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Open Heart: Intracardiac Surgery at the University of Minnesota

The Bubbled Heart

Despite the effectiveness of controlled cross circulation, and the mixed success of using reservoirs of arterialized blood or a biological oxygenator, C. Walton Lillehei was certain that another - simpler - method was possible for open heart surgery.  In 1955, Lillehei asked Richard DeWall, a laboratory animal attendant who also ran the pump during cross circulation operations, to devise a simple oxygenating apparatus to take the place of a donor during open heart surgery.

Upon Lillehei’s suggestion, DeWall obtained inexpensive polyvinyl tubing regularly used in the food industry to use as a blood conductor. The inexpensive tubing could be discarded after each operation, thereby removing the necessity to clean and sterilize it for reuse.

DeWall constructed an apparatus through which deoxygenated blood was pumped through plastic tubing to a container where bubbles were introduced by needles inserted through a rubber stopper.  The tube provided a surface large enough for the blood to intake oxygen and allow for carbon dioxide to be eliminated.  Oxygenated blood rose to the top of the tube where it entered a de-bubbling chamber coated with Antifoam A, an anti-coagulant, where most of the bubbles were then removed from the blood.  The blood then flowed from the chamber down a long helical tube whereupon any residual bubbles rose up the column, and bubble-free blood descended to the bottom where it flowed through a reservoir and back into the body through a vein catheter.