U.S. patent application number 11/807105 was filed with the patent office on 2007-12-06 for multi-lumen catheter with protected tip.
This patent application is currently assigned to TwinCath, LLC. Invention is credited to Donald A. Schon.
Application Number | 20070282306 11/807105 |
Document ID | / |
Family ID | 38791245 |
Filed Date | 2007-12-06 |
United States Patent
Application |
20070282306 |
Kind Code |
A1 |
Schon; Donald A. |
December 6, 2007 |
Multi-lumen catheter with protected tip
Abstract
A multilumen catheter assembly (100) including a catheter (102)
having an elongated body (108) having a proximal end (104) and a
distal end (106) and a first lumen (122) with a first distal
opening (126) disposed at its distal end, and a second lumen (124)
connected to the first lumen but extending distally therebeyond to
a second distal opening (130). A protector (120) is adjoined to the
second lumen (124) distally of the first distal opening (126) and
extends radially and proximally to a free proximal edge (134) to
engage the vessel walls radially about the first distal opening to
center the catheter (102) within the vessel to prevent occlusion of
the first distal opening (126). A plurality of openings (136)
extend through the protector (120) to permit blood flow
therethrough.
Inventors: |
Schon; Donald A.; (Paradise
Valley, AZ) |
Correspondence
Address: |
ANTON P. NESS;FOX ROTHSCHILD LLP
1250 SOUTH BROAD STREET, SUITE 1000, P..O. BOX 431
LANSDALE
PA
19446-0431
US
|
Assignee: |
TwinCath, LLC
Paradise Valley
AZ
|
Family ID: |
38791245 |
Appl. No.: |
11/807105 |
Filed: |
May 25, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60810998 |
Jun 5, 2006 |
|
|
|
Current U.S.
Class: |
604/528 ;
604/96.01 |
Current CPC
Class: |
A61M 2025/1047 20130101;
A61M 2025/0037 20130101; A61M 2025/0031 20130101; A61M 25/0068
20130101; A61M 25/0082 20130101; A61M 25/0029 20130101 |
Class at
Publication: |
604/528 ;
604/96.01 |
International
Class: |
A61M 29/00 20060101
A61M029/00; A61M 25/00 20060101 A61M025/00 |
Claims
1. A multilumen catheter assembly comprising: an elongated body
having a proximal end and a distal end; a first lumen having a
sidewall extending between the proximal end and the distal end and
a first distal opening disposed at the distal end; and a second
lumen connected to the sidewall and extending between the proximal
end and a second distal end, distal of the first distal end,
wherein the second lumen includes a second distal opening disposed
distally of the first distal opening; and a protector adjoining the
second lumen distally of the first distal opening, the protector
adapted to extend from the distal end outwardly and proximally to a
free proximal edge that engages the vessel wall under spring bias
and radially about the catheter proximate the first distal opening,
thereby centering the catheter and facilitating prevention of
occlusion of the first distal opening by the vessel wall.
2. The assembly of claim 1, wherein the protector is pleated and is
adapted to be compressed radially toward the catheter during
catheter insertion and removal.
3. The assembly of claim 1, wherein the protector's free proximal
edge is rounded and continuous to facilitate being slid along the
vessel wall during insertion and removal of the catheter into and
from the vessel.
4. The assembly of claim 1, wherein the protector includes a
plurality of through openings that permit blood flow through the
protector.
5. The assembly of claim 4, wherein the through openings have
diameters of from about 0.01 in to about 0.10 in.
6. The assembly of claim 4, wherein the through openings have
diameters of from about 0.03 in to about 0.07 in.
7. The assembly of claim 4, wherein the through openings are at
least about 0.02 in from the proximal edge and the distal tip.
8. The assembly of claim 1, wherein the first distal opening opens
laterally of the catheter.
9. The assembly of claim 1, wherein the first lumen includes at
least one side port proximate the first distal opening.
10. The assembly of claim 1, wherein the second lumen, distally of
the first lumen distal tip section, includes a transition portion
that transitions the cross-section of the second lumen from a
generally noncircular cross section shape to a generally circular
cross section shape.
11. The assembly of claim 1, wherein the protector has a thickness
of from about 0.0010 in to about 0.0035 in.
12. The assembly of claim 1, wherein the protector has a thickness
of from about 0.0015 in to about 0.0025 in.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional
Application Ser. No. 60/810,998 filed Jun. 5, 2006.
FIELD OF THE INVENTION
[0002] The present invention relates to a multi-lumen catheter
assembly used to simultaneously withdraw and infuse a fluid to a
body, such as during hemodialysis.
BACKGROUND OF THE INVENTION
[0003] Catheters for the introduction or removal of fluids may be
placed in various venous locations and cavities throughout the body
for introduction or removal of these fluids. Such catheterization
may be performed by using a single catheter assembly having
multiple lumens. A typical example of a multiple lumen catheter
assembly is a dual lumen catheter in which one lumen introduces
fluid and the other lumen removes fluid. Such a multiple lumen
catheter assembly is known as the SPLIT STREAMS catheter,
manufactured and sold by Medical Components, Inc. of Harleysville,
Pa.
[0004] Generally, to insert any catheter into a blood vessel, the
vessel is identified by aspiration through a long hollow needle in
accordance with the well known Seldinger technique. When blood
enters a syringe attached to the needle, indicating that the vessel
has been found, a thin guide wire is then introduced, typically
through the puncturing needle or other introducer device into the
lumen of the vessel. The introducer device is then removed, leaving
the guide wire within the vessel. The guide wire projects beyond
the surface of the skin. At this point, several options are
available to a physician for catheter placement. The simplest is to
pass a catheter into the vessel directly over the guide wire. The
guide wire is then removed, leaving the catheter in position within
the vessel. However, this technique is only possible in cases where
the catheter is of a relatively small diameter, made of a stiff
material, and not significantly larger than the guide wire, for
example, for insertion of small diameter dual lumen catheters. If
the catheter to be inserted is significantly larger than the guide
wire, a dilator device is passed over the guide wire to enlarge the
opening into the vessel and then removed. The catheter is then
passed over the guide wire, and the guide wire is then removed,
leaving the catheter within the vessel for withdrawing blood into
the hemodialysis machine and returning dialysed blood to the
patient.
[0005] During hemodialysis, the two lumens, the arterial lumen and
the venous lumen, are connected to a hemodialysis machine and are
used to remove toxic blood from the patient for dialysis and to
return dialyzed blood to the patient, respectively. However,
suction of the toxic blood into the arterial lumen may draw the
distal opening of the arterial lumen against the wall of the blood
vessel into which the lumen is inserted, reducing or cutting off
blood flow through the arterial lumen, and significantly reducing
the amount of blood being dialyzed. This reduction in blood flow
can lead to longer dialysis period, or result in less dialysis of
the patient's blood. It would be beneficial to provide a catheter
that reduces the suction of the arterial lumen against the blood
vessel wall.
[0006] Twardowski et al., U.S. Pat. No. 5,405,320 and Davey et al.,
U.S. Pat. No. 6,280,423 B1 both disclose dual lumen catheters with
an arterial lumen that includes an overhanging lip or shield to
reduce the suction of the arterial lumen against the blood vessel
wall. Additionally, U.S. patent application Ser. No. 10/644,238
filed Aug. 20, 2003 discloses a dual lumen catheter with an
arterial lumen that includes a tip section that is undercut along
the venous lumen, thereby facilitating prevention of occlusion by
the vessel wall.
[0007] It is desired to provide a dual lumen catheter for
hemodialysis wherein the aspirating lumen is protected from
inadvertent occlusion by the vessel wall.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention is a dual lumen catheter having an
arterial lumen and a venous lumen with discrete, axially staggered
distal tip openings, wherein the venous lumen distal tip extends a
selected distance beyond the distal tip of the arterial lumen. The
arterial lumen is provided with an opening such as a side opening
as well as with several side port openings for withdrawing blood
from the body. The venous lumen provides return flow of the blood
into the vessel. In addition, the venous lumen distal tip portion
includes a protective structure proximal of the distal tip opening
that includes an enlarged proximal end that expands upon insertion
of the catheter into the vessel to engage the vessel wall, and
includes a plurality of openings therethrough to permit blood flow
therethrough. The protective structure centers the distal tip
portion of the venous lumen and also centers the distal tip portion
of the arterial lumen within the vessel wall whereby the arterial
distal tip opening is not sucked into occlusive engagement with the
vessel wall and diminish its efficiency in withdrawing blood from
the vessel.
[0009] Preferably the protective structure is thin and of soft
durometer and shaped like an umbrella, with a plurality of pleats
that extend proximally from the connection of the protective
structure with the venous lumen distal tip portion. Rounded
proximal edge portions of the protective structure facilitate later
removal of the catheter from the vessel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying drawings, which are incorporated herein and
constitute part of this specification, illustrate the presently
preferred embodiments of the invention, and, together with the
general description given above and the detailed description given
below, serve to explain the features of the invention. In the
drawings:
[0011] FIG. 1 is a side view of a dual lumen catheter containing
the present invention;
[0012] FIG. 2 is an enlarged side view of the distal portion of the
catheter of FIG. 1 after insertion of the catheter into a vessel,
with the protective structure expanded to engage the vessel walls,
and the flow of the blood in the vessel and into and from the
arterial and venous distal tip openings, respectively; and
[0013] FIG. 3 is a cross-sectional view of the distal portion of
the catheter of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
[0014] In the drawings, like numerals indicate like elements
throughout. Certain terminology is used herein for convenience only
and is not to be taken as a limitation on the present invention.
The terms "distal" and "proximal" refer to directions away from and
closer to, respectively, the insertion tip of the catheter
according to the present invention. The terminology includes the
words specifically mentioned, derivatives thereof and words of
similar import. The embodiments illustrated below are not intended
to be exhaustive or to limit the invention to the precise form
disclosed. These embodiments are chosen and described to best
explain the principle of the invention and its application and
practical use and to enable others skilled in the art to best
utilize the invention.
[0015] In the FIG. 1, a dual lumen catheter assembly 100 is
illustrated that includes a catheter 102 having a proximal end 104,
a distal end 106, and an elongated body 108 extending therebetween.
Catheter 102 comprises first and second catheter lumens, one being
known as a venous lumen for returning blood to the patient, and the
other being known as an arterial lumen for withdrawing blood from
the patient. While the catheter body 108 preferably has a generally
circular cross section, the first and second lumens each may have a
generally "D-shaped" cross section, juxtaposed from each other
across a common sidewall. Alternatively, the lumens of the catheter
could have a round or oval cross-sectional shape, and the two
lumens could be attached side-by-side or be split apart at the
distal end. It is preferred that the cross section of the body 108
be a generally smooth curve to facilitate sealing of the patient's
skin around the body 108 at the incision site, as well as at the
entrance to the vessel, to minimize bleeding.
[0016] A hub 110 is affixed onto the proximal end 104 of catheter
102, and preferably includes a suture wing that extends generally
transverse of the body 108 and is shown to have two suture openings
that allow an inserting physician to suture the hub 110 to the
external skin of the patient into whom the physician has inserted
the catheter assembly 100 to prevent the catheter assembly 100 from
being dislodged from its inserted position within the patient.
[0017] Joined to the proximal ends of the first and second lumens
of the catheter 102 are first and second extension tubes 112 that
fluidly communicate respectively with the first and second lumens
within conduits of hub 110. Proximal ends of the first and second
extension tubes 112 preferably terminate at a first and second
connectors 114, such as standard luer locks, as is well known in
the art. First and second clamps 116, such as a Roberts clamps, are
preferably disposed over the first and second extension tubes 112
and serve to releasably close off each of the first and second
extension tubes respectively, preventing fluid flow through each of
the first and second extension tubes 112 when the respective clamps
are in the closed position.
[0018] Preferably, a catheter tissue ingrowth cuff 118 is disposed
along an exterior of the body 108 between the distal tip 106 and
the hub 110. The catheter tissue ingrowth cuff 118 is used for
chronic catheter insertions, wherein the catheter assembly 100 is
intended to be inserted into the patient for extended periods of
time, such as for several months. The catheter tissue ingrowth cuff
118 is disposed within a subcutaneous tunnel according to methods
known by those skilled in the art.
[0019] With respect to FIGS. 2 and 3, the present invention
includes a distal tip protector 120 integrally defined on the
distal tip 106 of catheter 102. In these figures, the distal
portion of the catheter is shown in position inserted within a
venous vessel V. Catheter 102 is shown to include first lumen 122
for withdrawal of fluids from venous vessel V, and second lumen 124
for returning blood that was withdrawn from the vessel to be
returned to the vessel. The distal tip of second lumen 124 is
located a distance distally of the distal tip of the first lumen,
which minimizes any tendency of returned blood to be aspirated by
the first lumen and which thus enhances the efficiency of the
hemodialysis. Flow of blood generally within the vessel V is shown
by directional arrow A. Flow of blood within first or arterial
lumen 122 is shown by directional arrow B, with its intake
occurring at first distal lumen opening 126 and preferably through
one or more side ports 128; also, the distal tip of lumen 122 may
be open. Flow of blood within second or venous lumen 124 is shown
by directional arrow C, with flow exiting from the lumen into the
vessel from second distal lumen opening 130 and being parallel to
vessel blood flow A.
[0020] Distal tip protector 120 is generally shaped like an
umbrella or mushroom, and has numerous pleats 132 that allow the
protector 120 to be compressed for insertion into the vessel.
Protector 120 also includes a generally rounded bottom edge 134
that allows the catheter to be eventually slid out of the vessel
for removal. A plurality of through-openings 136 are defined on the
protector to allow blood flowing through the vessel past first
distal opening 126, to continue flowing through and past the
protector.
[0021] First distal lumen opening 126 is shown to be directed
laterally, not axially, to further lessen the tendency of
aspiration of returned blood exiting from second distal lumen
opening 130. However, such lateral orientation, without the
protector 120 of the present invention, would make the opening
susceptible to occlusion by the vessel wall. Protector 120,
however, while being quite flexible to facilitate insertion and
removal of the catheter into and from the patient, is sufficiently
rigid for rounded bottom edge 134 to press against the vessel wall
and to center the distal catheter portion within the vessel V thus
preventing occlusion of first distal lumen opening 126.
[0022] Preferably, the body 108 is constructed from a polymer or
elastomer, such as polyurethane or silicone, with a radiopaque
filler material therein to aid in locating the body 108 within the
patient's vessel after insertion, such as by ultrasound and
fluoroscopy. However, those skilled in the art will recognize that
other biocompatible materials may be used for the body 108.
Preferably, the body 108 has a hardness of approximately 70-A to
80-A on the Shore durometer scale, although those skilled in the
art will recognize that the body 108 may be harder or softer. The
thickness of tip protector 120 could be in the range of from about
0.0010 in (0.254 mm) to about 0.0035 in (0.889 mm), and more
preferably, from about 0.0015 in (0.381 mm) to about 0.0025 in
(0.635 mm). If the material used is silicone elastomer, the
thickness may be slightly thicker. Protector 120 could be molded
integrally with catheter body 108, but it could be solvent bonded
or fused thereto. Regarding holes 136, they may each have a size of
about 0.01 in (2.54 mm) to about 0.10 in (25.4 mm), and more
preferably from about 0.03 in (7.62 mm) to about 0.07 in (17.8 mm).
All holes 136 should be relatively spaced away a slight distance
from distal tip 130 and bottom edge 134 to preserve structural
integrity, and be spaced apart from each other about 0.02 in (5.08
mm), for example. Openings 136 could have different diameters from
each other, if desired; for example, the openings near to distal
tip 130 could be smaller than those near rounded proximal or bottom
edge 134. The openings could have rounded, oblong or oval or other
shapes, as desired. The holes could also be aligned in four or five
columns extending longitudinally along the axis of the lumen.
[0023] To insert the catheter assembly 100 into the patient, an
incision is initially made near an insertion site on the patient's
skin, which is to be aspirated with a syringe or other introducer
apparatus near or proximate the area to be catheterized. If the
catheter assembly 100 is used for hemodialysis and the area to be
catheterized is the internal jugular vein, the incision is made in
the supra-clavicular triangle region. The exact location of the
incision can be varied by the physician. Initially, the proximal
portion of the catheter would have been located within a
subcutaneous tunnel in the subcutaneous area of the patient's
torso, using one of various tunneling techniques. In one preferred
technique, the distal end region of the catheter would have been
pulled through the tunnel from a remote end of the tunnel, with the
tunnel formed using a trocar or other tunneling tool, leaving the
proximal end region at least partially within the tunnel, with the
proximal end extending beyond the tunnel and exterior of the
patient. In accordance with the Seldinger technique, a hollow
needle is inserted through the incision and into the vein, and the
vein is then aspirated. A guide wire is then passed through the
needle and the needle is removed. Next, after dilating the soft
tissue track and venatory site, the catheter assembly 100 is
inserted over the guide wire. This insertion technique eliminates
the need for a sheath to be inserted over the guide wire, greatly
reducing the risk of air embolism.
[0024] In use, after the dialysis machine is connected to the
catheter assembly 100 and turned on, the dialysis machine draws
blood from the vessel through the first lumen 122. In the event
that the pressure drop in the vessel caused by the blood being
drawn into the first lumen 122 forces the wall of the vessel toward
the first distal opening 126, the protector 120 prevents the vessel
wall from totally occluding the first distal opening 126 and
shutting off blood flow through the first lumen 122.
[0025] The blood drawn into the first lumen 122 flows to the
hemodialysis machine where the blood is cleaned and processed. The
blood is then pumped through the second lumen 124 for discharge
back into the vessel through second distal opening 130 and side
holes 136.
[0026] It will be appreciated by those skilled in the art that
changes could be made to the embodiments described above without
departing from the broad inventive concept thereof. It is
understood, therefore, that this invention is not limited to the
particular embodiments disclosed, but it is intended to cover
modifications within the spirit and scope of the present invention
as defined by the appended claims.
* * * * *