Patent Application
20050137614
1. Field of the Invention
This invention relates generally to connectors used to join fluid conduits within the body. These fluid conduits may include AV grafts, implantable catheters, left ventricular assist devices, as well as native tissue vessels.
2. Description of the Related Art
In the United States, approximately 300,000 people have end-stage renal disease requiring chronic hemodialysis. Although many materials that have been used to create prosthetic arterio-venous (AV) grafts have also been tried for dialysis access, expanded polytetrafluoroethylene (ePTFE) has become the material of choice. The reasons for this include its ease of needle puncture and particularly low complication rates (pseudo-aneurysm, infection, and thrombosis). However, patency rates of ePTFE access grafts are still not satisfactory and overall graft failure rates remains high. Sixty percent of these grafts fail yearly, usually due to stenosis at the venous end. (See Besarab, A & Samararpungavan D., “Measuring the Adequacy of Hemodialysis Access”. Curr Opin Nephrol Hypertens 5(6) 527-531, 1996, Raju, S. “PTFE Grafts for Hemodialysis Access”. Ann Surg 206(5), 666-673, November. 1987, Koo Seen Lin, L C & Bumapp, L. “Contemporary Vascular Access Surgery for Chronic Hemodialysis”. J R Coll Surg 41, 164-169, 1996, and Kumpe, D A & Cohen, M A H “Angioplasty/Thrombolytic Treatment of Failing and Failed Hemodialysis Access Sites: Comparison with Surgical Treatment”. Prog Cardiovasc Dis 34(4), 263-278, 1992, all herein incorporated by reference in their entirety.) These failure rates are increased in higher-risk patients, such as diabetics. These access failures result in disruption of routine dialysis schedules and create hospital costs of over $2 billion per year. (See Sharafuddin, M J A, Kadir, S., et al. “Percutaneous Balloon-assisted aspiration thrombectomy of clotted Hemodialysis access Grafts”. J Vasc Interv Radiol 7(2) 177-183, 1996, herein incorporated by reference in its entirety).
In one embodiment, a biocompatible connector for joining body fluid conduits is provided. The connector comprises an elongate body, the elongate body comprising a first end having a first outer diameter and adapted to receive a first body fluid conduit, a second end adapted to receive a second body fluid conduit, and a lumen between the first end and the second end of the elongate body, the lumen comprising an first opening and an second opening, and a length, a first edge about the first opening, and a second edge about the second opening, wherein the first opening diameter is at least about 90% of the first outer diameter. In further embodiments, the first opening diameter may at least about 95% of the first outer diameter, sometimes at least about 98% of the first outer diameter. The first opening may be an inflow opening or an outflow opening. The second opening may be an inflow opening or an outflow opening. The first edge may comprise a smoothed surface. The elongate body may further comprise a first transition zone within the lumen, the first transition zone comprising a first inner diameter and a second inner diameter located generally between the first opening and the second opening, wherein the first inner diameter is greater than the second inner diameter. The elongate body may also comprise a second transition zone within the lumen, the second transition zone comprising a third inner diameter and a fourth inner diameter located generally between the second inner diameter and the second opening. In one embodiment, the third inner diameter is greater than the fourth inner diameter. In another embodiment, the third inner diameter is less than the fourth inner diameter. The change in diameter from the first inner diameter to the second inner diameter may be linear. The first inner diameter may be located about the first opening. The second inner diameter may be located at a distance of at least about 20% of the lumen length from the first inner diameter, sometimes at least about 50% of the lumen length from the first inner diameter, and occasionally no greater than about 90% of the lumen length from the first inner diameter. The lumen wall in the first transition zone may form an angle of less than about 20 degrees with respect to the longitudinal axis of the lumen, sometimes less than about 10 degrees, and preferably less than about 5 degrees. Occasionally, the lumen wall in the first transition zone forms an angle of less than about 3 degrees with respect to the longitudinal axis of the lumen. The elongate body may further comprise a middle segment between the first end and the second end. The middle segment may comprise a central flange. The middle segment may also comprise a first indentation region. The elongate body may comprise a material selected from the group comprising titanium or a titanium alloy, nickel or a nickel alloy, MP35N, stainless steel, polysuflone, PEEK, nylon, polypropylene or polyethylene or any flexible or chip-resistant polymer. The biocompatible connector may further comprise a first securing device capable of exerting a radially inward force against the first conduit at the first indentation region. The first securing device may comprise a suture, a twisted wire, a tension clip, a crimp ring, a clamshell assembly, a collet assembly, or a compression sleeve. The middle segment may also comprise a mechanical interlock interface capable of joining and separating the first end and the second end of the elongate body. The middle segment may also comprise a lumen access interface. The lumen access interface may be adapted for leak-resistant needle puncture access. The lumen access interface may be subcutaneous or transcutaneous. The biocompatible connector may further comprise a connector sleeve with a first end and a second end, and a sleeve lumen therebetween, the tubular sleeve having a first expanded sleeve configuration and a second reduced sleeve configuration, the second reduce sleeve configuration capable of exerting a radially inward bias. The compression sleeve may comprise a material selected from the group comprising silicone, polyurethane, spring metal, a flexible polymer and a chip-resistant polymer. The biocompatible connector may further comprise a strain relief assembly positioned about the first end of the elongate body. The strain relief assembly may comprise a wire or polymer coil. The elongate body may have a first wall thickness measured in the lumen at a distance of no greater than about 1 mm from the first opening, sometimes at a distance of no greater than about 0.5 mm from the first opening and occasionally at the inflection point between the first edge and the lumen. The first wall thickness may be generally within the range of about 0.030 mm to about 0.250 mm, about 0.075 mm to about 0.200 mm or about 0.100 mm to about 0.180 mm.
In another embodiment, a system for treating renal disease is provided. The system comprises a graft having a first end configured for anastomosis to a blood vessel, a second end adapted to connect to a catheter, and a lumen between the first end and the second end, and a catheter having a first end configured for insertion into a vein, a second end adapted to connect to a graft, and a lumen between the first end and the second end, wherein the second end of the catheter has a wall thickness at a measuring point defined at the inflection point between the first edge and the lumen, and the wall thickness is no greater than about 0.250 mm. The wall thickness may be within the range of about 0.030 mm to about 0.250 mm, about 0.075 mm to about 0.200 mm, or about 0.100 mm to about 0.180 mm.
In another embodiment of the invention, a method for implanting a body fluid conduit is provided, comprising the steps of providing a first body fluid conduit, a second body fluid conduit and a connector having a first end, second end, a lumen between the first end and second end, and a first wall thickness at the first end, wherein the first wall thickness is no greater than about 0.250 mm, attaching the first body fluid conduit to a blood vessel, inserting the second body fluid conduit into a blood vessel, connecting the first body fluid conduit to the first end of the connector, and connecting the second body fluid conduit to the second end of the connector. In some embodiments, the step of connecting the first body fluid conduit to the second end of the connector is performed before the inserting step. In some embodiments, the step of connecting the second body fluid conduit to the second end of the connector is performed before the inserting step. In some embodiments, the first end and/or second end of the connector may be preattached to the first body fluid conduit and/or second body fluid conduit, respectively.
In another embodiment, a hemodialysis and vascular access system is provided, comprising an indwelling tubular conduit having a first section provided from a material which is biocompatible with and adapted for attachment to an artery and a second section adapted to be inserted within a vein at an insertion site, said second section having an outside diameter which is less than an inner diameter of the vein at the insertion site and having at least one opening in an end thereof which is distant from the insertion site such that, in operation, blood flows from the artery through the conduit and is returned to the vein through the at least one opening and blood also flows through the vein uninterrupted around the outside of the second section, and a connector connecting the first and the second sections, the connector having a tubular body with a central lumen extending therethrough, wherein the central lumen has a first inside diameter adjacent a transition to the first section and a second inside diameter adjacent a transition to the second section, and a nonturbulent transition in the lumen between the first diameter and the second diameter. The first section may comprise ePTFE, polyurethane, silicone or Dacron®. The first section may have an inside diameter within the range of from about 5.5 mm to about 6.5 mm, and sometimes about 5 mm to about 7 mm. The second section may comprise a silastic material or silicone. A downstream end of the second section may be provided with a bevel. The hemodialysis and vascular access system may additionally comprise an access segment for receiving a needle to allow access to blood flowing through the conduit. The first inside diameter is at least about 95% of a corresponding outside diameter, or even at least about 98% of a corresponding outside diameter. In some embodiments, at least one edge about an opening of the central lumen comprises a smoothed surface. The nonturbulent transition in the lumen may be linear. The second inside diameter may be located at a distance of at least about 20% of the lumen length from the first inside diameter, sometimes at least about 50% of the lumen length from the first inside diameter and occasionally no greater than about 90% of the lumen length from the first inside diameter. The lumen wall about the nonturbulent transition may be angled less than about 20 degrees with respect to the longitudinal axis of the lumen, preferably less than about 10 degrees or 5 degrees, and occasionally less than about 3 degrees with respect to the longitudinal axis of the lumen. The connector may comprise a middle segment between the first section and the second section. The middle segment may comprise a central flange. The middle segment may also comprise a first indentation region. The connector may comprise a material selected from the group comprising titanium or a titanium alloy, nickel or a nickel alloy, MP35N, stainless steel, polysuflone, PEEK, nylon, polypropylene or polyethylene or any flexible or chip-resistant polymer. The hemodialysis and vascular access system may further comprise a first securing device capable of exerting a radially inward force against the first section at the first indentation region. The first securing device may comprise a suture, suture, a twisted wire, a tension clip, a crimp ring, a clamshell or collet assembly, or a compression sleeve. The middle segment may also comprise a mechanical interlock interface capable of joining and separating the first section and the second section of the connector. The middle segment comprises a central lumen access interface. The central lumen access interface may comprise a leak-resistant needle puncture access zone. The central lumen access interface may be subcutaneous or transcutaneous. The hemodialysis and vascular access system may further comprise a connector sleeve with a first end and a second end, and a sleeve lumen therebetween, the tubular sleeve having a first expanded sleeve configuration and a second reduced sleeve configuration, the second reduce sleeve configuration capable of exerting a radially inward bias. The compression sleeve may comprise a material selected from the group comprising silicone, polyurethane, a flexible polymer and a chip-resistant polymer. The hemodialysis and vascular access system may further comprise a strain relief assembly positioned about the first section adjacent to the connector. The strain relief assembly may comprise a wire or polymer coil. The connector may have a first wall thickness measured in the central lumen at a distance of no greater than about 1 mm from the opening of the central lumen adjacent to the first section, and a distance of no greater than about 0.5 mm from the opening of the central lumen adjacent to the first section. The connector may also have a first wall thickness measured at the inflection point between the wall of the central lumen and the opening of the central lumen adjacent to the first section. The first wall thickness is generally within the range of about 0.030 mm to about 0.250 mm, sometimes generally within the range of about 0.075 mm to about 0.200 mm, and occasionally generally within the range of about 0.100 mm to about 0.180 mm.
In one embodiment, a vascular access system is provided, comprising an indwelling catheter having a first end with a first outer diameter and adapted to join a body fluid conduit, a second end adapted to be inserted within a vein at in insertion site, the second end having an outside diameter which is less than an inner diameter of the vein at the insertion site and having at least one opening which is distant from the insertion site such that, in operation, body fluid from the body fluid conduit is capable of flowing through the catheter and returned to the vein through at least one opening and blood also flows through the vein uninterrupted around the outside of the second end, and a lumen extending therethrough, wherein the lumen opening about the first end has a diameter at least about 90% of the first outer diameter.
In another embodiment, the invention comprises a hemodialysis and vascular access system, comprising a first body fluid conduit, a second body fluid conduit, and a needle access site, the needle access site comprising a first end having a first outer diameter and adapted to join the first body fluid conduit, a second end adapted to join the second body fluid conduit, and a lumen between the first end and the second end of the needle access site, the lumen comprising an inflow opening and an outflow opening, and a length, a first edge about the inflow opening, and a second edge about the outflow opening, wherein the inflow opening is at least about 90% of the first outer diameter.
Further features and advantages of the present invention will become apparent to those of skill in the art in view of the disclosure herein, when considered together with the attached drawings and claims.
The structure and method of using the invention will be better understood with the following detailed description of embodiments of the invention, along with the accompanying illustrations, in which:
Kanterman hypothesizes that the primary causes of the localized stenosis are due to intimal hyperplasia, compliance mismatch between the graft and the native vein anastomosis and turbulent flow (Kanterman R. Y. et al “Dialysis access grafts: Anatomic location of venous stenosis and results of angioplasty.” Radiology 195: 135-139, 1995, herein incorporated by reference in its entirety). In our work, it was hypothesized that these causes could be circumvented by eliminating the venous anastomosis and instead, using a catheter to discharge the blood directly into the venous system. The device developed by GRAFTcath, Inc. to eliminate the venous anastomosis in the AV shunt has a catheter at the venous end and a synthetic graft anastomosed to the artery in the standard fashion.
Although these devices may be may be constructed as a single-piece, integrated device, a multi-piece device comprising separate components that are later joined together may also be designed. A multi-component device may have several advantages. First, a multi-piece device allows switch-out of one or more components of the device. This allows the tailoring of various device characteristics to the particular anatomy and/or disease state, for instance, by using components of different dimensions. This also reduces the cost of treating patients in several ways. It reduces the amount of inventory of a given device by stocking an inventory range of components, rather than an inventory range of complete devices. Also, if an incorrect device is initially selected for use in a patient, only the incorrect component is discarded, rather than the entire device. Second, separate multiple components of a device may be easier to manufacture compared to an integrated form of the device. Third, it may be easier for a physician to implant separate components of a device and then join them together rather than implanting an integrated device. Fourth, it allows the components to be trimmable as needed to accommodate various patient anatomies. An integrated device may be excessively bulky and can slow the implantation procedure, thereby increasing operating room time and costs as well as increasing the risk of physician error.
The interfaces where separate components are joined or attached, however, are potential sources of turbulent flow along the blood flow path of the device. Sharp indentations or protrusions of the lumen will cause alterations in flow at the interface that may result in hemolysis and clot formation. Such an interface may create an increased risk of creep or separation of joined components over time that can worsen the flow characteristics at the interfaces or even result in loss of flow, respectively. Thus, the connector system used to attach the various components may benefit from one or more design features that maintain smooth flow between components through the interface and also resist creep or separation of the joined components. Such a connector system may be used with AV grafts, peripherally inserted central catheters (PICC), implantable infusion catheters with and without fluid reservoirs, implantable infusion pumps, left ventricular assist devices, and any other device where providing laminar flow between two body fluid conduits may be beneficial. For example, such a connector may be used to join an arterial graft and a venous catheter as described by Squitieri in U.S. Pat. No. 6,102,884 and U.S. Pat. No. 6,582,409, and by Porter in U.S. Provisional Application No. 60/509,428, herein incorporated by reference in their entirety. In addition to joining tubular conduits, the connector may also be used to join conduit or reservoir containing devices such as needle access ports as described by Porter in U.S. Provisional Application No. 60/605,681, herein incorporated by reference in their entirety. The connectors may also be integrated with such conduit or reservoir containing devices.
In one embodiment of the invention, a connection system for attaching a catheter to a graft in an AV hemodialysis shunt is provided. The connection system may comprise a biocompatible and/or hemocompatible material. The connection system may also provide for the attaching of a graft and a catheter having different internal and/or outer diameters. In some embodiments of the invention, the connection system provides a lumen with a smooth fluid path from one end of the connection system to the other. The smooth fluid path may reduce the risk of clot formation and hemolysis of red blood cells. The connector system may also have a securing system for resisting disconnection of the joined components. An anti-kink system may also be provided to resist occlusion along portions of the catheter and/or graft. An anti-kink system may be advantageous for an AV graft comprising PTFE or a catheter which is made from silicone or polyurethane that may be prone to bending and/or twisting. It may also be advantageous to preconnect one element to the connector before the start of surgery with then makes the procedure easier to perform in the operating room and it may also reduce the chance of error.
Where the connector is used to join conduits having generally similar inside diameters, the lumen diameter of the connector may be generally constant from the proximal portion of the first end to the distal portion of the second end. More typically, however, the conduits have different inner diameters, where the first fluid conduit has a greater diameter than the second fluid conduit. Referring back to
In other embodiments, the first fluid conduit 12 may have a smaller diameter than the second fluid conduit 14 and the connector 2 may be configured so that the most proximal portion 16 of the lumen 10 generally has a smaller diameter and the most distal portion 18 of lumen 10 generally has a larger diameter.
In one embodiment, the transition zone 20 of the connector 2 where the lumen diameter transitions from the larger diameter D′ to the smaller diameter D″ is preferably located at the most proximal portion 16 of the connector and extends distally to at least to the distal portion 22 of the first end 4. The transition zone 20 may also begin at the distal portion 22 of the first end 4, the middle portion 6, or the proximal portion 24 of the second end 8 of the connector 2, and terminate at the middle portion 6, the proximal portion 24 of the second end 8 or the distal portion 18 of the second end 8 of the connector 2, depending on the length of the transition zone 20 desired.
A connector may also have more than one transition zone. Referring to
As depicted in
To further reduce flow turbulence or non-laminar flow and prevent damage to the surface of the inner surface of the conduits at one or more edges 26, 28 of the connector 2, the first end 4 and/or second end 8 of the connector 2 may be advantageously rounded or smoothed. Rounded edges may also decrease the risk of trauma to the conduits 12, 14 during insertion of the connector 2 into the conduits 12, 14. As shown in
The outer diameter od′ of the first end 4 of the connector 2 may be generally constant or it may taper from distal to proximal. In some circumstances, a first end 4 with a generally constant outer diameter may be preferable because the generally constant outer diameter reduces the deformation of the first conduit 12 at the junction of the connector edge 26 and the first conduit 12. The reduced deformation may preserve the structural integrity of the first conduit 12 when joined to the connector 2. It may also reduce the inward deformation that may occur at the junction of the connector edge 26 and the first conduit wall, which can provide a smoother fluid path transition from first conduit 12 to the connector 2. A tapered end, however, may facilitate insertion of the connector 2 into the lumen of the first conduit 12 while providing resistance to separation between the conduit 12 and connector 2.
The outer diameter od″ of the second end 8 of the connector 2 may also be generally constant or have a taper to facilitate insertion into the second conduit 14. In some embodiments, a tapered outer diameter of the connector 2 may be preferred because the effect on flow dynamics, if any, from the lumen 10 of the connector 2 to the larger lumen of the second conduit 14 may not be significant. A taper at the second end 8 of the connector 2 may facilitate insertion of the second conduit 14 with little or no increase in flow turbulence or non-laminar flow. The configuration of one or both connector ends 4, 8 may be the same or different, and may be selected by one skilled in the art depending upon the flow direction, desired flow characteristics, conduit materials and characteristics, and other factors.
The middle portion 6 of the connector 2 has a proximal end 34 adjacent to the first end 4 of the connector 2, a distal end 36 adjacent to the second end 8 of the connector 2, and contains a segment of lumen 10. In one embodiment of the invention, the middle portion 6 has a radially outwardly extending annular flange 38 along at least one portion of its outer diameter that limits the insertion of the first end 4 and second end 8 into their respective conduits 12, 14. The insertion limit may prevent overinsertion of the connector 2 into the conduit, resulting in possible loss of the connector and/or damage to the conduit.
In some embodiments, the middle portion 6 of the connector 2 comprises one or more regions with indentations or a reduced outer diameter 40, 42 with respect to the adjacent outer diameters of the first end 4 and/or second end 8 of the connector 2. Preferably, the connector 2 has a first reduced outer diameter region 40 such as an annular recess adjacent to the first end 4 of the connector 2 and a second reduced outer diameter region 42 such as an annular recess adjacent to the second end 8 of the connector 2, but this is not required. The two regions 40, 42 need not be configured similarly. The regions 40, 42 on the middle portion 6 of the connector 2 allow conduits 12, 14 inserted over the first end 4 and/or second end 8 of the connector 2 to be secured to the connector 2 by placing a radially inward force on the conduits 12, 14 that can partially deform the conduits 12, 14 radially inward and increase resistance to separation from the connector 2 through a friction fit and/or mechanical interfit by abutting against the larger diameter of the first end 4 and/or second end 8 of the connector 2. The indentation or reduced outer diameter regions 40, 42 may involve only a portion of the circumference of the connector 2, but typically will involve the entire circumference of the connector 2. Structures for securing the conduits 12, 14 onto the connector 2 are described in further detail below.
In one embodiment, the connector 2 has a length of about 10 mm to about 50 mm, and preferably about 15 mm to about 30 mm and more preferably about 20 mm to about 25 mm. The connector may comprise any of a variety of biocompatible materials, such as titanium or a titanium alloy, nickel or a nickel alloy, MP35N, stainless steel, polysuflone, PEEK, nylon, polypropylene or polyethylene or any flexible or chip-resistant polymer. All or a portion of the outer and/or inner surface of a metallic connector may be passivated or anodized. All or a portion of the outer and/or inner surface of the connector may be coated or insert molded with silicone or other hemocompatible material to provide a lubricious characteristic or to augment other properties of the connector, such as corrosiveness and/or clot formation. The connector may further comprise a drug eluting surface capable of eluting a therapeutic agent that can reduce the risk of infection, clot formation or affect tissue growth about the connector 2.
In one embodiment, the connector sleeve 44 comprises silicone, polyurethane or other polymer in its unexpanded state, has an average inner diameter less than that of the largest outer diameter and/or average outer diameter of the connector 2. The connector sleeve 44 is radially expanded as it is placed over the connector 2 and joined conduits 12, 14, thereby imparting a radially inward compression force.
In another embodiment, the connector sleeve 44 comprises a polymer that may be UV or heat shrunk onto the connector 2. UV and heat shrink polymers include but are not limited to PTFE, FEP, PFA, PET, and PTFE/FEP. In still other embodiments, the connector sleeve 44 may be adhered to the connector 2 and/or conduits 12, 14 with cyanoacrylate, a curable glue, or other adhesive. In still another embodiment, the connector sleeve 44 comprises a tubular lattice structure similar to a stent that is crimped onto the connector system. The stent may also comprise a shape memory material such as Nitinol that is capable of expanding with increased temperature and reducing in diameter with cooling to apply a radially inward force to the sleeve 44 or connector 2.
Securing structures or devices may be applied to the conduits to secure the conduits to the connector. These securing devices 46 may be applied directly to the outer surface of the conduits 12, 14, as shown in
The radially inwardly facing surface of the connector sleeve 44 may also comprise at least one inner ring, indentation or other structure that is complementary to a corresponding structure on the outside surface of the connector and/or conduits that can facilitate positioning and/or securing of the sleeve 44 onto the connector 2. For example, the sleeve 44 may have a radially inwardly extending ring or thread that is complementary to a circumferential indentation area 40, 42 on the connector 2. The inner ring of the sleeve 44 may be segmented and complementary to a series of circumferential indentations on the connector to facilitate rotational alignment of the sleeve and connector in addition to longitudinal alignment.
In some embodiments of the invention, the interior surface of the connector sleeve 44 may have a lubricious coating to facilitate sliding of the sleeve 44 over the connector 2 and/or conduits 12, 14. The sleeve 44 may also comprise a porous material to facilitate tissue ingrowth and fixation of the connector system position within the body. Fixation of the connector system position may be advantageous when attempting puncture or obtain access to the joined conduits/grafts by preventing rolling or lateral displacement of the conduits caused by a puncturing force.
As shown in
Any of a variety of securing devices may be used to secure the conduits and/or connector sleeve 44 to the connector 2.
In one embodiment, shown in
In one embodiment of the invention, the connector system comprises a catheter 80 integrated with a connector-like end 82.
In another embodiment of the invention, an AV shunt comprising a first body fluid segment, a second body fluid segment and a connector is provided. The first body fluid segment is configured for attachment to an artery and the second body fluid segment is adapted for insertion into a vein. The first body fluid segment may comprise a synthetic vascular graft. The synthetic vascular graft comprises a porous structure made from materials such as PTFE, polyurethane or silicone. In some embodiments of the invention, access to the AV shunt may be obtained by direct needle puncture of the vascular graft. The synthetic vascular graft may also comprise a biological material derived from humans or animals. Some embodiments of the vascular graft may be using needles or other access device after a maturation period, while other embodiments of the vascular graft may be used immediately following implantation of the graft.
The second body fluid segment may comprise a catheter or other conduit that is adapted to transport blood or other body fluid into the venous system. The second body fluid segment may have a first outer diameter that transitions to a second outer diameter adapted for insertion into a vein. In one embodiment, the second outer diameter may be within the range of about 3 mm to about 10 mm, sometimes within the range of about 4 mm to about 8 mm, and preferably about 5 mm. In some embodiments, the second body fluid segment is designed to be trimmable at the point of use to facilitate further customization of the device to a particular patient. The second body fluid segment may also have an embedded or external spiral support to provide kink resistance.
The selection of the inner diameter, outer diameter and length of the two segments may be selected by one skilled in the art, based upon factors including but not limited to the vein into which the second body fluid segment is being inserted into, the length of catheter to be inserted through the vein wall, as well as the desired flow rate and fluid resistance characteristics.
In one embodiment, the invention further comprises a conduit access or needle access site. The needle access site may be on the catheter and/or the graft, involving direct puncture of the catheter and/graft components with a needle. The invention may further comprise a separate needle access site structure attached to the catheter, graft or to both, using one or more connectors. The conduit access site may be subcutaneous or transcutaneous. Access to the conduit is typically obtained by using needle puncture, but other sealable or valved interfaces capable of non-piercing access are known in the art and may also be used.
In one embodiment, the invention comprises a method of forming an AV hemodialysis graft. A connector system comprising a graft, a catheter and a connector is provided. The first end of the graft is attached to an artery in the body and the second end of the catheter is inserted into the lumen of a vein. The second end of the graft is attached to the first end of the connector and the first end of the catheter is attached to the second end of the connector. The artery may be the radial artery, ulnar artery, brachial artery, axial artery, femoral artery, popliteal artery, anterior tibial artery, posterior tibial artery, dorsalis pedis artery, hypogastric artery, external iliac artery, thoracic aorta, abdominal aorta, common carotid artery, external carotid artery, internal carotid artery, vertebral arteries, renal artery or any other artery where AV anastomosis is desired. The vein may be a cephalic vein, basilic vein, brachial vein, axillary vein, subclavian vein, a pulmonary vein, an innominate vein, internal mammary vein, azygous vein, a basivertebral vein, an intervertebral vein, external jugular vein, internal jugular vein, a vertebral vein, saphenous vein, popliteal vein, femoral vein, deep femoral vein, external iliac vein, common iliac vein, hypogastric vein, the inferior vena cava, the superior vena cava, renal vein, hepatic vein, portal vein or any other vein or a lymphatic duct in the body. In some embodiments of the invention, the connector may be attached to the graft and/or catheter at the point of manufacture. In some embodiments, the connector may be attached to the graft and/or catheter prior to attaching or inserting the graft and/or catheter to the blood vessel, respectively.
While this invention has been particularly shown and described with references to embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention. For all of the embodiments described above, the steps of the methods need not be performed sequentially.
The present application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 60/509,428 filed on Oct. 8, 2003, and to U.S. Provisional Application No. 60/605,681 filed on Aug. 31, 2004, the disclosures of which are incorporated by reference herein in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60509428 | Oct 2003 | US | |
| 60605681 | Aug 2004 | US |
