US20100168717A1 - Multi-lumen medical devices and methods of manufacturing same - Google Patents

Abstract

A method of manufacturing a catheter shaft includes extruding an inner polymeric layer having a main lumen and two or more side lumens spaced about the main lumen; forming an outer polymeric layer about the inner polymeric layer; and inserting at least one elongate member, such as a wire, through each side lumen of the inner polymeric layer. The side lumens are less than about ⅕ the size of the main lumen. The method may further include the step of forming a braided layer between the inner polymeric layer and the outer polymeric layer. In an alternate embodiment, the method includes co-extruding an inner polymeric layer and a multi-lumen layer, the multi-lumen layer having two or more side lumens; forming an outer polymeric layer about the multi-lumen layer; and inserting at least one elongate member through each side lumen. Catheter assemblies made according to the described methods are also disclosed.

Description

BACKGROUND OF THE INVENTION
• a. Field of the Invention
• The present invention pertains generally to electrophysiological devices having multiple lumens and methods for manufacturing multi-lumen electrophysiological devices. More particularly, the invention is directed to catheters and introducers and methods for manufacturing catheters and introducers having multiple, integrally-formed or co-extruded side lumens for enclosing elongate members, such as steering wires and electrical wires.
• b. Background Art
• Catheters are used for an ever-growing number of procedures. For example, catheters are used for diagnostic, therapeutic, and ablative procedures, to name just a few examples. Typically, the catheter is manipulated through a patient's vasculature and to the intended site, for example, a site within the patient's heart. The catheter typically carries one or more electrodes, which may be used for ablation, diagnosis, or the like.
• Many catheters include one or more wires, for example, pull wires for steering and deflecting the catheter and/or electrical wires for energizing electrodes or other energy delivery or diagnostic elements. In some catheters, the wires are enclosed in small, polymeric liners or jackets that surround a main liner or jacket. The small jackets are manufactured separately from the main jacket and are subsequently glued along the length of the main jacket. The gluing process is time-consuming and can be inefficient. The small jackets must be glued substantially straight along the length of the main jacket; otherwise, steerable devices will not deflect properly. Also, the process becomes more time-consuming for devices using greater numbers of wires because greater numbers of small jackets must be glued along the length of the main jacket.
• Accordingly, there is a growing need for improved catheters and improved methods for manufacturing catheters having liners or jackets that enclose the various wires to eliminate the time-consuming and inefficient gluing process.
BRIEF SUMMARY OF THE INVENTION
• The present invention provides for medical devices and methods of manufacturing medical devices having multiple, integrally-formed side lumens enclosing elongate members, such as steering wires and electrical wires. The present invention also provides for medical devices and methods of manufacturing medical devices having a multi-lumen layer co-extruded with an inner layer.
• An objective of the present invention is to provide methods of manufacturing a catheter assembly having multiple side lumens integrally-formed with a main lumen.
• Another object of the invention is to provide methods of manufacturing a catheter assembly having an extruded polymer layer comprising a main lumen and multiple side lumens arranged about the main lumen.
• Still another object of the present invention is to provide methods of manufacturing a catheter assembly having an inner polymeric layer co-extruded with a multi-lumen layer.
• Yet another object of the present invention is to provide medical devices manufactured by the methods described herein.
• A method of manufacturing a catheter assembly includes the steps of extruding an inner polymeric layer, the inner polymeric layer defining a main lumen having an inner surface and an outer surface and further defining two or more side lumens spaced about the outer surface of the main lumen. In one aspect, a size of the side lumens is less than about ⅕ to about 1/16 a size of the main lumen. The method further includes forming an outer polymeric layer disposed about the inner polymeric layer and inserting at least one elongate member through each side lumen of the inner polymeric layer. The elongate member may be a wire, such as a pull wire or an electrical wire.
• The method may optionally include the step of forming a braided layer between the inner polymeric layer and the outer polymeric layer. The inner polymeric layer, the braided layer and the outer polymeric layer may be heated to bond the inner polymeric layer, the braided layer and the outer polymeric layers together. The inner polymeric layer may be made of polytetrafluoroethylene. The side lumens may be spaced symmetrically about the outer surface of the main lumen or may be spaced in any other orientation. In one aspect, the inner polymeric layer includes about 2-16 side lumens.
• In another embodiment of the present invention, a method of manufacturing a catheter assembly includes co-extruding an inner polymeric layer and a multi-lumen layer. The inner polymeric layer includes an inner surface defining a main lumen and an outer surface, and the multi-lumen layer includes two or more side walls, each side wall defining a side lumen. The method further includes forming an outer polymeric layer about the multi-lumen layer and inserting at least one elongate member through each side lumen. The method may optionally include a step of forming a braided layer between the multi-lumen layer and the outer polymeric layer. The inner polymeric layer, the multi-lumen layer, the braided layer and the outer polymeric layer may also be heated to bond the layers together.
• The inner polymeric layer and the multi-lumen layer may be made of the same or different materials. In one aspect, the inner polymeric layer and the multi-lumen layer are made of polytetrafluoroethylene. A size of the side lumens may be less than about ⅕ to about 1/16 a size of the main lumen. The multi-lumen layer may include about 2-16 side lumens, which may be spaced symmetrically about the outer surface of the main lumen, or in any other orientation. The elongate member may be a wire, such as a pull wire or an electrical wire.
• In yet another aspect of the present invention, a catheter assembly includes an inner extruded polymeric layer and an outer polymeric layer disposed about the inner extruded polymeric layer. The inner extruded polymeric layer includes a main lumen having an inner surface and an outer surface and two or more side lumens spaced about the outer surface of the main lumen. The device further includes at least one elongate member extending through one of the side lumens. In one embodiment, a braided layer may be disposed between the inner extruded polymeric layer and the outer polymeric layer. In one aspect, a size of the side lumens may be less than about ⅕ to about 1/16 a size of the main lumen. The side lumens may be spaced symmetrically about the outer surface of the main lumen, or in a non-symmetrical orientation. The inner extruded polymeric layer may include about 2-16 side lumens. The inner extruded polymeric layer may be made of polytetrafluoroethylene. In one embodiment, the elongate member may be a wire, such as a pull wire or an electrical wire.
• In still another aspect of the present invention, a catheter assembly includes an inner polymeric layer having an inner surface defining a main lumen and having an outer surface and a multi-lumen layer disposed about the outer surface of the inner polymeric layer. The multi-lumen layer includes two or more side walls, each side wall defining a side lumen. The multi-lumen layer and the inner polymeric layer are co-extruded. The catheter shaft further includes an outer polymeric layer disposed about the multi-lumen layer and at least one elongate member extending through one of the side lumens. In one embodiment, a braided layer may be disposed between the multi-lumen layer and the outer polymeric layer. A size of the side lumens may be less than about ⅕ to about 1/16 a size of the main lumen. The multi-lumen layer may include about 2-16 side lumens. The side lumens may spaced symmetrically about the outer surface of the main lumen or in a non-symmetrical orientation. In one embodiment, the elongate member may be a wire, such as a pull wire or an electrical wire.
• An advantage of providing medical devices having multiple, integrally-formed lumens for enclosing elongate members is a shorter manufacturing process.
• Another advantage of providing medical devices having multiple, integrally-formed lumens for carrying elongate members is a more efficient manufacturing process and fewer product defects.
• The foregoing and other aspects, features, details, utilities, and advantages of the present invention will be apparent from reading the following description and claims, and from reviewing the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view of a catheter according to an embodiment of the present invention.
• FIGS. 2A-D depict cross-sectional views of various embodiments of an inner layer of a catheter assembly according to the invention.
• FIG. 3 is a cross-sectional view of a catheter assembly having an inner layer as depicted inFIG. 2A, prior to the application of heat to melt process the outer layer.
• FIG. 4 depicts a cross-sectional view of a catheter assembly having an inner layer as depicted inFIG. 2A, after the application of heat to melt process the outer layer.
• FIG. 5 is a cross-sectional view of a catheter assembly having multiple integrally-formed side lumens with pull wires and electrical wires extending through the side lumens.
• FIG. 6 depicts a cross-sectional view of an inner layer of a catheter assembly according to another embodiment of the present invention.
• FIG. 7 illustrates a cross-sectional view of a catheter assembly having a multi-lumen layer as depicted inFIG. 6, prior to the application of heat to melt process the outer layer.
• FIG. 8 is a cross-sectional view of a catheter assembly having a multi-lumen layer as depicted inFIG. 6, after the application of heat to melt process the outer layer.
• FIG. 9 depicts is a cross-sectional view of a catheter assembly having a co-extruded multi-lumen layer with pull wires and electrical wires extending through the side lumens of the multi-lumen layer.
DETAILED DESCRIPTION OF THE INVENTION
• Disclosed herein are medical devices and methods of manufacturing medical devices, for example catheters and introducers, having multiple side lumens integrally-formed or co-extruded with a main lumen. The side lumens enclose elongate members, for example steering wires and electrical wires. The present invention provides catheters and methods of manufacturing catheters suitable for use in the human vasculature for known medical procedures, such as cardiac diagnostic and therapeutic procedures including, without limitation, electrophysiological mapping and cardiac ablation. It is contemplated, however, that the described features may be incorporated into any number of catheters or other devices, such as steerable introducers, as would be appreciated by one of ordinary skill in the art.
• FIG. 1 is a perspective view of one embodiment of acatheter12 of the present invention.Catheter12 has aproximal portion16 and adistal portion14.
• One method of manufacturing acatheter12 according to the present invention will be described with reference toFIGS. 3-5. As they are assembled, the catheter components will be collectively referred to as a catheter assembly.
• FIG. 3 displays a cross-section of acatheter assembly12 prior to melt-processing of the layers by heating. Amandrel10 may be the first component during manufacture of thecatheter assembly12. Themandrel10 may be round in cross-section and may be from about 6 inches to about 4 feet in length. Themandrel10 has a distal end and a proximal end. A first orinner polymeric layer20 is placed onmandrel10.Inner polymeric layer20 may be knotted at one end (e.g. the distal end) and then fed ontomandrel10.
• Several embodiments of theinner polymeric layer20 are depicted inFIGS. 2A-D. In general, theinner polymeric layer20 includes amain lumen11 having aninner surface13 and anouter surface15. Theinner polymeric layer20 further includes multiple integrally-formedside lumens30 spaced about theouter surface15 of themain lumen11. As a person of skill in the art will understand, however, the integrally-formedside lumens30 may alternatively be spaced about theinner surface13 of themain lumen11. Theside lumens30 may be spaced symmetrically about the main lumen11 (see, for example,FIG. 2A), but need not be in a symmetrical orientation (see, for example,FIG. 2C).
• Theinner polymeric layer20 is an extruded polymer. In one embodiment, theinner polymeric layer20 is an extruded polytetrafluoroethylene (PTFE) tubing, such as Teflon® brand tubing, which is available commercially. Theinner polymeric layer20 may optionally be chemically etched to provide better adhesion during melt processing. As a person of skill in the art will appreciate, theinner polymeric layer20 may be extruded from other melt processable polymers, including, without limitation, polyetheretherketone (PEEK), polyimides, polyesters, polyamides, polysulfones, polyketones, other fluoropolymers, and the like. In one aspect, theinner polymeric layer20 uses PTFE as a coating over another polymer material, for example, a polyimide extrusion lined with PTFE. In another aspect, theinner polymeric layer20 is made of a material with a melting temperature higher than that of anouter layer50, which will be further described below, such that theinner polymeric layer20 will withstand melt processing of theouter layer50.
• In one aspect, theside lumens30 are about ⅕ the size of the main lumen11 (see, for example,FIGS. 2A-C). In another aspect, theside lumens30 may be about 1/16 the size of themain lumen11 or smaller (see, for example,FIG. 2D). Theside lumens30 are sized to conformably enclose at least one elongate member, for example a pull wire or an electrical wire, while facilitating at least some movement of the elongate member within theside lumen30 and at the same time minimizing friction caused by movement of the elongate member within theside lumen30. A person of skill in the art will appreciate that theside lumens30 can be sized and shaped to accommodate elongate member of various dimensions and cross-sectional configurations. Theside lumens30 need not have the same shape as the cross-section of the elongate members that they encase. Theside lumens30 may be round, oval, rectangular, or another like shape.
• As shown inFIG. 2B,inner polymeric layer20 may include twoside lumens30. Theside lumens30 may be spaced in an opposing orientation as shown inFIG. 2B, or may be spaced in any other orientation about the circumference of themain lumen11. For example, theside lumens30 may be immediately adjacent one another or may be spaced about the circumference of themain lumen11 by about 45 degrees, by about 90 degrees or more. In another aspect, theinner polymeric layer20 includes more than twoside lumens30. For example, theinner polymeric layer20 may include up to 8 side lumens, up to 16 side lumens or more than 16 side lumens (see, for example,FIGS. 2A-D). As a person of skill in the art will understand, theinner polymeric layer20 can be modified to accommodate various numbers of elongate members having various dimensions and cross-sectional configurations.
• As further shown inFIGS. 2A-2D, in one aspect, theinner polymeric layer20 has a scalloped or ribbed profile. This structure is particularly advantageous for steerable devices because it provides greater flexibility. The amount of space betweenadjacent side lumens30 may vary depending on the number of side lumens present and the location of the side lumens about themain lumen11.
• Referring again toFIG. 3, the extrudedinner polymeric layer20 is placed on themandrel10. A small diameter mandrel or set-up wire90 may be placed within theside lumens30 to maintain the integrity of the side lumens during processing. Alternatively, a pull wire may be inserted through one or more of theside lumens30 in lieu of asmall diameter mandrel90. In still other embodiments, theside lumens30 may be maintained during processing via the use of a pressurized fluid as described in U.S. patent publication no. US 2006/0151923, which is incorporated herein by reference in its entirety.
• Anouter polymeric layer50 is then placed over theinner polymeric layer20. Theouter polymeric layer50 may be made of either single or multiple sections of tubing that may be either butted together or overlapped with each other. In one aspect, theouter polymeric layer50 is made of a melt-processable polymer, such as polyether block amides, nylon, polyethylene and other thermoplastic elastomers. For example, theouter polymeric layer50 may be made of Pebax®, a polyether block amide made by Arkema, Inc. Pebax® of various durometers may be used, including, without limitation, Pebax 20D to Pebax 72D. Theouter polymeric layer50 may also comprise more than one layer or segment, including for example two or more tubes of a melt processing polymer arranged to abut one another and/or to overlap one another.
• Optionally, abraided layer40 may be placed over theinner polymeric layer20 before theouter polymeric layer50 is applied. Thebraided layer40 may be formed of stainless steel wire, including, for example, 0.003″ high tensile stainless steel wire. Thebraided layer40 may also be formed of a metal alloy, for example, a copper alloy. Thebraided layer40 may be formed in a standard braid pattern and density, for example, about 16 wires at about 45 to about 60 picks per inch (“PPI”) density. Alternatively, a braid may be used that is characterized by a varying braid density. For example, thebraided layer40 may be characterized by a first braid density at theproximal end16 of thecatheter12 and then transition to one or more different braid densities as thebraided layer40 approaches thedistal end14 of thecatheter12. The braid density at thedistal end14 may be greater or less than the braid density at theproximal end16. A catheter assembly having a braided layer with a varying braid density in described in U.S. patent publication no. 2007/0299424, which is incorporated herein by reference in its entirety. In a specific example, the braid density at the base (i.e., proximal end16) is about 50 PPI and the braid density atdistal end14 is about 10 PPI. In another embodiment, the braid density atdistal end14 is about 20% to about 35% of the braid density at the base/proximal end16.
• Thebraided layer40 may be formed separately on a disposable core. One or more portions of thebraided layer40 may be heat tempered and cooled before incorporation into thecatheter assembly12 by methods that are known to those of ordinary skill in the art. The action of heat tempering may help to release the stress on the wire and help reduce radial forces. Alternatively, thebraided layer40 may be braided directly about theinner layer20. A layer of heat shrink60 may optionally be placed over the top of theouter layer50. Theheat shrink layer60 may comprise a fluoropolymer or polyolefin material.
• FIG. 4 depicts thecatheter assembly12 after a lamination process. Thecatheter assembly12 may be laminated by heating the catheter assembly until the material comprising theouter layer50 flows and redistributes within thecatheter assembly12. Theheat shrink layer60 has a higher melting temperature than theouter layer50; therefore, during the melt process, theheat shrink layer60 retains its tubular shape and forces the liquefiedouter layer50 material to redistribute throughout braided layer40 (if present) and into the spaces betweenadjacent side lumens30 ofinner polymeric layer20. Thecatheter assembly12 may then be cooled. InFIG. 4, themandrel10 is still in place.
• Themandrel10 may be removed fromcatheter assembly12, leaving behind a lumen1I1 as illustrated inFIG. 5, which depicts acatheter12 made in accordance with the method of the present invention subsequent to the application of heat for the lamination process. If used, the small diameter mandrels (or set-up wires)90 may also be removed from theside lumens30.
• At least one elongate member70 may be inserted through theside lumens30. The elongate members70 may be used for a variety of purposes, for example to provide steerability or deflectability or to conduct energy to energy delivery elements, including, for example, electrodes, ultrasound transducers or microwave elements. The elongate members70 may comprise a wide range of materials, including, but not limited to, a metallic material, such as a metallic wire, alloy or clad material, a polymer material, including conductive polymers, a composite material, a fibrous material, such as high strength synthetic fibers made of high performance engineering polymer materials (e.g., Kevlar® fibers and the like), a resilient member, and a thread.
• As one example, a flat pull wire may be used in accordance with the present invention. The flat pull wire may be made of stainless steel and is may be from about 0.002-0.008 inches by about 0.006-0.024 inches, or larger. An example of a pull wire that is suitable for use with the present invention is described in U.S. patent publication no. 2007/0299424, which has been incorporated herein by reference in its entirety. A person of skill in the art will appreciate, however, that other types of pull wires may be used with the present invention, including, for example, pull wires having circular or oval cross sections and pull wires made of clad metals or metal alloys. In addition, the pull wire72 may also serve as the electrical wire74, or separate electrical wires may be used.
• Optionally, theheat shrink layer60 may be left in place around theouter layer50, as depicted inFIG. 5, even after themandrel10 is removed. If the heat shrink60 is removed, theouter layer50 becomes the outermost layer of thecatheter12. The result is a substantiallycircular catheter12 withmultiple side lumens30 integrally-formed withininner layer20, each side lumen containing at least one elongate member70.
• Catheter12 may further include one or more pull rings (not shown) to provide steerability. The pull wires are mechanically coupled to the one or more pull rings according to known methods.
• Another method of manufacturing thecatheter12 according to the present invention will be described with reference toFIGS. 6-9. In this embodiment, aninner polymeric layer120 and amulti-lumen layer130 are co-extruded.FIG. 6 depicts theinner polymeric layer120 after co-extrusion with themulti-lumen layer130. Theinner polymeric layer120 includes aninner surface102 defining amain lumen110 and anouter surface104. Themulti-lumen layer130 includes two ormore side walls132 and eachside wall132 defines aside lumen134. In one embodiment, theside walls132 are spaced about theouter surface104 of theinner polymeric layer120. In an alternate embodiment, theside walls132 are spaced about theinner surface102 of theinner polymeric layer120. Theside walls132 may be spaced symmetrically about theouter surface104 of theinner polymeric layer120, but need not be in a symmetrical orientation.
• The features of theside lumens30 described above with reference toFIGS. 2A-2D, including the number, dimensions, shapes and orientation of the side lumens about theouter surface15 of themain lumen11 apply equally to theside lumens134 comprisingmulti-lumen layer130. Thus, the number, dimensions, shapes and orientation of theside lumens134 in the multi-lumen layer can be selected by a person of ordinary skill to accommodate multiple elongate members of various sizes and cross-sectional configurations.
• Theinner polymeric layer120 and themulti-lumen layer130 may be made of the same or different materials. In one embodiment, theinner polymeric layer120 and themulti-lumen layer130 are extruded polytetrafluoroethylene (PTFE) tubing, such as Teflon® brand tubing, which is available commercially. Theinner polymeric layer120 may optionally be chemically etched to provide better adhesion during melt processing. As a person of skill in the art will appreciate, theinner polymeric layer120 may be made of other melt processable polymers. In one aspect, theinner polymeric layer120 is made of a material with a melting temperature higher than that of anouter layer160, which will be further described below, such that theinner polymeric layer120 will withstand melt processing of theouter layer160.
• FIG. 7 displays a cross-section of a catheter assembly prior to melt-processing of the layers by heating. Theinner polymeric layer120 andmulti-lumen layer130 are co-extruded. The co-extruded layers are placed onmandrel10. A small diameter mandrel or set-up wire90 may be placed within theside lumens134 to maintain the integrity of the side lumens during processing. Alternatively, a pull wire (FIG. 9) may be inserted through one or more of theside lumens132 in lieu of asmall diameter mandrel90. In still other embodiments, theside lumens132 may be maintained during processing via the use of a pressurized fluid.
• Anouter polymeric layer160 is then placed over themulti-lumen layer130. Theouter polymeric layer160 may be made of either single or multiple sections of tubing that may be either butted together or overlapped with each other. In one aspect, theouter polymeric layer160 is made of a melt-processable polymer, such as polyether block amides, nylon, polyethylene and other thermoplastic elastomers. For example, theouter polymeric layer160 may be made of Pebax®, a polyether block amide made by Arkema, Inc. Pebax® of various durometers may be used, including, without limitation, Pebax 20D to Pebax 72D. Theouter polymeric layer160 may also comprise more than one layer or segment, including for example two or more tubes of a melt processing polymer arranged to abut one another and/or to overlap one another.
• Optionally, abraided layer150 may be placed over themulti-lumen layer130 before theouter polymeric layer160 is applied. Thebraided layer150 may have any of the characteristics described above with reference to the braided layer40 (FIG. 3). Thebraided layer150 may be formed separately on a disposable core. One or more portions of thebraided layer150 may be heat tempered and cooled before incorporation into the catheter assembly by methods that are known to those of ordinary skill in the art. The action of heat tempering may help to release the stress on the wire and help reduce radial forces. A layer of heat shrink170 may optionally be placed over the top of theouter layer160. Theheat shrink layer170 may comprise a fluoropolymer or polyolefin material.
• FIG. 8 depicts the catheter assembly after a lamination process. The catheter assembly may be laminated by heating the catheter assembly until the material comprising theouter layer160 flows and redistributes within the catheter assembly. Theheat shrink layer170 has a higher melting temperature than theouter layer160; therefore, during the melt process, theheat shrink layer170 retains its tubular shape and forces the liquefiedouter layer160 material to redistribute throughout braided layer150 (if present) and around theside lumens134 of themulti-lumen layer130. The catheter assembly may then be cooled. InFIG. 8, themandrel10 is still in place.
• Themandrel10 may be removed fromcatheter assembly12, leaving behind alumen110 as illustrated inFIG. 9, which depicts acatheter12 made in accordance with the method of the present invention subsequent to the application of heat for the lamination process. If used, the small diameter mandrels (or set-up wires)90 may also be removed from theside lumens134 and at least one elongate member122, such as a pull wire124 or electrical wire126, may be inserted through theside lumens134.
• Optionally, theheat shrink layer170 may be left in place around theouter layer160, as depicted inFIG. 9, even after themandrel10 is removed. If the heat shrink170 is removed, theouter layer160 becomes the outermost layer of thecatheter12. The result is a substantiallycircular catheter12 withmultiple side lumens134 co-extruded withinner polymeric layer120, each side lumen containing at least one elongate member122.
• Although multiple embodiments of this invention have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this invention. For example, person of skill in the art could modifyinner polymeric layer20 andmulti-lumen layer130 to accommodate numerous combinations of pull wires and electrical wires of various shapes and dimensions by modifying the number, size and orientation of theside lumens30,134 within these layers.
• All directional references (e.g., upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present invention, and do not create limitations, particularly as to the position, orientation, or use of the invention. Joinder references (e.g., attached, coupled, connected, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other.
• It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.

Claims (35)

1. A method of manufacturing a catheter assembly comprising the steps of:

extruding an inner polymeric layer, the inner polymeric layer defining a main lumen having an inner surface and an outer surface and further defining two or more side lumens spaced about the outer surface of the main lumen, wherein a size of the side lumens is less than about ⅕ a size of the main lumen;

forming an outer polymeric layer disposed about the inner polymeric layer; and

inserting at least one elongate member through each side lumen of the inner polymeric layer.

2. The method according toclaim 1, wherein the two or more side lumens are spaced symmetrically about the outer surface of the main lumen.

3. The method according toclaim 1, wherein the inner polymeric layer comprises about 2-16 side lumens.

4. The method according toclaim 1, wherein the inner polymeric layer comprises about 6-16 side lumens.

5. The method according toclaim 1, wherein a size of the side lumens is about ⅕ to about 1/16 a size of the main lumen.

6. The method according toclaim 1, wherein the inner polymeric layer comprises polytetrafluoroethylene.

7. The method according toclaim 1 further comprising a step of forming a braided layer between the inner polymeric layer and the outer polymeric layer.

8. The method according toclaim 7, further comprising heating the inner polymeric layer, the braided layer and the outer polymeric layer to bond the inner polymeric layer, the braided layer and the outer polymeric layer together.

9. The method according toclaim 1, wherein the elongate member comprises at least one of a pull wire and an electrical wire.

10. A catheter assembly comprising:

an inner extruded polymeric layer defining a main lumen having an inner surface and an outer surface and further defining two or more side lumens spaced about the outer surface of the main lumen, wherein a size of the side lumens is less than about ⅕ a size of the main lumen;

an outer polymeric layer disposed about the inner extruded polymeric layer; and

at least one elongate member extending through one of the side lumens.

11. The catheter assembly according toclaim 10, wherein the inner extruded polymeric layer comprises polytetrafluoroethylene.

12. The catheter assembly according toclaim 10, wherein the inner extruded polymeric layer comprises about 2-16 side lumens.

13. The catheter assembly according toclaim 10, wherein the inner extruded polymeric layer comprises about 6-16 side lumens.

14. The catheter assembly according toclaim 10, wherein a size of the side lumens is about ⅕ to about 1/16 a size of the main lumen.

15. The catheter assembly according toclaim 10, wherein the two or more side lumens are spaced symmetrically about the outer surface of the main lumen.

16. The catheter assembly according toclaim 10, wherein the at least one elongate member comprises at least one of a pull wire and an electrical wire.

17. The catheter assembly according toclaim 10, further comprising a braided layer disposed between the inner extruded polymeric layer and the outer polymeric layer.

18. A method of manufacturing a catheter assembly comprising the steps of:

co-extruding an inner polymeric layer and a multi-lumen layer, wherein the inner polymeric layer comprises an inner surface defining a main lumen and an outer surface, and wherein the multi-lumen layer comprises two or more side walls, each side wall defining a side lumen;

forming an outer polymeric layer about the multi-lumen layer; and

inserting at least one elongate member through each side lumen,

wherein a size of the side lumens is less than about ⅕ a size of the main lumen.

19. The method according toclaim 18, wherein the inner polymeric layer and the multi-lumen layer comprise the same material.

20. The method according toclaim 18, wherein the inner polymeric layer and the multi-lumen layer comprise polytetrafluoroethylene.

21. The method according toclaim 18, wherein the inner polymeric layer and the multi-lumen layer comprise different materials.

22. The method according toclaim 18, wherein the multi-lumen layer comprises about 2-16 side lumens.

23. The method according toclaim 18, wherein the multi-lumen layer comprises about 6-16 side lumens.

24. The method according toclaim 18, wherein a size of the side lumens is about ⅕ to about 1/16 a size of the main lumen.

25. The method according toclaim 18, wherein the side lumens are spaced symmetrically about the outer surface of the main lumen.

26. The method according toclaim 18 further comprising a step of forming a braided layer between the multi-lumen layer and the outer polymeric layer.

27. The method according toclaim 26 further comprising heating the inner polymeric layer, the multi-lumen layer, the braided layer and the outer polymeric layer to bond the inner polymeric layer, the multi-lumen layer, the braided layer and the outer polymeric layer together.

28. The method according toclaim 18, wherein the at least one elongate member comprises at least one of a pull wire and an electrical wire.

29. A catheter assembly comprising:

an inner polymeric layer having an inner surface defining a main lumen and an outer surface;

a multi-lumen layer disposed about the outer surface of the inner polymeric layer, the multi-lumen layer comprising two or more side walls, each side wall defining a side lumen, wherein the multi-lumen layer and the inner polymeric layer are co-extruded,

an outer polymeric layer disposed about the multi-lumen layer; and

at least one elongate member extending through one of the side lumens,

wherein a size of the side lumens is less than about ⅕ a size of the main lumen.

30. The catheter assembly according toclaim 29, wherein the side lumens are spaced symmetrically about the outer surface of the main lumen.

31. The catheter assembly according toclaim 29, wherein the multi-lumen layer comprises about 2-16 side lumens.

32. The catheter assembly according toclaim 29, wherein the multi-lumen layer comprises about 8-16 side lumens.

33. The catheter assembly according toclaim 29, wherein a size of the side lumens is about ⅕ to about 1/16 a size of the main lumen.

34. The catheter assembly according toclaim 29, wherein the at least one elongate member comprises at least one of a pull wire and an electrical wire.

35. The catheter assembly according toclaim 29, further comprising a braided layer disposed between the multi-lumen layer and the outer polymeric layer.

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