Patent Publication Number: US-2005143714-A1

Title: Sutureless pump connector

Description:
RELATED APPLICATION  
      This application claims priority to provisional U.S. Application Ser. No. 60/506,594, filed Sep. 26, 2003. 
    
    
     FIELD  
      This application relates to connectors for connecting medical devices.  
     BACKGROUND  
      Implantable infusion pump systems may be a preferred delivery system when it is important to deliver a therapeutic agent to a specific site or when the agent must be administered to sites in tightly controlled, yet minute dosages. Such pump systems typically contain a reservoir operably connected to a catheter. The reservoir, which holds the therapeutic agent, may be disposed within the housing of the infusion pump. The catheter is typically connected to the pump by sutures. With sutures, the catheter can disconnect from the pump between about 0.7% and about 1.4% of the time in clinical use. In addition, undesired cuts and punctures are a source of complications with catheters sutured to pumps, occurring at a rate of about 0.6% to about 6.2% of the time in clinical use. Further, use of sutures to secure catheters to pumps is a source of variability and is subject to variability in tightness. Replacement of a catheter secured by sutures may also be a source of concern, as caution is needed in removing a suture from a pump connector.  
     BRIEF SUMMARY  
      An embodiment of the invention provides a connector for securing a catheter to an implantable pump. The connector comprises a restraint configured to secure an implantable pump relative to a catheter. The connector further comprises a lock configured to secure the restraint in a secured position relative to the pump and the catheter. The restraint may be configured to engage the pump upon compression, in a radially inward direction, of at least a portion of the restraint. The lock may provide the compression. Alternatively, the restraint may be configured to engage the pump in a relaxed state.  
      An embodiment of the invention provides a catheter comprising a connector. The catheter comprises a tubular member having a distal portion and a proximal portion. The proximal portion of the tubular member is configured for connection to an implantable infusion pump. The catheter may further comprise a seal disposed about the proximal portion of the tubular member. The catheter or seal may comprise an element. The catheter further comprises a restraint disposed about the catheter or seal. The restraint is configured to engage a portion of the implantable infusion pump o secure the catheter to the pump. The restraint may comprise a mating element configured to engage the element of the catheter or seal. The restraint mating element is complementary to the element of the catheter or seal.  
      An embodiment of the invention provides a system comprising an implantable infusion pump, a catheter, and a connector configured to secure the catheter relative to the pump. The connector comprises a restraint configured to secure the proximal end of the catheter to the implantable pump. The connector further comprises a lock configured to secure the restraint in a longitudinal position relative to the pump and the catheter.  
      At least one or more of the connectors, catheters, systems, and methods described herein may provide an advantage over currently existing pump connector technology. For example, the pump connectors as described herein may connect a catheter to a pump thereby reducing implant procedure time or minimizing impact of suture technique variability. The connectors may also reduce risks associated with implantation techniques requiring sutures. Further, the ease of reversibility of a connection between a catheter and a pump by using a connector as described herein may prove advantageous. These and other advantages will become evident to one skilled in the art upon reading the disclosure herein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The advantages of the present invention will become more apparent by referring to the following detailed description and accompanying drawings, in which:  
       FIG. 1  is a drawing showing an embodiment of the invention where a catheter is connected to a pump by a sliding ring type connector;  
       FIG. 2  is a drawing showing an embodiment of the invention where a catheter is connected to a pump by a snap type connector;  
       FIG. 3  is a drawing showing an embodiment of the invention where a catheter is connected to a pump by a snap rings type connector;  
       FIG. 4  is a drawing showing an embodiment of the invention where a catheter is connected to a pump by a sliding ring type connector;  
       FIG. 5  is a drawing showing an embodiment of the invention where a catheter is connected to a pump by a screw on ring type connector;  
       FIG. 6  is a drawing showing an embodiment of the invention where a catheter is connected to a pump by a sliding type connector;  1   
      FIGS.  7 A-C is a drawing showing an embodiment of the invention where a catheter is connected to a pump by a sliding type connector (variation of embodiment shown in  FIG. 6 )  
       FIG. 8  is a drawing showing a cross section of a catheter connected to a pump by a connector according an embodiment in  FIG. 7 ;  
       FIG. 9  is a drawing showing a cross section of a catheter connected to a pump by a connector according an embodiment in  FIG. 7 ; and  
       FIG. 10  is a drawing showing an embodiment of the invention where a stopping mechanism is affixed to a catheter to prevent a connector ring from sliding off the catheter. 
    
    
      The drawings are not necessarily to scale. Like numbers refer to like parts or steps throughout the drawings. However, it should be understood that use of like reference numbers are for convenience and should not be construed as limiting. For example, the use of the number “10” to refer to “lock” in both  FIGS. 1 and 2  does not indicate that the lock of  FIG. 1  must take the form of the lock shown in  FIG. 2 , as is clearly depicted in the figures.  
     DETAILED DESCRIPTION  
      [20] In the following descriptions, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration several specific embodiments of the invention. It is to be understood that other embodiments of the present invention are contemplated and may be made without departing from the scope or spirit of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense.  
      I. Overview  
      A. Connector  
      An embodiment of the invention provides a connector for securing a catheter  50  to an implantable pump  300 . The connector comprises a restraint  20  configured to secure an implantable pump  300  relative to a catheter  50 . The connector further comprises a lock  10  configured to secure the restraint  20  in a secured position relative to the pump  300  and the catheter  50 .  
      In an embodiment, the restraint  20  is configured to engage a portion of the pump  300 , such as a port  40  or portion thereof, upon compression, in a radially inward direction, of at least a portion of the restraint  20 . For example, the restraint  20  may comprise an extension member  120  comprising a proximal portion and a distal portion and configured to secure the catheter  50  to the implantable pump  300 . At least a portion of the extension member  120  is compressible in a radially inward direction, and at least a portion of the proximal portion of the extension member  120  may be configured to engage the pump  300  when the extension member  120  is compressed. For example, the extension member  120  may comprise a feature  90  complementary to a pump feature  80 , and the extension member feature  90  may grippingly engage the pump feature  80  when the extension member  120  is compressed. The extension member feature  90  and the complementary pump feature  80  may be shaped in any manner such that the extension member feature  90  engages the pump feature  80  to secure the restraint  20  to the pump  300 . For example, the pump feature  80  may comprise an indentation, such as a groove, and the extension member feature  90  may comprise a protrusion, or the extension member feature  90  may comprise an indentation and the pump feature  80  may comprise a protrusion. The lock  10  may be configured to compress the extension member  120  of the restraint  20  to secure the extension member  120  of the restraint  20  to the implantable pump  300 . The extension member  120  may be expandable. In an embodiment, the extension member  120  is expandable such that upon relief of a compressing force the proximal portion of the extension member is capable of being expanded substantially to its pre-compressed dimensions. The extension member  120  may be self-expandable or may be expanded by applying a radially outward force to the extension member  120 , preferably to the proximal portion of the extension member  120 .  
      In an embodiment, the restraint  20  is configured to engage a portion of the pump  300 , such as a port  40  or portion thereof, in a relaxed state. The restraint  20  may comprise an extension member  120  configured to engage the pump  300 , and at least a portion of the extension member  120  may be extendable in a radially outward direction. The restraint  20  and its extension member  120  preferably have sufficient resiliency to return to substantially the pre-expanded dimensions upon release of a radially outward expanding force. The extension member  120  may comprise a feature  90  complementary to a feature  80  of a portion of the pump  300  to which the restraint  20  engages, and the extension member feature  90  may be configured to grippingly engage the pump feature  80 . The extension member feature  90  and the complementary pump feature  80  may be shaped in any manner such that the extension member feature  90  engages the pump feature  80  to secure the restraint  20  to the pump  300 . For example, the pump feature  80  may comprise an indentation and the extension member feature  90  may comprise a protrusion, or the extension member feature  90  may comprise an indentation and the pump feature  80  may comprise a protrusion. The lock  10  is configured to prevent the restraint  20  from disengaging the pump  300 .  
      In an embodiment, the connector comprises a tab  70  configured to secure the lock  10  in a position about the restraint  20 . The restraint  20  may comprise the tab. Preferably, a distal portion of the restraint  20  comprises the tab  70 . The distal portion of the restraint  20  comprising the tab  70  may be compressible in a radially inward direction, allowing the lock  10  to be disposed about the restraint  20  removed from about the restraint  20 . The distal portion of the restraint  20  comprising the tab  70  is preferably expandable, so that the tab  70  may secure the lock  10  in a position relative to the restraint  20 . The distal portion of the restraint  20  comprising the tab  70  is preferably expandable such that upon relief of a radially inward compressing force the distal portion of the restraint  20  comprising the tab  70  is capable of being expanded to substantially to its pre-compressed dimensions. In an embodiment, the distal portion of the restraint  20  comprising the tab  70  is self-expandable. In a preferred embodiment, the lock  10  is configured to slide over the tab  70 , in e.g. a linear or helical manner, compressing the distal portion of the restraint  20  comprising the tab  70  as the lock  10  slides over the tab  70 . The distal portion of the restraint  20  comprising the tab  70  is configured to expand substantially to its pre-compressed dimensions after the lock  10  is slid over the tab  70 , such that the tab  70  secures the lock  10  in a position about the restraint  20 . The size and shape of the tab  70  can be a compromise between ease of use and potential damage to the catheter  50 . Of course, the lock  10  may comprise an expandable portion configured to expand in a radially outward direction upon sliding over the tab  70 . If the lock  10  comprises an expandable portion, the expandable portion of the lock  10  is preferably contractible such that contraction of the expandable portion of the lock  10  prevents the lock  10  from sliding over the tab  70 , thereby securing the lock  10  a position about the restraint  20 . Of course, a distal portion of the restraint  20  comprises the tab  70  may be compressible and portion of the lock  10  may be expandable.  
      In addition to engaging the pump  300 , the connector engages a catheter  50  to secure the catheter  50  in a position relative the pump  300 . The connector may engage the catheter  50  via the restraint  20 . For example, the restraint  20  may comprise a mating element  140  configured to engage a complementary element  150  of the catheter  50 . The restraint mating element  140  and the complementary catheter element  150  may be shaped in any manner such that the restraint mating element  140  engages the catheter element  150  to secure the restraint  20  to the catheter  50 . For example, the restraint mating element  140  may comprise an indentation and the complementary catheter element  150  may comprise a protrusion, or the restraint mating element  140  may comprise a protrusion and the complementary catheter element  150  may comprise an indentation. A portion of the catheter  50  may be tapered and may be configured to engage the lock  10  at location of the tapered portion having an outer diameter substantially similar to an inner diameter of the lock  10 .  
      In an embodiment, the restraint  20  and the lock  10  are a single piece. In an embodiment, the restraint  20  and the lock  10  are separate pieces and may individually comprise one or more components.  
      A connector according to various embodiments of the invention may be secured to a pump  300  or a catheter  50  through any means. For example, a physician may secure a connector to a pump  300  by hand. Tools may also be used as deemed necessary by the physician during the connection process. Any tool the physician deems suitable may be used. Preferably, tools are not needed to connect the catheters  50  and connectors to the pump  300 . If tools are needed, the tools are preferably standard tools that can be found in operating rooms.  
      Any biocompatible and biostable material, or combinations thereof, capable of performing the desired securing function may be used to make a connector or components thereof. Nonlimiting examples of suitable material include titanium, polycarbonate, polysulfonate, nylon, polyurethane, polyether ether ketone and polypropylene, P1700 available from Solvay (BP Amoco) Polymers Europe and Gharda is an example of a suitable polysulfonate.  
      An example of a suitable nylon is grilamid nylon 12, TR 55 available from EMS-Grivory. An example of a suitable polyurethane is polyurethane 75D, Tecothane TT-1075DM available from Thermedics division of Viasys Healthcare. The lock  10  and restraint  20  may be made of the same or different material. For example, the lock may be made of titanium and the restraint may be made of polysulfonate.  
      In an embodiment, the restraint  20  and the lock  10  of a connector are different colors. Different colored restraints  20  and locks  10  may be desirable. For example, when a restraint  20  comprises a tab  70  to maintain the lock in position, the tab  70  will be more readably identifiable when the tab  70  is a different color than the lock  10 . If the tab  70  is releasable, the different colored (relative to the lock  10 ) tab  70  can be readily identified to facilitate disconnecting catheter  50  from a pump  300 .  
      Any coloring agent may be used to color lock  10  and a restraint  20 . Preferably, coloring agents are biocompatible. The duration of biocompatible coloring agents should be considered. For example, some coloring agents are currently deemed suitable for short-term implant. Some are suitable for long-term implant. Examples of biocompatible coloring agents suitable for long term implant include TiO 2  and carbon black.  
      A connector according to an embodiment of the invention may be compatible with Medtronic&#39;s model SynchroMed EL, SynchroMed II, and/or IsoMed pumps  300 . Preferably a connector resists accidental disconnection of a catheter  50  from a pump  300  after implantation. Further, it is preferred that a connector is readily disconnectable after implantation, even after fibrosis.  
      B. Catheter  
      In embodiment, the invention provides a catheter  50 . The catheter  50  comprises a tubular member  170  comprising a distal portion and a proximal portion. The proximal portion is configured for connection to an implantable infusion pump  300 . The catheter may further comprise a seal  60 . The seal  60  may be molded to the catheter  50 . The seal  60  may be made of any material suitable for forming a fluid barrier. For example, the seal may be made of silicone. The seal  60  is preferably disposed about the proximal portion of the tubular member  170 . The seal comprises a seal element  150 . The seal element  150  may be a catheter element  150  as described herein. The catheter further comprises a restraint  20  disposed about the seal  60  and configured to engage a portion of an implantable infusion pump  300  to secure the catheter  50  to the pump  300 . The restraint  20  may be part of a connector as described herein. The restraint  20  may be a restraint  20  as described herein and comprises a mating element  140  configured to engage the seal element  150 . The catheter  50  may further comprise a lock  10  as described herein. The catheter may further comprise a lock stopping mechanism  100  to prevent the lock  10  from sliding off the catheter  50 . The lock stopping mechanism  100  is preferably located distally to the restraint  20 .  
      C. System  
      In an embodiment, the invention provides a system. The system comprises a catheter  50  having a proximal end and a distal end. The system further comprises an implantable infusion pump  300 . The system additionally comprises a connector. The connector comprises a restraint  20  configured to secure the proximal end of the catheter  50  relative to the implantable pump  300 . The connector further comprises a lock  10  configured to secure the restraint  20  in a position relative to the pump  300  and the catheter  50 . The connector, catheter  50 , restraint  20 , and lock  10  may be any connector, catheter  50 , restraint  20 , and lock  10  as described herein. The pump  300  may comprise a port to which the catheter  50  may be secured via the connector. The port  40  may comprise a port feature  80 . The port feature  80  may be a pimp feature  80  as described herein. The restraint  20  may comprise a feature  90  complementary to the port feature  80 , wherein the restraint feature  90  is configured to engage the port feature  80  to secure the restraint  20  to the pump  300 .  
      D. Methods  
      Various methods for securing a catheter  50  to an implantable infusion pump  300  are contemplated. Based on the disclosure herein, many such methods will be readily evident to one skilled in the art. By way of example, an embodiment of the invention provides a method for securing a catheter  50  to an implantable infusion pump  300 . The method comprises inserting a portion of a port  40  of the pump  300  into the catheter  50 . The method further comprises positioning a restraint  20  about the port  40  and the catheter  50  such that the restraint  20  engages the port  40  and the catheter  50 . The method further comprises sliding a lock  10  over the restraint  20  to secure the restraint  20  in a position relative to the pump  300  and the catheter  50 .  
      Various methods for releasing a catheter  50  securely coupled to an implantable infusion pump  300  are contemplated. Based on the disclosure herein, many such methods will be readily evident to one skilled in the art. By way of example, an embodiment, the invention provides a method for releasing a catheter  50  from an implantable pump  300 . The method comprises depressing a tab  70  on a restraint  20  that is securely coupling the catheter  50  relative to the implantable pump  300 . The method further comprises sliding a lock  10  over the depressed tab  70  to remove the lock  10  from the restraint  20 . The method further comprises uncoupling the catheter  50  from the pump  300 .  
      II. FIGS.  
      Referring to  FIG. 1 , a catheter  50  connected to a port  40  of a pump  300  by a sliding type ring connector is shown. The connector comprises a restraint  20  and a lock. The restraint  20  has a proximal portion and a distal portion. The proximal portion of the restraint comprises a plurality of extension members  120 . A proximal portion of extension member  120  is configured to engage the port  40 . The restraint  20  may be slid about the catheter  50 . The lock  10  may be slid about the restraint  20 . Sliding the lock  10  from a distal to proximal direction about the restraint  20  may result in the lock  10  sliding over tab  70 . The tab  70  may be compressed radially inward as lock  10  slides over tab  70 . Alternatively, the lock  10  may be expanded radially outward as lock  10  is slid over the tab  70 . After the lock  10  is slid over the tab  70 , the tab  70  expands or the lock  10  contracts such that the lock  10  is held in a longitudinal position relative to the restraint  20  by the tab  70 . Of course there may be a plurality of tabs  70 . The lock  10  ensures that the restraint  20  remains in a substantially fixed longitudinal position relative to port  40 . The restraint  20  comprises a flange  500  to ensure the lock  10  remains in a locked position. The tabs  70  may be depressed to allow the lock  10  to be removed from the restraint  20 . The flange  500  has an outer diameter greater than the diameter of an opening on the proximal portion of the lock  10 .  
      The catheter  50  in  FIG. 1  comprises a seal  60 . The seal  60  is disposed about the proximal portion of the catheter  50 . The seal  60  is tapered, having its smallest diameter distally in the taper and its largest diameter proximally in the taper. The distal portion of the restraint  20  comprises an opening having a diameter. The restraint  20  may be slid from a distal to proximal direction over the catheter  50  until the opening of the restraint  20  engages a portion of the taper of the seal  60  having a substantially similar diameter of the opening. Locking the restraint  20  in a position about the port  40 , thereby secures the catheter  50  relative to the pump  300 .  
       FIG. 2  shows a seal  60  of a catheter  50  connected to a port  40  of a pump  300  by a snap type connector.  FIG. 3  shows a seal  60  of a catheter  50  connected to a port  40  of a pump  300  by a snap rings type connector.  FIGS. 2A and 3A  show an unlocked position and  FIGS. 2B and 3B  show a locked position.  
      Referring to  FIG. 4 , an embodiment of a sliding ring type connector, a catheter  50 , and a system of the invention is shown. The catheter  50  comprises a tapered seal  60  as discussed for  FIG. 1 . The restraint  20  comprises an opening through its distal end. The opening has a diameter similar to a portion of the tapered seal  70 . The proximal portion of the restraint  20  comprises a plurality of extension members  120  configured to engage a port  40  of a pump  300 . The port  40  comprises a feature  80 , shown as a groove in  FIG. 4 . The extension members  120  comprises a complementary feature  90 , shown as protrusions. A feature  90  (protrusion) of the extension member  120  is configured to engage the feature  80  (groove) of the port  40 . The feature  90  (protrusion) of the extension member  120  may engage the feature  80  (groove) of the port  40  when compressed or in its relaxed state.  
      The lock  10  shown in  FIG. 4  comprises a distal opening having a diameter. The diameter of the distal opening of the lock  10  is less than the outer diameter of flanges  500  of extension members  120  of restraint  20 , such that when lock  10  is slid over restraint  20  into a locked position the lock  10  does not slide off restraint  20  proximally.  
      Referring to  FIG. 5 , an embodiment of a screw on lock type connector, a catheter  50 , and a system of the invention is shown. The restraint  20  shown in  FIG. 5  comprises a plurality of grooves on its exterior surface. The lock  10  comprises complementary protrusions (not shown) allowing lock  10  to be screwed into a secured position about restraint  10 . Otherwise, the connector of  FIG. 5  may be used to secure catheter  50  to port  40  in a similar manner to the connectors of  FIGS. 1 and 4 . Alternatively, as shown in  FIG. 5 , the seal  60  comprises a feature  80 , allowing for the connector of  FIG. 5  to be used to secure catheter  50  to port  40  in a similar manner to the connectors of  FIGS. 8 and 9 .  
      Referring to  FIGS. 6-10 , a catheter  50  connected to a port  40  of an implantable pump  300  by a sliding type connector is shown. The connector comprises a restraint  20  configured to secure the catheter  50  relative to the implantable pump  300 . The connector further comprises a lock  10  configured to secure the restraint  20  in a secured position relative to the pump  300  and the catheter  50 . The restraint  20  is comprises a plurality of extension members  120 . Extension member  120  comprises a feature  90  configured to engage a complementary feature  80  of port  40 . Extension member feature  90  may engage complementary feature  80  of port in extension member&#39;s  120  relaxed state or upon compression. Lock  10  may compress extension member  120  such that feature  90  of engages port feature  80 . If extension member  120  engages port  40  in a relaxed state, extension member  120  may be expanded in a radially outward direction and then un-expanded to facilitate placement of extension member  120  about port  40  such that extension member feature  90  will engage port feature  80 .  
      Restraint in  FIGS. 6-10  engages catheter  50 . Catheter  50  comprises a tapered seal  60 , like the catheter described in  FIG. 1 . Restraint  20  comprises an opening towards or at its distal end. The restraint distal opening has a diameter similar to a portion of the tapered portion of the seal  60 , where restraint  20  may engage seal  60 . Seal  60  also comprises an element  150  and restraint  20  comprises a complementary mating element  140  configured to engage element  150  to further facilitate retaining connector in a longitudinal direction relative to catheter  50 . Complementary mating element  140  may comprise an undercut.  
      Lock  10  in  FIGS. 6-10 , comprises an opening  600  having a diameter smaller than flange  500  of restraint  20 , preventing lock from moving too far proximally relative to the restraint. Opening  600  of lock  10  has a diameter less than the outer diameter formed by tabs  70 , such that after lock is slid over tabs  70 , tabs  70  prevent lock  10  from sliding off restraint  20  in a distal direction. A portion of the lock  10  near opening  600  having a smaller diameter than flange  500  has a length  800 . The length  800  of this portion of the lock  10  is less than or equal to a length  810  between tab  70  and flange  500  of restraint, thereby allowing the restraint  20  to retain the lock  10  in a defined range of longitudinal positions relative to restraint  20 . Lock  10  may also comprise a protrusion  910  for ergonomic purposes to facilitate sliding lock  10  into position about restraint  20 .  
       FIG. 10  shows a catheter  50  comprising a lock stopping mechanism  100 . The lock stopping mechanism  100  is configured to prevent the lock  10  or restraint  20  from sliding off the distal end of catheter  50 . The lock stopping mechanism  100  or a portions thereof have a diameter greater than the distal opening of the restraint and the opening  600  of the lock.  
      Various embodiments of the invention are disclosed. One skilled in the art will appreciate that the present invention can be practiced with embodiments other than those disclosed.  
      The disclosed embodiments are presented for purposes of illustration and not limitation, and the present invention is limited only by the claims that follow.