U.S. patent application number 11/091167 was filed with the patent office on 2005-08-04 for catheter assembly with joinable catheters.
Invention is credited to Cunningham, Jon.
Application Number | 20050171469 11/091167 |
Document ID | / |
Family ID | 32175721 |
Filed Date | 2005-08-04 |
United States Patent
Application |
20050171469 |
Kind Code |
A1 |
Cunningham, Jon |
August 4, 2005 |
Catheter assembly with joinable catheters
Abstract
A multiple lumen catheter assembly comprising a first catheter
having a proximal end and a distal end, a second catheter having a
proximal end and a distal end; and a connecting means for
selectively joining at least a portion of the distal ends of the
first and second catheters.
Inventors: |
Cunningham, Jon; (Cumming,
GA) |
Correspondence
Address: |
TECHNOPROP COLTON, L.L.C.
P O BOX 567685
ATLANTA
GA
311567685
|
Family ID: |
32175721 |
Appl. No.: |
11/091167 |
Filed: |
March 28, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11091167 |
Mar 28, 2005 |
|
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10287566 |
Nov 4, 2002 |
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Current U.S.
Class: |
604/43 |
Current CPC
Class: |
A61M 2025/0037 20130101;
A61M 2025/0031 20130101; A61M 25/0029 20130101; A61M 25/0043
20130101 |
Class at
Publication: |
604/043 |
International
Class: |
A61M 003/00 |
Claims
What is claimed is:
1. A multiple lumen catheter assembly comprising: a) a first
catheter having a proximal end and a distal end; b) a second
catheter having a proximal end and a distal end; and c) a
connecting means for selectively joining at least a portion of the
distal ends of the first and second catheters, wherein a first
fluid flow in the first catheter is in a direction different from a
second fluid flow in the second catheter.
2. The catheter assembly as claimed in claim 1, wherein the first
catheter and the second catheter are selectively joinable at at
least one position along generally flat side surfaces.
3. The catheter assembly claimed in claim 1, whereby the joining of
the first catheter and second lumens catheter decreases the
distance between the first catheter and the second catheter
proximal to the distal ends of the first catheter and the second
catheter.
4. The catheter assembly claimed in claim 1, wherein the first
catheter and the second catheter each have a generally
semi-circular cross section and each comprise at least one of the
generally flat side surfaces.
5. The catheter assembly claimed in claim 1, wherein the connecting
means includes at least one lockable junction comprising a male end
and female end, whereby the first catheter and the second catheter
are joined selectively along a portion of the distal ends of the
first catheter and the second catheter through the joining of the
male end with female end.
6. The catheter assembly claimed in claim 1, wherein the connecting
means is an adhesive.
7. The catheter assembly claimed in claim 4 further comprising a
third catheter.
8. A multiple lumen catheter assembly comprising: a) a first
catheter having a proximal end and a distal end; b) a second
catheter having a proximal end and a distal end; c) a connecting
means for selectively joining together at least a portion of the
distal ends of the first catheter and second catheter, wherein the
connecting means allows the first lumen catheter and the second
catheter to be selectively joined together at the discretion of a
practitioner at a position proximal to the distal ends of the first
catheter and second catheter, wherein a first fluid flow in the
first catheter is in a direction different from a second fluid flow
of the second catheter, and whereby the selective joining of the
first catheter and second catheter decreases the distance between
the first catheter and second catheter proximal to the distal ends
of the first catheter and second catheter.
9. The catheter assembly as claimed in claim 8, wherein the distal
end of the first catheter extends beyond the distal end of the
second catheter.
10. The catheter assembly as claimed in claim 8, wherein the distal
end of the first catheter extends beyond the distal end of the
second catheter within a patient and the first catheter is for
introducing a fluid into a blood vessel in the patient and the
second catheter is for removing a fluid from another blood
vessel.
11. The catheter assembly as claimed in claim 8, wherein the first
catheter and the second catheters cannot be joined beyond a
preselected point between the proximal end and the distal end of
each of the first catheter and the second catheter.
12. The catheter assembly as claimed in claim 8, wherein the
connecting means includes at least one lockable junction comprising
a male end and female end, whereby the first catheter and the
second catheter are joined selectively along a portion of the
distal ends of the first catheter and the second catheter through
the joining of the male end with female end.
13. A multiple lumen catheter assembly, comprising: a) a first
lumen catheter defined by a first outer wall and having a proximal
end and a distal end; b) a second catheter defined by a second
outer wall and having a proximal end and a distal end, wherein a
first fluid flow in the first catheter is in a direction different
from a second fluid flow in the second catheter, the first catheter
and the second catheter are joinable at at least one point along
the first outer wall and the second outer wall by a connecting
means, and the connecting means allows the first lumen catheter and
the second catheter to be selectively joined at the discretion of a
practitioner, whereby the selectively joining of the first catheter
and the second catheter decreases the separation distance between
the first catheter and the second catheter proximal to the distal
ends of the first lumen catheter and the second catheter.
14. The catheter assembly as claimed in claim 13, wherein the
connecting means is at least one lockable junction comprising a
male end and female end, whereby the first catheter and the second
catheter are joined selectively along a portion of the distal ends
of the first n catheter and the second catheter through the joining
of the male end with female end.
15. The catheter assembly as claimed in claim 14, wherein the
connecting means is an adhesive on the outer wall of at least one
of the catheters.
16. The catheter assembly as claimed in claim 15, wherein the first
catheter and the second catheter cannot be joined beyond a
preselected point set between the proximal end and the distal end
of each of the first catheter and the second catheter.
17. The catheter assembly as claimed in claim 16, wherein catheter
assembly is a hemodialysis catheter assembly.
18. The catheter assembly as claimed in claim 17, wherein the first
catheter is introduced into a blood vessel and the second catheter
is introduced into a blood vessel.
19. A multiple lumen hemodialysis catheter assembly, comprising: a)
a first lumen catheter defined by a first outer wall and having a
proximal end and a distal end; b) a second catheter defined by a
second outer wall and having a proximal end and a distal end,
wherein a first fluid flow in the first catheter is in a direction
different from a second fluid flow in the second catheter, the
first catheter and the second catheter are joinable at at least one
point along the first outer wall and the second outer wall by a
connecting means, the connecting means allows the first lumen
catheter and the second catheter to be selectively joined at the
discretion of a practitioner, and the first catheter and the second
catheter cannot be joined beyond a preselected point set between
the proximal end and the distal end of each of the first catheter
and the second catheter, whereby the selectively joining of the
first catheter and the second catheter decreases the separation
distance between the first catheter and the second catheter
proximal to the distal ends of the first lumen catheter and the
second catheter.
20. The catheter assembly as claimed in claim 19, wherein the
connecting means is selected from the group consisting of lockable
junctions and adhesives.
Description
STATEMENT OF RELATED APPLICATIONS
[0001] This patent application is a continuation application of and
claims priority on U.S. patent application Ser. No. 10287566
entitled "Catheter Assembly With Joinable Catheters" having a
filing date of 4 Nov. 2002, currently pending.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates generally to the field of
catheters for use in applications that require blood, fluids,
medicated solutions, and other solutions to be removed from and
introduced into a person. More particularly, the present invention
relates to catheters having dual or multiple independent catheters
in which a practitioner can control the distance of separation
between the lumens at the distal end of the catheters.
[0004] 2. Prior Art
[0005] Hemodialysis, one procedure that requires the introduction
and removal of blood from a patient, is a routine treatment for
patients with renal failure. When patients are placed on
hemodialysis, such patients require the placement of a catheter
into a large blood vessel through a subcutaneous tunnel. In
conventional procedures including the Seldinger technique, the
catheter is inserted into the patient's blood vessel. This
catheter, termed a hemodialysis catheter, is connected to a
hemodialysis machine and is the vital connection between the
patient and the hemodialysis unit. Once the practitioner has
properly inserted the hemodialysis catheter into the patient,
reliable hemodialysis can be performed for weeks to months using
the placed catheter.
[0006] U.S. Pat. Nos. 6,190,349 and 5,947,953 to Ash et al.
disclose a multiple catheter assembly and methods for inserting the
same, in which first and second catheters are connected by a
splittable membrane. The catheter assemblies in Ash '349 and Ash
'953 comprise at least two independent catheters that are
splittable to a length not predetermined by the catheter assembly.
As the catheter assemblies in Ash '349 and Ash '953 are splittable
as such, it may be possible to split or separate the catheters from
each other within the assembly substantially beyond a desired or
desirable length, which in some cases can impair the function of
the catheter assembly. The thinness of the membrane initially
holding the two lumens to each other makes this a likely
possibility. Similarly, once the Ash '349 and Ash '953 lumens are
split from each other, they cannot be reattached to each other.
[0007] U.S. Pat. No. 6,001,079 to Pourchez discloses a multilumen
catheter comprising two lumens defined by a single wall for guiding
a fluid. The Pourchez '079 catheter is for the circulation of at
least one fluid between a patient's body cavity or vessel and a
fluid circulating means. Although the Pourchez '079 catheter has
separated catheter lumen tips, the distance between the lumen tips
is predetermined and is not adjustable. Further, the unseparated
portion of the lumens of the Pourchez '079 catheter are joined
together and are not independent as they share a common wall. As
the Pourchez '079 catheter has a set separation distance between
the two lumens, which cannot be changed, the Pourchez '079 catheter
may not be useful for a wide variety of sizes of patients.
[0008] Accordingly, there is a need for an improved catheter, more
particularly a hemodialysis catheter with improved stability and
performance. Further, there is a need for a catheter that can
remain within a patient with less chest discomfort. It is to this
and other needs that the present invention is directed.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention includes a catheter assembly with
multiple joinable catheters such that the distance between the two
catheters at distal ends of the catheters can be varied. While the
invention is described herein in conjunction with the preferred and
illustrative embodiments, it will be understood that the invention
is not limited to these embodiments.
[0010] The catheter assembly of the present invention is intended
for use in applications in which bodily fluids, medicated
solutions, and other solutions are introduced into and/or removed
from the body. For example, in the case of hemodialysis treatment,
one embodiment of the invention is useful for the removal of blood
from a patient for purification and for reintroducing the blood
into the patient after purification through the same blood vessel.
In such applications, the catheter assembly can be used in many
blood vessels including the femoral blood vessels, subclavian blood
vessels or other blood vessels.
[0011] The catheters of the present invention have two ends that
have distinctive functions. More particularly, a distal end of each
catheter is adapted to extend within the patient and a proximal
end, opposite the distal end, of each catheter is adapted to remain
outside the patient's body for cooperating with a means for
treating or purifying the fluids drawn from the patient.
[0012] In one embodiment, the catheter assembly has at least two
catheters that are approximately parallel to one another. The at
least two catheters are long enough to extend though the
subcutaneous tunnel from the exit site to the catheterized blood
vessel. The at least two catheters are formed from two independent
tubular structures. Each tubular structure has a relatively
constant wall thickness and flow cross-section across its length
and is used for facilitating simultaneous opposing fluid flow
between the patient and an exterior unit, for example, a
hemodialysis unit. Further, as the catheter assembly can be within
the patient for a significant period of time, each catheter is
sufficiently flexible to avoid discomfort, trauma, or stenosis to
the patient.
[0013] The at least two catheters of the catheter assembly are
joinable at sections along the walls of the at least two catheters
towards the distal end of the catheter. These sections may be
pre-selected or non-pre-selected distances. In one embodiment, the
catheters are joinable at pre-selected positions on generally
opposite flat facing surfaces of each of the at least two
catheters. As more sections of the catheters are joined, the
distance between the distal tips of the catheters is decreased. In
many cases, the joining of sections of the at least two catheters
allows the practitioner to control the distance between the tips at
the distal ends of the catheters, which can be used to maximize the
fluid flow and the comfort to the patient.
[0014] The means for joining the catheters of the catheter assembly
can be numerous. An illustrative example includes a joining means
such as a series of interlocking junctions, in which the elements
of each locking junction cooperate with each other to lock the at
least two lumens together. Another illustrative example includes
the use of an adhesive placed along the facing walls of the
catheters so that the at least two catheters can be joined by
pressing the facing walls of the respective catheters together.
[0015] The joinable tip configuration of the catheter assembly
allows the at least two catheters to be spaced apart from one
another a selected distance without compromising the structure and
structural integrity of each of the at least two catheters. This
ability to change the spacing between the at least two catheters
can allow the practitioner to adjust the catheter assembly to fit
different patients without affecting the function of the catheter
assembly. In a hemodialysis application, this spacing can help to
prevent mixing of the cleansed blood, which returns through one of
the at least two catheters, and the blood being removed from the
blood vessel, which leaves through another one of the at least two
catheters.
[0016] In operation and use, the catheter assembly can be used for
the removal of fluid to be purified from the patient and/or
subsequently for the reintroduction of purified fluid into patient.
Initially, the at least two catheters are supplied separated from
each other along the length of the at least two catheters an amount
equal to or preferably greater than the maximum distance
recommended for the specific procedure. Before, after or during the
installation of the catheter assembly, the practitioner then can
join the at least two catheters together along the facing walls of
the at least two catheters using the joinable means to reduce the
separation distance to the desired or required distance. In one
example, after the joining of the at least two catheters as
necessary, the catheter assembly can be installed into a patient by
ordinary medical techniques, after which the catheter assembly can
perform its function. In another example, such as in the case of
hemodialysis, after the at least two catheters have been joined and
inserted through the patient's skin into the appropriate blood
vessel (by techniques such as the Seldinger technique), blood is
channeled out of the patient through one lumen of the at least two
catheters to a purification machine and after purification the
blood is channeled back into the patient through another of the at
least two catheters.
[0017] Although embodiments of the present invention are generally
disclosed in the context of hemodialysis catheters, it is
understood that such embodiments can be applied to other catheters
that are used for procedures that require that fluid, blood,
medicated solution, or other solutions be removed and introduced
into a patient. Such procedures include, but are not limited to,
hemodialysis, perfusion, chemotherapy, and plasmapheresis.
[0018] These features and advantages of the present invention and
the complementary method for installation and use of the invention
will become more apparent to those of ordinary skill in the art
when the following detailed description of the preferred
embodiments is read in conjunction with the appended figures, in
which like reference numerals represent like components throughout
the various figures.
BRIEF DESCRIPTION OF THE FIGURES
[0019] FIG. 1 is a perspective view of one illustrative embodiment
of the present invention.
[0020] FIG. 2 is a perspective view of the distal end of the
embodiment shown in FIG. 1.
[0021] FIG. 3 is a perspective view of the distal end of a second
illustrative embodiment of the present invention.
[0022] FIG. 4 is perspective view of the distal end of a third
illustrative embodiment of the present invention.
[0023] FIG. 5 is a cross section along line 5-5' of the embodiment
shown in FIG. 1.
[0024] FIG. 6 is a sectional view of a body with the embodiment
shown in FIG. 1 placed therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Illustrative embodiments of the present invention include
multiple lumen catheter assembly 10 that has at least two joinable
catheters 12, 14 such that the distance between two of the at least
two catheters 12, 14 at a distal section or end 20 of the catheter
assembly 10 can be varied. While the invention is described herein
in conjunction with the preferred and illustrative embodiments, it
will be understood that the invention is not limited to these
embodiments.
[0026] Catheter assembly 10 comprising multiple catheters 12, 14
can be constructed in accordance with the illustrative embodiments
of the present invention as shown in FIGS. 1-6. FIG. 1 is a
perspective view of catheter assembly 10 showing the general
structure of the one illustrative embodiment in an unstressed
configuration. FIG. 2 is a perspective view of a distal section 20
of the embodiment of shown in FIG. 1 showing generally the joinable
catheters configuration. FIG. 3 is a perspective view of a distal
section 20 of another illustrative embodiment showing one means for
providing the joinable catheters configuration. FIG. 4 is a
perspective view of a distal end 20 of the embodiment another
illustrative embodiment showing another means for providing the
joinable catheters configuration. FIG. 5 is a cross-section of the
embodiment shown in FIG. 1 along line 5-5'. FIG. 6 is a sectional
view of the embodiment shown in FIG. 1 within the body of a
patient.
[0027] Catheter assembly 10 is intended for use in applications in
which bodily fluids, medicated solutions, and other solutions are
introduced into and removed from the body. For example, in the case
of hemodialysis treatment, one embodiment of the invention is
useful for the removal of blood from a patient's blood vessel for
purification and for reintroducing the blood into the patient after
purification through the same blood vessel. In such applications,
catheter assembly 10 can be used in many blood vessels including
the femoral blood vessels, subclavian blood vessels or other blood
vessels.
[0028] Referring now to FIGS. 1 and 6, catheter assembly 10 has two
ends with distinctive functions. More particularly, a distal end 20
of catheter assembly 10 is adapted to extend within a blood vessel
44 of a patient and a proximal end 30, opposite the distal end 20,
of catheter assembly 10 is adapted to remain outside the patient's
body for cooperating with a means for exchanging fluids drawn from
the blood vessel 44. Preferable, the at least two catheters 12, 14
are approximately parallel to one another and are long enough to
extend though the subcutaneous tunnel 46 from the exit site to the
catheterized blood vessel 44.
[0029] The at least two lumens 12B, 14B of the respective catheters
12, 14 are formed from two independent tubular structures. Each
tubular structure has a relatively constant wall thickness and flow
cross-section across its length and is used for facilitating
simultaneous opposing fluid flow between the patient and an
exterior unit, for example a hemodialysis unit, and back to the
patient. Each of the at least two catheters 12, 14 is preferably
constructed of a material of a sufficient rigidity to maintain its
general shape under normal usage, including instances when negative
pressure is applied to catheter assembly 10 (for example when
aspirating blood from blood vessel 44) or when positive pressure is
applied to the catheter assembly 10 (for example when introducing
blood to the blood vessel 44). Preferably, as catheter assembly 10
can be within the patient for a significant period of time, each of
the at least two catheters 12, 14 also is sufficiently flexible to
avoid discomfort, trauma, or stenosis to the patient.
[0030] As shown in FIG. 2, the at least two catheters 12, 14 of
catheter assembly 10 are joinable to each other at at least one
position along a region towards the distal end 20 of catheter
assembly 10. Preferably, the at least two catheters 12, 14 are
joinable at pre-selected points generally along the facing flat
walls 34 of each of the at least two catheters 12, 14 through
joining at least one connecting means 40. The joining of more
portions of the at least two catheters 12, 14 will decrease
distance D between the tips 16, 18 of the at least two catheters
12, 14, as well as the separated length L between the separated
lumens catheters 12, 14.
[0031] The joining of the at least two catheters 12, 14 at at least
one position allows the practitioner to control the distance D
between, and the length L of separation of, the at least two
catheters 12, 14 at the distal end 20. For example, if the
practitioner needs the tips 16, 18 at the distal end 20 of the at
least two catheters 12, 14 to be closer, the practitioner can join
more sections along the walls 34 of the at least two catheters 12,
14 by using connecting means 40. Contrastingly, if the practitioner
wants to maintain an increased distance D and/or length L at the
distal end 20 between the at least two catheters 12, 14, the
practitioner will not join as many sections of the least two
catheters 12, 14. Preferably, once the at least two catheters 12,
14 are joined, the catheters 12, 14 cannot be separated without
applying an undue force and/or destroying the structural integrity
of the catheters 12, 14. In this manner, the practitioner generally
can be assured that the catheters 12, 14 will not separate within
the patient's body.
[0032] There can be any number of connecting means 40 located along
the facing walls 34 of the at least two catheters 12, 14. However,
for ease of use, and to decrease the number of possible clotting or
coagulation sites, the use of one or two connecting means 40 is
preferred. Five such connecting means 40 are shown in FIG. 2 that
allow the joining of the at least two catheters 12, 14 at several
different lengths L. Specifically, joining connecting means 40A
results in a catheter separation distance of L1, joining connecting
means 40B results in a catheter separation distance of L2, joining
connecting means 40C results in a catheter separation distance L3,
joining connecting means 40D results in a catheter separation
distance of L4, joining connecting means 40E results in a catheter
separation distance of L5, and so on. Generally, if an outer
connecting means such as, for example, connecting means 40C is
joined, all intervening connecting means 40 such as connecting
means 40B and 40A also are joined.
[0033] Referring to FIG. 3A-3B, in one embodiment the at least two
catheters 12, 14 are joinable by connecting means 40 that can be a
series of interlocking junctions. In this embodiment, the elements
of each interlocking junction cooperate with each other to lock
sections of the at least two catheters 12, 14 together. More
particularly, as interlocking junctions can have one male element
51 and one female element 52, the practitioner can selectively join
or snap sections of the at least two catheters 12, 14 together
using male element 51 and female element 52. Preferably, once each
of the connecting means 40 is locked together, male element 51 and
female element 52 cannot be separated without applying an undue or
destructive force to the at least two catheters 12, 14, as
discussed previously, to help prevent undesirable separation of the
catheters 12, 14.
[0034] Referring to FIG. 4, another embodiment of connecting means
40 is through the use of adhesive 54. Such adhesive 54 can be a
natural or synthetic adhesive. In this embodiment, the adhesive 54
preferably is pre-positioned at certain intervals along at least
one of the walls 34 of the at least two catheters 12, 14 and the
practitioner uses the adhesive 54 to join the catheters 12, 14.
Alternatively, the adhesive 54 can be along the entire wall 34 of
at least one or two of the at least two catheters 12, 14, such that
the adhesive 54 on one wall 34 interacts with the adhesive 54 on
another wall 34, creating a tighter bond.
[0035] Other alternatives can be used. For example, a locking
zipper-type seal, such as a variation on the zipper on plastic
storage bags, can be used. One of ordinary skill in the medical
device sealing field can substitute various different locking means
for the disclosed means without undue experimentation.
[0036] As shown in FIG. 5, the at least two lumens 12B, 14B each
preferably have an approximately semi-circular or "D"-shaped cross
section. The connecting means 40 does not affect the cross
sectional shape or interior dimensions or flow pattern of the at
least two lumens 12B, 14B. More specifically, as is known in the
catheter art, each catheter 12, 14 has an inner peripheral surface
wall 36 defining the interior flow cavity 38 of the lumens 12B,
14B. When using two catheters, as shown as the illustrative example
in the FIGs., as the catheters 12, 14 generally run parallel to
each other, the generally flatter side surface walls 34 are close
to and facing one another. The connecting means 40 preferably are
located on the flatter side surface walls 34 of each catheter 12,
14. As shown, the connecting means 40 does not impact the size or
shape of the at least two lumens 12B, 14B.
[0037] It is understood that the generally semi-circular cross
section is for illustrative purposes. For example, the cross
section of catheter assembly 10 can be shaped as an oval, ellipse,
square, triangle, kidney bean, or other shapes. Further, it should
be understood that the catheters may be further subdivided and/or
additional catheter tubes of the same or varied cross sectional
configurations can be provided within the scope of the invention. A
person of ordinary skill in the art can select and configure
catheter assembly 10 with such shapes without undue
experimentation.
[0038] Referring back to FIG. 1, the at least two catheters 12, 14
can be separate or independent from each other starting at many
different points. As shown in FIG. 1, the two catheters 12, 14
shown are part of a generally unitary double catheter structure for
approximately half their total length, or until splitting point S.
Splitting point S can be at any selected distance from connecting
hub 50, but preferably should be at a maximum distance so as to
allow catheters 12, 14 to be separate and independent from each
other for a medically appropriate distance. For example, the
medically appropriate distance for a hemodialysis catheter can be
the maximum desirable distance for use in a human being in the
90%+size range. As such, the separated catheters 12, 14 could be
used as is for larger patients (those in the 90%+size range), and
the joined catheters 12, 14 could be used for smaller patients.
Alternatively, splitting point S can be at the point the catheters
12, 14 leave the connecting hub 50, meaning that catheters 12, 14
are separate and independent along their entire lengths from
connecting hub 50.
[0039] As shown, the independence of the at least two catheters 12,
14 can confer several benefits to catheter assembly 10. The
distinct surface walls 34 of each of the at least two catheters 12,
14 can add structural stability to catheter assembly 10. Further,
as the at least two catheters 12, 14 have individual walls, it is
possible to have separate lumens 12B, 14B and thus create the split
tipped structure of catheter assembly 10. Importantly, the at least
two catheters 12, 14 are in a free-floating configuration in the
same vessel to provide higher flow rates with lower pressures and
with less occlusion. The ability to change the length L of the
separation and, as a result, the separation distance D, allows the
use of the same catheter assembly 10 in many different sized
patients.
[0040] Referring now to FIG. 6, the joinable tip structure of
catheter assembly 10 allows the at least two catheters 12, 14 to be
spaced apart from one another without compromising the structure of
each of the at least two catheters 12, 14. This ability to change
the separation distance D and length L between the at least two
catheters 12, 14 allows the practitioner to adjust catheter
assembly 10 to fit different patients. In a hemodialysis
application, this spacing can help to prevent mixing of cleansed
blood returning through one of the at least two lumens with the
blood being removed from the blood vessel through another one of
the at least two lumens.
[0041] Generally, larger distances D and lengths L allow for less
mixing of fluids being returned with fluids being removed. However,
different patients have different lengths of usable blood vessels.
For example, a 6' 10" male patient typically would have a longer
usable blood vessel than a 4" 8" female patient. The joinable
feature of the present invention allows the practitioner to
compensate for such a difference.
[0042] In addition to the joinable catheters, catheter assembly 10
can have many of the features present on conventional catheters.
For example, referring back to FIG. 1, catheter assembly 10 can
have a radioplaque stripe 22 for aiding in the locating of catheter
assembly 10 by a fluoroscope. For another example, catheter
assembly 10 can have a fabric cuff 24 that is spaced accordingly to
allow for optimal and/or long-term stabilization of catheter
assembly 10 in its indwelling position. For another example,
catheter assembly 10 can have pair of clamps 26 that can be used to
secure or close off such connector tubes before and after a
procedure. Other features for optimal utilization of catheter
assembly 10 are known to those with skill in the art and can be
placed on catheter assembly 10 without undue experimentation.
[0043] The proximal ends 30 of the at least two catheters 12,14 can
be secured to a connecting hub 50. The connecting hub 50 couples
the tubular structures of the at least two catheters 12, 14 to
external portions 12A, 14A of catheters 12, 14 and for
communicating therewith. The connecting hub 50 can have a suturing
slot 60 that can be rotatably anchored to the connecting hub 50.
Such a suturing slot 60 may provide a means for stabilizing the
connecting hub 50 to the patient's skin adjacent the exit site.
[0044] In operation and use, catheter assembly 10 can be used for
the removal of fluid to be purified from and/or subsequently for
the reintroduction of purified fluid into patient. Before, after or
during the installation of catheter assembly 10, the practitioner
can join the at least two catheters 12, 14 along the walls 34 of
the at least two catheters 12, 14 using connecting means 40. In one
embodiment, after the joining of the at least two catheters 12, 14
as necessary at the appropriate point, the catheter assembly 10 can
be installed into a patient by ordinary medical techniques, after
which catheter assembly 10 can perform its function. For example,
in the case of hemodialysis, after catheter assembly 10 has been
inserted through the patient's skin into the appropriate blood
vessel 44 (by techniques such as the Seldinger technique), blood
can flow out of the patient through one lumen of the at least two
catheters 12, 14 to a purification machine and after purification,
the blood can be channeled back into the patient through another of
the two catheters 12, 14 of catheter assembly 10.
[0045] Each of the at least two catheters 12, 14 can be
manufactured to have a length and width useful for catheterization
of an intended blood vessel 44 and/or application. As shown, the
catheters 12, 14 can be longitudinally spaced by a sufficient
distance so to essentially prevent or reduce the chance for the
mixing of the blood to be removed and the blood to be reintroduced.
The optimal distance will vary for different applications and with
the patient that will be catheterized. One of ordinary skill in the
art can manufacture catheter assembly 10 without undue
experimentation.
[0046] The at least two catheters 12, 14 are made from a material
or materials that such is or are flexible, durable, soft, and
easily conformable to the shape of the area to be catheterized
and/or the subcutaneous area, and that minimize risk of harm to
vessel 44 walls. If catheter assembly 10 is used for hemodialysis
applications, it preferably is formed of a softer material that has
a hardness of at most about 85-A on a Shore durometer scale.
[0047] The at least two catheters 12, 14 can be made of
biocompatible plastics and elastomers. Such biocompatible plastics
include materials such as, for example, polyethylene, homopolymers
and copolymers of vinyl acetate such as ethylene vinyl acetate
copolymer, polyvinylchlorides, homopolymers and copolymers of
acrylates such as polymethylmethacrylate, polyethylmethacrylate,
polymethacrylate, ethylene glycol dimethacrylate, ethylene
dimethacrylate and hydroxymethyl methacrylate, polyurethanes,
polyvinylpyrrolidone, 2-pyrrolidone, polyacrylonitrile butadiene,
polycarbonates, polyamides, fluoropolymers such as homopolymers and
copolymers of polytetrafluoroethylene and polyvinyl fluoride,
polystyrenes, homopolymers and copolymers of styrene acrylonitrile,
cellulose acetate, homopolymers and copolymers of acrylonitrile
butadiene styrene, polymethylpentene, polysulfones, polyesters,
polyimides, polyisobutylene, polymethylstyrene and other similar
compounds known to those of ordinary skilled in the art. Such
biocompatible elastomers include medical grade silicone rubbers,
polyvinyl chloride elastomers, polyolefin homopolymeric and
copolymeric elastomers, urethane-based elastomers, and natural
rubber or other synthetic rubbers. One of ordinary skill in the art
can select a biocompatible material suitable for manufacturing
catheter assembly 10 without undue experimentation.
[0048] Although embodiments of the present invention are generally
disclosed in the context of hemodialysis catheters, it is
understood that such embodiments can be applied to other catheters
that are used for procedures that require that fluid, blood,
medicated solutions, or other solutions to be removed from and
introduced into a patient. Such procedures include, but are not
limited to, hemodialysis, perfusion, chemotherapy, and
plasmapheresis.
[0049] The above detailed description of the preferred embodiments,
examples, and the appended figures are for illustrative purposes
only and are not intended to limit the scope and spirit of the
invention, and its equivalents, as defined by the appended claims.
One skilled in the art will recognize that many variations can be
made to the invention disclosed in this specification without
departing from the scope and spirit of the invention.
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