How Are Stents Placed?

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 what’s normally seen inside a blood vessel.