RESUMEN
The abnormal hemodynamics in Fontan circulation due to persistently increased systemic venous pressure results in hepatic venous congestion and Fontan-associated liver disease. Combined assessment of cardiac and liver fibrosis and cardiac remodeling using multiparametric MRI in this context have not been fully explored. To evaluate cardiac and liver fibrosis and cardiac remodeling using multiparametric MRI in patients who have undergone Fontan procedures. Thirty-eight patients and 23 controls underwent cardiac and liver MRI examinations in a 3.0-T scanner. Mann-Whitney, Fisher exact test, and Spearman's correlation were applied to evaluate myocardial volumes, function, native cardiac and liver T1 mapping, ECVs and liver stiffness. The mean native cardiac T1 value (p = 0.018), cardiac ECV (p < 0.001), liver native T1 (p < 0.001), liver ECV (p < 0.001), and liver stiffness (p < 0.001) were higher in patients than controls. The indexed end-diastolic volume (EDVi) correlated with the myocardial ECV (r = 0.356; p = 0.033), native liver T1 (r = 0.571; p < 0.001), and with liver stiffness (r = 0.391; p = 0.015). In addition, liver stiffness correlated with liver ECV (r = 0.361; p = 0.031) and native liver T1 (r = 0.458; p = 0.004). An association between cardiac remodeling and cardiac and liver fibrosis were found in this population. The usefulness of MRI to follow cardiac and liver involvement in these patients is critical to improve treatment strategies and to prevent the need for combined liver and heart transplantation.
RESUMEN
The present work is concerned with the use of a Response Surface Model of the reduced flexibility matrix for structural damage identification. A Response Surface Model (RSM) is fitted with the aim at providing a polynomial relationship between nodal cohesion parameters, used to describe the damage field within the structure, and elements of the reduced flexibility matrix. A design of experiment built on combinations of a relatively small number of nodal cohesion parameters is used to fit the RSM. The damage identification problem is formulated within the Bayesian framework and the Delayed Rejection Adaptive Metropolis method is used to sample the posterior probability density function of the uncertain cohesion parameters. Numerical simulations addressing damage identification in plates were carried out in order to assess the proposed approach, which succeeded in the identification of the different damage profiles considered. Besides, the use of a RSM, instead of a FEM of the structure, resulted in reductions of up almost 78% in the required computational cost.
Asunto(s)
Teorema de Bayes , Simulación por Computador , Modelos TeóricosRESUMEN
Anomalous coronary arteries arising from the pulmonary trunk is a rare but potentially fatal condition. We report the clinical presentation, surgical treatment and long-term follow-up of seven surgical cases of anomalous left coronary and one case of anomalous right coronary artery arising from the pulmonary artery. Age ranged from 7 months to 13 years (average: 5.09+/-3.7 years) and weight ranged from 7 to 50 kg (average: 19.9+/-8.8 kg). Follow-up was 100% complete: average 78 months (S.D.: 52.7 months). Direct reimplantation was the surgical technique in six cases, Takeuchi procedure in one case and subclavian artery interposition in one case. Concomitant mitral valve repair was undertaken in two cases. In two children the coronary artery anomaly was diagnosed and treated only after a first surgery for other congenital heart anomaly. Left ventricle ejection fraction was restored in those cases of pre-operative dysfunction. Mortality was not observed and all children are asymtomatic and free of reoperation.
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Procedimientos Quirúrgicos Cardíacos , Anomalías de los Vasos Coronarios/cirugía , Arteria Pulmonar/cirugía , Adolescente , Implantación de Prótesis Vascular , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Niño , Preescolar , Anomalías de los Vasos Coronarios/fisiopatología , Femenino , Humanos , Lactante , Masculino , Arteria Pulmonar/anomalías , Reimplantación , Volumen Sistólico , Arteria Subclavia/cirugía , Factores de Tiempo , Resultado del Tratamiento , Función Ventricular IzquierdaRESUMEN
OBJECTIVES: Our aim is to describe our surgical approach in dealing with patients having atrioventricular septal defect with common atrioventricular junction and ventricular shunting associated with tetralogy of Fallot over the last 8 years, and to present our results in mid-to-long term follow-up. METHODS: Between November 1995 and January 2004, we performed surgical correction in 8 consecutive children with atrioventricular septal defect, common atrioventricular junction, interventricular shunting, and associated tetralogy of Fallot. The age at surgical correction varied from 8 months to 20 years, with a mean of 45 months, and standard deviation of 74 months. A palliative systemic-to-pulmonary shunt had previously been performed in 3 patients. Follow-up ranged from 57 to 135 months, with a mean of 93.5 months, and standard deviation of 32 months. We used a two-patch technique to repair of the atrioventricular septal defect, and a pericardial transjunctional patch for relief of the obstruction in the right ventricular outflow tract. RESULTS: There were no deaths, nor reoperations either in the postoperative period or during follow-up. All patients are asymptomatic, or in the second class created by the New York Heart Association. The mean period of cardiopulmonary by-pass was 136 minutes, and the mean stay in hospital was 11.8 days. At the last examination, pulmonary valvar insufficiency was considered severe in 2 patients, and moderate in another 2. No patient developed more than a trace of regurgitation across the reconstituted left atrioventricular valve. CONCLUSIONS: The two-patch technique, associated with ventriculotomy and a transjunctional pulmonary patch is safe and efficient when correcting atrioventricular septal defect associated with tetralogy of Fallot, resulting in good mid-to-long term clinical outcomes.
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Procedimientos Quirúrgicos Cardíacos/métodos , Defectos del Tabique Interatrial/cirugía , Defectos del Tabique Interventricular/cirugía , Tetralogía de Fallot/cirugía , Adolescente , Adulto , Niño , Preescolar , Ecocardiografía Doppler , Estudios de Seguimiento , Defectos del Tabique Interatrial/diagnóstico por imagen , Defectos del Tabique Interatrial/fisiopatología , Defectos del Tabique Interventricular/diagnóstico por imagen , Defectos del Tabique Interventricular/fisiopatología , Humanos , Lactante , Periodo Posoperatorio , Reoperación , Estudios Retrospectivos , Tetralogía de Fallot/diagnóstico por imagen , Tetralogía de Fallot/fisiopatología , Factores de Tiempo , Resultado del Tratamiento , Función Ventricular/fisiologíaRESUMEN
We report our results on surgical treatment of complete atrioventricular septal defects using the two-patch technique. Forty patients with complete atrioventricular septal defects were operated on in the period from November 1995 to January 2004 and retrospectively analyzed. The age at the time of surgery ranged from 4 months to 20 years (average=18.8+/-37 months). Their weights ranged from 3 to 39 kg (average=7.6+/-5.8 kg). Associated tetralogy of Fallot was present in 20% of the cases (8 patients). Monitoring was complete until January 2007, corresponding to a follow-up ranging from 36 to 135 months (average=74+/-33.7 months). The surgical mortality rate was 2.5% and the hospital mortality rate was 5%. A third patient died from a brain abscess two years after surgery. Over the long-term, two patients needed further operations: one was submitted to mitral plasty due to severe residual mitral insufficiency, one year later; the other underwent a resection of a sub-aortic membrane after three years. Differences were evaluated using the Student-t or Mann-Whitney tests. Surgical treatment of complete atrioventricular septal defect using the two-patch technique results in low morbidity and mortality in early-to-mid term follow-up.