Eleven Years After Scimitar Syndrome Repair With the Lugones Technique: Usefulness of Four-Dimensional Flow Magnetic Resonance Imaging.

Anatomic and physiologic assessment of surgical repair of scimitar syndrome can be challenging. We evaluated the first patient who underwent the Lugones procedure in 2012 using 4D flow magnetic resonance imaging. With this technology, we demonstrate that the reconstructed right pulmonary venous return drains into the left atrium with laminar flow, just as normal pulmonary veins do.

Living to Tell the Tale: A First-Person Chronicle of the Development of the Fontan-Kreutzer Procedure.

The current surgical approach for patients with a single ventricle is the culmination of decades of dedicated research and groundbreaking innovation. From 1971 to the present day, a series of incremental advancements have significantly extended the life expectancy of these patients. Since the very beginning, Dr Guillermo Kreutzer and his team have pioneered different techniques with the ultimate goal of improving outcomes for these individuals. This is, narrated by him, the story of how it all began.

Electronic computer-based model of combined ventilation using a new medical device / Modelo electrónico basado en computadora de ventilación combinada utilizando un nuevo dispositivo médico

INTRODUCTION: The increased demand for mechanical ventilation caused by the COVID-19 pandemic could generate a critical situation where patients may lose access to mechanical ventilators. Combined ventilation, in which two patients are ventilated simultaneously but independently with a single ventilator has been proposed as a life-saving bridge while waiting for new ventilators availability. New devices have emerged to facilitate this task and allow individualization of ventilatory parameters in combined ventilation. In this work we run computer-based electrical simulations of combined ventilation. We introduce an electrical model of a proposed mechanical device which is designed to individualize ventilatory parameters, and tested it under different circumstances. MATERIALS AND METHODS: With an electronic circuit simulator applet, an electrical model of combined ventilation is created using resistor-capacitor circuits. A device is added to the electrical model which is capable of individualizing the ventilatory parameters of two patients connected to the same ventilator. Through computational simulation, the model is tested in different scenarios with the aim of achieving adequate ventilation of two subjects under different circumstances: 1) two identical subjects; 2) two subjects with the same size but different lung compliance; and 3) two subjects with different sizes and compliances. The goal is to achieve the established charge per unit of size on each capacitor under different levels of end-expiratory voltage (as an end-expiratory pressure analog). Data collected included capacitor charge, voltage, and charge normalized to the weight of the simulated patient. RESULTS: Simulations show that it is possible to provide the proper charge to each capacitor under different circumstances using an array of electrical components as equivalents to a proposed mechanical device for combined ventilation. If the pair of connected capacitors have different capacitances, adjustments must be made to the source voltage and/or the resistance of the device to provide the appropriate charge for each capacitor under initial conditions. In pressure control simulation, increasing the end-expiratory voltage on one capacitor requires increasing the source voltage and the device resistance associated with the other simulated patient. On the other hand, in the volume control simulation, it is only required to intervene in the device resistance. CONCLUSIONS: Under simulated conditions, this electrical model allows individualization of combined mechanical ventilation.

INTRODUCCIÓN: La mayor demanda de ventilación mecánica provocada por la pandemia de COVID-19 podría generar una situación crítica en la que los pacientes podrían perder el acceso a ventiladores mecánicos. La ventilación combinada, en la que dos pacientes son ventilados simultáneamente, pero de forma independiente con un solo ventilador se ha propuesto como un puente para salvar vidas mientras se espera la disponibilidad de nuevos ventiladores. Han surgido nuevos dispositivos para facilitar esta tarea y permitir la individualización de los parámetros ventilatorios en la ventilación combinada. En este trabajo realizamos simulaciones eléctricas por computadora de ventilación combinada. Presentamos un modelo eléctrico de un dispositivo mecánico propuesto que está diseñado para individualizar los parámetros ventilatorios y lo probamos en diferentes circunstancias. MÉTODOS: Con un programa simulador de circuitos electrónicos, se creó un modelo eléctrico de ventilación combinada utilizando circuitos resistor-capacitor. Se añadió al modelo eléctrico un dispositivo que es capaz de individualizar los parámetros ventilatorios de dos pacientes conectados a un mismo ventilador. Mediante simulación computacional, el modelo se prueba en diferentes escenarios con el objetivo de lograr una ventilación adecuada de dos sujetos en diferentes circunstancias: 1) dos sujetos idénticos; 2) dos sujetos con el mismo tamaño, pero diferente distensibilidad pulmonar; y 3) dos sujetos con diferentes tamaños y distensibilidad. El objetivo es lograr la carga establecida por unidad de tamaño en cada capacitor bajo diferentes niveles de voltaje al final de la espiración (como un análogo a la presión al final de la espiración). Los datos recopilados incluyeron la carga del capacitor, el voltaje y la carga normalizada al peso del paciente simulado. RESULTADOS: Las simulaciones muestran que es posible proporcionar la carga adecuada a cada capacitor en diferentes circunstancias utilizando una matriz de componentes eléctricos como equivalente a al dispositivo mecánico propuesto para la ventilación combinada. Si el par de capacitores conectados tienen diferentes capacitancias, se deben realizar ajustes en el voltaje de la fuente y/o la resistencia del dispositivo para proporcionar la carga adecuada para cada capacitor. En la simulación de presión control, aumentar el voltaje al final de la espiración en un capacitor requiere aumentar el voltaje de la fuente y la resistencia del dispositivo asociado con el otro paciente simulado. Por otro lado, en la simulación de volumen control, solo se requiere intervenir en la resistencia del dispositivo. CONCLUSIONES: Bajo las condiciones simuladas, este modelo eléctrico permite la individualización de la ventilación mecánica combinada.

A Hybrid Strategy for Geometrical Reshaping of the Main Pulmonary Artery and Transcatheter Pulmonary Valve Replacement.

Transcatheter pulmonary valve replacement has become an attractive alternative to surgical approach in patients with dysfunctional right ventricular outflow tract. However, in certain cases, an unfavorable anatomy might complicate optimal valve deployment and stability. Several techniques have been described to reshape the landing zone and allow proper implantation of the transcatheter valve. Among them, the hybrid approach has gained attention as an interesting method for off-pump pulmonary valve replacement in patients with dilated right ventricular outflow tract. But to date, there is no standardized method to resize and reshape the landing zone for the stented valve. Here, we describe a reproducible method based on simple geometric rules to allow adequate remodeling of the main pulmonary artery to the desired dimensions in a single attempt, followed by perventricular implantation of a Venus P-valve.

Combined Ventilation of Two Subjects with a Single Mechanical Ventilator Using a New Medical Device: An In Vitro Study.

INTRODUCTION: The SARS-CoV-2 pandemic has created a sudden lack of ventilators. DuplicARⓇ is a novel device that allows simultaneous and independent ventilation of two subjects with a single ventilator. The aims of this study are (a) to determine the efficacy of DuplicARⓇ to independently regulate the peak and positive-end expiratory pressures in each subject, both under pressure-controlled ventilation and volume-controlled ventilation and (b) to determine the ventilation mode in which DuplicARⓇ presents the best performance and safety. MATERIALS AND METHODS: Two test lungs are connected to a single ventilator using DuplicARⓇ. Three experimental stages are established: (1) two identical subjects, (2) two subjects with the same weight but different lung compliance, and (3) two subjects with different weights and lung compliances. In each stage, the test lungs are ventilated in two ventilation modes. The positive-end expiratory pressure requirements are increased successively in one of the subjects. The goal is to achieve a tidal volume of 7 ml/kg for each subject in all different stages through manipulation of the ventilator and the DuplicARⓇ controllers. RESULTS: DuplicARⓇ allows adequate ventilation of two subjects with different weights and/or lung compliances and/or PEEP requirements. This is achieved by adjusting the total tidal volume for both subjects (in volume-controlled ventilation) or the highest peak pressure needed (in pressure-controlled ventilation) along with the basal positive-end expiratory pressure on the ventilator and simultaneously manipulating the DuplicARⓇ controllers to decrease the tidal volume or the peak pressure in the subject that needs less and/or to increase the positive-end expiratory pressure in the subject that needs more. While ventilatory goals can be achieved in any of the ventilation modes, DuplicARⓇ performs better in pressure-controlled ventilation, as changes experienced in the variables of one subject do not modify the other one. CONCLUSIONS: DuplicARⓇ is an effective tool to manage the peak inspiratory pressure and the positive-end expiratory pressure independently in two subjects connected to a single ventilator. The driving pressure can be adjusted to meet the requirements of subjects with different weights and lung compliances. Pressure-controlled ventilation has advantages over volume-controlled ventilation and is therefore the recommended ventilation mode.

The Kawashima Operation With Simultaneous Preparation for Transcatheter Fontan-Kreutzer Completion.

Patients with functionally single ventricle and interrupted inferior vena cava may develop progressive cyanosis soon after the Kawashima operation. Therefore, early redirection of the hepatic venous return to the pulmonary circulation is recommended. To avoid performing an early redo sternotomy, we propose to prepare these patients for the interventional Fontan-Kreutzer at the time of the Kawashima operation using a technical modification of the approach reported by Prabhu and coworkers in 2017. The technique described here uses an expanded polytetrafluoroethylene conduit interposed between the hepatic veins and the right pulmonary artery. This graft is everted and divided into two portions with a pericardial patch. The lower one is widely opened and anastomosed side-to-side to the atrium. A few months after the operation, percutaneous Fontan-Kreutzer completion can easily be performed using covered stents to open the patch and at the same time close the opening between the conduit and the atrium.

A New Medical Device to Provide Independent Ventilation to Two Subjects Using a Single Ventilator: Evaluation in Lung-Healthy Pigs.

BACKGROUND: The global crisis situation caused by SARS-CoV-2 has created an explosive demand for ventilators, which cannot be met even in developed countries. Designing a simple and inexpensive device with the ability to increase the number of patients that can be connected to existing ventilators would have a major impact on the number of lives that could be saved. We conducted a study to determine whether two pigs with significant differences in size and weight could be ventilated simultaneously using a single ventilator connected to a new medical device called DuplicARⓇ. METHODS: Six pigs (median weight 12 kg, range 9-25 kg) were connected in pairs to a single ventilator using the new device for 6 hours. Both the ventilator and the device were manipulated throughout the experiment according to the needs of each animal. Tidal volume and positive end-expiratory pressure were individually controlled with the device. Primary and secondary outcome variables were defined to assess ventilation and hemodynamics in all animals throughout the experiment. RESULTS: Median difference in weight between the animals of each pair was 67% (range: 11-108). All animals could be successfully oxygenated and ventilated for 6 hours through manipulation of the ventilator and the DuplicARⓇ device, despite significant discrepancies in body size and weight. Mean PaCO2 in arterial blood was 42.1 ± 4.4 mmHg, mean PaO2 was 162.8 ± 46.8 mmHg, and mean oxygen saturation was 98 ± 1.3%. End-tidal CO2 values showed no statistically significant difference among subjects of each pair. Mean difference in arterial PaCO2 measured at the same time in both animals of each pair was 4.8 ± 3 mmHg, reflecting the ability of the device to ventilate each animal according to its particular requirements. Independent management of PEEP was achieved by manipulation of the device controllers. CONCLUSION: It is possible to ventilate two lung-healthy animals with a single ventilator according to each one's needs through manipulation of both the ventilator and the DuplicARⓇ device. This gives this device the potential to expand local ventilators surge capacity during disasters or pandemics until emergency supplies can be delivered from central stockpiles.

The matter of "unbalance" in right dominant atrioventricular septal defect.

Unbalance in atrioventricular septal defect can be found in more than one anatomic level and in different degrees at each level. The definition of "unbalance" has historically been focused in comparing the dimensions of main cardiac structures, such as the atrioventricular valve and the ventricles. However, the hemodynamic aspects of unbalance need to be considered as having, at least, similar relevance. New concepts and already described parameters must be combined and understood as a whole to help the surgical decision-making process.

Modified In Situ Pericardial Rerouting Technique for Scimitar Syndrome Repair.

Scimitar syndrome repair represents a challenge due to the high incidence of postoperative pulmonary venous obstruction associated with classic surgical strategies. In situ pericardial rerouting technique has been considered a promising alternative approach due to its simplicity and excellent midterm results. Access to the left atrium can be difficult in young patients with severe dextrocardia and hypoplastic right lung. We describe a modification of the original rerouting technique in which the atrial septum is repositioned in order to create a wide opening in the lateral aspect of the left atrium and ensure an adequate size of the reconstructed pathway.

Feasibility of Biventricular Repair in Right Dominant Unbalanced Atrioventricular Septal Defect: A New Echocardiographic Metric to Refine Surgical Decision-Making.

BACKGROUND: Unbalanced forms of atrioventricular septal defect continue to be challenging and present poor surgical outcomes. Echocardiographic indicators such as atrioventricular valve index, right ventricle/left ventricle inflow angle, and size of the ventricular septal defect have been identified as relevant discriminators that may guide surgical strategy. Our purpose is to describe another metric to refine surgical decision-making. METHODS: We outline a geometrical description of the anatomic features of atrioventricular septal defect and describe equations that help explain the interplay between the main echocardiographic variables. RESULTS: A new metric called "indexed ventricular septal defect" is defined as the size of the defect in relation to the valve diameter. We derive a final equation relating this index with the atrioventricular valve index and the right ventricle/left ventricle inflow angle. In the light of that equation, we discuss the interdependence of variables and employ data from a Congenital Heart Surgeons' Society study to set the limits of the new index. CONCLUSION: Combined use of indexed ventricular septal defect and atrioventricular valve index might help clarify surgical decision-making in patients with mild and moderate unbalance (modified atrioventricular valve index between 0.2 and 0.39). For indexed ventricular septal defect smaller than 0.2, biventricular repair may be recommended. Between 0.2 and 0.35, this strategy could probably be achieved depending on other factors. However, other strategies should be considered for those patients showing an indexed ventricular septal defect between 0.35 and 0.5. For values above 0.5 to 0.55, univentricular palliation might be a reasonable strategy.

Unique combination of atrioventricular septal defect with cor triatriatum and complete vascular ring.

Atrioventricular septal defect can present with one or more associated anomalies. Cor triatriatum (subdivided left atrium) and vascular rings are among the less frequent. We describe a two-month-old patient with these three cardiovascular anomalies. This case highlights the importance of exhaustive preoperative evaluation in order to achieve successful surgical correction in one stage.

Origen anómalo de la coronaria izquierda en la arteria pulmonar: resultados de la cirugía correctora / Outcomes after Surgical Correction of Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery

Introducción El origen anómalo de la arteria coronaria izquierda en la arteria pulmonar es una cardiopatía congénita rara que produce isquemia miocárdica con disfunción ventricular izquierda e insuficiencia mitral de grado variable. Las técnicas actuales han modificado la historia natural de esta enfermedad mediante el restablecimiento de un sistema de doble irrigación coronaria. Objetivos Evaluar la experiencia institucional en la corrección quirúrgica del origen anómalo de la coronaria izquierda en la arteria pulmonar. Material y métodos Entre febrero de 2000 y mayo de 2008 fueron operados 13 pacientes con este diagnóstico. Seis eran menores de 1 año; mediana: 2,5 años; rango: 45 días a 21 años. Antes de la cirugía, el 61% de los pacientes presentaban insuficiencia cardíaca, el 69% signos de infarto y el 84% cardiomegalia moderada a grave. La fracción de acortamiento promedio era del 26,07% y existía insuficiencia mitral moderada a grave en el 46% de los casos. El diagnóstico se confirmó por cateterismo en 11 pacientes. En un paciente se realizó cirugía de Takeuchi y en los 12 restantes se efectuó el reimplante de la coronaria izquierda en la aorta. En un paciente se realizó plástica mitral. Seis recibieron perfusión y cardioplejía de la coronaria anómala por la arteria pulmonar. Resultados La mortalidad al presente, con un seguimiento promedio de 74,76 meses, es del 0%. Ningún paciente presentaba insuficiencia cardíaca al alta. En 9 de los 11 pacientes con cardiomegalia, ésta se redujo. La fracción de acortamiento promedio posoperatoria fue del 39,92%. La insuficiencia mitral disminuyó en todos los que la presentaban, excepto en uno. Ninguno presentó insuficiencia grave en el posoperatorio alejado. Conclusiones Los resultados de la cirugía correctora del origen anómalo de la coronaria izquierda en la arteria pulmonar son excelentes en todos los grupos etarios, con mejoría significativa de la función miocárdica y disminución de la insuficiencia mitral en la mayoría de los pacientes.

Background The anomalous origin of the left coronary artery from the pulmonary artery is a rare congenital heart defect that produces myocardial ischemia with left ventricular dysfunction and mitral regurgitation. The natural history of the disease has been modified by the current surgical techniques which establish a system with two coronary arteries. Objectives To evaluate our experience with the surgical correction of the anomalous origin of the left coronary artery from the pulmonary artery. Material and Methods A total of 13 patients underwent surgical repair of this condition from February 2000 to May 2008. Median age was 2.5 years; range 45 days to 21 years. Six patients were <1 year old. Before surgery, 61% of patients presented congestive heart failure, 69% had signs of myocardial infarction and 84% moderate to severe heart enlargement. Average shortening fraction was 26.07% and 46% of patients had moderate to severe mitral regurgitation. The diagnosis was confirmed by coronary angiography in 11 patients. The Takeuchi procedure was performed in one patient and 12 patients underwent direct anastomosis of the anomalous left coronary artery directly to the aorta. One patient underwent mitral valve repair. Perfusion of the anomalous coronary artery and cardioplegia were provided via the pulmonary artery in six patients. Results At present, after a mean follow-up of 74.76 months, mortality rate is 0%. None of the patients presented congestive heart failure at discharge. A reduction in cardiac size was observed in 9/11 patients. The average postoperative shortening fraction was 39.92%. A decrease in the severity of mitral regurgitation was observed in all patients with only one exception. None of the patients presented severe mitral regurgitation in the late postoperative period. Conclusions The outcomes of the surgical correction of the anomalous origin of the left main coronary artery from the pulmonary artery are excellent in all age groups, with significant improvement of myocardial function and reduction of the severity of mitral regurgitation in most patients.

Aortopulmonary fistula after an arterial switch operation.

Aortopulmonary fistula has been documented in adult patients with acute aortic dissection, atherosclerotic disease, and other comorbidities. However, until now we believe this was not previously reported as a complication after the arterial switch operation in a patient with transposition of the great arteries. We report the case of a 3-month-old boy who underwent an arterial switch operation as a neonate. After balloon dilation to relieve a postoperative supravalvular pulmonary stenosis, he presented with severe congestive heart failure due to an undiagnosed but previously present fistula between the ascending aorta and the main pulmonary artery. He underwent successful surgical repair and recovered uneventfully.

Acrocomia aculeata as an unreported cause of tricuspid regurgitation.

Penetrating chest trauma can produce a wide range of lesions to cardiac structures. Some patients develop signs and symptoms of residual sequelae. We describe the case of an 11-year-old boy with severe tricuspid regurgitation caused by the thorn of a palm tree. A De Vega annuloplasty of the tricuspid valve and a bidirectional Glenn procedure were successfully performed 7 years after the episode. This case illustrates the importance of a thorough investigation of possible valvular heart disease in patients who suffered from chest trauma.