Abstract: A catheter includes a proximal shaft, a distal shaft including a proximal end portion having an inner cavity into which a distal end portion of the proximal shaft is fitted, and a core wire extending through the inner cavity of the distal shaft. The core wire has a proximal end portion that is joined to a cutout portion formed in the distal end portion of the proximal shaft. Joining means are formed along a joint surface between the proximal end portion of the core wire and the cutout portion. When the joining means are divided into first joining means and second joining means along a longitudinal axis of the catheter, a length of one of the first joining means and the second joining means is larger than a length of the other of the first joining means and the second joining means.

Abstract: A device and method for preventing an occlusion of a catheter including a catheter adapter and a catheter where a flexured portion of the catheter is supported by a bending surface of the catheter adapter. The flexured portion of the catheter may also include a maximum insertion length mark and/or a flexible support member to support and strengthen the flexured portion of the catheter against occlusions. A bending surface is provided over which a flexured portion of the catheter may gently bend to accommodate the transition of the catheter from the catheter adapter to the insertion site without occluding the catheter.

Abstract: A catheter having a distal tip comprising two sections of different hardness, and a method of making the same, is herein disclosed. The first section of the two sections is distal to the second section of the two sections and the second section is comprised of a material that is harder than the material of the first section. Additionally, the distal tip is bonded to a catheter shaft and the material of the catheter shaft is harder than the material of the first and second sections. The material of the catheter shaft, first section, and second section can comprise polyether block amide, with each section and the catheter shaft having different properties.

Abstract: Microcannulae are constructed with multiple components in a composite design, allowing the microcannulae to have varying mechanical and delivery properties that will enable ophthalmic treatments by minimally invasive means. The microcannula includes at least one flexible, tubular communicating element with an outer diameter of 350 microns or less, a proximal connector for introduction of materials, energy or tools. It may also include a reinforcing member attached to the communicating element, which may be designed to create variable stiffness along the length of the microcannula. The microcannula may also include other features such as a signal beacon near the distal tip.

Abstract: An introducer sheath and a method for making the sheath. The sheath includes a fluoropolymer liner having a passageway extending longitudinally therethrough. An inner jacket is positioned longitudinally over the liner, and the inner surface of the inner jacket is bonded to the outer surface of the liner. An outer jacket is positioned longitudinally over the inner jacket, and the inner surface of the outer jacket is bonded to the outer surface of the inner jacket. A reinforcing coil is encapsulated within the inner jacket and the outer jacket.

Abstract: A catheter assembly comprises a first catheter including a wall with an inner surface at least partially defining a lumen. A second catheter is connected to the wall of the first catheter and is disposed outward of the inner surface of the wall. The second catheter is at least partially covered by a sheath portion of the first catheter. A first portion of the wall of the first catheter is made of a relatively low durometer elastomeric material and is relatively extensible. A second portion of the wall is formed of a relatively high durometer elastomeric material and is relatively inextensible.

Abstract: Catheter assembly including an elongate shaft comprising a thermoplastic polymer such as a thermoplastic shape memory polymer having a pre-selected glass transition temperature (Tg) and a means for heating the thermoplastic polymer, wherein the thermoplastic polymer is in a rubbery state at temperatures above the glass transition temperature and is in a glassy state at temperatures below the glass transition temperature. The elongate shaft may be selectively heated and cooled to provide sufficient flexibility and retention during a medical procedure.

Abstract: A catheter includes an outer tube, and an inner tube which is disposed inside the outer tube and through which a guide wire is passed via a distal-side opening and a proximal-side opening. The outer tube has, in the axial direction thereof, at least: a first region on the distal side; a second region disposed on the proximal side and higher in rigidity than the first region; and a transition region which is provided between the first region and the second region and of which rigidity varies from the same rigidity as that of the first rigidity to the same rigidity as that of the second rigidity. The outer tube is configured with an opening, to which the proximal-side opening of the inner tube is connected, being provided in the second region.

Abstract: A catheter assembly for cannulating an ostium of a coronary sinus of a heart comprises an outer catheter member and an inner catheter member. The outer catheter member has a distal end portion including a deflectable distal end and a lumen extending through the deflectable distal end, wherein the distal end portion includes regions of varying stiffness and has a pre-formed curvature. The inner catheter member is slidably and rotatably disposed within the lumen of the outer catheter member, and has a distal end portion including a distal end, and a lumen extending through the distal end. The distal end portion of the inner catheter member has regions of varying stiffness and a pre-formed curvature. The outer and inner catheter members are configured such that relative translation and rotation of the outer and inner catheter members causes the distal end of the outer catheter member to assume a plurality of two and three dimensional shapes.

Abstract: Methods and devices for perfusing a blood vessel during the entire course of an end-to-side or end-to-end anastomosis procedure. One method can be used to form an end-to-side anastomosis of a saphenous vein graft to a coronary artery during an off-pump, beating heart, coronary artery bypass graft. In this example, the distal end of an elongate tube carrying a saphenous vein graft is advanced into an arteriotomy distal to an occlusion in the coronary artery. Perfusing blood flow is provided through the tube to the coronary artery, the vein graft is advanced over the tube to the arteriotomy and sutured completely to the coronary artery. The elongate tube can be retracted through the now secured vein graft, and the coronary artery supplied again from the proximal end of the vein graft. Some tubular devices include a reversibly expandable distal region, to form a seal between the inserted tube and the coronary artery being perfused, to prevent blood flow into the surgical field.

Abstract: The present application relates to method of arresting telescopic endwise relative movement in a medical device between an end portion of an elongate member, preferably being a cylinder, and an end portion of a tube, preferably being a cylindrical tube, that receives the end portion of the elongate member. The method is of particular use in the construction of stent delivery systems. In one embodiment, the method comprises providing a length of deformable blocking material; imparting relative endwise movement to draw the blocking material, into the gap and reversing the direction until the blocking material length suffers deformation.

Abstract: A medical catheter including a composite laminated shaft having a longitudinal segment that is mechanically deformed to have reduced and varying stiffness. A method of making the catheter is also disclosed.

Abstract: Medical devices such as catheters can include structure or provision that permit a physician or other health care professional to adjust the stiffness of at least a portion of the medical device. In some instances, the medical device may be adjusted prior to inserting the medical device into a patient. In some cases, the medical device may be adjusted while in use within the patient.

Abstract: A catheter having a selectively variable degree of flexibility includes an elongate tubular outer member and an elongate tubular inner member disposed within the outer member. The catheter further includes a cavity disposed in between the outer and inner members. A tubular braid of filaments may be disposed within the cavity. The outer and inner members are movable relative to each other along intermediate portions thereof when in a first configuration, and are not movable relative to each other when in a second configuration. When the inner and outer members are in the first configuration, the tubular braid of filaments is movably disposed relative to at least one of the outer member and the inner member. When the inner and outer members are in the second configuration, the inner and outer members clamp the tubular braid of filaments in a fixed position relative to the inner and outer members.

Abstract: Catheters for aspiration of thrombotic, atherosclerotic or other particulate embolic debris from a blood vessel. An elongate flexible aspiration tube has an aspiration lumen defined by a reinforced tube wall. A guidewire tube is secured alongside the aspiration tube extending proximally from a distal end thereof to define either over-the-wire or single operator catheter configurations. The portion of the aspiration tube alongside the guidewire tube has an oval transverse cross section with a minor axis extending transversely through the guidewire tube. The oval cross section of the aspiration tube improves the catheter's efficient use of cross sectional space by making the overall catheter transverse cross section nearly equal in orthogonal dimensions. Methods of making aspiration catheters are also disclosed, including permanently deforming the portion of the aspiration tube into an oval transverse cross section.

Abstract: A coaxial guide catheter to be passed through guide catheter having a first lumen, for use with interventional cardiology devices that are insertable into a branch artery that branches off from a main artery. The coaxial guide catheter is extended through the lumen of the guide catheter and beyond the distal end of the guide catheter and inserted into the branch artery. The device assists in resisting axial and shear forces exerted by an interventional cardiology device passed through the second lumen and beyond the flexible distal tip portion that would otherwise tend to dislodge the guide catheter from the branch artery.

Abstract: A noncircular inner lumen guiding catheter with assisted variable support has an inner wall defining a noncircular cross-sectional shaped lumen for use in delivery of multiple microcatheters or other devices for treatment of neurovascular defects, such as for treatment of aneurysms. The noncircular inner lumen guiding catheter with assisted variable support includes torque transmittal guidance walls that are flexible linearly but not circumferentially, and that are neither collapsible nor kinkable. The noncircular shaped cross-section of the inner lumen may extend along the entire length of the catheter or a portion thereof, including distal or proximal.

Abstract: A system for arterial access for delivery of treatment devices is provided. In one embodiment, the system comprises a guidewire and a catheter. The catheter comprises a handle and a shaft. The shaft may be a steerable/deflectable tip shaft with a lumen adapted to allow passage of the guidewire at least partially there through. A passive sheath may also be provided to be delivered over the shaft. The handle controls the steerable/deflectable tip shaft and may be used to deflect the distal tip of the shaft.

Abstract: An apparatus having an elongate hollow metal body extending along a longitudinal axis is disclosed. The hollow body defines a central opening and has a predetermined wall thickness. A pattern of laser cut slits is formed into the body. The slits define a plurality of articulatable elements. The plurality of articulatable elements enable active articulation of the body in a first plane and passive deflection in planes orthogonal to the first plane.

Abstract: A deflectable catheter comprises a catheter body, a tip section, and a control handle for affecting deflection of the tip section. The tip section comprises a flexible tubing having proximal and distal ends and at least two lumens extending therethrough. The proximal end of the tip section is fixedly attached to the distal end of the catheter body. The flexible tubing comprises a plastic core, a metal braid over the core, a plastic skin over the braid, and at least two pieces of plastic tubing in longitudinal arrangement extruded over the plastic skin, wherein the at least two pieces of plastic tubing have different stiffnesses and are arranged with the stiffer plastic being proximal the less stiff plastic. The tip section is made by extruding a plastic core over at least one mandrel and braiding a metal over the plastic core.

Abstract: A catheter steering mechanism includes a tubular member defining a passage. The tubular member has a longitudinally extending cutaway portion defining a bend-enhancing region formed at a predetermined location along a length of the tubular member. An actuator is received in the passage of the tubular member, a distal part of the actuator being fast with a distal part of the tubular member. A restraining arrangement is defined by the tubular member, the restraining arrangement comprising a structure arranged at the bend-enhancing region to retain the actuator substantially within the confines of the tubular member during bending.

Abstract: A treatment tool insertion channel of an endoscope, which is arranged through an inside of an insertion part that includes a flexible tube and a bendable part, includes a flexible inner tube, a spiral groove formed around the flexible inner tube over an entire length of the bendable part and the flexible tube, at least one coil wound along a bottom of the spiral groove, and at least one type of filler with which the spiral groove is filled. The treatment tool insertion channel includes a first portion that includes a part inside the bendable part and a second portion at a proximal end side of the first portion, the first portion being configured more flexible than the second portion.

Abstract: Devices and methods for transferring forces down a catheter shaft while also maintaining an open fluid pathway are disclosed. In some of the designs, inner and outer members of the catheter interact, allowing improved transfer of forces down the catheter shaft. These designs also allow for maintenance of a fluid pathway along the length of the shaft, including at locations where the inner and outer members are interacting with one another. Structures are disclosed which extend at least a portion of the length of the shaft, allowing improved force transfer and resistance to kinking. Structures are also disclosed which specifically allow for inner and outer members to engage one another at at least one point along the shaft, improving the transfer of forces down the shaft.

Abstract: A ureteral access sheath having nonuniform axial-stiffness adapted for proximal pushability needed for placement while also having distal flexibility to minimize trauma to the body lumen and ureter. Embodiments in accordance with the present invention provide a nonuniform axial-stiffness ureteral access sheath comprising a nonuniform axial-stiffness jacket encapsulating the reinforcement layer with the inner liner. Other embodiments in accordance with the present invention provide a nonuniform axial-stiffness ureteral access sheath comprising a nonuniform axial-stiffness reinforcement layer encapsulated between a single axial-stiffness jacket and the inner liner. Other embodiments in accordance with the present invention provide a nonuniform axial-stiffness ureteral access sheath comprising a nonuniform axial-stiffness jacket encapsulating a nonuniform axial-stiffness reinforcement layer with the inner liner.

Abstract: A vessel tracking device for use with a pressure source has an elongate introduction element configured for introduction into a vessel of a human body, the introduction element having a proximal end and a distal end, and the distal end having a flexible distal end portion containing an internal cavity that is closed at the distal end. A pressure adjuster is configured for communication with said pressure source. The introduction element has a connection channel connected to the pressure adjuster at the proximal end of the introduction element, the connection channel being connected with the internal cavity and placing the internal cavity in communication with the pressure source, with the pressure adjuster controlling an internal pressure in the internal cavity. The distal end portion has different wall portions that are differently deformed as the internal pressure is adjusted, to produce a change in direction of the distal end controlled by the pressure controller.

Abstract: According to one aspect, an interventional medical device includes a first wire disposed at a distal end and made of an alloy containing Ti and a transition metal other than Ti and Cr, and a second wire disposed at a proximal end of the first wire and made of an alloy containing Cr and a transition metal other than Cr and Ti. The device may include the first wire and the second wire being brazed to each other by a brazing material. The brazing material contains a metal whose ionization tendency is more basic than Ti and Cr. The brazing material is preferably an Ag—Mg alloy or an Ni—Mg alloy, and preferably has a composition near the eutectic point.

Abstract: A dual braided catheter shaft includes a flat wire forming the inner braid, thereby potentially allowing for reduced radial thickness of the shaft. In one embodiment, the shaft (100) includes an inner polymer jacket (104), an inner braid (106) formed on the inner jacket (104), an intermediate jacket (108) formed over the inner braid (106), an outer braid (110) formed on the intermediate jacket (108) and an outer jacket (112) formed on the outer braid (110). A preferred construction process involves extruding polymer material directly onto each of the inner and outer braids (106 and 110) so that little or no air gaps remain between the polymer material and the braids (106 and 110). The braiding parameters of the inner and outer braids (106 and 110) can be varied along the length of the catheter to provide varying mechanical properties.

Abstract: The present invention provides devices and methods for attachment of an endolumenal gastrointestinal device, such as an artificial stoma device, a gastrointestinal bypass sleeve or other therapeutic or diagnostic device, within a patient's digestive tract. In one application of the invention, an endolumenal bypass sleeve is removably attached in the vicinity of the gastroesophageal junction to treat obesity and/or its comorbidities, such as diabetes. The bypass sleeve may be at least partially deployed by eversion.

Abstract: A catheter which allows the rotational orientation of the distal end of the catheter to be adjusted in discrete intervals as the physician rotates the proximal end of the catheter. The catheter is designed to intentionally induce whipping but to limit the amount of whipping to a desired rotational interval.

Abstract: Microcannulae are constructed with multiple components in a composite design, allowing the microcannulae to have varying mechanical and delivery properties that will enable ophthalmic treatments by minimally invasive means. The microcannula includes at least one flexible, tubular communicating element with an outer diameter of 350 microns or less, a proximal connector for introduction of materials, energy or tools. It may also include a reinforcing member attached to the communicating element, which may be designed to create variable stiffness along the length of the microcannula. The microcannula may also include other features such as a signal beacon near the distal tip.

Abstract: A method of non-delaminably bonding a non-porous thermoplastic elastomer to a substrate by heating a bilayer of the elastomer and the substrate for a predetermined time and a product obtained by the method. Methods for producing non-delaminable conduits and non-delaminable kink-resistant conduits constructed of biocompatible elastomers and substrates, and products produced by these methods are taught. Methods, products, and articles of manufacture relating to non-delaminable monofilament supported kink-resistive conduits that may be used as inflow conduits in left ventricular assist devices for treatment of heart failure are also provided.

Abstract: A coaxial guide catheter to be passed through guide catheter having a first lumen, for use with interventional cardiology devices that are insertable into a branch artery that branches off from a main artery. The coaxial guide catheter is extended through the lumen of the guide catheter and beyond the distal end of the guide catheter and inserted into the branch artery. The device assists in resisting axial and shear forces exerted by an interventional cardiology device passed through the second lumen and beyond the flexible distal tip portion that would otherwise tend to dislodge the guide catheter from the branch artery.

Abstract: A catheter includes an elongate member having a braided reinforcing layer. The reinforcing layer comprises a plurality of continuous filaments that transform from a braided configuration to short axially oriented segments in a least one location along the catheter. Also disclosed is a method of manufacturing a braided elongate member including providing a core, forming at least one braided portion with a plurality of filaments and forming at least one short axially oriented segment with at least a portion of the same plurality of filaments.

Abstract: A medical device, such as a medical guidewire, having a portion including an inner zone of material and an outer peripheral zone of material surrounding the inner zone of material. The inner zone of material has a first coefficient of thermal expansion and the outer peripheral zone of material has a second coefficient of thermal expansion less than the first coefficient of thermal expansion, wherein at an operating temperature the outer peripheral zone of material opposes expansion of the inner zone of material such that the outer peripheral zone of material exerts a compressive stress on the inner zone of material.

Abstract: A catheter assembly comprises an outer catheter including an outer catheter body and an outer catheter hub at a proximal portion of the outer catheter body; and an inner catheter including an inner catheter body insertable in the outer catheter body, a tip at the distal portion of the inner catheter body which is rich in flexibility, and an inner catheter hub at the proximal portion of the inner catheter body adapted to be coupled to the outer catheter hub. The inner catheter body includes a flexible section connected the tip, a physical property transition section on the proximal side of the flexible section, a first body section on the proximal side of the physical property transition section, a second body section on the proximal side of the first body section, greater than the first body section in flexural rigidity, and having a reinforcing material layer.

Abstract: A deflectable catheter assembly and methods of use are herein disclosed. The catheter assembly, in one embodiment, is deflectable and includes a first catheter, a second catheter, and a third catheter. The second catheter fits coaxially within the first catheter. In some embodiments, the first and/or second catheter can be constituently different from proximal end to distal end. At least one of the first catheter and the second catheter include a deflectable portion to allow deflection of that catheter from a first position to a second position. The third catheter has a sheath and a medical instrument positioned within the sheath. The third catheter fits coaxially within the second catheter.

Abstract: Delivery system for delivery of a medical device includes an inner member having a proximal section, a distal section and a longitudinal axis therebetween. The inner member has a first layer and a second layer wherein the first layer and the second layer are attached together at a first segment and a second segment. The second segment is spaced from the first segment along a length of the inner member and the first layer and the second layer are free of attachment between the first segment and the second segment. The inner member further includes at least two wires disposed along the length of the inner member between the first layer and the second layer. As disclosed, the at least two wires can include a first coil and a second coil moveable relative to each other between the first and second segments.

Abstract: An elongate medical device such as a guidewire, that may comprise a first elongate member having a proximal end, a distal end and a lumen there between, a second elongate member having a proximal end and a distal end, the second elongate member at least partially disposed in the first elongate member, a first connection between first elongate member and the second elongate member at the proximal end of the first elongate member, a second connection between the first elongate member and the second elongate member at the distal end of the first elongate member, and a third connection between the first elongate member and the second elongate member, the third connection disposed at a point between the first connection and the second connection, wherein the third connection is substantially at a location selected by the Method for Enhancing the Ratio of Torsional Stiffness to Transverse Flexibility.

Abstract: Described herein are devices and methods for guide catheters having one or more regions of increased flexibility. A flexibility region comprises one tubular segment of the guide catheter with a non-linear longitudinal seam between two non-concentric layers of material having different durometers. A non-linear seam, such as a zig-zag or sinusoidal configuration, permits controlled compression of lower durometer material between portions of higher durometer material.

Abstract: An articulation segment for a catheter includes a tube formed with a first plurality of axially aligned slits that are respectively oriented in planes perpendicular to the axis, with each slit extending azimuthally in an arc partway around the axis. The tube is also formed with a second plurality of similarly formed slits that are axially offset and diametrically opposed relative to the slits of the first plurality to allow for a bending of the catheter in a plurality of different planes. In a particular embodiment, the slits are arranged to allow the articulation segment to be reconfigured from a straight, substantially cylindrically shaped tube to a configuration in which a portion of the articulation segment is formed in the shape of a ring.

Abstract: A catheter enabling an increase in operability when the catheter is inserted from the outside to the inside of a body and capable of remarkably reducing the risk of damage to shafts even in an unforeseen accident without complicating steps and increasing production cost. The catheter comprises at least the distal side shaft formed of a resin tube, the rear end side shaft with a higher rigidity than that of the distal side shaft, and a guide wire lumen. The catheter is characterized in that a core wire is disposed therein to adjust a flexibility so that the rear end portion of the distal side shaft is harder than the distal end portion of the distal side shaft and softer than the rear end side shaft, and the core wire is fixed to the distal side shaft near the rear end side opening part of the guide wire lumen and at a part of the rear end side portion of the distal end shaft.

Abstract: Medical devices such as catheters can include structure or provision that permit a physician or other health care professional to adjust the stiffness of at least a portion of the medical device. In some instances, the medical device may be adjusted prior to inserting the medical device into a patient. In some cases, the medical device may be adjusted while in use within the patient.

Abstract: The catheter comprises a catheter tube formed of two superposed tubular layers of materials which differ from one another. A tubular mediator layer is arranged between the layers to provide an adhesive anchorage for the layers.

Abstract: Ureteral access sheaths can have a nonuniform axial-stiffness. A nonuniform axial-stiffness ureteral access sheath can have an inner liner defining a longitudinally extending and generally uniform bore. A non-uniform axial-stiffness outer jacket can define a longitudinally tapered outer surface, and a reinforcement layer can be encapsulated between the inner liner and the non-uniform axial-stiffness outer jacket. The reinforcement layer can have a non-uniform axial-stiffness. For example, a proximal portion of the reinforcement layer can be thicker than a distal portion of the reinforcement layer. A coil of wire can be included in the reinforcement layer, and a diameter of the wire in a proximal portion of the reinforcement layer can be larger than a diameter of the wire in a distal portion of the reinforcement layer. In some instances, the diameter of the wire tapers from the proximal portion to the distal portion.

Abstract: A catheter assembly including at least one introducer defining a passage receiving an elongate tubular member having a proximal end, a distal end, and a lumen extending between an elongate shape-imparting element received in the lumen and imparting a predetermined shape to the distal end of the elongate tubular member, when the distal end of the elongate tubular member is extended beyond a distal end of the at least one introducer. A distal end of the one-piece shape-imparting element extends from the lumen of the elongate tubular member and is anchored proximal the distal end of the at least one introducer.

Abstract: An elongate shaft of a medical catheter including a thermoset polymeric tubular member including a skived distal portion. The skived distal portion includes a distally extending trough having a convex surface and a concave surface. A thermoplastic tubular sleeve may be positioned over at least a portion of the skived distal portion of the thermoset polymeric tubular member. In some instances, the thermoplastic tubular sleeve includes a crescent-shaped tubular portion defining a crescent-shaped lumen. The trough of the skived distal portion may extend through the crescent-shaped lumen. The thermoplastic tubular sleeve is thermally bonded to the inner and outer tubular members of a distal section of the elongate shaft at a guidewire port joint.

Abstract: A method for making a deflectable catheter includes positioning a flexible element along a catheter liner. A flexible element distal portion extends along at least a portion of a deflectable distal end portion of the catheter liner. At least one anchor is engaged to the flexible element distal portion. The anchor extends at least part way around the flexible element distal portion. An encapsulant is positioned around at least the flexible element distal portion and the deflectable distal end portion.

Abstract: A coaxial guide catheter to be passed through guide catheter having a first lumen, for use with interventional cardiology devices that are insertable into a branch artery that branches off from a main artery. The coaxial guide catheter is extended through the lumen of the guide catheter and beyond the distal end of the guide catheter and inserted into the branch artery. The device assists in resisting axial and shear forces exerted by an interventional cardiology device passed through the second lumen and beyond the flexible distal tip portion that would otherwise tend to dislodge the guide catheter from the branch artery.

Abstract: A catheter includes a proximal shaft having a relatively high rigidity, a distal shaft provided on a front portion of the proximal shaft so as to be in fluid communication with proximal shaft and having a rigidity lower than that of the proximal shaft, a hub mounted to the vicinity of a rear end of the proximal shaft and configured to allow a pressure applying apparatus to be mounted to the hub, and a balloon provided on a front portion of the distal shaft so as to be in fluid communication with the distal shaft and configured to receive pressure applied from the hub. The catheter also includes a guide wire lumen. In this catheter, at least a front portion of the distal shaft is configured as a grooved portion having a groove or grooves.

Abstract: A medical device including a sheath having an inner liner and an outer layer attachable to a coil independent from each other to allow the inner liner and the outer layer the freedom to move coaxially independent from each other. The coil can be closely wound at a predetermined coil spacing sufficient to inhibit portions of the outer layer from entering into voids between the adjacent coil windings. Intermediate layers for bonding between the coil and the inner liner and/or the outer layer may also be provided. A filler material can be disposed within the voids between the adjacent windings of the coil. The filler material has a dimension sized to bridge the void between adjacent coil windings in order to inhibit portions of the outer layer from bonding to the inner liner. The filler material can be in the form of a ribbon.