What is Coronary Artery Bypass Grafting?
Coronary artery bypass grafting (CABG) is a surgical procedure that aims to reduce the mortality rate and improve quality of life for patients with coronary artery disease.
Coronary artery disease occurs when the blood vessels that supply oxygen rich blood to the heart muscle narrow due to a build-up of fatty material on their walls.
Coronary artery bypass grafting resolves this predicament by bypassing the blocked portion of the coronary artery with a piece of a healthy blood vessel collected from the other part of the body.
The healthy blood vessel piece is harvested from one of these sites:
Left internal thoracic artery (LITA)
Right internal thoracic artery (RITA)
Inferior epigastric artery
Right gastroepiploic artery
The traditional technique involves making a large incision in the chest and temporarily stopping the heart. The chest is opened by cutting the sternum in half lengthwise and then spread apart. Once the heart is exposed, tubes are inserted into the heart and then linked to a heart-lung bypass machine. The heart is stopped and the bypass machine pumps blood throughout the body in its stead (this is called a cardio-pulmonary bypass).
This open heart technique is done a regular basis and preferred in many situations. However, less invasive techniques have been developed and are slowly being implemented for their numerous benefits.
The Minimally Invasive Direct Coronary Artery Bypass Technique
Minimally invasive direct coronary artery bypass (MIDCAB) is an innovative coronary bypass technique that is designed to achieve the same results as the classic procedure, but in a less invasive manner.
Unlike conventional techniques, which use of a large incision (6”-8”) and cardiopulmonary bypass, MIDCAB is performed through a 3"-5" incision placed between the ribs or two to three small 1”-2” incisions. It is also performed while the heart is beating.
The MIDCAB technique has shown excellent results so far, the procedural success estimated at 98%. The procedure has also been shown to provide numerous advantages over the conventional surgery:
Better ability to cough and breathe deeply
Discharge from the hospital in 2-3 days (5-10 days for traditional techniques)
Reduced risk rate of complications such as renal failure, stroke, infections
Return to normal activities within 2 weeks of surgery (6-8 weeks for traditional techniques)
The Totally Endoscopic Coronary Artery Bypass Grafting Technique
Endoscopic Coronary artery bypass grafting employs the use of robotic devices to treat coronary artery disease without the need of large incisions or stopping the heart.
The first step of the technique involves deflating the lung. Then, 3 small incisions are made between the ribs. A robotic arm with 2 arms carrying surgical tools and an endoscope is introduced in the incisions. The arms are controlled by a specialized surgeon in order to harvest suitable blood vessel and then attach the grafts across the affected coronary artery.
This technique aims to reduce the rate of post-surgery complications, duration of hospital stay, surgery cost and improve overall patient quality of life.
Off-pump Coronary Artery Bypass Grafting Technique
Off-pump CABG is a variation of the traditional technique. The difference is mainly that traditional surgery is done while the heart is still beating, cutting the need of a bypass machine. The procedure was introduced due to the need to minimize surgery costs and the adverse effects of artificial blood pumping in the elderly population that underwent the procedure.
A stabilizer is used during the procedure to minimize the movement in the area of the heart that is to be bypassed. The technique also requires the use of warming blankets, different operating positions and IV fluid infusions so as to maintain adequate heart rate, blood pressure and body heat.
The procedure was postulated to reduce mortality rate, stroke and infarctions. However, systematic reviews of trial results did not show any significant benefits of this technique compared to traditional coronary artery bypass grafting.