Biomedical Engineering Reference
In-Depth Information
devices to measure pressure inside the aneurysm sac are described. The future trends
for stent-graft's are also addressed highlighting the features of a smart stent-graft.
A model of an AAA is presented along with a description of the development of a
flexible pressure sensor.
2
Endovascular Aneurism Repair
Since the early 1950s, aneurysms' standard treatment has consisted of an open
surgery (done under general anesthesia) and the replacement of the diseased
segment of the aorta by a synthetic prosthetic graft [
6
], Fig.
2
. In spite of its
invasiveness and the fact of being limited to fit patients, this treatment is still a
current practice and less invasive techniques, namely total laparoscopy and assisted
laparoscopy, are being studied to minimize its disadvantages [
7
].
In the beginning of the 1990s, Volodos (in Ukraine) and Parodi (in Argentina)
demonstrated that endovascular aneurysm repair (EVAR) was a safe and feasible
practice [
8
]. This surgical procedure is done percutaneously and it is minimally
invasive, Fig.
3
. Typically, a small incision is made in each groin to expose the
femoral arteries. Then, with the aid of catheters and guidewires, a stent-graft is
guided to the affected artery segment allowing blood to pass without exerting
pressure in the aneurysm sac and, thus, preventing wall rupture.
The first procedures resulted in several complications, some due to the inherent
learning process, while others were due to the devices' inefficiency. With time, many
of the problems have been solved due to the accumulation of experience and the
introduction of better devices but, nevertheless, some problems still occur. These
Fig. 2
Conventional
treatment of AAA's, open
surgery to insert a synthetic
graft
