What is Bypass Surgery?

Coronary Artery Bypass Grafting or CABG as it is more popularly known is probably the most commonly performed surgery the world over. A shroud of fear and ignorance seems to cover the face of this life saving procedure. Many misunderstandings have prevented a very deserving person from benefiting from what this surgery has to offer. This article aims to provide the reader with a clear view of what the surgery involves and dispel the myths.

What are coronary arteries? How does the heart get the blood it needs?

The heart is a complex muscular pump which ensures adequate blood supply to the body. The blood is supplied via arteries to the various parts of the body and carries with it the much needed oxygen and nutrients. The heart itself needs blood, which is supplied via the coronary arteries, which only mean the arteries of the heart.

This consists of the left and right coronary arteries and their branches. The left main coronary artery (LMCA) is short and divides into two branches, the left anterior descending artery (LAD) and the circumflex artery (LCx). These two along with the right coronary (RCA) artery account for the three arteries referred to in the term ‘triple vessel disease’. These three arteries divide into many many branches and supply blood to the muscle of the heart.

What is coronary artery disease? How does it affect the heart?

Coronary arteries may be affected by occlusive artherosclerotic disease, which is what is commonly referred to as coronary artery disease. Fatty substances get deposited on the wall of the arteries leading to their narrowing. One or more of the coronary arteries may then get blocked decreasing the blood supply to regions of the heart.

This causes chest pain, which your cardiologist calls Angina. A heart attack may occur in more severe cases, which damages the heart permanently decreasing its efficiency.

CABG (Coronary Bypass Surgery)

CABG is the shortened more popular name for Coronary Artery Bypass Grafting. This surgery aims to supply the starved heart muscle with more blood by passing the blockages. The blood vessels from the patient’s own body, which he can spare, are used to perform these bypasses. The internal mammary arteries supply blood to the chest wall and the breast bone. The left internal mammary artery commonly known as the LIMA is used to bypass the LAD, which is the most important artery of the heart. The best results have been observed with use of this artery, which makes this the surgeon’s favourite. The veins from the legs called the saphenous veins and the radial artery from the arm are also used. The surgeon studies the coronary arteries and tailors his plan of revascularization to suit the needs of the individual patient. Once the surgeon joins up or anastamoses the grafts, blood flows through them into the blocked arteries beyond the blocks thus bypassing them. The blocks are not removed but are bypassed, hence the name bypass surgery!

Conventional CABG

Coronary artery bypass grafting is the surgical procedure in which the grafts are connected up to the blocked arteries. Conventional CABG is when cardiopulmonary bypass with the heart-lung machine is used to perform the operation. The heart-lung machine allows the heart’s beating to be stopped, so the surgeon can operate on a surface, which is blood-free and still. The heart-lung machine maintains life despite the lack of a heartbeat, removing carbon dioxide from the blood and replacing it with oxygen before pumping it around the body.

Beating Heart Bypass Surgery (Off-pump Surgery)

Off-pump or beating heart bypass surgery allows surgeons to perform surgery on the heart while it is still beating. A medication may be given to slow the heart during surgery, but the heart keeps beating during the procedure. This type of surgery may be an option for patients with single-vessel disease.

During off-pump or beating heart surgery, the heart-lung machine is not used. The surgeon uses advanced operating equipment to stabilize portions of the heart and bypass the blocked artery in a highly controlled operative environment. Meanwhile, the rest of the heart keeps pumping and circulating blood to the body.

This new approach is being followed in our hospital for the past 6 years. Over 5000 cases have been done this way and the post operative recovery is found to be smoother with much fewer complications.

Minimum Invasive Cardiac Surgery

Improving patient comfort by reducing pain is one of the concerns of a cardiac surgeon. Making the procedure less invasive is one of the ways in which we aim to achieve this. Minimally invasive surgery is performed through a small incision, often using specialized surgical instruments. The incision is about 3 – 4 inches instead of the 6-8 inch incision required for traditional surgery.

Benefits of Minimally Invasive Surgery

The benefits of minimally invasive surgery include:

• A smaller incision
• A smaller scar
• Reduced risk of infection
• Less bleeding
• Less pain and trauma
• Decreased length of stay in hospital after the procedure: the average stay is about three days after minimally invasive surgery, while the average stay after traditional heart surgery is five days.
• Decreased recovery time: the average recovery time after minimally invasive surgery is 2 – 4 weeks; while the average recovery time after traditional surgery is 6 – 8 weeks.

Types of minimally invasive cardiovascular surgeries include:

• Valve surgery
• Coronary artery bypass graft (CABG) surgery
• Epicardial lead placement: placement of leads for biventricular pacemakers (cardiac resynchronization therapy)
• Atrial fibrillation

Minimally invasive direct coronary artery bypass graft (MID CABG) surgery is an option for some patients who require a left internal mammary artery bypass graft to the left anterior descending artery. A small, 2 – 3 inch incision is made in the chest wall between the ribs, whereas the incision made during traditional CABG surgery is about 6 – 8 inches long and is made down the center of the sternum (breastbone). Saphenous (leg) vein harvest may also be performed using small incisions.

Keyhole Approaches

For some surgical procedures, an endoscopic or “keyhole” approach may be performed. This approach may also be referred to as port access surgery or video-assisted surgery. The port access surgery technique allows surgeons to use one to four small (5 – 10 mm) incisions or “ports” in the chest wall between the ribs. An endoscope or thoracoscope (thin video instrument that has a small camera at the tip) and surgical instruments are placed through the incisions. The scope transmits a picture of the internal organs on a video monitor so the surgeon can get a closer view of the surgical area while performing the procedure.

Types of surgeries that may be performed using the innovative port-access or “keyhole” approach include:

• CABG surgery
• Valve surgery
• Bi-ventricular pacemaker lead placement on the surface of the left ventricle
• Minimally invasive surgery for atrial fibrillation: Specialized instruments are used to create new pathways for the electrical impulses that trigger the heartbeat. Unlike traditional surgery for atrial fibrillation, there is no large chest wall incision, and the heart is not stopped during the procedure.

Some types of thoracic surgery: Video-assisted thoracoscopy (VATS), also called the thoracoscopy of pleuroscopy, is a minimally invasive surgical technique that may be used during some types of thoraicic surgeries, such as partial resection of the lung, lung biopsy, lobectomy, drainage of pleural effusions, or pericardial and mediastinal biopsies.

Coronary surgery is a very dynamic field and many changes keep the medical personnel on their feet. Robotics is one such. Robotic surgery makes use of highly specialized robots to execute many steps in the surgical procedure. Hybrid coronary bypass is a relatively new procedure and an alternative to traditional bypass surgery that is defined by the performance of coronary bypass surgery and coronary stenting during the same operation. This can be combined with minimally invasive procedures very effectively.