OUR TREATMENTS

Cardiac Surgery

CABG + CPB

In coronary heart disease, the arteries become blocked with atheroma. This decreases the blood flow to the heart, and angina or a heart attack may ensue. Coronary artery bypass grafts or CABG is a procedure carried out to improve blood flow to the heart by using healthy blood vessels transferring and grafting them to the hearts blood supply system.

The left side of the heart is responsible for pumping blood, oxygen and nutrients around the body. Consequently, it uses a lot of oxygen as fuel in this process. If an artery blocks on the left side, it is a serious problem, as the pumping mechanism will not be as effective as it should be. For the majority of patients undergoing grafting, an artery is used from another part of the body, commonly the saphenous vein in the legs or the left internal mammary artery. This is found underneath the chest wall. This graft is generally placed in one of the arteries called the left anterior descending artery. This artery is extremely important for the left ventricle; using the internal mammary artery at this point confers a greater chance of the graft remaining patent.

This procedure is carried out under general anaesthetic. The surgeon makes an incision down the middle of the chest (sternotomy) in order to gain access to the heart and lungs. In order for the grafts to be adequately attached to the arteries, the heart is stopped (a process called cardioplegia) and the body’s blood and circulation is transferred to a cardio-pulmonary bypass machine. This specialised equipment takes over the role of the heart whilst the surgeon attaches the grafts. At the end of the operation, the heart is restarted again.

The procedure can take anything from 3-6 hours, depending on the severity of heart disease and the number of grafts required. Patients are routinely transferred to the intensive care unit to recover following this procedure.

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Off Pump Coronary Artery Bypass Graft

Off Pump Coronary Artery Bypass Graft differs from CABG in that a cardiopulmonary bypass machine is not used to oxygenate and pump blood around the body. When the heart is accessed using a sternotomy (an vertical incision down the middle of the chest), depending on the severity and difficulty in accessing the blocked arteries, the surgeon may choose to keep the heart beating as opposed to using a heart lung bypass machine. This is called “beating heart surgery”. As the name suggests, the heart is allowed to beat during surgery, and only a small area of it is immobilised by a special suction device.

Generally, patients undergoing beating heart surgery have a quicker recovery and spend less time in hospital than those who have been on a cardio-pulmonary bypass machine. This is because of the physiological insult to the body on having the blood passed through an external circuit (a bypass machine) and back into the body.

Because this technique can only be used for treating one or two grafts, it is not an option open to all patients unfortunately. The Wellington Hospital is proud to be able to provide this procedure with the aid of our highly specialised cardiac surgeons and appropriate state of the art equipment.

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Valve replacement and repair

For most people suffering from valve disease, the first step in treating it is with medication. This is because many of the new drugs used to treat heart failure and valve disease are very effective. However, as the disease progresses, it is likely that valve surgery is required. There are 2 basic forms of valve surgery:

  • Valve repair
  • Valve replacement

Valve repair is more likely to be used for a damaged mitral valve. The mitral valve regulates the forward flow of blood from the left atria into the left ventricle. The aortic valve can also be repaired, but it is far more likely to be replaced with either a mechanical valve or a tissue valve. Modern mechanical valves are manufactured from carbon fibre. They are extremely strong as they have to be able to withstand the internal pressures placed on them by the beating heart. Because mechanical valves are not made from human tissue, the blood flow over these valves has a greater propensity to clot; therefore life long anticoagulation is required. If a tissue valve has been used, it is unlikely that anticoagulation will be required after 2-4 weeks following surgery.

In order for the heart to be exposed, an incision is made down the middle of the chest. The heart is then stopped and the circulating blood is pumped through a cardiopulmonary bypass machine. This machine takes over the function of the heart and lungs when the heart has been stopped. The heart valve can then be exposed, removed and a new artificial valve placed in position. Once the heart has been closed again, the heart is restarted and the chest cavity can then be closed. Operations of this kind will require intensive care support generally for 24-48 hours in routine cases.

Mechanical valves are more robust than tissue valves. Although they require the use of anticoagulants for life, they are designed to last a lifetime. Tissue valves, depending on the patients post operative lifestyle will generally need changing in 10-15 years.

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MIDCAB

Recent technological advances in cardiac surgery are starting to have an impact on the way in which cardiac surgery is carried out. Traditional cardiac surgery necessitates the use of a large incision down the middle of the chest. The ribs then need to be split and retracted out of the surgical field. The heart is then exposed and either stopped and the blood routed through a cardiopulmonary bypass machine, or isolated as in beating heart surgery. Minimally Invasive Direct Coronary Artery Bypass is now a viable option for some patients.

The procedure does not require as large an incision as with CABG, instead a smaller 10-12 cm incision is made over the left side of the chest. The left internal mammary artery is then harvested to use as the graft vessel. The heart is kept beating with this form of surgery but a special device isolates the portion of the heart being grafted. The graft can then be placed to bypass the diseased or occluded coronary artery.

Because this technique can only be used for treating one or two grafts, it is not an option open to all patients unfortunately. The Wellington Hospital is proud to be the only independent sector provider able to facilitate this procedure with the aid of our highly specialised cardiac surgeons and appropriate state of the art equipment.

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