Neurointerventional Radiology Procedures
EXTRACRANIAL (BRACHIOCEPHALIC) ANGIOPLASTY
(brachiocephalic) atherosclerosis is a hardening of the arteries that
supply blood to the head and neck (carotid and vertebral arteries), thus
causing narrowing and eventually blockage of these vessels.
Atherosclerosis of the carotid arteries often cause transient ischemic attacks
(TIAs or ministrokes) because pieces of the material that forms the
blockage (plaque) and blood clots that form on the plaque break off and
are carried into the head where they can block vessels supplying blood
the brain. If the blockage produced by this material is small and breaks
up quickly, a TIA occurs. If there is blockage of a larger vessel or
the blockage doesn't break up right away, a stroke results. Blockage of
the vertebral arteries usually causes symptoms because of decreased
blood flow to part of the brain, not because of pieces of plaque and
clot breaking off. The symptoms of blockage of these vessels may get
better and worse, or they may suddenly appear if a stroke occurs.
Extracranial atherosclerosis should be treated when it is found. If
there are reasons why medical therapy or surgery is not recommended
(such as a severe narrowing (especially in a location that cannot be
safely reached by the surgeon), poor health, or previous radiation
therapy to the neck), angioplasty and possibly stenting may be
recommended. A catheter is placed into an artery (usually in the leg,
similar to an angiogram of the heart) and threaded up to the vessel with
the blockage. A small catheter with a balloon on the tip is
inserted at the site of the blockage and inflated to open the
vessel; occasionally a stent (a metal tube designed to keep the vessel
open) is placed. Blood thinners are given during the procedure and for a
short time after to prevent blood clots as it starts to heal. Patients
can usually go home later the same day or the next day.
Carotid angioplasty with stenting (CAS):
What to expect:
- 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. An
additional catheter will be inserted in your wrist to monitor your blood
pressure, as well as for obtaining blood samples. One or more
additional catheters may be inserted into your neck to monitor your
heart function. Alternate sites for any additional catheters include the
subclavian (under the collarbone) area and the groin.
- 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.
The groin area (or arm) will be cleaned with antiseptic soap.
- CAS is usually performed under local anesthesia. You will not feel
the area being operated on. You will receive a sedative medication in
your IV before the procedure to help you relax. However, you will likely
remain awake, but sleepy, during the procedure.
- The insertion area in the groin will be covered with sterile towels and a sheet.
- A numbing medication (lidocaine or xylocaine) will be injected into
the skin over the groin area. You may feel some stinging at the site for
a few seconds after the numbing medication has been injected.
- Once the numbing medication has taken effect, a sheath, or
introducer, will be inserted into the blood vessel. A sheath is a
plastic tube through which the catheter will be inserted into the blood
vessel and advanced to the carotid artery. If the arm is used, a small
incision (cut) will be made in the inner elbow area to expose the blood
vessel for insertion of the sheath.
- It will be very important for you to remain still during the
procedure so that the catheter placement is not disturbed and to prevent
damage to the groin (or arm) at the insertion site.
- The angioplasty catheter will be inserted through the sheath into
the blood vessel. The physician will advance the catheter through the
blood vessel into the carotid artery. A special type of x-ray, called
fluoroscopy (like an x-ray "movie"), may be used to verify the location
of the catheter inside the body.
- The catheter will be advanced up towards the heart and the carotid
arteries. Once the catheter is in place, dye will be injected through
the catheter in order to see the narrowed area(s). You may feel a brief
sensation of warmness just after the dye is injected, but this sensation
is temporary and will soon pass.
- The physician will observe the carotid arteries after the x-ray dye injection on a monitor. X-ray pictures will be taken.
- In order to protect the brain from pieces of plaque that may break
off and travel to the brain, a device called an emboli prevention device
(EPD), or cerebral protection device, will be used. One type of EPD has
a filter-like basket attached to a catheter that is positioned in the
artery so as to "catch" any clots or small debris that should break
loose from the plaque during the procedure.
- After the narrowed portion of the artery is located, the angioplasty
catheter will be advanced to that location and the balloon will be
inflated to open the artery.
- A stent may be placed in order to keep the artery open. A stent is a
tiny, cylinder-like tube made of thin metal mesh framework. The stent
will be in a collapsed position until after it is inserted, advanced up
into the aorta, and placed in the carotid artery. The stent will expand
(in a spring-like fashion), attaching to the wall of the carotid artery.
- Another x-ray picture will be taken to verify the position of the stent.
- The angioplasty catheter will be removed. However, the sheath may be
left in for several more hours. Alternatively, the physician may remove
the entire catheter system and place a special vascular closure device
at the catheter insertion site. This device helps to prevent bleeding at
the insertion site.
- You will be assisted to slide from the table onto a stretcher so that you can be taken to the recovery area.
Carotid Angioplasty and Stenting - before and after angiography
|Carotid angiography at baseline
||Carotid angiography post angioplasty and stent|