Abstract:
Disclosed is a dual lumen retrograde catheter and hub attachment for dialysis. The catheter includes a venous lumen and an arterial lumen that are attached to a proximal hub having at least one luer extension extending therefrom. The distal end of the catheter is configured to be inserted into the blood vessel and placed into a desired position. The proximal end is tunneled backwards under the skin using a trocar and exited. The proximal end of the catheter can attach to a proximal hub via a pair of cannulas with raised barbs for removably securing proximal ends of the lumens thereon. The lumens are secured in a side-by-side configuration via a compression cap that can be screwed onto the proximal hub to prevent the catheter from detaching from the proximal hub.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 62/257,765, filed Nov. 20, 2015, which is hereby incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to a medical device. More particularly, the present invention is directed to a dual lumen retrograde catheter for a dialysis treatment and method of connecting the proximal end of the catheter to proximal molded tensions. 
       BACKGROUND OF THE INVENTION 
       [0003]    A dual lumen dialysis catheter generally comprises a distal end, a proximal end, and an integral longitudinal dual lumen tube that connects both of the ends to provide a conduit for moving blood or fluid to and from the body. These catheters are widely used in a routine dialysis procedure. The standard procedure typically requires a surgeon to tunnel the catheter under the skin and then secure the proximal hub in place before inserting the distal d into the blood vessel. 
         [0004]    This standard procedure is disadvantageous, however, in that the distal end is rarely placed in an ideal position. Additionally, it is difficult to adjust the tip of the catheter once the hub is already anchored in place. With a conventional retrograde procedure, the distal end of the lumen is tunneled first and placed into position, and then the proximal end is tunneled backwards under the skin and exited over the clavicle. 
         [0005]    While the backward tunneling improves the positioning of the distal end of the lumen, it does not allow for use of an integral proximal hub because it is impossible to maneuver the proximal end with a proximal hub integral thereto. In this regard, the invention described herein addresses this problem by providing a separate proximal hub and luer extensions that can removably attach to proximal ends of venous and arterial lumens to provide connections to blood lines once the proximal ends of the lumens exit the skin. 
       SUMMARY OF THE INVENTION 
       [0006]    In view of the disadvantages inherent in the known types of catheters and hub attachments now present in the prior art, the present invention provides an improved dual lumen catheter and hub attachment. 
         [0007]    The following discloses a simplified summary of the specification in order to provide a basic understanding of some aspects of the specification. This summary is not an extensive overview of the specification. It is intended to neither identify key or critical elements of the specification nor delineate the scope of the specification. Its sole purpose is to disclose some concepts of the specification in a simplified form as to prelude to the more detailed description that is disclosed later. 
         [0008]    In some embodiments, the present invention comprises a dual lumen retrograde catheter comprising a first D-shaped cannula and a second D-shaped cannula, each of the cannulas having a proximal end and a distal end. The catheter comprises various distal configurations, depending upon the embodiment. In some embodiments, the distal end of the catheter comprises a short term step tip. In some embodiments, the distal end of the catheter comprises a retrograde long term step tip. In some embodiments, the distal end of the catheter comprises a retrograde long term split tip. In some embodiments, the distal end of the catheter comprises a long term split tip over wire implants. In some embodiments, the distal end of the catheter comprises a symmetrical split tip. 
         [0009]    The proximal ends of the first and second cannula are joined via a compression cap. The compression cap is adapted to secure the proximal ends of the first and second cannula to a proximal hub when the proximal ends of the cannulas mate with respective barbed cannulas extending from the proximal hub. In one embodiment, the compression cap can be secured in place by mating threaded elements disposed on the interior wall thereof with complementary threaded elements disposed on the proximal hub. 
         [0010]    The proximal hub establishes fluid communication between the dual lumen retrograde catheter and luer extensions. In some embodiments, the proximal hub is connected to a first luer extension and a second luer extension, each of the luer extensions connected to a female luer for blood line connection to provide a conduit for blood or fluid to and from the body. In some embodiments, each of the luer extensions further comprises a pinch clamp thereon. 
         [0011]    In use, a distal end of the catheter is inserted into the blood vessel and placed into position, and then the proximal end of the catheter is tunneled backwards under the skin using a trocar and exited over the clavicle. Once the proximal end of the catheter exits the skin, the proximal hub with the barbs is attached to the lumens to provide connections to the bloodlines. A compression cap is then threaded over the barb connection site and screwed onto the proximal hub to prevent the catheter from easily detaching. 
         [0012]    It is, therefore, an objective of the present invention to provide a new and improved hub attachment that can be used with a retrograde catheter having any distal configuration in a retrograde catheterization procedure. 
         [0013]    It is another objective of the present invention to provide a connection of the proximal extension cannula to a catheter after backward tunneling is completed in a retrograde catheterization procedure. 
         [0014]    It is still another objective of the present invention to provide a new and improved dual lumen retrograde catheter and hub attachment that increases the ease and convenience of a retrograde catheterization procedure. 
         [0015]    It is still yet another objective of the present invention to provide a new and improved dual lumen retrograde catheter and hub attachment that improves the positioning of the distal end of the catheter during a retrograde catheterization procedure. 
         [0016]    A final objective of the present invention to provide a new and improved dual lumen retrograde catheter and hub attachment that may be readily fabricated from materials that permit relative economy and commensurate with durability. 
         [0017]    In the light of the foregoing, these and other objectives are accomplished in accordance with the principles of the present invention, wherein the novelty of the present invention will become apparent from the following detailed description and appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The above and other objects and advantages of the present invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying exemplary drawings, in which like reference characters refer to like parts throughout, and in which: 
           [0019]      FIG. 1  shows a top elevational view of the proximal end of the present invention. 
           [0020]      FIG. 2  shows a view of the distal end of a short term step tip catheter. 
           [0021]      FIG. 3  shows a view of the distal end of a long term split tip. 
           [0022]      FIG. 4  shows a view of the distal end of a symmetrical split tip. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    The present invention is directed towards a catheter and hub attachment. For purposes of clarity, and not by way of limitation, illustrative views of the present invention are described with references made to the above-identified figures. Various modifications obvious to one skilled in the art are deemed to be within the spirit and scope of the present invention. 
         [0024]    Moreover, the word “exemplary” is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word exemplary is intended to disclose concepts in a concrete fashion. As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” 
         [0025]    Additionally, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” or “at least one” unless specified otherwise or clear from context to be directed to a singular form. Similarly, the terms “plurality” and “a plurality” as used herein includes, for example, “multiple” or “two or more.” For example, “a plurality of items” includes two or more items. 
         [0026]    Referring now to  FIG. 1 , there is shown a view of the present invention in a disconnected configuration. The present invention comprises a dual lumen catheter and hub attachment  100 . In some embodiments, the first lumen  114  comprises a venous lumen and the second lumen  113  comprises an arterial lumen. Preferably, the walls of the lumens  113 ,  114  comprise sufficient thickness in order to prevent kinking during storage, transport, and use. 
         [0027]    Each of the venous lumen  114  and the arterial lumen  113  comprises a tube with a D-shape or a semi-circular cross section. In this way, the cross section of the venous lumen  114  and the arterial lumen  113  as joined together side-by-side form a substantially circular shape. Thus, the diameter of the cross sections of the venous lumen  114  and the arterial lumen  113  are substantially equal. 
         [0028]    Each of the venous lumen  114  and the arterial lumen  113  comprises a proximal end  115 ,  111  and a distal end (exemplary embodiments shown in  FIGS. 2 and 3 ), the distance between the proximal end  115 ,  111  and the distal end of each of the lumens  114 ,  113  defining a length of respective lumens  114 ,  113 . In some embodiments, the length of the venous lumen  114  is greater than the length of the arterial lumen  113 . The proximal ends  111 ,  115  of the lumens  113 ,  114  are aligned together and held in place via a compression cap  112 . Thus, the distal end of the venous lumen  114  extends beyond the distal end of the arterial lumen  113 . Alternatively, the length of the venous lumen  114  and the arterial lumen  113  are substantially equal. In this regard, the lumens need not be specifically designated as a venous lumen or an arterial lumen, and the connection can be reversed without high recirculation if one lumen is blocked. 
         [0029]    The proximal ends  115 ,  111  of the lumens  113 ,  114  removably connect to a proximal hub  107 . The proximal hub  107  comprises a first end  117  and a second end  116 , the first end  117  comprising luer extensions  117 ,  122  extending therefrom, and the second end  116  comprising a first  110  and second cannula  123  with raised barbs extending therefrom. The cannulas  110 ,  123  comprise a substantially tubular structure. One terminal end of the cannulas  110 ,  123  is integral to the second end  116  of the proximal hub  107 , and the opposing terminal end of the cannulas  110 ,  123  is free. In the illustrated embodiment, the proximal hub  107  tapers toward the second end  116  thereof. 
         [0030]    Each of the first  110  and second cannulas  123  is in fluid communication with a first luer extension  103  and a second luer extension  101 , respectively. In this regard, the proximal hub  107  comprises a pair of tunnels  122 , each tunnel acting as a conduit for the cannulas  110 ,  123  and the luer extensions  103 ,  101 . The tunnels  122  span the distance between the free terminal end of the cannulas  110 ,  123  to the first end  117  of the proximal hub  107 . Additionally, the illustrated embodiment of the proximal hub  107  comprises suture holes  108  on opposing sides thereof. 
         [0031]    Each of the first  110  and second cannula  123  is shaped and dimensioned to mate with the proximal ends  115 ,  111  of the venous lumen  114  and the arterial lumen  113 , respectively. More specifically, the free terminal ends of the cannulas  110 ,  123  can be inserted into the proximal ends  115 ,  111  of the venous lumen  114  and the arterial lumen  113 . Accordingly, the diameter of the cross section of the cannulas  110 ,  123  is less than the diameter of the cross section of the lumens  114 ,  113 . 
         [0032]    When the cannulas  110 ,  123  connect to the lumens  114 ,  113 , the barbs facilitate in providing connections to bloodlines by preventing the lumens  114 ,  113  from easily or inadvertently separating from the cannulas  110 ,  123 . It is contemplated that the barbs are configured to allow the lumens  114 ,  113  and the cannulas  110 ,  123  to connect relatively easily while improving separation force. 
         [0033]    The proximal ends  115 ,  111  of the lumens  114 ,  113  are joined together via the compression cap  112 . Optionally, the exterior of the compression cap comprises an identification cap for labeling. The interior of the compression cap  112  (i.e., near the end facing the proximal ends  115 ,  111 ) comprises threaded elements. 
         [0034]    When the cannulas  110 ,  123  removably connect to the lumens  114 ,  113 , the compression cap  112  can be placed over the connection site so that the threaded elements disposed within the interior of the compression cap  112  can engage complementary threaded elements  109  disposed on the second end  116  of the proximal hub  107 . More specifically, the complementary threaded elements  109  are disposed near the base of the cannulas  110 ,  123 . In this way, the compression cap  112  can removably attach to the proximal hub  107  in a screw-like manner and the compression cap  112  acts as a reinforcement feature for preventing the lumens  114 ,  113  from disengaging unintentionally. 
         [0035]    Each of the first and second luer extensions  103 ,  101  comprises a distal end  118 ,  119  and a proximal end  121 ,  120 . In some embodiments, the proximal hub  107  is molded to the proximal ends  118 ,  119  of the luer extensions  103 ,  101  so that it remains secured thereto and prevents leaking of fluids or other materials. Each of the proximal ends  121 ,  120  of the luer extensions  103 ,  101  comprises a female luer  106 ,  105  thereon for blood line connection. Additionally, the luer extensions  103 ,  101  comprise a clamp  104 ,  102  attached thereto. In the illustrated embodiment, the clamps  104 ,  102  comprise a pinch clamp. 
         [0036]    In some embodiments, each clamp  104 ,  102  comprises a tag integral thereto. In this regard, each of the clamps can comprise a recessed portion for receiving the tag therein. The tag is shaped and dimensioned to fit snugly within the recessed portion. In this way, the tag is secured within the recessed portion via snap means or other fastening means. The outer surface of the tag comprises a printed label thereon. In some embodiments, the outer surface of the proximal hub may also comprise a printed label thereon. 
         [0037]    Referring now to  FIG. 2 , there is shown a view of the distal end of a short term step tip catheter  200 . The catheter comprises a venous lumen  114 A and an arterial lumen  113 A. The distal end  130 A of the venous lumen  114 A extend beyond the distal end  132 A of the arterial lumen  113 A. The distal end  130 A of the venous lumen  114 A comprises a pointed tip  131 A. Each of the venous lumen  114 A and the arterial lumen  113 A comprises a D-shaped cross section so as to form a complete circular cross section when positioned together. The short term dialysis catheter can comprise D-shaped obturators in both lumens, depending upon the embodiment. The obturator can be configured to fit through the hub. It is contemplated that in other embodiments, the present invention may comprise a retrograde long term step tip, which is substantially equal to the short term step tip without an obturator. 
         [0038]    Referring now to  FIG. 3 , there is shown a view of the distal end of a long term split tip  300 . The catheter comprises a venous lumen  114 B and an arterial lumen  113 B. The distal end  130 B of the venous lumen  114 B extend beyond the distal end  132 B of the arterial lumen  113 B. The distal end  130 B of the venous lumen  114 B comprises a pointed tip  131 B. The venous lumen  114 B and the arterial lumen  113 B are split at the distal ends  130 B,  132 B thereof. Each of the venous lumen  114 B and the arterial lumen  113 B comprises a D-shaped cross section so as to form a complete circular cross section when positioned together. In some embodiments, the venous lumen  114 B and the arterial lumen  113 B are held together within a sleeve  133  in order to accommodate lumens of different sizes (i.e., different cross section diameters). 
         [0039]    In some embodiments, the venous lumen  114 B may comprise a slit for receiving an obturator is inserted through, thereby allowing the obturator to transition from the arterial lumen  113 B to the venous lumen  114 B. 
         [0040]    Referring now to  FIG. 4 , there is shown a distal end of a symmetrical split tip catheter  400 . The catheter comprises a first lumen  114 C and a second lumen  113 C, wherein the two lumens are substantially symmetrical and are joined together and split at the distal ends  132 C,  130 C thereof. The cross section of the catheter  400  is substantially circular, and the lumens  114 C,  113 C are separated via a septum  136 . 
         [0041]    The distal ends  132 C,  130 C are bent apart from each other such that the catheter resembles a Y-shape when viewed from the front. Additionally, each of the distal ends  132 C,  130 C comprises a U-shaped slot  135  to prevent the inflow of blood from becoming blocked. Because the lumens  114 C,  113 C are not specifically designated as a venous lumen or an arterial lumen, the connection can be reversed without high recirculation if one of the lumens is blocked. 
         [0042]    It is therefore submitted that the instant invention has been shown and described in what is considered to be the most practical and preferred embodiments. It is recognized, however, that departures may be made within the scope of the invention and that obvious modifications will occur to a person skilled in the art. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. 
         [0043]    Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.