Patent Application
20090204079
The present invention generally relates to catheters and preferably to multi-lumen catheters used for vascular access.
Multi-lumen catheters are desirable for various treatment applications such as hemodialysis where fluid extraction and return occur simultaneously. Hemodialysis is the separation of metabolic waste products and water from the blood by filtration. Typically, a hemodialysis unit is connected to a patient's body by a catheter. The catheter's distal end is placed in a blood vessel and its proximal end is connected to a hemodialysis unit.
During hemodialysis, a patient's blood typically flows through a double lumen catheter to the hemodialysis unit which provides filtration and controls the flow of blood. A double lumen catheter has two lumens that independently allow fluid extraction and return. For example, one lumen can be used for removing blood from a patient for processing in the hemodialysis machine and the other lumen can be used for subsequently returning the processed blood back to the patient's circulatory system. Such catheters can also include additional lumens for flushing, administration of anticoagulants or the like.
Parameters that can be varied to achieve adequate hemodialysis include blood flow rate, dialysis solution flow rate, and dialyzer competency. Generally, raising the blood flow rate increases dialysis efficiency. However, conditions such as access recirculation decrease efficiency. Access recirculation is the recirculation of treated blood back into the hemodialysis unit. Excess recirculation effectively reduces dialysis efficiency and lengthens the duration of the treatment needed for adequate dialysis. Access recirculation can be particularly of concern when using a double lumen catheter due to the close proximity of the intake and outflow ports at the distal tip of the catheter.
Various double lumen catheter designs have been suggested for the purpose of reducing access recirculation. For example, in so-called “staggered, fixed tip” designs, the distal ends of intake and outflow lumens can be longitudinally spaced 20-30 mm apart to prevent recirculation. For example, Twardowski et al. U.S. Pat. No. 5,569,182 discloses that the lumen for return of blood back into the vein should terminate beyond the extraction lumen. The purpose of this is to prevent cleansed blood, exiting from the outlet point of the catheter, from re-entering the catheter's blood inlet point and returning to the dialysis machine. However, certain disadvantages have been noted by such large longitudinal spacing between the distal ends of the respective lumens. For example, blood flow stagnation in the region of the blood vessel between two widely separated tips can lead to clot formation.
In addition to longitudinal spacing of the distal openings of the lumens, others have suggested that the distal end of a multi-lumen catheter can be split such that the distal tip segments can independently move in the blood vessel to optimize the fluid dynamics of the different functions (blood extraction and blood return). The introduction of an angle between the extraction and return lumens of a split tip catheter can further reduce the likelihood of access recirculation due to greater separation between inflow and outflow lumens.
Moreover, it can be desirable to have the maximum possible luminal cross-sectional areas to optimize catheter flow characteristics and also to maintain adequate flow over time since flow rates tend to decrease due to factors such as catheter clotting. However, there exists a need to maintain adequate physical and mechanical properties of the catheter, for instance tensile strength and kink-resistance, and to keep overall catheter dimensions small enough for insertion and proper physiological function. With these constraints in mind, it can be advantageous to have a different shape, e.g., greater luminal cross-section, for one or the other of the lumens or split tip segments, for example, to facilitate blood withdrawal or to diffuse returning cleansed blood. In particular, the arterial (or extraction) lumen is more prone to clogging and can benefit from having a larger cross-section. However, such geometric differences are difficult to incorporate into catheters using conventional manufacturing techniques.
While various catheters are known, there exists a need for more efficient and economical catheters, especially catheters where the distal openings of the lumens are longitudinally spaced or a different shape or geometry is desired for one or the other of the lumens or tip segments.
Asymmetric lumen catheter devices are disclosed. In one embodiment of the invention, a catheter assembly includes a first elongate catheter tube having a substantially D-shaped cross-section over at least a portion of its length and having a first lumen extending longitudinally through the first catheter tube and a second elongate catheter tube adjacent to the first catheter tube. The second catheter tube extends a longitudinal length beyond a distal end of the first catheter tube, has a substantially D-shaped cross-section over at least a portion of its length, and has a second lumen extending longitudinally therethrough. The first lumen has a larger cross-sectional size than the second lumen over at least a portion of its length.
The catheter assembly can vary in any number of ways, such as by at least one of the tubes including a plurality of fluid passage holes. In some embodiments, at least one fluid passage hole can be formed in a side of a distal portion of at least one of the tubes, while in some embodiments, a hole can be formed at a distal end of at least one of the tubes.
The tubes can have a variety of configurations. For example, the tubes can be a unibody construction with the first and second lumens separated by a longitudinal septum. As another example, the tubes can be discrete elements where a longitudinal length of the first tube is attached to a portion of a longitudinal length of the second tube. The tubes can be fused along at least about 10%, preferably along at least about 50%, more preferably in some applications along at least about 70%, 80%, or 90% of the longitudinal lengths.
The distal and proximal portions of the catheter assembly can have any combination of split and fixed tips. For example, proximal portions of the tubes can be separate from each other.
The catheter assembly can include a variety of other features. For example, in some embodiments, the catheter assembly includes a lumen tip segment joined to a distal end of at least one of the tubes such that the lumen tip segment is in communication with the lumen of the tube to which it is joined. As another example, an outer sheath can encase the tubes along at least a portion of longitudinal lengths of the tubes. As yet another example, a flow diverting structure can be attached to an outside surface of a distal portion of the second catheter tube.
In another aspect of the invention, a catheter assembly includes two tubes, each tube having a lumen extending longitudinally therethrough and one tube having a larger luminal cross-sectional size than the other tube over at least a portion of their lengths. The tubes can be disposed adjacent to each other along at least a portion of respective longitudinal lengths of the tubes such that a distal portion of one tube extends longitudinally beyond a distal portion of the other tube. The catheter assembly also includes a flow diverting structure attached to the distal portion of the tube that extends longitudinally beyond the other tube.
The catheter assembly can vary in any number of ways, such as by at least one of the tubes including a plurality of fluid passage holes. In some embodiments, at least one fluid passage hole can be formed in a side of a distal portion of at least one of the tubes, while in some embodiments, a hole can be formed at a distal end of at least one of the tubes.
The tubes can have a variety of shapes, sizes, and configurations. For example, the tubes can be a unibody construction having a longitudinal septum extending therethrough. As another example, the tubes can be attached together along at least about 10%, preferably along at least about 50%, more preferably in some applications along at least about 70%, 80%, or 90% of the longitudinal lengths. In some embodiments, the tubes can each have at least one flat surface and be attached together along their flat surfaces. As another example, an outer sheath can encase the tubes along at least a portion of their longitudinal lengths.
The distal and proximal portions of the catheter assembly can have any combination of split and fixed tips. For example, proximal and/or distal portions of the tubes can be separate from each other.
The tubes can have any cross-sectional shape (e.g., substantially D-shaped, circular, etc.) and can have a cross-sectional shape the same as or different from the other tube along at least a portion of its longitudinal length.
The flow diverting structure can be attached to the distal portion of the tube (“the longer tube”) that extends longitudinally beyond the other tube (“the shorter tube”) in a variety of ways. For example, the diverting structure can be fused or glued to the longer tube.
The flow diverting structure can have a variety of shapes, sizes, and configurations. For example, the flow diverting structure can be oriented to intersect a longitudinal axis of the tube to which it is not attached. For another example, the flow diverting structure can have a diameter that does not exceed a diameter of the tube to which it is not attached. As another example, the flow diverting structure can be attached at a location between distal ends of the tubes.
The flow diverting structure can be composed of a variety of materials. For example, the diverting structure can be composed of a material different than a material of the tube to which it is attached, such as a material with a durometer that differs from that of the tube to which it is attached.
In another aspect of the invention, a catheter assembly includes first and second catheter tubes having first and second inner lumen extending longitudinally therethrough, respectively. The second catheter tube has a length greater than a length of the first catheter tube, and the first inner lumen has a cross-sectional size that is larger than a cross-sectional size of the second inner lumen. A distal portion of the first inner lumen has a cross-sectional size that is different from the cross-sectional size in its non-distal portion.
The tubes can have a variety of configurations. For example, the tubes can be a unibody construction with the first and second lumens separated by a longitudinal septum. As another example, the tubes can be discrete elements where a longitudinal length of the first catheter tube is attached to a portion of a longitudinal length of the second catheter tube.
The tubes can have any cross-sectional shape (e.g., substantially D-shaped, circular, etc.). The cross-sectional size of the distal portion of the first inner lumen can be larger than the cross-sectional size in its non-distal portion.
The inner lumens can have any cross-sectional shape (e.g., substantially D-shaped, circular, etc.). In some embodiments, one of the first and second inner lumens can have a cross-sectional shape different from the other inner lumen along at least a portion of its longitudinal length.
The catheter assembly can vary in any number of ways, such as by at least one of the tubes including a plurality of fluid passage holes. In some embodiments, at least one fluid passage hole can be formed in a side of a distal portion of at least one of the tubes, while in some embodiments, a hole can be formed at a distal end of at least one of the tubes.
The distal and proximal portions of the catheter assembly can have any combination of split and fixed tips. For example, proximal and/or distal portions of the tubes can be separate from each other.
The catheter assembly can include a variety of other features. For example, in some embodiments, the catheter assembly includes a lumen tip segment joined to a distal end of the first catheter tube such that the lumen tip segment is in communication with the first inner lumen. As another example, an outer sheath can encase the tubes along at least a portion of longitudinal lengths of the tubes. As yet another example, a flow diverting structure can be attached to a distal portion of the second catheter tube.
Other advantages and features will become apparent from the following description and from the claims.
The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which like reference numerals designate like parts throughout the figures, and wherein:
In
The first pathway 106a is of a smaller size (e.g., smaller cross-sectional area) than the second pathway 106b. Either of the pathways 106 can have a larger cross-sectional area than the other pathway, but the larger pathway is typically in the shorter, arterial tube 104b because that is the one of the tubes 104 more prone to clogging in a hemodialysis setting, and a larger size pathway 106b can help reduce clogging. The pathways 106 can have different diameters or heights, such as in the illustrated embodiment where a diameter D2 of the second pathway 106b exceeds a diameter D1 of the first pathway 106a. The tubes 104 can also have different sizes (e.g., cross-sectional areas). Either of the tubes 104 can have a larger size, but in this embodiment, a diameter or height H2 of the second tube 104b exceeds a height H1 of the first tube 104b. Although the tubes 104 and the pathways 106 are shown having equal widths Wt and Wp, respectively, the tubes 104 and/or the pathways 106 can have different widths. In some embodiments, the pathways 106 can have the same diameter but still have different cross-sectional areas, e.g., by varying one or both of the tube and pathway widths Wt, Wp.
The catheter assembly 100 has fixed tip distal and proximal portions 114, 116, although the catheter assembly 100 can have any combination of fixed tips and split tips at its distal and proximal portions 114, 116. An outer sheath can be added to at least a portion of the catheter assembly 100, as discussed further below, and/or access ports can be added to the tubes 104 at the proximal portion 116. The access ports can include couplings, such as Luer-locks or the like, to couple the proximal portion 116 to a hemodialysis machine in which blood is circulated and purified. The catheter assembly 100 is typically a very flexible silicone, polyurethane, or other biocompatible composition (e.g., having a stiffness in the range of about 65 to about 85 durometer), and can be fabricated into any type of catheter (e.g., a hemodialysis catheter or a central venous catheter).
The catheter assembly 100 can be formed in a variety of ways. In some embodiments, the catheter assembly 100 can be formed by trimming one of the tubes 104 to a longitudinal length less than a longitudinal length of the other tube. In other embodiments, the tubes 104 can be attached together to form the catheter assembly 100. For example, in one embodiment, the tubes 104 can be fused along at least a portion of their longitudinal lengths along substantially flat surfaces, such as the contacting surfaces 110 of the tubes 104. Any fusion technique can be used, e.g., thermal fusion where elements to be joined (here, outer surfaces of the tubes 104) are heated along any or all portions of their perimeters or other areas to a desired temperature and fused together by application of a desired force and allowing them to melt/cool together. In another example embodiment, the tubes 104 can be fused together using a bonding technique, e.g., applying a bonding material such as an adhesive to one or more of the elements to be bonded and, if necessary, heating the bonding material to bond it to the elements. In some embodiments, the catheter assembly 100 can be formed using any combination of heat fusion and bonding techniques. Whether or not the tubes 104 have equal longitudinal lengths, the catheter assembly 100 can be formed by extending the tubes 104 in a staggered, step configuration such that one of the tubes 104 extends longer than the other tube at the distal portion 114 and/or the proximal portion 116 by any length. By non-limiting example, the tubes 104 can be aligned while hot so at least one of the tubes 104 longitudinally extends beyond the other at the distal and/or proximal portions 114, 116 and can bond together in such a formation as they cool.
In some embodiments, a lumen tip segment of any length can be joined to one of the tubes 104 such that the distal portion 114 of that tube 104 includes the lumen tip segment, such that the lumen tip segment is in fluid communication with the pathway 106 of the tube to which the lumen tip segment is attached, and such that the longer tube 104a extends the length L beyond the distal end 108b of the shorter tube 104b. Prior to joining the lumen tip segment to one of the tubes 104, that tube 104 can be trimmed, as discussed further below.
Any portion of each of the tubes 104 can be attached together, e.g., 100% of the longitudinal lengths of one or both tubes 104, about 90% of the longitudinal lengths of one or both tubes 104, etc. If less than 100% of the tubes' longitudinal lengths are attached together, the resulting catheter assembly 100 can be used to create a split tip catheter, e.g., by adding one or more additional structures to the catheter assembly 100. As illustrated in
The catheter assembly embodiments illustrated in
Also illustrated in
In an embodiment shown in
The bioresorbable adhesive used to join the tubes 104 to one another can be a composition selected from the group of polymers consisting of polylactides, polyglycolides, polylactones, polyorthoesters, polyanhydrides, and copolymers and combinations thereof. In general, bioresorbable adhesives have bonding elements and degradable elements. The degradable elements can have the components of polylactide, polyglycolide and polylactones (polycaprolactone). The bonding elements can have hydrogen bonding strength (polyvinyl alcohol, polysaccharides) or can be able to polymerize as a single component (cyanoacrylates) or as two components (epoxy compound plus amino compounds, or radical (light) initiators of acrylate compounds).
Proteins, sugars, and starch can also be used as an adhesive. By way of non-limiting example, antithrombotic agents such as heparin and hirudin, citrate, antithrombin-heparin complex, and albumin heparin complex as well as anti-infective agents such as chlorohexidine, silver, antibiotics, and antiseptic agents may be added to the adhesive.
In an embodiment of the present invention, polymers which can be useful include polyurethane, generally described as a copolymer of polyethylene glycol with polylactide or polyglycolide end capped with methacrylates. Another embodiment can include a two component composition, one component preferably including a low molecular weight polyurethane end capped with methacrylates, and the other component preferably including polylactide, polyglycolide, or polycaprolactone end capped with methacrylate.
In another embodiment of the present invention, one or more components can be used from styrene, methyl methacrylate, methyl acrylate, ethylene dimethacrylate, ethylene diacrylate, acrylamide, diurethane dimethacrylate, polyisoprenegraft-maleic acid monomethyl ester, azobis (cyanovaleric acid), azobiscyclohexanecarbonitrile, azobisisobutyronitrile, benzoyl peroxide, iron (II) sulfate, polyvinyl alcohol, dextran, polysaccharide, epichlorohydrin, ethylenediamine, diaminocyclohexane, diamino propane, copolymers with polylactide and polyethylene oxide as the blocks and acrylate, methacrylate as the end groups, cyanoacrylates, ethyl-2cyanoacrylate, propyl-2-cyanoacrylates, pentyl-2-cyanoacrylate, hexyl-2-cyanoacrylate, and octyl-2-cyanoacrylate, ammonium persulfate and/or polyethylene glycol methacrylate when water, organic solvent such as dichloromethane, chloroform, tetrahydrofuran, acetone, petroleum ether, acetyl acetate, dimethylformamide, or the mixture thereof, is combined with the aforementioned solvents.
Additional information on bioresorbable adhesive compositions and catheter assembly manufacturing techniques employing such compositions can be found in commonly-owned, co-pending U.S. patent application Ser. No. 10/874,298 filed Jun. 9, 2004 entitled “Splitable Tip Catheter With Bioresorbable Adhesive”, herein incorporated by reference in it entirety.
The spots 120 of the bioresorbable adhesive can be applied continuously along the entire longitudinal length of the tubes 104 or selectively in an assortment of areas thereof. Preferably, the bioresorbable adhesive is applied such that the spots 120 of adhesive facilitate the joining of the distal portions 114 of the tubes 104 prior to insertion into a blood vessel and allow the distal portion 114 of the tubes 104 to separate after insertion. The spots 120 of bioresorbable adhesive can vary in number, size, and distance from one another in order to facilitate the joining and/or disjoining of the tubes 104. Preferably, the bioresorbable adhesive is applied along non-fused portions of both of the facing surfaces 110 such that the spots 120 of adhesive facilitate the joining of the tubes 104 prior to insertion into a blood vessel and allow the distal portions 114 of the tubes 104 to separate after insertion. Also preferably, if a lumen tip segment is attached to one of the tubes 104, the bioresorbable adhesive is applied prior to attachment of the lumen tip segment.
In the embodiments described herein, the bioresorbable adhesive preferably dissolves after insertion into a blood vessel to provide separation of the tubes 104 in a time period, e.g., over a period of time ranging from 1 second to several days (or longer), more preferably from about one minute to about ten hours, or five hours or one hour. This time period can be controlled by using different compositions of the bioresorbable adhesive as well as by the amount of adhesive applied to join the tubes 104 together. In an embodiment of the catheter assembly 100 with one or more distal fluid openings 112, the bioresorbable adhesive can be water soluble such that the introduction of saline or similar type fluid will effectuate the separation of the tubes 104 and exposure of one or more of the fluid openings 112. In this instance, the bioresorbable adhesive will not dissolve until a time after the introduction of the soluble solution into the tubes 104. Furthermore, the fluid openings 112 can be filled or covered with fluid activated bioresorbable adhesive, whether or not bioresorbable adhesive is otherwise used on the facing surfaces 110 of the tubes 104. After insertion of the catheter assembly 100 into a blood vessel, saline or similar type fluid can be introduced into one or both of the tubes 104 at the open proximal portion 116 such that the fluid travels through the tube(s) 104 to the distal fluid openings 112 and dissolves the fluid activated bioresorbable adhesive, thereby allowing fluid communication between the openings 112 and the lumen pathway(s) 106. The openings 112 are obscured on the shorter tube 104b until such time one or more of the spots 120 of adhesive dissolve and provide fluid access to one or more of the openings 112. Of course, depending on the lengths of the tubes 104, one or more openings 112 on both of the tubes 104 could be obscured until such time one or more of the spots 120 dissolve and/or adhesive filling or covering the openings 112 dissolves.
The tubes 104 can have a variety of cross-sectional shapes and sizes but preferably, as shown in the embodiments of
Examples of c1-c1 cross-sections (see
As mentioned above, an outer sheath, e.g., a fusing tube, can be added to partially or entirely cover and enclose the catheter assembly 100. Such an outer sheath can encase the catheter assembly 100 and smoothen any irregularities along at least part of the attached portion of the longitudinal lengths of the tubes 104. The outer sheath can be any shape and size and can be made of the same material as the tubes 104 or other material compatible with insertion into a blood vessel. The outer sheath can remain on or be removed from at least a portion of the catheter assembly 100.
As mentioned above, the catheter assembly 100 can be formed by attaching the tubes 104 together. Additional information on such catheter assemblies and catheter assembly manufacturing techniques can be found in commonly-owned, co-pending U.S. patent application Ser. No. ______ filed concurrently herewith entitled “Fusion Manufacture of Multi-Lumen Catheters” (Attorney Docket No. 101430-236).
Also as mentioned above, in some embodiments, the catheter assembly 100 can be formed by trimming one of the tubes 104 such that at the distal end 114 one of the tubes 104b is shorter than the other one of the tubes 104a. Additional information on such catheter assemblies and catheter assembly manufacturing techniques can be found in commonly-owned, co-pending U.S. Provisional Application Ser. No. 60/980,633 filed Oct. 17, 2007 entitled “Manufacture of Split Tip Catheters.” An exemplary method of forming a catheter is described with reference to
The cut tube 104b can be trimmed in a variety of ways. In a preferred example, one of the tubes 104b can be sliced (e.g., cut or scored) widthwise across its circumference at a location 128. Then the length L of the cut tube 104b can be trimmed from the catheter assembly 100. When the length L of the cut tube 104b has been removed, a septum 130 between the cut tube 104b and the uncut tube 104a can thereby be at least partially exposed.
Truncation of the end portion according the invention typically involves sacrificing part of the tube 104b having a larger cross-sectional area and joining a new distal tip segment in its place. As illustrated for example in
In certain applications it can be preferable to sacrifice the smaller tube 104a instead. In such instances, the truncation line can be moved to the other side of the septum 107.
The cut distal end 128 of the cut tube 104b can be trimmed in a perpendicular direction or a non-perpendicular direction with respect to a longitudinal axis β of the cut tube 104b.
With a distal portion of the catheter assembly 100 removed, the lumen tip segment 132 can be joined to the catheter assembly 100, as shown in
Referring again to
The lumen tip segment 132 can be oriented at any angle with respect to the longitudinal axis β of the cut tube 104b. Moreover, one or both of the lumen tip segment 132 and the distal tip portion 102a of the longer tube 104a (The tube to which the lumen tip segment 132 is not attached) can have a convex shape with respect to the other over at least some portion of its length. For example, the lumen tip segment 132 can be attached to the cut tube 104b at a ninety degree angle θ′ with respect to axis β, as shown in
The apex of angle σ can be located either at the junction of the cut tube 104b and the lumen tip segment 132, as shown in
Whether substantially parallel or diverging from one another, the distal tip portion 102a and the lumen tip segment 132 are separate (at least before application of any adhesive, discussed further below).
Regardless of how the catheter assembly 100 is formed or whether a lumen tip segment is attached to one or both of the tubes 104, a flow diverting structure can be attached to the longer one of the tubes 104. Additional information on flow diverting structures and manufacturing techniques for catheters including flow diverting structures can be found in commonly-owned, co-pending U.S. patent application Ser. No. ______ filed concurrently herewith entitled “Manufacture of Fixed Tip Catheters” (Attorney Docket No. 101430-240).
The flow diverting structure 142 has been attached to an outside surface of the longer tube 104a between the tubes' distal ends 108a, 108b, e.g., on the longer tube's facing surface 110a in the distal tip portion 102a. Examples of the diverting structure 142 are disclosed in Siegel, Jr. et al. U.S. Pat. No. 6,409,700. The diverting structure 142 can be attached anywhere on the longer tube 104a such that the diverting structure 142 is oriented to divert fluid flowing out of the pathway 106a at the distal end 108a of the longer tube 104a away from the pathway 106b at the distal end 108b of the shorter tube 104b. For example, the diverting structure 142 can be attached on the facing surface 110a of the longer tube 104a to intersect a longitudinal axis A of the shorter tube 104b. In this way, the diverting structure 142 can at least partially obscure a predicted path of fluid flowing into the distal end 108b of the shorter tube 104b. The diverting structure 142 is typically attached so its proximal end 144 is a distance D from the distal end 108b of the shorter tube 104b so as to provide adequate space for fluid to flow into the shorter tube 104b. The distance D can have any positive value less than the length L between the distal ends 108 of the tubes 104.
The diverting structure 142 can be attached to the longer tube 104a in a variety of ways. For example, in one embodiment, the diverting structure 142 can be fused to the longer tube 104a along at least a portion of a substantially flat surface (e.g., a facing or contacting surface 148) of the diverting structure 142 and along at least a portion of an outside surface of the longer tube 104a (e.g., on the facing surface 110a along a portion of the length L). Any fusion technique can be used, e.g., thermal fusion where elements to be joined (here, facing surfaces 110a, 148 of the longer tube 104a and the diverting structure 142, respectively) are heated along any or all portions of their perimeters or other areas to a desired temperature and fused together by application of a desired force and allowing them to melt/cool together. In another example embodiment, the diverting structure 142 and the longer tube 104a can be attached together using a gluing technique, e.g., applying a bonding material such as an adhesive to one or more of the elements to be bonded and, if necessary, heating the bonding material to bond it to the elements. In some embodiments, the catheter assembly 100 can be formed using any combination of heat fusion and gluing techniques.
The diverting structure 142 can be made of any biocompatible material which allows it to maintain structural integrity when in contact with flowing fluid, such as when inserted in a blood vessel during hemodialysis. The diverting structure's material can be the same as or different from that of the longer tube 104a and/or the shorter tube 104b. Using a different material for the diverting structure 142 (e.g., a harder material having a higher durometer) than for one or both of the tubes 104 can help create a more predictable fluid flow path by reducing chances of the diverting structure 142 flexing, bending, or otherwise distorting when being inserted into a fluid flow path (e.g., a blood vessel) and when fluid flows against the diverting structure 142.
The distal ends 108 of the tubes 104 can each have any angle α1, α2 with respect to the transverse axes A2 of the tubes 104. The values of the angles α1, α2 can be the same or different. In the embodiment illustrated in
As shown in
Examples of c3-c3 cross-sections (see
Although the examples of c3-c3 cross-sections in
Prior to the distal ends 108 of the catheter assembly 100 being inserted into a blood vessel, any or all portions of the distal tip portion 102 can be coated with at least one agent, such as an antithrombotic agent, an antibacterial agent, and an anti-inflammatory agent. By way of non-limiting example, antithrombotic agents such as heparin and hirudin, citrate, antithrombin-heparin complex, and albumin heparin complex as well as anti-infective agents such as chlorohexidine, silver, antibiotics, and antiseptic agents can be used. The agent can be applied along the distal tip portion 102 as a continuous coating or as a coating in discrete spots or regions. The spots or regions can vary in number, size, and distance from one another.
Other embodiments are within the scope of the following claims.
All publications, patent documents and other information sources identified in this application are hereby incorporated by reference.
The present application claims the priority of U.S. Provisional Application Ser. No. 60/980,633 filed Oct. 17, 2007 entitled “Manufacture of Split Tip Catheters” and U.S. Provisional Application Ser. No. 61/029,030 filed Feb. 15, 2008 entitled “Catheters With Enlarged Arterial Lumens,” which are herein incorporated by reference in their entireties. This application is also related to commonly owned U.S. patent application Ser. No. ______ filed concurrently herewith entitled “Fusion Manufacture of Multi-Lumen Catheters” (Attorney Docket No. 101430-236), and U.S. patent application Ser. No. ______ filed concurrently herewith entitled “Manufacture of Fixed Tip Catheters” (Attorney Docket No. 101430-240), each of which are herein incorporated by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 61029030 | Feb 2008 | US | |
| 60980633 | Oct 2007 | US |
