title: Current use of substitute heart valves.
abstract: Although repair of diseased heart valves became possible in the 1940s, replacement of such valves had to await the development and refinement of the heart lung machine, as well as the advent of serviceable valve substitutes. Early investigators were hindered by the idea that alternative valves should closely resemble anatomic ones. Not until the early 1960s, with the introduction of caged- ball prostheses by Harken and Starr, did effective valve replacement become possible. Since that time, substitute heart valves have continued to evolve, and many improvements have been made in their design and fabrication. As of 1988, approximately 51,000 valves were being implanted annually in the United States.
authors.affiliation: University of Texas Medical School, Houston, Texas.
authors.forename: D A
authors.initials: DA
authors.lastname: Cooley