Assessing the methodology used to study the ascending aorta haemodynamics in bicuspid aortic valve.

Aims: Modern imaging techniques provide evermore-detailed anatomical and physiological information for use in computational fluid dynamics to predict the behaviour of physiological phenomena. Computer modelling can help plan suitable interventions. Our group used magnetic resonance imaging and computational fluid dynamics to study the haemodynamic variables in the ascending aorta in patients with bicuspid aortic valve before and after isolated tissue aortic valve replacement. Computer modelling requires turning a physiological model into a mathematical one, solvable by equations that undergo multiple iterations in four dimensions. Creating these models involves several steps with manual inputs, making the process prone to errors and limiting its inter- and intra-operator reproducibility. Despite these challenges, we created computational models for each patient to study ascending aorta blood flow before and after surgery. Methods and results: Magnetic resonance imaging provided the anatomical and velocity data required for the blood flow simulation. Patient-specific in- and outflow boundary conditions were used for the computational fluid dynamics analysis. Haemodynamic variables pertaining to blood flow pattern and derived from the magnetic resonance imaging data were calculated. However, we encountered problems in our multi-step methodology, most notably processing the flow data. This meant that other variables requiring computation with computational fluid dynamics could not be calculated. Conclusion: Creating a model for computational fluid dynamics analysis is as complex as the physiology under scrutiny. We discuss some of the difficulties associated with creating such models, along with suggestions for improvements in order to yield reliable and beneficial results.

Optimal B-spline Mapping of Flow Imaging Data for Imposing Patient-specific Velocity Profiles in Computational Hemodynamics.

OBJECTIVE: We propose a novel method to map patient-specific blood velocity profiles obtained from imaging data such as 2D flow MRI or 3D colour Doppler ultrasound) to geometric vascular models suitable to perform CFD simulations of haemodynamics. We describe the implementation and utilisation of the method within an open-source computational hemodynamics simulation software (CRIMSON). METHODS: The proposed method establishes point-wise correspondences between the contour of a fixed geometric model and time-varying contours containing the velocity image data, from which a continuous, smooth and cyclic deformation field is calculated. Our methodology is validated using synthetic data, and demonstrated using two different in-vivo aortic velocity datasets: a healthy subject with normal tricuspid valve and a patient with bicuspid aortic valve. RESULTS: We compare our method with the state-of-the-art Schwarz-Christoffel method, in terms of preservation of velocities and execution time. Our method is as accurate as the Schwarz-Christoffel method, while being over 8 times faster. CONCLUSIONS: Our mapping method can accurately preserve either the flow rate or the velocity field through the surface, and can cope with inconsistencies in motion and contour shape. SIGNIFICANCE: The proposed method and its integration into the CRIMSON software enable a streamlined approach towards incorporating more patient-specific data in blood flow simulations.

Patterns of compliance with prenatal iron supplementation among Peruvian women.

Prenatal iron supplementation is recommended to control anaemia during pregnancy. Low compliance and side effects have been claimed as the main obstacles for adequate impact of the supplementation. As part of a double-blind supplementation study carried out in a hospital located in a shantytown in Lima, Peru, we monitored compliance throughout pregnancy and evaluated factors associated with variation in compliance over time. Overall, 985 pregnant women were enrolled in a supplementation study that was administered through their prenatal care from 10 to 24 weeks of gestation until 4 weeks postpartum. They received 60 mg iron and 250 µg folate with or without 15 mg zinc. Women had monthly care visits and were also visited weekly to query regarding compliance, overall health status, and potential positive and negative effects of supplement consumption. Median compliance was 79% (inter-quartile range: 65-89%) over pregnancy, and the median number of tablets consumed was 106 (81-133). Primpara had lower average compliance; positive health reports were associated with greater compliance, and negative reports were associated with lower compliance. There was no difference by type of supplement. Women with low initial compliance did achieve high compliance by the end of pregnancy, and women who reported forgetting to take the supplements did have lower compliance. Compliance was positively associated with haemoglobin concentration at the end of pregnancy. In conclusion, women comply highly with prenatal supplementation within a prenatal care model in which supplies are maintained and reinforcing messages are provided.

Randomized controlled trial of prenatal zinc supplementation and the development of fetal heart rate.

OBJECTIVES: This study was undertaken to evaluate whether prenatal zinc supplementation affects maturation of fetal cardiac patterns. STUDY DESIGN: A randomized double-blind controlled trial among 242 low-income Peruvian women was performed. Beginning at 10 to 16 weeks' gestation, women received supplements containing 60 mg iron, 250 microg folic acid with or without 25 mg zinc. Fetal heart rate (mean FHR, variability [HRV], number of accelerations) and movements (number and amplitude of movement bouts, time spent moving) were electronically monitored monthly from 20 weeks' gestation. Developmental trends were evaluated by supplement type among 195 women who completed the trial and had no serious complications of pregnancy. RESULTS: Zinc supplementation was associated with lower FHR, greater number of accelerations, and greater HRV. Supplementation effects on HRV and accelerations were more pronounced after 28 weeks' gestation. No differences in motor activity were observed. CONCLUSION: Prenatal supplementation of zinc-deficient mothers may be beneficial to fetal neurobehavioral development.

Randomized controlled trial of prenatal zinc supplementation and fetal bone growth.

BACKGROUND: Maternal zinc deficiency is relatively common in developing countries, but its consequences for fetal growth are not established. OBJECTIVE: The goal was to examine whether improvement in maternal gestational zinc status is positively associated with fetal growth as assessed by ultrasonography. DESIGN: We conducted a double-masked, randomized trial among 242 pregnant Peruvian women in an impoverished shantytown in Lima, Peru. At 10-16 wk of gestation, the women were randomly assigned to receive daily supplements containing 60 mg Fe and 250 microg folic acid, with or without 25 mg Zn. We measured fetal head circumference, biparietal diameter, abdominal circumference, and femur diaphysis length at 20, 24, 28, 32, 36, and 38 wk of gestation. Fetal measures were analyzed longitudinally to evaluate differences in trends of fetal growth by supplement type, and within-subject correlations were taken into account. RESULTS: Femur diaphysis length was greater in fetuses whose mothers received zinc supplements (P < 0.05), and the difference tended to increase with gestational age. No significant differences by supplement type were observed for the other anatomical sites measured. CONCLUSIONS: The observed positive effect of prenatal zinc on fetal femur diaphysis length is consistent with the results of experimental studies in animals and in vitro. The supplementation effect represents an upward shift in mean femur diaphysis length at term of about one-quarter of the reference SD. These findings suggest the potential importance of maternal zinc status for fetal bone growth in humans and illustrate the value of ultrasonography for evaluating the effect of prenatal nutritional interventions on components of fetal growth.

Aneurisma de la aorta ascendente: resultados quirúrgicos / Abeurysm of the ascending aorta: surgical results

Con el presente trabajo, nos proponemos caracterizar a los pacientes con aneurisma de aorta ascente operados en nuestro hospital , así como analizar las técnicas quirúrgicas empleadas en éstos. Asimismo comparamos nuestros resultados con los obtenidos por otros autores. Se revisaron las historias clínicas de los 17 pacientes operados en el Servicio de Cirugía Cardiovascular del Hospital Clinioquirúrgico "Hermanos Ameijeiros" por presentar aneurisma de la aorta ascendente, asociado o no con insuficiencia aórtica, en un período comprendido entre septiembre de 1985 y julio de 1992. Se describe el proceder quirúrgico utilizado y se analizan una serie de variables como edad, sexo, manifestaciones clínicas, diagnóstico, técnica quirúrgica empleada y complicaciones. Podemos plantear que el resultado del tratamiento de elección para los aneurismas de la aorta ascendente o disecciones agudas de la misma es el tratamiento quirúrgico, y que el diagnóstico puede ser sospechado o realizado mediante la radiografía de toráx y la ecocardiografía. Asimismo, la manifestación clínica más frecuentemente asociada es la insuficiencia aórtica

Aneurisma de la aorta ascendente. Resultados quirúrgicos / Aneurysm of the ascending aorta. Surgical results

Con el presente trabajo, nos proponemos caracterizar a los pacientes con aneurisma de aorta ascente operados en nuestro hospital , así como analizar las técnicas quirúrgicas empleadas en éstos. Asimismo comparamos nuestros resultados con los obtenidos por otros autores. Se revisaron las historias clínicas de los 17 pacientes operados en el Servicio de Cirugía Cardiovascular del Hospital Clinioquirúrgico "Hermanos Ameijeiros" por presentar aneurisma de la aorta ascendente, asociado o no con insuficiencia aórtica, en un período comprendido entre septiembre de 1985 y julio de 1992. Se describe el proceder quirúrgico utilizado y se analizan una serie de variables como edad, sexo, manifestaciones clínicas, diagnóstico, técnica quirúrgica empleada y complicaciones. Podemos plantear que el resultado del tratamiento de elección para los aneurismas de la aorta ascendente o disecciones agudas de la misma es el tratamiento quirúrgico, y que el diagnóstico puede ser sospechado o realizado mediante la radiografía de toráx y la ecocardiografía. Asimismo, la manifestación clínica más frecuentemente asociada es la insuficiencia aórtica (AU)

Atención médico-psicológica al familiar del donante / Medico-psychologic care to the family of the donors

En el presente trabajo se hace referencia a la atención medico-psicológica a los familiares del donante cadáver y al equipo de asistencia. Se destacan las 3 etapas fundamentales a través de las cuales se desarrolla la actividad en nuestra institución y las experiencias obtenidas en el trabajo conjunto con otros hospitales del país, se muestran las estadísticas nacionales de los donantes multiórganos desde diciembre de 1985 hasta octubre de 1989, recibidos y/o reportados en el Hospital Clinicoquirúrgico "Hermanos Ameijeiras"

Análisis estadístico de la experiencia en Cuba sobre el donante para trasplante cardíaco / Statistical analysis of the experience on donor for heart transplantation in Cuba

En el presente trabajo se realizó una revisión de los posibles donantes para trasplante cardíaco procesados por el Grupo de Trasplante del Hospital Clinicoquirúrgico "Hermanos Ameijeiras" en el periodo comprendido de diciembre 5 de 1985 hasta 31 de 1988 (3 años). Partiendo del sistema computarizado para la cirugía cardiovascular SINOCA (realizada sobre el lenguaje dbase III) se obtuvo una serie de datos estadísticos sobre diferentes características asociadas directamente con el donante procesado para el trasplante de corazón. Se muestran los criterios de selección del donante para trasplante de corazón y los principios de tratamiento del mismo

Computación y trasplante de órganos / Computation and organ transplantations

En el trabajo se describe un sistema de computación elaborado para el caso de los trasplantes de corazón y toda la organización que se ha derivado del mismo como eje funcional fundamental en el proceso de coordinación de trasplantes. Entre las funciones que realiza se encuentran: la creación de un pool de receptores, recepción y almacenamiento del protocolo actualizado de cada uno de los posibles receptores para trasplante y de los posibles donantes avisados a nuestro servicio, optimización de la selección donante-receptor y toda la recepción, emisión y procesamiento de la información desde que el paciente es trasplantado hasta su fallecimiento, se incluye un proceso de seguimiento que coincide con la biopsia endomiocárdica

Valoración de la radiografía simple de tórax en el estudio preoperatorio del cáncer de mama / Valuation of simple thoracic radiography in the preoperative study of cancer of the breast

Durante los meses de enero de 1977 a diciembre de 1981, se estudiaron los pacientes ingresados en el Servicio de Cirugía General del Hospital Docente Clinicoquirúrgico "General Calixto García" que presentaron cáncer de mama. Se analizaron los resultados del estudio radiográfico simple del tórax y se relacionaron con los datos generales y el examen físico del paciente. Se revisó la literatura médica nacional e internacional a nuestro alcance. Se hacen conclusiones y recomendaciones

Valoración de la radiografía simple de tórax en el estudio preoperatorio del cáncer de mama / Valuation of simple thoracic radiography in the preoperative study of cancer of the breast

Durante los meses de enero de 1977 a diciembre de 1981, se estudiaron los pacientes ingresados en el Servicio de Cirugía General del Hospital Docente Clinicoquirúrgico "General Calixto García" que presentaron cáncer de mama. Se analizaron los resultados del estudio radiográfico simple del tórax y se relacionaron con los datos generales y el examen físico del paciente. Se revisó la literatura médica nacional e internacional a nuestro alcance. Se hacen conclusiones y recomendaciones (AU)

Fibrolipoma seudoescrotal: presentación de un caso / Pseudoscrotal fibrolipoma: presentation of a case

Se presenta el caso de una enferma con un fibrolipoma gigante de forma seudoescrotal, la cual fue intervenida quirúrgicamente en el Hospital General Docente "Calixto García". Se destaca algunas de sus características más notables. Se revisa la literatura médica a nuestro alcance

Fibrolipoma seudoescrotal. presentación de un caso / Pseudoscrotal fibrolipoma: presentation of a case

Se presenta el caso de una enferma con un fibrolipoma gigante de forma seudoescrotal, la cual fue intervenida quirúrgicamente en el Hospital General Docente "Calixto García". Se destaca algunas de sus características más notables. Se revisa la literatura médica a nuestro alcance (AU)

Fístula colecistocólica: presentación de 2 casos y revisión de la literatura / Cholecystocolonic fistula: report of 2 cases and review of the literature

Se representan 2 casos de fístulas colecistocólicas en el Hospital "General Calixto García" durante un período de 2 años. Se hace una revisión de la literatura disponible a nuestro alcance