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What is balloon angioplasty and coronary bypass surgery?
Balloon angioplasty is a nonsurgical approach to alleviating the blockage in an artery
caused by plaque formation. Although mildly sedated, the patient is fully conscious during
the procedure, with most patients noting a feeling of pressure discomfort but no actual
pain. Of course, this will vary depending on the patient's tolerance level.
A small incision is made in the groin area where one of the major arteries of the body,
the femoral artery, is entered. This site is chosen because complications are less likely
to occur. A minute-sized tubing especially designed for this procedure, called a
balloon-tipped catheter, is then inserted into the artery and advanced into the heart with
the aid of a radiographic technique called fluoroscopy, which allows the surgeon to
visualize on a television monitor the progression of the catheter. Once the catheter is
positioned in the appropriate coronary artery at the site of blockage, the small balloon
is inflated and decompressed multiple times. Following each inflation maneuver,
radio-opaque dye is injected through the catheter to check the flow of blood through the
blockage. Once the obstruction has been opened enough and blood flow is sufficiently
improved, in opinion of the cardiovascular surgeon, the catheter is removed.
In most cases, the patient can go home the following day. The risk of this procedure in
modern laboratories around the country today is about 1% or less, and the chance of dying
from this procedure in a laboratory where the procedure is performed routinely is less
than 1%.
Balloon angioplasty has been done in this country since the late 1970s. By the mid
1980s, the procedure was being widely performed, and today about 400,000 balloon
angioplasties are done in the U.S. annually. Many variations of the procedure have been
employed over the past five years, including the use of cutting devices which may be used
before or after a balloon procedure, and, more recently, the use of a "stent".
Stenting in an artery is done simply by placing a wire mesh over the balloon tip of the
catheter once the blocked artery has been sufficiently opened, and balloon re-inflated and
decompressed, leaving the stent in place in the artery to help keep it open.
The problem with balloon angioplasty through the years is that there is known to be a
relatively high recurrence rate of the narrowed artery, ranging from 35% or 45% of the
patients who have had this procedure done. The use of a stent in larger arteries may
decrease the recurrence rate to less than 20% and, for that reason, stent placement at the
time of balloon dilatation has risen to as many as 25% to 30% of the case performed in
many large centers in this country. In Europe, the use of stents appears to be greater.
Coronary bypass, on the other hand, is a major surgical procedure which requires the
removal of veins from the legs to serve as substitutes for the blocked arteries in the
heart. Also, an artery which runs underneath the breast bone, called the internal mammary
artery, is often used if one of the major coronary vessels is affected by blockage.
Access to the heart is obtained by opening up the chest cavity by splitting the breast
bone. The bypass is achieved by sewing the "harvested" vein from the leg into
place at the aorta, the main artery which leads from the heart, and attaching it to the
coronary artery beyond the point of blockage. The procedure usually takes three to four
hours to perform and the length of stay in the hospital is variable. A decade ago,
patients were often hospitalized as long as 10 to 12 days following bypass surgery.
However, efforts are currently being made to shorten this time, with many patients leaving
the hospital within three to four days following bypass surgery of multiple arteries in
the heart.
This surgery is very commonly performed in the U.S. today, with numbers in the range of
250,000 to 350,000 procedures being performed. There are many variables which determine
the risk factors involved with bypass surgery, but, in the very best centers doing this
procedure, operative mortality rates may be 1% to 2%. Certainly the skills of the surgeons
have become greater, but also more knowledge has been acquired in terms of selection and
management of the patients who would benefit from this surgery, including before, during
and after this procedure. The use of bypass surgery has grown in elderly patients and this
procedure has become safer over time. However, in older patients, particularly in older
women, the risk may approach 10%.
A variation of this procedure is being investigated today in which a scope device is
used to enter the chest cavity and the procedure performed without opening the chest.
Again, this procedure is investigational at the moment, but does carry some promise for
further reducing the risk and suffering associated with this surgery.
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