The invention is a closed complaint venous reservoir with at least one public wall having at least three innovative features: 1) the venous reservoir incorporates means that purge gas bubbles entering the venous reservoir without the user intervention, 2) the venous reservoir incorporates a cardiotomy reservoir, and 3) the pliable wall of the venous reservoir is sealed within a rigid housing allowing control of its atmospheric pressure, and therefore the pressure at which the wall collapses. The contribution of the three innovative features provides a collapsible complaint reservoir unitized with cardiotomy reservoir having air removal features and enabling vacuum augmented venous drainage (VAVD) that much of the open hardshell venous-cardiotomy reservoir unit, while retaining the advantages of the closed soft shell venous reservoir.
