The Hemex Inc. Venture

Abstract

Originally, Jerome Klawitter, professor of ceramic engineering, was contracted by CarboMedics to determine if Pyrolite Carbon might be used in orthopedic prosthetic devices. Thinking outside of the box, having seen the St. Jude Medical valve design, Klawitter thought he could make a better design. He filed a patent and set up an R&D partnership to develop his valve concept. CarboMedics was not able to produce the concept but was able to modify its process by using a “mandrel process” patented by CarboMedics to make the design. Klawitter’s partnership formed Hemex, Inc. and called its valve the Duromedics bileaflet valve. Hemex carried out all of the in vitro and animal testing required by the US FDA and was granted a pre-market approval (PMA) by the FDA in 1986. After 7000 valves were implanted, Baxter (Edwards CVS Division) purchased Hemex, Inc. in spite of low incidents of cavitation damage. After the purchase, increasing incidences of cavitation damage caused industry-wide concern. In 1988, after 12 valve failures out of 20,000 implanted, the Duromedics valve was taken off the market. Professor Ernst Wolner at the University of Vienna reported a 10-year follow-up of the Duromedics valve.