Researchers have developed a new heart valve replacement device that does not require advanced cardiac surgical facilities or sophisticated cardiovascular imaging and offers hope for the thousands of patients suffering from rheumatic heart disease.Rheumatic heart disease is caused by rheumatic fever, which results from a streptococcal infection. Patients develop fibrosis of the heart valves, leading to valvular heart disease, heart failure and death. "Over the past decade heart valve surgery has been revolutionised by transcatheter aortic valve implantation (TAVI), where heart valves are replaced or repaired via a catheter, obviating the need for open heart surgery or a heart-lung machine," said lead author Jacques Scherman, Cardiac Surgeon at the University of Cape Town, South Africa.The team developed a novel TAVI device which is "non-occlusive", meaning that there is no need to stop blood circulating to the body with rapid ventricular pacing -- quick heart beats. The device is also "self-locating" and does not require sophisticated cardiac imaging for positioning.Testing the device in a sheep model, the team found that the device was easy to use and positioned the valve correctly, and the procedure could be performed without rapid ventricular pacing.
"We showed that this new non-occlusive, self-locating TAVI delivery system made it easy to perform transcatheter aortic valve replacement," Scherman said. "Using tactile feedback the device is stabilised in the correct position within the aortic root during the implantation. It also has a temporary backflow valve to prevent blood leaking backwards into the ventricle during the implantation of the new valve," Scherman explained.All these factors together allowed for a slow, controlled implantation compared to the currently available balloon expandable devices. Further, this simplified approach to transcatheter aortic valve replacement could be done in hospitals without cardiac surgery at a fraction of the cost of conventional TAVI. It has the potential to save the lives of the large numbers of rheumatic heart disease patients in need of valve replacement, the researchers said.The findings were presented at the SA Heart Congress 2016, in Cape Town recently.