Patent Publication Number: US-2009221950-A1

Title: Catheter and tunneling device therefor

Description:
FIELD OF INVENTION 
     The present invention relates to catheters and more particularly to an improved catheter for introduction and removal of fluids from a body and a tunneling device to more readily enable insertion of the catheter. 
     BACKGROUND OF THE INVENTION 
     Medical catheters have been used successfully for many years to access the blood stream of human and animal patients. Multi-lumen catheters are used for a variety of applications where it is necessary to have two or more separate fluid pathways. The purposes of accessing the blood circulatory system include introduction of medication, hemodialysis therapy, plasmaphoresis therapy, and other therapies which may require access to the blood circulatory system. 
     In the case of hemodialysis, a dual-lumen catheter can be employed to simultaneously accommodate opposing blood flow. One lumen aspirates blood from a blood vessel of a patient to a dialysis machine where it is processed for the removal of toxins, while the other lumen infuses the purified blood to the patient. 
     A problem in many dialysis catheters is that related to clotting and fibrin sheath formation around the “arterial” inlet used for aspiration of blood from a patient. Thrombus and fibrin can occlude distal tips or other places throughout the length of the catheter lumens, resulting in loss of catheter function when such an occlusion prevents blood flow. Usually, catheters have one large exposed hole or one large hole with many little side holes. The thought process is that the extra holes will prevent the inlet from sucking up against the blood vessel wall. Unfortunately, the small holes become filled with fibrin and the large inlet hole develops a trap door clot, which makes the catheter useless. A secondary problem is that related to the arterial lumen “sucking” against the vessel wall in which it resides. This problem can occur if the arterial lumen ports become fully occluded by the patient&#39;s vasculature. A technique to resolve such problem is to reverse the bloodlines (i.e., to aspirate through the longer lumen, and to infuse through the shorter lumen, contrary to normal therapeutic pump blood flow). This causes cleaned blood to flow directly toward the lumen that is under vacuum, line reversal in certain catheters can result in inefficient flow and (high re-circulation). 
     Additionally, there are major side effects which carry patient safety issues, such as hemorrhaging due to the use of indwelling anticoagulants. These anticoagulants are used when the catheter is not being utilized. Side effects of these anticoagulants, primarily heparin, cause acute and chronic gastrointestinal bleeding, retinopathy, and anemia. 
     Another major issue is that of infection. Currently, catheters on the market use only one single cuff immediately beneath the skin, which is expected to anchor the catheter into the patient&#39;s tissue, as well as provide blockage to motile bacteria. This cuff design is often inadequate to perform these functions. 
     The present invention solves many of the above problems associated with catheters as will become apparent in reading the following hereinafter. 
     BRIEF SUMMARY OF THE INVENTION 
     An object of the invention is to ensure safe access to the blood circulatory system of humans and animals. 
     Another object of the invention is to enable catheter access to the blood circulatory system of humans and animals without the need for an indwelling anticoagulant. 
     Yet another object of the invention is to provide a catheter inlet which is substantially less prone to be blocked off as a result of sucking up against the blood vessel wall. 
     A further object of the invention is to provide a catheter that has the ability to substantially prevent clotting of the lumens of the catheter without the need of clot busting agents. 
     Another object of the invention is to provide a catheter with the ability to reduce long term infections that accompany long term placement of central venous lines. 
     A further object of the invention is to improve long term health benefits for hemodialysis and plasmaphoresus patients with improved blood flow rates. 
     Yet another object of the invention is to provide a catheter that can safely access the blood circulatory system of humans and animals with minimal risk of air embolism. 
     Accordingly, the present invention is directed to a catheter for introduction and removal of fluids from a body and a tunneling device to more readily enable insertion thereof. The catheter includes a first conduit for removing fluid from the body and a second conduit for delivering fluid to the body wherein at least a part of each of the conduits is integrally connected within a first end of a catheter body and extends along side one another. The connected part of the first conduit, preferably the fluid delivering conduit, extends beyond the second conduit and forms a terminal point of the first end of the catheter and defines a first opening thereat. The connected part of the second conduit, preferably the fluid receiving conduit, extends to a point short of the terminal point and defines a second opening. Also, a bumper portion, which can preferably be tapered, is integrally formed onto the first end adjacent the second opening and extends toward the terminal point. 
     The first and second conduits each have another part which is disjoined at a second Y-shaped end of the catheter. Each disjoined part of each includes a terminal end defining and opening. Each end can preferably be fitted with a lure lock fitting. 
     A first flexible rod is provided and is of a size and length to extend through the first conduit in a slidably sealable manner and is equipped with an end cap which is configured to sealably connect to the lure lock fitting of the first conduit. A second flexible rod is provided and is of a size and length to extend through the second conduit in a slidably sealable manner and is equipped with an end cap which is configured to sealably connect to the lure lock fitting of the second conduit. A clamp is operably disposed about each of the conduits. 
     The first end can include a plurality of longitudinally spaced cuffs which provide for tissue ingrowth therein to enable the catheter to be suitably anchored within the body. A visible indicia can preferably be formed on the first end between the cuffs and the second end to serve as a position indicator of the cuffs. 
     In addition, the present invention provides for a tunneling device for use in inserting the catheter. The tunneling device includes a relatively rigid member having a handle and an end which is of a length longer than the first end of catheter and is configured with an exposed elongated channel to receive the first end of the catheter. The tunneling device end is equipped with a hollow cap to receive the openings of the first end of the catheter in a manner to maintain the openings substantially covered during insertion of the catheter into the body thereby preventing potential clogging thereof by tissue and blood. The channel can be generally oval shaped to contain the connected conduit parts of the catheter. Further, the tunneling device can include a mid section having a Y-shaped exposed channel continuous with the exposed elongated channel to receive at least part of the Y-shaped end of the catheter. 
     A method of introducing the catheter into a body is also provided. Further objects and advantages of the present invention will become apparent from the ensuing description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         FIG. 1  shows a catheter of the present invention; 
         FIG. 2  shows an end portion of the catheter of  FIG. 1 ; 
         FIG. 3  shows a flexible rod for use in the catheter of  FIG. 1 ; 
         FIG. 4  shows a tunneling device of the invention; 
         FIG. 5  shows the tunneling device in  FIG. 4  with the catheter of  FIG. 1  disposed therein; 
         FIG. 6  shows a cross-section along line  6 - 6  of  FIG. 5 ; 
         FIG. 7  shows the catheter of  FIG. 1  with flexible rods therein; 
         FIG. 8  depicts one step of use of the invention; and 
         FIG. 9  depicts another step of use on the invention. 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring now to the drawings, the present invention is generally directed to a catheter  10  for introduction and removal of fluids from a body B and a tunneling device  12  to more readily enable insertion of the catheter  10 . The catheter  10  includes a first conduit  14  for removing fluid from the body B and another conduit  16  for delivering fluid to the body. Parts  18  and  20  of each of the conduits  14  and  16 , respectively, are integrally connected as part a first end  22  of the catheter  10  and. extend along side one another. 
     The first conduit  14  can preferably be the fluid delivering conduit (venous flow) which extends beyond the second conduit  16  as best seen in  FIGS. 1 and 2  and forms a terminal point  24  of the first end  22  and defines a first opening  26  thereat. The second conduit  16  can preferably be the fluid receiving conduit (arterial flow) which extends to a point short of the terminal point  24  and defines a second opening  28 . Also, a bumper portion  30 , which can preferably be tapered, is integrally connected to the first end  22  adjacent the second opening  28  and extends toward the terminal point  24 . 
     The first and second conduits  14  and  16  are disjoined at a second Y-shaped end  32  of the catheter  10 . Each conduit  14  and  16  includes a terminal end  34  and  36 , respectively, defines a respective opening  38  and  40 . Each end  34  and  36  extend a sufficient length from the point of connection of parts  18  and  20  to permit easy handling of each during operative procedures by a surgeon. Each end  34  and  36  can preferably be fitted with a lure lock fitting  42  and  44 , respectively, which can be separate or part of a flexible rod  46  or  50 , and include a respective flexible leaf valve  45  and  51  (not shown) through which the rods  46  or  50  pass through upon insertion/removal of the catheter  10 . 
     As seen in  FIG. 7 , the first flexible rod  46  is of a size and length to extend through the first conduit  14  in a slidably sealable manner and is equipped with an end cap  48  which is configured to sealably connect to the lure lock fitting  42  of the first conduit  14 . The second flexible rod  50  is of a size and length to extend through the second conduit  16  in a slidably sealable manner and is equipped with an end cap  52  which is configured to sealably connect to the lure lock fitting  44  of the second conduit  16 . As can bee seen in  FIG. 7 , the rods  46  and  50  can include a bead like outer surface which sealably connects to the inner wall of the conduits  14  and  16  to prevent air passage thereby. Clamps  54  and  56  are operably disposed about the conduits  14  and  16 , respectively, as seen in  FIG. 1 . 
     The first end  22  can include a plurality of longitudinally spaced cuffs  58  and  60  which provide for tissue ingrowth therein to enable the catheter  10  to be suitably anchored within the body B. A visible indicia  62  can preferably be formed on the first end  22  between the cuffs  58  and  60  and the second end  32  to serve as a position indicator of the cuffs  58  and  60  to the surgeon during the insertion procedure. 
     In addition, the present invention provides for the tunneling device  12  for use in inserting the catheter  10 . The tunneling device  12  can be a single piece construction. The tunneling device  12  can be of a relatively rigid material, such as medical grade stainless steel or synthetic plastic, e.g., polyurethane. The tunneling device  12  includes a handle  64  and an end  66  which is of a length longer than the first end  22  of catheter  10  and is configured with an exposed elongated channel  68  to receive the first end  22  of the catheter  10 . The tunneling device end  66  is equipped with a hollow cap  70  to the to receive the openings  26  and  28  of the first end  22  of the catheter  10  in a manner to maintain the openings  26  and  28  substantially covered during insertion of the catheter  10  into the body B thereby preventing potential clogging thereof by tissue and blood. The cap  70  can be a bullet like tip which can be threadably connected to the end  66 . The channel  68  can be generally oval shaped in cross section as seen in  FIG. 6  to accept the end  22 . Further, the tunneling device  12  can include a mid section  72  having a Y-shaped exposed channel  74  continuous with the exposed elongated channel  68  to receive at least part of the Y-shaped end  32  of the catheter  10 . 
     A method of introducing the catheter into a body is also provided. The catheter  10  and tunneling device  12  can come pre-packaged for a surgeon with the catheter  10  already loaded into the tunneling device  12 . Once the surgeon has pushed the tunneling device  12  through the tissue of the body B to the incision at the internal jugular, the cap  70  is removed. The surgeon grasps the end  22  of the catheter  10  at the incision, lifts the Y-shaped end  32  of the catheter  10  from the Y-shaped exposed channel  74  and slowly removes the tunneling device  12 . The exposed elongated channel  68  of the tunneling device  12  allows it to slip around the catheter  10  it is removed. The tunneling device  12  is only intended for a single insertion. After it has accomplished its task, it is dispensed. The invention uses flexible rods  46  and  50  to displace the blood in the catheter conduits  14  and  16 , when the catheter  10  is not being used. 
     With the present invention, there is a substantially reduced or elimination of risk of hemorrhaging due to the use of indwelling anticoagulants, acute and chronic gastrointestinal bleeding, retinopathy, and anemia. Further, the dual cuffs  58  and  60  provide for improved anchoring into the patient&#39;s tissue as well as provide blockage to motile bacteria wherein the indicia  62  indicates to the surgeon when the cuffs  58  and  60  are close to exiting the incision site. 
     The above described embodiment is set forth by way of example and is not for the purpose of limiting the present invention. It will be readily apparent to those skilled in the art that obvious modifications, derivations and variations can be made to the embodiment without departing from the scope of the invention. Accordingly, the claims appended hereto should be read in their full scope including any such modifications, derivations and variations.