What is Bypass Surgery

Coronary Artery Bypass Grafting (CABG) is a common procedure across the world. Nevertheless, some patients choose to avoid it due to misperceptions about what it entails.

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

The heart is a complex muscle which pumps blood to the various tissues and organs of the body, ensuring the circulation of oxygen and nutrients. The heart itself receives blood via the coronary arteries. These consist of the left main coronary artery (LMCA), which separates into the left anterior descending artery (LAD) and the circumflex artery (LCX), as well as the right coronary artery(RCA). These three arteries then divide into numerous branches that supply blood to heartâ€™s muscles.

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

Coronary arteries disease (or occlusive artherosclerotic disease) occurs when fatty substances are deposited along the wall of the arteries, causing them to narrow. When one or more of the coronary arteries is blocked, the supply of blood to regions of the heart decreases. This leads to Anginas, or chest pains, which can escalate, in more serious cases, to a heart attack â€“ which can damage the heart permanently.

CABG (Coronary Bypass Surgery)

Coronary Artery Bypass Grafting (CABG) is a procedure that bypasses the blockages and supplies blood to the affected heart muscles. The patientâ€™s own blood vessels are used to perform these bypasses. The best results are often obtained by using the left internal mammary artery (LIMA) â€“ which supplies blood to the chest wall and the breast bone â€“ to bypass the LAD.

The saphenous veins (from the legs) and the radial artery (from the arm) can also be used. The surgeon plans the revascularization, based on the individual patientâ€™s needs.

Conventional CABG

Coronary artery bypass grafting involves connecting grafts to the blocked arteries. Conventional CABG involves a cardiopulmonary bypass via the heart-lung machine (which allows the heart to be stopped so that the surgeon can operate on a still, blood-free surface). The heart-lung machine temporarily works as the heart, eliminating carbon dioxide from the blood and supplying the body with oxygen.

Beating Heart Bypass Surgery (Off-pump Surgery)

This surgery can be performed on the heart while it is still beating (a medication may be used to slow down the heart), and is usually performed for patients with single-vessel disease.

The surgeon utilizes advanced operating equipment to stabilize the relevant portion of the heart; the blocked artery is bypassed within a highly controlled environment. The rest of the heart circulates blood to the rest of the body as per usual.

Beating heart surgeries typically allow for smoother post-operative recoveries, with a lower risk of complications.

Minimum Invasive Cardiac Surgery (MICAS)

MICAS (also known as MICS CABG) is a safe and complete operation that has revolutionised the way coronary surgery is performed. While conventional coronary bypass surgeries (CABG) are performed by splitting or cutting through the breastbone or sternum, this relatively novel and advanced technique allows our surgeons to approach the heart through the side of the left chest, via a small 4 cm incision.

Benefits of Minimally Invasive Surgery

A minimally invasive surgery involves a smaller incision, a smaller scar, a reduced risk of infection, less blood loss, reduced pain and trauma, and a decreased length of stay and recovery time.

Types of minimally invasive cardiovascular surgeries include valve surgery; coronary artery bypass graft (CABG) surgery; epicardial lead placement (placement of leads for biventricular pacemakers, also known as cardiac resynchronization therapy); atrial fibrillation; saphenous (leg) vein harvest; minimally invasive direct coronary artery bypass graft (MID CABG) surgery.

Keyhole Approaches

An endoscopic or â€˜keyholeâ€™ approach (also known as port access surgery or video-assisted surgery) is performed in certain cases. The port access surgery technique involves the incision of one to four small (5 - 10 mm) â€˜portsâ€™ in the chest wall, between the ribs. An endoscope or thoracoscope (a thin video instrument that has a small camera at the tip) is then placed into the incisions, transmitting a picture of the internal organs onto a video monitor for surgeon to get a closer view of the surgical area while performing the procedure.

The keyhole approach is used for CABG surgery, valve surgery, the placement of bi-ventricular pacemaker lead on the surface of the left ventricle, and minimally invasive surgery for atrial fibrillation. The latter involves creation of new pathways for the electrical impulses that trigger the heartbeat via specialized instruments.

Some examples of thoracic surgery include video-assisted thoracoscopy (VATS) which is a minimally invasive surgical technique that is used to treat thoraicic surgeries, e.g. partial resection of the lung, lung biopsy, lobectomy, drainage of pleural effusions, or pericardial and mediastinal biopsies.

The field of coronary surgery involves continuous technological developments, the latest being robotics. Robotic surgery involves the usage of highly specialized robots to execute various steps within the surgical procedure. Other developments include the hybrid coronary bypass, an alternative to traditional bypass surgery that involves performing coronary bypass surgery and coronary stenting within the same operation.