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Specific Arterial Disease
Published in Wilmer W Nichols, Michael F O'Rourke, Elazer R Edelman, Charalambos Vlachopoulos, McDonald's Blood Flow in Arteries, 2022
Medical treatment entails the use of antihypertensive therapies, initially administered intravenously, monitored invasively, to reduce peak aortic systolic pressure and to prevent extension of dissection, in the expectation that blood will clot in the false lumen and that fibrous repair will occur. Sometimes reentry occurs in the aorta, with a second intimal tear, and a “double barrel” aorta is created. Surgical treatment entails repair of the intimal split and of secondary damage. Often, replacement of the whole ascending aorta and the aortic valve is necessary (Mehta et al., 2002). Surgery to the descending aorta when required, as by progressive enlargement of the false aneurysm, especially beyond 22 mm in diameter (Isselbacher, 2007; Song et al., 2007) may be undertaken with endovascular stent-grafts (Chuter, 2009). Enlargement of an aneurysm, once developed, tends to be progressive, be this a thoracic or abdominal aneurysm, and is initially caused by age, trauma, hypertension or Marfan syndrome. All carry the risk of rupture; this is greater when the aneurysm is large or risk factors are uncontrolled. Surgical treatment is best undertaken now with endovascular repair (Mani et al., 2009; Sicard, 2009).
Fetal echocardiography
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Caroline K. Lee, Erik C. Michelfelder, Gautam K. Singh
While the four-chamber view is the only view of the heart required for standard second-and third-trimester fetal examinations, the addition of outflow tracts has been shown to yield higher detection of congenital heart anomalies than the four-chamber view alone (21–23). From the four-chamber view, sweeping cephalad will demonstrate the ventricular outflow tracts and the relationship of the great arteries. The aorta arises from the posterior LV and aims toward the fetal right shoulder (Fig. 6). The pulmonary artery (PA) arises from the anterior RV and courses leftward and posteriorly, crossing the aorta, extending to the ductus arteriosus, which then meets the descending aorta. Continuity between the mitral and aortic valves is demonstrated in this view, and the anterosuperior aspect of the ventricular septum can be interrogated to rule out a VSD. Discontinuity of the mitral and aortic valves is characteristic of double-outlet RV lesions.
Clinical Applications of Dual Energy CT in Neuroradiology
Published in Katsuyuki Taguchi, Ira Blevis, Krzysztof Iniewski, Spectral, Photon Counting Computed Tomography, 2020
Rajiv Gupta, Maarten Poirot, Rick Bergmans
Figure 2.13 shows images of the ascending and descending aorta at the left of the main pulmonary artery trunk. As can be seen, and as would be expected, the intensity of iodine increases as the virtual energy level approaches the k-edge of iodine (33.4 keV). We briefly describe how this feature can be used to mitigate metal and beam-hardening artifacts, and to improve the contrast resolution of an image.
Operative repair of three ascending aortic dissections in one day at Baylor University Medical Center
Published in Baylor University Medical Center Proceedings, 2022
Charles Stewart Roberts, Lauren Zammerilla Westcott
The operation for ascending aortic dissection involves several formidable perfusion challenges. Replacement of the ascending aorta and proximal arch is generally necessary in ascending aortic dissection, and so the circulation must be artificially supported, on either side (heart side and arch side), to accomplish this surgical task. On the proximal side of the entry aortic tear, the heart must remain viable through cardioplegia and its function replaced by CPB. On the distal side is the aortic arch and its branches to the brain, and the descending aorta and its branches to the spine, abdomen, and legs. This requires various circulatory support measures, including CPB, cerebral perfusion, and, at times, complete cessation of perfusion, along with body hypothermia. The operation can extend easily beyond 6 hours without an efficient plan.
Clinical features and echocardiographic findings of isolated foramen ovale restriction in foetuses
Published in Journal of Obstetrics and Gynaecology, 2022
Tolga Akbaş, Fadli Demir, Sevcan Erdem, Berivan Çağnıs, Ferda Özlü, Selim Büyükkurt, Nazan Özbarlas
Right ventricle and LV diastolic dimensions were measured just below the atrioventricular (AV) valves, the widest part at the end of the diastole, in the appearance of a four-chamber view. The widest length from each atrium's sidewalls to the atrial septum's edge was measured at end of systole. The dimensions of aorta and pulmonary artery and their relationship with each other were evaluated. The great arteries' dimensions were recorded by measuring their largest diameters at the end of the systole. Ventricular and atrial enlargements were determined based on published standard measurements for gestational age-based dimensional measurements. The ductal view was obtained by aligning the imaging plane with the right ventricular outflow tract and the main pulmonary artery. The ductus arteriosus (DA) was evaluated in sagittal or longitudinal axis views in 2D echocardiography. The ascending aorta's size and shape, the transverse arch, and the descending aorta were visualised. The presence of antegrade blood flow in the aorta and pulmonary artery and velocity was recorded using colour Doppler (Sharland and Allan 1992; Rychik et al. 2004; Donofrio et al. 2014).
A modified method of computed fluid dynamics simulation in abdominal aorta and visceral arteries
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Yun Shi, Chen Peng, Junzhen Liu, Hongzhi Lan, Chong Li, Wang Qin, Tong Yuan, Yuanqing Kan, Shengzhang Wang, Weiguo Fu
The multiple flow BCs imposed on the inlet and outlets have been implemented in the numerical computational modeling and simulation of the aortic model. Pirola et al. reconstructed a thoracic aortic model with supra-aortic branches, and measured the flow rates at the ascending aorta and descending aorta by 2D PCMRI. The difference of the flow rates of the ascending aorta and descending aorta was dispensed to the supra-aortic branches according to the relative cross-sectional areas (Pirola et al. 2017). With the reconstruction of patient-specific AAA models including visceral arteries, Boutsianis et al. (2009) dispensed the flow rates derived from experiment to the inlet and outlets, while Piccinelli et al. (2013) dispensed the 1/20 of the flow rates at the inlet equally to the outlets of visceral arteries. Tang et al. reconstructed an abdominal aorta model including the visceral arteries of young healthy adults, and measured the aortic flow rates at SC and IR levels by 2D PCMRI, the difference of flow rates of SC and IR aorta was dispensed to CA, SMA and bilateral RAs according to the percentage quoted from literature (Tang et al. 2006). The flows dispensed to the visceral arteries were used as flow BCs (Bonfanti et al. 2018).