Bypass Surgery Procedure
The surgeon or an assistant surgeon removes the graft from legs or hands, ensuring the other ends are ligated properly. He then cleans the unwanted fat and other tissues attached to the graft. Injects saline to ensure that all branches are properly ligated or clipped. Nowadays saphenous vein can be harvested with minimal incision to avoid scarring and delay in healing.
Meanwhile, the chest layers are cut open right in the middle almost on top of the sternum. When the sternum is reached, the bone is sawed and the ribcage is retracted to expose the heart. The patient is connected to a heart lung machine by diverting blood from the systemic circulation through sterile plastic tubes.
The blood is oxygenized and filtered in the machine and sent back to the aorta thereby maintaining oxygen and nutrient supply to other vital organs. When the heart stops working, the surgeon identifies the block, makes incision (small cut) below the block. He then sutures the graft to that incision. Then the top end of the graft is sutured to the aorta. The left internal mammary artery that comes as a branch from aorta is left connected to its origin, however the distal or far end of the artery is divided for connection to the diseased coronary artery.
When all the grafts are in place and sutured, the heart is allowed to fill with blood and the heart lung machine is slowly weaned off. The surgeons make sure that there are no leaks in the connection between the graft and the aorta. Once the heart regains its function the pacing wires and drainage tubes are placed in the chest cavity to drain any fluid that normally collects after the procedure. The ribs are usually brought together and closed together with sternal wires and the rest of the muscles are closed in layers. The graft-harvested area is also sutured or closed in layers.
Following the surgery the chest wound is cleaned of the blood marks and dressed. The leg wound is dressed and bandaged with pressure to prevent swelling or limb edema.
Throughout the procedure an anesthesiologist will monitor the blood pressure, oxygen saturation and body temperature. Few blood tests may be repeated in intervals, especially when the patient is connected to the bypass machine.
Off-Pump Coronary Artery Bypass (OPCAB) Surgery - The same procedure can be performed without the use of the heart lung machine. It is often called as OPCAB or Off-Pump coronary artery bypass. This procedure can be performed when the heart is still beating.
Exposure of the heart is done by cutting the sternum open. Then a stabilizing device is used to hold and stabilize pertinent regions of the myocardium or heart muscle. Beating heart has to be handled very carefully, hence the lesions present on the front or anterior side is easier to graft as opposed to the ones on the lateral or posterior sides. Similar restrictions can be found in minimally invasive procedure, where the incision is made on the left side of the chest. A part of the ribcage is removed making the anterior part of the heart accessible. Patients with single vessel disease, who need one or two grafts, can be opted for OPCAB procedures.