Left atrial to femoral arterial bypass using the biomedicus pump for operations of the thoracic aorta. Left atrial to left femoral arterial bypass is an approach to operations of the thoracic aorta dating back to the late 1950s. Since that time, various modifications of the basic bypass circuit have evolved. In addition, temporary bypass shunts have also been described in a variety of positions. The goals of bypass of the thoracic aorta regardless of the technique include prevention of distal hypoperfusion, which can lead to paraplegia, limb loss, multiple organ failure, and sometimes death. Recently, there have been reports of the use of the biomedicus centrifugal pump in bypass circuits of the thoracic aorta. Our series, as well as the success of others, using this variation of a traditional bypass circuit of the thoracic aorta, establishes the biopump's capability of minimizing inherent complications in the bypass circuit. 