American surgeon Clarence Dennis (1909-2005) invented one of the first heart-lung bypass machines, and in 1951 was the first to use it to perform open-heart surgery. Heart-lung bypass technology--perfected by Dennis, John Gibbon, and others--eliminated the major barriers to surgical treatment of cardiovascular conditions. During his 60-year career, Dennis's surgical research produced a wide range of surgical techniques and tools, and important contributions to vascular physiology. He was also an outstanding medical educator, first at the University of Minnesota, then at SUNY Downstate Medical Center (where he chaired the department of surgery for 20 years), and finally at SUNY Stony Brook. The National Library of Medicine is the repository for the Clarence Dennis Papers, which range from 1927 to 2003. The collection contains laboratory notes, correspondence, publications, and professional papers.

As part of its Profiles in Science project, the National Library of Medicine has made available online a digitized selection of the Clarence Dennis Papers. This website provides access to the portions of the Clarence Dennis Papers that are now publicly available. Individuals interested in conducting research using the full collection of Clarence Dennis Papers should contact the National Library of Medicine.

This Profile is designed to introduce you to the various phases of Dennis's medical career and professional life. Narrative sections available from the navigation bar under "The Story" focus on Dennis's life and major contributions to surgical research and education.

Researchers can search the digitized items using the Search box or browse all Documents and Visuals in the collection by selecting "Collection Items" from the navigation bar.