Abstract: A device for promoting hemostasis in a blood vessel puncture is employed with an introducer that accesses the puncture through an incision. The introducer has an open distal end positionable at the puncture, an external portion with an open proximal end, and an axial channel therebetween. The device includes a hollow catheter, dimensioned to pass through the introducer channel, having a distal end to which is attached an expansible compression element, which may be an inflatable balloon, a collapsible prong assembly, or a resilient foam pad. The compression element is collapsed when the distal end of the catheter is enclosed within the introducer. When the catheter and the introducer are located the desired distance from the puncture, the introducer is displaced axially relative to the catheter to expose the compression element to the subcutaneous tissue, whereupon the compression element is expanded.