Apparatus and methods for sealing a vascular puncture

Abstract

Apparatus for sealing a puncture communicating with a blood vessel includes a porous carrier formed from lyophilized hydrogel or other material. The plug may include at least first and second hydrogel precursors and a pH adjusting agent carried by the porous carrier in an unreactive state prior to exposure to an aqueous physiological environment. Once exposed to bodily fluids, the carrier expands as the lyophilized material hydrates to enhance and facilitate rapid hemostasis of the puncture. When the plug is placed into the puncture, the natural wetting of the plug by bodily fluids (e.g., blood) causes the first and second precursors to react and cross-link into an adhesive or “sticky” hydrogel that aids in retaining the plug in place within the puncture.

What is claimed is: 
     
         1 . An apparatus for sealing a puncture extending through tissue, comprising:
 a cartridge comprising a proximal end, a distal end sized for insertion into a puncture through tissue, and a lumen extending between the proximal and distal ends;   a plug disposed within the cartridge lumen, the plug comprising a lumen extending between proximal and distal ends thereof;   a pusher member disposed within the cartridge lumen for deploying the plug from the cartridge when the cartridge is retracted relative to the pusher member;   a positioning member comprising an elongate member and an expandable positioning element carried on a distal end of the elongate member, the elongate member received through the lumens of the plug and the cartridge such that the cartridge, plug, and pusher member are advanceable from a proximal position on the positioning member to a distal position wherein the plug is disposed adjacent the positioning element; and   cooperating elements on the pusher member and the positioning member that limit subsequent movement of the pusher member relative to the positioning member when the pusher member is advanced to the distal position.