Occluder devices to combat congenital structural heart defects designed by the indigenous Aymara women suggest “excellent” clinical outcomes and have been approved by regulatory agencies in Canada, South America and the European Union.
For underserved children living in La Paz, Bolivia, who suffer from structural heart defects, open heart surgery is not an option. A team of weavers, biomedical engineers and physicians banded together to develop a biocompatible occlusive device to treat heart defects that can provide similar treatment as commercial-grade devices.
“Congenital structural heart defects are more frequent at higher altitudes possibly because of effects of low oxygen tension on pulmonary vascular resistance,” wrote physician Alexandra Heath, MD, PhD, of the Pulmonary Vascular Research Institute in Illinois, and colleagues in JAMA. “As pediatric cardiologists living in La Paz, Bolivia, we frequently encounter children with large functionally limiting defects—primarily patent ductus arteriosus with left atrial and ventricular dilation as large as the postductal aorta and atrial septal defects lacking appropriate borders for percutaneous occlusive therapy—that cannot easily be managed with commercially available devices.”
The weavers found a pattern similar to one used in commercial devices. The pattern, chakana, also known as the Andean cross, is a simple cross with a superimposed square, the physicians wrote.
“Symbolically the chakana is said to represent pure symmetry of a universe without beginning, end, center, or direction,” the physicians wrote. “Practically, it was an already-familiar pattern and technique that could be used to weave a device of variable size using a single strand of material without soldered or welded connections, so it could not corrode or break.”
The biomedical engineers and physicians determined nitinol, a nickel-titanium alloy would be the ideal material for the devices. Nitinol, the physicians noted, has elasticity and structural “memory,” that can easily be collapsed and inserted through a catheter to the heart. Upon insertion, the material can expand to its original shape.
“The devices are easy to deploy, which minimizes procedure time and child exposure to imaging radiation, and their elasticity makes them minimally traumatic to friable vessels and structures of young children,” the authors wrote.
The team trained 40 craftswomen in a laboratory to perfect their weaving skills and reproduce the double-disk net design. The chakana pattern is repeated 120 times per device. A circular mold is used with cylindrical structures arranged so that size and design are fixed.
“The true beauty of the devices lies in the simplicity of the design and deployment and in being a precise application and effective solution to a prevalent lethal health problem in the population of children we care for,” the authors wrote. “By producing handmade devices, the Aymara indigenous people also transfer their culture and skills to the production of medical devices and affirm the relevance of their cultural heritage—integrating the past with the present, culture with science, and the prospect of death with the hope of life. Together with the Aymara people, we are writing a new story inside the children who carry these woven microstructures in their hearts.”
As a senior news writer for TriMed, Subrata covers cardiology, clinical innovation and healthcare business. She has a master’s degree in communication management and 12 years of experience in journalism and public relations.