5th October 2015 — National University of Singapore (NUS)
Mitral Regurgitation (MR) affects 250 to 350 Singaporeans per year, and the failure of MR clinical treatment can lead to heart failure and death. A team of researchers from NUS has developed a novel prosthetic heart valve for the treatment of MR, VeloX which can be implanted through a small incision ~ 5cm at the left ribs.
The conventional approaches of MR are: i) heart replacement; ii) repairing the heart valves, either of the treatment options will require an open heart surgery. Though the clinical outcomes of open heart surgeries have shown to be robust, it is often considered a risky surgical procedure and patients who are very frail may not be recommended for MR surgical treatments. VeloX is hence particularly beneficial to patients who are of high surgical risk.
According to Associate Professor Leo Hwa Liang from the Department of Biomedical Engineering at NUS' Faculty of Engineering, 'The newly designed prosthetic heart valve is considered a Chimera. The materials consist of an alloy, Nitinol; nickel and titanium, and it is covered by Bovine tissue.'
'Good research collaborations bring good outcomes, designs and products,' said Dr Jimmy Hon from the Department of Surgery at the NUS Yong Loo Lin School of Medicine. 'VeloX will restore the unidirectional flow of the blood in the left heart and help alleviate the symptoms associated with mitral regurgitation. This transcatheter valve offers palliative treatment for the patients who were denied surgery, especially those with multiple co-morbidities.'
Pioneered by Assoc Prof Leo and Dr Jimmy Hon, the novel device has just entered its preclinical phase and it addresses a clinical gap in the current treatment of MR.
'The mitral annulus has a very complex structure, so it is particularly challenging to deploy and anchor a prosthetic valve into the constricted region. Optimal positioning is crucial as any mal-positioning can be detrimental for patients. One of the unique features of VeloX is its ability to be self-centering, hence enabling it to achieve an optimal position after being implanted,' explained by Assoc Prof Leo.
The research project is supported by the Medical Engineering Research & Commercialization Initiative (MERCI) under the Department of Surgery of the NUS Yong Loo Lin School of Medicine.
Other members of the team include: Mr Kenneth Chan Zhi Wei, a current Biomedical Engineering Masters student who is working on the design of the device under the supervision of Assoc Prof Leo, and Dr Elynn Phang Hui Qun of MERCI, who is managing the commercialization of the invention.
Interesting facts about VeloX
The tiny device comprises a prosthetic heart valve made of pericardial tissue 'stitched' within a self-expanding, polymer coated nitinol alloy stent frame specially designed to prevent leakage. To implant the device, the prosthetic valve is compressed to the thickness of a pencil and loaded into a catheter. Together with the guidance of ultrasound and other imaging techniques, the catheter is inserted into the patient through a small incision either at the leg or the left ribs to deliver the VeloX straight to the left heart, and to be positioned to the patient's diseased mitral valve. To facilitate accurate placement, the device is designed to be retrievable and repositionable.
Mitral Regurgitation (MR) is a cardiac malfunction which causes a backward flow of the blood from the top to the lower heart chamber; left atrium to left ventricle. MR disease reduces the amount of oxygenated blood to the rest of the body, therefore the heart has to work harder to meet the demands for oxygenated blood to reach the muscles and organs. If it is untreated, the condition will lead to congestive heart failure.