| Abdominal
Aortic Aneurysm Repair
(Abdominal Aneurysm - Open Repair,
AAA Repair, Triple A Repair, Abdominal Aneurysmectomy,
Endovascular Aneurysm Repair, EVAR)
Procedure Overview
What is an abdominal
aortic aneurysm repair?
Abdominal aortic aneurysm (AAA)
repair is a procedure used to treat an aneurysm
(abnormal enlargement) of the abdominal aorta.
Repair of an abdominal aortic aneurysm may be
performed surgically through an open incision
or in a minimally-invasive procedure called endovascular
aneurysm repair (EVAR).
What is an abdominal
aortic aneurysm?
An abdominal aortic aneurysm,
also called AAA or triple A, is a bulging, weakened
area in the wall of the aorta (the largest artery
in the body) resulting in an abnormal widening
or ballooning greater than 50 percent of the normal
diameter (width).
The aorta extends upward from
the top of the left ventricle of the heart in
the chest area (ascending thoracic aorta), then
curves like a candy cane (aortic arch) downward
through the chest area (descending thoracic aorta)
into the abdomen (abdominal aorta). The aorta
delivers oxygenated blood pumped from the heart
to the rest of the body.
The most common location of
arterial aneurysm formation is the abdominal aorta,
specifically, the segment of the abdominal aorta
below the kidneys. An abdominal aneurysm located
below the kidneys is called an infrarenal aneurysm.
An aneurysm can be characterized by its location,
shape, and cause.
The shape of an aneurysm is
described as being fusiform or saccular, which
helps to identify a true aneurysm. The more common
fusiform-shaped aneurysm bulges or balloons out
on all sides of the aorta. A saccular-shaped aneurysm
bulges or balloons out only on one side.
A pseudoaneurysm, or false aneurysm,
is an enlargement of only the outer layer of the
blood vessel wall. A false aneurysm may be the
result of a prior surgery or trauma. Sometimes,
a tear can occur on the inside layer of the vessel
resulting in blood filling in between the layers
of the blood vessel wall, creating a pseudoaneurysm.
The aorta is under constant
pressure as blood is ejected from the heart. With
each heart beat, the walls of the aorta distend
(expand) and then recoil (spring back), exerting
continual pressure or stress on the already weakened
aneurysm wall. Therefore, there is a potential
for rupture (bursting) or dissection (separation
of the layers of the aortic wall) of the aorta,
which may cause life-threatening hemorrhage (uncontrolled
bleeding) and, potentially, death. The larger
the aneurysm becomes, the greater the risk of
rupture.
Because an aneurysm may continue
to increase in size, along with progressive weakening
of the artery wall, surgical intervention may
be needed. Preventing rupture of an aneurysm is
one of the goals of therapy.
Types of abdominal aneurysm
repair:
There are two approaches to
abdominal aortic aneurysm repair. The standard
surgical procedure for AAA repair is called the
open repair. A newer procedure is the endovascular
aneurysm repair (EVAR).
- abdominal aortic aneurysm
open repair:
Open repair of an abdominal aortic aneurysm
involves an incision of the abdomen to directly
visualize the aortic aneurysm. The procedure
is performed in an operating room under general
anesthesia. The surgeon will make an incision
in the abdomen either lengthwise from below
the breastbone to just below the navel or across
the abdomen and down the center. Once the abdomen
is opened, the aneurysm will be repaired by
the use of a long cylinder-like tube called
a graft. Grafts are made of various materials,
such as Dacron (textile polyester synthetic
graft) or polytetrafluoroethylene (PTFE, a non-textile
synthetic graft). The graft is sutured to the
aorta connecting one end of the aorta at the
site of the aneurysm to the other end of the
aorta. Open repair remains the standard procedure
for an abdominal aortic aneurysm repair.
- endovascular aneurysm
repair (EVAR)
EVAR is a minimally-invasive (without a large
abdominal incision) procedure performed to repair
an abdominal aortic aneurysm. EVAR may be performed
in an operating room, radiology department,
or a catheterization laboratory. The physician
may use general anesthesia or regional anesthesia
(epidural or spinal anesthesia). The physician
will make a small incision in each groin to
visualize the femoral arteries in each leg.
With the use of special endovascular instruments,
along with x-ray images for guidance, a stent-graft
will be inserted through the femoral artery
and advanced up into the aorta to the site of
the aneurysm. A stent-graft is a long cylinder-like
tube made of a thin metal framework (stent),
while the graft portion is made of various materials
such as Dacron or polytetrafluoroethylene (PTFE)
and may cover the stent. The stent helps to
hold the graft in place. The stent-graft is
inserted into the aorta in a collapsed position
and placed at the aneurysm site. Once in place,
the stent-graft will be expanded (in a spring-like
fashion), attaching to the wall of the aorta
to support the wall of the aorta. The aneurysm
will eventually shrink down onto the stent-graft.
The physician will determine
which surgical intervention is most appropriate,
either open repair or EVAR.
Reasons for the Procedure
Reasons an abdominal aortic
aneurysm repair may be performed include, but
are not limited to, the following:
- to prevent the risk of rupture
- to relieve symptoms
- to restore a good blood flow
- size of aneurysm greater
than 5 centimeters in diameter (about two inches)
- growth rate of aneurysm of
more than 0.5 centimeter (about 0.2 inch) over
one year
- when risk of rupture outweighs
the risk of surgery
- emergency life-threatening
hemorrhage (uncontrolled bleeding)
There may be other reasons for
your physician to recommend an abdominal aortic
aneurysm repair.
Risks of the Procedure
As with any surgical procedure,
complications can occur. Some possible complications
may include, but are not limited to, the following:
- open repair: myocardial infarction
(heart attack)
- irregular heart rhythms (arrhythmias)
- bleeding during or after
surgery
- injury to the bowel (intestines)
- limb ischemia (loss of blood
flow to legs/ feet)
- embolus (clot) to other parts
of the body
- infection of the graft
- lung problems
- kidney damage
- spinal cord injury
- EVAR: damage to surrounding
blood vessels, organs, or other structures by
instruments
- groin wound infection
- groin hematoma (large blood-filled
bruise)
- endoleak (continual leaking
of blood out of the graft and into the aneurysm
sac with potential rupture)
Patients who are allergic to
or sensitive to medications, contrast dyes, iodine,
shellfish, or latex should notify their physician.
There may be other risks depending
upon your specific medical condition. Be sure
to discuss any concerns with your physician prior
to the procedure.
Before the Procedure
Your physician will explain
the procedure to you and offer you the opportunity
to ask any questions that you might have about
the procedure.
You will be asked to sign a
consent form that gives permission to do the procedure.
Read the form carefully and ask questions if something
is not clear.
In addition to a complete medical
history, your physician may perform a physical
examination to ensure you are in good health before
you undergo the procedure. You may also undergo
blood tests and other diagnostic tests.
You will be asked to fast for
eight hours before the procedure, generally after
midnight.
If you are pregnant or suspect
that you are pregnant, you should notify your
physician.
Notify your physician if you
are sensitive to or are allergic to any medications,
latex, iodine, tape, contrast dyes, and anesthetic
agents (local or general).
Notify your physician of all
medications (prescribed and over-the-counter)
and herbal supplements that you are taking.
Notify your physician if you
have a history of bleeding disorders or if you
are taking any anticoagulant (blood-thinning)
medications, aspirin, or other medications that
affect blood clotting. It may be necessary for
you to stop these medications prior to the procedure.
If you smoke, you should stop
smoking as soon as possible prior to the procedure,
in order to improve your chances for a successful
recovery from surgery and to improve your overall
health status.
You may receive a sedative prior
to the procedure to help you relax.
The areas around the surgical
site may be shaved.
Based upon your medical condition,
your physician may request other specific preparation.
During the Procedure
Abdominal
aortic aneurysm repair requires a stay in a hospital.
Procedures may vary depending on your condition
and your physician's practices.
Generally, an abdominal aortic
aneurysm repair follows this process:
- You will be asked to remove
any jewelry or other objects that may interfere
with the procedure.
- You will be asked to remove
your clothing and will be given a gown to wear.
- You will be asked to empty
your bladder prior to the procedure.
An intravenous (IV) line will
be started in your arm or hand. Additional catheters
will be inserted in your neck and wrist to monitor
the status of your heart and blood pressure, as
well as for obtaining blood samples. Alternate
sites for the additional catheters include the
subclavian (under the collarbone) area and the
groin.
Abdominal aortic aneurysm
- open repair:
You will be positioned on the
operating table, lying on your back.
The anesthesiologist will continuously
monitor your heart rate, blood pressure, breathing,
and blood oxygen level during the surgery. Once
you are sedated, a breathing tube will be inserted
through your throat into your lungs and you will
be connected to a ventilator, which will breathe
for you during the surgery.
A catheter will be inserted
into your bladder to drain urine.
The skin over the surgical site
will be cleansed with an antiseptic solution.
Once all the tubes and monitors
are in place, the physician will make an incision
(cut) down the center of the abdomen from immediately
below the breastbone to below the navel or across
the abdomen from underneath the left arm across
to the center of the abdomen and down to below
the navel.
The physician will place a clamp
on the aorta above and below the site of the aneurysm.
This will temporarily interrupt the flow of blood.
The physician will cut open
the aneurysm sac and suture into place a long
tube called the graft. This will connect both
ends of the aorta together.
The clamps will be removed and
the physician will wrap the wall of the aneurysm
around the graft, suturing the aorta back together.
Endovascular aneurysm
repair, EVAR:
You will be placed in a supine
(on your back) position on the operating table
or on a procedure table in a radiology suite.
The anesthesiologist will continuously
monitor your heart rate, blood pressure, breathing,
and blood oxygen level during the surgery. Once
you are sedated, a breathing tube may be inserted
through your throat into your lungs and you will
be connected to a ventilator, which will breathe
for you during the surgery.
The physician may choose regional
anesthesia instead of general anesthesia. Regional
anesthesia is medication delivered through an
epidural (in the back) to numb the area to be
operated on. You will receive medication to help
you relax and analgesic medication for pain relief.
The physician will be able to talk to you during
the procedure. The physician will determine which
type of anesthesia is appropriate.
The physician will make an incision
in each groin to expose the femoral arteries.
Using fluoroscopy (a type of x-ray "movie"
that transmits images to a TV-like monitor), the
physician will insert a needle into the femoral
artery through which a guidewire will be passed
and advanced to the aneurysm site. The needle
will be removed and a sheath slid over the guidewire.
An aortogram (injection of contrast
dye to visualize the position of the aneurysm
and adjacent blood vessels) will be performed.
The physician will use special
endovascular instruments and x-ray images for
guidance. A stent-graft will be inserted through
the femoral artery and advanced up into the aorta
to the site of the aneurysm.
The stent-graft, in a collapsed
position until after it is inserted, will be advanced
up into the aorta and situated at the aneurysm
site. The stent graft will be expanded (in a spring-like
fashion) and attached to the wall of the aorta.
An aortogram will be repeated
to check for an endoleak (blood leaking out into
the aneurysm sac) of the stent-graft.
Once no leak has been determined,
the instruments will be removed.
Procedure completion,
both methods:
The incisions will be sutured
back together.
A sterile bandage/dressing will
be applied.
After an open procedure, a tube
may be inserted through your mouth or nose into
your stomach to drain stomach fluids.
You will be transferred from
the operating table to a bed, then taken to the
intensive care unit (ICU) or the post-anesthesia
care unit (PACU).
After the Procedure
In the hospital - open
repair:
After the procedure, you may
be taken to the recovery room before being taken
to the intensive care unit (ICU) to be closely
monitored. Alternatively, you may be taken directly
to the ICU from the operating room. You will be
connected to monitors that will constantly display
your electrocardiogram (ECG or EKG) tracing, blood
pressure, other pressure readings, breathing rate,
and your oxygen level.
You may have a tube in your
throat so that breathing can be assisted with
a ventilator (breathing machine) until you are
stable enough to breathe on your own. As you continue
to wake up from the anesthesia and start to breathe
on your own, the breathing machine will be adjusted
to allow you to take over more of the breathing.
When you are awake enough to breathe completely
on your own and you are able to cough, the breathing
tube will be removed.
After the breathing tube is
out, your nurse will assist you to cough and take
deep breaths every two hours. This may be uncomfortable
due to soreness, but it is extremely important
that you do this in order to keep mucus from collecting
in your lungs and possibly causing pneumonia.
Your nurse will show you how to hug a pillow tightly
against your chest while coughing to help ease
the discomfort.
You may receive pain medication
as needed, either by a nurse, through an epidural
catheter, or by administering it yourself through
a device connected to your intravenous line.
You may be on special IV medications
to help your blood pressure and your heart, and
to control any problems with bleeding. As your
condition stabilizes, these medications will be
gradually decreased and discontinued as your condition
allows.
Once the breathing tube has
been removed and your condition has stabilized,
you may start liquids to drink. Your diet may
be gradually advanced to more solid foods as you
are able to tolerate them.
If you have a drainage tube
in your stomach, you will not be able to drink
or eat until the tube is removed. The drainage
tube will be removed when your intestinal function
has returned to normal, usually two to three days
after the procedure.
When your physician determines
that you are ready, you will be moved from the
ICU to a post-surgical nursing unit. Your recovery
will continue to progress. Your activity will
be gradually increased as you get out of bed and
walk around for longer periods of time. Your diet
will be advanced to solid foods as tolerated.
Arrangements will be made for
a follow-up visit with your physician.
In the hospital - EVAR:
You may or may not be taken
to the intensive care unit (ICU); however, you
may be taken to a post anesthesia care unit (PACU).
You will be connected to monitors that will constantly
display your electrocardiogram (ECG or EKG) tracing,
blood pressure, other pressure readings, breathing
rate, and your oxygen level.
You will remain in either the
ICU or PACU for a designated period of time and
then transferred to a regular nursing care unit.
You will be given pain medication
for incisional pain or you may have had an epidural
(a type of anesthesia that involves continually
infusing an anesthetic medication through a thin
catheter (hollow tube) into the space that surrounds
the spinal cord in the lower back, causing numbness
in the lower body, abdomen, and/or chest) placed
during surgery which will help with postoperative
pain.
Your activity will be gradually
increased as you get out of bed and walk around
for longer periods of time. Your diet will be
advanced to solid foods as tolerated.
Arrangements will be made for
a follow-up visit with your physician.
At home:
Once you are home, it will be
important to keep the surgical area clean and
dry. Your physician will give you specific bathing
instructions. The sutures or surgical staples
will be removed during a follow-up office visit,
in the event they were not removed before leaving
the hospital.
The surgical incision may be
tender or sore for several days after an aneurysm
repair procedure. Take a pain reliever for soreness
as recommended by your physician.
You should not drive until your
physician tells you to. Other activity restrictions
may apply.
- Notify your physician to
report any of the following:
- fever and/or chills
- redness, swelling, or bleeding
or other drainage from the incision site
- increase in pain around the
incision site
- Your physician may give you
additional or alternate instructions after the
procedure, depending on your particular situation.
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