1%-9.6%), and 10.6% (6.6%-17.0%), respectively, and late mortality rate was 0.5%/year (0.4%-0.7%/year), 1.0%/year (0.6%-1.5%/year), and 1.4%/year (0.8%-2.5%/year), respectively. Microsimulation-based mean life-expectancy in the first 20 years was 18.9 years (18.6-19.1 years) after Ross (relative life-expectancy: 94.8%) and 17.0 years (16.5-17.6 years) after mAVR (relative life-expectancy: 86.3%). Microsimulation-based 20-year risk of aortic valve reintervention was 42.0% (95% CI: 39.6%-44.6%) after Ross and 17.8% (95% CI: 17.0%-19.4%) after mAVR. CONCLUSION: Results of paediatric AVR are currently suboptimal with substantial mortality especially in the very young with considerable reintervention hazards for all valve substitutes, but the Ross procedure provides a survival benefit over mAVR. Pros and cons of substitutes should be carefully weighed during paediatric valve selection.

The Dutch national paediatric heart transplantation programme: outcomes during a 23-year period.

BACKGROUND: Since 1998, there has been a national programme for paediatric heart transplantations (HT) in the Netherlands. In this study, we investigated waiting list mortality, survival post-HT, the incidence of common complications, and the patients' functional status during follow-up. METHODS: All children listed for HT from 1998 until October 2020 were included. Follow-up lasted until 1 January 2021. Data were collected from the patient charts. Survival, post-operative complications as well as the functional status (Karnofsky/Lansky scale) at the end of follow-up were measured. RESULTS: In total, 87 patients were listed for HT, of whom 19 (22%) died while on the waiting list. Four patients were removed from the waiting list and 64 (74%) underwent transplantation. Median recipient age at HT was 12.0 (IQR 7.2-14.4) years old; 55% were female. One-, 5­, and 10-year survival post-HT was 97%, 95%, and 88%, respectively. Common transplant-related complications were rejections (50%), Epstein-Barr virus infections (31%), cytomegalovirus infections (25%), post-transplant lymphoproliferative disease (13%), and cardiac allograft vasculopathy (13%). The median functional score (Karnofsky/Lansky scale) was 100 (IQR 90-100). CONCLUSION: Children who undergo HT have an excellent survival rate up to 10 years post-HT. Even though complications post-HT are common, the functional status of most patients is excellent. Waiting list mortality is high, demonstrating that donor availability for this vulnerable patient group remains a major limitation for further improvement of outcome.

Staged correction of pulmonary atresia, ventricular septal defect, and collateral arteries.

OBJECTIVES: Pulmonary atresia (PA) with ventricular septal defect (VSD) and systemic-pulmonary collateral arteries (SPCAs) presents with variable anatomy with regard to the pulmonary vasculature, requiring personalized surgical treatment. A protocol consisting of staged unifocalization and correction was employed. METHODS: Since 1989, 39 consecutive patients were included (median age at first operation 13 months). In selected cases, a central aorto-pulmonary shunt was performed as the first procedure. Unifocalization procedures were performed through a lateral thoracotomy. Correction consisted of shunt takedown, VSD closure, and interposition of an allograft between the right ventricle and the reconstructed pulmonary artery. Echocardiographic data were obtained postoperatively and at interval follow-up. RESULTS: In 39 patients 66 unifocalization procedures were performed. Early mortality was 5%. Seven patients were considered not suitable for correction, of which four have since died. One patient is awaiting further correction. A correction was performed successfully in 28 patients. Operative mortality was 3% and late mortality was 11%. Median follow-up after the correction was 19 years. Eleven patients required homograft replacement. Freedom from conduit replacement was 88%, 73%, and 60% at 5, 10, and 15 years respectively. Right ventricular function was reasonable or good in 75% of patients. All but one patient were in NYHA Class I or II. CONCLUSIONS: After complete unifocalization 30/37 patients (81%) were considered correctable. The staged approach of PA, VSD, and SPCAs results in adequate correction and good functional capacity. RV function after correction remains reasonable or good in the majority of patients.

Cyanosis due to an isolated atrial septal defect: case report and review of the literature.

Isolated atrial defects usually lead to left-to-right shunt and right ventricular volume load. Descriptions of cyanosis with this congenital heart defect are rare.We describe a rare case of inferior caval vein flow directed through an atrial septal defect in the fossa ovalis leading to severe cyanosis, but without any additional intracardiac anatomical abnormalities. The baby with clinical features of Marfan's syndrome had an eventration of the right-sided diaphragm. Surgical closure of the defect resolved the cyanosis, but the child died 10 weeks later of severe valvar dysfunction, related to Marfan's syndrome.Mechanisms of cyanosis in patients with atrial septal defects are discussed. Echocardiographic bubble studies both from the lower and upper half of the body may help to clarify the mechanism of an otherwise unexplained cyanosis.

Transthoracic access for pulmonary artery stenting.

Pulmonary artery stenting may not be possible transcutaneously because of anatomic features. Although intraoperative stenting has been well described, we present a case in which stenting of the left pulmonary artery was performed transthoracically in a separate procedure. Unusual anatomic conditions may require a multi-disciplinary hybrid approach to achieve the desired results.

Renal function at 1 year after cardiac transplantation rather than acute kidney injury is highly associated with long-term patient survival and loss of renal function - a retrospective cohort study.

This study aimed to assess the association between acute kidney injury (AKI), renal function 1 year after transplantation, and long-term adverse outcomes after cardiac transplantation. A retrospective cohort study was performed including 471 adult cardiac transplantation recipients that survived the first postoperative year between 1984 and 2012. Primary outcome variables were long-term overall and renal survival. During the first postoperative week, 40% (n = 188) of the recipients developed AKI stage I, 22% (n = 104) stage II, and 13% (n = 63) stage III, and 4% (n = 17) required temporary renal replacement therapy (RRT). No crude association was found between the development of AKI and long-term mortality (P = 0.50) or chronic RRT dependence (P = 0.27). In multivariable analysis, only AKI requiring RRT was associated with an increased risk for mortality (HR = 2.59, 95% CI = 1.17-5.73) and chronic RRT dependence (HR = 13.14, 95% CI = 3.26-52.92). While less severe episodes of AKI did not affect the recipient's long-term prognosis, renal function 1 year after transplantation had a strong association with long-term outcome. An eGFR <30 ml/min/1.73 was independently associated with mortality (HR = 2.69, 95% CI = 1.68-4.32) and an eGFR <60 ml/min/1.73 with chronic RRT dependence (eGFR 30-59: HR = 3.57, 95% CI = 1.41-9.01; eGFR <30: HR = 16.53, 95% CI = 5.72-47.78). In conslusion, besides AKI requiring RRT, less severe episodes of AKI have limited implications for the recipient's prognosis and long-term outcome after cardiac transplantation is strongly determined by the degree of renal impairment 1 year after transplantation.

"Thunderstruck": penetrating thoracic injury from lightning strike.

Lightning strike victims are rarely presented at an emergency department. Burns are often the primary focus. This case report describes the improvised explosive device like-injury to the thorax due to lightning strike and its treatment, which has not been described prior in (kerauno)medicine. Penetrating injury due to blast from lightning strike is extremely rare. These "shrapnel" injuries should however be ruled out in all patients struck by lightning.

Long-term surgical outcomes of congenital supravalvular aortic stenosis: a systematic review, meta-analysis and microsimulation study.

OBJECTIVES: Congenital supravalvular aortic stenosis (SVAS) is a rare form of congenital outflow tract obstruction and long-term outcomes are scarcely reported. This study aims to provide an overview of outcomes after surgical repair for congenital SVAS. METHODS: A systematic review of published literature was conducted, including observational studies reporting long-term clinical outcome (>2 years) after SVAS repair in children or adults considering >20 patients. Early risks, late event rates and time-to-event data were pooled and entered into a microsimulation model to estimate 30-year outcomes. Life expectancy was compared to the age-, sex- and origin-matched general population. RESULTS: Twenty-three publications were included, encompassing a total of 1472 patients (13 125 patient-years; pooled mean follow-up: 9.0 (6.2) years; median follow-up: 6.3 years). Pooled mean age at surgical repair was 4.7 (5.8) years and the most commonly used surgical technique was the single-patch repair (43.6%). Pooled early mortality was 4.2% (95% confidence interval: 3.2-5.5%) and late mortality was 0.61% (95% CI: 0.45-0.83) per patient-year. Based on microsimulation, over a 30-year time horizon, it was estimated that an average patient with SVAS repair (mean age: 4.7 years) had an observed life expectancy that was 90.7% (95% credible interval: 90.0-91.6%) of expected life expectancy in the matched general population. The microsimulation-based 30-year risk of myocardial infarction was 8.1% (95% credible interval: 7.3-9.9%) and reintervention 31.3% (95% credible interval: 29.6-33.4%), of which 27.2% (95% credible interval: 25.8-29.1) due to repair dysfunction. CONCLUSIONS: After surgical repair for SVAS, 30-year survival is lower than the matched-general-population survival and the lifetime risk of reintervention is considerable. Therefore, lifelong monitoring of the cardiovascular system and in particular residual stenosis and coronary obstruction is recommended.

Clinical Course of TGA After Arterial Switch Operation in the Current Era.

Background: The number of patients with an arterial switch operation (ASO) for transposition of the great arteries (TGA) is steadily growing; limited information is available regarding the clinical course in the current era. Objectives: The purpose was to describe clinical outcome late after ASO in a national cohort, including survival, rates of (re-)interventions, and clinical events. Methods: A total of 1,061 TGA-ASO patients (median age 10.7 years [IQR: 2.0-18.2 years]) from a nationwide prospective registry with a median follow-up of 8.0 years (IQR: 5.4-8.8 years) were included. Using an analysis with age as the primary time scale, cumulative incidence of survival, (re)interventions, and clinical events were determined. Results: At the age of 35 years, late survival was 93% (95% CI: 88%-98%). The cumulative re-intervention rate at the right ventricular outflow tract and pulmonary branches was 36% (95% CI: 31%-41%). Other cumulative re-intervention rates at 35 years were on the left ventricular outflow tract (neo-aortic root and valve) 16% (95% CI: 10%-22%), aortic arch 9% (95% CI: 5%-13%), and coronary arteries 3% (95% CI: 1%-6%). Furthermore, 11% (95% CI: 6%-16%) of the patients required electrophysiological interventions. Clinical events, including heart failure, endocarditis, and myocardial infarction occurred in 8% (95% CI: 5%-11%). Independent risk factors for any (re-)intervention were TGA morphological subtype (Taussig-Bing double outlet right ventricle [HR: 4.9, 95% CI: 2.9-8.1]) and previous pulmonary artery banding (HR: 1.6, 95% CI: 1.0-2.2). Conclusions: TGA-ASO patients have an excellent survival. However, their clinical course is characterized by an ongoing need for (re-)interventions, especially on the right ventricular outflow tract and the left ventricular outflow tract indicating a strict lifelong surveillance, also in adulthood.

Aortic valve repair in neonates, infants and children: a systematic review, meta-analysis and microsimulation study.

OBJECTIVES: To support clinical decision-making in children with aortic valve disease, by compiling the available evidence on outcome after paediatric aortic valve repair (AVr). METHODS: A systematic review of literature reporting clinical outcome after paediatric AVr (mean age at surgery <18 years) published between 1 January 1990 and 23 December 2021 was conducted. Early event risks, late event rates and time-to-event data were pooled. A microsimulation model was employed to simulate the lives of individual children, infants and neonates following AVr. RESULTS: Forty-one publications were included, encompassing 2 623 patients with 17 217 patient-years of follow-up (median follow-up: 7.3 years; range: 1.0-14.4 years). Pooled mean age during repair for aortic stenosis in children (<18 years), infants (<1 year) or neonates (<30 days) was 5.2 ± 3.9 years, 35 ± 137 days and 11 ± 6 days, respectively. Pooled early mortality after stenosis repair in children, infants and neonates, respectively, was 3.5% (95% confidence interval: 1.9-6.5%), 7.4% (4.2-13.0%) and 10.7% (6.8-16.9%). Pooled late reintervention rate after stenosis repair in children, infants and neonates, respectively, was 3.31%/year (1.66-6.63%/year), 6.84%/year (3.95-11.83%/year) and 6.32%/year (3.04-13.15%/year); endocarditis 0.07%/year (0.03-0.21%/year), 0.23%/year (0.07-0.71%/year) and 0.49%/year (0.18-1.29%/year); and valve thrombosis 0.05%/year (0.01-0.26%/year), 0.15%/year (0.04-0.53%/year) and 0.19%/year (0.05-0.77%/year). Microsimulation-based mean life expectancy in the first 20 years for children, infants and neonates with aortic stenosis, respectively, was 18.4 years (95% credible interval: 18.1-18.7 years; relative survival compared to the matched general population: 92.2%), 16.8 years (16.5-17.0 years; relative survival: 84.2%) and 15.9 years (14.8-17.0 years; relative survival: 80.1%). Microsimulation-based 20-year risk of reintervention in children, infants and neonates, respectively, was 75.2% (72.9-77.2%), 53.8% (51.9-55.7%) and 50.8% (47.0-57.6%). CONCLUSIONS: Long-term outcomes after paediatric AVr for stenosis are satisfactory and dependent on age at surgery. Despite a high hazard of reintervention for valve dysfunction and slightly impaired survival relative to the general population, AVr is associated with low valve-related event occurrences and should be considered in children with aortic valve disease.

In-vivo Sino-Atrial Node Mapping in Children and Adults With Congenital Heart Disease.

Background: Sinus node dysfunction (SND) and atrial tachyarrhythmias frequently co-exist in the aging patient with congenital heart disease (CHD), even after surgical correction early in life. We examined differences in electrophysiological properties of the sino-atrial node (SAN) area between pediatric and adult patients with CHD. Methods: Epicardial mapping of the SAN was performed during sinus rhythm in 12 pediatric (0.6 [0.4-2.4] years) and 15 adult (47 [40-55] years) patients. Unipolar potentials were classified as single-, short or long double- and fractionated potentials. Unipolar voltage, relative R-to-S-amplitude ratio and duration of all potentials was calculated. Conduction velocity (CV) and the amount of conduction block (CB) was calculated. Results: SAN activity in pediatric patients was solely observed near the junction of the superior caval vein and the right atrium, while in adults SAN activity was observed even up to the middle part of the right atrium. Compared to pediatric patients, the SAN region of adults was characterized by lower CV, lower voltages, more CB and a higher degree of fractionation. At the earliest site of activation, single potentials from pediatrics consisted of broad monophasic S-waves with high amplitudes, while adults had smaller rS-potentials with longer duration which were more often fractionated. Conclusions: Compared to pediatric patients, adults with uncorrected CHD have more inhomogeneous conduction and variations in preferential SAN exit site, which are presumable caused by aging related remodeling. Long-term follow-up of these patients is essential to demonstrate whether these changes are related to development of SND and also atrial tachyarrhythmias early in life.

Long-term outcomes of atrioventricular septal defect and single ventricle: A multicenter study.

OBJECTIVE: The study objective was to analyze survival and incidence of Fontan completion of patients with single-ventricle and concomitant unbalanced atrioventricular septal defect. METHODS: Data from 4 Dutch and 3 Belgian institutional databases were retrospectively collected. A total of 151 patients with single-ventricle atrioventricular septal defect were selected; 36 patients underwent an atrioventricular valve procedure (valve surgery group). End points were survival, incidence of Fontan completion, and freedom from atrioventricular valve reoperation. RESULTS: Median follow-up was 13.4 years. Cumulative survival was 71.2%, 70%, and 68.5% at 10, 15, and 20 years, respectively. An atrioventricular valve procedure was not a risk factor for mortality. Patients with moderate-severe or severe atrioventricular valve regurgitation at echocardiographic follow-up had a significantly worse 15-year survival (58.3%) compared with patients with no or mild regurgitation (89.2%) and patients with moderate regurgitation (88.6%) (P = .033). Cumulative incidence of Fontan completion was 56.5%, 71%, and 77.6% at 5, 10, and 15 years, respectively. An atrioventricular valve procedure was not associated with the incidence of Fontan completion. In the valve surgery group, freedom from atrioventricular valve reoperation was 85.7% at 1 year and 52.6% at 5 years. CONCLUSIONS: The long-term survival and incidence of Fontan completion in our study were better than previously described for patients with single-ventricle atrioventricular septal defect. A concomitant atrioventricular valve procedure did not increase the mortality rate or decrease the incidence of Fontan completion, whereas patients with moderate-severe or severe valve regurgitation at follow-up had a worse survival. Therefore, in patients with single-ventricle atrioventricular septal defect when atrioventricular valve regurgitation exceeds a moderate degree, the atrioventricular valve should be repaired.

Homograft durability after correction of pulmonary atresia and ventricular septal defect with or without systemic pulmonary collateral arteries.

Background: Pulmonary atresia and ventricular septal defect (PA-VSD), with or without systemic pulmonary collateral arteries (SPCAs), represents a complex anatomic and surgical spectrum of congenital heart disease. Currently, there is limited evidence on homograft durability after complete correction, which potentially could be affected by anatomic differences in pulmonary vasculature. Methods: This retrospective single-center study included all 69 consecutive PA-VSD patients (46 with SPCAs, 23 without SPCAs) operated on between 1978 and 2018. The primary interest was in homograft durability after complete repair. Longitudinal echocardiographic homograft function and right ventricular systolic pressure were analyzed with linear mixed-effects models. Results: The median duration of follow-up was 20 years. Of the 46 patients with SPCAs, 37 (80.4%) underwent biventricular correction at a median age of 2.7 years (interquartile range [IQR], 1.8-6.3 years). Two patients are currently awaiting unifocalization and correction. All 23 patients without SPCAs underwent successful complete correction at a median age of 1.6 years (IQR, 1.1-3.6 years). Freedom from any reintervention after 20 years was 15%. When a homograft was used during correction, freedom from homograft replacement after 20 years was comparable in the 2 groups (P = .925), at 32 ± 11% in the SPCA group and 32 ± 13% in the non-SPCA group. Indications for homograft replacement were isolated stenosis (n = 7; 46.7%), isolated regurgitation (n = 3; 20.0%), and mixed stenosis and regurgitation (n = 5; 33.3%) in the SPCA group and isolated stenosis (n = 8; 88.9%) and stenosis and regurgitation (n = 1; 11.1%) in the non-SPCA group. Peak homograft gradient was significantly (P = .0003) higher in patients without SPCA, with a comparable rate of progression in the 2 groups. However, the prevalence of severe pulmonary regurgitation (PR) was higher in patients with SPCAs, estimated at 35% at 10 years, compared with 15% in patients without SPCAs. Conclusions: Homografts used for right ventricular outflow tract reconstruction in patients with PA-VSD, either with or without SPCAs, have similar limited durability. Repeated reintervention is common, and careful follow-up with attention to severe PR is warranted.

3D Virtual Reality Imaging of Major Aortopulmonary Collateral Arteries: A Novel Diagnostic Modality.

BACKGROUND: Major aortopulmonary collateral arteries (MAPCAs), as seen in patients with pulmonary atresia, are arteries that supply blood from the aorta to the lungs and often require surgical intervention. To achieve complete repair in the least number of interventions, optimal imaging of the pulmonary arterial anatomy and MAPCAs is critical. 3D virtual reality (3D-VR) is a promising and upcoming new technology that could potentially ameliorate current imaging shortcomings. METHODS: A retrospective, proof-of-concept study was performed of all operated patients with pulmonary atresia and MAPCAs at our center between 2010 and 2020 with a preoperative computed tomography (CT) scan. CT images were reviewed by two congenital cardiac surgeons in 3D-VR to determine additional value of VR for MAPCA imaging compared to conventional CT and for preoperative planning of MAPCA repair. RESULTS: 3D-VR visualizations were reconstructed from CT scans of seven newborns where the enhanced topographic anatomy resulted in improved visualization of MAPCA. In addition, surgical planning was improved since new observations or different preoperative plans were apparent in 4 out of 7 cases. After the initial setup, VR software and hardware was reported to be easy and intuitive to use. CONCLUSIONS: This study showed technical feasibility of 3D-VR reconstruction of children with immersive visualization of topographic anatomy in an easy-to-use format leading to an improved surgical planning of MAPCA surgery. Future prospective studies are required to investigate the clinical benefits in larger populations.

Unusual Hybrid Closure of Ventricular Septal Defects.

A planned combined perventricular and "open heart" surgical closure of multiple ventricular septal defects had to be modified intraoperatively due to a technical fault disabling echocardiographic guidance. Through an atriotomy, device closure of a muscular defect and patch closure of a perimembranous ventricular septal defect were performed. In unusual situations, collaboration of the surgical and interventional team is crucial.

An unusual case of redo tricuspid valve replacement and repair of a previously unidentified anomalous pulmonary venous return in a patient with congenitally corrected transposition of the great arteries.

Associated cardiovascular malformations in congenitally corrected transposition of the great arteries (CCTGA) should not be missed when a patient requires surgical correction. We present a case of an adult CCTGA patient who required redo surgery for recurrent tricuspid (left atrioventricular) valve regurgitation and previously unidentified partial anomalous pulmonary venous return.

Outcome after surgical repair of tetralogy of Fallot: A systematic review and meta-analysis.

INTRODUCTION: Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease. Intracardiac correction was pioneered by Walton Lillehei in 1955 and has since then gone through major developments. The aim of this study was to provide a systematic literature review of published results on the long-term outcome of complete surgical correction of TOF. METHODS: MEDLINE, PubMed, Embase, Web of Science, Cochrane, and Google Scholar were systematically searched for literature published between January 2000 and July 2018. Pooled estimates with a random effects model after log-transformation were calculated for mortality and reintervention. Potential heterogeneity was assessed by subgroup analyses and meta-regression. RESULTS: A total of 143 papers of 137 distinct cohorts comprising 21,427 patients and total follow-up duration of 147,430 patient-years were included. Overall mean age at correction was 3.7 ± 5.6 years, but excluding papers exclusively focusing on correction in adults yielded a mean age of 0.5 ± 2.5 years at correction. Previous palliative shunts (107 studies), a transventricular approach (81 studies), and a transannular patch (124 studies) were used in 16% (range 0%-78%), 39% (range 0%-100%), and 49% (range 0%-100%) of the patients. respectively. In case a transannular patch was used, monocusp reconstruction was applied in 15% (range 0%-100%) (49 studies). The most common genetic abnormality was Down syndrome, with a pooled estimated prevalence of 4.6% (range 0%-12.3%). The pooled estimates of early and late mortality were 2.84% (95% confidence interval [CI], 2.34-3.45) and 0.42%/year (95% CI, 0.33-0.54), respectively. The pooled estimate of late cardiac mortality was 0.26%/year (95% CI, 0.21-0.34). Valve-related mortality and non-valve-related mortality had pooled estimates of 0.20%/year (95% CI, 0.15-0.26) and 0.17%/year (95% CI, 0.12-0.22), respectively. The pooled estimate of reintervention was 2.26%/year (95% CI, 1.86-2.75). CONCLUSIONS: TOF can be surgically corrected at a young age with low perioperative and long-term mortality. Life-long intensive follow-up and substantial reintervention rates characterize the clinical course.