Prospective evaluation of acute neurological events after paediatric cardiac surgery.

OBJECTIVES: Children with CHD are at heightened risk of neurodevelopmental problems; however, the contribution of acute neurological events specifically linked to the perioperative period is unclear. AIMS: This secondary analysis aimed to quantify the incidence of acute neurological events in a UK paediatric cardiac surgery population, identify risk factors, and assess how acute neurological events impacted the early post-operative pathway. METHODS: Post-operative data were collected prospectively on 3090 consecutive cardiac surgeries between October 2015 and June 2017 in 5 centres. The primary outcome of analysis was acute neurological event, with secondary outcomes of 6-month survival and post-operative length of stay. Patient and procedure-related variables were described, and risk factors were statistically explored with logistic regression. RESULTS: Incidence of acute neurological events after paediatric cardiac surgery in our population occurred in 66 of 3090 (2.1%) consecutive cardiac operations. 52 events occurred with other morbidities including renal failure (21), re-operation (20), cardiac arrest (20), and extracorporeal life support (18). Independent risk factors for occurrence of acute neurological events were CHD complexity 1.9 (1.1-3.2), p = 0.025, longer operation times 2.7 (1.6-4.8), p < 0.0001, and urgent surgery 3.4 (1.8-6.3), p < 0.0001. Unadjusted comparison found that acute neurological event was linked to prolonged post-operative hospital stay (median 35 versus 9 days) and poorer 6-month survival (OR 13.0, 95% CI 7.2-23.8). CONCLUSION: Ascertainment of acute neurological events relates to local measurement policies and was rare in our population. The occurrence of acute neurological events remains a suitable post-operative metric to follow for quality assurance purposes.

Rapid desensitization through immunoadsorption during cardiopulmonary bypass. A novel method to facilitate human leukocyte antigen incompatible heart transplantation.

BACKGROUND: Anti-human leukocyte antigen (HLA)-antibody production represents a major barrier to heart transplantation, limiting recipient compatibility with potential donors and increasing the risk of complications with poor waiting-list outcomes. Currently there is no consensus to when desensitization should take place, and through what mechanism, meaning that sensitized patients must wait for a compatible donor for many months, if not years. We aimed to determine if intraoperative immunoadsorption could provide a potential desensitization methodology. METHODS: Anti-HLA antibody-containing whole blood was added to a Cardiopulmonary bypass (CPB) circuit set up to mimic a 20 kg patient undergoing heart transplantation. Plasma was separated and diverted to a standalone, secondary immunoadsorption system, with antibody-depleted plasma returned to the CPB circuit. Samples for anti-HLA antibody definition were taken at baseline, when combined with the CPB prime (on bypass), and then every 20 min for the duration of treatment (total 180 min). RESULTS: A reduction in individual allele median fluorescence intensity (MFI) to below clinically relevant levels (<1000 MFI), and in the majority of cases below the lower positive detection limit (<500 MFI), even in alleles with a baseline MFI >4000 was demonstrated. Reduction occurred in all cases within 120 min, demonstrating efficacy in a time period usual for heart transplantation. Flowcytometric crossmatching of suitable pseudo-donor lymphocytes demonstrated a change from T cell and B cell positive channel shifts to negative, demonstrating a reduction in binding capacity. CONCLUSIONS: Intraoperative immunoadsorption in an ex vivo setting demonstrates clinically relevant reductions in anti-HLA antibodies within the normal timeframe for heart transplantation. This method represents a potential desensitization technique that could enable sensitized children to accept a donor organ earlier, even in the presence of donor-specific anti-HLA antibodies.

A Review of Endogenous and Exogenous Contrast Agents Used in Photoacoustic Tomography with Different Sensing Configurations.

Optical-based sensing approaches have long been an indispensable way to detect molecules in biological tissues for various biomedical research and applications. The advancement in optical microscopy is one of the main drivers for discoveries and innovations in both life science and biomedical imaging. However, the shallow imaging depth due to the use of ballistic photons fundamentally limits optical imaging approaches' translational potential to a clinical setting. Photoacoustic (PA) tomography (PAT) is a rapidly growing hybrid imaging modality that is capable of acoustically detecting optical contrast. PAT uniquely enjoys high-resolution deep-tissue imaging owing to the utilization of diffused photons. The exploration of endogenous contrast agents and the development of exogenous contrast agents further improve the molecular specificity for PAT. PAT's versatile design and non-invasive nature have proven its great potential as a biomedical imaging tool for a multitude of biomedical applications. In this review, representative endogenous and exogenous PA contrast agents will be introduced alongside common PAT system configurations, including the latest advances of all-optical acoustic sensing techniques.

Tri-modality in vivo imaging for tumor detection with combined ultrasound, photoacoustic, and photoacoustic elastography.

A comprehensive understanding of a tumor is required for accurate diagnosis and effective treatment. However, currently, there is no single imaging modality that can provide sufficient information. Photoacoustic (PA) imaging is a hybrid imaging technique with high spatial resolution and detection sensitivity, which can be combined with ultrasound (US) imaging to provide both optical and acoustic contrast. Elastography can noninvasively map the elasticity distribution of biological tissue, which reflects pathological conditions. In this study, we incorporated PA elastography into a commercial US/PA imaging system to develop a tri-modality imaging system, which has been tested for tumor detection using four mice with different physiological conditions. The results show that this tri-modality imaging system can provide complementary information on acoustic, optical, and mechanical properties. The enabled visualization and dimension estimation of tumors can lead to a more comprehensive tissue characterization for diagnosis and treatment.

Deep learning-assisted smartphone-based quantitative microscopy for label-free peripheral blood smear analysis.

Hematologists evaluate alterations in blood cell enumeration and morphology to confirm peripheral blood smear findings through manual microscopic examination. However, routine peripheral blood smear analysis is both time-consuming and labor-intensive. Here, we propose using smartphone-based autofluorescence microscopy (Smart-AM) for imaging label-free blood smears at subcellular resolution with automatic hematological analysis. Smart-AM enables rapid and label-free visualization of morphological features of normal and abnormal blood cells (including leukocytes, erythrocytes, and thrombocytes). Moreover, assisted with deep-learning algorithms, this technique can automatically detect and classify different leukocytes with high accuracy, and transform the autofluorescence images into virtual Giemsa-stained images which show clear cellular features. The proposed technique is portable, cost-effective, and user-friendly, making it significant for broad point-of-care applications.

Use of diagnostic information submitted to the United Kingdom Central Cardiac Audit Database: development of categorisation and allocation algorithms.

OBJECTIVE: To categorise records according to primary cardiac diagnosis in the United Kingdom Central Cardiac Audit Database in order to add this information to a risk adjustment model for paediatric cardiac surgery. DESIGN: Codes from the International Paediatric Congenital Cardiac Code were mapped to recognisable primary cardiac diagnosis groupings, allocated using a hierarchy and less refined diagnosis groups, based on the number of functional ventricles and presence of aortic obstruction. SETTING: A National Clinical Audit Database. Patients Children undergoing cardiac interventions: the proportions for each diagnosis scheme are presented for 13,551 first patient surgical episodes since 2004. RESULTS: In Scheme 1, the most prevalent diagnoses nationally were ventricular septal defect (13%), patent ductus arteriosus (10.4%), and tetralogy of Fallot (9.5%). In Scheme 2, the prevalence of a biventricular heart without aortic obstruction was 64.2% and with aortic obstruction was 14.1%; the prevalence of a functionally univentricular heart without aortic obstruction was 4.3% and with aortic obstruction was 4.7%; the prevalence of unknown (ambiguous) number of ventricles was 8.4%; and the prevalence of acquired heart disease only was 2.2%. Diagnostic groups added to procedural information: of the 17% of all operations classed as "not a specific procedure", 97.1% had a diagnosis identified in Scheme 1 and 97.2% in Scheme 2. CONCLUSIONS: Diagnostic information adds to surgical procedural data when the complexity of case mix is analysed in a national database. These diagnostic categorisation schemes may be used for future investigation of the frequency of conditions and evaluation of long-term outcome over a series of procedures.

Oxygen delivery in pediatric cardiac surgery and its association with acute kidney injury using machine learning.

OBJECTIVE: Acute kidney injury (AKI) after pediatric cardiac surgery with cardiopulmonary bypass (CPB) is a frequently reported complication. In this study we aimed to determine the oxygen delivery indexed to body surface area (Do2i) threshold associated with postoperative AKI in pediatric patients during CPB, and whether it remains clinically important in the context of other known independent risk factors. METHODS: A single-institution, retrospective study, encompassing 396 pediatric patients, who underwent heart surgery between April 2019 and April 2021 was undertaken. Time spent below Do2i thresholds were compared to determine the critical value for all stages of AKI occurring within 48 hours of surgery. Do2i threshold was then included in a classification analysis with known risk factors including nephrotoxic drug usage, surgical complexity, intraoperative data, comorbidities and ventricular function data, and vasoactive inotrope requirement to determine Do2i predictive importance. RESULTS: Logistic regression models showed cumulative time spent below a Do2i value of 350 mL/min/m2 was associated with AKI. Random forest models, incorporating established risk factors, showed Do2i threshold still maintained predictive importance. Patients who developed post-CPB AKI were younger, had longer CPB and ischemic times, and required higher inotrope support postsurgery. CONCLUSIONS: The present data support previous findings that Do2i during CPB is an independent risk factor for AKI development in pediatric patients. Furthermore, the data support previous suggestions of a higher threshold value in children compared with that in adults and indicate that adjustments in Do2i management might reduce incidence of postoperative AKI in the pediatric cardiac surgery population.

Cardiomyocyte Ca2+ handling and structure is regulated by degree and duration of mechanical load variation.

Cardiac transverse (t)-tubules are altered during disease and may be regulated by stretch-sensitive molecules. The relationship between variations in the degree and duration of load and t-tubule structure remains unknown, as well as its implications for local Ca(2+)-induced Ca(2+) release (CICR). Rat hearts were studied after 4 or 8 weeks of moderate mechanical unloading [using heterotopic abdominal heart-lung transplantation (HAHLT)] and 6 or 10 weeks of pressure overloading using thoracic aortic constriction. CICR, cell and t-tubule structure were assessed using confocal-microscopy, patch-clamping and scanning ion conductance microscopy. Moderate unloading was compared with severe unloading [using heart-only transplantation (HAHT)]. Mechanical unloading reduced cardiomyocyte volume in a time-dependent manner. Ca(2+) release synchronicity was reduced at 8 weeks moderate unloading only. Ca(2+) sparks increased in frequency and duration at 8 weeks of moderate unloading, which also induced t-tubule disorganization. Overloading increased cardiomyocyte volume and disrupted t-tubule morphology at 10 weeks but not 6 weeks. Moderate mechanical unloading for 4 weeks had milder effects compared with severe mechanical unloading (37% reduction in cell volume at 4 weeks compared to 56% reduction after severe mechanical unloading) and did not cause depression and delay of the Ca(2+) transient, increased Ca(2+) spark frequency or impaired t-tubule and cell surface structure. These data suggest that variations in chronic mechanical load influence local CICR and t-tubule structure in a time- and degree-dependent manner, and that physiological states of increased and reduced cell size, without pathological changes are possible.

Tricuspid valve repair in single ventricle: timing and techniques.

Tricuspid valve performance in the systemic circulation is known to have important implications for survival and functional status after univentricular palliation of hypoplastic left heart syndrome (HLHS). Moderate to severe tricuspid valve regurgitation is not an uncommon finding in patients with HLHS undergoing staged surgical reconstruction. It can result from either abnormal valve morphology or incomplete leaflet coaptation, or both. But first and foremost, any aortic arch re-obstruction must be excluded. Development of significant tricuspid regurgitation (TR) remains an obstacle in improving survival after the Norwood procedure and likely compromised functional health after the Fontan procedure. Thus, surgical intervention for minimizing tricuspid valve deterioration and significant TR seems pivotal to improving long-term outcomes for patients with HLHS. This article provides an overview of the etiology and mechanisms of development of significant TR, natural history, indications for surgical intervention, and focuses on timing, techniques, and clinical outcomes of tricuspid valve repair in the setting of single ventricle.

Rapid slide-free and non-destructive histological imaging using wide-field optical-sectioning microscopy.

Histopathology based on formalin-fixed and paraffin-embedded tissues has long been the gold standard for surgical margin assessment (SMA). However, routine pathological practice is lengthy and laborious, failing to guide surgeons intraoperatively. In this report, we propose a practical and low-cost histological imaging method with wide-field optical-sectioning microscopy (i.e., High-and-Low-frequency (HiLo) microscopy). HiLo can achieve rapid and non-destructive imaging of freshly-excised tissues at an extremely high acquisition speed of 5 cm2/min with a spatial resolution of 1.3 µm (lateral) and 5.8 µm (axial), showing great potential as an SMA tool that can provide immediate feedback to surgeons and pathologists for intraoperative decision-making. We demonstrate that HiLo enables rapid extraction of diagnostic features for different subtypes of human lung adenocarcinoma and hepatocellular carcinoma, producing surface images of rough specimens with large field-of-views and cellular features that are comparable to the clinical standard. Our results show promising clinical translations of HiLo microscopy to improve the current standard of care.

High-Speed Ultraviolet Photoacoustic Microscopy for Histological Imaging with Virtual-Staining assisted by Deep Learning.

Surgical margin analysis (SMA), an essential procedure to confirm the complete excision of cancerous tissue in tumor resection surgery, requires intraoperative diagnostic tools to avoid repeated surgeries due to a positive surgical margin. Recently, by taking the advantage of the high intrinsic optical absorption of DNA/RNA at 266 nm wavelength, ultraviolet photoacoustic microscopy (UV-PAM) has been developed to provide high-resolution histological images without labeling, showing great promise as an intraoperative tool for SMA. To enable the development of UV-PAM for SMA, here, a high-speed and open-top UV-PAM system is presented, which can be operated similarly to conventional optical microscopies. The UV-PAM system provides a high lateral resolution of 1.2 µm, and a high imaging speed of 55 kHz A-line rate with one-axis galvanometer mirror scanning. Moreover, to ensure UV-PAM images can be easily interpreted by pathologists without additional training, the original grayscale UV-PAM images are virtually stained by a deep-learning algorithm to mimic the standard hematoxylin- and eosin-stained images, enabling training-free histological analysis. Mouse brain slice imaging is performed to demonstrate the high performance of the open-top UV-PAM system, illustrating its great potential for SMA applications.

Three-dimensional label-free histological imaging of whole organs by microtomy-assisted autofluorescence tomography.

Three-dimensional (3D) histology is vitally important to characterize disease-induced tissue heterogeneity at the individual cell level. However, it remains challenging for both high-throughput 3D imaging and volumetric reconstruction. Here we propose a label-free, cost-effective, and ready-to-use 3D histological imaging technique, termed microtomy-assisted autofluorescence tomography with ultraviolet excitation (MATE). With the combination of block-face imaging and serial microtome sectioning, MATE can achieve rapid and label-free imaging of paraffin-embedded whole organs at an acquisition speed of 1 cm3 per 4 h with a voxel resolution of 1.2 × 1.2 × 10 µm3. We demonstrate that MATE enables simultaneous visualization of cell nuclei, fiber tracts, and blood vessels in mouse/human brains without tissue staining or clearing. Moreover, diagnostic features, including nuclear size and packing density, can be quantitatively extracted with high accuracy. MATE is augmented to the current slide-based 2D histology, holding great promise to facilitate histopathological interpretation at the organelle level.

Low-cost high-resolution photoacoustic microscopy of blood oxygenation with two laser diodes.

Optical-resolution photoacoustic microscopy (OR-PAM) has been widely used for imaging blood vessel and oxygen saturation of hemoglobin (sO2), providing high-resolution functional images of living animals in vivo. However, most of them require one or multiple bulky and costly pulsed lasers, hindering their applicability in preclinical and clinical settings. In this paper, we demonstrate a reflection-mode low-cost high-resolution OR-PAM system by using two cost-effective and compact laser diodes (LDs), achieving microvasculature and sO2 imaging with a high lateral resolution of ∼6 µm. The cost of the excitation sources has dramatically reduced by ∼20-40 times compared to that of the pulsed lasers used in state-of-the-art OR-PAM systems. A blood phantom study was performed to show a determination coefficient R 2 of 0.96 in linear regression analysis. Experimental results of in vivo mouse ear imaging show that the proposed dual-wavelength LD-based PAM system can provide high-resolution functional images at a low cost.

Translational rapid ultraviolet-excited sectioning tomography for whole-organ multicolor imaging with real-time molecular staining.

Rapid multicolor three-dimensional (3D) imaging for centimeter-scale specimens with subcellular resolution remains a challenging but captivating scientific pursuit. Here, we present a fast, cost-effective, and robust multicolor whole-organ 3D imaging method assisted with ultraviolet (UV) surface excitation and vibratomy-assisted sectioning, termed translational rapid ultraviolet-excited sectioning tomography (TRUST). With an inexpensive UV light-emitting diode (UV-LED) and a color camera, TRUST achieves widefield exogenous molecular-specific fluorescence and endogenous content-rich autofluorescence imaging simultaneously while preserving low system complexity and system cost. Formalin-fixed specimens are stained layer by layer along with serial mechanical sectioning to achieve automated 3D imaging with high staining uniformity and time efficiency. 3D models of all vital organs in wild-type C57BL/6 mice with the 3D structure of their internal components (e.g., vessel network, glomeruli, and nerve tracts) can be reconstructed after imaging with TRUST to demonstrate its fast, robust, and high-content multicolor 3D imaging capability. Moreover, its potential for developmental biology has also been validated by imaging entire mouse embryos (~2 days for the embryo at the embryonic day of 15). TRUST offers a fast and cost-effective approach for high-resolution whole-organ multicolor 3D imaging while relieving researchers from the heavy sample preparation workload.

Ultraviolet photoacoustic microscopy with tissue clearing for high-contrast histological imaging.

Ultraviolet photoacoustic microscopy (UV-PAM) has been investigated to provide label-free and registration-free volumetric histological images for whole organs, offering new insights into complex biological organs. However, because of the high UV absorption of lipids and pigments in tissue, UV-PAM suffers from low image contrast and shallow image depth, hindering its capability for revealing various microstructures in organs. To improve the UV-PAM imaging contrast and imaging depth, here we propose to implement a state-of-the-art optical clearing technique, CUBIC (clear, unobstructed brain/body imaging cocktails and computational analysis), to wash out the lipids and pigments from tissues. Our results show that the UV-PAM imaging contrast and quality can be significantly improved after tissue clearing. With the cleared tissue, multilayers of cell nuclei can also be extracted from time-resolved PA signals. Tissue clearing-enhanced UV-PAM can provide fine details for organ imaging.

Lessons from inter-stage cardiac magnetic resonance imaging in predicting survival for patients with hypoplastic left heart syndrome.

UNLABELLED: This study describes single-unit experience and explores risk stratification, with protocolised inter-stage cardiac magnetic resonance imaging for infants with hypoplastic left heart syndrome. Survival was retrospectively analysed among the cohort of locally followed survivors of Norwood Stage I procedure, who underwent magnetic resonance imaging under general anaesthesia from 2003 to 2008. This included 32 patients: 17 with Sano conduit and 15 with arterio-pulmonary shunt. The median (inter-quartile range) age and weight at scan were 3.1 (2.6-4.6) months and 5.0 (4.5-5.3) kilograms, respectively. Using morphologic definitions, the median coarctation index was 0.71 (0.57-0.83). The degree of proximal right and left pulmonary artery narrowing was 25% (14-44%) and 25% (11-50%), respectively. The median right ventricular ejection fraction was 54% (48-59%). The ejection fraction was not related to the coarctation index or to pulmonary artery narrowing. Patients were followed up for a median of 19.2 (10.8-46.0) months, during which 13 (41%) had an intervention in addition to routine Norwood Stage II surgery and seven died. Risk of death was related to reduced right ventricular ejection fraction, with a hazard ratio of 0.91 (95% confidence interval 0.85-0.98, p = 0.02), and the cumulative number of focal stenoses of neo-aortic arch and pulmonary arteries (hazard ratio 2.71, 95% confidence interval 1.14-6.44, p = 0.02). CONCLUSIONS: In addition to comprehensive three-dimensional morphologic imaging, inter-stage cardiac magnetic resonance imaging provides a ventricular functional index that may predict outcome in patients with hypoplastic left heart syndrome. Measures to preserve right ventricular systolic function and relieve stenoses are paramount within the complex management strategies for these patients.

High-speed high-resolution laser diode-based photoacoustic microscopy for in vivo microvasculature imaging.

Laser diodes (LDs) have been considered as cost-effective and compact excitation sources to overcome the requirement of costly and bulky pulsed laser sources that are commonly used in photoacoustic microscopy (PAM). However, the spatial resolution and/or imaging speed of previously reported LD-based PAM systems have not been optimized simultaneously. In this paper, we developed a high-speed and high-resolution LD-based PAM system using a continuous wave LD, operating at a pulsed mode, with a repetition rate of 30 kHz, as an excitation source. A hybrid scanning mechanism that synchronizes a one-dimensional galvanometer mirror and a two-dimensional motorized stage is applied to achieve a fast imaging capability without signal averaging due to the high signal-to-noise ratio. By optimizing the optical system, a high lateral resolution of 4.8 µm has been achieved. In vivo microvasculature imaging of a mouse ear has been demonstrated to show the high performance of our LD-based PAM system.

Cone reconstruction for Ebstein anomaly: Late biventricular function and possible remodeling.

OBJECTIVES: To evaluate late-term tricuspid valve competence and biventricular function following cone reconstruction for Ebstein anomaly, and to explore biventricular remodeling. METHODS: Consecutive adult and pediatric patients who underwent cone reconstruction from 2009 to 2019 were reviewed for inclusion in this retrospective cardiac magnetic resonance imaging study. Tricuspid valve competence was assessed with tricuspid regurgitation fraction. Biventricular systolic function was assessed by ejection fraction, cardiac index, indexed stroke volume, and indexed aortic and pulmonary artery beat volume. Biventricular remodeling was assessed by planimetered areas (right atrium, functional right ventricle, left heart), and indexed end-diastolic and end-systolic ventricular volumes. Paired t tests or Wilcoxon signed-rank tests were used for analyses. RESULTS: Of 58 included patients, 50 underwent cardiac magnetic resonance imaging. Twelve patients had both preoperative and late postoperative cardiac magnetic resonance imaging with a median follow-up of 5.11 years (interquartile range, 3.12-6.07 years). Focusing on these, tricuspid regurgitation fraction decreased (from 69% to 10%; P = .014), right ventricle ejection fraction remained stable, and antegrade pulmonary artery beat volume increased (from 26.7 to 41.6 mL/beat/m2; P = .037). The left ventricle stroke volume (from 30.4 to 44.1 mL/m2; P = .015) and antegrade aortic beat volume (from 28.5 to 41.1 mL/beat/m2; P = .014) also increased, and the left ventricle stroke volume improved progressively with time since surgery (P = .048). Whereas the right atrium area decreased (P = .004), the functional right ventricle and left heart area increased (cm2, P = .021 and P = .004). Right ventricle volumes showed a tendency to normalize and left ventricle indexed end-diastolic volume increased (from 50 to 69 mL/m2; P = .03) over time. CONCLUSIONS: Cone valve integrity was sustained. Biventricular function improved progressively during follow-up, and there are positive signs of biventricular remodeling late after cone reconstruction.

Factors associated with unplanned reinterventions and their relation to early mortality after pediatric cardiac surgery.

OBJECTIVE: Unplanned reintervention (uRE) is used as an indicator of patient morbidity and quality of care in pediatric cardiac surgery. We investigated associated factors and early mortality after uREs. METHODS: Morbidity data were prospectively collected in 5 UK centers between 2015 and 2017; uRE included surgical cardiac, interventional transcatheter cardiac, permanent pacemaker, and diaphragm plication procedures. Mortality (30-day and 6-month) in uRE/no-uRE patients was reported before and after matching. Predicted 30-day mortality was calculated using the Partial Risk Adjustment in Surgery score. RESULTS: A total of 3090 procedures (2861 patients) were included (median age, 228 days). There were 146 uREs, resulting in an uRE rate of 4.7%. Partial Risk Adjustment in Surgery score, 30-day mortality and 6-month mortality in uRE and no-uRE groups were 2.4% versus 1.3%, 8.9% versus 1%, and 17.1% versus 2.4%, respectively. After matching, mortality at 6 months remained higher in uRE compared with no-uRE (12.2% vs 1.4%; P = .02; 74 pairs). In the uRE group, 21 out of 25 deaths at 6 months occurred when at least 1 additional postoperative complication was present. In multivariable analysis, neonatal age (P = .002), low weight (P = .009), univentricular heart (P < .001), and arterial shunt (P < .001) were associated with increased risk of uRE, but Partial Risk Adjustment in Surgery score was not (only in univariable analysis). CONCLUSIONS: uREs are a relatively frequent complication after pediatric cardiac surgery and are associated with some patient characteristics, but not the Partial Risk Adjustment in Surgery risk score. Early mortality was higher after uRE, independent of preoperative factors, but linked to other postoperative complications.

Congenital heart surgery databases around the world: do we need a global database?

The question posed in the title of this article is: "Congenital Heart Surgery Databases Around the World: Do We Need a Global Database?" The answer to this question is "Yes and No"! Yes--we need to create a global database to track the outcomes of patients with pediatric and congenital heart disease. No--we do not need to create a new "global database." Instead, we need to create a platform that allows for the linkage of currently existing continental subspecialty databases (and continental subspecialty databases that might be created in the future) that will allow for the seamless sharing of multi-institutional longitudinal data across temporal, geographical, and subspecialty boundaries. This review article will achieve the following objectives: (A) Consider the current state of analysis of outcomes of treatments for patients with congenitally malformed hearts. (B) Present some principles that might make it possible to achieve life-long longitudinal monitoring and follow-up. (C) Describe the rationale for the creation of a Global Federated Multispecialty Congenital Heart Disease Database. (D) Propose a methodology for the creation of a Global Federated Multispecialty Congenital Heart Disease Database that is based on linking together currently existing databases without creating a new database. To perform meaningful multi-institutional analyses, any database must incorporate the following six essential elements: (1) Use of a common language and nomenclature. (2) Use of a database with an established uniform core dataset for collection of information. (3) Incorporation of a mechanism to evaluate the complexity of cases. (4) Implementation of a mechanism to assure and verify the completeness and accuracy of the data collected. (5) Collaboration between medical and surgical subspecialties. (6) Standardization of protocols for life-long longitudinal follow-up. Analysis of outcomes must move beyond recording 30-day or hospital mortality, and encompass longer-term follow-up, including cardiac and non-cardiac morbidities, and importantly, those morbidities impacting health-related quality of life. Methodologies must be implemented in our databases to allow uniform, protocol-driven, and meaningful long-term follow-up. We need to create a platform that allows for the linkage of currently existing continental subspecialty databases (and continental subspecialty databases that might be created in the future) that will allow for the seamless sharing of multi-institutional longitudinal data across temporal, geographical, and subspecialty boundaries. This "Global Federated Multispecialty Congenital Heart Disease Database" will not be a new database, but will be a platform that effortlessly links multiple databases and maintains the integrity of these extant databases. Description of outcomes requires true multi-disciplinary involvement, and should include surgeons, cardiologists, anesthesiologists, intensivists, perfusionists, neurologists, educators, primary care physicians, nurses, and physical therapists. Outcomes should determine primary therapy, and as such must be monitored life-long. The relatively small numbers of patients with congenitally malformed hearts requires multi-institutional cooperation to accomplish these goals. The creation of a Global Federated Multispecialty Congenital Heart Disease Database that links extant databases from pediatric cardiology, pediatric cardiac surgery, pediatric cardiac anesthesia, and pediatric critical care will create a platform for improving patient care, research, and teaching related to patients with congenital and pediatric cardiac disease.