Coronary angioplasty is a non-surgical procedure used to widen coronary arteries with cholesterol plaques. It can also be performed as an emergency treatment for heart attack (myocardial infarction).
The first part of the procedure is to localize the site of blockage (Fig. 1). This part is called cardiac catheterization and can be performed without subsequent angioplasty, i.e. just for diagnostic purposes.
Below is a narrated animation about myocardial infarction, cardiac catheterization and coronary angioplasty. Click here to license this video and/or other cardiovascular related videos on Alila Medical Media website.
A catheter (guiding catheter) is inserted through the femoral artery at the groin, or less commonly, through the radial artery in the arm (Fig. 1 and 2) and threaded all the way to the aorta. The tip of the catheter is placed at the beginning of the coronary artery to be investigated (it does not go inside the artery). A radio-opaque dye is injected through the catheter into the coronary artery. This enables real-time visualization of the artery using X-ray imaging. A narrowed part of an artery would appear as a bottle neck on an x-ray image (Fig.1).
Click here to see an animation of cardiac catheterization on Alila Medical Media website where the video is also available for licensing.
Fig. 1: Cardiac catheterization procedure for diagnosis of blocked site. Click on image to see a larger version on Alila Medical Media website where the image is also available for licensing.
After the location of stenosis (narrowed artery) is identified, angioplasty can begin. A thin guidewire with radio-opaque tip is inserted inside the guiding catheter and threaded past it into the location of plaque. Reminder : the guiding catheter stops at the start of coronary artery, but the guidewire would go further into it and to the location of blockage. An angioplasty catheter (a catheter with deflated balloon) is then inserted in such a way that the guidewire now is inside of it. The balloon is pushed to the location of blockage where it would be inflated and thus crushing the plaque (see Fig. 2 and 3). At the end of procedure, the balloon is again deflated and removed together with all catheters and guidewire.
Click here to see an animation of balloon angioplasty on Alila Medical Media website where the video is also available for licensing.
Fig. 2: Coronary angioplasty procedure. Click on image to see a larger version on Alila Medical Media website where the image is also available for licensing.
Fig. 3: Balloon angioplasty procedure. The guidewire is the thin line that goes past the plaque. The guiding catheter is (of course) NOT on this picture as it stays outside of the coronary artery. Click on image to see a larger version on Alila Medical Media website where the image is also available for licensing.
In some cases, a stent is inserted together with the balloon (Fig. 4), inflated and left on place of the plaque to keep the artery open permanently. The stent can be bare-metal (the original version) or drug-eluting (newer versions). Bare-metal stents simply provide a mechanical support. Drug-eluting stents are coated with various drugs that are released over time and act to prevent tissue growth at the site and/or modulate inflammatory response. The benefit of using stents is still debatable.
Fig. 4: Stent angioplasty procedure. Click on image to see a larger version on Alila Medical Media website where the image is also available for licensing.
Click here to see an animation of stent angioplasty on Alila Medical Media website where the video is also available for licensing.
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