To place a stent, your doctor will make a small
opening in a blood vessel in your groin (upper thigh), arm, or neck. Through
this opening, your doctor will thread a flexible, plastic tube (catheter) with
a deflated balloon on the end. A stent may be placed around the deflated
balloon. The tip of the catheter is threaded up to the narrowed artery section
or to the
aneurysm
or aortic tear site. Special
x-ray movies are taken of the tube as it is
threaded up into your blood vessel. These movies help your doctor position the
catheter.
For Arteries Narrowed by Plaque
Once the tube is in the area of the artery that
needs treatment:
Your doctor uses a special dye to help see
narrowed areas of the blood vessel.
Your doctor inflates the balloon. It pushes
against the plaque and compresses it against the artery wall. The fully
extended balloon also expands the surrounding stent, pushing it into place in
the artery.
The balloon is deflated and taken out along with
the catheter. The stent remains in your artery. Cells in your artery eventually
grow to cover the mesh of the stent and create an inner layer that resembles
what is normally seen inside a blood vessel.
Coronary Artery Stent
Placement
The illustration shows the placement
of a stent in a coronary artery with plaque buildup. The coronary artery is
located on the surface of the heart. Figure A shows the deflated balloon
catheter and closed stent inserted into the narrowed coronary artery. The
insert image on figure A shows a cross-section of the artery with the inserted
balloon catheter and closed stent. In figure B, the balloon is inflated,
expanding the stent and compressing the plaque to restore the size of the
artery. Figure C shows normal blood flow restored in the stent-widened artery.
The insert image on figure C shows a cross-section of the compressed plaque and
stent-widened artery.
The animation below shows coronary angioplasty and
stent placement. Click the "start" button to play the animation. Written and
spoken explanations are provided with each frame. Use the buttons in the lower
right corner to pause, restart, or replay the animation, or use the scroll bar
below the buttons to move through the frames.
The animation shows how a doctor
inserts a tube called a balloon catheter into a coronary artery narrowed by
plaque. The balloon catheter compresses the plaque, widens the artery, and
restores blood flow. Through the catheter, a stent is placed in the artery to
help maintain the restored blood flow.
A very narrow artery, or one that is difficult to
reach with the catheter, may require more steps to place a stent. This type of
artery usually is first expanded by inflating a small balloon. The balloon is
then removed and replaced by another larger balloon with the collapsed stent
around it. At this point, your doctor can follow the standard practice of
compressing the plaque and placing the stent.
When
angioplasty
and stent placement are performed on carotid arteries, a special filter device
is used. The filter helps keep blood clots and loose pieces of plaque from
passing into the bloodstream and brain during the procedure.
For Aortic Aneurysms
Placing a stent to treat an aneurysm in an artery is
slightly different than treating an artery narrowed by plaque. The stent used
to treat an aneurysm is made out of pleated fabric, often with one or more tiny
hooks.
Once the catheter is positioned at the aneurysm
site, the stent is threaded through the tube to the area that needs treatment.
Then, your doctor places a balloon inside the stent. The balloon is inflated to
expand the stent and have it fit tight against the artery wall. The hooks on
the stent latch on to the artery wall to anchor the stent. Your doctor then
removes the balloon and catheter, leaving the fabric stent behind.
The stent creates a new inner lining for that
portion of the artery. Cells in the artery eventually grow to cover the fabric
and create an inner layer that resembles whats normally seen inside a
blood vessel.