Apparatus and method for cannula insertion into vascular access grafts

Abstract

To provide an excellent apparatus.SOLUTION: There is provided an apparatus for guiding cannulation with a dialysis needle of an arteriovenous dialysis access graft subcutaneously implanted in a body of a subject. The guiding apparatus comprises an elongated body member comprising a base portion terminating in longitudinal edges, a distance between the longitudinal edges of the base portion being substantially equal to a lateral dimension of the aces graft, and an elongated tubular sleeve defining a pocket having a longitudinal dimension and a lateral dimension configured to receive the body member. The body member is adapted to be received in the pocket of the sleeve for securing adjacent the subcutaneous access graft such that the inner surface of the base portion is aligned with a cannulation point of the graft for guiding location of a needle insertion.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] [Cross-reference]

[0002] This application is related to U.S. Provisional Patent Application No. 62 / 479,791, filed Mar. 31, 2017, entitled "Apparatus and Method for Cannula Insertion in a Vascular Access Graft", naming Shawn M. Gage and Jeffrey H. Lawson as inventors. The content of this U.S. provisional patent application is hereby incorporated by reference in its entirety, and the benefit of the filing date of this U.S. provisional patent application is hereby claimed for all purposes legally served by such claims regarding the benefit of the filing date.

[0003] Disclosed are an apparatus and method for needle access of surgically created vascular access for use as a means of receiving hemodialysis and other procedures requiring vascular access, more specifically, an apparatus and method for vascular access of an arteriovenous graft or arteriovenous fistula that enables positioning of a cannulation site after transplantation.

Background Art

[0004] Hemodialysis is a life-sustaining treatment for patients with end-stage renal disease. Hemodialysis is a process in which a large volume of blood is removed from the body, filtered through a machine that removes waste products, and then returned to the body.

[0005] The vascular access sites on the body from which blood will be drawn and returned during dialysis are prepared before hemodialysis begins. The creation of an arteriovenous fistula ("AVF") is achieved by a surgical procedure in which a vein is directly connected to an artery. The connection between artery and vein can be formed using an arteriovenous graft ("AVG") made from synthetic material and implanted just beneath the skin. Placement sites for AVGs include, but are not limited to, the forearm, upper arm, neck, chest, and thigh, in either a linear or loop configuration. Once surgically positioned, the AVG becomes a conduit that can be repeatedly used for blood access during hemodialysis. Needles are used to cannulate the graft through the skin and to directly puncture the graft wall. In conventional hemodialysis, two cannulas are placed in the access graft, with one needle puncture made in the graft wall on the arterial side and the other needle puncture made on the venous side. During dialysis, blood is drawn from the arterial side of the graft, passes through the hemodialysis machine, and is then returned to the patient through a second needle inserted into the venous side of the graft.

[0006] A crucial step in hemodialysis procedures is "finding" the correct location within the graft for needle puncture. Furthermore, conventional dialysis protocols require patients to undergo dialysis procedures at least three times a week. As a result, the skin and underlying tissues are punctured multiple times a week to gain access to the transplanted AVG. The technique of cannulating an AVF or AVG for hemodialysis requires considerable skill. Vascular access is often located several centimeters below the surface of the skin and cannot be located by visual inspection. Medical technicians are required to locate the AVF or AVG by palpation, which can be extremely difficult. Puncture of vascular access is prone to errors and complications. Inaccurate punctures can facilitate rupture of the access, bleeding, hematoma formation, pseudoaneurysm formation, severe pain, or the development of organized thrombi within the lumen of the graft. The formation of such blood clots can not only lead to multiple graft thrombosis but can also ultimately result in graft failure. Complete lack of vascular access or improper positioning of the needle within the lumen of the AVF or AVG device are two contraindications that negatively impact the time the graft remains available. Positioning the cannula insertion site simply by using conventional methods of palpation through the skin may be unreliable. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] U.S. Patent No. 9,585,998 [Patent Document 2] U.S. Publication Application No. 2014 / 0336682 Specification [Patent Document 3] U.S. Patent No. 4,268,983 [Patent Document 4] U.S. Patent No. 5,358,281 [Patent Document 5] U.S. Patent No. 4,121,003 [Patent Document 6] U.S. Patent No. 5,633,058 [Non-patent literature]

[0008] [Non-Patent Document 1] Ji et al. (2007) [Overview of the project] [Problems that the invention aims to solve]

[0009] For the reasons stated above, there is a need for devices and methods for proper cannula insertion of vascular access grafts or fistulas, including accurate identification of the access area of ​​vascular access after transplantation. Novel devices should improve access to transplanted AVF or AVG devices by enabling users of vascular access to easily and accurately and reproducibly insert dialysis needles and cannulas, etc., into the transplanted AVF or AVG through skin insertion. [Means for solving the problem]

[0010] The present invention provides a device for guiding cannula insertion using a dialysis needle from an arteriovenous dialysis access graft subcutaneously implanted in a subject's body. The arteriovenous dialysis graft includes a flexible conduit that defines a longitudinal flow path, having a first terminal portion configured to connect to the subject's artery and a second terminal portion configured to connect to the subject's vein, so that blood flows through the longitudinal flow path of the conduit from the first terminal portion to the second terminal portion. A cannula insertion chamber defines a cannula insertion port, and the conduit extends through the cannula insertion chamber to receive a needle inserted through the cannula insertion port. The guidance device includes an elongated body member having a longitudinal axis and an inner surface. The body member includes a base portion that terminates within its longitudinal edge. The distance between the longitudinal edges of the base portion is substantially equal to the lateral dimension of the cannula insertion chamber. Legs extend from the longitudinal edges of the base portion and terminate within the longitudinal edge. The base and legs define an open longitudinal channel for receiving the cannula insertion chamber. The main body is fixed adjacent to the subcutaneous cannula insertion chamber such that the legs operatively engage with the cannula insertion chamber to align the inner surface of the base with the cannula insertion port to guide the needle insertion site through the main body into the cannula insertion chamber.

[0011] In one embodiment, the main body member has a first end and a second end, and the main body member extends from the first end to the second end of the cannula insertion chamber. The main body member may have at least one passage that opens into the inner surface of the main body member for the needle to pass through.

[0012] In another embodiment, at least a portion of the cannula insertion chamber and the main body member includes a substantially magnetic or paramagnetic material.

[0013] In another embodiment, a device is provided for guiding cannula insertion using a dialysis needle of an arteriovenous dialysis access graft subcutaneously implanted in the body of a subject. The arteriovenous dialysis graft includes a flexible conduit having a first terminal portion configured to define a longitudinal flow path and connect to the subject's artery and a second terminal portion configured to connect to the subject's vein, so that blood flows through the longitudinal flow path of the conduit from the first terminal portion to the second terminal portion. A cannula insertion chamber is provided between the first and second terminal portions, with a cannula insertion port. The conduit is defined and extends through the cannula insertion chamber to receive the needle inserted through the cannula insertion port. The guide device includes an elongated tubular sleeve having a longitudinal axis. The sleeve defines an opening having longitudinal and transverse dimensions that are substantially equal to the longitudinal and transverse dimensions of the cannula insertion chamber. The sleeve is configured to accommodate the subject's body adjacent to the subcutaneous cannula insertion chamber of the access graft, such that the opening surrounds the cannula insertion chamber to guide the needle insertion site into the cannula insertion port.

[0014] In one embodiment, the material of the sleeve is selected from film, paper, woven fabric, or nonwoven fabric.

[0015] In yet another embodiment, a device is provided for guiding cannula insertion using a dialysis needle from an arteriovenous dialysis access graft subcutaneously implanted in a subject's body. The arteriovenous dialysis graft includes a flexible conduit having a first terminal portion configured to define a longitudinal flow path and connect to the subject's artery, and a second terminal portion configured to connect to the subject's vein, so that blood flows through the longitudinal flow path of the conduit from the first terminal portion to the second terminal portion. A cannula insertion chamber defines a cannula insertion port between the first and second terminal portions. The conduit extends through the cannula insertion chamber to receive a needle inserted through the cannula insertion port. The guidance device includes an elongated body member having a longitudinal axis and an inner surface. The body member includes a base portion terminating within its longitudinal edge, the distance between the longitudinal edges of the base portion being substantially equal to the lateral dimension of the cannula insertion chamber. An elongated tubular sleeve has a longitudinal axis, and the sleeve defines a pocket having longitudinal and lateral dimensions configured to receive the body member. The main body component is received into a sleeve pocket so as to be fixed adjacent to the subcutaneous cannula insertion chamber, with the inner surface of the base portion aligning with the cannula insertion port to guide the needle insertion point into the cannula insertion chamber through the main body component.

[0016] A kit is also provided and includes at least one dialysis needle for accessing an arteriovenous dialysis access graft that has been implanted subcutaneously into a subject's body. The arteriovenous dialysis graft includes a flexible conduit having a first end portion configured to define a longitudinal flow path and connect to an artery of the subject and a second end portion configured to connect to a vein of the subject, such that blood flows from the first end portion to the second end portion through the longitudinal flow path of the conduit. A cannula insertion chamber defines a cannula insertion port, and the conduit extends through the cannula insertion chamber to receive a needle inserted through the cannula insertion port. A dispensing container is provided for housing a plurality of elongated body members each having a longitudinal axis and an inner surface. The body members include a base portion that terminates within a longitudinal edge, and the distance between the longitudinal edges of the base portion is substantially equal to the lateral dimension of the cannula insertion chamber. The body members are fixed adjacent to the subcutaneous cannula insertion chamber such that legs operatively engage the cannula insertion chamber to align the inner surface of the base portion with the cannula insertion port to guide the location of needle insertion. Each body member has at least one passage opening into the inner surface of the body member for passing a needle, and the needle passage of each body member is in a different position than the needle passage of any other body member.

Brief Description of the Drawings

[0017] For a more complete understanding of the present invention, reference must now be made to the embodiments illustrated in the accompanying drawings and described below.

[0018] [Figure 1] FIG. 12 is an exploded perspective view of an embodiment of an applicator device for cannula insertion of an arteriovenous graft including a cannula insertion chamber; [Figure 2] FIG. 15 is a longitudinal cross-sectional view of the applicator device as shown in FIG. 12 in a position over the subcutaneous cannula insertion chamber; [Figure 3] FIG. 18 is a top and bottom perspective view, side and end elevational views, and top and bottom plan views of the applicator device as shown in FIG. 12. [Figure 4]Top and bottom perspective views, side and end elevations, and top and bottom plan views of a second embodiment of an applicator device for cannula insertion of an arteriovenous graft including a cannula insertion chamber as shown in FIG. 1. [Figure 5A] Perspective view of an embodiment of a portion of an arteriovenous graft including a cannula insertion chamber. [Figure 5B] Exploded perspective view of a third embodiment of an applicator device for cannula insertion of an arteriovenous graft including a cannula insertion chamber as shown in FIG. 5A. [Figure 6] Perspective view of a plurality of applicator devices through which successively spaced needle passages penetrate. [Figure 7] Perspective view of a plurality of applicator devices with needle passages angled obliquely through the applicator device as shown in FIG. 6. [Figure 8A] Perspective view of a dispensing cartridge for a packaged applicator device. [Figure 8B] Perspective view of a dispensing cartridge for a packaged applicator device. [Figure 9] Top plan view of an embodiment of a pair of adhesive applicator devices for guiding cannula insertion of an arteriovenous graft including a pair of cannula insertion chambers. [Figure 10] Top plan view of a pair of adhesive applicator devices as shown in FIG. 9 in a position on the upper arm including a subcutaneous arteriovenous graft including a pair of cannula insertion chambers. [Figure 11A] Perspective view of a fourth embodiment of an applicator device and sleeve for cannula insertion of an arteriovenous graft. [Figure 11B] Perspective view of a fourth embodiment of an applicator device and sleeve for cannula insertion of an arteriovenous graft. [Figure 12] Top plan view of an embodiment of an adhesive applicator device for guiding cannula insertion of a subcutaneous arteriovenous graft including each of a pair of cannula insertion chambers (not shown) for achieving hemodialysis. [Figure 13] This is a top plan view of an embodiment of a fragile adhesive applicator device for guiding cannula insertion into a subcutaneous arteriovenous graft, each of which includes a pair of cannula insertion chambers indicated by dashed lines. [Figure 14] This is a top plan view of another embodiment of a fragile adhesive applicator device for guiding cannula insertion into a subcutaneous arteriovenous graft, each of which includes a pair of cannula insertion chambers indicated by dashed lines. [Figure 15A] This is a perspective view of a flexible strap used for cannula insertion into subcutaneous arteriovenous grafts. [Figure 15B] This is an elevation view of a flexible strap used for cannula insertion into subcutaneous arteriovenous grafts. [Figure 16] This is a top plan view of a pair of straps, as shown in Figures 15A and 15B, positioned on an arm-mounted applicator device for guiding the insertion of a subcutaneous arteriovenous graft (not shown) via cannula. [Figure 17] This is a top plan view of a pair of straps, as shown in Figures 15A and 15B, positioned on the arm to guide the insertion of a subcutaneous arteriovenous graft, each containing a pair of cannula insertion chambers, indicated by dashed lines. [Figure 18] This is a top plan view of an embodiment of a sleeve positioned on the arm for guiding cannula insertion into a subcutaneous arteriovenous graft, each of which includes a pair of cannula insertion chambers indicated by dashed lines. [Figure 19] Figure 18 shows a close-up perspective view of a sleeve, indicating a pocket for receiving an applicator device to guide cannula insertion into a subcutaneous arteriovenous graft. [Figure 20] Figure 18 is a perspective view of a sleeve including the applicator device. [Modes for carrying out the invention]

[0019] As used herein, the term “vascular access” is used to mean the intended surgical connection between the arterial and venous systems through which blood flows from arteries to veins. As described above, this can be achieved by directly connecting veins to arteries (AVF) or by utilizing synthetic or autologous conduits to connect the arterial and venous systems (AVG). Since there are many types of AVGs and related components that are known in the art and can be used to carry out the present invention, a more detailed description of these components is not necessary. It is understood that the present invention is not directed to any particular type of AVG. The vascular access graft devices and methods described herein are for use in medical procedures requiring vascular access. Accordingly, the features described herein, but not limited to, can be used with any conventional vascular access graft of an AVG, including the AVG described in U.S. Patent No. 9,585,998, which is thus incorporated herein by reference in its entirety. Similar uses are illustrated and described in U.S. Patent Publication Application 2014 / 0336682, which is also incorporated herein by reference in its entirety. Therefore, a detailed explanation of all the functions of the components and the use of the grafts is considered unnecessary for those skilled in the art to understand the description of the present invention.

[0020] Certain technical terms are used herein merely for convenience and should not be taken as limiting. For example, words such as “upper,” “lower,” “left,” “right,” “horizontal,” “vertical,” “upward,” “downward,” “top,” and “bottom” simply describe the configuration shown in the diagram. In fact, components can be oriented in any direction, and it should be understood that technical terms therefore encompass such variations unless otherwise specified. The words “inside” and “outside” refer to directions toward and away from the geometric center of the core and its designated part, respectively. Technical terms include the words specifically mentioned above, their derivatives, and words with similar meanings.

[0021] Referring here to drawings where similar reference numbers correspond to or specify similar elements through several figures, a vascular access graft for connecting an artery to a vein is shown in Figure 1, the whole of which is designated 40. The vascular access graft 40 includes a tubular portion 42 of biocompatible material for guiding a fluid such as blood. Conventionally, the tubular portion 42 is anastomosed to an artery at a first end and to a vein at a second end (not shown). A pair of spaced-apart cannula insertion chambers 44 are positioned midway along the length of the tubular portion that fluidizes the arterial and venous sides of the vascular access graft 40.

[0022] An applicator device for use in identifying the needle insertion site for cannula insertion into the transplanted vascular access graft 40 is also shown in Figure 1, and is designated 50 overall. The applicator device 50 is adaptable to the cannula insertion chamber 44 of the vascular access graft 40, enabling highly localized and precise delivery of the needle into a predetermined portion of the cannula insertion chamber 44. The term “adaptable” as used herein includes any corresponding fixation or alignment means for positioning the application device 50 relative to the cannula insertion chamber 44. That is, it is understood that multiple means of adaptation are anticipated that can be used to align the applicator device to a wide range of vascular access grafts.

[0023] The applicator device can be formed from any synthetic or natural material, including, but not limited to, thermoplastics, thermosetting polymers, elastomers, rubber, or woven or nonwoven composite materials. The applicator device can be in any suitable molded form, such as polymer plastic foams (including open-cell foams), woven or nonwoven composite materials, or mixtures thereof. Particularly preferred applicator devices are, therefore, polyolefins such as nylon, polyethylene including UHMW polyethylene, PEEK (polyether ether ketone), polysulfone, polypropylene, ethylene, etc. The applicator devices can be prepared from polypropylene copolymers, ethylene butadiene copolymers, polyurethanes, polyurethane foams, polystyrene, plastic polyvinyl chloride, polyethylene, Delrin polyacetal, and polyamides, as well as homopolymers and the copolymers mentioned above. The applicator device can also be made of a gel-like substance that provides pressure for hemostasis when compressed. The applicator can be doped with one or more drugs to assist in the process of cannula insertion and / or needle removal. For example, lidocaine can be added to help minimize pain during needle puncture, and / or local hemostatic agents can be incorporated to help stop bleeding. Many combinations of drug combinations with the applicator can be anticipated. It is understood that the applicator device can take on various shapes as needed and can accept and adapt to various vascular access grafts and cannula insertion chambers. It is further understood that the needle passage can be provided in locations where the material of the applicator device is too rigid to allow penetration by the needle.

[0024] In one embodiment, the applicator device 50 can be configured to be adaptable to a graft vascular access graft 40 by being attached to the graft in a puzzle-piece manner. In this embodiment, the “attached” applicator device 50, as shown in Figure 3, is an elongated member having a substantially oval profile and a substantially main base portion 52 having a longitudinal axis. The base portion 52 spans between substantially planar side walls 54 or legs, two of which hang down from the longitudinal edges 53 on each side of the base portion 52. The legs 54 hang down substantially perpendicularly along the length of the edges 53 of the base portion 52. Each of the legs 54 terminates within the longitudinal edge 55. The base portion 52 and the legs 54 define an open longitudinal channel 56. Referring to Figures 1 and 2, the applicator device 50 having this configuration is adaptable to an AVG 40 which includes a cannula insertion chamber 44 having an upper circumferential rim 46 that defines spaced-out notches 48 for receiving the legs 54 of the applicator device 50. In use, the applicator device 50 is adapted to the AVG 40 by positioning the device over the cannula insertion chamber 44 so that the legs 54 engage with the notches 48 with the skin trapped between them. In this arrangement, the applicator device 50 indicates the position of the cannula insertion chamber 44, and the user can then select a desired location along the length of the cannula insertion chamber for needle insertion.

[0025] Referring to Figure 2, in use, the vascular access graft is implanted under the patient's skin with one end 59a implanted in an artery and the other end 59b implanted in a vein, thereby establishing fluid continuity from the artery through the lumen of the tubular element into the vein. In a method of hemodialysis for a patient using the vascular access graft 40, the lumen of the vascular access graft 40 is connected to the hemodiafiltration unit via a needle so that blood can be diverted from the lumen into the hemodiafiltration unit, filtered, and then returned to the lumen. It is understood that vascular access grafts may have uses other than dialysis. Such uses include situations in which the patient requires frequent intravenous injection or infusion of therapeutic fluids. In all cases, the use of applicator devices, stickers, straps, and sleeves greatly reduces the number of typically "missed" needle punctures and generally facilitates greater accuracy in identifying the implanted device into which needle cannula insertion is desired.

[0026] The applicator device 50 is manually positioned in the cannula insertion chamber 44 so that its legs 54 correspond to the notches 48 within the cannula insertion chamber 44. The applicator device 50 is then pressed toward the cannula insertion chamber 44 so that its legs 54 engage with the notches 48. During the downward movement of the device 50, the legs 54 are slidably received into the longitudinal notches 48 within the perimeter rim 46 of the cannula insertion chamber 44. The applicator device 50 is thus positioned such that the device is positioned above the cannula insertion chamber 44 as shown in Figure 1. The user then inserts one or more needles into the cannula insertion chamber 44 to begin hemodialysis. Needle insertion is facilitated so that the user can do it as quickly and accurately as possible with minimal blood loss and maximum benefit to the user.

[0027] Another embodiment of the “mounted” applicator device is shown in Figure 4, the whole of which is designated 60. As in the previous embodiment, the applicator device 60 is an elongated member having a substantially oval profile and includes a substantially main base portion 62 having a longitudinal axis. In this embodiment, the base portion 62 defines spaced-out notches 64 formed along the longitudinal edges on each side of the base portion 62. The applicator device 60 having this configuration is adaptable to an AVG 40 which includes a cannula insertion chamber 44 having legs (not shown) projecting outward from an upper circumferential rim 46 so as to be inserted into the spaced-out notches 64 of the applicator device 60. In use, the applicator device 60 is adapted to the AVG 40 by positioning the device on the cannula insertion chamber 44 so as to have legs that fit into the notches 64. In this arrangement, the applicator device 60 indicates the position of the cannula insertion chamber 44, and the user can then select a desired location along the length of the device for needle insertion.

[0028] In another embodiment, the vascular access graft 40 includes one or more fixably positioned magnetic, paramagnetic, or ferromagnetic materials 70 that generate one or more distinct sites on the cannula insertion chamber 44, as shown in Figure 5A. In the illustrated embodiment, the magnetic or paramagnetic sites are circumferentially arranged along the peripheral rim 46 on the upper surface of the cannula insertion chamber 44. This arrangement substantially defines the boundary of the port 47 of the cannula insertion chamber 44 configured to receive needle punctures. Following implantation, the cannula insertion chamber 44 can be positioned within the patient's body by passing a magnet across the patient's skin surface near the implantation site, thereby allowing the magnet to essentially identify the optimal site for needle access or puncture of the vascular access graft during cannula insertion.

[0029] A locator or detector (not shown) containing one or more magnets can be used to position the graft and identify the cannula insertion chamber 44 for needle insertion and access. The locator or “wand” is passed over the skin that is considered to be close to the graft. The wand is then used to identify and position the cannula insertion chamber 44, or one or more sites within, on, or around the graft where cannula insertion should be optimally performed. The “localization” function of the magnet-containing detector can facilitate finding the appropriate cannula insertion site while minimizing damage to the vascular access graft. The cannula insertion chamber 44 can be localized through the skin with a high degree of accuracy and precision by passing the wand across the surface of the skin in the area close to the implant. This allows the user to perform needle insertion or cannula insertion at at least one or more selected locations in the port 47 area, as determined by the presence of one or more magnetic material sites. This can be extended to applications for detecting implanted AVGs through RFID tags, i.e., concentration of specific materials that are expected to be detected by near-infrared / visible light spectroscopy or other methods known in the art.

[0030] Any suitable size of magnet can be used, but exemplary magnets include cylindrical (e.g., "button") magnets made of neodymium iron boron (NdFeB). In certain embodiments, the magnets can be coated with one or more protective layers to facilitate maximum protection and durability. Preferably, the paramagnetic material used to form the medical devices of the disclosure of the present invention includes, or is essentially composed of, iron, steel, cobalt, nickel, ceramic materials, surgical grade steel, or alloys or combinations thereof. Alternatively, the material used to form the medical devices of the disclosure of the present invention may be, for example, superparamagnetic metal oxide nanoparticles. The invention includes, or may be composed of, superparamagnetic materials containing (e.g., superparamagnetic iron oxide nanoparticles [SPIO]) [see, e.g., Ji et al. (2007)].

[0031] The number of spaced magnetic sites 70 around the rim 46 of the cannula insertion chamber 44 can be any substantial number. The vascular access graft is intended to include 2 to about 8 or 10 magnetic sites equidistant along a substantial portion of the longitudinal axis of the graft 10. Exemplary magnets for use with the access devices, grafts, and vascular access ports of the disclosure of the present invention preferably include, but are not limited to, ceramic, lanthanide, paramagnetic, ferromagnetic, or ferromagnetic materials, including, but are not limited to, aluminum, boron, cobalt, copper, iron, neodymium, nickel, samarium, titanium, or combinations thereof or alloys including, but are not limited to, commercially available permanent alloy magnets such as NdFeB, AlNi, AlCoMax, AlNiCo, and TiConAl, and are essentially composed of or substituted therefor.

[0032] In use, the user places a detector "wand" across the skin on the transplanted vascular access graft 40. A magnet on the wand detects and localizes a magnetic site on the surface of the cannula insertion chamber 44 of the transplanted vascular access graft. The needle is inserted through the skin into a port 47 of the cannula insertion chamber 44, as identified by the wand. Localization and identification of the vascular access graft 40 following transplantation are facilitated by the presence of one or more magnetic material sites 70 included together with the cannula insertion chamber 44.

[0033] In an alternative configuration, a third embodiment of the mounted applicator device is shown in Figure 5B, the whole of which is designated 80. In this embodiment, the magnet 82 is provided on the inner surface of the applicator device 80 to align with the magnet 70 on the rim 46 of the cannula insertion chamber 44. It is understood that the applicator device and subcutaneous graft may include other means for interaction in addition to or as an alternative to the magnet. Such interaction means may include a sensor on the applicator device, AVG, or both. The sensor may interact to transmit a signal for alignment, or a wand may be used as described above. The applicator device may include light for signaling. The subcutaneous cannula insertion chamber may also fluoresce under certain wavelengths, such as infrared light. Interaction may also be mechanical, such as an audible click when the application device and cannula insertion chamber are connected.

[0034] Referring here to Figure 6, multiple applicator devices 80 are shown. Each applicator device 80 has needle passages 84 formed at different locations throughout the applicator device 80. With the apparatus and method of the present invention, the user will use each applicator device 80 in sequence, one for each hemodialysis treatment. The needle passages 84 are positioned in various locations to ensure that the user inserts the needle at different locations around the cannula insertion chamber 44. As shown in Figure 7, the needle passages 84 can extend at an angle not perpendicular to the plane of the applicator device 80. In this arrangement, the needle passes through the port 47 in such a way that damage to the material of the port 47 is minimized. Figures 8A and 8B show embodiments of a dispensing container for the applicator devices. The dispensing container preferably holds the applicator devices in a sequence that provides adequate spacing of the needle passages, enabling dispensing around the cannula insertion site, which facilitates repair between needle punctures and extends graft life.

[0035] In another embodiment, the applicator device includes a sheet or sticker, as shown in Figures 9 and 10 and designated as 90 in whole. The sticker 90 is a thin, substantially rectangular element containing a planar top surface 92, a bottom surface 94, and adhesive loaded onto the bottom surface of the sticker. The sticker 90 can be removably adhered to the surface of the skin 30 to indicate the location for cannula insertion of the vascular access graft 40. The sticker 90 defines a centrally located opening 96. The opening 96, as shown in Figure 9, has a substantially elongated oval shape. The shape of the opening 96 is not particularly important, but in practice, the opening 96 should correspond to the feature of the AVG for alignment of the sticker 90 and the AVG. In the illustrated embodiment, the shape of the opening 96 in the sticker 90 corresponds to the size and shape of the cannula insertion chamber 44. The sticker 90 may include a flexible material that allows the sticker to conform to any curvature of the surface of the skin 30 and the AVG 40 beneath the skin. Thus, the curvature of the skin and any ridges beneath the skin may change without affecting the use of the sticker.

[0036] The bottom surface 94 of the sticker includes a layer of adhesive for removably adhering the sticker to the skin 30 above the vascular access graft 40. Many types of adhesives are suitable for use with the sticker 90, as long as the adhesive allows for a firm bond of the sticker 90 to the skin. The adhesive should also allow for easy removal of the sticker 90 after use. The adhesive is preferably a pressure-sensitive adhesive applied to the bottom surface 94 of the sticker 90. A wide range of such adhesives are commercially available. In one embodiment, a portion of the edge of the bottom surface 94 of the sticker 90 may lack adhesive to prevent that portion of the sticker from adhering to the skin 30. This configuration provides a place for the user to grasp the sticker 90 in order to remove it from the skin 30. The adhesive preferably leaves no residue on the skin 30 when removed.

[0037] The sticker 90 can be any size sufficient to accommodate the cannula insertion chamber 44 of the vascular access graft 40, but provides an adhesive coating area large enough to provide a strong bond between the sticker 90 and the skin 30. In one embodiment, the sticker 90 can have an outer circumference larger than the outer circumference of the cannula insertion chamber 44 so that the sticker 90 completely surrounds the chamber when placed on the vascular access graft 40. Alternatively, only the edge region of the bottom surface 94 of the sticker 90 can be coated with adhesive.

[0038] The sticker 90 may further include a protective backing that is removablely bonded to the bottom surface 94 of the sticker 90 on the adhesive layer. The removable protective backing prevents the sticker 90 from adhering to unwanted surfaces before use. The protective backing is known in the art and typically includes a variety of materials such as silicone or a compatible alternative, such as paper treated with a release agent, e.g., polyethylene and polyvinyl chloride. The removable protective backing may be the same size and shape as the sticker 90, or it may be larger. In the embodiments described above, the sticker 90 has a portion of the edge without adhesive, and the user can grasp this portion to easily remove the backing from the sticker 90.

[0039] In use, the protective backing is manually removed from the bottom surface 94 of the sticker 90 to expose the adhesive. The sticker 90 is then ready to be attached to the skin 30. The sticker 90 is positioned on the skin across the AVG 40 such that its opening 96 substantially surrounds the cannula insertion chamber 44. With the sticker 90 positioned, pressure is applied to adhere the sticker 90 to the skin 30 with the adhesive. With the sticker 90 secured to the skin 30 around the cannula insertion chamber 44 of the vascular access graft 40, the sticker 90 will allow the user to determine the location for needle insertion. Thus, the sticker 90 provides an effective method for indicating the cannula insertion location of the AVG.

[0040] In another embodiment shown in Figures 13 and 14, the sticker 90 may be designed to break apart when removed from the skin 30. For example, a portion of the sticker 90 may be made of a material having low tear propagation resistance. Combined with relatively strong adhesion of an adhesive to this portion of the sticker, the sticker will break apart when removed from the surface. More specifically, by removing the sticker 90 from the skin 30, a portion of the material containing the sticker 90 will remain in the skin. The portion of the sticker left in the skin is a mark, such as an inspection mark 98, which is easily visible to the human eye and indicates a point for needle insertion of the AVG 40 that will be underneath. The next sticker 90 leaves an inspection mark 98 on the skin 30 at the next site for cannula insertion. In another embodiment shown in Figure 14, a boundary mark may remain in the skin when the sticker is removed, thereby providing an indication of the location of the cannula insertion chamber. A preferred sticker according to this embodiment is shown in U.S. Patent No. 4,268,983, the contents of which are incorporated by reference, which describes an adhesive label comprising a support sheet and a fragile, easily tearable film adhered to the support sheet. When the label according to the '983 patent is removed from the article to which it was attached, a portion of the fragile film containing the label is torn and remains adhered to the substrate. U.S. Patent No. 5,358,281, the contents of which are incorporated by reference, describes an adhesive label that leaves a component of the label on a surface including a visible mark when removed. It is understood that the mark left on the surface may be alphanumeric characters spelling out a word. U.S. Patent No. 4,121,003, the contents of which are incorporated by reference, also describes the transfer of alphanumeric characters upon removal of a label, the letters including a low-bonding material such that the label breaks within itself when the adhesive label is separated from the surface, and it remains partially on the surface to which it was attached.

[0041] In another embodiment, as shown in Figure 12, the sticker 90 is a single unit without an opening. A portion of the sticker 90 configured to indicate the cannula insertion chamber 44 includes a section for identifying a site available for cannula insertion. One section 102 of the sticker 90 is removable. In use, the sticker 90 is attached to the skin 30 over AVG 40. The section 102 of the sticker over the cannula insertion site is peeled off from the surface of the skin 30. The exposed skin 30 is then used as a site for needle insertion. U.S. Patent No. 5,633,058, whose contents are thus incorporated by reference, describes a transparent printed mark that is loosely attached to a backing film to which a sticker has an all-over colored layer that adheres well to the backing film and the printed mark. The colored layer is coated with a self-adhesive composition.

[0042] Embodiments for use in combination with an applicator device for positioning an applicator device for positioning a cannula insertion point of an implanted AVG are shown in Figures 15A and 15B, the whole being designated 110. The combination includes a pair of circular flexible straps 112 for securing the applicator device 116 to a part of the user's body, which is the arm, as shown in Figure 16. The applicator device 116 has grooves 114 at each end to receive the straps 112. In use, the applicator device 116 is positioned over the cannula insertion chamber 44 as described above. The straps 112 then secure the applicator device in place for subsequent nucleus insertion. One advantage of this arrangement is that following hemodialysis and needle removal, the straps 112 press the applicator device 116 against the arm, providing pressure to help stop bleeding.

[0043] Another embodiment of the apparatus and method for guiding cannula insertion into an arteriovenous graft using strap 112 is shown in Figure 17. In this embodiment, strap 112 provides means for positioning the cannula insertion chamber 44 for subsequent nucleus insertion. Each of the straps 112 has two circumferentially spaced notches 118 on its inner surface 112. The notches 118 are configured to receive the ends of a pair of cannula insertion chambers 44 when placed on the patient's AVG 40. Together, the straps 112 indicate the ends of the cannula insertion chambers 44 to the user to assist the user in identifying the location for cannula insertion. The straps 112 function to lock the cannula insertion chambers 44 and prevent any movement of the device. In this way, the device can be secured to the cannula insertion chambers on either end.

[0044] Referring here to Figure 18, yet another embodiment of the applicator device for determining the location for cannula insertion into the vascular access graft 40 is shown and is designated 130. In this embodiment, the applicator device 130 is a sleeve 132 for sliding over the arm. The sleeve 132 is made of a flexible elastic fabric so that it stays tightly on the arm when worn. The sleeve 132 defines a pair of circumferentially spaced openings 134 having a substantially elongated oval shape. The shape of the openings 134 is not so important, but in fact, the openings 134 must correspond to the shape of the AVG or a feature of the AVG for opening and AVG alignment. In the illustrated embodiment, the shape of the openings 134 of the sleeve 132 corresponds to the size and shape of the cannula insertion chamber 44.

[0045] In use, the sleeve 132 is positioned on the arm with an opening above the cannula insertion chamber 44. The user can then insert the vascular access graft 40 via cannula. In yet another embodiment, each of the openings 134 within the sleeve 132 forms a pocket 136 having a layer of material adjacent to the skin 30 (Figure 19). The pocket 136 is configured to receive an applicator device for use in positioning and cannula insertion of the AVG (Figure 20).

[0046] Apparatus and methods for cannula insertion into vascular access grafts, as described herein, offer numerous advantages, including providing a reliable means to enable the user to perform hemodialysis while always and accurately accessing the graft site. Using an external device to identify and localize the location of the implanted device reduces inaccurate cannula insertion and facilitates increased patency of vascular access grafts after surgical implantation into the body. Fewer incorrect needle and cannula insertion errors reduce the chance of damaging, destroying, or displacing the graft due to inaccurate cannula insertion or improper or repeated needle puncture attempts to "hit" the correct insertion site on the subcutaneous graft. Cumulative damage resulting from repeated needle punctures weakens the graft wall and creates conditions for pseudoaneurysm formation. AVG sustains approximately 300 needle punctures in one year. Apparatus and methods, as described herein, that provide needle rotation to evenly distribute needle damage across the entire length of the graft help minimize or delay pseudoaneurysm formation.

[0047] The apparatus of the present invention tracks the location of the cannula insertion site and thus ensures that proper needle rotation is performed. A system or sequence designed to facilitate needle rotation facilitates proper needle rotation through the cannula insertion site region by maintaining compliance with an facilitated cannula insertion sequence.

[0048] The present invention also enhances the function of patients or medical personnel and ensures proper and accurate identification and placement of transplanted vascular access grafts. Vascular access grafts can be visualized by conventional medical imaging methods, including, for example, X-ray, magnetic resonance imaging, and / or computed tomography (CT).

[0049] Although the present invention has been illustrated and described in considerable detail with respect to only a few exemplary embodiments, it should be understood by those skilled in the art that the invention is not intended to be limited to these embodiments, as various modifications, omissions, and additions can be made to the embodiments disclosed in particular in light of the above-mentioned teachings without departing significantly from the new teachings and advantages of the invention. For example, the invention is suitable for use in several vascular access devices and applications. Accordingly, the inventors intend to affix a sticker that all such modifications, omissions, additions, and equivalents may be included in the spirit and scope of the invention as defined by the claims. In the claims, the means plus function clause is intended to affix a sticker as performing the functions listed in the structures described herein and as structural equivalents as well as equivalent structures. That is, nails and screws may be equivalent structures, although nails may not be structural equivalents in that nails use a cylindrical surface to fasten wooden parts together, while screws use a helical surface in an environment in which wooden parts are fastened. [Explanation of Symbols]

[0050] 40 Vascular access grafts 44 Cannula insertion chamber 46 Perimeter rim 50 Applicator Devices 54 Side walls or legs (Aspect) (Aspect 1) An arteriovenous dialysis graft comprising a flexible conduit defining a longitudinal flow path, the flexible conduit having a first terminal portion configured to connect to the subject's artery and a second terminal portion configured to connect to the subject's vein, thereby allowing blood to flow through the longitudinal flow path of the conduit from the first terminal portion to the second terminal portion, and a cannula insertion chamber defining a cannula insertion port, the conduit extending through the cannula insertion chamber to receive a dialysis needle inserted through the cannula insertion port, an apparatus for guiding cannula insertion using a dialysis needle of an arteriovenous dialysis access graft subcutaneously implanted in the body of a subject, An elongated body member having a longitudinal axis and an inner surface, wherein the body member includes a base portion terminating within the longitudinal edge, and the distance between the longitudinal edges of the base portion is substantially equal to the lateral dimension of the cannula insertion chamber, A leg extending from the longitudinal edge of the base portion and terminating within the longitudinal edge, wherein the base portion and the leg define an open longitudinal channel for receiving the cannula insertion chamber, Includes, The main body member is fixed adjacent to the subcutaneous cannula insertion chamber such that the legs operatively engage with the cannula insertion chamber in order to align the inner surface of the base portion with the cannula insertion port in order to guide the needle insertion site into the cannula insertion chamber through the main body member. A device for induction characterized by the following features. (Aspect 2) The main body member has a first end and a second end, The main body member extends from the first end to the second end of the cannula insertion chamber. An induction device according to embodiment 1, characterized by the following: (Aspect 3) The induction device according to embodiment 1, characterized in that the main body member has at least one passage that opens into the inner surface of the main body member for passing a needle through. (Aspect 4) The induction device according to embodiment 1, characterized in that at least a portion of the cannula insertion chamber and the main body member contains a substantially magnetic or paramagnetic material. (Appendix 5) A device for guiding cannula insertion using a dialysis needle of an arteriovenous dialysis access graft subcutaneously implanted in the body of a subject, wherein the arteriovenous dialysis graft includes a flexible conduit defining a longitudinal flow path, the flexible conduit having a first terminal portion configured to connect to the subject's artery and a second terminal portion configured to connect to the subject's vein, so that blood flows through the longitudinal flow path of the conduit from the first terminal portion to the second terminal portion, and a cannula insertion chamber defining a cannula insertion port between the first and second terminal portions, the conduit extending through the cannula insertion chamber to receive a dialysis needle inserted through the cannula insertion port, An elongated tubular sleeve having a longitudinal axis, wherein the elongated tubular sleeve defines an opening having longitudinal and transverse dimensions that are substantially equal to the longitudinal and transverse dimensions of the cannula insertion chamber, Includes, The sleeve is configured to receive the subject's body adjacent to the subcutaneous cannula insertion chamber of the access graft, such that the opening surrounds the cannula insertion chamber to guide the location of needle insertion into the cannula insertion port. A device for induction characterized by the following features. (Aspect 6) The induction device according to embodiment 5, characterized in that the material of the sleeve is selected from film, paper, woven fabric, or nonwoven fabric. (Aspect 7) A device for guiding cannula insertion using a dialysis needle of an arteriovenous dialysis access graft subcutaneously implanted in the body of a subject, wherein the arteriovenous dialysis graft includes a flexible conduit defining a longitudinal flow path, the flexible conduit having a first terminal portion configured to connect to the subject's artery and a second terminal portion configured to connect to the subject's vein, so that blood flows through the longitudinal flow path of the conduit from the first terminal portion to the second terminal portion, and a cannula insertion chamber defining a cannula insertion port between the first and second terminal portions, the conduit extending through the cannula insertion chamber to receive a dialysis needle inserted through the cannula insertion port, An elongated body member having a longitudinal axis and an inner surface, wherein the body member includes a base portion terminating within the longitudinal edge, and the distance between the longitudinal edges of the base portion is substantially equal to the lateral dimension of the cannula insertion chamber, An elongated tubular sleeve having a longitudinal axis, wherein the elongated tubular sleeve has a pocket having longitudinal and transverse dimensions configured to receive the main body member, Includes, The main body member is received into the pocket of the sleeve so as to be fixed adjacent to the subcutaneous cannula insertion chamber, such that the inner surface of the base portion is aligned with the cannula insertion port to guide the needle insertion location. A device for induction characterized by the following features. (Pattern 8) It's a kit, At least one dialysis needle for accessing an arteriovenous dialysis access graft subcutaneously implanted in the body of a subject, wherein the arteriovenous dialysis graft includes a flexible conduit defining a longitudinal flow path, the flexible conduit having a first terminal portion configured to connect to an artery of the subject and a second terminal portion configured to connect to a vein of the subject, thereby allowing blood to flow through the longitudinal flow path of the conduit from the first terminal portion to the second terminal portion, the cannula insertion chamber defining a cannula insertion port, and the conduit extending through the cannula insertion chamber to receive the needle inserted through the cannula insertion port, Dispensing container and A plurality of elongated body members, each having a longitudinal axis and an inner surface, and including a base portion that terminates within the longitudinal edge, wherein the distance between the longitudinal edges of the base portion is substantially equal to the lateral dimension of the cannula insertion chamber, Includes, The main body member is fixed adjacent to the subcutaneous cannula insertion chamber such that its legs operatively engage with the cannula insertion chamber in order to align the inner surface of the base portion with the cannula insertion port in order to guide the needle insertion site. Each body member has at least one passage that opens into the inner surface of the body member for the needle to pass through, and the needle passage of the body member is located in a different position from the needle passage of any other body member. A kit characterized by the following features.

Claims

1. A kit for inducing cannula insertion using a dialysis needle, Multiple applicator devices configured to align with the cannula insertion chamber of an arteriovenous dialysis access graft subcutaneously implanted in the subject's body, A distribution cartridge including a cavity for holding the plurality of applicator devices, Includes, The arteriovenous dialysis access graft has a flexible conduit that defines a longitudinal flow path and a first terminal portion configured to connect to the subject's artery and a second terminal portion configured to connect to the subject's vein, thereby allowing blood to flow through the longitudinal flow path of the conduit from the first terminal portion to the second terminal portion, the cannula insertion chamber defines a cannula insertion port between the first terminal portion and the second terminal portion at a first position, the first applicator device includes a first needle passage defined therethrough, and the second applicator device includes a second needle passage defined therethrough at a second position, and for each applicator device, the first position differs from the second position. The distribution cartridge kit further includes a tray that can operate to provide access to a single applicator device.

2. The kit according to claim 1, wherein the distribution cartridge is configured to provide the next applicator device when the single applicator device is removed from the tray.

3. The kit according to claim 2, wherein the dispensing cartridge is configured to provide access to a subsequent applicator device, the subsequent applicator device having a needle passage located at a different position from the single applicator device.

4. The kit according to claim 3, wherein each of the plurality of applicator devices is provided sequentially in the tray, and each of the applicator devices has a needle passage located at a different position relative to the previous applicator device and the next applicator device.

5. The kit according to claim 1, wherein each of the needle passages extends at an angle to each of the surfaces of the applicator device.

6. The kit according to claim 1, further comprising a plurality of elongated body members, each having a longitudinal axis and an inner surface, the elongated body member including a base portion having longitudinal edges, the distance between the longitudinal edges of the base portion being substantially equal to the lateral dimension of the cannula insertion chamber.

7. The kit according to claim 6, wherein the elongated main body member is fixed to the cannula insertion chamber by a fitting between the legs and the cannula insertion chamber or by magnetic force between the legs and the cannula insertion chamber, with skin sandwiched between the elongated main body member and the cannula insertion chamber, such that the legs extending from the longitudinal edge engage with the cannula insertion chamber to align the inner surface of the base portion with the cannula insertion port in order to guide the insertion site of the dialysis needle.

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