Patent Publication Number: US-7211074-B2

Title: Valved catheter

Description:
BACKGROUND 
   1. Technical Field 
   The present disclosure generally relates to medical catheter apparatus and, more particularly, to a multiple lumen catheter apparatus that facilitates bi-directional fluid flow. 
   2. Description of the Related Art 
   Some known catheters are tubular, flexible medical devices for administration of fluids (withdrawal, introduction, etc.) with cavities, ducts, vessels, etc. of a body. Typically, catheter devices are inserted with the cavity of a body via a sheath, stylet, trocar, etc. 
   These catheter devices may be employed for administration of fluids that includes the simultaneous introduction and withdrawal of fluid for applications such as, surgery, treatment, diagnosis, etc. For example, in one particular hemodialysis application, blood is withdrawn from a blood vessel for treatment by an artificial kidney device and the treated blood is introduced back into the blood vessel. Various known catheter devices have been employed for simultaneous withdrawal and introduction of fluid with a body. Some devices use two separate needles or catheters. These devices, however, require two separate punctures with the associated discomfort, possibility for infection, and consequent trauma to the blood vessels. Other devices employ dual lumen catheters to facilitate bi-directional fluid flow whereby one lumen performs withdrawal of blood and the other lumen introduces treated blood to the vessel. 
   The above mentioned catheter devices, however, typically require clamping of the tubular portions or lumens when fluid administration is not being performed. This type of structure can result in several drawbacks. For example, blood can remain in the lumen causing thrombosis in the line and/or at the tip of the device. This results in a flow restriction that can significantly reduce flow rate. Further, the clamps of these catheter devices may fail and/or may cause damage or deformation to the extension lines, particularly in those devices employed for extended periods of use, such as chronic catheters. Failure may result in undesirable blood evacuation, heparin leakage, etc. Moreover, devices employing clamps are generally bulky and cumbersome. 
   Therefore, it would be desirable to overcome the disadvantages and drawbacks of the prior art with a catheter apparatus that facilitates bi-directional fluid flow by employing a multiple lumen body having a valve configuration that prevents thrombosis. It would be desirable if such a catheter apparatus included a multiple valve configuration that prevents undesirable blood evacuation and anti-coagulant leakage. It would be highly desirable if the catheter apparatus had a smaller relative design to achieve the principles of the present disclosure. It is contemplated that the catheter apparatus and its constituent parts are easily and efficiently manufactured and assembled. 
   SUMMARY 
   Accordingly, a catheter apparatus is provided that facilitates bi-directional fluid flow by employing a multiple lumen body having a valve configuration that prevents thrombosis and may break up fibrin sheath to overcome the disadvantages and drawbacks of the prior art. Desirably, such a catheter apparatus includes a multiple valve configuration that prevents blood evacuation and anti-coagulant leakage. Most desirably the catheter apparatus has a smaller relative design to achieve the principles of the present disclosure. The catheter apparatus is easily and efficiently manufactured and assembled. The present disclosure resolves related disadvantages and drawbacks experienced in the art. 
   In one particular embodiment, a dialysis catheter is provided with a tip that moves in and out of the catheter, to expose an arterial lumen and a venous lumen, for use and sealing when not in use. The motion of the tip results from attaching a blood line to the device whereby a male luer fitting pushes on a push rod of the device, as will be discussed. 
   Some of the advantages of the catheter device of the present disclosure include the arterial and/or venous lumens being sealed from blood contact when not in use. This configuration minimizes thrombosis and heparin leakage. Further, when the catheter device is not being employed, clamps are not required to prevent leakage. Thus, blood evacuation risk is minimized. 
   In another embodiment, the catheter device of the present disclosure includes a dual lumen catheter used for transdermal catheter related procedures, including hemodialysis. Upon attachment of appropriate blood lines, the device includes a normally closed arterial lumen that can be opened at the tip of the device to allow blood flow into the device. A normally closed valve within the hub of the device, including a luer fitting, can be opened to allow blood flow. The venous lumen may be similarly actuated. It is contemplated that the venous lumen is normally open at the tip of the device. 
   Other advantages of the catheter device include a reduced size that results in increased subject comfort. The tip of the catheter device allows for aspiration through an angle of 360 degrees. This facilitates a plurality of orientations and prevents positional occlusion. The tip of the device is axially movable relative to the lumens thereby disrupting fibrin sheath formation. 
   In one particular embodiment, the catheter apparatus includes a tubular body having a distal end. The body defines a first lumen and a second lumen. The first lumen includes a first adapter extending to a proximal end thereof. The first adapter includes a first valve biased to seal the proximal end. The first lumen defines a first lateral port and the second lumen defines a second lateral port adjacent the distal end of the body. A push rod is connected to the first valve for corresponding movement therewith and extends to a tip disposed adjacent the distal end of the body. The tip includes a first member extending into the first lumen and a second member extending into the second lumen such that the first member seals the first lateral port and the second member seals the second lateral port in a closed position of the tip. The first valve is engageable such that fluid communication is established between the proximal end of the first lumen and the first lumen, and the push rod causes the first and second members to move to an open position of the tip whereby fluid communication is established between the first lateral port and the first lumen, and the second lateral port and the second lumen. 
   The first lumen and the second lumen may be disposed in a substantially parallel orientation along at least a portion of the body. The first lumen may be configured for fluid flow in a first direction and the second lumen may be configured for fluid flow in a second opposite direction. The first lumen may be configured for venous blood flow and the second lumen may be configured for arterial blood flow. Each of the first lumen and the second lumen can have a substantially D-shaped configuration. The push rod is slidably mounted within the body and disposed between the first lumen and the second lumen. A portion of the push rod may be coaxially mounted with the first adapter. 
   The tip can include a pointed distal head. The tip may include a reverse umbrella valve that includes the first and second members such that the first and second members are slidable within the first and second lumens, respectively. Movement of the tip can cause the first member to move out of alignment with the first lateral port and the second member to move out of alignment with the second lateral port. 
   A luer fitting may be mounted with the proximal end of the first lumen. The luer fitting has a pusher that is connected with the first valve. A luer fitting may be mounted with the proximal end of the second lumen. The luer fitting has a pusher that is connected with the second valve. The proximal end of the first lumen may be configured for attachment to a fluid line for introduction of fluid into the first lumen and the first lateral port may be configured for expulsion of the fluid. The second lateral port may be configured for introduction of fluid into the second lumen and a proximal end of the second lumen may be configured for expulsion of the fluid to a receiving fluid line. 
   In an alternate embodiment, the first adapter defines a valve housing that supports the first valve and a spring that biases the first valve to seal the proximal end. The second lumen may include a second adapter extending to a proximal end thereof. The second adapter may include a second valve biased to seal the proximal end of the second lumen. The second adapter may define a valve housing that supports the second valve and a spring that biases the second valve to seal the proximal end. 
   The body desirably includes a valve configuration for simultaneously establishing fluid communication between the proximal end of the first lumen and the first lumen, and between the first lateral port and the first lumen, and between the second lateral port and the second lumen. 
   In another alternate embodiment, the catheter apparatus includes a tubular body having a distal end. The body defines a first lumen and a second lumen in a substantially coaxial orientation along at least a portion of the body. The first lumen includes a first adapter extending to a proximal end thereof. The first adapter has a first valve biased to seal the proximal end. The first lumen defines a first port and the second lumen defines a second port adjacent the distal end of the body. The first lumen has a portion that is connected to the first valve for corresponding movement therewith and the first lumen extends to the first port such that the first port seals the second port in a closed position thereof. The first valve is engageable such that fluid communication is established between the proximal end of the first lumen and the first lumen, such engagement further causing the first port to move to an open position whereby fluid communication is established between the second port and the second lumen. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The objects and features of the present disclosure, which are believed to be novel, are set forth with particularity in the appended claims. The present disclosure, both as to its organization and manner of operation, together with further objectives and advantages, may be best understood by reference to the following description, taken in connection with the accompanying drawings, as set forth below. 
       FIG. 1  is a perspective view of a catheter apparatus, in accordance with the principles of the present disclosure; 
       FIG. 2  is a top view of the catheter apparatus shown in  FIG. 1 ; 
       FIG. 3  is a side cross-sectional view, in part elevation, of the catheter apparatus in a closed position taken along line A—A of  FIG. 2 ; 
       FIG. 3A  is a cross-sectional view of the catheter apparatus taken along line B—B of  FIG. 2 ; 
       FIG. 4  is an a side cross-sectional view, in part elevation, of the catheter apparatus in an open position taken along line A—A of  FIG. 2 ; 
       FIG. 5  is an enlarged perspective cutaway view of a proximal end of the catheter apparatus; 
       FIG. 6  is a perspective half-section view of the proximal end shown in  FIG. 5  in a sealed configuration; 
       FIG. 7  is a perspective half-section view of the proximal end shown in  FIG. 5  in a non-sealed configuration; 
       FIG. 8  is a perspective view of an alternate embodiment of the catheter apparatus, in accordance with the principles of the present disclosure; 
       FIG. 9  is a top perspective view of the catheter apparatus shown in  FIG. 8 ; 
       FIG. 10  is a side view of the catheter apparatus shown in  FIG. 8 ; 
       FIG. 11  is a front view of the catheter apparatus shown in  FIG. 8 ; 
       FIG. 12  is an enlarged perspective half section view of the catheter apparatus shown in  FIG. 8 , in a closed position; 
       FIG. 13  is an enlarged perspective half section view of the catheter apparatus shown in  FIG. 8 , in an open position; 
       FIG. 14  is a perspective view of another alternate embodiment of the catheter apparatus, in accordance with the principles of the present disclosure; 
       FIG. 15  is a front view of the catheter apparatus shown in  FIG. 14 ; 
       FIG. 16  is a top view of the catheter apparatus shown in  FIG. 14 ; 
       FIG. 17  is a side cross-sectional view, taken along line A—A of  FIG. 16 , of the catheter apparatus; and 
       FIG. 18  is an enlarged perspective half section view of the portion of the catheter apparatus shown in  FIG. 14 . 
   

   DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
   The exemplary embodiments of the catheter apparatus and methods of use disclosed are discussed in terms of medical catheters for the administration of fluids (withdrawal, introduction, etc.) with the body of a subject and more particularly, in terms of a catheter apparatus that facilitates bidirectional fluid flow by employing a multiple lumen body having a valve configuration that prevents thrombosis and fibrin sheath formation. It is envisioned that the present disclosure may be employed with a range of catheter applications including surgical, diagnostic and related treatments of diseases, body ailments, etc. of a subject. It is further envisioned that the principles relating to the catheter apparatus disclosed include employment with various catheter related procedures, such as, for example, hemodialysis, cardiac, abdominal, urinary, intestinal, etc., in chronic, acute, etc. applications. It is contemplated that the catheter apparatus can be used for administration of fluids such as, for example, medication, saline, bodily fluids such as, blood, urine, etc. 
   In the discussion that follows, the term “proximal” will refer to the portion of a structure that is closer to a practitioner, while the term “distal” will refer to the portion that is further from the practitioner. As used herein, the term “subject” refers to a human patient or other animal. According to the present disclosure, the term “practitioner” refers to a doctor, nurse or other care provider and may include support personnel. 
   The following discussion includes a description of the catheter apparatus, followed by a description of an exemplary method of operating the catheter apparatus in accordance with the principles of the present disclosure. Reference will now be made in detail to the exemplary embodiments of the present disclosure, which are illustrated in the accompanying figures. Turning now to the figures wherein like components are designated by like reference numerals throughout the several views and initially to  FIGS. 1 and 2 , there is illustrated a catheter apparatus  20 , in accordance with the principles of the present disclosure. 
   The components of catheter apparatus  20  are fabricated from materials suitable for medical applications, such as, for example, polymerics or metals, such as stainless steel, depending on the particular catheter application and/or preference of a practitioner. Semi-rigid and rigid polymerics are contemplated for fabrication, as well as resilient materials, such as molded medical grade polypropylene. One skilled in the art, however, will realize that other materials and fabrication methods suitable for assembly and manufacture, in accordance with the present disclosure, also would be appropriate. 
   Catheter apparatus  20  includes a tubular body  22  having a distal end  24 . Tubular body  22  is elongated and has a cylindrical outer surface. It is contemplated that tubular body  22  may be variously dimensioned and attachable to other medical devices. It is further contemplated that the outer surface of tubular body  22  may have various configurations, such as, for example, rectangular, elliptical, polygonal, etc. 
   Referring to  FIGS. 3–8 , tubular body  22  defines a first lumen such as, for example, venous lumen  26  and a second lumen such as, for example, arterial lumen  28 . Venous lumen  26  and arterial lumen  28  each have a substantially D-shaped or semi-circular configuration. Venous lumen  26  includes an inner surface  27  having a substantially planar portion  27 A and a substantially arcuate portion  27 B, as shown in  FIG. 3A . Arterial lumen  28  includes an inner surface  29  having a substantially planar portion  29 A and a substantially arcuate portion  29 B. Lumens  26 ,  28  are elongated with tubular body  22  and inner surfaces  27 ,  29  are configured to facilitate fluid flow within lumens  26 ,  28 . It is envisioned that lumens  26 ,  28  may have various configurations, such as, for example, cylindrical, rectangular, elliptical, polygonal, etc. 
   Venous lumen  26  is configured for fluid flow, such as, for example, venous blood flow, in a first direction, as shown by arrows A. Arterial lumen  28  is configured for fluid flow, such as, for example, arterial blood flow in a second opposite direction, as shown by arrows B. The first and second lumens may be configured for various forms of fluid flow in various directions and orientations, according to the requirements of a particular catheter application. 
   Lumens  26 ,  28  may be uniformly dimensioned or include alternative dimensional cross sections within tubular body  22 , such as, narrow and broad portions, converging surfaces, undulating surfaces, etc. according to the particular flow indications and/or flow rate requirements. It is contemplated venous lumen  26  and arterial lumen  28  may extend alternative lengths. It is further contemplated that tubular body  22  may include one or a plurality of lumens. It is envisioned that the first lumen may include the arterial lumen and the second lumen may include the venous lumen. 
   Venous lumen  26  and arterial lumen  28  are disposed in a substantially parallel orientation adjacent a distal portion  30  of tubular body  22 . Distal portion  30  may extend various lengths and may include portions of tubular body  22  that are in a non-parallel orientation. It is also contemplated that venous lumen  26  and arterial lumen  28  may be spaced apart. 
   Venous lumen  26  includes a first adapter, such as, for example, tubular venous adapter  32  that extends to a proximal end  34  thereof. Venous adapter  32  defines a valve housing  36  adjacent proximal end  34 . Valve housing  36  has a cylindrical configuration to facilitate support of a first valve  38  and a spring  40  that biases first valve  38 , in a substantially proximal direction as shown by arrow C, to seal proximal end  34 . Spring  40  may be fixedly mounted to an inner surface of valve housing  36 . A first luer fitting  42  is mounted with proximal end  34 . First luer fitting  42  includes a first pusher  44  that is connected with first valve  38 . It is contemplated that first pusher  44  may be separately formed from first valve  38  and disposed for engagement therewith. 
   Spring  40  expands, via a spring force thereof, to engage first valve  38 , forcing first valve  38  in the direction shown by arrow C. As first valve  38  moves, a surface  46  of first valve  38  engages a surface  48  of proximal end  34 . This engagement creates a fluid tight seal between first valve  38  and proximal end  34 . The seal prevents inflow of fluids into venous lumen  26  and prevents leakage of fluids therefrom. First valve  38 , being connected to first pusher  44 , causes first pusher  44  to move in the direction shown by arrow C, and protrude from proximal end  34  for engagement with a venous blood line  50 , as will be discussed. It is contemplated that the attachment of venous blood line  50  with proximal end  34  is configured for introduction of fluid into venous lumen  26 . 
   First luer fitting  42  is configured for attachment to venous blood line  50 . Venous blood line  50  includes a pusher component  52  that engages first pusher  44  to facilitate fluid communication between venous blood line  50  and venous lumen  26 . Venous blood line  50  may be attached via luer connection, threaded connection, snap on, clips, etc. 
   Venous blood line  50  is attached to first luer fitting  42  such that pusher component  52  engages first pusher  44 , causing movement of first pusher  44  in a substantially distal direction, as shown by arrow D. The portion of first pusher  44  protruding from proximal end  34  is engaged by pusher component  52  as venous blood line  50  is attached to proximal end  34 . The movement of first pusher  44  causes first valve  38  to overcome the bias of spring  50  and allow movement of first valve  34  in the direction shown by arrow D. 
   Surface  46  of first valve  38  disengages from surface  48  of proximal end  34 . The fluid tight seal is interrupted, thereby opening proximal end  34  to establish fluid communication between proximal end  34  and venous lumen  26 . 
   Conversely, as venous blood line  50  is removed from proximal end  34 , pusher component  52  disengages from first pusher  44 . Spring  40  re-expands, forcing first valve  38  in the direction shown by arrow C. Surface  46  engages surface  48  to create the fluid tight seal between first valve  38  and proximal end  34 . It is contemplated that valve housing  36  may have various geometric configurations such as, rectangular, elliptical, polygonal, etc. It is further contemplated that spring  40  may alternatively include resiliently biasing structure such as, a resilient arm, pneumatic, hydraulic, magnetic force, etc. and may be electronically or manually controlled. First valve  38  may be oriented to engage various portions of proximal end  34 . It is envisioned that first valve  38  may be monolithically formed or integrally connected to first pusher  44 , or may include other valve structure, such as, slit valves, threaded, umbrella valves, diaphragm valves, etc. 
   Venous lumen  26  includes a first lateral port  54  disposed adjacent distal end  24  of tubular body  22 . First lateral port  54  includes an opening  55  that is configured for fluid flow. First lateral port  54  may be variously dimensioned and configured, such as, for example, rectangular, elliptical, polygonal, etc. Opening  55  is defined by the thickness of a wall portion  56  of tubular body  22  adjacent thereto. First lateral port  54  may include adapters, clips, etc. to facilitate fluid flow and/or attachment to other structure. It is contemplated that first lateral port  54  is configured for expulsion of fluid from venous lumen  26 . 
   Arterial lumen  28  includes a first adapter, such as, for example, tubular arterial adapter  58  that extends to a proximal end  60  thereof. Arterial adapter  58  defines a valve housing  62  adjacent proximal end  60 . Valve housing  62  has a cylindrical configuration to facilitate support of a second valve  64  and a spring  66  that biases second valve  64 , in a substantially proximal direction as shown by arrow E, to seal proximal end  60 . Spring  66  may be fixedly mounted to an inner surface of valve housing  62 . A second luer fitting  68  is mounted with proximal end  60 . Second luer fitting  68  includes a second pusher  70  that is connected with second valve  64 . 
   It is contemplated that second pusher  70  may be separately formed from second valve  64  and disposed for engagement therewith. It is further contemplated that proximal end  60  is configured for expulsion of fluid to a receiving fluid line. It is envisioned that one or both of lumens  26 ,  28  may include no adapters, one or a plurality of adapters, such as, for example, an embodiment whereby venous lumen  26  has a valved adapter and arterial lumen  28  does not have a valved adapter. 
   Spring  66  expands, via a spring force thereof, to engage second valve  64 , forcing second valve  64  in the direction shown by arrow E. As second valve  64  moves, a surface  72  of second valve  64  engages a surface  74  of proximal end  60 . This engagement creates a fluid tight seal between second valve  64  and proximal end  60 . The seal prevents inflow of fluids into arterial lumen  28  and prevents leakage of fluids therefrom. Second valve  64 , being connected to second pusher  70 , causes second pusher  70  to move in the direction shown by arrow E, and protrude from proximal end  60  for engagement with an arterial blood line  76 , as will be discussed. 
   Second luer fitting  68  is configured for attachment to arterial blood line  76 . Arterial blood line  76  includes a pusher component  78  that engages second pusher  70  to facilitate fluid communication between arterial blood line  76  and arterial lumen  26 . Arterial blood line  76  may be attached via luer connection, threaded connection, snap on, clips, etc. 
   Arterial blood line  76  is attached to second luer fitting  68  such that pusher component  78  engages second pusher  70 , causing movement of second pusher  70  in a substantially distal direction, as shown by arrow F. The portion of second pusher  70  protruding from proximal end  60  is engaged by pusher component  70  as arterial blood line  76  is attached to proximal end  60 . The movement of second pusher  70  causes second valve  64  to overcome the bias of spring  66  and allow movement of second valve  64  in the direction shown by arrow F. 
   Surface  72  of second valve  64  disengages from surface  74  of proximal end  60 . The fluid tight seal is interrupted, thereby opening proximal end  60  to establish fluid communication between proximal end  60  and arterial lumen  28 . 
   Conversely, as arterial blood line  76  is removed from proximal end  60 , pusher component  78  disengages from second pusher  70 . Spring  66  re-expands, forcing second valve  64  in the direction shown by arrow E. Surface  72  engages surface  74  to create the fluid tight seal between second valve  64  and proximal end  60 . It is contemplated that valve housing  62  may have various geometric configurations such as, rectangular, elliptical, polygonal, etc. It is further contemplated that spring  66  may alternatively include resiliently biasing structure such as, a resilient arm, pneumatic, hydraulic, magnetic force, etc. and may be electronically or manually controlled. Second valve  64  may be oriented to engage various portions of proximal end  60 . It is envisioned that second valve  64  may be monolithically formed or integrally connected to second pusher  70 , or may include other valve structure, such as, slit valves, threaded, umbrella valves, diaphragm valves, etc. 
   Arterial lumen  28  includes a second lateral port  80  disposed adjacent distal end  24  of tubular body  22 . Second lateral port  80  includes an opening  82  that is configured for fluid flow. Opening  82  may be variously dimensioned and configured, such as, for example, rectangular, elliptical, polygonal, etc. Opening  82  is defined by the thickness of a wall portion  84  of tubular body  22  adjacent thereto. Second lateral port  80  may include adapters, clips, etc. to facilitate fluid flow and/or attachment to other structure. It is contemplated that second lateral port  80  is configured for introduction of fluid into arterial lumen  28 . 
   A push rod  88  is connected to first valve  38  within valve housing  36 . Push rod  88  is slidably supported by a central lumen  90  ( FIG. 3A ) of tubular body  22  and extends to a pointed distal tip  92  disposed adjacent distal end  24 . Central lumen  90  is disposed between venous lumen  26  and arterial lumen  28 , and extends to distal end  24 . Push rod  88  is mounted with central lumen  90  such that the portion of push rod  88  disposed with venous adapter  32  is coaxially mounted therewith. 
   Push rod  88  is associated with first valve  38  for corresponding slidable movement therewith. For example, as first valve  38  is forced proximally in the direction shown by arrow C, discussed above, push rod  88  is similarly forced in the direction shown by arrow C. Further, as first valve  38  is forced distally in the direction shown by arrow D, discussed above, push rod  88  is similarly forced in the direction shown by arrow D. Tip  92  is movable corresponding to the movement of first valve  38 , as facilitated by push rod  88 . The slidable movement of push rod  88  causes corresponding slidable movement of a valve  94  that includes tip  92 , as will be discussed. 
   Tip  92  has a proximal portion  96  and a distal portion  98 . Proximal portion  96  includes a first member  100  extending into venous lumen  26  and a second member  102  extending into arterial lumen  28 . First lateral port  54  is disposed proximally, with tubular body  22 , relative to second lateral port  80 . Thus, first member  100  extends a greater dimensional length than second member  102  to seal first lateral port  54  and second lateral port  80 , as will be discussed. 
   First member  100  extends, in a proximal direction, a greater depth within venous lumen  26  relative to the depth of extension of second member  102  within arterial lumen  28 . It is envisioned that second member  102  may extend a greater depth within lumens  26 ,  28  than first member  100 , or alternatively, first member  100  and second member  102  may extend the same depth. 
   First member  100  includes an arcuate portion  104  that conforms to the correspondingly configured arcuate portion  27 B of inner surface  27  of venous lumen  26 , adjacent first lateral port  54 . Arcuate portion  104  engages arcuate portion  27 B to facilitate slidable movement of first member  100  relative to venous lumen  26 . It is contemplated that arcuate portion  104  sealingly engages arcuate portion  27 B via interference using an O-ring type thin malleable surface, an umbrella type valve surface, etc. It is envisioned that first member  100  may have a D-shaped/semicircular cross-section, or may have a wall portion that includes arcuate portion  104 . 
   Second member  102  includes an arcuate portion  106  that conforms to the correspondingly configured arcuate portion  29 B of inner surface  29  of arterial lumen  28 , adjacent second lateral port  80 . Arcuate portion  106  engages arcuate portion  29 B to facilitate slidable movement of second member  102  relative to arterial lumen  28 . It is envisioned that arcuate position  106  sealingly engages arcuate portion  29 B via interference using an O-ring type thin malleable surface, an umbrella type valve surface, etc. It is contemplated that second member  102  may have a D-shaped/semicircular cross-section, or may have a wall portion that includes arcuate portion  106 . It is further contemplated that first member  100  and second member  102  may be monolithically formed with tip  92 , or alternatively, may be integrally assembled with tip  92  and fabricated from dissimilar materials. 
   Distal portion  98  of tip  92  includes a pointed distal head  99 . Distal head  99  facilitates disposal of tubular body  22  within a body vessel and may be employed with a guidewire, sheath, etc. It is envisioned that distal head  99  may be employed with a stylet, tunneler, trocar, etc. to tunnel tubular body  22  under the skin of a subject (not shown). It is contemplated that distal head  99  may be variously configured or, alternatively, distal portion  98  may include a blunt tip. It is contemplated that tip  92  allows for aspiration through an angle of 360 degrees. This configuration facilitates disposal of distal end  24  of tubular body  22  in a plurality of orientations and prevents positional occlusion. 
   As push rod  88  moves distally, as shown by arrow C, or proximally, as shown by arrow D, first member  100  and second member  102 , extending from tip  92 , similarly move in a distal direction and a proximal direction. Such movement facilitates corresponding movement of valve  94 , which includes tip  92 , between a closed position ( FIG. 3 ) and an open position ( FIG. 4 ). 
   In the closed position, tip  92  flushly engages distal end  24  of tubular body  22 . First member  100  extends a sufficient depth within venous lumen  26  such that arcuate portion  104  spans across first lateral port  54 . Arcuate portion  104  flushly engages first lateral port  54  and the adjacent portions of arcuate portion  27 B of venous lumen  26  to close off first lateral port  54  and create a fluid tight seal therewith. Similarly, second member  102  extends a sufficient depth within arterial lumen  28  such that arcuate portion  106  spans across second lateral port  80 . Arcuate portion  106  flushly engages second lateral port  80  and the adjacent portions of arcuate portion  29 B of arterial lumen  28  to close of second lateral port  80  and create a fluid tight seal therewith. 
   As push rod  88  moves in the distal direction, as shown by arrow D, first member  100  and second member  102  are caused to slidably move relative to venous lumen  26  and arterial lumen  28 , respectively. First member  100  slides out of alignment with first lateral port  54 . Second member  102  slides out of alignment with second lateral port  80 . 
   In the open position, first member  100  disengages from first lateral port  54  and the adjacent portions of arcuate portion  27 B of venous lumen  26  to interrupt and open the fluid tight seal of first lateral port  54 , thereby facilitating fluid communication between first lateral port  54  and venous lumen  26 . 
   Similarly, second member  102  disengages from second lateral port  80  and the adjacent portions of arcuate portion  29 B of arterial lumen  28  to interrupt and open the fluid tight seal of second lateral port  80 , thereby facilitating fluid communication between second lateral port  80  and arterial lumen  28 . 
   As push rod  88  is caused to move back in the proximal direction, as shown by arrow C, first member  100  and second member  102  are caused to slidably move relative to venous lumen  26  and arterial lumen  28 , respectively. First member  100  reseals first lateral port  54 , as discussed, and second member  102  reseals second lateral port  80 , as discussed, such that valve  94 , which includes tip  92 , is again disposed in the closed position. It is contemplated that valve  94 , including tip  92 , may be releasably locked or permanently fixed in the open position and/or the closed position via detents, clips, etc. mounted adjacent distal end  24 , adapters  32 ,  58  or along other portions of tubular body  22 . This configuration advantageously facilitates desirable fluid flow rates and may break up thrombus or fibrin sheath formation. Further, the structure and methods illustrated for achieving the principles of the present disclosure also advantageously prevent undesirable fluid evacuation to further prevent thrombus formation on an innersurface of tubular body  22 . 
   Referring to  FIGS. 3 and 4 , in use, a catheter apparatus  20 , similar to that described, is assembled, properly sterilized and otherwise prepared for storage, shipment and use in a hemodialysis procedure. A practitioner (not shown) manipulates distal end  24  of tubular body  22  such that pointed distal head  99  of tip  92  can enter a body cavity of a subject (not shown). Distal end  24  is inserted within a blood vessel of the subject. Catheter apparatus  20  is employed for administration of fluids that includes the simultaneous introduction of venous blood flow and withdrawal of arterial blood flow. Catheter apparatus  20  is inserted with the blood vessel of the subject such that blood is withdrawn, via arterial blood flow in a first direction, from the blood vessel for treatment by an artificial kidney device (not shown) and the treated blood is introduced back into the blood vessel, via venous blood flow in a second opposite direction. 
   Initially, valve  94 , which includes tip  92 , is in the closed position. First member  100  extends within venous lumen  26  such that arcuate portion  104  spans across first lateral port  54 . Arcuate portion  104  flushly engages first lateral port  54  and the adjacent portions of arcuate portion  27 B of venous lumen  26  to close off first lateral port  54  and create a fluid tight seal therewith. Similarly, second member  102  extends within arterial lumen  28  such that arcuate portion  106  spans across second lateral port  80 . Arcuate portion  106  flushly engages second lateral port  80  and the adjacent portions of arcuate portion  29 B of arterial lumen  28  to close of second lateral port  80  and create a fluid tight seal therewith. 
   Surface  46  of first valve  38  engages surface  48  of proximal end  34  to create a fluid tight seal between first valve  38  and proximal end  34 , as discussed. First pusher  44  protrudes from proximal end  34 . Surface  72  of second valve  64  engages surface  74  of proximal end  60  to create a fluid tight seal between second valve  64  and proximal end  60 . Second pusher  70  protrudes from proximal end  60 . 
   Venous blood line  50  is attached to first luer fitting  42  such that pusher component  52  engages first pusher  44 , causing movement of first pusher  44  in a substantially distal direction, as shown by arrow D, overcoming the bias of spring  50 . Surface  46  of first valve  38  disengages from surface  48  of proximal end  34  and the fluid tight seal is interrupted, thereby opening proximal end  34  to establish fluid communication between proximal end  34  and venous lumen  26 . Venous blood flow is introduced to catheter apparatus  20  through proximal end  34 . 
   Arterial blood line  76  is attached to second luer fitting  68  such that pusher component  78  engages second pusher  70 , causing movement of second pusher  70  in a substantially distal direction, as shown by arrow F, overcoming the bias of spring  66 . Surface  72  of second valve  64  disengages from surface  74  of proximal end  60  and the fluid tight seal is interrupted, thereby opening proximal end  60  to establish fluid communication between proximal end  60  and arterial lumen  28 . Arterial blood flow may be received by arterial blood line  76 . 
   As first valve  38  is forced distally in the direction shown by arrow D, discussed above, push rod  88  is similarly forced in the direction shown by arrow D. Valve  94 , which includes tip  92 , is movable corresponding to the movement of first valve  38 , as facilitated by push rod  88 . As push rod  88  moves in the distal direction, first member  100  and second member  102  are caused to slidably move relative to venous lumen  26  and arterial lumen  28 , respectively. First member  100  slides out of alignment with first lateral port  54 . Second member  102  slides out of alignment second lateral port  80 . 
   Valve  94 , which includes tip  92 , moves to the open position. First member  100  disengages from first lateral port  54  and the adjacent portions of arcuate portion  27 B of venous lumen  26  to interrupt and open the fluid tight seal of first lateral port  54 , thereby facilitating fluid communication between first lateral port  54  and venous lumen  26 . Thus, venous blood flow is introduced to the blood vessel of the subject via venous lumen  26 . Second member  102  disengages from second lateral port  80  and the adjacent portions of arcuate portion  29 B of arterial lumen  28  to interrupt and open the fluid tight seal of second lateral port  80 , thereby facilitating fluid communication between second lateral port  80  and arterial lumen  28 . Thus, arterial blood flow is withdrawn from the blood vessel and received by arterial lumen  28  for receipt by arterial blood line  76 . 
   In the event that the practitioner desires to discontinue administration of fluids with the subject, valve  94 , which includes tip  92 , may be returned to the closed position. Venous blood line  50  is removed from proximal end  34  to recreate the fluid tight seal between first valve  38  and proximal end  34 . Arterial blood line  76  is removed from proximal end  60  to recreate the fluid tight seal between second valve  64  and proximal end  60 . 
   Push rod  88  is caused to move back in the proximal direction, as shown by arrow C. First member  100  reseals first lateral port  54  and second member  102  reseals second lateral port  80  such that valve  94 , which includes tip  92 , is again disposed in the closed position. 
   Referring to  FIGS. 8–13 , an alternate embodiment of the present disclosure is shown that includes a catheter apparatus  220 . Catheter apparatus  220  includes a tubular body  222  having a distal end  224 . Tubular body  222  is elongated and has a cylindrical outer surface. 
   Tubular body  222  defines a first lumen such as, for example, venous lumen  226  and a second lumen such as, for example, arterial lumen  228 . Venous lumen  226  and arterial lumen  228  are in a substantially coaxial orientation, with a longitudinal axis x, along a distal portion  230  of tubular body  222 . Venous lumen  226  and arterial lumen  228  each have a substantially tubular configuration that facilitate fluid flow. It is envisioned that lumens  226 ,  228  may have various configurations, such as, for example, cylindrical, rectangular, elliptical, polygonal, etc. 
   Venous lumen  226  is configured for fluid flow, such as, for example, venous blood flow, in a first direction, as shown by arrows AA. Arterial lumen  228  is configured for fluid flow, such as, for example, arterial blood flow in a second opposite direction, as shown by arrows BB. The first and second lumens may be configured for various forms of fluid flow in various directions and orientations, according to the requirements of a particular catheter application. 
   Lumens  226 ,  228  may be uniformly dimensioned or include alternative dimensional cross sections within tubular body  222 , such as, narrow and broad portions, converging surfaces, undulating surfaces, etc. according to the particular flow indications and/or flow rate requirements. It is contemplated venous lumen  226  and arterial lumen  228  may extend alternative lengths. It is further contemplated that tubular body  222  may include one or a plurality of lumens. It is envisioned that the first lumen may include the arterial lumen and the second lumen may include the venous lumen. 
   Venous lumen  226  includes a first adapter, such as, for example, tubular venous adapter  232  that extends to a proximal end  234  thereof. Venous adapter  232  defines a valve housing  236  adjacent proximal end  234 . Valve housing  236  has a cylindrical configuration to facilitate support of a first valve  238  and a spring  240  that biases first valve  238 , in a substantially proximal direction as shown by arrow CC, to seal proximal end  234 . Spring  240  may be fixedly mounted to an inner surface of valve housing  236 . A first luer fitting  242  is mounted with proximal end  234 . First luer fitting  242  includes a first pusher  244  that is connected with first valve  238 . 
   Spring  240  expands, via a spring force thereof, to engage first valve  238 , forcing first valve  238  in the direction shown by arrow CC. As first valve  238  moves, a surface  246  of first valve  238  engages a surface  248  of proximal end  234 . This engagement creates a fluid tight seal between first valve  238  and proximal end  234 . The seal prevents inflow of fluids into venous lumen  226  and prevents leakage of fluids therefrom. First valve  238 , being connected to first pusher  244 , causes first pusher  244  to move in the direction shown by arrow CC, and protrude from proximal end  234  for engagement with a venous blood line  250 , as will be discussed. 
   First luer fitting  242  is configured for attachment to venous blood line  250 . Venous blood line  250  includes a pusher component  252  that engages first pusher  244  to facilitate fluid communication between venous blood line  250  and venous lumen  226 . 
   Venous blood line  250  is attached to first luer fitting  242  such that pusher component  252  engages first pusher  244 , causing movement of first pusher  244  in a substantially distal direction, as shown by arrow DD. The portion of first pusher  244  protruding from proximal end  234  is engaged by pusher component  252  as venous blood line  250  is attached to proximal end  234 . The movement of first pusher  244  causes first valve  238  to overcome the bias of spring  250  and allow movement of first valve  234  in the direction shown by arrow DD. 
   Surface  246  of first valve  238  disengages from surface  248  of proximal end  234 . The fluid tight seal is interrupted, thereby opening proximal end  234  to establish fluid communication between proximal end  234  and venous lumen  226 . Conversely, as venous blood line  250  is removed from proximal end  234 , pusher component  252  disengages from first pusher  244 . Spring  240  re-expands, forcing first valve  238  in the direction shown by arrow CC. Surface  246  engages surface  248  to create the fluid tight seal between first valve  238  and proximal end  234 . 
   Venous lumen  226  defines a first port  254  disposed adjacent distal end  224  of tubular body  222 . First port  254  includes an opening  255  that is configured for fluid flow. First port  254  may be variously dimensioned and configured, such as, for example, rectangular, elliptical, polygonal, etc. First port  254  may include adapters, clips, etc. to facilitate fluid flow and/or attachment to other structure. It is contemplated that first port  254  is configured for expulsion of fluid from venous lumen  226 . 
   Arterial lumen  228  includes a first adapter, such as, for example, tubular arterial adapter  258  that extends to a proximal end  260  thereof. Arterial adapter  258  defines a valve housing  262  adjacent proximal end  260 . Valve housing  262  has a cylindrical configuration to facilitate support of a second valve  264  and a spring  266  that biases second valve  264 , in a substantially proximal direction as shown by arrow EE, to seal proximal end  260 . Spring  266  may be fixedly mounted to an inner surface of valve housing  262 . A second luer fitting  268  is mounted with proximal end  260 . Second luer fitting  268  includes a second pusher  270  that is connected with second valve  264 . 
   Spring  266  expands, via a spring force thereof, to engage second valve  264 , forcing second valve  264  in the direction shown by arrow EE. As second valve  264  moves, a surface  272  of second valve  264  engages a surface  274  of proximal end  260 . This engagement creates a fluid tight seal between second valve  264  and proximal end  260 . The seal prevents inflow of fluids into arterial lumen  228  and prevents leakage of fluids therefrom. Second valve  264 , being connected to second pusher  270 , causes second pusher  270  to move in the direction shown by arrow EE, and protrude from proximal end  260  for engagement with an arterial blood line  276 , as will be discussed. Second luer fitting  268  is configured for attachment to arterial blood line  276 . Arterial blood line  276  includes a pusher component  278  that engages second pusher  270  to facilitate fluid communication between arterial blood line  276  and arterial lumen  226 . 
   Arterial blood line  276  is attached to second luer fitting  268  such that pusher component  278  engages second pusher  270 , causing movement of second pusher  270  in a substantially distal direction, as shown by arrow FF. The portion of second pusher  270  protruding from proximal end  260  is engaged by pusher component  270  as arterial blood line  276  is attached to proximal end  260 . The movement of second pusher  270  causes second valve  264  to overcome the bias of spring  266  and allow movement of second valve  264  in the direction shown by arrow FF. 
   Surface  272  of second valve  264  disengages from surface  274  of proximal end  260 . The fluid tight seal is interrupted, thereby opening proximal end  260  to establish fluid communication between proximal end  260  and arterial lumen  228 . Conversely, as arterial blood line  276  is removed from proximal end  260 , pusher component  278  disengages from second pusher  270 . Spring  266  re-expands, forcing second valve  264  in the direction shown by arrow EE. Surface  272  engages surface  274  to create the fluid tight seal between second valve  264  and proximal end  260 . 
   Arterial lumen  228  includes a second port  280  disposed adjacent distal end  224  of tubular body  222 . Second port  280  includes an opening  282  that is configured for fluid flow. Opening  282  may be variously dimensioned and configured, such as, for example, rectangular, elliptical, polygonal, etc. Second port  280  may include adapters, clips, etc. to facilitate fluid flow and/or attachment to other structure. It is contemplated that second port  280  is configured for introduction of fluid into arterial lumen  228 . 
   A portion of venous lumen  226 , such as, for example, push rod portion  288  is connected to first valve  238  within valve housing  236  for corresponding movement therewith. Push rod portion  288  is slidably mounted within tubular body  222  and extends to first port  254 . First port  254  seals second port  280  in a closed position of a valve configuration including first port  254  and second port  280 . 
   Push rod portion  288  is connected with first valve  238  for corresponding slidable movement therewith. Push rod portion  288  includes openings  289  that facilitate fluid communication between proximal end  234  and venous lumen  226 . Openings  289  may be variously configured such as, slots, vents, circular, polygonal, etc. Push rod portion  288  may be attached to first valve  238  by various means, such as, for example, adhesive, clips, etc., may be monolithic therewith, or spaced apart therefrom. 
   For example, as first valve  238  is forced proximally in the direction shown by arrow CC, discussed above, push rod portion  288  is similarly forced in the direction shown by arrow CC. Further, as first valve  238  is forced distally in the direction shown by arrow DD, discussed above, push rod portion  288  is similarly forced in the direction shown by arrow DD. First port  254  is movable corresponding to the movement of first valve  238 , as facilitated by push rod portion  288 . 
   As push rod portion  288  moves proximally, as shown by arrow CC, or distally, as shown by arrow DD, first port  254  similarly moves in a proximal direction and a distal direction. Such movement facilitates corresponding movement of the valve configuration that includes first port  254  and second port  280 , between a closed position ( FIG. 12 ) and an open position ( FIG. 13 ). 
   In the closed position, first port  254  engages second port  280  to close off second port  280  and create a fluid tight seal therewith. As push rod portion  288  moves in the distal direction, as shown by arrow DD, first port  254  is caused to slidably move relative to distal end  224  and second port  280 . In the open position, first port  254  disengages from second port  280  to interrupt and open the fluid tight seal of second port  280 , thereby facilitating fluid communication between second port  280  and arterial lumen  228 . 
   As push rod portion  288  is caused to move back in the proximal direction, as shown by arrow CC, first port  254  is caused to slidably move relative to distal end  224  and second port  280 . First port  254  reseals second port  280 , as discussed, such that the valve configuration that includes first port  254  and second port  280  is again disposed in the closed position. It is contemplated that the valve configuration that includes first port  254  and second port  280  may be releasably locked or permanently fixed in the open position and/or the closed position via detents, clips, etc. mounted adjacent distal end  224 , adapters  232 ,  258  or along other portions of tubular body  222 . This configuration advantageously facilitates desirable fluid flow rates and may prevent thrombosis and fibrin sheath formation. Further, the structure and methods illustrated for achieving the principles of the present disclosure also advantageously prevent undesirable fluid evacuation and enhance comfort to a subject. It is envisioned that one or both of lumens  226 ,  228  may include no adapters, one or a plurality of adapters, such as, for example, an embodiment whereby venous lumen  226  has a valved adapter and arterial lumen  228  does not have a valved adapter. 
   Referring to  FIGS. 12 and 13 , in use, a catheter apparatus  220 , similar to that described, is assembled, properly sterilized and otherwise prepared for storage, shipment and use in a hemodialysis procedure. A practitioner (not shown) manipulates distal end  224  of tubular body  222  for connection to a body cavity of a subject (not shown). Distal end  224  is inserted within a blood vessel of the subject. Catheter apparatus  220  is employed for administration of fluids that includes the simultaneous introduction of venous blood flow and withdrawal of arterial blood flow. Catheter apparatus  220  is inserted with the blood vessel of the subject such that blood is withdrawn, via arterial blood flow in a first direction, from the blood vessel for treatment by an artificial kidney device (not shown) and the treated blood is introduced back into the blood vessel, via venous blood flow in a second opposite direction. 
   Initially, the valve configuration that includes first port  254  and second port  280  is in the closed position. Surface  246  of first valve  238  engages surface  248  of proximal end  234  to create a fluid tight seal between first valve  238  and proximal end  234 , as discussed. First pusher  244  protrudes from proximal end  234 . Surface  272  of second valve  264  engages surface  274  of proximal end  260  to create a fluid tight seal between second valve  264  and proximal end  260 . Second pusher  270  protrudes from proximal end  260 . 
   Venous blood line  250  is attached to first luer fitting  242  such that pusher component  252  engages first pusher  244 , causing movement of first pusher  244  in a substantially distal direction, as shown by arrow DD, overcoming the bias of spring  250 . Surface  246  of first valve  238  disengages from surface  248  of proximal end  234  and the fluid tight seal is interrupted, thereby opening proximal end  234  to establish fluid communication between proximal end  234  and venous lumen  226  as facilitated by openings  289 . Venous blood flow is introduced to catheter apparatus  220  through proximal end  234  and into the blood vessel of the subject via venous lumen  226 . 
   Arterial blood line  276  is attached to second luer fitting  268  such that pusher component  278  engages second pusher  270 , causing movement of second pusher  270  in a substantially distal direction, as shown by arrow FF, overcoming the bias of spring  266 . Surface  272  of second valve  264  disengages from surface  274  of proximal end  260  and the fluid tight seal is interrupted, thereby opening proximal end  260  to establish fluid communication between proximal end  260  and arterial lumen  228 . Arterial blood flow may be received by arterial blood line  276 . 
   As first valve  238  is forced distally in the direction shown by arrow DD, discussed above, push rod portion  288  is similarly forced in the direction shown by arrow DD. First port  254  is movable corresponding to the movement of first valve  238 , as facilitated by push rod portion  288 . The valve configuration that includes first port  254  and second port  280  moves to the open position. First port  254  disengages from second port  280  to interrupt and open the fluid tight seal of second port  280 , thereby facilitating fluid communication between second port  280  and arterial lumen  228 . Thus, arterial blood flow is withdrawn from the blood vessel and received by arterial lumen  228  for receipt by arterial blood line  276 . 
   In the event that the practitioner desires to discontinue administration of fluids with the subject, the valve configuration that includes first port  254  and second port  280  may be returned to the closed position. Venous blood line  250  is removed from proximal end  234  to recreate the fluid tight seal between first valve  238  and proximal end  234 . Push rod portion  288  is caused to move back in the proximal direction, as shown by arrow CC, thereby sealing second port  280 . Arterial blood line  276  is removed from proximal end  260  to recreate the fluid tight seal between second valve  264  and proximal end  260 . 
   Referring to  FIGS. 14–18 , another alternate embodiment of the present disclosure is shown that includes a catheter apparatus  420 , similar to those described. Catheter apparatus  420  includes a tubular body  422  having a distal end  424 . Distal end  424  includes a cap  425  that is mounted with tubular body  422 . Cap  425  is separately formed and configured for assembly with tubular body  422  via threaded engagement. It is contemplated that cap  425  may be assembled by various attachment such as, for example, adhesive, interference or friction, snap engagement, etc. 
   Tubular body  422  defines a venous lumen  426  and an arterial lumen  428 . Venous lumen  426  and arterial lumen  428  are in a substantially side by side orientation along a distal portion  430  of tubular body  422 . The distal end of venous lumen  426  extends a greater length relative to the distal end of arterial lumen  428  for connection to the body cavity of a subject. As such, the distal end of arterial lumen  428  is recessed from the distal end of venous lumen  426 . Distal portion  430  may include a valve configuration, similar to those described herein with regard to  FIGS. 1–13 . 
   Venous lumen  426  includes a tubular venous adapter  432  that extends to a proximal end  434  thereof. Venous adapter  432  defines a valve housing  436 , including valve components, and a luer fitting  442 , similar to those described herein with regard to  FIGS. 1–13 . The valve components of valve housing  436  are biased to create a fluid tight seal with proximal end  434 . 
   First luer fitting  442  is configured for attachment to a venous blood line (not shown). The venous blood line is attached to first luer fitting  442  to overcome the bias of the valve components of valve housing  436 . The fluid tight seal is interrupted, thereby opening proximal end  434  to establish fluid communication between proximal end  434  and venous lumen  426 . Conversely, as the venous blood line is removed from proximal end  434 , the bias of the valve components of valve housing  436  recreates the fluid tight seal with proximal end  434 . Venous lumen  426  defines a first port  454  disposed adjacent distal end  424  that is configured for fluid flow. 
   Arterial lumen  428  includes a tubular arterial adapter  458  that extends to a proximal end  460  thereof. Arterial adapter  458  defines a valve housing  462 , including valve components, and a second luer fitting  468 , similar to those described herein with regard to  FIGS. 1–13 . The valve components of valve housing  462  are biased to create a fluid tight seal with proximal end  460 . 
   Second luer fitting  468  is configured for attachment to an arterial blood line (not shown). The arterial blood line is attached to second luer fitting  468  to overcome the bias of the valve components of valve housing  462 . The fluid tight seal is interrupted, thereby opening proximal end  460  to establish fluid communication between proximal end  460  and arterial lumen  428 . Conversely, as the arterial blood line is removed from proximal end  460 , the bias of the valve components of valve housing  462  recreates the fluid tight seal with proximal end  460 . Arterial lumen  428  defines a second port  480  disposed adjacent distal end  424  that is configured for fluid flow. 
   In use, catheter apparatus  420 , is inserted with the blood vessel of the subject. Tubular body  422  is then reverse tunneled under the skin of a subject (not shown) away from an insertion site to another exit site of the body of the subject. Tubular body  422  is sized as desired and cap  425  is threaded for assembly with tubular body  422 . Blood is withdrawn employing arterial lumen  428 , via arterial blood flow in a first direction, from the blood vessel for treatment by an artificial kidney device (not shown) and the treated blood is introduced back into the blood vessel employing venous lumen  426 , via venous blood flow in a second opposite direction. Catheter apparatus  420  is employed for administration of fluids that includes the simultaneous introduction of venous blood flow and withdrawal of arterial blood flow. 
   It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplification of the various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.