Stent Graft Repair of an Abdominal Aortic Aneurysm
What is an abdominal aortic aneurysm (AAA)?
The aorta is the largest artery in the body. It carries blood from the
heart to the rest of the body. The aorta is normally 2 to 3 centimeters
in size. An aneurysm is a weakening in the vessel wall that results in dilatation,
or “ballooning” of the vessel wall. If left untreated, an aneurysm
may continue to grow and rupture, resulting in life-threatening bleeding.
Aneurysms can occur anywhere in the body. An AAA occurs in the aorta between
the kidneys and the pelvis. Small aneurysms rarely rupture, so your physician
may decide that it is best to just monitor its development through periodic
check-ups rather than repair the aneurysm. However, if the aneurysm continues
to grow beyond 5.0 centimeters, your physician may recommend treatment.

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How is an abdominal aortic aneurysm (AAA) treated?
Conventional Surgical Procedure
The open surgical approach involves making a large incision into the abdomen
in order to expose the aorta and its aneurysm. Clamps are applied to the arteries
above and below the aneurysm so that the artery may be directly cut open. The
section of artery that is abnormally enlarged is replaced by a synthetic tube,
which the vascular surgeon sews into place. The clamps are removed and blood
flow is restored through the repaired artery. This operation has enjoyed durable
success. However, it is a major surgery. There is an approximately 5% chance
of fatal complications. The patient usually spends 7 to 10 days in the hospital
and is not back to feeling like their regular self for 2 to 3 months.
Endovascular Stent-Graft Procedure
Recent advances in minimally invasive surgery have made the endovascular
repair of an AAA possible. Stent-graft repair is usually performed by an
Interventional Radiologist and Vascular Surgeon team in the operating room.
The procedure is usually performed under general or spinal anesthesia. Incisions
are made in each of the two groins, where the arteries at these locations
are exposed. Under x-ray guidance, a delivery catheter (tube) containing
a vascular graft iel in your leg into your aorta. At the tip of the catheter
are a deflated balloon and a tightly wrapped cloth graft. When properly
positioned, the graft is secured in place by inflating the balloon and opening
the graft to the diameter needed to prevent blood flow into the aneurysm.
The balloon is then deflated and removed along with the catheter. At each
end of the graft are hooks that help secure it to the inner walls of the
aorta. The graft allows blood flow to continue through the aorta to the
arteries in the pelvis and legs, without filling the aneurysm.s guided up
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Most patients remain in the hospital 1 -3 days following the procedure,
and then require approximately 2 weeks recovery at home. The successful
insertion of an aortic endograft has less operative stress on the body,
no painful abdominal incision, less blood loss, a lower operative mortality,
reduced length of hospital stay, and much faster recovery when compared
to the open surgical approach. Over time, the aneurysm may shrink, minimizing
future threat of rupture. However, there remains a 5-10% chance that the
stent-graft may not adequately exclude all blood from flowing in the aneurysm.
This is called an "endoleak". In these unusual occurrences, another
catheter based minimally invasive procedure or other surgery may become
necessary. Because of this, a more intensive follow-up is required. CT scans
are periodically obtained. It is important that patients adhere to follow-up
appointments with their doctor and have regular CT scans during the first
year after the procedure to ensure that the stent-graft is properly positioned
and effective. |
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What is an "endoleak" and how is it treated?
An "endoleak" is persistent flow into the aneurysm. There are several
types of endoleaks, but the most common include a leak resulting from
an incomplete seal of the stent-graft to the aortic wall, or due to opposing
blood flow from collateral vessels. An incomplete stent-graft seal may be repaired
by placing an additional expandable stent over this area to tack the loose stent-graft
against the aortic wall. Collateral vessels may be embolized to block the blood flow to the aneurysm.
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