Coronary Artery Bypass Surgery (CABG)
What
does "bypass surgery" mean?
Bypass surgery
can be performed on any artery in the body, but most often involves the
coronary arteries (the arteries that supply blood to the heart muscle
itself). During bypass surgery, a graft vein or artery is taken from a
healthy blood vessel in the body. The graft is then surgically attached
above and below an obstructed or poorly functioning artery. After surgery,
the blood will flow thru the graft vessel, avoid or "bypass" the
blocked vessel, and provide oxygen and nutrients necessary for survival to
the area of tissue beyond the blockage.
Why
is the doctor performing this surgery?
To bypass,
or go around, the obstruction caused by a coronary (heart) artery filled
with a clot or with plaque (atherosclerosis). If the obstruction is not
bypassed, the heart muscle beyond the obstruction is denied oxygen and
nutrients leading to heart damage (heart attack or chest pain).
What
is the surgery?
There are
two types of Coronary Artery Bypass Surgeries (CABGs) routinely performed:
·
On Pump - On Pump CABG is also known as
"Traditional Bypass Surgery". The pumping and oxygenation
function of the heart is taken over by a heart-lung machine during the
surgery, and medications are given that briefly paralyze the heart
(cardioplegia). This way, the heart is completely at rest while the surgeon
performs the bypass surgery.
·
Off Pump/Beating Heart - Off Pump CABG is also known as
"Beating Heart Bypass Surgery" and is another method of bypass
surgery. A heart-lung machine is not used, and the heart is not stopped
with medications. Instead, the heart continues to perform its pumping and
oxygenation functions while the surgeon works. The surgeon stabilizes just
the portion of the heart where the bypass is needed, while the remainder of
the heart continues to function normally. According to the Journal of the
American Heart Association, off-pump bypass, in the appropriate patients,
is as safe and effective as standard on-pump coronary bypass surgery, and
many healthcare professionals, including our surgeons believe it may reduce
the risk of stroke, bleeding and renal failure. Off-pump bypass is not for
everyone, and there is no long-term data available about
outcomes…yet. However, it is a highly effective surgical option which
you can discuss with your doctor.
There are
four sources used during bypass surgery for the healthy graft blood vessel:
·
Endoscopic Vein Harvesting - The saphenous vein
in the leg is the most common vein used as a bypass graft. Traditionally,
the saphenous vein was obtained via a long incision in the leg, from groin
to ankle. Contrary to popular perception, this usually presents the highest
degree of post-procedural pain. This new endoscopic technique requires only
two or three 1-inch long incisions in the leg. An endoscope connected to a
video camera is then inserted into the smaller incisions and the saphenous
vein is removed with far less scarring and trauma. This technique is only
available in select centers throughout the US.
·
Arterial Bypass - There are several arteries that can be
used as grafts for bypass surgery, but the most common is the left internal
mammary artery (LIMA).
The right internal mammary artery (RIMA) may also be used as a graft. These
arteries are accessed thru the same chest incision used to access the
heart. Occasionally, the radial (in the arm) or the gastroepiploic (near
the stomach) arteries may be used, each accessed thru separate incisions.
·
Sutureless Anastomic Device - On occasion,
surgeons use a sutureless device, which can be used for the part of a vein
graft that is attached to the aorta. The saphenous vein is loaded onto a
device that is inserted into a small hole the surgeon has cut in the
patient's aorta. He or she then pushes a button, releasing a tiny web of
wires, which unfold to form a star-shaped rivet. Your doctor can determine
if this is an option for you.
·
Donor Saphenous Vein: This is a vein that has been
cryopreserved and stored in a tissue bank. It is blood type specific for
the patient.
Where
is the surgery performed?
Both On-Pump
and Off-Pump/Beating Heart surgeries are performed in the Operating Room
(OR), and under general anesthesia.
How
long does this surgery take?
The length
of time surgery takes will vary based on the number of vessels being
bypassed, the graft location, On-Pump vs. Off-Pump/Beating Heart procedure,
the patient's associated medical problems, etc, but usually an On-Pump or
Off-Pump/Beating Heart surgery will take between 3-6 hours.
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