Vascular closure devices and methods providing hemostatic enhancement

Inventors

Yassinzadeh, Zia • Weitz, Jeffrey I. • Stafford, Alan

Assignees

Cardiva Medical Inc

Abstract

Vascular closure devices and methods for closing a blood vessel puncture site disposed at a distal end of a tissue tract are described. A combination of the body's own natural mechanism with chemical and/or biological agents is relied upon to accelerate the hemostatic process. Included are steps of introducing a closure device through the tissue tract and deploying an expansible member at a distal end of the device within the blood vessel to occlude the puncture site. A sealing member disposed proximal the expansible member is then displaced by retracting and tensioning a coil spring so as to expose a chemical and/or biological region or release region of the device. The retraction and tensioning of the coil spring is limited by a coupling member. Exposure of blood and tissue to the chemical and/or biological sealing member promotes the clotting processing to accelerate the occlusion process in the tract.

Core Innovation

The disclosure describes drug-eluting vascular closure devices for closing a blood vessel puncture site disposed at a distal end of a tissue tract. A tubular shaft is configured to advance through the tissue tract, carrying a hemostasis promoting agent deposited in a hemostasis promoting region disposed on the tubular shaft near its distal end. An expansible member is disposed on the tubular shaft distal to the hemostasis promoting region and is deployable within the blood vessel.

A tubular sealing member is slidably disposed over the tubular shaft and provides a barrier over the hemostasis promoting region in a distally advanced position and exposes the hemostasis promoting region in a proximally retracted position. A tensioning element is disposed coaxially over the tubular shaft, under the tubular sealing member and proximal the expansible member. Proximal retraction of the tubular sealing member relative to the tubular shaft exposes the hemostasis promoting region while applying tension to the tubular shaft in a proximal direction to seat the expansible member against the puncture site.

The disclosure addresses problems associated with prior approaches that rely on foreign-object hemostasis devices or hemostasis provided only inside the blood vessel. It contrasts drawbacks of injected thrombogenic mixtures and instead provides controlled exposure of chemical and/or biological hemostasis agents in the tissue tract proximal to the occlusion, so that the agent is revealed or released only after the occluder is seated in the vessel.

Agent examples explicitly discussed include thrombin, epinephrine, chitosan, kaolin, silica, and heparin inhibitors such as protamine sulfate, with soluble and insoluble forms described.

Claims Coverage

The document provides one independent claim (device) that includes four main inventive elements: a tubular shaft carrying a hemostasis promoting agent near its distal end, an expansible member deployable in the blood vessel, a proximally retractable tubular sealing member that covers and then exposes the hemostasis promoting region, and a coaxial tensioning element that coordinates exposure of the hemostasis promoting region with seating of the expansible member against the puncture site.

Across the independent claim, the core coverage is the coordinated system of an agent deposited near the distal end of a tubular shaft, a vessel-deployable expansible member, a tubular sealing member that blocks and then exposes the agent region, and a coaxial tensioning element that exposes the agent region while applying proximal tension to seat the expansible member against the puncture site.

Stated Advantages

Documented Applications