Fluidodinâmica Computacional na Avaliação do Risco Futuro de Aneurismas de Aorta Ascendente / Computational Fluid Dynamics to Assess the Future Risk of Ascending Aortic Aneurysms

Resumo Fundamentos Uma metodologia para identificação de pacientes portadores de aneurisma de aorta ascendente (AAAs) sob alto risco de remodelamento aórtico não está completamente definida. Objetivo Esta pesquisa objetiva caracterizar numericamente o fluxo sanguíneo aórtico, relacionando a distribuição do estresse mecânico resultante com o crescimento de AAAs. Métodos Estudo analítico, observacional, unicêntrico, em que um protocolo de fluidodinâmica computacional (CFD - Computacional Fluid Dynamics) foi aplicado a imagens de angiotomografia computadorizada (ATC) de aorta de pacientes portadores de AAAs. Duas ATC de aorta com pelo menos um ano de intervalo foram obtidas. Dados clínicos dos pacientes foram registrados e, a partir das imagens de ATC, foram gerados modelos tridimensionais. Foram realizados estudos do campo de velocidade e estruturas coerentes (vórtices) com o objetivo de relacioná-los ao crescimento ou não do aneurisma e, posteriormente, compará-los com os dados clínicos dos pacientes. O teste de Kolmogorov-Smirnov foi utilizado para avaliar a normalidade da amostra e o teste não-paramétrico Wilcoxon signed-rank foi aplicado para comparações de dados pareados entre os ângulos aórticos. A significância estatística foi fixada em 5%. Resultados Para o grupo que apresentou crescimento do aneurisma, a incidência do jato na parede aórtica gerou áreas de recirculação posterior ao jato, induzindo à formação de vórtices complexos, ocasionando um incremento na pressão média no endotélio aórtico. O grupo sem crescimento do aneurisma apresentou diminuição na pressão média. Conclusão Este estudo piloto mostrou que a CFD baseada em ATC pode, em um futuro próximo, ser uma ferramenta auxiliar na identificação dos padrões de fluxo associados ao processo de remodelamento de AAAs.

Abstract Background A methodology to identify patients with ascending aortic aneurysm (AsAA) under high risk for aortic growth is not completely defined Objetive This research seeks to numerically characterize the aortic blood flow by relating the resulting mechanical stress distribution with AsAA growth. Methods Analytical, observational, single-center study in which a computational fluid dynamics (CFD) protocol was applied to aortic computed tomography angiogram (CTA) images of patients with AsAA. Two CTA exams taken at a minimum interval of one year were obtained. From the CTA-gathered images, three-dimensional models were built, and clinical data were registered. Study of velocity field and coherent structures (vortices) was performed aiming to relate them to the presence or absence of aneurysm growth, as well as comparing them to the patients' clinical data. The Kolmogorov-Smirnov test was used to evaluate the normality of the distribution, and the non-parametric Wilcoxon signed-rank test, for non-normal distribution, was used to compare the paired data of the aortic angles. Statistical significance was set at 5%. Results The incident jet in the aortic wall generated recirculation areas in the posterior region of the jet, inducing complex vortices formation in the group with aneurysm growth, leading to an average pressure increase in the ascending aortic wall between exams. In the group without aneurysm growth, the average pressure decreased. Conclusion This pilot study showed that CFD based on CTA may in the near future be a tool to help identify flow patterns associated with AsAA remodeling process.

The largest reported giant ascending aortic aneurysm presented with superior vena cava syndrome

Abstract Giant ascending aortic aneurysm is a rare condition. In this paper, we present an uncommon case of giant ascending aortic aneurysm with a maximal diameter of 14 cm in a 77-year-old woman presenting with unusual symptoms. The patient underwent a successful surgery involving ascending aortic replacement, and was discharged without any complication. After discharge, she was followed regularly and no major problem was observed in her control visits. To the best of our knowledge, our case is the largest ascending aortic aneurysm reported to date in the existing literature.

Partial congenital absence of the pericardium: a case report

Abstract The complete or the partial absence of pericardium is a rare congenital malformation for which the patients are commonly asymptomatic and the diagnosis is incidental. The absence of the left side of the pericardium is the most common anomaly that is reported in the literature while the complete absence of pericardium or the absence of the right side of the pericardium are uncommon and their criteria are still unrecognized given their rare occurrence in clinical practice. This paper aims to report a case of 19-year-old male with the congenital partial absence of both sides of the pericardium and to highlight the symptoms and the different cardiac imaging modalities used to confirm the diagnosis of this defect.

Efficacy and safety of "coronary artery bypass graft angiography" with right transradial access versus left transradial access and femoral access: a retrospective comparative study

Abstract Objective: Over the past 10 years, the rate of patients who have undergone coronary artery bypass graft (CABG) surgery has increased twofold in cases of coronary angiography. Today, transradial access is the first choice for coronary angiography. We aimed to compare the efficacy and reliability of radial versus femoral access for coronary angiography in post-CABG surgery in this study. Methods: Data from 442 patients who underwent post-CABG surgery between 2012-2017 were retrospectively compared. The right radial route was used in 120 cases, the left radial route in 148, and femoral route in 174. These three pathways were compared in terms of procedure time and fluoroscopy time, efficacy, and complication development. Comparisons among the three groups were performed with Bonferroni test for continuous variables and chi-square or Fisher's exact test for nominal variables as a binary. Results: Comparison results indicate that femoral access was better than left radial access and the left radial access was better than right radial access in terms of fluoroscopy time (10.71±1.65, 10.94±1.25, 16.12±5.28 min, P<0.001) and total procedure time (17.28±1.68, 17.68±2.34, 23.04±5.84 min, P<0.001). The left radial pathway was the most effective way of viewing left internal mammary artery (LIMA). No statistically significant differences were found among the three groups in other graft visualizations, all minor complications, total procedure and fluoroscopy time "Except LIMA imaging". Mortality due to processing was not observed in all three groups. Conclusion: The left radial route is preferred over right radial access for post-CABG angiography because the left radial pathway is close to the LIMA and is similar to the femoral pathway. In LIMA graft imaging, right radial access is a reliable route, even though it is not as effective as other pathways. We hope that the right radial pathway will improve with physician experience and innovations.

Surgical repair of complex aortopulmonary window: a case study

Abstract Aortopulmonary septal defect, also known as the aortopulmonary window, is a rare congenital macrovascular malformation. This case involves a 9-year-old boy with aortopulmonary septal defect (type I combined with type IV). Before surgery, milrinone and alprostadil were used to counteract high lung pressure. Surgery was performed under cardiopulmonary bypass, following which the pulmonary pressure decreased. The aorta was cut, and the right pulmonary artery opening was connected with the main pulmonary artery septal defect using polyester patch. An internal tunnel was made, and the deformity correction was completed. The child exhibited normal postoperative recovery with no discomfort. A complex aortopulmonary window is a rare condition that can be treated successfully with appropriate preoperative and surgical management.

Tratamiento quirúrgico de la úlcera penetrante de aorta ascendente: casos clínicos / Penetrating ulcer of the ascending aorta treated surgically: report of two cases

Penetrating aortic ulcer (PAU) is an ulceration of an atherosclerotic plaque which disrupts the aortic internal elastic lamina and that can evolve to an intramural hematoma (IH), aortic dissection or aortic rupture. We report two cases with PAU. A 73 year-old woman with a history of hypertension, presented with acute chest pain of three days of evolution and a hypertensive emergency. An electrocardiogram showed ST-segment elevation and elevated cardiac enzymes. Computed tomography (CT) scans showed an acute ascending aortic mural hematoma secondary to PAU and hemopericardium. Replacement of ascending aorta was performed with a vascular prosthesis with extracorporeal circulation (ECC). PAU and IH were confirmed by histopathology. A 62-year old woman with a history of hypertension, diabetes and chronic obstructive pulmonary disease, consulted for abdominal pain of two days of evolution. A thoracic-abdominal CT scan visualized an uncomplicated PAU and an abdominal aortic aneurysm. Because of abdominal pain and signs of peritoneal irritation, an exploratory laparotomy was performed finding a typhlitis. Resection and ileo-ascendo-anastomosis were performed. A new CT scan showed PAU with high risk of rupture without a clinical acute aortic syndrome. The patient was operated replacing the ascending aorta with a vascular prosthesis using ECC. Three PAU were found. Histopathology confirmed the diagnosis. Both patients evolved without postoperative complications.

Valor de la angiografía coronaria por tomografía computarizadaen el diagnóstico de las anomalías coronarias / Role of coronary computed tomography angiography for the diagnosis of coronary anomalies

Background: Coronary anomalies are rare heart diseases that can cause sudden cardiac death, especially in young individuals. Coronary computed tomography angiography delivers a three-dimensional view of excellent quality with information of the origin, course and anatomic relationships of the anomalous vessel, allowing differentiation between benign and malignant variants, entities that require different management and treatment. Aim: To show that coronary computed tomography angiography is the non-invasive technique of choice for the evaluation of a coronary anomaly due to its high diagnostic accuracy. Material and Methods: Between 2008 and 2014, 368 coronary computed tomography angiographies were carried out. Six (1.6%) patients had a coronary anomaly. Results: The age of these six patients ranged from 38 to 82 years (five were women). The coronary computed tomography angiography was requested due to cardiac symptoms (angina and dyspnea) in two patients, after a selective coronary arteriography to obtain additional information of the coronary anomaly in three patients, and after a cardiorespiratory arrest in one patient. Three patients had an anomaly of the right coronary artery, two patients had an anomaly of the left coronary artery and one patient had absent left main coronary artery. In five patients the coronary anomaly was malignant. Conclusions: Coronary computed tomography angiography is a robust diagnostic method to evaluate patients with suspected coronary anomalies.

Sex-specific parameters of ascending aorta, descending aorta and pulmonary trunk by computed tomographic angiography with impact of age, hypertension, smoking and diabetes / Parámetros específicos de la parte ascendente de la aorta, parte descendente de la aorta y tronco pulmonar analizados mediante angiografía por tomografía computadorizada relacionados con el sexo, impacto de la edad, hipertensión, tabaquismo y diabetes

This study aims at establishing whether transverse diameter (TD) and cross sectional-area (CSA) of the ascending aorta (AA), descending aorta (DA) and pulmonary trunk (PT) measured by computerized tomographic angiography (CTA) altered by sex, age, hypertension, smoking and diabetes. CTA examinations of the TD and CSA of the AA, DA and PT of 100 patients aged 49.5±16.9 years (range 16­78 years) selected between January 2009 to May 2011 from those referred to Radiology Department, Jordan University Hospital, Faculty of Medicine, University of Jordan, Amman, Jordan for advanced evaluation. Measurements were made in the axial plane at the upper border of the six thoracic vertebrae. Patients were divided into three age groups. Significance of differences in parameters between age groups was calculated. Assessment ratios were considered. It was found that parameters of the three arteries were significantly larger in men than in women (P= < 0.05) and increased with age. Hypertension increased diameters of AA and DA in both genders (P= 0.001) and of PT in men (P= 0.01). Smoking significantly decreased parameters of PT in men (P= 0.01). Diabetes increased parameters of the three arteries in both genders, significantly increased parameters of PT in men (P= <0.05) and parameters of DA in women (P= <0.05). It is concluded that studied parameters were larger in men and increased with age of our patients. Distinctive differences in measurements appeared in hypertensive, smokers, and diabetic patients.

El objetivo fue determinar si el sexo, edad, hipertensión, tabaquismo y la diabetes alteran el diámetro transversal (DT) y área transversal (AT) de la parte ascendente de la aorta (AA), parte descendente de la aorta (AD) y tronco pulmonar (TP), medidos por angiografía por tomografía computadorizada (ATC). Exámenes de ATC de 100 pacientes de 49,5±16,9 años (rango 16­78 años) fueron seleccionados entre enero del año 2009 a mayo del año 2011 por el Departamento de Radiología, Hospital de la Universidad de Jordania, Facultad de Medicina de la Universidad de Jordania, Amman, Jordania para una evaluación avanzada del DT y AT de la AA, AD y TP. Las mediciones se realizaron en el plano axial en el margen superior de las seis vértebras torácicas. Los pacientes fueron divididos en tres grupos según edad. Se determinó la existencia de significancia estadística de los diferentes parámetros entre los grupos etarios. La evaluación de las razones también fueron consideradas. Se encontró que los parámetros de las tres arterias fueron significativamente mayores en los hombres que en las mujeres (p= <0,05) y que aumentaron con la edad. La hipertensión aumentó los diámetros de la AA y AD en ambos sexos (p= 0,001) y del TP en los hombres (p= 0,01). En fumadores disminuyeron significativamente los parámetros del TP en los hombres (p= 0,01). La diabetes aumentó los parámetros de las tres arterias en ambos sexos. Ademas, aumentaron significativamente los parámetros del TP en los hombres (p= <0,05) y los parámetros de la AD en las mujeres (p = <0,05). Se concluye que los parámetros estudiados eran mayores en los hombres y aumentaron con la edad de nuestros pacientes. Diferencias distintivas en las mediciones aparecieron en hipertensos, fumadores y pacientes diabéticos.

Clinical study of the ascending aorta wall motion by velocity vector imaging in patients with primary hypertension / 华中科技大学学报（医学）（英德文版）

We studied the wall motion characteristics of the ascending aorta by velocity vector imaging (VVI) in primary hypertension patients. The ascending aortas both in 30 patients with primary hypertension and 30 normal controls were examined by Acuson sequoia 512 equiped with VVI. The maximum velocity (Vs, Ve) of every point on the anterior wall of ascending aorta both in systole and diastole was measured. The aortic diameter was wider in the hypertension patients than that in the healthy subjects (P0.05). The velocity curves of the anterior wall of ascending aorta both in the hypertension and healthy subjects were regular, and the curve in systole was named S wave and that in diastole named E wave. The velocity of S wave and E wave was slower in the hypertension patients than that in the healthy subjects (P<0.05). The time to peak of S wave on the anterior wall of ascending aorta in systole was shorter in the hypertension patients than in the healthy subjects (P<0.05). VVI could be used to accurately and directly observe the movement character of the ascending aorta walls, which would help us understand the elasticity of great arteries in patients with hypertension.

Ultrasound in the diagnosis and management of intrauterine growth retardation

To evaluate the value of ultrasound in the diagnosis and management strategies of intrauterine growth retardation. Design: A descriptive study. Place and Duration of Study: Radiology Department, Aga Khan University Hospital, Karachi, from April 1998 to August 1999. Patients and The study population comprised of 206 subjects evaluated for suspected intrauterine growth retardation. Grey scale as well as Doppler ultrasound findings were evaluated and compared against post-natal outcome. One hundred and eight out of 206 subjects showed positive imaging results with 40 false positive and 20 false negative subjects. The sensitivity, specificity, positive predictive and negative predictive values were 77.8%, 66.1%, 55.6%, and 45.1% respectively. Forty subjects showed false positive results on imaging [low biophysical profile score and Grey scale biometry discrepancy] while 20 of the subjects showed false negative results [normal on US imaging] when compared with postnatal neonatal body weight criteria. Twenty-two subjects had oligohydramnios with amniotic fluid index below 5 percentile for their respective gestational ages [20%] out of 108. Obstetric and Doppler ultrasound is an accurate method for diagnosis and management of fetal growth retardation

Assessment of effect of angiotensin II receptor antagonist losartan on aortic distensibility in patients with essential hypertension by echocardiography / 华中科技大学学报（医学）（英德文版）

The effects of angiotensin II receptor antagonist losartan on elastic properties of aorta in patients with mild to moderate essential hypertension were assessed. The ascending aortic distensibility in 26 patients (48 +/- 3 years) with mild to moderate essential hypertension before and after 12 weeks of treatment with losartan (50 mg/day) was evaluated by using two-dimensional echocardiography. M-mode measurements of aortic systolic (Ds) and diastolic diameter (Dd) were taken at a level approximately 3 cm above the aortic valve. Simultaneously, cuff brachial artery systolic (SBP) and diastolic (DBP) pressures were measured. Aortic pressure-strain elastic modulus (Ep) was calculated as Dd x (SBP-DBP)/(Ds-Dd) x 1333 and stiffness index beta (beta) was defined as Dd x Ln (SBP/DBP)/(Ds-Dd). Blood pressure significantly decreased from 148 +/- 13/95 +/- 9 mmHg to 138 +/- 12/88 +/- 8 mmHg (systolic blood pressure, P = 0.001; diastolic blood pressure, P = 0.003). There was no significant difference in pulse pressure before and after treatment with losartan (53 +/- 10 mmHg vs 50 +/- 7 mmHg). The distensibility of ascending aorta increased significantly as showed by the significant decrease in pressure-strain elastic modulus from 4.42 +/- 5.79 x 10(6) dynes/cm2 to 1.99 +/- 1.49 x 10(6) dynes/cm2 (P = 0.02) and stiffness index beta from 27.4 +/- 32.9 to 13.3 +/- 9.9 (P = 0.02). Although there was a weak correlation between the percent changes in pressure-strain elastic modulus and stiffness index beta and that in diastolic blood pressure after losartan treatment (r = 0.40, P = 0.04 and r = 0.55, P = 0.004, respectively), no correlation was found between the percent changes in pressure-strain elastic modulus and stiffness index beta and that in systolic blood pressure (r = 0.04, P = 0.8 and r = 0.24, P = 0.2, respectively). Our study demonstrated that angiotensin II receptor antagonist losartan has a beneficial effect on aortic distensibility in patients with mild to moderate essential hypertension and this effect is partly independent of blood pressure reduction.

Discrete subvalvular aortic stenosis in adults.

Discrete subvalvular aortic stenosis is a relatively rare condition in adults. It is often diagnosed during first decade of life especially in association with other congenital malformations. Isolated form of discrete subvalvular aortic stenosis may however silently progress from innocent murmurs of childhood and adolescence to symptomatic left ventricular outflow tract obstruction in adults. Certain overt and subtle morphological abnormalities may underlie the initial expression as well as high recurrence rates after surgical resection of sub aortic membrane. Though surgical resection is the only treatment available, debate on the surgical technique and appropriate timing of surgery continues. Close followup with serial echocardiographic examinations in patients detected to have functional murmurs during childhood may be helpful in early detection of subvalvular aortic stertosis.

Takayasu's arteritis: angiographic and duplex finding

To our knowledge, this is the first report of Takayasu's arteritis from Arabia. Seven patients out of ten were Saudis. Seven were females and three were males. Chest radiograph is invaluable in the evaluation of this disease since it allows visualization of the contour of the aorta with calcification of aortic wall. Carotid duplex can initially suggest the diagnosis based on characteristic sonogrphic features of the disease, however, panarteriography helps in evaluation of the extent of the disease and the state of collateralization