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25 Cards in this Set

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What is the per year chance of aortic rupture in a 5 cm aneurysm?
7%
6 cm?
15%
7 cm?
25%
What is the most common type of aortic stent graft used?
Aorto-biiliac
How does it set into the vessel, since stent is so much smaller than vascular lumen?
Has fixation devices proximally and distally which set into the aorta and iliac vessels
In order to use stent graft, what do you need structurally?
Need essentiall normal sized aortic lumen below the renals above where the aneurysm begins (26mm or less) so that you can set the proximal end of your graft. Likewise, the aneurysm cannot extend far into the iliacs, which must be less than 13 mm in diameter.
What other patients may not do well with stent grafts?
Very calcified vessels -- difficult to set graft into them


Any patient with accessory renal artery -- placing graft will infarct the supplied part of the kidney.



Severely angled aneurysm neck
How many types of aortic stent graft leaks are there?
5 (I-V)
What is a type I leak?
Leak occurs at the site of fixation of the graft (upper or lower points), with blood leaking around the graft and into the aneurysm sac that way.
What is type II leak?
Retrograde endoleak
What is retrograde endoleak?
Blood from the vessels that are supplied by the native aorta, which are now no longer perfused with stent in place, begin to flow in a retrograde direction, leaking into the native aortic lumen (aneurysm sac).
Which vessels are these?
IMA


Lumbars
What is type III?
Stent itself ruptures
What cases does this usually occur in?
Modular grafts, which are assembled in vivo, as opposed to the ones that are inserted all as one unit. Modular grafts can come apart again, and this would be considered rupture of the stent.
What is type IV?
Graft porosity.

Leakage of blood through pores of graft material. Occurs all the time, and is not clinically significant.
What is Type V?
Endotension leak. The aneurysm sac is enlarging, but no source of bleeding can be identified.
How are Type Vs handled?
The graft is removed and the aneurysm is surgically repaired.
What is the most common type of graft leak?
Type II
What are the risk factors for Type I leak?
Wide or short upper (infrarenal) neck.
What does a type II leak look like?
They will show you an axial or sagittal section with the IMA in plane. The IMA will be opacified with contrast. That means its patent and blood is flowing. You know that the contrast didn't get into it in an anterograde direction, so blood has to be flowing retrograde through it. You would ask for additional sections to demonstrate contrast leaking back into the lumen of the aneurysm sac.


Similarly, they could show you the same thing with a lumbar, where you would see an opacified blood vessel posteriorly (posterior to graft, as opposed to IMA which is anterior to graft).
What else is always present in Type II endoleak?
There also is always at least one vessel flowing back out in an anterograde direction to allow the endoleak to continue, but this may be more difficult to identify, especially on the early images normally captured for vascular studies.
Another thing:
If you see a type I leak and a patent opacified vessel leaving the sac, you can assume that that vessel is acting as the egress vessel (it would be unlikely that both are acting as sites of ingress)
How are type I leaks handled?
Put glue around the leaking part of the stent
How are type II leaks handled?
3-6 month follow up, as most will spontaneously resolve.


If on follow up, there is no increase in sac size, then you can just continue to watch (even if leak is still visualized).
What are other non-leak common complications of graft placement?
A-V fistulas (see contrast going up iliac vein or IVC during arterial phase)



Thrombosis of graft



Infarct (renal)