US 8123994 B2
Methods and devices incorporating a guidewire entry port subassembly for use in rapid exchange catheters. The use of a subassembly allows for stronger quality control and simpler fabrication of a rapid exchange device. In several embodiments, methods of making a molded guidewire entry port using a mold, often in conjunction with one or more mandrels, are disclosed. Several device embodiments include a separate molded guidewire port as well as molded guidewire ports which are attached, during a molding step, to segments of a catheter.
1. A method of making a catheter, the method comprising:
forming a port joint having a proximal end and a distal end, the port joint including an inflation lumen extending from the proximal end to the distal end of the port joint, the port joint including a guidewire lumen extending from the distal end to a guidewire port located intermediate the proximal end and the distal end of the port joint, the guidewire lumen of the port joint defined by an interior surface of the port joint fully surrounding a periphery of the guidewire lumen;
joining a proximal shaft section of the catheter to the proximal end of the port joint such that a lumen of the proximal shaft section is in fluid communication with the inflation lumen of the port joint; and
joining a distal shaft section of the catheter to the distal end of the port joint such that a first lumen of the distal shaft section is in fluid communication with the inflation lumen of the port joint and a second lumen of the distal shaft section is in fluid communication with the guidewire lumen of the port joint;
wherein the port joint is formed of a material discrete from materials forming the proximal shaft section and the distal shaft section.
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11. A method of making a catheter, the method comprising:
providing a proximal tubular member of a catheter shaft, the proximal tubular member having a proximal end, a distal end, and a lumen extending therethrough;
providing a first distal tubular member of the catheter shaft, the first distal tubular member having a proximal end, a distal end, and a lumen extending therethrough;
providing a second distal tubular member of the catheter shaft, the second distal tubular member having a proximal end, a distal end, and a lumen extending therethrough,
wherein both of the first and second distal tubular members are structurally distinct from the proximal tubular member;
providing a port joint for coupling the proximal tubular member of the catheter shaft to the first and second distal tubular members of the catheter shaft, the port joint adapted to couple the lumen of the proximal tubular member to the lumen of the first distal tubular member;
the port joint including:
a) a guidewire lumen disposed within the port joint for directing a guidewire into the lumen of the second distal tubular member, the guidewire lumen defined by an interior surface of the port joint fully surrounding a periphery of the guidewire lumen; and
b) a guidewire port for receiving a guidewire through an exterior wall of the port joint into the guidewire lumen, the guidewire port located intermediate a proximal end and a distal end of the port joint;
attaching the port joint to the distal end of the proximal tubular member of the catheter shaft; and
attaching the port joint to the proximal ends of the first and second distal tubular members of the catheter shaft.
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16. A method of making a catheter shaft, the method comprising:
providing a port joint for coupling a proximal member of a catheter shaft to one or more distal members of the catheter shaft that are structurally distinct from the proximal member, the port joint adapted to couple a lumen in the proximal member to a first lumen defined by the distal member(s);
the port joint including:
a) a guidewire lumen disposed within the port joint for directing a guidewire into a second lumen defined by the distal member(s), the guidewire lumen defined by an interior surface of the port joint fully surrounding a periphery of the guidewire lumen; and
b) a guidewire port for receiving a guidewire through an exterior wall of the port joint into the guidewire lumen, the guidewire port located intermediate a proximal end and a distal end of the port joint;
attaching the port joint to a distal end of the proximal member of the catheter shaft; and
attaching the port joint to a proximal end of the one or more distal members of the catheter shaft;
wherein the distal end of the proximal member of the catheter shaft is proximal of the proximal end of the one or more distal members of the catheter shaft, and the distal end of the proximal member of the catheter shaft is longitudinally separated from the proximal end of the one or more distal members of the catheter shaft by the port joint;
wherein the formed catheter shaft includes the proximal member, the port joint, and the one or more distal members.
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This application is a continuation of co-pending U.S. application Ser. No. 10/653,375, filed Sep. 2, 2003, the entire disclosure of which is incorporated herein by reference.
The present invention is related to medical devices, more particularly to elongate medical devices such as catheters. In particular, the present invention is related to catheters which have a distal guidewire port.
Single-operator-exchange (SOE) or “monorail” catheters are catheters in which only a distal portion of the catheter tracks over a guidewire. Proximal of the distal portion that tracks the guidewire, an SOE catheter and guidewire are separate from one another. This allows the proximal portion of the SOE catheter to be relatively simple, having need of one less lumen than would be required for an over-the-wire catheter that tracks a guidewire over its entire length. An SOE catheter is also useful because, by not tracking the guidewire over its entire length, the catheter and guidewire are more easily moved relative one another, such as during a catheter exchange. One example of an early patent in this area is U.S. Pat. No. 5,156,594 to Keith, the disclosure of which is incorporated by reference.
A drawback for SOE catheters is the difficulty of fabrication. Construction of an SOE device typically involves welding or fusing several lengths of tubing together such that a distal portion of the SOE device includes an additional lumen for receiving a guidewire. A guidewire opening or port is provided to allow a guidewire to be introduced to the guidewire lumen through the guidewire port. A number of different manners for providing the guidewire port joint to a rapid exchange-type of medical device have been suggested, for example, by Fitzmaurice et al., U.S. Pat. No. 6,190,358; Enger, U.S. Pat. No. 5,980,486; Estrada et al., U.S. Pat. No. 6,344,029, and Williams et al., U.S. Pat. No. 6,409,863. Williams et al. is also hereby incorporated by reference. The disclosure of the Keith patent above, incorporated by reference, discloses a crimped hypotube which is then attached to a distal polymer member having a guidewire tube and an outer tube around the guidewire tube.
The steps of preparing (including, for example, crimping, trimming or cutting), placing and fusing the tubular members in proper alignment are labor intensive, creating costs in terms of labor, time and quality assurance. This is particularly so given the small size of the various pieces of the final SOE product.
The present invention provides a number of methods for providing guidewire port subassembly for use in a catheter, as well as a number of pieces for using in assembling a catheter. A number of combinations are provided in a number of embodiments, where none or one or more of the proximal, distal guidewire or distal outer tubular members may be fused to the port subassembly during fabrication of the port subassembly.
A first embodiment includes a method of making a catheter comprising providing a port joint for coupling a proximal member to one or more distal members, the port joint adapted to couple a lumen in the proximal member to a lumen defined by the distal member(s). For the illustrative method, port joint includes a guidewire port for receiving a guidewire and a guidewire lumen for coupling the guidewire into a lumen defined by said distal member(s).
In several embodiments, a method of providing a port joint subassembly for a rapid exchange catheter is provided. The method includes molding a port joint subassembly for joining a proximal member having a first lumen to a distal member having a second lumen and a distal guide member having a guidewire lumen, the port joint subassembly adapted to couple the first lumen to the second lumen and including a guidewire port for directing a guidewire from outside the catheter into the guidewire lumen. In several illustrative embodiments, the port joint subassembly may be attached to one or more of the proximal member, the distal member or the distal guide member during fabrication. The attachment may be accomplished by providing a portion of one or more of the proximal member, the distal member or the distal guide members inside a mold used to shape the port joint subassembly in an injection molding process. In further embodiments, the port joint subassembly may be provided with structures adapted to receive or attach to the proximal member, the distal member or the distal guide member.
One embodiment comprises a port joint subassembly adapted to couple to a proximal member and two distal members. Several embodiments encompass devices including molded port joint subassemblies. In one such embodiment, the device includes a proximal member for providing an inflation fluid which is attached to a port joint subassembly by molding the port joint with over the proximal member to create an attachment between the two. The proximal member may be inserted to a mold for shaping the port joint subassembly and some portion of the port joint subassembly molded around the proximal member. The proximal member may also be inserted to a mold for shaping the port joint subassembly and some portion of the port joint subassembly allowed to flow into the proximal member to create attachment from the interior of the proximal member. A combination of inner and outer attachment may also be provided as desired. Additional embodiments include provision of a distal guide member and distal member in like fashion as that just explained with respect to the proximal member.
Further embodiments include methods for providing strain relief across a port joint subassembly by molding the port joint subassembly and providing for attachment to a strain relief member such as a core wire, a coil, or a spiral cut portion of a hypotube, or any other strain relief structure. The attachment may be provided adhesively, or the chosen strain relief structure may be provided using a specially shaped mold for the port joint subassembly. In another embodiment, the strain relief member may be placed at least partly within a mold for making the port joint subassembly such that attachment is achieved during a molding step.
The following detailed description should be read with reference to the drawings. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention. Throughout the following description, a to number of molds are described. The molds may be made of any suitable material and may be provided with any of a variety of known coatings for aiding in a molding process. Further, while not shown, the molds can include any of the known types of injection ports allowing for injecting a molding material as well as any desired venting ports. Single or multiple infusion/vent ports may be used in a single mold, and the mold may be fabricated by any of a number of known processes with a wide variety of materials, without altering the inventive concepts described herein.
The midshaft member 22 is disposed so that, at its proximal end 22 a, it is generally circular and surrounds and is attached to the proximal member 10. At the distal end 22 b, the midshaft member 22 takes on a crescent shape, partially surrounding the inner member 18 on one side, with the outer member 16 surrounding both the midshaft member 22 and the inner member 18. It is readily observed that forming the joint 24 at the distal end 22 b of the midshaft member 22 can be time consuming and labor intensive.
During this process, of course, care must be taken to form a suitable entry 26 for a guidewire to pass into the guidewire lumen 28 defined by the inner member 18. Additional care must also be taken to preserve the integrity, and keep open, the inflation lumen 30 which passes from the interior of the proximal member 10 to the midshaft member 22 and into the outer member 16 of the distal member 12. Difficulty can arise due to the use of a tubular midshaft member 22 between the proximal member 10 and the distal member 12, as the midshaft member 22 must be carefully shaped and held in place.
The port joint 44 is shaped to include several features. A passageway 50 provides an inflation lumen connecting a first inflation lumen 52 defined by the proximal member 42 with a second inflation lumen 54 defined between the distal outer shaft 46 and the distal inner shaft 48. An opening 56 allows access to a guidewire passage 58 that connects to the guidewire lumen 62 of the distal inner shaft 48. A ramped portion 60 allows for a relatively smooth entry for the guidewire into the guidewire passage 58.
One or more of the proximal member 42, distal outer shaft 46 and distal inner shaft 48 may be attached to the port joint 44 during fabrication of the port joint 44 itself. For example, the proximal member 42 may be inserted into a mold used to make the port joint 44 prior to injecting molding material, and, due to the heat and other effects of the process, the port joint 44 and proximal member 42 can become affixed to one another as the injected material cools. In another example, the distal outer member 46 may be partially inserted into a mold used to make the port joint 44 prior to injection, and again, the distal outer member 46 and the port joint 44 can become affixed to one another as the injected material cools. Likewise, the distal inner member 48 may be partially inserted into a mold used to make the port joint 44 prior to injection, and the distal inner member 48 can become affixed to the port joint 44 as the injected material cools.
In further embodiments, more than one of the proximal member 42, distal outer shaft 46, or distal inner shaft 48 may be affixed to the port joint 44 in similar fashion during a molding step. In one such embodiment, the heat occurring during the molding step can cause the distal outer member 46 and distal inner member 48 to become affixed to one another, providing additional strength to the midshaft portion 40, particularly where the proximal member 42 is stiffer than either distal member 46, 48. In other embodiments a butt joint, rather than the lap joints illustrated, may be used.
Alternatively, a port joint may be fabricated independently. For example, an injection molding process, where molten injectate material is infused into a mold, may be used. Alternatively, the port joint may be machined by taking a piece of material (i.e. a polymer) and drilling holes and grinding the exterior to achieve the desired shape and configuration of lumens and member receiving locations.
Any suitable material, such as a polymer, may be used for constructing the port joint 44. Some suitable polymers and coatings include the following polymers and copolymers: polycarboxylic acid polymers and copolymers including polyacrylic acids (e.g., acrylic latex dispersions and various polyacrylic acid products; acetal polymers and copolymers; acrylate and methacrylate polymers and copolymers; cellulosic polymers and copolymers, including cellulose acetates, cellulose nitrates, cellulose propionates, cellulose acetate butyrates, cellophanes, rayons, rayon triacetates, and cellulose ethers such as carboxymethyl celluloses and hydroxyalkyl celluloses; polyoxymethylene polymers and copolymers; polyimide polymers and copolymers such as polyether block imides, polybismaleinimides, polyamidimides, polyesterimides, and polyetherimides; polysulfone polymers and copolymers including polyarylsulfones and polyethersulfones; polyamide polymers and copolymers including nylon 6,6, polycaprolactams and polyacrylamides; resins including alkyd resins, phenolic resins, urea resins, melamine resins, epoxy resins, allyl resins and epoxide resins; polycarbonates; polyacrylonitriles; polyvinylpyrrolidones (cross-linked and otherwise); anhydride polymers and copolymers including maleic anhydride polymers; polymers and copolymers of vinyl monomers including polyvinyl alcohols, polyvinyl halides such as polyvinyl chlorides, ethylene-vinylacetate copolymers (EVA), polyvinylidene chlorides, polyvinyl ethers such as polyvinyl methyl ethers, polystyrenes, styrene-butadiene copolymers, acrylonitrile-styrene copolymers, acrylonitrile-butadiene-styrene copolymers, styrene-butadiene-styrene copolymers and styrene-isobutylene-styrene copolymers, polyvinyl ketones, polyvinylcarbazoles, and polyvinyl esters such as polyvinyl acetates; polybenzimidazoles; ionomers; polyalkyl oxide polymers and copolymers including polyethylene oxides (PEO); glycosaminoglycans; polyesters including polyethylene terephthalates and aliphatic polyesters such as polymers and copolymers of lactide (which includes lactic acid as well as d-, l- and meso lactide), epsilon-caprolactone, glycolide (including glycolic acid), hydroxybutyrate, hydroxyvalerate, para-dioxanone, trimethylene carbonate (and its alkyl derivatives), 1,4-dioxepan-2-one, 1,5-dioxepan-2-one, and 6,6-dimethyl-1,4-dioxan-2-one (a copolymer of polylactic acid and polycaprolactone is one specific example); polyether polymers and copolymers including polyarylethers such as polyphenylene ethers, polyether ketones, polyether ether ketones; polyphenylene sulfides; polyisocyanates (e.g., U.S. Pat. No. 5,091,205 describes medical devices coated with one or more polyisocyanates such that the devices become instantly lubricious when exposed to body fluids); polyolefin polymers and copolymers, including polyalkylenes such as polypropylenes, polyethylenes (low and high density, low and high molecular weight), polybutylenes (such as polybut-1-ene and polyisobutylene), poly-4-methyl-pen-1-enes, ethylene-alpha-olefin copolymers, ethylene-methyl methacrylate copolymers and ethylene-vinyl acetate copolymers; fluorinated polymers and copolymers, including polytetrafluoroethylenes (PTFE), poly(tetrafluoroethylene-co-hexafluoropr-opene) (FEP), modified ethylene-tetrafluoroethylene copolymers (ETFE), and polyvinylidene fluorides (PVDF); silicone polymers and copolymers; polyurethanes (e.g., BAYHYDROL polyurethane dispersions); p-xylylene polymers; polyiminocarbonates; copoly(ether-esters) such as polyethylene oxide-polylactic acid copolymers; polyphosphazines; polyalkylene oxalates; polyoxaamides and polyoxaesters (including those containing amines and/or amido groups); polyorthoesters; biopolymers, such as polypeptides, proteins, polysaccharides and fatty acids (and esters thereof), including fibrin, fibrinogen, collagen, elastin, chitosan, gelatin, starch, glycosaminoglycans such as hyaluronic acid; as well as blends and copolymers of the same.
Several embodiments make use of polyether block amides (PEBAX) for the port joint 44. Some illustrative factors to consider in selecting a suitable material for the port joint 44 include consideration of the compatibility with the materials of the adjacent tubular members (i.e., the proximal member 42, the distal outer member 46 and the distal inner member 48) as well as final product properties such as tensile strength, pushability, lubricity and flexibility. The material may be chosen to provide a transition in flexibility or other characteristics between the proximal member 42 and the distal members 46, 48. In some embodiments, additional features may be used to provide enhanced or different properties including, for example, the provision of a core wire that may be placed through the port joint during the fabrication process to improve strain relief or pushability, or a heat shrink member that may be placed about the port joint to improve lubricity or tensile strength. Coatings or other treatments may also be applied.
Several of the following embodiments illustrate methods for providing a distal port subassembly or transition section. Included are embodiments illustrating attaching a proximal member or either distal member to a port joint during a molding step, as well as an embodiment where each of the proximal member and both distal members are attached simultaneously during a molding step. Various combinations of these attachment techniques may also be used.
After the molding step, the mold and mandrels are removed to leave an apparatus or catheter sub-assembly as illustrated in cross section in
Because of the shape of the mold, the port joint subassembly 96 includes several to locations adapted for attachment to other catheter parts. This includes a distal attachment location 98 which may be a collar or smoothed region sized to receive a distal outer member (not shown). The distal attachment location 98 may also include a ridge such that it can slidably receive a distal outer member (not shown) up to a controlled location, assuring repeatable engagement of a distal outer member (not shown) to the distal attachment location 98.
A proximal attachment location 100 is also illustrated. The proximal attachment location 100 may be adapted in to allow for engagement of a proximal member (not shown) and may include features similar to those of the distal attachment location 100. Either attachment location may also be provided with mechanical attachment features such as, for example, a locking collar having a ridge, threading, barbs or other mechanical features.
The guide path mandrel 92 (
A distal outer member 128 is shown partially inserted into the mold 120. Though not shown, the mold 120 may include a stop or other feature for preventing the distal outer member 128 from being passed too far into the mold. An injection stop 130 is also illustrated, the injection stop 130 having been placed over the distal ends of the mandrels 122, 126. The injection stop 130 may be placed first and the distal outer member 128 slid thereover, or the injection stop may be loaded into the distal outer member 128 and then loaded over the mandrels 122, 126.
In one embodiment, the injection stop 130 is sized to match the desired length of the distal outer member 128, and one of the mandrels 122, 126 may include a taper or other feature such that the injection stop 130 may only pass a certain distance over whichever mandrel 122, 126 is so designed. Thus, by observing the distal end of the distal outer member 128 with respect to the distal end of the injection stop 130, one may achieve a repeatable placement of the distal outer member 128 with respect to the mold 120. The distal outer member 128 may also be constructed of a transparent material to facilitate observation of the positioning of the injection stop 130. The injection stop 130 aids in containment of the injectate material (which is typically in a liquid-like form) to a space 132 defined by the mold 120 and cap 124, the mandrels 122, 126, and the distal outer member 128.
After the configuration of
In one embodiment, the guide path mandrel 122 may be a member including a lumen at least partially therethrough, with an opening at a location corresponding to the proximal end of the distal inner member 136, and an adhesive may be infused through the guide path mandrel 122 to the attachment location 138 for attaching the distal inner member 136. Although the device illustrated shows the distal inner member 136 shifted to one side of the distal outer member 128, more distal portions may allow the distal inner member 136 to be centered, or may maintain the distal inner member 136 to one side.
The mold 120 and proximal cap 124 may be removed before or after the distal inner member 136 is attached. In several embodiments the guide path mandrel 122 may remain in place to maintain a desirable, smooth guide path entry during heating used in some embodiments to attach the distal inner member 136. After attachment of the distal inner member 136, the guide path mandrel 122 may be removed, opening the guidewire entry port 140 of the member 134, the shape of which is generally controlled by the shape of the guide path mandrel 122. The inflation mandrel 126 may remain in place as a proximal member 142 is placed to engage a proximal attachment location 144. The proximal member 142 is, in an illustrative embodiment, attached at the proximal attachment location 144 by the application of localized heat. In other embodiments, the proximal attachment location 144 may include mechanical features for attaching the proximal member 142, or an adhesive may be applied. If heat is used, the guide path mandrel 122 and/or the inflation mandrel 126 may remain in place to maintain the patency of the lumens defined by each against the applied heat.
In the illustrative embodiment of
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The distal inner member 174 is attached to the member 184 at an outer location 190 as well as along an inner extension 192. The inflation mandrel (not shown) may be specially shaped to encourage creation of an attachment along an inner extension 192. The proximal member 178 is also attached along a location 194. Again, any flare or edges created at these attachment locations may be smoothed by any appropriate steps, including grinding, laser removal or localized re-melt.
A guidewire entry port 196 is created and leads into the distal inner member 174. The actual shape and any other characteristics of the guidewire entry port 196 are readily adjusted and controlled by shaping of the guide mandrel (not shown) and the distal guide port (not shown) of the mold (not shown). The distal inner member 174 is illustrated as being at an angle with respect to the distal outer member 172, which may allow for a coaxial distal section defining an annular inflation lumen. The angle may also create an easy passage for a guidewire to traverse with little friction.
The member 184 also defines an inflation lumen 198 which fluidly connects a lumen defined by the proximal member 178 to a lumen defined between the distal inner member 174 and the distal outer member 172. The inflation lumen 198 may be of any chosen shape, as controlled by the shape of the inflation mandrel.
As noted, the process illustrated in
Once the configuration shown in
After the steps illustrated above, and once the devices illustrated in
In further embodiments, multi-lumen proximal or distal members may be used. In several such embodiments, a distal member is used having more lumens than a proximal member. Further, while the Figures illustrate the use of a single lumen proximal section with a dual lumen distal section, other embodiments can include the provision of a dual lumen proximal and triple lumen distal, or any other combination.
Some embodiments include a guidewire path mandrel permanently affixed to a side of the mold, shaped for providing the guidewire entry port, with the mandrel having a distally extending tapered portion which begins at a diameter that is greater than the inner diameter of the distal inner member and ends at a diameter which is less than the inner diameter of the distal inner member, such that the distal inner member may slide over part of the mandrel but can only slide a certain distance up the mandrel. One such embodiment is shown in
For the purposes of disclosure, several of the mandrels illustrated herein are shown as generally cylindrical. In several embodiments, various non-cylindrical mandrels may be used including, for example, flattened or crescent-shaped mandrels. In several embodiments, a crescent-shaped mandrel having a flattened end is used to extend through the proximal member into the port joint. The flattened end can be shaped to partially curve around and receive the distal inner member from within the distal outer member. When a crescent-shaped mandrel is used, the inflation lumen may have a circular profile within the proximal member, transition to a crescent-shaped lumen through the port joint, and again transition to an annular lumen distal of the port joint.
Those skilled in the art will recognize that the present invention may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departures in form and detail may be made without departing from the scope and spirit of the present invention as described in the appended claims.