Apparatus and methods for sealing a vascular puncture

An apparatus for sealing a puncture through a vessel wall, the apparatus comprising:

• a positioning assembly including an expandable member disposed at a distal portion of the positioning assembly, the expandable member configured to move between an unexpanded state and an expanded state;
• a support member, the positioning assembly configured to move axially within the support member;
• a tubular member through which the support member is axially advanceable;
• and
• a handle comprising an outer housing portion and a depressible button, wherein the button is provided in a first position in which the button is operatively coupled to the tubular member and operatively uncoupled from the support member, the button being moveable relative to the outer housing portion from the first position to a second position to retract the tubular member and advance the support member;
• wherein the button has a partially depressed position in which the button is operatively coupled to the support member, the tubular member is positioned proximally compared to its position when the button is in the first position, a sealant disposed at the distal portion of the positioning assembly is at least partially exposed, and the support member is in substantially the same position as it is when the button is in the first position.