Apparatus and methods are known for accessing a patient's vasculature percutaneously to perform a procedure within the vasculature, and for sealing the puncture that results after completing the procedure. For example, a hollow needle may be inserted through a patient's skin and overlying tissue into a blood vessel. A guide wire may be passed through the needle lumen into the blood vessel, whereupon the needle may be removed. An introducer sheath may then be advanced over the guide wire into the vessel, e.g., in conjunction with or subsequent to one or more dilators. A catheter or other device may be advanced through the introducer sheath and over the guide wire into a position for performing a medical procedure. In this manner, the introducer sheath may facilitate introducing various instruments into the vessel, while minimizing trauma to the vessel wall and/or minimizing blood loss. Upon completing the procedure, the instrument(s) and introducer sheath may be removed, leaving a puncture extending between the skin and the vessel.
To seal the puncture, external pressure may be applied to the overlying tissue, e.g., manually and/or using sandbags, until hemostasis occurs. This procedure, however, may be time consuming and expensive, requiring as much as an hour of a medical professional's time. It is also uncomfortable for the patient, and may require the patient to remain immobilized in an operating room, catheter lab, or holding area. In addition, a risk of hematoma exists from bleeding before hemostasis occurs.
Various apparatus and methods have been suggested for sealing a percutaneous puncture instead of using external pressure. For example, U.S. Pat. No. 5,108,421 to Fowler discloses a collagen plug that may be delivered into a puncture through tissue. In one embodiment, a catheter is inserted through the puncture into the blood vessel. A balloon on the catheter is expanded and retracted until the balloon is disposed adjacent the puncture at the wall of the vessel. The plug may be advanced into the puncture until the plug contacts the balloon, thereby preventing the plug from entering the vessel. Once the plug is positioned within the puncture, the balloon may be deflated and withdrawn, leaving the plug therein to expand and seal the puncture and/or to promote hemostasis.
By way of another example, U.S. Pat. Nos. 5,192,302 and 5,222,974 issued to Kensey et al. describe a biodegradable collagen plug that may be delivered through an introducer sheath into a puncture site. The disclosed plug, however, may be difficult to position properly with respect to the vessel, which may be significant since it is generally undesirable to expose the collagen material within the bloodstream where it may float downstream and cause an embolism.