US20220257902A1

US20220257902A1 - Vascular access catheter with lateral leading edges

Info

Publication number: US20220257902A1
Application number: US17/739,448
Authority: US
Inventors: Michael Gabriel Tal
Original assignee: Individual
Current assignee: Embrace Medical Ltd
Priority date: 2020-05-27
Filing date: 2022-05-09
Publication date: 2022-08-18
Also published as: JP2023536209A; CA3182025A1; AU2021281484A1; WO2021242734A3; US20230191085A1; WO2021242734A2; CN115605255A; EP4157427A2

Abstract

A vascular access catheter and a method for inserting the catheter into a blood vessel. The catheter comprising a catheter body enclosing a lumen, and a catheter tip comprising a distal edge surrounding an opening opened to the lumen. The distal edge includes a pair of lateral leading edges, each of the lateral leading edges is curved downwardly and proximally from a respective front portion of the distal edge. The vascular access catheter can be provided in a vascular access kit further comprising access needle with hollow needle body and beveled tip ending with sharp needle edge.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation-in-Part of PCT application No. US2021/34016 filed on May 25, 2021, which claims the benefit of U.S. Provisional Patent Application No. 63/030,410, filed on May 27, 2020, the entire contents of which are hereby incorporated by reference herein.

FIELD OF THE INVENTION

The present disclosure relates to devices and methods for accessing a blood vessel, and more particularly, but not exclusively, to devices and methods for inserting a catheter into a blood vessel over an access needle.

BACKGROUND OF THE INVENTION

Peripheral intravenous (PIV) catheter insertion is an invasive hospital procedure for administrating medication or other fluids, commonly involves needle insertion into a peripheral vein followed by introduction of the catheter over the needle. For fluid administration the needle is withdrawn, leaving at least the catheter tip and opening patent for fluid delivery. PIV catheterization traditionally involves substantial failure rates indicated by removal of the catheter from the vein before the end of its intended dwell time. Common reasons for failure include “infiltration”, in which the catheter and/or needle penetrates vein wall portion opposing the entry point to the vein, and “occlusion” which is loss of ability to infuse due to thrombosis in the catheter or vein itself, optionally due to infiltration and vein inflammation (phlebitis).
Another drawback commonly associated with PIV catheter insertion into peripheral veins relates to the pain caused by catheter progression through the skin following the initial puncturing with the access needle beveled tip.

SUMMARY OF THE INVENTION

The present disclosure relates to devices and methods for accessing a blood vessel, and more particularly, but not exclusively, to devices and methods for inserting a catheter into a blood vessel over an access needle.
In certain embodiments, there is provided a vascular access catheter that includes an elongated tubular catheter body enclosing a lumen, the catheter body has a plane of symmetry coinciding with a median plane and includes a catheter tip ending with a catheter distal end and comprising a distal edge at the catheter distal end surrounding an opening opened to the lumen, the distal edge includes: (a) a pair of lateral leading edges located at opposing sides of the median plane, each of the lateral leading edges is curved downwardly and proximally from a respective front portion of the distal edge, (b) a bottom edge portion extending between and below the lateral leading edges and spanning a bottom portion of the opening, and (c) a top edge portion extending between and above the lateral leading edges and spanning a top portion of the opening.
In some embodiments, the lateral leading edges are configured to penetrate through an aperture in a bodily tissue and to gradually expand the aperture downwardly in parallel to the median plane, when the catheter tip is pushed distally through the aperture, before the bottom edge portion penetrates through the aperture.
In some embodiments, the bodily tissue is a skin tissue, and the catheter tip is configured to pass through the aperture into a blood vessel over an access needle after the aperture is formed by the access needle.
In some embodiments, the vascular access catheter is configured for gradually stretching the skin tissue while expanding the aperture for reducing pain associated with catheter penetration through skin into a blood vessel over a needle.
In some embodiments, the bottom edge portion and/or the top edge portion is curved generally proximally.
In some embodiments, the vascular access catheter is configured such that the lateral leading edges penetrate through the aperture before the bottom edge portion and the top edge portion, when pushed through the aperture at an acute angle relative to an outer surface of the bodily tissue.
In some embodiments, each of the lateral leading edges is curved upwardly and proximally from the respective front portion of the distal edge.
In some embodiments, the lumen is cylindrical along a portion of the catheter body proximally to the catheter tip and tapers along a portion of the catheter tip.
In some embodiments, radius of curvature of each of the lateral leading edges is smallest adjacent to the respective front portion and/or greatest adjacent to the bottom edge portion.
In some embodiments, radius of curvature of each of the lateral leading edges gradually increases between the respective front portion and the bottom edge portion.
In some embodiments, the bottom edge portion includes or merges with a sliding surface, the sliding surface is at least partially parallel, or inclined at a shallow angle, to the bottom edge portion.
In some embodiments, the sliding surface forms a shaped area bounded by and between a distal parabola and a proximal parabola, the distal parabola has a smaller focal length than the proximal parabola.
In some embodiments, the sliding surface is at least partially curved.
In certain embodiments, there is provided a vascular access kit that includes the vascular access catheter and an access needle comprising a beveled tip ending with a distal sharp needle edge.
In some embodiments, the kit comprising coupling means configured to fixedly connect the catheter body to the access needle, wherein the beveled tip protrudes distally from the lumen through the opening, such that a plane of symmetry of the access needle coincides with the median plane and the beveled tip is inclined distally and downwardly towards the distal sharp needle edge from a top needle end extending through the opening top portion to a bottom needle end extending through the opening bottom portion.
In some embodiments, the catheter is configured to accommodate the access needle through the lumen and the opening in at least two configurations comprising a tissue-penetration configuration wherein the beveled tip fully extends from the lumen distally to the catheter distal end, and a safety configuration wherein the beveled tip fully resides within the lumen proximally to the catheter distal end.
In certain embodiments, there is provided a method for inserting a catheter into a blood vessel using the kit. The method may include providing the vascular access catheter connected to the access needle, wherein the beveled tip protrudes distally from the lumen through the opening, such that a plane of symmetry of the access needle coincides with the median plane and the beveled tip is inclined distally and downwardly towards the distal sharp needle edge from a top needle end extending through the opening top portion to a bottom needle end extending through the opening bottom portion. The method may include forming an aperture in a skin tissue covering the blood vessel with the beveled tip. The method may include pushing the catheter body through the aperture at an acute angle relative to an outer surface of the skin tissue, thereby expanding the aperture sideways perpendicularly to the median plane with the pair of lateral leading edges followed by gradually expanding the aperture downwardly in parallel to the median plane until the bottom edge portion penetrates through the aperture.
In some embodiments, the top edge portion penetrates through the aperture following full or partial penetration of the bottom edge portion.
In some embodiments, the method includes inserting the beveled tip and/or the catheter tip into the blood vessel until visualizing blood drawn from the blood vessel into the access needle and/or the catheter body
In some embodiments, the inserting is followed by pushing the catheter body distally relative to access needle and removing the access needle from the blood vessel.
In some embodiments, the inserting is followed by penetrating across a wall of the blood vessel such that the beveled tip protrudes distally from the blood vessel, then drawing the beveled tip back into the blood vessel until visualizing blood drawn from the blood vessel into the access needle and/or the catheter body, and then pushing the catheter body distally relative to access needle and removing the access needle from the blood vessel.
All technical or/and scientific words, terms, or/and phrases, used herein have the same or similar meaning as commonly understood by one of ordinary skill in the art to which the invention pertains, unless otherwise specifically defined or stated herein. Illustrative embodiments of methods (steps, procedures), apparatuses (devices, systems, components thereof), equipment, and materials, illustratively described herein are exemplary and illustrative only and are not intended to be necessarily limiting. Although methods, apparatuses, equipment, and materials, equivalent or similar to those described herein can be used in practicing or/and testing embodiments of the invention, exemplary methods, apparatuses, equipment, and materials, are illustratively described below. In case of conflict, the patent specification, including definitions, will control.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative description of some embodiments. In this regard, the description taken together with the accompanying drawings make apparent to those skilled in the art how some embodiments may be practiced.

In the drawings:

FIG. 1A-1B illustrate an exemplary over-the-needle catheter, according to some embodiments:

FIGS. 2A-2C illustrate views of an exemplary vascular access kit, according to some embodiments;

FIGS. 3A-3C illustrate views of an exemplary vascular access catheter of the kit shown in FIG. 2A, according to some embodiments;

FIGS. 4A-4E schematically illustrate a first set of exemplary scenarios representing steps in a method for accessing a blood vessel using the kit shown in FIG. 2A, according to some embodiments;

FIGS. 5A-5F schematically illustrate a second set of exemplary scenarios representing steps in a method for accessing a blood vessel using the kit shown in FIG. 2A, according to some embodiments;

FIG. 6A-6B illustrate, respectively, a side cross-sectional view and an isometric view of a frontal tip of a first exemplary vascular access catheter comprising opposing lateral leading edges, configured for penetrating into a blood vessel over a needle, according to some embodiments;

FIGS. 7A-7B illustrate, respectively, a side cross-sectional view and an isometric view of a frontal tip of a second exemplary vascular access catheter comprising opposing lateral leading edges, configured for penetrating into a blood vessel over a needle, according to some embodiments; and

FIGS. 8A-8C schematically illustrate a set of exemplary scenarios representing steps in a method for penetrating a blood vessel using the catheter shown in FIG. 6A over a needle, according to some embodiments.

DETAILED DESCRIPTION

Certain embodiments relate to devices and methods for accessing a blood vessel, and more particularly, but not exclusively, to devices and methods for inserting a catheter into a blood vessel over an access needle.
In some embodiments, the catheter has a catheter tip ending with a distal edge that has different structural and/or functional features over a top portion of the catheter tip versus over a bottom portion of the catheter tip, such that the catheter tip is configured to interact differently with an internal wall surface of the blood vessel when engaging the blood vessel wall with the bottom portion than with the top portion of the catheter tip, under same forces and conditions, when the catheter tip is not internally supported by the needle. In some embodiments, the catheter tip bottom portion is constructed and/or shaped differently than the catheter tip top portion close to the distal edge. In some such or other embodiments, the distal edge is shaped differently closer to the bottom portion than to the top portion of the catheter tip.
FIGS. 1A-1B illustrate an exemplary over-the-needle catheter 100 configured for example as a peripheral intravenous catheter. Catheter 100 includes a catheter elongated body 101 ending with a catheter tip 102 and connected with proximal end thereof to a catheter handheld portion 103. Handheld portion 103 includes wings 104 configured for manual handling and/or for catheter securing to patient's body such as by using adhesives. Handheld portion also 103 optionally includes a syringe connector 105 configured for connecting to a syringe for facilitating injection of fluids (e.g., medication).
Catheter 100 may be provided in a kit for peripheral intravenous access, also comprising an access needle 107. As shown, needle 107 is configured to extend through lumen of catheter body 101, and needle tip 108 thereof is configured to fully protrude distally from catheter tip 102 when access needle 107 fully extends through and properly secured to handheld portion 103 and oriented (rotationally) relative thereto using needle securing and/or orienting member 109. Connected to a proximal end of access needle 107 is a line connector 106 which is configured for connecting to a syringe and/or optionally to an intravenous infusion line. Needle 107 can be partially or fully withdrawn (in a proximal direction) relative to catheter tip 102 after detaching from handheld portion 103 and pulling access needle 107 with needle wing 110.
As shown in FIG. 1B, catheter tip 102 has a distal edge 111 between a top portion 112 and a bottom portion 13 of catheter tip 102, wherein distal edge 111 is shaped and/or configured differently adjacent to bottom portion 113 than adjacent to top portion 112.
In some embodiments, the catheter can be inserted into a blood vessel using one or more of the following steps (not necessarily in same order):
> verifying that the catheter is positioned properly such that its outer surface along the bottom portion of the catheter tip is directed towards the blood vessel, and/or that its outer surface along the top portion of the catheter tip is directed away from the blood vessel;
> inserting an access needle into the blood vessel until blood enters the access needle and can be seen in an optional flashback chamber which can be provided with the kit or integrated in the catheter or parts thereof:
> pushing the access needle with the catheter, or pushing the catheter over the access needle, towards an inner (e.g., deeper) surface of a wall of the blood vessel while the catheter tip is internally supported by the access needle;
> moving the catheter body relative to the access needle, such that a tip of the catheter is unsupported internally by the access needle (commonly resulting in that blood becomes visible inside the catheter between the catheter tube and the needle);
> engaging the inner surface with the bottom portion of the catheter tip and/or with a portion of the distal edge close to the bottom portion; and
> sliding on the inner surface by advancing the catheter distally into the blood vessel.
FIGS. 2A-2C illustrate views of an exemplary vascular access kit 200 comprising at least a vascular access catheter 201 and an access needle 202. FIG. 2A shows catheter 201 and access needle 202 separated, and FIG. 2B shows access needle 202 extending through catheter 201 and fixedly connected thereto in a predetermined relative lengthwise position. FIG. 2C shows an enlarged (zoom-in) view of a distal portion of kit 200 in FIG. 2B, showing beveled tip 203 of access needle 202 and catheter tip 204 of catheter 201. FIGS. 3A-3C illustrate views of catheter 201 including a partial isometric view of a distal length of catheter 201 showing part of catheter body with catheter tip 204 (FIG. 3A), an enlarged view showing front portion of catheter tip 204 (FIG. 3B), and a side cross sectional view of a distal length of catheter 201 including catheter tip 204 (FIG. 3C).
Catheter 201 includes an elongated tubular catheter body 205 enclosing a lumen 206. Lumen 206 is cylindrical along a portion (e.g., most) of catheter body 205 proximally to catheter tip 204 and tapers along a portion of catheter tip 204. Catheter tip 204, which is the front (distal) portion of catheter body 205, ends with a catheter distal end 207 and comprising a distal edge 208 at the catheter distal end 207 surrounding an opening 209 opened to lumen 206. Access needle 202 includes a hollow needle body 210 and a needle beveled tip 203 that ends with a distal sharp needle edge 211. Catheter 201 is configured to accommodate access needle 202 through lumen 206 and opening 209 in at least two configurations comprising a ‘tissue-penetration configuration’ (shown in FIGS. 2B, 4A and 5A, for example) wherein beveled tip 203 fully extends from lumen 206 distally to catheter distal end 207, and a ‘safety configuration’ (shown in FIGS. 4B and 5B, for example) wherein beveled tip 203 fully resides within lumen 206 proximally to catheter distal end 207. Lumen 206 decreases in diameter along catheter tip 204 to a sealing diameter smaller than a diameter of access needle proximally to beveled tip 203, so as to form a seal around access needle 202 for preventing blood from accessing into lumen 206 via opening 209 when in the tissue-penetration configuration, and to facilitate access of blood into lumen 206 via opening 209 when in the safety configuration. Catheter 201 and access needle 202 includes mating portions of coupling means 212, optionally in a form of luer fitting as shown, configured to fixate access needle 202 in catheter 201 in the tissue-penetration configuration.
Distal edge 208 includes a front edge portion 213 spanning a top portion of opening 209, and an inclined edge portion 214 spanning a bottom portion of opening 209 and inclining (towards bottom end of catheter tip 204) proximally away from front edge portion 213, relative to a longitudinal axis X of catheter body 201. The top portion of opening 209 relates to the cross-sectional area of opening 209 above longitudinal axis X. and the bottom portion of opening 209 relates to the cross-sectional area of opening 209 below longitudinal axis X (as shown in FIG. 3C). Front edge portion 213 substantially coincides with a transverse plane TP of catheter body 205 crossing perpendicularly to longitudinal axis X. Optionally, front edge portion 213 spans at least half of a cross section of catheter body 205 at distal end 207. Optionally, front edge portion 213 is substantially parallel to transverse plane TP, at least in most part thereof. Inclined edge portion 214 is inclined to longitudinal axis X at an average angle greater than 20°, optionally particularly greater than 40°, optionally particularly greater than 60°, and/or is inclined to front edge portion 213 or to transverse plane TP at an average angle smaller than 45°, optionally particularly smaller than 30°, optionally particularly smaller than 20°.
In some embodiments, front edge portion 213 is at least partially flat, and inclined edge portion 214 is at least partially curved. Optionally, radius of curvature of inclined edge portion 214 is smallest adjacent to front edge portion 213 and/or greatest adjacent to a vertex 215 of inclined edge portion 214, and it optionally increases gradually between front edge portion 213 and vertex 215, optionally particularly from front edge portion 213 to vertex 215. In some embodiments, inclined edge portion 214 forms a tangential angle with longitudinal axis X smaller than about 20° adjacent to vertex 215 thereof, and/or another tangential angle with longitudinal axis X greater than about 450 adjacent to its merging portion with front edge portion 213.
In some embodiments, catheter 201 is configured to engage an inner surface of a blood vessel with inclined edge portion 214 when pushed over access needle 202, and to slide with inclined edge portion 214 distally on the inner surface of the blood vessel when catheter tip 204 is pressed against the blood vessel wall when access needle 202 is withdrawn from catheter tip 204. Prior art catheters comprising a flat front end with no significant inclining and/or curved portions can be prone to harming blood vessel wall with a bottom edge thereof acting as a sharp edge, when the catheter engages and being pushed against the blood vessel wall while being inclined relative to the blood vessel long axis. Using a curved inclined edge portion 214 can overcome this disadvantage by first reducing likelihood of harming or penetrating blood vessel wall by reducing or eliminating sharpness and/or by possessing a greater footprint area engaging the blood vessel wall. Furthermore, it can distribute a greater tangential force component in the longitudinal direction of the blood vessel lumen and a smaller normal force component directed perpendicularly towards blood vessel wall from the force applied to push the catheter, relative to prior art catheters, since that tangent of the curved inclined edge portion 214 at some or all points of contact with blood vessel wall is parallel or close to parallel to blood vessel longitudinal direction. It should be noted that distal edge 208 is not fully inclined and/or curved, so that it includes a significantly sized front edge portion 213 for preserving sufficient structural integrity of catheter tip 204 during penetration through skin tissue and/or into a blood vessel on access needle 202 in the tissue-penetration configuration.
Inclined edge portion 214 includes or merges with a sliding surface 217. Sliding surface 217 is optionally at least partially curved and/or flat, and is at least partially parallel, or inclined at a shallow angle (e.g., smaller than 45°, optionally particularly smaller than 20°), to inclined edge portion 214 and/or to longitudinal axis X. Sliding surface 217 forms a shaped area bounded by and between a distal parabola 218 and a proximal parabola 219, such that distal parabola 218 has a smaller focal length than proximal parabola 219. In some embodiments, when kit 200 is assembled in the tissue-penetration configuration, needle edge 211 has an equal or greater distance to vertex 215 of inclined edge portion 214 (which is the vertex of distal parabola 218) than to a vertex 216 of front edge portion 213, shown in FIG. 2C. In some embodiments, catheter tip 204 varies in thickness along sliding surface 217, and sliding surface 217 has an average radius of curvature substantially greater than a radius of an outer surface portion of catheter tip opposing sliding surface 217 in a mutual transverse cross section. In some embodiments, sliding surface 217 has elastic resistance to inward radial deformation smaller than an opposing potion (along the top end) of the catheter tip 204. In some embodiments, kit 200 is configured such that catheter tip 204, along a bottom portion or end thereof, when radially inwardly collapsed, has a footprint on a surface of a blood vessel wall greater in size than a maximal sized lesion formable in the blood vessel wall by access needle 202.
Besides preventing harm to blood vessel wall by engaging the blood vessel inner surface with the curved inclined edge portion 214, catheter tip 204 is optionally also configured to reduce likelihood to increase size and/or severity of a lesion already caused such as by unintentional blood vessel wall penetration with sharp needle edge 211, when kit 200 is fixated at the tissue-penetration configuration, such as by expanding puncture size and/or advancing catheter 201 through this puncture out of blood vessel lumen. Inclined edge portion 214 includes two curved surfaces 220 provided at opposite sides of opening 209 relative to longitudinal axis X, each one of sliding surfaces 220 distinctly merges with front edge portion 213 at a different merging portion 221. This way, when catheter tip 204 engages a preformed lesion, the initial contact and sliding across the lesion will occur directly with the siding surfaces 220 that are more distant than the lesion width (being equal to or smaller than diameter of access needle 202). Each merging portion 221 is optionally rounded, curved and/or inclined, and is optionally located adjacent to or below longitudinal axis X.
FIGS. 4A-4E schematically illustrate a first set of exemplary scenarios representing steps in a method for accessing (inserting catheter 201 into) blood vessel BV using kit 200. As shown in FIG. 4A, catheter 201 and access needle 202 of kit 200 are first assembled and fixated together in the tissue-penetration configuration, and then pushed through skin layers of a live subject until penetrating blood vessel BV with beveled tip 203 to allow blood drawing into access needle 202 from blood vessel BV. Size of kit 200 is determined according to blood vessel dimensions so that by correctly positioning beveled tip 203 in lumen of blood vessel BV in the tissue-penetration configuration, catheter tip 204 is inserted (e.g., mostly or fully) into blood vessel BV as well. Catheter insertion can include verifying that bottom portion of opening 20) or catheter tip 204 is directed towards blood vessel BV, and/or that top portion of opening 209 or catheter tip 204 is directed away from blood vessel BV, for indicating correct positioning and orientation. When properly penetrating through skin and into blood vessel BV, for example as shown, top portion of front edge portion 213 functions as catheter's leading edge while inclined edge portion 214 is sufficiently remote proximally so as to diminish or avoid significant contribution to physical interaction with surrounding tissues during catheter insertion relative to contribution of front edge portion 213.
Once beveled tip 203 is in lumen of blood vessel BV, the medical practitioner can verify blood is drawn from blood vessel BV into access needle 202 which can indicate proper positioning of beveled needle 203. Following that, catheter 201 and access needle 202 can be shifted to the safety configuration (as shown in FIG. 4B) such as by moving beveled tip 203 relative to catheter tip 204 wherein beveled tip 203 fully resides within lumen 206 proximally to catheter distal end 207. This shifting step can follow or include change of inclination of catheter 201 with access needle 202 relative to blood vessel BV and/or repositioning of catheter 201 and/or access needle 202 in blood vessel BV.
When in the safety configuration, the medical practitioner can verify that blood is drawn from blood vessel BV into lumen 206 of catheter 201 before proceeding to complete its deployment. Then, access needle 202 can be further withdrawn and/or catheter 201 can be pushed forward (distally) over needle 202, and this can include engaging an inner (e.g., deeper) surface of blood vessel BV with inclined edge portion 214, as shown in FIG. 4C. Access needle 202 can be removed completely from lumen 206 and optionally replaced with a fluid source such as syringe connectable to catheter 201 with coupling means 212, which may be used to flush the catheter and/or to administer medication into blood vessel BV via catheter 201. Access needle 202 removal and/or syringe coupling can be performed while compressing blood vessel BV distally to catheter tip 204, as shown in FIG. 4D. Catheter 201 can then be advanced distally in the blood vessel (FIG. 4E) to final positioning and deployment.
FIGS. 5A-5F schematically illustrate a second set of exemplary scenarios representing steps in a method for accessing blood vessel BV using kit 200. In this set of scenarios, the medical practitioner can knowingly (e.g., intentionally) or unknowingly push the access needle 202 with catheter 201 in the tissue-penetration configuration across entire width of blood vessel BV such that beveled tip 203 penetrates both a top (shallow) portion and an opposing bottom (deep) portion of blood vessel BV, as shown in FIG. 5A for example. In this example, inserting catheter tip 204 into blood vessel BV when in the tissue-penetration configuration includes or results in forming a lesion LS through the inner surface of blood vessel BV wall with beveled tip 203 (shown in FIG. 5C, for example). Afterwards, catheter 201 can be withdrawn back into lumen of blood vessel BV until reaching and/or validating correct positioning before proceeding to final deployment stages of catheter 201 in blood vessel BV. Before withdrawing catheter 201, access needle 202 can be partially withdrawn (e.g., to the safety configuration) or fully withdrawn (e.g., removed) from catheter 201.
Following the ‘through-and-through’ penetration of blood vessel BV as shown in FIG. 5A, the medical practitioner can first verify if blood is drawn from blood vessel BV into access needle 202, although in this scenario the verifying can result in annulling that blood was drawn into the access needle (i.e., indicating or proving that no blood was actually drawn from blood vessel BV into access needle 202). With such a result, catheter 201 and access needle 202 can first be shifted to the safety configuration (FIG. 5B), or alternatively access needle 202 is removed from catheter 201, and then catheter 201 can be gradually withdrawn optionally with access needle 202 maintained in the safety configuration (FIG. 5C), until verifying blood is drawn from blood vessel BV into lumen 206 (indicating or proving that catheter tip 204 has been inserted into blood vessel BV). Catheter 201 can then be pushed and engage the inner surface of blood vessel BV with inclined edge portion 214 (FIG. 5D), optionally by sliding over remote portions of the inner surface of blood vessel BV from opposite sides of lesion LS with sliding surfaces 220 of inclined edge portion 214, for passing across lesion LS without penetrating again therethrough or harming surrounding tissue. If not already done at an earlier stage, access needle 202 can be completely removed from lumen 206 of catheter 201 (FIG. 5E), and catheter 201 can be advanced distally to a chosen deployment positioning (FIG. 5F). Advancement of catheter 201 can optionally include sliding over and across lesion LS with inclined edge portion 214 and/or catheter tip 204 along a bottom end thereof including with sliding surface 217.
In some embodiments, an advantage of using catheter 201 and/or kit 200 can be particularly met for accessing diseased or very small veins. In a small vein the diameter at the access point may be about the size the catheter body or even smaller, therefore at any given time along the access and deployment process there can be at least some engagement by a distal edge or portion of a prior art catheter tip with the blood vessel wall. By applying catheter 201 having inclined edge portion 214, this results in a smaller relative height than with standard catheter during inclined penetrations into the blood vessel. In some such embodiments, a preliminary step in a method for using kit 200 to deploy catheter 201 may include verifying that the blood vessel is diseased and/or is a vein equal to or smaller in diameter than catheter body or than about 1 mm.
FIG. 6A-6B illustrate, respectively, a side cross-sectional view and an isometric view of a portion of frontal tip 301 of a vascular access catheter 300. Catheter 300 may be an exemplary configuration and/or similar in at least one structural and/or functional feature to catheter 100 and/or catheter 201. Catheter 300 includes an elongated tubular catheter body 302 which encloses a lumen 303. Lumen 303 is cylindrical along a portion of catheter body 302 proximally to catheter tip 301, and tapers distally along a portion of catheter tip 301. Catheter body 302 has a plane of symmetry coinciding with a median plane MP that includes a longitudinal axis X of lumen 303. Catheter tip 301 which is formed as the distal part of catheter body 302 ends with a catheter distal end 304 and comprises a distal edge 305 at catheter distal end 304. Distal edge 305 surrounds an opening 306 which is opened to lumen 303. Distal edge 305 includes a pair of lateral leading edges 307 located at opposing sides of the median plane MP, each of the lateral leading edges 307 is curved downwardly and proximally from a respective front portion 308 of distal edge 305. Distal edge 305 further includes a bottom edge portion 309, extending between and below the lateral leading edges 307 and spanning a bottom portion of opening 306, and a top edge portion 310 extending between and above the lateral leading edges 307 and spanning a top portion of opening 306. In some embodiments, bottom edge portion 309 is curved generally proximally, and top edge portion 310 is substantially flat or uncurved.
Lateral leading edges 307 are configured to penetrate through an aperture in a bodily tissue and to gradually expand the aperture downwardly in parallel to median plane MP, when catheter tip 301 is pushed distally through the aperture, before bottom edge portion 309 penetrates through the aperture. In some embodiments, catheter 300 is particularly configured for accessing a blood vessel such as a peripheral vein using a kit (similar to kit 200 shown in FIG. 2A, for example) that also includes an access needle (similar to needle 202 shown in FIG. 2A, for example) and is configured for penetrating into the blood vessel when connected over the access needle, with the tip of the needle projecting distally via opening 306 form catheter 301. In some such embodiments, the bodily tissue is a skin tissue, and the catheter tip 301 is configured to pass through the aperture into the blood vessel over the access needle after the aperture is formed by the access needle. Catheter 300 with lateral leading edges 307 is configured for gradually stretching the skin tissue while expanding the aperture for reducing pain associated with catheter penetration through skin into a blood vessel over a needle, and unlike common over-the-needle vascular access catheters, which have a flat vertical front tips, the stretching of the skin is gradual and begins by lateral expansion using lateral leading edges 307 until full expansion with bottom edge portion 309 and top edge portion 310. When pushed through the aperture at an acute angle, relative to an outer surface of the bodily tissue, the lateral leading edges 307 penetrate through the aperture before bottom edge portion 309 and top edge portion 310.
Radius of curvature of each of the lateral leading edges 307 may be smallest adjacent to the respective front portion 308 and/or greatest adjacent to bottom edge portion 309, and/or it optionally increases gradually between the respective front portion 308 and bottom edge portion 309. In some other embodiments, the radius of curvature may vary differently or even in opposite direction, or be substantially constant along some or all periphery of each of lateral leading edges 307. Bottom edge portion 309 includes or merges with a sliding surface 311, which is inclined at a shallow angle relative to bottom edge portion 309. Sliding surface 311 is at least partially curved and forms a shaped area bounded by and between a distal parabola 312 and a proximal parabola 313, the distal parabola 312 has a smaller focal length than the proximal parabola 313.
FIG. 7A-7B illustrate, respectively, a side cross-sectional view and an isometric view of a portion a frontal tip 401 of vascular access catheter 400. Catheter 400 may be an exemplary configuration and/or similar in at least one structural and/or functional feature to catheter 100 and/or catheter 201. Catheter 400 includes an elongated tubular catheter body 402 which encloses a lumen 403. Lumen 403 is cylindrical along a portion of catheter body 402 proximally to catheter tip 401, and tapers distally along a portion of catheter tip 401. Catheter body 402 has a plane of symmetry coinciding with a median plane MP that includes a longitudinal axis X of lumen 403.
Catheter tip 401 which is formed as the distal part of catheter body 402 ends with a catheter distal end 404 and comprises a distal edge 405 at catheter distal end 404. Distal edge 405 surrounds an opening 406 which is opened to lumen 403. Distal edge 405 includes a pair of lateral leading edges 407 located at opposing sides of the median plane MP, each of the lateral leading edges 407 is curved downwardly and proximally, and upwardly and proximally, from a respective front portion 408 of distal edge 405. Distal edge 405 further includes a bottom edge portion 409, extending between and below the lateral leading edges 407 and spanning a bottom portion of opening 406, and a top edge portion 410 extending between and above the lateral leading edges 407 and spanning a top portion of opening 406. In some embodiments, each one of bottom edge portion 409 and top edge portion is curved generally proximally. In some embodiments, bottom edge portion 409 is greater in radius of curvature than top edge portion 410.
Lateral leading edges 407 are configured to penetrate through an aperture in a bodily tissue and to gradually expand the aperture downwardly in parallel to median plane MP, when catheter tip 401 is pushed distally through the aperture, before bottom edge portion 409 penetrates through the aperture. In some embodiments, catheter 400 is particularly configured for accessing a blood vessel such as a peripheral vein using a kit (similar to kit 200 shown in FIG. 2A, for example) that also includes an access needle (similar to needle 202 shown in FIG. 2A, for example) and is configured for penetrating into the blood vessel when connected over the access needle, with the tip of the needle projecting distally via opening 406 form catheter 401. In some such embodiments, the bodily tissue is a skin tissue, and the catheter tip 401 is configured to pass through the aperture into the blood vessel over the access needle after the aperture is formed by the access needle. Catheter 400 with lateral leading edges 407 is configured for gradually stretching the skin tissue while expanding the aperture for reducing pain associated with catheter penetration through skin into a blood vessel over a needle, and unlike common over-the-needle vascular access catheters, which have a flat vertical front tips, the stretching of the skin is gradual and begins by lateral expansion using lateral leading edges 407 until full expansion with bottom edge portion 409 and top edge portion 410. When pushed through the aperture at an acute angle, relative to an outer surface of the bodily tissue, the lateral leading edges 407 penetrate through the aperture before bottom edge portion 409 and top edge portion 410.
Radius of curvature of each of the lateral leading edges 407 may be smallest adjacent to the respective front portion 408 and/or greatest adjacent to bottom edge portion 409, and/or it optionally increases gradually between the respective front portion 408 and bottom edge portion 409. In some other embodiments, the radius of curvature may vary differently or even in opposite direction, or be substantially constant along some or all periphery of each of lateral leading edges 407. Bottom edge portion 409 includes or merges with a sliding surface 411, which is inclined at a shallow angle relative to bottom edge portion 409. Sliding surface 411 is at least partially curved and forms a shaped area bounded by and between a distal parabola and a proximal parabola, the distal parabola has a smaller focal length than the proximal parabola.
FIGS. 8A-8C schematically illustrate a set of exemplary scenarios representing steps in a method for penetrating a blood vessel using catheter 300 or catheter 400. Catheter 300 (or 400) is optionally as part of a kit that also includes an access needle 500 comprising a beveled tip 502 ending with a distal sharp needle edge 503. The kit may be similar to kit 200 shown in FIG. 2A, and/or optionally include coupling means configured to fixedly connect catheter body to access needle in a chosen orientation and axial travel of catheter 300 (or 400) relative to beveled tip 502. In some embodiments, when catheter 300 is properly fixedly connected to access needle 500, beveled tip 502 protrudes distally from lumen 303 through opening 306, such that a plane of symmetry of access needle 500 coincides with median plane MP, and beveled tip 502 is inclined distally and downwardly towards distal sharp needle edge 503 from a top needle end 504 extending through catheter's 300 opening top portion to a bottom needle end 505 extending through catheter's 300 opening bottom portion. In some embodiments, catheter 300 (or 400) is configured to accommodate access needle 500 through lumen 303 and opening 306 in at least two configurations comprising: (a) a tissue-penetration configuration wherein beveled tip 502 fully extends from lumen 303 distally to catheter distal end 304 (similar to as shown in FIG. 4A, for example), and (b) a safety configuration wherein beveled tip 502 fully resides within lumen 303 proximally to catheter distal end 304 (similar to as shown in FIG. 4B, for example).
FIG. 8A shows a first scenario in which catheter 300 is properly fixedly connected in the tissue-penetration configuration, and after the assembled kit was applied for forming an aperture with beveled tip 502 in a skin tissue covering a blood vessel (e.g., a peripheral vein). In FIG. 8A, drawing (I) shows a side cross-sectional view (parallel to median plane MP) of a portion of a human body showing a blood vessel BV covered with layers of skin tissue SK, and drawing (II) shows a frontal cross-sectional view (perpendicular to median plane MP) of skin tissue SK at the same instance of drawing (I), when skin tissue SK is partially penetrated by with beveled tip 502. As shown, beveled tip 502 forms an aperture AP by first cutting a generally horizontal cut (e.g., transverse to catheter tip 301 and perpendicular to median plane MP) and then expanding it gradually when beveled tip 502 is advanced distally through aperture AP.
When catheters provided over an access needle are then forced to penetrate through the aperture formed in a skin tissue, the sudden increase in diameter forces the skin surrounding the aperture to stretch open immediately and this is associated with increased pain to the subject (patient), particularly when the aperture is forced to immediately expand perpendicularly to the initial cut direction (e.g., parallel to median plane MP). By using catheter 300, expansion of aperture AP is more gradual, and the skin tissue SK is first stretched generally parallel to the initial cut with the lateral leading edges 307 and then after the skin is stretched gradually downwardly (and optionally upwardly afterwards) parallel to median plane MP and perpendicularly to initial cut direction. FIG. 8B shows a second scenario in which catheter body 302 is pushed and partially advanced distally through aperture AP, after beveled tip 502 is fully advanced therethrough and initially penetrated blood vessel BV, and lateral leading edges 307 of catheter 300 are partially penetrating aperture AP.
FIG. 8C shows a third scenario in which catheter body 302 is further advanced distally through aperture AP. Now aperture AP is expanded in all directions by catheter distal tip 301 after bottom edge portion 309 and top edge portion 310 have also penetrated therethrough and also into blood vessel BV. Due to the curving of each of lateral leading edges downwardly and proximally, in parallel to median plane MP, towards bottom edge portion 309, downward expansion of skin tissue SK surrounding aperture AP is gradual and optionally less painful. In some embodiments, top edge portion 310 penetrates through aperture AP following full or partial penetration of bottom edge portion 309. Inserting beveled tip 502 and/or catheter tip 301 into blood vessel BV causes blood to be drawn from blood vessel BV into access needle 500 and/or catheter body 302, which can be visualized and indicate about catheter 300 positioning to the operator. At this stage, the operator can push catheter body 302 distally relative to access needle 500, optionally by changing kit configuration to the safety configuration, and remove access needle 500 from blood vessel BV, optionally similarly or identically to as shown and described with respect to FIGS. 4A-4E. Alternatively, the operator can apply additional steps, optionally similarly or identically to as shown and described with respect to FIGS. 5A-5F, at least in part. For example, after inserting beveled tip 502 and/or catheter tip 301 into blood vessel BV, access needle 500 can be applied to penetrate across a wall of the blood vessel, such that beveled tip 502 protrudes distally from blood vessel BV (at this stage, blood no longer flows through access needle 500 out of patient body and this can serve as an indicator for moving across and out of blood vessel BV). Beveled tip 502 can then be drawn back into blood vessel BV until visualizing blood is drawn again into access needle 500 and/or catheter body 302. Then catheter body 302 can be pushed distally relative to access needle 500, and access needle 500 can be removed from blood vessel BV.
Each of the following terms written in singular grammatical form: ‘a’, ‘an’, and ‘the’, as used herein, means ‘at least one’, or ‘one or more’. Use of the phrase ‘one or more’ herein does not alter this intended meaning of ‘a’ ‘an’, or ‘the’. Accordingly, the terms ‘a’. ‘an’, and ‘the’, as used herein, may also refer to, and encompass, a plurality of the stated entity or object, unless otherwise specifically defined or stated herein, or, unless the context clearly dictates otherwise. For example, the phrases: ‘a unit’, ‘a device’, ‘an assembly’, ‘a mechanism’. ‘a component’. ‘an element’, and ‘a step or procedure’, as used herein, may also refer to, and encompass, a plurality of units, a plurality of devices, a plurality of assemblies, a plurality of mechanisms, a plurality of components, a plurality of elements, and, a plurality of steps or procedures, respectively.
Each of the following terms: ‘includes’, ‘including’, ‘has’, ‘having’, ‘comprises’, and ‘comprising’, and, their linguistic/grammatical variants, derivatives, or/and conjugates, as used herein, means ‘including, but not limited to’, and is to be taken as specifying the stated component(s), feature(s), characteristic(s), parameter(s), integer(s), or step(s), and does not preclude addition of one or more additional component(s), feature(s), characteristic(s), parameter(s), integer(s), step(s), or groups thereof. Each of these terms is considered equivalent in meaning to the phrase ‘consisting essentially of’.
The term ‘method’, as used herein, refers to steps, procedures, manners, means, or/and techniques, for accomplishing a given task including, but not limited to, those steps, procedures, manners, means, or/and techniques, either known to, or readily developed from known steps, procedures, manners, means, or/and techniques, by practitioners in the relevant field(s) of the disclosed invention.
Throughout this disclosure, a numerical value of a parameter, feature, characteristic, object, or dimension, may be stated or described in terms of a numerical range format. Such a numerical range format, as used herein, illustrates implementation of some exemplary embodiments of the invention, and does not inflexibly limit the scope of the exemplary embodiments of the invention. Accordingly, a stated or described numerical range also refers to, and encompasses, all possible sub-ranges and individual numerical values (where a numerical value may be expressed as a whole, integral, or fractional number) within that stated or described numerical range. For example, a stated or described numerical range ‘from 1 to 6’ also refers to, and encompasses, all possible sub-ranges, such as ‘from 1 to 3’, ‘from 1 to 4’, ‘from 1 to 5’, ‘from 2 to 4’, ‘from 2 to 6’, ‘from 3 to 6’, etc., and individual numerical values, such as ‘1’, ‘1.3’. ‘2’, ‘2.8’, ‘3’, ‘3.5’, ‘4’. ‘4.6’, ‘5’, ‘5.2’, and ‘6’, within the stated or described numerical range of ‘from 1 to 6’. This applies regardless of the numerical breadth, extent, or size, of the stated or described numerical range.
Moreover, for stating or describing a numerical range, the phrase ‘in a range of between about a first numerical value and about a second numerical value’, is considered equivalent to, and meaning the same as, the phrase ‘in a range of from about a first numerical value to about a second numerical value’, and, thus, the two equivalently meaning phrases may be used interchangeably. For example, for stating or describing the numerical range of room temperature, the phrase ‘room temperature refers to a temperature in a range of between about 20° C. and about 25° C.’, and is considered equivalent to, and meaning the same as, the phrase ‘room temperature refers to a temperature in a range of from about 20° C. to about 25° C.’.
The term ‘about’, as used herein, refers to ±10% of the stated numerical value.
It is to be fully understood that certain aspects, characteristics, and features, of the invention, which are, for clarity, illustratively described and presented in the context or format of a plurality of separate embodiments, may also be illustratively described and presented in any suitable combination or sub-combination in the context or format of a single embodiment. Conversely, various aspects, characteristics, and features, of the invention which are illustratively described and presented in combination or sub-combination in the context or format of a single embodiment, may also be illustratively described and presented in the context or format of a plurality of separate embodiments.
Although the invention has been illustratively described and presented by way of specific exemplary embodiments, and examples thereof, it is evident that many alternatives, modifications, or/and variations, thereof, will be apparent to those skilled in the art. Accordingly, it is intended that all such alteratives, modifications, or/and variations, fall within the spirit of, and are encompassed by, the broad scope of the appended claims.
All publications, patents, and or/and patent applications, cited or referred to in this disclosure are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent, or/and patent application, was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this specification shall not be construed or understood as an admission that such reference represents or corresponds to prior art of the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.

Claims

What is claimed is:

1. A vascular access catheter, comprising:

an elongated tubular catheter body enclosing a lumen, the catheter body has a plane of symmetry coinciding with a median plane and includes a catheter tip ending with a catheter distal end and comprising a distal edge at the catheter distal end surrounding an opening opened to the lumen, the distal edge includes: (a) a pair of lateral leading edges located at opposing sides of the median plane, each of the lateral leading edges is curved downwardly and proximally from a respective front portion of the distal edge, (b) a bottom edge portion extending between and below the lateral leading edges and spanning a bottom portion of the opening, and (c) a top edge portion extending between and above the lateral leading edges and spanning a top portion of the opening;

wherein the lateral leading edges are configured to penetrate through an aperture in a bodily tissue and to gradually expand the aperture downwardly in parallel to the median plane, when the catheter tip is pushed distally through the aperture, before the bottom edge portion penetrates through the aperture.

2. The vascular access catheter according to claim 1, wherein the bodily tissue is a skin tissue, and the catheter tip is configured to pass through the aperture into a blood vessel over an access needle after the aperture is formed by the access needle.

3. The vascular access catheter according to claim 2, configured for gradually stretching the skin tissue while expanding the aperture for reducing pain associated with catheter penetration through skin into a blood vessel over a needle.

4. The vascular access catheter according to claim 1, wherein the bottom edge portion and/or the top edge portion is curved generally proximally.

5. The vascular access catheter according to claim 1, configured such that the lateral leading edges penetrate through the aperture before the bottom edge portion and the top edge portion, when pushed through the aperture at an acute angle relative to an outer surface of the bodily tissue.

6. The vascular access catheter according to claim 1, wherein each of the lateral leading edges is curved upwardly and proximally from the respective front portion of the distal edge.

7. The vascular access catheter according to claim 1, wherein the lumen is cylindrical along a portion of the catheter body proximally to the catheter tip and tapers along a portion of the catheter tip.

8. The vascular access catheter according to claim 1, wherein radius of curvature of each of the lateral leading edges is smallest adjacent to the respective front portion and/or greatest adjacent to the bottom edge portion.

9. The vascular access catheter according to claim 1, wherein radius of curvature of each of the lateral leading edges gradually increases between the respective front portion and the bottom edge portion.

10. The vascular access catheter according to claim 1, wherein the bottom edge portion includes or merges with a sliding surface, the sliding surface is at least partially parallel, or inclined at a shallow angle, to the bottom edge portion.

11. The vascular access catheter according to claim 10, wherein the sliding surface forms a shaped area bounded by and between a distal parabola and a proximal parabola, the distal parabola has a smaller focal length than the proximal parabola.

12. The vascular access catheter according to claim 10, wherein the sliding surface is at least partially curved.

13. A vascular access kit, comprising:

the vascular access catheter according to claim 1, and

an access needle comprising a beveled tip ending with a distal sharp needle edge.

14. The kit according to claim 13, comprising coupling means configured to fixedly connect the catheter body to the access needle, wherein the beveled tip protrudes distally from the lumen through the opening, such that a plane of symmetry of the access needle coincides with the median plane and the beveled tip is inclined distally and downwardly towards the distal sharp needle edge from a top needle end extending through the opening top portion to a bottom needle end extending through the opening bottom portion.

15. The kit according to claim 14, wherein the catheter is configured to accommodate the access needle through the lumen and the opening in at least two configurations comprising a tissue-penetration configuration wherein the beveled tip fully extends from the lumen distally to the catheter distal end, and a safety configuration wherein the beveled tip fully resides within the lumen proximally to the catheter distal end.

16. A method for inserting a catheter into a blood vessel using the kit of claim 13, the method comprising:

providing the vascular access catheter connected to the access needle, wherein the beveled tip protrudes distally from the lumen through the opening, such that a plane of symmetry of the access needle coincides with the median plane and the beveled tip is inclined distally and downwardly towards the distal sharp needle edge from a top needle end extending through the opening top portion to a bottom needle end extending through the opening bottom portion;

forming an aperture in a skin tissue covering the blood vessel with the beveled tip;

pushing the catheter body through the aperture at an acute angle relative to an outer surface of the skin tissue, thereby expanding the aperture sideways perpendicularly to the median plane with the pair of lateral leading edges followed by gradually expanding the aperture downwardly in parallel to the median plane until the bottom edge portion penetrates through the aperture.

17. The method according to claim 16, wherein the top edge portion penetrates through the aperture following full or partial penetration of the bottom edge portion.

18. The method according to claim 16, comprising inserting the beveled tip and/or the catheter tip into the blood vessel until visualizing blood drawn from the blood vessel into the access needle and/or the catheter body.

19. The method according to claim 18, wherein the inserting is followed by pushing the catheter body distally relative to access needle and removing the access needle from the blood vessel.

20. The method according to claim 18, wherein the inserting is followed by penetrating across a wall of the blood vessel such that the beveled tip protrudes distally from the blood vessel, then drawing the beveled tip back into the blood vessel until visualizing blood drawn from the blood vessel into the access needle and/or the catheter body, and then pushing the catheter body distally relative to access needle and removing the access needle from the blood vessel.