Coronary revascularisation surgery is a surgical procedure used to treat blockages of the blood vessels that supply blood to the heart (coronary occlusion) and improve blood flow.
How is it done?
The operation consists of creating a bridge (bypass) to skip the obstruction in the coronary artery and improve blood flow. Arteries from the thorax or veins from the leg are used for this.
It is the most invasive treatment for coronary artherosclerosis, but it also presents the best long-term results.
Why is it recommended?
Coronary arteries can be partially or completely obstructed by the accumulation of cholesterol and fat deposits, known as plaques. This process is known as atherosclerosis, and it can mean that the heart does not receive enough oxygen and nutrients.
This situation can lead to progressive deterioration of the cardiac muscle and cause diseases such as angina pectoris, or even a myocardial infarction. Coronary revascularisation surgery can improve cardiac function and reduce the risk of mortality associated with coronary disease.
In general, coronary bypass surgery is an option if the patient presents:
- Coronary disease in more than one vein (multivessel). This causes little blood flow to reach the cardiac muscle, including during light exercise and at rest. Sometimes angioplasty and inserting a stent can help but, with some types of obstructions, coronary bypass surgery may be the best option.
- Multivessel coronary disease with left ventricle dysfunction.
- Impairment of the left main coronary artery (main trunk). This artery provides the majority of the blood flow to the left ventricle.
- Having an obstruction in the artery that means angioplasty is not suitable. Angioplasty is an intervention that consists of dilating an occluded artery or vein to restore blood flow. In the majority of cases, a stent is also implanted.
- Having previously had an angioplasty or stent that was unsuccessful, or having had a stent fitted, but the artery has narrowed again (restenosis).
- Emergency situations. For example, an acute myocardial infarction (AMI), in the event that the patient does not respond to other treatments.
How do I prepare?
Before the operation, various pre-surgery tests need to be carried out: chest radiographies, blood analysis, electrocardiogram and coronary catheterisation.
Most people are admitted to hospital one day before or the morning of the surgery. Coronary revascularisation can also be performed in emergency situations.
Patients undergoing this operation should not eat or drink for six to eight hours before surgery.
The doctor carrying out the operation will explain to the patient what will happen before, after and during the procedure, and will tell them about any pain they may experience. Any questions the patient may have about the surgery can be answered at this time.
Will I be able to take my medication?
The doctor who performs the operation will give specific instructions to each patient about any restrictions on activity, changes in lifestyle and medication that are required. For example, they may recommend changing your diet, quitting smoking or taking certain medications before surgery. The treatment will depend on the condition of the patient’s coronary arteries.
What happens during the operation?
This operation requires a general anaesthetic. Most coronary bypass operations are done via an incision in the thorax, through the sternum.
To carry out the bypass, a stitch or a graft can be made in the internal mammary artery or the saphenous vein to the diseased coronary artery. One or more blood vessels are used, depending on the case.
If there is more than one obstructed artery, more grafts will be used. This is known as a double, triple or quadruple aortic coronary bypass. The number depends on the location and the severity of the diseased coronary arteries.
Furthermore, the surgery can be performed in two ways:
- On-pump: Extracorporeal circulation pump, or conventional surgery, which uses a heart-lung machine to pump blood instead of the heart.
- Off-pump: If an extracorporeal circulation machine is not used, it is known as beating heart surgery. This procedure is performed using special equipment to stabilise the heart.
There are other techniques that the surgeon can employ, such as minimally invasive surgery. In this procedure, the coronary bypass is done through a much smaller incision in the thorax, often using a robot and video images that help the area to be visualized more exactly during the operation.
At the end of the operation, the thorax is closed.
Heart operations, whether for coronary, valvular, or other diseases, require the heart to be stopped in most cases.
In order to be able to stop the heart and ensure that the rest of the body continues receiving blood and oxygen, nursing staff known as perfusionists are required to act. They use the extracorporeal circulation machine (heart-lung pump) to stop and protect the heart, as well as to maintain circulation and oxygenation to the rest of the body.
This machine has various components, and each one has a specific function. The main module is known as the pump head and performs the function of the heart and lungs, as well as cardioplegia, which is used to stop the heart. The solutions indicated for this purpose are administered to the patient, at a very low temperature.
With this treatment, the myocardium (heart muscle) is in optimal conditions to start beating again once the coronary grafts, in other words, the bypass, have been done
Other modules are used as aspirators, so that the blood lost through incisions is returned to the circulatory flow.
This whole procedure is performed under strict safety measures, which are carried out before, during and after the operation.
During the process, numerous professionals work in a coordinated way; the operating theatre nursing staff, anaesthesia nursing staff, anaesthesiologists, surgeons and perfusionists.
Once the coronary bridges have been made, the heart will once again receive blood naturally and will start to beat, after which extracorporeal circulation is deactivated. This is done progressively, so that the heart starts to pump more and more blood, while the machine pumps less and less. Once the heart is doing all the work, extracorporeal circulation can be suspended, although it will remain prepared to restart in case any complications arise.
To be able to do all this work, anticoagulants must be administered to the patient before beginning extracorporeal circulation. Once the operation is finished, the effect of the anticoagulants is neutralised with another drug so as to reduce the risk of bleeding.
Extracorporeal circulation is an extensively used, safe technique. It is used in practically all cases of heart surgery, in Catalonia, Spain, and all over the world.
How long does it last?
Coronary revascularisation surgery generally lasts between three and four hours, and requires general anaesthetic.
What happens after coronary revascularisation surgery?
After the operation, patients are transferred to the Intensive Care Unit (ICU) and, a couple of days later, as soon as their condition is stable, they are transferred to a ward. They are usually discharged from hospital approximately 7-10 days after surgery. Recovery can last six to eight weeks, but in some cases it can take up to three months to fully recover.
Symptoms such as chest pain and difficulty breathing generally disappear or improve following revascularisation surgery.
Even with good surgical results, lifestyle changes are a fundamental part of post-operative treatment. Patients are advised to avoid lifting heavy objects and other activities requiring physical effort until a healthcare professional indicates this is safe.
The medication usually prescribed after revascularisation tend to focus on reducing blood cholesterol, reducing the risk of developing clots and aiding heart function.
What are the possible complications?
There can be complications associated with coronary revascularisation surgery, both during and after the procedure:
- Heart rhythm disorders (arrhythmias)
- Infection of the surgical wound
- Disturbances to consciousness (generally temporary)
- Renal disturbances
- Acute myocardial infarction
This risk of these complications is low, although it depends on the patient’s condition prior to surgery.
There is a greater risk of complications if the operation is carried out as an emergency, or if the patient has other medical conditions such as lung disease, kidney disease, diabetes or peripheral artery disease.