NEW YORK – Researchers have developed a tiny balloon that may be able to help doctors identify heart surgery patients who may be at risk of developing fatal complications.
The tubular balloon, which is a few centimeters long, is placed in the chest at the end of bypass surgery and other types of major heart procedures.
Surgeons insert a thin wire through the chest with a deflated balloon at the end. Once it is placed inside the pericardial sac (the fibrous sac in which the heart sits), the balloon is inflated.
The other end of the wire is attached to a monitor that measures changes in pressure on the balloon. The idea is that monitoring this pressure for several days while the patient recovers in the hospital will provide an early warning of a potentially fatal condition called cardiac tamponade.
This occurs when the pericardial sac fills with blood or fluid leaking from blood vessels damaged during heart surgery.
When the sac fills with fluid, it puts pressure on the heart, stopping it from beating properly and greatly reducing blood flow to other vital organs.
The condition usually develops within 48 hours of a major heart procedure. It is considered a medical emergency because if not caught quickly, it can lead to fatal cardiac arrest.
Although a rare condition, it is responsible for 30% of deaths due to complications from heart surgery.
The experimental balloon device, developed by cardiac surgeon Hazem Fallouh of the Queen Elizabeth Hospital in Birmingham, could be a solution.
In addition to the balloon, a second wire with a special sensor at the end – called a Doppler probe – is inserted into the same area.
This then bounces high-frequency sound waves off the red blood cells in the heart to get a picture of how much blood is flowing through the arteries.--
It also serves as an alert to paramedics by sending signals when blood flow has stopped – indicating there may be a problem.-
Both devices – the balloon and the probe – are easily withdrawn once the patient is clear, usually after 48 hours.
Patients who are monitored with this new device must stay in the hospital, and may have to stay longer than usual.
However, if this means that cardiac tamponade can be recognized early, and when it can be treated, it would be a huge step forward.
A sudden drop in blood pressure is currently one of the few warning signs of heart block.
If doctors find it quickly, they can treat it by draining the excess fluid.
However, the condition can easily be confused with other conditions such as congestive heart failure — where the heart doesn’t pump properly.
If not caught in time, cardiac tamponade often leads to emergency open-heart surgery to relieve pressure on the heart – a procedure with a fatality rate of up to 70%.
The tamponade device for cardiac output monitoring and tamponade diagnosis (PerDeCT) is currently a prototype.
However, its developers recently won a £500,000 grant from Innovate UK, a public body that funds the pioneering technologies, and it is due to undergo testing at Queen Elizabeth Hospital in the next year or so.