Cardiac catheterization for stenotic (narrowed) blood vessels

What is cardiac catheterization for stenotic blood vessels?

Cardiac catheterization is used to treat carotid artery stenosis. This type of procedure involves the use of an inflatable balloon catheter in order to widen the arteries, followed by the insertion of a stent to support the blood vessels from the inside.
Also referred to as balloon angioplasty or PTCA (percutaneous transluminal coronary angioplasty), this procedure is usually carried out using a local anesthetic to numb the access site in the groin. General anesthesia is therefore not required.

When should cardiac catheterization be used to treat stenotic blood vessels?

Cardiac catheterization for coronary artery disease is suitable in:

• Patients with coronary heart disease, particularly if this cannot be controlled through medication, or when bypass surgery is either unnecessary or impossible.
• Many cases involving acute heart attack.

How can cardiac catheterization help in the treatment of stenotic blood vessels?

Cardiac catheterization is used to treat stenosis (narrowing) of the carotid arteries. Stenoses almost always develop as a result of a hardening (atherosclerosis) of the coronary arteries. Coronary artery stenosis is also referred to as coronary heart disease, and is typically a precursor to a heart attack.

The principle behind this type of intervention is that, by widening the narrowed coronary arteries, one can ensure that a sufficient amount of blood reaches the area of the heart situated beyond the area of stenosis. This is done by using an inflatable balloon catheter. In most cases, the intervention will also involve the insertion of a special wire mesh tube (stent), which supports the artery walls from the inside and can help to prevent restenosis. These stents often have a drug-eluting coating, which prevents excess tissue from building up inside the treated coronary artery, thus reducing the risk of restenosis even further.

This procedure can also be performed with tools other than inflatable balloon catheters, and may at times involve the use of a laser catheter or a diamond burr.

It is not always necessary or even advisable for patients with coronary heart disease or heart attack to be treated with cardiac catheterization. In certain cases, drug-treatment may suffice. Bypass surgery may be a better option for some patients, as it produces better results than those achievable with cardiac catheterization. However, many patients benefit from the fact that cardiac catheterization eliminates the need for open surgery.

Cardiac catheterization also offers the advantage of combining both diagnostic and treatment procedures. For instance, a catheter-based intervention starts with the injection of a contrast agent into the coronary arteries, followed by a detailed examination of the arteries using x-ray technology (coronary angiography). Stenoses identified as requiring treatment can then be removed as part of the same procedure.

What happens during cardiac catheterization for stenotic blood vessels?

A typical catheter-based intervention to treat coronary artery stenosis consists of the following steps:

• Following the application of a local anesthetic, a tiny incision is made in one of the arteries in the groin (or, less frequently, in the lower arm). Using x-ray guidance, a flexible catheter made of synthetic material is then inserted, and advanced to the heart.
• The physician injects a contrast agent into the coronary arteries, making any stenotic areas clearly visible on the x-ray monitor.
• The interventional cardiologist inserts a small balloon catheter into the narrowed coronary artery, and inflates the balloon to a pressure of 8 to 12 bar (1 bar= 0.987 atm), which is approximately ten times that of normal atmospheric pressure.
• The physician will then usually insert a stent to support the artery - the unexpanded tube-shaped wire mesh is slipped onto the balloon catheter. The catheter is then advanced into the affected coronary artery, where the balloon is inflated until the wire mesh has expanded, leaving the stent pressed into the vessel walls.
• Once the stent has been implanted, the balloon catheter is removed. A pressure bandage is applied to the groin area, and will have to remain in place for some time.