Off-Pump Coronary Artery Bypass (OPCAB)

(To read about one patient's experience with Off-Pump Coronary Artery Bypass, click here.)

An exciting new technique called "Off-Pump Coronary Artery Bypass" (OPCAB) is being performed at Bridgeport Hospital. Patients whose condition permits the use of OPCAB can recover faster, with fewer side effects, than with standard coronary artery bypass graft surgery (CABG).

Who may qualify for OPCAB? Patients who have three or fewer blocked arteries, and in whom those arteries do not lie at the back of the heart where OPCAB techniques would not be able to reach.

In standard bypass surgery, the beating heart is stopped while the surgeon does the precise and delicate stitching required to attach blood vessels to the heart. A bypass machine, or pump, circulates the patient's blood during the surgery.

In off-pump procedures, the surgery is performed while the patient's heart continues to pump, without missing a beat! Three things make off-pump bypass procedure possible.

1. The ability to position the heart so that we can reach any vessel;
2. Medications that can quiet down the beating heart; and
3. Devices to immobilize the small area of the heart where the graft is made.

In the operating room, after the opening of the patient's chest, the operating table is slowly tilted head down. Because the heart is connected to the body largely by the main blood vessels at the top, it is mobile at the bottom. So as the head is lowered, the bottom end of the heart gradually leans outward, exposing the arteries on the side of the heart.

Then the surgeon places stitches at the right and left sides of the tough sac that surrounds the heart. By slowly pulling up on the stitches, the surgeon can tilt the heart one way or the other, positioning it so as to work on the blocked vessels.

Next, to steady the small part of the heart where the surgeon will operate, a device with two rows of suction cups is positioned so one row of suction cups lay on each side of the artery. (See illustration to the right.)

Then small elastic threads are looped around the artery above and below the blocked area. Acting as clamps, they can be tightened and loosened as needed to stop the flow of blood through that artery alone. "It's like closing one lane of a multi-lane highway to fill a pothole, rather than shutting down the whole road and detouring traffic," explains Clive Robinson, MD, chief of Cardiothoracic surgery at Bridgeport Hospital. "The other lanes stay open and traffic continues to flow."

Next the surgeon prepares the heart cells to go without blood for brief moments. The surgeon uses the elastic clamps to cut off the blood supply for several minutes, then releases it. This is done two or three times—a process called "preconditioning." This helps the heart muscle get used to an interruption in blood flow during the grafting.

Then the cardiac anesthesiologist administers drugs that calm the vigor of the heartbeat and slow the heart rate. The clamps are closed and the new vessel is grafted to the blocked artery. Then the clamps are opened, letting the blood flow to the heart muscle.

In about three hours, the entire procedure is over, and the patient is recovering in the Cardiac Intensive Care Unit.

Advantages of OPCAB

The body works best when blood pulses through it. The bypass machine is necessary for certain kinds of open-heart procedures, and during off-pump procedures, The Heart Institute Operating Room always has one on stand-by in case of need. But it doesn't really pump blood—it circulates blood continuously, which is not how the body likes to work. Also, there is contact between the blood and the artificial tubing in the bypass machine All of this can cause problems with the blood's natural clotting ability, and can lead to fluid build-up in the body tissues, particularly in the brain and lungs. It takes time for the body to eliminate the excess fluid and get back to normal. If using the bypass machine can be avoided, most patients can go home in three or four days as opposed to four or five, and recovery time is much faster.

Next step, and a very important one for a full recovery: Healthy Heart Program (formerly Outpatient Cardiac Rehab)!