Heart bypass surgery is one of the most common types of heart surgery. If one of the arteries supplying blood to your heart has become narrow or blocked, your heart can’t get enough oxygen-rich blood. This leads to chest pain (angina) or even a heart attack in severe cases. If the size or location of the narrowed areas means an angioplasty and stent is not possible, bypass surgery is the main treatment.
Surgeons use a piece of blood vessel taken from the leg, arm or chest to make a “bypass” for a narrowed section of one or more coronary arteries supplying the heart.
For the past 25 years, BHF Professor Gianni Angelini and his team at the Bristol Heart Institute have been working on a new way of doing bypass surgery.
Reducing the risks of bypass surgery
Conventional bypass surgery involves stopping the heart beating, so that the surgeon can operate on a heart that isn’t moving and full of blood.
The patient’s blood is diverted to a bypass pump (also called a heart-lung machine), which mixes the blood with oxygen before pumping it around the body, effectively taking over the functions of the lungs and heart. After the grafts have been placed, the heart is restarted, and the pump is disconnected.
But stopping the heart beating and diverting blood supply into a machine is a traumatic process for the body and, although bypass surgery is potentially life-saving, there can be serious post-operative complications, including damage to the heart muscle, abnormal heart rhythms, and in severe cases, stroke and kidney damage. BHF Professor Gianni Angelini and his team have pioneered a technique to keep the heart beating during bypass surgery, to making the operation less ‘shocking’ to the body.
Stabilising the heart
There are several hurdles to overcome to make "beating heart” surgery possible. One is a way to stop the specific section of the heart the surgeon is operating on from moving. The idea of using a stabiliser device came to Professor Angelini in 1996. He came up with his own design and devoted three years to its development. It was made with stainless steel and cost about £800, but could be reused hundreds of times. Although stabilisers are now commercially available and sold by many medical manufacturers, prototypes like Professor Angelini’s stabiliser helped paved the way for the sophisticated designs used today.
Assessing beating heart surgery
When any new surgical technique is developed, it is important to carry out research to show that it is as safe as - or better than - established methods. With funding from the BHF from 1997 to 2005, Professor Angelini’s team conducted two trials comparing the off-pump technique with the standard technique. Patients who had off-pump surgery appeared to suffer less damage to their heart muscle, experienced less bleeding and need for transfusion, and had fewer episodes of heart rhythm disturbance immediately after surgery. The research suggested they may also be less likely to develop certain serious complications after surgery, such as a stroke. Their stay in hospital whilst recovering was also usually shorter.
Since these early trials, there have been several larger studies conducted across different hospitals comparing the two techniques, confirming the short-term benefits. There are some drawbacks, in particular the fact that off-pump surgery is more difficult to perform and if emergency surgery is required, there may not be ready access to a surgeon with the training required. But BHF-funded research has shown that, when performed by experienced surgeons in centres with the right infrastructure, off-pump surgery is a safe alternative to conventional surgery, both for higher-risk and lower-risk patients, and it is associated with reduced complications both in the short and long term.
An increasingly established practice
The pros and cons of performing off-pump bypass surgery are still fiercely debated by cardiac surgeons. Currently, off-pump bypass surgery is still a specialised practice. Professor Angelini’s research in this area across three decades demonstrates how long it takes to first improve a surgical technique and then to carry out the research to show that it really is an improvement.
Now with more surgeons specifically trained to perform the technique and with technological advances, such as robot-assisted surgery, this procedure has the potential to be more widely adopted, thanks to the strong foundations laid by innovative surgeons like Professor Angelini.
First published 30th March 2022