US20070078478A1 - Catheter and tunneling device therefor - Google Patents

Abstract

A catheter for introduction and removal of fluids from a body and tunneling device therefor, the catheter has a body having 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 lumens is integrally formed within a first end of the body and extends along side one another. The first conduit extends beyond the second conduit and forms a terminal point of the first end and defines a first opening thereat and the second conduit extends to a point short of the terminal point defining a second opening. A bumper portion is adjacent the second opening extending toward the terminal point. Another part of each the first and the second lumens are disjoined and form part of a second Y-shaped end. The tunneling device has a channel to removably receive the catheter.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation-in-part of copending application Ser. No. 11/161,212, filed Jul. 27, 2005, entitled CATHETER AND TUNNELING DEVICE THEREFOR, and Ser. No. 29/244,662, filed Dec. 13, 2005, entitled TUNNELING DEVICE FOR A CATHETER, both commonly assigned to the assignee of the present application, the disclosures of which are incorporated by reference in their entirety herein.
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 to 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 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'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'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.
SUMMARY OF THE INVENTION
• A feature of the present invention is to provide a catheter to ensure safe access to the blood circulatory system of humans and animals.
• Another feature 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 feature 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 feature 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 feature 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 feature of the invention is to improve long term health benefits for hemodialysis and plasmaphoresis patients with improved blood flow rates.
• Yet another feature 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. In one embodiment, the catheter includes a first lumen for removing fluid from the body and a second lumen for delivering fluid to the body wherein at least a part of each of the lumens is integrally connected within a first end of a catheter body and extends along side one another. The connected part of the first lumen, preferably the fluid delivering lumen, extends beyond the second lumen and forms a terminal point of the first end of the catheter and defines a first opening thereat. The connected part of the second lumen, preferably the fluid receiving lumen, 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 lumens each have another part which is disjoined at a joint to 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 Luer lock fitting.
• A first flexible obturator 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 Luer lock fitting of the first lumen. A second flexible obturator rod is provided and is of a size and length to extend through the second lumen in a slidably sealable manner and is equipped with an end cap which is configured to sealably connect to the Luer lock fitting of the second lumen. A clamp is operably disposed about each of the lumens.
• The first end can include one or more 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. In one embodiment, 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 joint of the catheter.
• A method of introducing the catheter into a body is also provided. Further features and advantages of the present invention will become apparent from the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• The invention is illustrated in the drawings in which like reference characters designate the same or similar parts throughout the figures of which:
• FIG. 1 shows one exemplary embodiment of a catheter of the present invention;
• FIG. 2 shows an end portion of the catheter ofFIG. 1;
• FIG. 3 shows a flexible rod for use in the catheter ofFIG. 1;
• FIG. 4 shows one exemplary embodiment of a tunneling device of the present invention;
• FIG. 5 shows the tunneling device inFIG. 4 with the catheter ofFIG. 1 disposed therein.
• FIG. 6 show cross-sections along line6-6 ofFIG. 5 and alternative cross-section shapes of the catheter;
• FIG. 7 shows the catheter ofFIG. 1 with flexible rods therein;
• FIG. 8 shows a schematic view of the catheter and tunneling device of the present invention as inserted through an entrance incision and extending through an exit incision;
• FIG. 9 shows a schematic view of the catheter as inFIG. 8, but with the tunneling device removed and the distal tip reinserted into the body through the exit incision; and
• FIG. 10 shows a first alternative exemplary design of the bumper and tip area.
• FIG. 11 shows second alternative exemplary design of the bumper and tip area.
• FIG. 12 shows a third alternative exemplary design of the bumper and tip area.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• Referring now to the drawings, the present invention in one exemplary embodiment is generally directed to acatheter10 for introduction and removal of fluids from a body B and atunneling device12 to more readily enable insertion of thecatheter10. Thecatheter10 includes afirst lumen14 for removing fluid from the body B and anotherlumen16 for delivering fluid to the body. Thelumens14 and16 includedistal lumen segments18,20, respectively, which are integrally connected as part of afirst end22 of thecatheter10 and extend along side one another. Preferably, thecatheter10 is made of a biologically inert, somewhat flexible, material, such as, but not limited to, a urethane or polyurethane-based material, such as CARBOTHANE® (available from Thermedics Corp.), polyether block amides, such as PEBAX® (available from Arkema Inc.) or other material known to those skilled in the art that possesses sufficient bioinertness, durability, flexibility and moldability or extrudability.
• Thefirst lumen14 can be the fluid delivering conduit (arterial flow) which extends beyond thesecond lumen16 as best seen inFIGS. 1 and 2 and forms aterminal point24 of the distalfirst end22 and defines afirst opening26 thereat. Thesecond lumen16 can preferably be the fluid receiving conduit (venous flow) which extends to a point short of theterminal point24 and defines asecond opening28. It is to be understood that thefirst lumen14 could be used for venous flow and thesecond lumen14 used for arterial flow. For illustrative purposes for the description below of the alternative lumen embodiments,lumen14 will be described as the arterial lumen andlumen16 described as the venous lumen. Also, abumper portion30, which can preferably be tapered, is integrally connected to thefirst end22 adjacent thesecond opening28 and extends toward the terminal point24 (other bumper and tip configurations are discussed hereinbelow). The external surface of the catheter10 (and/or the internal lumen walls) which is inserted into the body may have a bioactive material, such as a drug, protein or other material or materials, coated, impregnated or otherwise associated with the surface. In such a case the surface of the catheter may be treated to make association of the bioactive material with the wall more efficient. Such bioactive materials as well as surface materials and treatments are known to those skilled in the art and the present invention also contemplates adapting thecatheter10 to be able to use new bioactive materials and coating techniques developed hereafter.
• FIG. 6A shows a cross section of thecatheter10 showing a circular cross-section lumen configuration with each lumen being approximately the same size.
• FIG. 6B shows a first alternative embodiment cross-section lumen configuration in which thelumen14 is the arterial lumen and has athinner wall17. The thin lining of the arterial lumen provides sufficient rigidity to keep thecatheter10 open and also provides resistance to clotting. The venous lumen is relatively soft so that it may expand as the blood flow and venous pressure of the hemodialysis blood circuit is increased. The pliability of the venous lumen and the resulting expansion of the diameter of the venous lumen with increased blood flow aids in the reduction of the venous resistance within thecatheter10.
• FIG. 6C shows a second alternative embodiment cross-section lumen configuration in which thearterial lumen14 is larger than thevenous lumen16. Thearterial lumen14 contains a thin walled semi-rigid line19, which may be made of polytetrafluoroethylene (TEFLON®) or other flexible bioinert material. Upon forced flow by the blood pump of the dialysis machine (not shown), thevenous lumen16 increases in size in relation to the blood flow.
• FIG. 6D shows a third alternative embodiment cross-section lumen configuration in which a thin lining19 (made of material as described for liner19 above) of thearterial lumen14 provides sufficient rigidity to keep the catheter open as well as providing resistance to clotting. Thevenous lumen16 is relatively soft so that it may expand as the blood flow and venous pressure of the hemodialysis blood circuit is increased. In this alternative embodiment, twobumper portions30A and30B are employed.
• The first andsecond lumen segments18,20 are disjoined at a joint31 to define a proximal Y-shapedportion32 of thecatheter10. Eachlumen14 and16 includes a distal lumen segment33A and33B, respectively andterminal end34 and36, respectively, and defines arespective opening38 and40. Eachend34 and36 extends a sufficient length from the joint to permit easy and separate handling of each end during operative procedures by a surgeon. Eachend34 and36 can preferably be fitted with a Luer lock or other locking fitting42 and44, respectively, which fitting may have external thread or flange43.
• As shown in detail inFIG. 7, thefittings42,44 also include a flexible leaf valve or aseptum45, which can occlude fluid backflow and reduce the risk of air embolism. An obturator (also referred to as an occluding)rod46,50 (shown inFIGS. 3 and 7) extends from anend cap48,52. Eachend cap48,52 hasinternal thread53 which threadingly mates with the flange43. Therod46 is inserted through theopening40, through theleaf valve45 in the fitting44 and through the lumen segment33A and into thedistal lumen segment18. Theend cap48 is fitted onto the fitting42 and twisted to lock in position. Similarly, therod50 is inserted through theopening38, through theleaf valve45 in the fitting44 and through the lumen segment33B and into thedistal lumen segment20. Therods46,50 may be made of plastic, metal, or other material, or may be constructed of a metal wire core coated with plastic or other material or materials.
• As can be seen inFIG. 7, therods46 and50 can be a solid smooth surface, or, optionally include a bead-like outer surface which sealably abuts the inner wall of thelumens14 and16 to prevent air and fluid passage therethrough. Alternatively, the surface of the rod may have spaced protrusions or bumps of other regular or irregular geometric shapes. Theobturator rods46,50 not only occlude thelumens14,16, but, when drawn in and out, also clear the lumens of any fibrin which may have accumulated in the lumen.
• Disengageable clamps54 and56 are operably disposed about the proximal lumens segments33A,33B, respectively, as seen inFIG. 1.
• Thefirst end22 can include one or more (preferably two) spaced axial cuffs (shown in one exemplary embodiment inFIG. 1 as twocuffs58 and60) which provide for tissue ingrowth therein to enable thecatheter10 to be suitably anchored within the body B and also to reduce the possibility of infection at the incision site.
• Avisible indicia62 can preferably be formed or printed on thefirst end22 between thecuffs58 and60 and the joint31 (preferably about one centimeter from thecuff58 nearest the joint31) to serve as a position indicator of thecuffs58 and60 to the surgeon during the insertion procedure so as to provide an indication of thedistal tip26 of the catheter with respect to the cuff58.Preferably, a suture wing63 (known to those skilled in the art) is associated with thecatheter10, such as about the joint31 area to enable the surgeon to suture the catheter to the patient to maintain the position of thecatheter10 and prevent undesirable movement.
• In addition, the present invention provides for the tunneling device12 (also known as an introducer), shown inFIG. 4 (with thecatheter10 in position) andFIG. 5 (with thecatheter10 removed) for use in inserting thecatheter10. Thetunneling device12 can be a single piece construction. Thetunneling device12 can be of a relatively rigid bioinert material having at least some degree of flexibility, such as, but not limited to, medical grade stainless steel or synthetic plastic, e.g., polyurethane, or the like. Alternatively, the material can be a wire filament core inside of a plastic/silastic material. Thetunneling device12 includes ahandle64 and adistal portion66 which is of a length longer than thefirst end22 ofcatheter10 and is preferably configured with an exposedelongated channel68 to receive thefirst end22 of thecatheter10. Alternatively, thedistal portion66 may have a portion being achannel68 and a portion being closed to form a conduit. Thedistal portion66 is equipped with ahollow cap70 to receive theopenings26 and28 of thedistal end22 of thecatheter10 in a manner to maintain theopenings26 and28 substantially covered during insertion of thecatheter10 into the body B, thereby preventing potential clogging thereof by tissue and blood. Thecap70 can be a bullet-like or other shape tip which can be threadably connected to thedistal end69.
• Alternatively, at least a portion (preferably the distal end portion) of thecap70 can have a geometric cross-section shape (e.g., square, hexagonal or the like) or may have a surface texture adapted (e.g., knurls, ribs, ridges, cross-hatching, grooves, rings, bumps, or other raised or surface treatments or etching (e.g. acid), or other loss method of creating the grooves, lines, etc.) to increase the surgeon's ability to grasp thetip70 and unscrew it. Thehandle66 may also optionally have a cross-sectional shape or surface treatment or texture as described for thecap70 to similarly improve gripping by a (normally gloved) surgeon.
• Thechannel68 can be generally oval-shaped in cross-section as seen inFIG. 6 to accept theend22. Thetunneling device12 preferably includes a mid-section72 having a Y-shaped exposedchannel74 continuous with the exposedelongated channel68 to receive at least part of the joint31 and the lumen segments33A and33B. Thetunneling device12 of the present invention, and, particularly the roundedtip70, shields thecatheter tip26 and pulls thetip26 through the incision and opening more gently than currently available introducers.
• The present invention also provides a method of introducing the catheter into a body, as shown inFIGS. 8 and 9. Thecatheter10 andtunneling device12 can come pre-packaged for a surgeon with thecatheter10 already loaded into thetunneling device12. Once the surgeon has made the initial incision80, thetunneling device12 is inserted and advanced through the tissue of the body B to thesecond incision82 at the internal jugular, thecap70 is removed by unscrewing it from thetip69. The surgeon grasps thehandle64 with one hand and thedistal portion22 with the other hand at thesecond incision82, lifts the joint31 area of thecatheter10 from the Y-shaped exposedchannel74 and slowly removes thetunneling device12 back through the incision80. The exposedelongated channel68 of thetunneling device12 allows it to slide over thecatheter10 as it is removed, thereby minimizing movement of thecatheter10 while in the body. A second introducer (not shown, but known to those skilled in the art) may be placed over thecatheter tip26 area and thetip area26 is guided back into thesecond incision82 and to the jugular or other target site in situ (seeFIG. 9). The second introducer may be removed to leave the now indwellingcatheter10. Thecaps48,52 may be detached and therods46,50 withdrawn from thelumens14,16. Thesepta45 prevent backflow of blood or air. Thefittings42,44 may be connected to a dialysis system, as is known in the art. The invention usesflexible rods46 and50 to displace the blood in thecatheter lumens14 and16, when thecatheter10 is not being used. Thetunneling device12 is preferably intended for a single insertion. After it has withdrawn from the patient after use, it is disposed of. Alternatively, it may be possible to construct thedevice12 of a sterilizable material and, under certain application, may be reused.
• With the bumpers30 (and variations) of the present invention the need for anticoagulants is substantially reduced or eliminated, thereby substantially reducing or eliminating the risk of hemorrhaging acute and chronic gastrointestinal bleeding, retinopathy, and anemia due to the use of indwelling anticoagulants to maintain the blood vessel wall open and fibrin-free at the catheter tip area. Further, thedual cuffs58 and60 provide for improved anchoring into the patient's tissue as well as provide blockage to motile bacteria wherein theindicia62 indicates to the surgeon when thecuff58 and60 are close to exiting the incision site.
• An important feature of the present invention is the design of the distalfirst end22, as shown inFIG. 2. It is important to maintain flow of fluid at a high rate when desired. Thebumper30 maintains the blood vessel wall away from theopening28. Also, thedistal tip22 design stabilizes theend26 so that it maintains a relatively stable position generally near the axial center of the blood vessel and does not “whip” around within the blood vessel, which, among other detriments, can cause trauma or fatigue to the vessel wall. WhileFIG. 2 shows one preferred embodiment of thebumper30, other designs are possible. A first alternative exemplary embodiment is shown inFIG. 10, which shows adistal tip100 area with avenous lumen14 and anarterial lumen16, thearterial lumen16 having anopening102 which comprises a generally C-shaped opening having a first curved segment104 and a secondcurved segment106. Optionally, theinner wall16A of thelumen16 may have a thin lining or coating of a non-stick material, such as, but not limited to, polytetrafluoroethylene (TEFLON®).FIG. 11 shows a second alternative embodiment of adistal tip200area having lumens14,16 and anopening202. A bumper204 may have a hollow shape with openings206 and207 similar to thelumen16 opening and may have a curveddistal portion208 and a flattop area210 as shown in the drawing.FIG. 12 shows a third alternative exemplary embodiment of adistal tip300 having an opening302 comprised of a J-shaped curve. A bumper304 comprises one or more bumps orprotrusions306. As in the embodiment ofFIG. 10, the embodiments ofFIGS. 2, 11 and12 may be coated or lined as described.
• With all the above described alternative embodiments, the blood vessel wall is maintained open and away from occluding the arterial lumen opening by the different bumper configurations.
• The above described embodiments are set forth by way of example and are 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.

Claims (13)

1. A catheter for introduction and removal of fluids from a body, comprising:

a. a catheter body having

i. a first end,

ii. a first conduit for removing fluid from the body and

iii. a second conduit for delivering fluid to the body wherein a first part of each of the lumens is connected within a first end of said catheter body and extend along side one another, said connected first part of said first conduit extends beyond said connected first part of said second conduit and forms a terminal point of said first end and defines a first opening thereat and said second conduit extends to a point short of said terminal point defining a second opening,

iv. a bumper portion connected to said first end adjacent said second opening and extends toward said terminal point, and wherein a second part of each said first conduit and said second conduit are disjoined and form part of a second Y-shaped end of said catheter and said second part of each said conduit includes a terminal end defining an opening.

2. The catheter ofclaim 1, wherein said bumper is tapered.

3. The catheter ofclaim 1, wherein said bumper is integrally connected to said first end.

4. The catheter ofclaim 1, wherein each said disjoined conduit part extend a length to readily enable handling thereof during operation.

5. The catheter ofclaim 1, wherein each terminal end of said disjoined parts include a Luer lock fitting.

6. The catheter ofclaim 5, which includes a first flexible rod of a size and length to extend through said first conduit in a slidably sealable manner and is equipped with an end cap which is configured to sealably connect to said Luer lock fitting of said first conduit and a second flexible rod is of a size and length to extend through said second conduit in a slidably sealable manner and is equipped with an end cap which is configured to sealably connect to said Luer lock fitting of said second conduit.

7. The catheter ofclaim 1, which further includes a first and second clamp each operably disposed about one of said disjoined conduit parts.

8. The catheter ofclaim 1, which further includes at least one cuff disposed on said first end of said catheter which provide for tissue ingrowth therein to enable said catheter to be suitably anchored within the body.

9. The catheter ofclaim 1, which further includes a cuff disposed on said first end of said catheter which provides for tissue ingrowth therein to enable said catheter to be suitably anchored within the body and a visible indicia formed on said first end between said cuff and said second end of said catheter to serve as a position indicator of said cuff.

10. A tunneling device for use in inserting a catheter, comprising:

a. a relatively rigid member having a handle and an end configured with an exposed elongated channel to receive at least a portion of said catheter, wherein said end is equipped with a hollow cap to receive openings of a 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.

11. The tunneling device ofclaim 10, wherein said elongated channel is generally oval shaped in cross section.

12. The tunneling device ofclaim 10, which further includes a mid-section having a Y-shaped exposed channel continuous with said exposed elongated channel to receive at least part of a Y-shaped end of the catheter.

13. A method of introducing a catheter into a body, comprising the steps of:

a. providing a tunneling device comprising a relatively rigid member having a handle and an end configured with an exposed elongated channel to receive at least a portion of said catheter, wherein said end is equipped with a removable hollow cap to receive openings of a 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;

b. laying an end of the catheter through the exposed elongated channel in a manner such that end openings of the catheter are received in the cap of the tunneling device;

c. inserting the tunneling device having the catheter therein through a first incision of a body such that the cap extends out a second incision of the body;

d. removing the cap; and

e. lifting the first end of catheter from the tunneling device

f. removing said catheter from the tunneling device and

g. removing said tunneling device from the body.

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