Biomedical Engineering Reference
In-Depth Information
8.7
Coronary and Abdominal Arterial Bypass Grafts
In the previous examples we demonstrated a method to predict high risk and vulner-
ability to aneurysm rupture. A method in treating aneurysms is to use bypass grafts.
In this case study we summarise two similar studies. The first is by Kabinejadian
and Ghista (2011) for coronary arterial bypass grafts (CABG). This study analyses
the design and demonstrate the superiority of the CABG over the conventional end-
to-side anastomosis, which can be demonstrated based on their blood flow patterns
and wall shear stress distributions. The wall compliance using a two-way fluid-
structure interaction and non-Newtonian rheology were applied for physiological
realism. The second study is by Qiao et al. (2015) for a DeBakey III type aortic
dissection. An aortic dissection is when a tear in the inner wall of the aorta causes
blood to flow between the layers of the wall of the aorta, forcing the layers apart.
The type of dissection is classified based on the DeBakey system (Fig.
8.59
) which
considers the original tear location and extent of the dissection (localized to either
the ascending aorta or descending aorta, or involves both the ascending and de-
scending aorta).
Two different strategies for bypassing the dissection were undertaken. The first
is to create the bypass between the ascending aorta and abdominal aorta, and the
other is a bypass between the left subclavian artery and abdominal aorta. Their
results showed that blood flow velocity, pressure and vessel wall displacement of
false lumen all reduced after bypassing.
Fig. 8.59
The DeBaky classification of aortic dissection. Type I—Originates in ascending aorta,
propagates at least to the aortic arch and often distally. Type II—Originates in ascending aorta
and is confined to the ascending aorta. Type III—Originates in descending aorta, rarely extends
proximally but will extend distally. (Adapted from Wikicommons)
Search WWH ::
Custom Search