Anchoring an intravenous cannula

A method of using an intravenous cannula device, comprising:

• inserting a flexible catheter and a tissue anchor device of an intravenous cannula device through a skin penetration point while the intravenous cannula device is removably coupled to an inserter tool, the flexible catheter including a distal tip, the intravenous cannula device including a proximal connector hub external to the skin penetration point, the tissue anchor device positioned between the distal tip of the flexible catheter and the proximal connector hub, the tissue anchor device comprising at least one slotted circumferential ring comprising a plurality of circumferential ring components arranged about an outer surface of the flexible catheter, each of the plurality of circumferential ring components configured as an elongate arc segment extending along an outer wall of the flexible catheter in a direction about a circumference of the flexible catheter, each of the plurality of circumferential ring components spaced apart from an adjacent component and extending radially outward at an angle greater than 45°from the outer wall of the flexible catheter in a first direction toward the proximal connector hub and away from the distal tip of the flexible catheter when not subjected to an insertion force or a withdrawal force;
• removing the inserter tool from the intravenous cannula device such that a needle portion of the inserter tool is slidably withdrawn from a lumen of the flexible catheter while the tissue anchor device remains external to a targeted vessel and under a skin layer and while a distal opening of the flexible catheter remains in the targeted vessel;
• and
• removing the flexible catheter and the tissue anchor device of the intravenous cannula device from a subcutaneous region and through the skin penetration point, wherein each of the plurality of circumferential ring components are configured to shift from the first direction to a second direction away from the proximal connector hub and toward the distal tip of the flexible catheter when subjected to a withdrawal force during removal.

A method of using an intravenous cannula device, comprising:

• inserting a flexible catheter and a tissue anchor device of an intravenous cannula device through a skin penetration point while the intravenous cannula device is removably coupled to an inserter tool such that both a needle tip of the inserter tool extends distally of a distal opening of the flexible catheter of the intravenous cannula device and an inserter handle of the inserter tool extends proximally of a luer connector of a proximal connector hub of the intravenous cannula device;
• removing the inserter tool from the intravenous cannula device such that the needle tip of the inserter tool is slidably withdrawn from a lumen of the flexible catheter while the tissue anchor device remains external to a targeted vessel and under a skin layer and while a distal opening of the flexible catheter remains in the targeted vessel, the tissue anchor device comprising at least one slotted circumferential ring comprising a plurality of circumferential ring components arranged about an outer surface of the flexible catheter, each of the plurality of circumferential ring components spaced apart from an adjacent component at an attachment to the outer surface of the flexible catheter and extending radially outward from an outer wall of the flexible catheter, wherein the plurality of circumferential ring components have a first orientation in a rest state, wherein in the first orientation the plurality of circumferential ring components extend toward the proximal hub connector and radially outward at an angle greater than 45°from the outer wall of the flexible catheter;
• and
• in response to applying a withdrawal force to the proximal connector hub in a direction parallel to a longitudinal axis of the proximal connector hub, changing the plurality of ring components from the first orientation to a second orientation in which the plurality of ring components are prolapsed toward the distal end of the flexible catheter and away from the proximal connector hub, wherein the plurality of ring components return to the first orientation after being withdrawn from under the skin layer.