CABG is a heart surgery procedure in which one or more blocked coronary arteries are bypassed by a blood vessel graft to restore normal blood flow to the heart. These grafts usually come from the patient's own arteries and veins located in the chest (thoracic), leg (saphenous) or arm (radial). The graft goes around the blocked artery (or arteries) to create new pathways for oxygen-rich blood to flow to the heart.

The goals of the procedure are to relieve symptoms of coronary artery disease (including angina), enable the patient to resume a normal lifestyle and to lower the risk of a heart attack or other heart problems.

Types of Bypass Surgery

• Off Pump Bypass surgery( Beating Heart bypass surgery) : This is the most commonly used technique at our institution and in this technique the heart is beating normally and a small portion of the heart is stopped with the help of vacuum stabilizers to enable the surgeon do the bypass graft. The technique is of advantage in patients with bad lungs or other reasons where use of the heart lung machine is contraindicated.
• On pump Bypass surgery: In this technique the heart is placed on the heart lung machine. The machine consists of a pump and an oxygenator that acts as our lung. The blood is diverted out of the heart to the machine giving the surgeon a blood free operating field. The downside is that in some patients it can cause significant inflammatory response and also predispose more to strokes. It is also not very lung friendly hence patients with poor lung function like long term smokers or asthmatics may not tolerate it well.
• Minimally invasive bypass surgery: The days of long incisions are long gone. Now one can do bypass surgery through this technique also called MINI BYPASS Surgery, the length of the incision is 8-10cm and the chest bone is divided partially. Using a vacumm stabilizer on a beating heart one can perform multivessel bypass procedure. The advantages are low risk of infections, less pain and faster recovery.
• Minimally invasive direct coronary artery bypass (MIDCAB): Done through a lateral thoracotomy( incision through the rib spaces) applied to do a single vessel bypass. This is used only for left internal mammary artery(LIMA) to the left anterior descending artery(LAD) graft. The length of the incision is 6-8cm.
• Totally endoscopic bypass surgery: Done with the use of the Robot. This is new technology and is currently in its early stages with time it will be more used and the long term results will be available for comparison with standard techniques.

Graft Preparation

There are several types of bypass grafts that can be used in cardiac bypass surgery. The surgeon decides which graft(s) to use, depending on the location of the blockage, the amount of the blockage and the size of the patient's coronary arteries.

Internal mammary arteries [also called IMA grafts or internal thoracic arteries (ITA)] are the most common bypass grafts used, as they have shown the best long-term results. In most cases, these arteries can be kept intact at their origin because they have their own oxygen-rich blood supply, and then sewn to the coronary artery below the site of the blockage. Over the last decade, most patients received at least one internal mammary artery graft. The scientific data shows that the life expectancy of this graft is approximately 20+ years and when two of them are used the freedom from reoperation in 20 years is 98%.

The radial (arm) artery is another common type of arterial graft. There are two arteries in the arm, the ulnar and radial arteries. Most people receive blood to their arm from the ulnar artery and will not have any side effects if the radial artery is used. Careful preoperative and intraoperative tests determine if the radial artery can be used. If the radial artery is used as the graft, the patient may be required to take a calcium channel blocker medication for several months after surgery. This medication helps keep the artery open. Some people report numbness in the wrist after surgery. However, long-term sensory loss or numbness is uncommon.

The gastroepiploic artery to the stomach and the inferior epigastric artery to the abdominal wall are less commonly used for grafting.

Saphenous veins can be used as bypass grafts. Minimally invasive saphenous vein removal does not require a long incision. One to two incisions are made at the knee and a small incision is made at the groin. This results in less scarring and a faster recovery. Your surgeon will decide if this method cardiac bypass surgery is a good option for you.

Special Note: Arterial grafts are known to have longer patency rates, the internal mammary arteries have shown a significant freedom from reoperation in a study from the Cleveland clinic. The recent advent of statins and antiplatelet agents have increased the patency of vein grafts.

Some patients also are candidates for surgery using new endoscopic and robotic techniques, allowing surgeons to perform bypass surgery in a closed chest, beating-heart environment through small keyhole incisions.

Recovery

The entire surgical procedure takes 3-4 hours. The patient is shifted to intensive care unit and is there for a period of twenty four hours. The next day he can get out of bed and walk. Once he is able to do this comfortable he is shifted to the ward and here he stays for a period of 4-5 days. Full recovery from coronary artery bypass graft surgery takes around two months. Most patients are able to drive in about eight to ten weeks after surgery. Your doctor will provide specific guidelines for your recovery and return to work, including specific instructions on activity and how to care for your incision and general health after the surgery.

Coronary artery bypass graft surgery reduces the risk of major adverse cardiac events and relieves angina well but does not prevent coronary artery disease from recurring, therefore lifestyle changes and prescribed medications are strongly recommended to reduce this risk.

Coronary artery bypass surgery is widely performed in India. It is estimated that more than 800,000 coronary artery bypass graft surgeries are performed worldwide every year.