Making the Diagnosis
Coronary artery bypass surgery is an open-heart procedure. The person
is placed under general anesthetic. The surgeon will begin the operation by
making an incision down the center of the chest, then dividing and separating
the breastbone (sternum). Tubes are then attached to the heart and connected
to a heart-lung machine that keeps the blood supplied with oxygen. Blood will
be pumped from the heart to the machine and back to the body to be circulated
again. Blood pressure, temperature, and breathing will all be regulated.
Once the heart-lung machine has taken over for the heart, the surgeon will
clamp the aorta (a major artery taking blood from the heart to the rest
of the body). He or she will then graft or sew a vein or artery taken from
another part of the body onto the blocked coronary artery. The grafted veins
or arteries join the aorta to the coronary artery, bypassing the blocked part
of the coronary artery to bring oxygen-rich blood to the heart. The vein used
for the graft is usually taken from the leg (the saphenous vein).
Surgeons will often use at least one artery as a graft. This is often an internal
mammary artery taken from the left or right side of the chest wall beneath the
breastbone. The mammary artery is sewn directly on to the blocked coronary artery.
In some cases, the mammary artery from the other side of the chest or an artery
from the forearm may also be used. Both the veins and arteries used were nonessential
in their original location, and their removal is not harmful.
Once the grafting is finished, the person is taken off the heart-lung machine.
The heart and lungs will take over again, and the surgeon will rejoin the breastbone
with stainless steel wires. As few as one and as many as five or six bypasses
may be performed in a single operation.
New techniques of bypass surgery may be used in some cases. The most
common method is the "beating-heart" technique. This does not use
the heart-lung machine setup but still needs to be done through the incision
in the middle of the chest. Bypasses are sewn directly onto the heart without
stopping the heart. This reduces the risk of the complications from the heart-lung
machine.
An average operation lasts from three to six hours. Patients are then
monitored in an intensive care unit for at least 24 hours and may be kept sedated
for their comfort. Most patients can eat solid foods after a day or two and
leave the hospital in about five to seven days. The stitches are removed about
a week after the operation. The doctor will often recommend an exercise program
to help the healing process and to ease the return to previous levels of activity
and return to work.
After surgery, all patients will need to continue taking medications that
decrease the work of the heart and reduce the risk of future heart attacks.
The medications usually prescribed are aspirin* to prevent
blood clots, beta-blockers, cholesterol-lowering medications such as the statins,
and ACE inhibitors (medications that control blood pressure). Artery
grafts rarely go on to develop coronary artery disease. More than 80% still
work ten years after the surgery. Vein grafts more often become obstructed.
After five years, one quarter of any vein grafts may be clogged.
*All medications have both common (generic) and brand names. The brand name
is what a specific manufacturer calls the product (e.g., Tylenol®).
The common name is the medical name for the medication (e.g., acetaminophen).
A medication may have many brand names, but only one common name. This article
lists medications by their common names. For more information on brand names,
speak with your doctor or pharmacist.