Engineers and clinicians at UCLA’s Henry Samueli School of Engineering and Applied Science and Mattel Children’s Hospital have developed a novel nitinol-based cardiac valve. It turns out that nitinol memory-retaining alloy has allowed this team to develop a cardiac valve for pedi patients that has a “butterfly design that opens or hinges from the middle of the valve rather than the edges” and hence could be deliverable via femoral artery catheterization:
Using a super-elastic, shape-memory metal alloy called “thin film nitinol,” UCLA engineers are developing a collapsible heart valve for children that can be loaded into a catheter, inserted into a vein in the groin area, guided into place and then deployed in a precise location within the heart. As the valve is released from the catheter, it springs back to its original shape and begins to function…
While catheter-based valve replacement procedures already are revolutionizing valve replacement for larger patients, smaller children have not yet benefited from this technology. Although many companies are competing to develop the ideal transcatheter heart valve, most of these valves are bulky and can be used only in adults. Thin film nitinol could allow doctors at UCLA to make a transcatheter heart valve suitable for use even in small children.
“By collaborating with UCLA Engineering, we are creating a pediatric heart valve that has great strength and biocompatibility. It could mean a shortened procedure, a lower level of risk, and much less stress on the patient and their family. It also will mean a lower cost to the health care system,” Levi said. “Our valve is presently being designed for replacement of the pulmonary valve, but eventually may also be able to be used for the aortic valve.”
The UCLA team also has used thin film nitinol successfully in other biomedical applications such as stents – short narrow metal mesh tubes inserted into an artery or bile duct to keep blocked passageways open – as well as in other applications.
“Although the medical community has used bulk nitinol for the past decade in stents and other implantable biomedical devices, thin film nitinol has yet to be incorporated into a commercially available biomedical device,” Carman said.
“Recent studies we’ve conducted have shown that thin film nitinol can be used to cover stents and to provide a barrier in preventing regrowth of tissue into stented arteries and veins. Beyond its use in either percutaneously or surgically placed valves, I anticipate that thin film nitinol will have a wide variety of applications in the development of future implantable biomedical devices for both adults and children,” Levi added.