Modification of the Warden Procedure for Surgical Repair of Partial Anomalous Pulmonary Venous Connection.

Warden procedure is a popular technique for repairing partial anomalous pulmonary venous connection. We describe a modification of this technique for surgical repair of this condition by raising both a superior vena cava (SVC) flap and right atrial appendage flap to create a tension-free SVC-RA continuity (neo-SVC). The anomalous pulmonary veins are routed via the remanent of proximal SVC and baffled to the left atrium across a surgically created or enlarged atrial septal defect using autologous pericardium.

Zoom and its Discontents: Group Decision Making in Pediatric Cardiology in the Time of COVID (and Beyond) : Aurthors.

The emergence of Covid-19 has led to change within hospital-based healthcare. An example, has been to reconfigure clinical decision making meetings from traditional in-person (Face-to-face, FtF) to online video-conferencing (VC) format inorder to decrease contagion risk. Despite its widespread uptake, there is minimal empirical data evaluating this format. This narrative review considers the implications on medical decision-making when clinicians communicate remotely via Microsoft Teams. The discussion is informed by the psychological literature and by commentary obtained from a survey of paediatric cardiac clinicians who participated in clinical meetings when video-conferencing was first introduced. Whist video-conferencing can optimize clinician presence, this is potentially offset by compromises in current imaging quality, the group discussion, information sharing and decision quality. Implementing a shift from face-to-face to VC within the group decision-making process requires an appreciation of the changed environment, appropriate adaptations and the implemention of new technology solutions. Meanwhile, healthcare should carefully consider the potential implications of clinical decision making using online video conferencing, be prepared to adapt and evaluate prior to a shift away from face-to-face formats.

Development of a Semiautomated Database for Patients With Adult Congenital Heart Disease.

BACKGROUND: Databases for Congenital Heart Disease (CHD) are effective in delivering accessible datasets ready for statistical inference. Data collection hitherto has, however, been labour and time intensive and has required substantial financial support to ensure sustainability. We propose here creation and piloting of a semiautomated technique for data extraction from clinic letters to populate a clinical database. METHODS: PDF formatted clinic letters stored in a local folder, through a series of algorithms, underwent data extraction, preprocessing, and analysis. Specific patient information (diagnoses, diagnostic complexity, interventions, arrhythmia, medications, and demographic data) was processed into text files and structured data tables, used to populate a database. A specific data validation schema was predefined to verify and accommodate the information populating the database. Unsupervised learning in the form of a dimensionality reduction technique was used to project data into 2 dimensions and visualize their intrinsic structure in relation to the diagnosis, medication, intervention, and European Society of Cardiology classification lists of disease complexity. Ninety-three randomly selected letters were reviewed manually for accuracy. RESULTS: There were 1409 consecutive outpatient clinic letters used to populate the Scottish Adult Congenital Cardiac Database. Mean patient age was 35.4 years; 47.6% female; with 698 (49.5%) having moderately complex, 369 (26.1%) greatly complex, and 284 (20.1%) mildly complex lesions. Individual diagnoses were successfully extracted in 96.95%, and demographic data were extracted in 100% of letters. Data extraction, database upload, data analysis and visualization took 571 seconds (9.51 minutes). Manual data extraction in the categories of diagnoses, intervention, and medications yielded accuracy of the computer algorithm in 94%, 93%, and 93%, respectively. CONCLUSIONS: Semiautomated data extraction from clinic letters into a database can be achieved successfully with a high degree of accuracy and efficiency.

Fluid-structure interaction in a fully coupled three-dimensional mitral-atrium-pulmonary model.

This paper aims to investigate detailed mechanical interactions between the pulmonary haemodynamics and left heart function in pathophysiological situations (e.g. atrial fibrillation and acute mitral regurgitation). This is achieved by developing a complex computational framework for a coupled pulmonary circulation, left atrium and mitral valve model. The left atrium and mitral valve are modelled with physiologically realistic three-dimensional geometries, fibre-reinforced hyperelastic materials and fluid-structure interaction, and the pulmonary vessels are modelled as one-dimensional network ended with structured trees, with specified vessel geometries and wall material properties. This new coupled model reveals some interesting results which could be of diagnostic values. For example, the wave propagation through the pulmonary vasculature can lead to different arrival times for the second systolic flow wave (S2 wave) among the pulmonary veins, forming vortex rings inside the left atrium. In the case of acute mitral regurgitation, the left atrium experiences an increased energy dissipation and pressure elevation. The pulmonary veins can experience increased wave intensities, reversal flow during systole and increased early-diastolic flow wave (D wave), which in turn causes an additional flow wave across the mitral valve (L wave), as well as a reversal flow at the left atrial appendage orifice. In the case of atrial fibrillation, we show that the loss of active contraction is associated with a slower flow inside the left atrial appendage and disappearances of the late-diastole atrial reversal wave (AR wave) and the first systolic wave (S1 wave) in pulmonary veins. The haemodynamic changes along the pulmonary vessel trees on different scales from microscopic vessels to the main pulmonary artery can all be captured in this model. The work promises a potential in quantifying disease progression and medical treatments of various pulmonary diseases such as the pulmonary hypertension due to a left heart dysfunction.

Outcomes of adults with repaired tetralogy of Fallot from the national Scottish Cohort.

BACKGROUND: The adult population of repaired tetralogy of Fallot is increasing and at risk of pre-mature death and arrhythmia. This study evaluates risk factors for adverse outcome and the effect of pulmonary valve replacement within a national cohort. METHODS: A retrospective cohort study of 341 adult repaired tetralogy of Fallot (16-72 years) managed through a single national service was undertaken incorporating over 1200 patient-years of follow-up. Demographics, cardiopulmonary exercise testing, cardiac magnetic resonance, reintervention (including pulmonary valve replacement), and clinical events were analysed. The influence of these parameters on a primary outcome (death or arrhythmia) was evaluated. RESULTS: Compared with an age-/gender-matched population, patients experienced a reduced survival, particularly males over 55 years (standardised mortality ratio : 6.12, 95% CI: 1.64-15.66, p = 0.004). Cox proportional hazards modelling identified increased indexed right ventricle (RV) end-diastolic volume (hazard ratio (HR): 2.86, 95% CI: 1.4-5.85, p = 0.004) and female gender (HR (male): 0.37, 95% CI: 0.14-0.98, p = 0.045) to be predictors significantly associated with the primary outcome. Pulmonary valve replacement undertaken at indexed RV end-diastolic volume = 145 ml/m2 reduced RV volumes and QRS duration but did not improve cardiopulmonary exercise testing nor NYHA class. Pulmonary valve replacement during cohort period was associated with increased risk of primary outcome (HR: 2.82, 95% CI: 1.36-5.86, p = 0.005). CONCLUSIONS: Although the majority of adult tetralogy of Fallot were asymptomatic in NYHA 1, cardiopulmonary exercise testing revealed important deficits. Tetralogy of Fallot survival was reduced compared to the general population. Female gender and increasing RV end-diastolic volume predicted adverse events. Pulmonary valve replacement reduced RV volumes and QRS duration but did not improve primary outcome.

Blood flow simulations in the pulmonary bifurcation in relation to adult patients with repaired tetralogy of Fallot.

Understanding the haemodynamic environment of the pulmonary bifurcation is important in adults with repaired conotruncal congenital heart disease. In these patients, dysfunction of the pulmonary valve and narrowing of the branch pulmonary arteries are common and can have serious clinical consequences. The aim of this study was to numerically investigate the underlying blood flow characteristics in the pulmonary trunk under a range of simplified conditions. For that, an in-depth analysis was conducted in idealised two-dimensional geometries that facilitate parametric investigation of healthy and abnormal conditions. Subtle variations in morphology influenced the haemodynamic environment and wall shear stress distribution. The pressure in the left pulmonary artery was generally higher than that in the right and main arteries, but was markedly reduced in the presence of a local stenosis. Different downstream pressure conditions altered the branch flow ratio, from 50:50% to more realistic 60:40% ratios in the right and left pulmonary artery, respectively. Despite some simplifications, this study highlights some previously undocumented aspects of the flow in bifurcating geometries, by clarifying the role of the stagnation point location on wall shear stress and differential branch pressures. In addition, measurements of the mean pressure ratios in the pulmonary bifurcation are discussed in the context of a new haemodynamic index which could potentially contribute to the assessment of left pulmonary artery stenosis in tetralogy of Fallot patients. Further studies are required to confirm the results in patient-specific models with personalised physiological flow conditions.

Thoracic aortic surgery: status and upcoming novelties.

Several novel technological developments and surgical approaches have characterized the field of aortic surgery in the recent decade. The progressive introduction of endovascular procedures, minimally invasive surgical techniques and hybrid approaches have changed the practice in aortic surgery and generated new trends and questions. Also, the advancements in the manufacturing of tissue engineered vascular grafts as substitutes for aortic replacements are enlightening new avenues in the treatment of aortic disease. This review will provide an overview of the current novel perspectives, debates and trends in major thoracic aortic surgery.

A Prospective Randomized Blinded Trial of Remote Ischemic Preconditioning in Children Undergoing Cardiac Surgery.

Remote ischemic preconditioning (RIPC) has been proposed as an intervention to protect myocardium and attenuate end-organ dysfunction associated with cardiopulmonary bypass. We investigated the effect of RIPC in children undergoing cardiopulmonary bypass involving clinical outcome, cardiac and end-organ function, inflammatory response, and myocardial gene expression. A prospective, investigator-blinded, randomized, controlled trial was performed. Patients were randomized into RIPC or Control; RIPC consisted of three 5-minute cycles of limb ischemia-reperfusion taking place 1 and 12 hours preoperatively. Clinical outcomes included cardiac function, ICU surveillance, and renal function. In addition, inflammatory markers and myocardial gene expression were evaluated. RIPC patients required shorter ICU stay (days), RIPC: 1.8 (0.94-3.88) vs Control: 4.9 (1.63-7.20), P = 0.029. Echocardiography parameters demonstrated reduced biventricular function following surgery showing no difference between groups. A nonsignificant trend for reduced troponin was observed following RIPC: AUC analysis, RIPC: 393.05 (98.85-1038.73) vs Control: 596.10 (225.38-954.24) P = 0.75. B-type natriuretic peptide and renal function parameters were similar between groups. Postoperative TNF-α was significantly reduced after RIPC, RIPC: 15.42 (7.81-114.86) vs Control: 108.98 (42.28-301.19) P = 0.02. Remaining inflammatory markers demonstrated no significant difference between groups. HSP-60 showed lower myocardial expression following RIPC, RIPC: 3.95 (2.69-6.28) vs Control: 6.83 (4.74-8.81), P = 0.05. Expression of other analyzed genes was not influenced by RIPC. RIPC was associated with shorter ICU stay and reduced TNF-α but did not influence other clinical outcomes, not confer protection against cardiac injury or renal dysfunction. The association between RIPC and ICU stay may be influenced by unaccounted latent variables, including cardiac morphology.

Superior Vena Cava Inflow Following Repair for Anomalous Right Pulmonary Venous Drainage in Children.

Risk of superior vena cava (SVC) obstruction following repair of anomalous right upper pulmonary veins in children is unclear. The incidence and outcome of subclinical obstruction remained unknown. Retrospective single institutional study (07/1993-02/2017) in a pediatric population (N = 42, median age 3.9-year, range 0.1-15.3 years). 33 (79%) children had repair without SVC translocation ("non-Warden") and 9 (21%) had Warden-type surgery. Echocardiographic SVC obstruction was defined as (I) turbulent flow across SVC and (II) continuous flow pattern without return to baseline velocity (0 m/s); severe obstruction was defined as loss of distinct biphasic profile ± mean gradient ≥ 5 mmHg. 3 (7%) patients required intra-operative revision due to obstruction (non-Warden: 1, Warden: 2). After discharge, 2 (5%) patients required reintervention (3 and 6-month post-op) for severe symptomatic obstruction (non-Warden: 1, Warden-type: 1). Both patients responded to balloon angioplasty with symptomatic resolution (one required repeat catheter reintervention). 10 (24%) patients had subclinical echocardiographic obstruction (2, 22% Warden vs. 8, 24% non-Warden; p = 1.0; 8 of 10 patients had mild gradient), which resolved and remained well without reintervention. At follow-up (mean 7.2-year, range 0-23 years), all patients were alive. Freedom from SVC reintervention at 10 and 20-year is 95% (97% at 10, 20-year in non-Warden and 89% at 5, 8-year in Warden-type group; log-rank p = 0.34). Surgical repair for anomalous right upper pulmonary veins is associated with risk of SVC obstruction in children. The need for reintervention for severe obstruction is rare at late follow-up. Patients with subclinical obstruction remain asymptomatic and demonstrate echocardiographic improvement.

Results of international assistance for a paediatric heart surgery programme in a single Ukrainian centre.

BACKGROUND: Surgery for CHD has been slow to develop in parts of the former Soviet Union. The impact of an 8-year surgical assistance programme between an emerging centre and a multi-disciplinary international team that comprised healthcare professionals from developed cardiac programmes is analysed and presented.Material and methodsThe international paediatric assistance programme included five main components - intermittent clinical visits to the site annually, medical education, biomedical engineering support, nurse empowerment, and team-based practice development. Data were analysed from visiting teams and local databases before and since commencement of assistance in 2007 (era A: 2000-2007; era B: 2008-2015). The following variables were compared between periods: annual case volume, operative mortality, case complexity based on Risk Adjustment for Congenital Heart Surgery (RACHS-1), and RACHS-adjusted standardised mortality ratio. RESULTS: A total of 154 RACHS-classifiable operations were performed during era A, with a mean annual case volume by local surgeons of 19.3 at 95% confidence interval 14.3-24.2, with an operative mortality of 4.6% and a standardised mortality ratio of 2.1. In era B, surgical volume increased to a mean of 103.1 annual cases (95% confidence interval 69.1-137.2, p<0.0001). There was a non-significant (p=0.84) increase in operative mortality (5.7%), but a decrease in standardised mortality ratio (1.2) owing to an increase in case complexity. In era B, the proportion of local surgeon-led surgeries during visits from the international team increased from 0% (0/27) in 2008 to 98% (58/59) in the final year of analysis. CONCLUSIONS: The model of assistance described in this report led to improved adjusted mortality, increased case volume, complexity, and independent operating skills.

Extracorporeal membrane oxygenation in pediatric cardiac surgery: A retrospective review of trends and outcomes in Scotland.

INTRODUCTION: Around 3.2%-8.4% of patients receive venoarterial (VA) extracorporeal membrane oxygenation (ECMO) support after pediatric cardiac surgery. The desired outcome is "bridge-to-recovery" in most cases. There is no universally agreed protocol, and given the associated costs and complications rates, the decisions as of when and when not to institute VA ECMO are largely empirical. METHODS: A retrospective review of the ECMO database at the Scottish Pediatric Cardiac Services (SPCS) was undertaken. Inclusion criterion encompassed all children (<16 years of age) who were supported with VA ECMO following cardiac surgery between January 2011 and October 2016. The timing of ECMO support was divided into three distinct phases: "endofcase" or intheatre ECMO for patients unable to effectively wean from cardiopulmonary bypass (CPB), ECMO for cardiopulmonary resuscitation ("ECPR"), and Intensive Care Unit ECMO for "failing maximal medial therapy" following cardiac surgery. The patients were analyzed to identify survival rates, adverse prognostic indicators, and complication rates. RESULTS: We identified 66 patients who met the inclusion criterion. 30day survival rate was 45% and survival rate to hospital discharge was 44% (the difference represents one patient). On followup (median: 960 days, range: 42-2010 days), all survivors to hospital discharge were alive at review date. "End-of-case" ECMO showed a trend toward better survival of the three subcategories ("end of case," ECPR, and ECMO for "failing maximal medical therapy" survival rates were 47%, 41%, and 37.5%, respectively, P = 0.807). The poorest survival rates were in the younger children (<6 months, P = 0.502), patients who had prolonged CPB (P = 0.314) and aortic crossclamp times (P = 0.146), and longer duration of ECMO (>10 days, P = 0.177). CONCLUSIONS: Allcomers VA ECMO following pediatric cardiac surgery had survival to discharge rate of 44%. Elective "end-of-case" ECMO carries better survival rates and therefore ECMO instituted early maybe advantageous. Prolonged ECMO support has a direct correlation with mortality.

Modelling mitral valvular dynamics-current trend and future directions.

Dysfunction of mitral valve causes morbidity and premature mortality and remains a leading medical problem worldwide. Computational modelling aims to understand the biomechanics of human mitral valve and could lead to the development of new treatment, prevention and diagnosis of mitral valve diseases. Compared with the aortic valve, the mitral valve has been much less studied owing to its highly complex structure and strong interaction with the blood flow and the ventricles. However, the interest in mitral valve modelling is growing, and the sophistication level is increasing with the advanced development of computational technology and imaging tools. This review summarises the state-of-the-art modelling of the mitral valve, including static and dynamics models, models with fluid-structure interaction, and models with the left ventricle interaction. Challenges and future directions are also discussed.

Late gadolinium enhancement and adverse outcomes in a contemporary cohort of adult survivors of tetralogy of Fallot.

OBJECTIVE: Myocardial fibrosis has been associated with poorer outcomes in tetralogy of Fallot, however only a handful of studies have assessed its significance in the current era. Our aim was to quantify the amount of late gadolinium enhancement in both the LV and RV in a contemporary cohort of adults with surgically repaired tetralogy of Fallot, and assess the relationship with adverse clinical outcomes. DESIGN: Single centre cohort study SETTING: National tertiary referral center Patients: One hundred fourteen patients with surgically repaired tetralogy of Fallot with median age 29.5 years (range 17.5-64.2). Prospective follow-up for mean 2.4 years (SD 1.29). INTERVENTIONS: Cardiovascular magnetic resonance was performed, and late gadolinium enhancement mass was estimated for the LV using the 5-SD remote myocardium method, and for the RV using a segmental scoring system. Cohort characterization was determined through the use of a computerized database. OUTCOME MEASURES: Survival analysis from time of scan to first adverse event, defined as an episode of atrial arrhythmia, sustained ventricular arrhythmia, hospitalization with heart failure, or implantable cardioverter-defibrillator insertion. RESULTS: Eleven patients experienced an adverse outcome in the follow-up period, although there were no deaths. LV late gadolinium enhancement was associated with adverse outcomes in a univariate model (P = .027). However, when adjusted for age at scan the significant variables included NYHA class (P = .006), peak oxygen uptake (P = .028), number of prior sternotomies (P = .044), and higher indexed RV and LV end diastolic volumes (P = .002 and P < .001), but not RV or LV late gadolinium enhancement. CONCLUSIONS: Formal quantification of late gadolinium enhancement is not currently as helpful in ascertaining prognosis compared to other, more easily assessed parameters in a contemporary cohort of tetralogy of Fallot survivors, however assessment particularly of the LV holds promise for the future.

Larger Centers Produce Better Outcomes in Pediatric Cardiac Surgery: Regionalization is a Superior Model - The Con Prospective.

Regionalization, in the context of congenital heart surgery, describes a process where smaller units close and patients are redistributed to larger centers. Proponents argue this will produce superior patient outcome based primarily on a volume-outcome effect. The potential disadvantage is that, as distance to center increases, access to service is compromised. In this article the volume-outcome effect is appraised and the effect of risk-stratification and threshold volumes explored. Access to service, and how certain congenital lesions and demographics might be disadvantaged, is reviewed. Alternative models are considered including collaborative programing and a standardizing approach of agreed parameters in personnel and infrastructure. Finally the influence of newer developments and quality metrics, including outcome databases, digital technologies and team-cognitive performance, needs to be factored in as the future unfolds. Ultimately, the design of a national congenital cardiac program should aspire to deliver care that is optimal, equitable and economic for the whole population. The solution lies in the distillation of competing variables cognizant of regional demographics and geography.

Two-Strip Technique to Repair Common Atrioventricular Valve Regurgitation in Single-Ventricle Palliation.

A common atrioventricular valve (CAVV) presents a challenge in single-ventricle palliation (SVP) because of its propensity to leak, with CAVV regurgitation being an important risk factor for repeated operation and mortality. We propose a new technique of CAVV repair in the context of SVP. The method uses the techniques of complete repair of antrioventricular septal defect while maintaining free communication at atrial and ventricular levels necessary for single-ventricle physiology.