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Cardiovascular system
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
The aorta is the largest artery in the human body and transports oxygenated blood from the heart to the rest of the body. The thoracic aorta consists of the ascending, arch and descending aorta. There are three major branches from the thoracic aorta, all from the aortic arch: the brachiocephalic, left common carotid and left subclavian arteries. The aorta passes into the abdomen through the diaphragmatic hiatus at T12. The abdominal aorta has three ventral branches (coeliac axis, superior mesenteric and inferior mesenteric arteries) and two lateral branches (right and left renal arteries).
Coanda Effect in a Human Body
Published in Noor A. Ahmed, Coanda Effect, 2019
In endovascular aortic repair, a graft is inserted into the aorta to strengthen the aorta without removing the aneurysm. The surgeon first inserts a catheter into an artery in the groin (in the upper thigh) and using the X-ray display, threads the graft, often called a stent graft, into the aorta to the aneurysm. The graft is then expanded inside the aorta, which helps to lock it in place and form a stable channel for blood flow. The graft strengthens the weakened section of the aorta and prevents the aneurysm from rupturing. The endovascular aortic repair process [37] is shown in Figure 5.13.
Detection of Calcification from Abdominal Aortic Aneurysm
Published in Ayman El-Baz, Jasjit S. Suri, Cardiovascular Imaging and Image Analysis, 2018
Safa Salahat, Ahmed Soliman, Harish Bhaskar, Tim McGloughlin, Ayman El-Baz, Naoufel Werghi
The aorta is the largest blood vessel in the human body starting from the left ventricle of the heart going down into the abdomen. An aneurysm is an irreversible localized dilatation of a vessel [1–2]. Abdominal aortic aneurysm (AAA) is a cardiovascular disease which is identified when the abdominal aorta expands, reaching a maximum diameter of 3 cm or larger. AAAs with smaller maximum diameter are considered healthy (see Figure 9.1) [3–4]. AAA is asymptomatic in most cases until rupture, or being occasionally discovered when the patient has radiologic testing for other purposes [4–6].
CFD analysis of the hyper-viscous effects on blood flow across abdominal aortic aneurysm in COVID patients: multiphysics approach
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Shankar Narayan S., Anuradha Bhattacharjee, Sunanda Saha
The human aorta contains three layers: the inner layer (intima), the middle layer (media), and the outer layer, which can be more than an inch broad in certain locations (adventitia). The aorta can develop issues that endanger the heart and the blood flow to the rest of the body (Witmer 2008; Oomens et al. 2017; Gasser 2017). An aortic aneurysm is a weak spot or bulge on the aorta’s wall that can develop anywhere along the vessel’s length. Two issues can result from aortic aneurysms. A hole, known as a rupture, might form in the weaker or inflated region, allowing blood to leak into the body. The layers of the artery wall can be separated by the blood that is forced through the aorta, enabling blood to accumulate there and further dividing the arterial wall. Aortic dissections occur when the layers of the aorta, which carry blood from the heart, separate. This may result in aortic rupture or reduced blood supply to organs (ischemia).
Devices for thoracic endovascular aortic repair of type B aortic dissection: is there any chance for Marfan syndrome?
Published in Expert Review of Medical Devices, 2020
Luigi Lovato, Mariano Cefarelli, Emanuele Gatta, Marco Di Eusanio, Rossella Fattori
The concept of endovascular aortic repair is the exclusion of the diseased aortic segment (aneurysm, ulcer, false lumen) from circulation. Aortic SG are composed of a metal self-expandable stent frame covered with or externally attached to a woven fabric that is sewn to them. The graft is compressed into a sheath and it is deployed through a release system that is driven by the operator. Once it is released the SG expands and attaches itself to the aortic wall (aortic neck) proximal and distal to the diseased segment. The proper and durable apposition is based on several device-related factors that include the magnitude and distribution of the intrinsic SG radial forces and the SG conformability, but it is also influenced by the aortic anatomy and the right oversizing [26,27]. Safety and efficacy of the repair depend on a correct SG deployment, which in turns derives from an appropriate procedural planning based on the accurate assessment of anatomical elements including length, diameter, wall atheroma and aortic neck angulation. The pre-procedural evaluation must be even more meticulous in TBAD, with additional anatomical details to be considered like the level and number of entry and re-entry tears and visceral and epiaortic vessel relationship to the true and false lumen.
Numerical simulation of two-phase non-Newtonian blood flow with fluid-structure interaction in aortic dissection
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Yonghui Qiao, Yujie Zeng, Ying Ding, Jianren Fan, Kun Luo, Ting Zhu
Aortic dissection is a serious hazardous cardiovascular disease in which blood enters the middle layer of the aortic wall through an entrance tear. This causes the layer to split, forming a “true lumen” (TL) and a “false lumen” (FL) (Wan Ab Naim et al. 2014). Currently, there is a lack of sufficient understanding of the pathogenesis and pathophysiological changes involved in aortic dissection. Detailed knowledge of flow-related variables such as wall pressure and wall shear stress (WSS) can provide better insight into the progression of aortic dissection, aid clinicians in tailoring treatment to individual patients, and optimize management of the disease. In the last several decades, many researchers have applied numerical approaches to obtain the hemodynamic parameters of aortic dissection (Sun & Chaichana 2016). Khanafer and Berguer (2009) found that the highest shear stress occurs in the medial layer, and this may contribute to the dissection. Tse et al. (2011) investigated blood flow in a pre-aneurismal aorta model and inferred that elevated TAWSS would extend the tear. Ab Naim et al. (2016) reported vortical structure in the FL and its interaction with WSS to predict thrombus formation.