Abstract:
A multi-lumen catheter assembly with a two-piece hub is disclosed. The catheter includes a distal portion having a plurality of catheter lumens, wherein each of the plurality of catheter lumens includes a distal tip and a proximal lumen portion. The distal portion further includes a distal hub portion slidably disposed over the proximal lumen portion, wherein the distal hub portion includes a pivoting locking member. The catheter assembly further includes a proximal portion having a plurality of catheter extensions, wherein each of the plurality of catheter extensions fluidly communicates with at least one of the plurality of catheter lumens. The proximal portion also includes a proximal hub portion having a locking receiver, wherein the pivoting locking member is releasably engaged with the locking receiver.

Description:
CROSS-REFERENCE TO RELTATED APPLICATION  
       [0001]    The present application claims priority from U.S. Provisional Patent Application Serial No. 60/434,304, filed on Dec. 18, 2002. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to a multi-lumen catheter having a hub with multiple pieces that lock together.  
         BACKGROUND OF THE INVENTION  
         [0003]    Catheters for the introduction or removal of fluids may be located in various venous locations and cavities throughout the body for introduction of fluids to the body or removal of fluids from the body. Such catheterization may be performed by using a single catheter having multiple lumens. A typical example of a multiple lumen catheter is a dual lumen catheter assembly in which one lumen introduces fluid and the other lumen removes fluid. An example of such a dual lumen catheter assembly is the ASH SPLIT-CATH® catheter.  
           [0004]    Generally, to insert any catheter into a blood vessel, the vessel is identified by aspiration with a long hollow needle in accordance with the well known Seldinger technique. When blood enters a syringe attached to the needle, indicating that the vessel has been found, a thin guidewire is then introduced, typically through a syringe needle or other introducer device into the interior of the vessel. The introducer device is then removed, leaving the guidewire within the vessel. The guidewire projects beyond the surface of the skin. At this point, several options are available to a physician for catheter placement. The simplest is to pass a catheter into the vessel directly over the guidewire. The guidewire is then removed, leaving the catheter in position within the vessel. However, this technique is only possible in cases where the catheter (for example, a small diameter dual lumen catheter) is of a relatively small diameter, made of a stiff material, and not significantly larger than the guidewire. If the catheter to be inserted is significantly larger than the guidewire, a dilator device is passed over the guidewire to enlarge the opening in the vessel. The catheter is then passed over the guidewire into the vessel, and the guidewire and dilator are then removed, leaving the catheter in position within the vessel.  
           [0005]    For chronic catheterization, in which the catheter is intended to remain inside the patient for an extended period of time, such as for weeks or even months, it is typically desired to subcutaneously tunnel the catheter into the patient using various tunneling techniques. The catheter is typically tunneled into the patient prior to inserting the catheter into the patient&#39;s vein. However, there may be times when it is more advantageous, due to such things as the patient or the implanting surgeon&#39;s skill, to perform the tunneling after the catheter is implanted in the patient. For some catheters, though, such as multiple lumen catheters with a hub and with bonded luers on the proximal ends of the catheters, it is impractical to perform the tunneling after the catheter is installed in the patient. It would be beneficial to provide a catheter assembly that provides a surgeon with alternative installation procedures for installing the catheter that better suit either the patient&#39;s needs or the surgeon&#39;s skills.  
           [0006]    Further, for chronically installed catheters, portions of the catheter external to the patient occasionally fail, such as for instance, by leaking and/or by the introduction of foreign particles such as dirt, bacteria, and the like into the catheter. Such failures include worn or broken clamps or broken luers. In order to correct these problems, it is presently necessary to remove the entire catheter from the patient, causing additional trauma and risking additional medical problems to the patient. It would be beneficial to provide a catheter in which the proximal portion of the catheter may be removed and replaced without disturbing the distal portion of the catheter inside the patient.  
         BRIEF SUMMARY OF THE INVENTION  
         [0007]    Briefly, the present invention provides a detachable hub for a catheter, comprising a first portion having a first distal end, a first proximal end, and a longitudinal channel extending therethrough between the first distal end and the first proximal end, wherein the first proximal end includes a pivoting locking member. The hub further comprises a second portion having a second distal end, and a second proximal end, wherein the second distal end includes a locking receiver, and wherein the longitudinal channel of the first portion of the hub is sized to allow the first proximal end to be disposed over the second distal end such that the pivoting locking member is engageable with the locking receiver.  
           [0008]    Additionally, the present invention provides a multi-lumen catheter assembly, comprising a distal portion having a plurality of catheter lumens, wherein each of the plurality of catheter lumens includes a distal tip and a proximal lumen portion. The distal portion further comprises a distal hub portion slidably disposed over the proximal lumen portion, wherein the distal hub portion includes a pivoting locking member. In addition to the distal hub portion, the hub of the catheter assembly also comprises a proximal hub portion having a plurality of catheter extensions, wherein each of the plurality of catheter extensions fluidly communicates with at least one of the plurality of catheter lumens. The proximal hub portion has a locking receiver, wherein the pivoting locking member of the distal hub portion of the hub is releasably engaged with the locking receiver of the proximal hub portion.  
           [0009]    The present invention also provides a method of inserting a multi-lumen catheter assembly into a patient. The method comprises inserting a distal end of each of a plurality of catheter lumens into a patient&#39;s blood vessel; connecting a proximal end of each of the plurality of catheter lumens to a tunneling device; forming a subcutaneous tunnel with the tunneling device; pulling the proximal ends of the plurality of catheter lumens through the subcutaneous tunnel; disconnecting the tunneling device from the proximal ends of the plurality of catheter lumens; sliding a first portion of a catheter hub over the proximal ends of the plurality of catheter lumens, wherein the first portion of the catheter hub comprises a pivoting locking member; connecting a second portion of the catheter hub to each of the plurality of catheter lumens, wherein the second portion of the catheter hub comprises a locking receiver; and engaging the pivoting locking member with the locking receiver. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate the presently preferred embodiments of the invention, and, together with the general description given above and the detailed description given below, serve to explain the features of the invention. In the drawings:  
         [0011]    [0011]FIG. 1 is a side view of a catheter assembly according to a preferred embodiment of the present invention.  
         [0012]    [0012]FIG. 2 is a sectional view of a pair of catheter lumens taken along line  2 - 2  of FIG. 1.  
         [0013]    [0013]FIG. 3 is a sectional view of an alternative embodiment of a pair of catheter lumens.  
         [0014]    [0014]FIG. 4 is an exploded view of a catheter hub according to a preferred embodiment of the present invention.  
         [0015]    [0015]FIG. 5 is a sectional view of the catheter hub taken along line  5 - 5  of FIG. 4.  
         [0016]    [0016]FIG. 6 is a side exploded view showing the elements of the catheter assembly.  
         [0017]    [0017]FIG. 7 is a perspective view of a catheter tunneler connected to proximal ends of the catheter lumens of FIG. 2.  
         [0018]    [0018]FIG. 8 is a perspective view of a hub disassembly tool. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]    In the drawings, like numerals indicate like elements throughout. Certain terminology is used herein for convenience only and is not to be taken as a limitation on the present invention. The words “proximal” and “distal” refer to directions away from and closer to, respectively, the insertion tip of the catheter in the catheter assembly according to the present invention. The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import. The following describes preferred embodiments of the invention. However, it should be understood based on this disclosure, that the invention is not limited by the preferred embodiments described herein.  
         [0020]    Referring to FIG. 1, a catheter assembly  100  incorporating a snap hub  150  according to a first preferred embodiment of the present invention is shown. The catheter assembly  100  includes a distal end  102  and a proximal end  104 . The distal end  102  includes a plurality of catheter lumens  106 ,  108 . While two catheter lumens  106 ,  108  are shown, those skilled in the art will recognize that a catheter assembly utilizing more than two catheter lumens  106 ,  108  is within the scope of the present invention. As seen in FIG. 2, the catheter lumens  106 ,  108  preferably have generally “D-shaped” cross-sections along at least a majority of the length of each catheter lumen  106 ,  108 , with the generally flat portion of the D-shape of each catheter lumen  106 ,  108  in juxtaposed relation with each other. The generally flat portion of the D-shape of each catheter lumen  106 ,  108  is preloaded to bow outward slightly to improve sealing around each catheter lumen  106 ,  108 , as is described in more detail herein.  
         [0021]    Referring back to FIG. 1, proximal ends  106   a ,  108   a  of the catheter lumens  106 ,  108  are preferably joined together, with distal ends  106   b ,  108   b  of the catheter lumens  106 ,  108  preferably splittable from each other, such as the catheter lumens of the ASH SPLIT-CATH®catheter, manufactured and sold by Medical Components, Inc., of Harleysville, Pa. Alternatively, the distal ends  106   b ,  108   b  of the catheter lumens  106 ,  108  may be fixedly split from each other. In a second preferred embodiment of catheter lumens, as shown in FIG. 3, the catheter lumens  106 ′,  108 ′ may have generally circular cross-sections along at least a majority of the length of each catheter lumen. The catheter lumens  106 ′,  108 ′ may be fixedly or splittably joined together along at least a portion of their lengths, or the catheter lumens  106 ′,  108 ′ may be separate and distinct from each other.  
         [0022]    As seen in FIG. 1, catheter lumen  106  is shorter than catheter lumen  108 . With this configuration, it is preferred that the catheter lumen  106  be used to draw fluid, such as blood, from the patient, and that the catheter lumen  108  be used to return the fluid to the patient after treatment, such as hemodialysis.  
         [0023]    The proximal end  104  of the catheter assembly  100  includes a pair of extension tubes  110 ,  112  that fluidly communicate with the catheter lumens  106 ,  108  through the hub  150 , as is described in more detail herein. Each extension tube  110 ,  112  includes a connection device  114 , such as a luer lock, disposed at the most proximal end of the extension tubes  110 ,  112 . An extension clamp  116  is disposed over each extension tube  110 ,  112 , between each connection device  114  and the hub  150 . Preferably, the extension clamp  116  is a Roberts clamp, or some other clamp known to those skilled in the art.  
         [0024]    Referring now to FIGS. 4 and 5, the hub  150  is comprised of a distal portion  152  and a separable proximal portion  154 . The distal portion  152  includes a distal end  156  and a proximal end  158 . A longitudinal channel  160  extends through the distal portion  152  between the distal end  156  and the proximal end  158 . As is seen in FIG. 5, the channel  160  is wider at the proximal end  158  than at the distal end  156 . The channel  160  includes a shoulder  162  that narrows the channel  160  between the proximal end  158  and the distal end  156 . The channel  160  is sized to allow the distal portion  152  of the hub  150  to be disposed over the proximal ends of the catheter lumens  106 ,  108 .  
         [0025]    The distal portion  152  of the hub  150  further includes first and second pivoting locking members  164 ,  166 , respectively, which serve to lock the distal portion  152  to the proximal portion  154 . Each locking member  164 ,  166  includes a pivot axle  168 , about which each locking member  164 ,  166  rotates. Proximate to each respective pivot axle  168 , the locking members  164 ,  166  each include a cam  170 ,  172 , respectively, which engage the proximal portion  154  when the locking members  164 ,  166  are moved to a locking position. Each locking member  164 ,  166  further includes a recess  174 ,  176 , respectively, that engages a proximal end of the proximal portion  154  when the locking members  164 ,  166  engage the proximal portion  154 .  
         [0026]    The distal end  156  of the distal portion  152  further includes a suture wing  178  disposed thereon. Preferably, the suture wing  178  is rotatable about the longitudinal channel  160 , although those skilled in the art will recognize that the suture wing  178  may be fixed to the distal portion  152 , instead. Preferably, the distal portion  152  and the suture wing  178  are each constructed from pellethane, although those skilled in the art will recognize that the distal portion  152  and the suture wing  178  may be constructed from other suitable materials. An o-ring  180  may be disposed within the channel  160  proximate to the distal end  156  of the distal portion  152 . The o-ring  180  provides a generally leak-proof seal between the catheter lumens  106 ,  108  and the distal portion  152  of the hub  150  when the distal portion  152  is disposed over the catheter lumens  106 ,  108 . However, those skilled in the art will recognize that the o-ring  180  may be omitted entirely.  
         [0027]    The proximal portion  154  of the hub  150  includes a distal end  182  and a proximal end  184 . The distal end  182  of the proximal portion  154  includes first and second hub cannulae  186 ,  188 , which are sized and shaped to enable the proximal ends  106   a ,  106   b  of the catheter lumens  106 ,  108  to be fittingly disposed over a respective hub cannula  186 ,  188 , respectively.  
         [0028]    The distal end  182  of the proximal portion  154  of the hub  150  also includes first and second locking receivers  190 ,  192 , respectively. The locking receivers  190 ,  192  are each preferably generally saddle-shaped such that, when the proximal end  158  of the distal portion  152  is disposed over the distal end  182  of the proximal portion  154 , the cams  170 ,  172  engage their respective locking receiver  190 ,  192 .  
         [0029]    The proximal end  184  of the proximal portion  154  of the hub  150  includes first and second channels  194 ,  196  that each have a distal end  194   a ,  196   a  fluidly communicating with a respective hub cannula  186 ,  188 . A proximal end  194   b ,  196   b  of each channel  194 ,  196  is sized to accept the extension tubes  110 ,  112 , respectively so that the proximal ends  194   b ,  196   b  each fluidly communicate with a respective extension tube  110 ,  112 . The channel  194  fluidly communicates with the hub cannula  186  and the channel  196  fluidly communicates with the hub cannula  188  so that channels are formed through the length of the second portion  154 .  
         [0030]    Further, the proximal end  184  of the proximal portion  154  includes projections  198 ,  200  extending therefrom, generally away from the channels  194 ,  196 , respectively. The projections  198 ,  200  are sized and disposed such that, when the proximal end  158  of the distal portion  152  is disposed over the distal end  182  of the proximal portion  154 , the projections  198 ,  200  are received within the recesses  174 ,  176 , respectively. The projections  198 ,  200  are preferably generally orthogonally shaped; however, the proximal edge  198   a ,  200   a  of each projection  198 ,  200  is preferably slightly chamfered to allow the respective recess  174 ,  176  to fit over the proximal edge  198   a ,  200   a.    
         [0031]    The proximal end  158  of the distal portion  152 , as well as the channel  160 , are sized to allow the proximal end  158  of the distal portion  152  to be disposed over the distal end  182  of the distal portion  154  such that each cam  170 ,  172  is engageable with a respective locking receiver  190 ,  192 .  
         [0032]    Preferably, the proximal end  184  of the proximal portion  154  is constructed from pellethane and the distal end  182  of the proximal portion  154  is constructed from tecoplast, although those skilled in the art will recognize that both the proximal end  184  and the distal end  182  may be constructed from other, suitable materials. Further, the hub cannulae  186 ,  188  are preferably constructed from 304 stainless steel, although those skilled in the art will recognize that other suitable materials may be used.  
         [0033]    While it is preferred that the distal portion  152  Of the hub  150  includes the pivoting locking members  164 ,  166  and that the proximal portion  154  of the hub  150  includes the first and second locking receivers  190 ,  192 , those skilled in the art will recognize that the distal portion  152  of the hub  150  may incorporate the locking receivers  190 ,  192  and that the proximal portion  154  of the hub  150  may incorporate the pivoting locking members  164 ,  166  without departing from the scope of the present invention.  
         [0034]    The catheter assembly  100  is preferably provided for use in kit form, with the catheter  102 , the distal portion  152  of the hub  150 , and the proximal portion  154  of the hub  150 , as well as a compression ring  202 , all separate, as shown in FIG. 6. The catheter assembly  100  is inserted into a patient by inserting the distal end of the catheter  102  into the patient&#39;s blood vessel according to known techniques. Referring now to FIG. 7, a distal end  204   a  of a dual lumen catheter tunneler  204  is connected to the proximal ends  106   a ,  108   a  of each catheter lumen  106 ,  108 . An embodiment of a preferred dual lumen catheter tunneler  204  is disclosed in U.S. Provisional Patent Application Serial No. 60/434, 303, filed on Dec. 18, 2002, which is owned by the Assignee of the present invention and which is incorporated herein by reference in its entirety. A proximal end  204   b  of the tunneler  204  is inserted under the patient&#39;s skin forming a subcutaneous tunnel. The proximal ends  106   a ,  108   a  of the catheters lumens  106 ,  108  are pulled through the subcutaneous tunnel, and the tunneler  204  is disconnected from the catheter lumens  106 ,  108 .  
         [0035]    Referring back to FIGS. 5 and 6, the proximal ends  106   a ,  108   a  of the catheter lumens  106 ,  108  are inserted into the channel  160  from the distal end  156  of the distal portion  152  of the hub  150  and the distal portion  152  of the hub  150  is slid over the proximal ends  106   a ,  108   a  of the catheter lumens  106 ,  108 . Optionally, but preferably, the compression ring  202  is next slid over the proximal ends  106   a ,  108   a  of the catheter lumens  106 ,  108 . The hub cannulae  186 ,  188 , whose distal end portions are disposed in the proximal portion  154  of the hub  150 , are next slid into the proximal ends  106   a ,  108   a  of the catheter lumens  106 ,  108 , respectively, so that the proximal portion  154  of the hub  150  and the catheter lumens  106 ,  108  are in fluid communication with each other. The slight outward bow of the generally flat portion of the catheter lumens  106 ,  108  improves sealing between the lumens  106 ,  108  and the hub cannulae  186 ,  188  when the compression ring  202  is compressed. Further, the hub cannulae  186 ,  188  generally bias toward each other to again improve the sealing. The compression ring  202  is slid proximally over the catheter lumens  106 ,  108  so that the compression ring  202  is disposed over the hub cannulae  186 ,  188 . The compression ring  202  serves to seal the catheter lumens  106 ,  108  on the hub cannulae  186 ,  188 .  
         [0036]    Next, the distal portion  152  of the hub  150  is advanced toward the proximal portion  154  of the hub  150 . When the distal portion  152  and the proximal portion  154  are engaged with each other, the locking members  164 ,  166  are pivoted about their pivot axles  168  so that the cam  170  is disposed in the saddle  190  and so that the cam  172  is disposed in the saddle  192 . The eccentricity of the cams  170 ,  172  exerts a camming action between the cams  170 ,  172  and their respective saddles  190 ,  192 , locking the distal portion  152  and the proximal portion  154  of the hub  150  to each other. Additionally, the projections  198 ,  200  are disposed within their respective recesses  174 ,  176  on the locking members  164 ,  166 , respectively, further securing the distal portion  152  to the proximal portion  154 .  
         [0037]    The catheter assembly  100  is secured to the patient by suturing the suture wing  178  to the patient&#39;s skin. The catheter  100  is now fully assembled and the luer locks  114  are ready to be connected to an outside machine, such as a dialysis machine (not shown).  
         [0038]    If, after the distal portion  102  of the catheter assembly  100  has been inserted into the patient, and a portion of the catheter assembly  100 , such as, for example, a luer lock  114  which may have broken, is required to be replaced, the hub  150  may be disassembled, and the proximal end  104  of the catheter assembly  100  may be replaced, without having to remove the catheter lumens  106 ,  108  from the patient.  
         [0039]    A hub disassembly tool  210 , shown in perspective in FIG. 8, may be used to unlock the locking members  174 ,  176  from the proximal end  154  of the hub  150 . A blade end  212  of the tool  210  is serially inserted between the proximal ends of each locking member  174 ,  176  and the proximal end  154  of the hub  150 . The tool  210  operates as a lever to assist a medical technician in unlocking the locking members  174 ,  176  from the proximal end  154  of the hub  150 .  
         [0040]    After the locking members  174 ,  176  are unlocked from the proximal end  154  of the hub  150  and rotated to displace the cams  170 ,  172  from their respective saddles  190 ,  192 , the distal hub portion  152  is separated from the proximal hub portion  154 , and the compression ring  202  is slid distally along the catheter lumens  106 ,  108 . The hub cannulae  186 ,  188  are now removed from their respective catheter lumens  106 ,  108 . Replacement pieces are now utilized in the place of broken pieces or pieces that otherwise may need to be replaced, and the catheter is reassembled as described above.  
         [0041]    It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.