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.
- 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.