Securing a catheter device
Some embodiments of a medical system include a catheter device, such as an intravenous cannula device, having an external anchor device and a subcutaneous anchor device to secure a distally extending cannula of the device in a selected position relative to a skin penetration point.
1 . A medical system for anchoring an intravenous cannula device with respect to a skin surface, the system comprising:
a proximal hub comprising:
a hub body having a proximal end, a distal end, and a longitudinal axis extending from the proximal end to the distal end; and
an intravenous cannula comprising:
a flexible catheter having an exterior circumferential surface configured to extend through a skin penetration point into a target body vessel, the flexible catheter extending distally of the proximal hub to a distal opening at a distal end of the flexible catheter; and
a tissue anchor device positioned on an exterior surface of the flexible catheter between the distal opening and the distal end of the hub; and
an external anchor device movably coupled along the longitudinal axis to the hub body, the external anchor device configured to at least partially surround the flexible catheter, wherein the external anchor device defines a stopper element with a lateral dimension greater than the exterior circumferential surface of the flexible catheter; and
wherein the tissue anchor device is configured to anchor under a skin layer of a patient and the external anchor device is configured to be positioned distal to the hub body and proximal of the tissue anchor device such that the external anchor device is adjacent to the skin surface.
2 . The system of claim 1 , wherein the external anchor device is formed as an integral part of the hub body, extending distal of the hub body about the flexible catheter.
3 . The system of claim 2 , wherein the external anchor device is formed as a protrusion from the hub body, and the protrusion has a flat surface configured to mate with the skin surface.
4 . A medical system for anchoring an intravenous cannula device with respect to a skin surface, the system comprising:
a proximal hub comprising:
a hub body having a proximal end, a distal end, and a longitudinal axis extending from the proximal end to the distal end; and
an external anchor device movably coupled along the longitudinal axis to the hub body and configured to at least partially surround a flexible catheter, the external anchor device having an advancement mechanism and a contact portion, the contact portion having a lateral dimension greater than a diameter of a skin opening dimension defined by the flexible catheter, and the external anchor device configured to be advanced in a direction of the longitudinal axis of the hub body along the flexible catheter; and
an intravenous cannula comprising:
the flexible catheter configured to extend through a skin penetration point and define the skin opening dimension, the flexible catheter extending distally of the proximal hub to a distal opening at a distal end of the flexible catheter; and
a tissue anchor device positioned on an exterior surface of the flexible catheter between the distal opening and the distal end of the hub; and
wherein the tissue anchor device is configured to anchor under a skin layer of a patient and the external anchor device is configured to be positioned distal of the hub body and proximal of the tissue anchor device such that the external anchor device is adjacent to the skin surface.
5 . The system of claim 4 , wherein upon application of a force to the advancement mechanism in a direction parallel to the longitudinal axis, the contact portion is advanced distal of the distal end of the hub body along the flexible catheter.
6 . The system of claim 5 , wherein the contact portion is coupled to the advancement mechanism by a rigid extension.
7 . The system of claim 6 , wherein the contact portion is formed as a ring that surrounds the flexible catheter.
8 . The system of claim 6 , wherein the contact portion has a flat surface which is flexible.
9 . The system of claim 8 , wherein the contact portion is formed as a tubular cage that surrounds the flexible catheter.
10 . The system of claim 4 , wherein the distal end of the hub body includes an o-ring to reduce ingress of blood into the hub body.
11 . A method for securing an intravenous cannula in a selected position, the method comprising:
inserting a distal portion of an intravenous cannula into a skin penetration point of a skin surface;
advancing the intravenous cannula until a distal end enters a target body lumen and at least one subcutaneous anchor is positioned in a subcutaneous region under the skin surface;
engaging an external anchor by applying a first force to a tab of the external anchor in a first direction parallel to a longitudinal axis of the intravenous cannula and toward the skin surface, to secure the intravenous cannula in a position above and adjacent to the skin surface;
performing a medical procedure using the intravenous cannula;
after the medical procedure is performed, disengaging the external anchor by applying a second force to the tab of the external anchor in a second direction parallel to a longitudinal axis of the intravenous cannula and away from the skin surface; and
removing the intravenous cannula through the skin penetration point.
12 . The method of claim 11 , further comprising:
inserting a needle portion of an inserter tool through the skin penetration point and into a targeted vessel, wherein the intravenous cannula is removably coupled to the inserter tool such that a flexible catheter of the intravenous cannula is advanced through the skin penetration point and into the targeted vessel while the at least one subcutaneous anchor integrally formed as a unitary structure with an outer wall of the flexible catheter is positioned under a skin layer;
engaging the external anchor with a surface of the skin layer, wherein the external anchor is movably positioned along the flexible catheter of the intravenous cannula to a position adjacent the surface of the skin layer, and wherein the external anchor has a contact surface which is configured to be positioned in contact with the surface of the skin layer;
removing the inserter tool from the intravenous cannula such that the needle portion of the inserter tool is slidably withdrawn from a lumen of the flexible catheter while a distal opening of the flexible catheter remains in the targeted vessel to provide fluid communication with the targeted vessel, the external anchor remains in contact with the surface of the skin layer, and the at least one subcutaneous anchor remains under the skin layer;
threadably engaging an external fluid line to a proximal connector hub of the intravenous cannula while the flexible catheter remains in the targeted vessel, the external anchor remains in contact with the surface of the skin layer, and the at least one subcutaneous anchor remains under the skin layer, wherein the external anchor is positioned between a distal tip of the flexible catheter and the proximal connector hub, and wherein the at least one subcutaneous anchor is positioned distal of the external anchor toward the distal tip of the flexible catheter; and
infusing a fluid from the proximal connector hub through the lumen of the flexible catheter and into the targeted vessel.