U.S. patent application number 12/333940 was filed with the patent office on 2010-06-17 for anti-thrombogenic catheter and method.
This patent application is currently assigned to Cook Incorporated. Invention is credited to Cleve S. Koehler.
Application Number | 20100152698 12/333940 |
Document ID | / |
Family ID | 42241424 |
Filed Date | 2010-06-17 |
United States Patent
Application |
20100152698 |
Kind Code |
A1 |
Koehler; Cleve S. |
June 17, 2010 |
ANTI-THROMBOGENIC CATHETER AND METHOD
Abstract
A medical catheter assembly is provided including an inner
catheter member, where that inner catheter member includes a
plurality of inner catheter lumens, and an outer sheath with at
least one patent sheath lumen. The inner catheter is slidably
disposed through a length of the at least one patent sheath lumen
in a manner providing a substantially sealing contact between an
exterior surface of the inner catheter and an inward surface of the
at least one patent sheath lumen. A first of the plurality of inner
catheter lumens includes a plurality of apertures to the exterior
surface of the inner catheter, and a second of the plurality of
inner catheter lumens includes at least one distal end-tip opening.
A method of using the assembly is also provided.
Inventors: |
Koehler; Cleve S.;
(Ellettsville, IN) |
Correspondence
Address: |
BRINKS HOFER GILSON & LIONE/CHICAGO/COOK
PO BOX 10395
CHICAGO
IL
60610
US
|
Assignee: |
Cook Incorporated
Bloomington
IN
|
Family ID: |
42241424 |
Appl. No.: |
12/333940 |
Filed: |
December 12, 2008 |
Current U.S.
Class: |
604/500 ;
604/524 |
Current CPC
Class: |
A61M 25/007 20130101;
A61M 25/0017 20130101; A61M 25/003 20130101; A61M 25/0045 20130101;
A61M 25/0023 20130101; A61M 25/0026 20130101; A61M 2025/0681
20130101; A61M 2025/004 20130101 |
Class at
Publication: |
604/500 ;
604/524 |
International
Class: |
A61M 25/00 20060101
A61M025/00 |
Claims
1. A medical catheter assembly comprising: an inner catheter member
comprising a plurality of inner catheter lumens, and an outer
sheath comprising at least one patent sheath lumen; where the inner
catheter is slidably disposed through a length of the at least one
patent sheath lumen in a manner providing a substantially sealing
contact between an exterior surface of the inner catheter and an
inward surface of the at least one patent sheath lumen; a first of
the plurality of inner catheter lumens comprising a plurality of
apertures to the exterior surface of the inner catheter; and a
second of the plurality of inner catheter lumens comprising at
least one distal end-tip opening.
2. The medical catheter assembly of claim 1, wherein a selected one
of the inner catheter, the outer sheath, and a combination thereof
comprises a coating of an anti-thrombogenic material.
3. The medical catheter assembly of claim 2, wherein the
anti-thrombogenic material comprises heparin.
4. The medical catheter assembly of claim 1, wherein the plurality
of apertures is non-uniformly distributed along a distal portion of
the inner catheter.
5. The medical catheter assembly of claim 1, wherein only the first
of the plurality of inner catheter lumens comprises a plurality of
apertures open to the exterior surface of the inner catheter and
configured for fluid communication of a first therapeutic
agent.
6. The medical catheter of claim 1, wherein at least one of the
plurality of apertures comprises a non-circular geometry.
7. The medical catheter assembly of claim 1, wherein the second of
the plurality of inner catheter lumens comprising at least one
distal end-tip opening is configured for fluid communication of a
second therapeutic agent.
8. The medical catheter assembly of claim 1, further comprising a
third inner catheter lumen.
9. The medical catheter assembly of claim 8, wherein the third
inner catheter lumen comprises a plurality of apertures to the
exterior surface of the inner catheter, said apertures configured
to be sealingly covered by an inward surface of the at least one
patent sheath lumen.
10. The medical catheter assembly of claim 8, wherein the third
inner catheter lumen comprises a second distal end-tip opening.
11. The medical catheter assembly of claim 1, further comprising a
first proximal catheter structure and a second proximal catheter
structure, each having a longitudinal lumen, wherein the first of
the plurality of inner catheter lumens is in fluid communication
with a first proximal catheter structure lumen and the second of
the plurality of inner catheter lumens is in fluid communication
with a second proximal catheter structure lumen.
12. The medical catheter assembly of claim 11, wherein a portion of
at least one of the proximal catheter structures comprises visual
indicia configured to distinguish it from another of the proximal
catheter structures.
13. A medical catheter assembly configured for use as an indwelling
central venous catheter and comprising: an elongate inner catheter
body comprising: a central first lumen including a distal end-tip
opening; an outer second lumen; and wherein a plurality of
apertures opens from the outer second lumen to an exterior surface
of the elongate inner catheter body to provide a path of fluid
communication; an outer sheath comprising a sheath lumen through
which at least a portion of the elongate inner catheter body is
slidably disposed; wherein a surface of the sheath lumen sealingly
contacts the exterior surface of the elongate catheter body such
that fluid communication through any of the plurality of apertures
is substantially prevented for apertures covered by the outer
sheath.
14. A method for installing a catheter, the method comprising the
steps of: providing a catheter assembly according to claim 1;
directing the assembly into proximity with a blood vessel; further
directing the inner catheter member through a wall of the blood
vessel into a vessel lumen thereof, and further directing the outer
sheath into close proximity with the blood vessel such that
substantially none of the plurality of inner catheter apertures are
open outside the blood vessel, said inner catheter apertures being
open into the vessel lumen or sealingly covered by the outer
sheath; directing a first therapeutic agent though the first inner
catheter lumen and at least one inner catheter aperture; and
directing a second therapeutic agent through the second inner
catheter lumen.
15. The method of claim 14, wherein the step of providing a
catheter assembly further comprises aligning distal ends of the
inner catheter member and the outer sheath.
16. The method of claim 14 further comprising a step of directing a
distal portion of the outer sheath into the blood vessel.
17. The method of claim 16 further comprising a step of
longitudinally adjusting the position of the inner catheter
relative to the outer sheath in a manner controlling the number of
apertures not covered by the outer sheath.
18. The method of claim 14, wherein the catheter assembly is
dimensioned for use as a central venous catheter, and the blood
vessel is selected from one of a subclavian vein, a femoral vein,
and a jugular vein.
19. The method of claim 14, wherein at least one of the therapeutic
agents is an anti-thrombotic agent.
20. The method of claim 14, wherein each of a first sub-plurality
of the apertures comprises a different surface area than each of a
second sub-plurality of the apertures.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to medical catheter
devices and more particularly to indwelling catheters and methods
related to same.
BACKGROUND
[0002] An indwelling catheter (e.g., central venous catheter)
commonly is placed into a central blood vessel of a patient
undergoing medical treatment for prolonged, long-term, or chronic
conditions. The catheter provides for infusion of therapeutic
materials such as, for example, chemotherapy agents. The presence
of an indwelling catheter often increases the risk of deep vein
thrombosis (DVT), which is the formation of a blood clot (thrombus)
in a deep vein. Although the causes of DVT are not well understood,
it may occur as a result of turbulence or other disruption in blood
flow caused by the catheter. The blood clot may become dislodged
(at which time it is termed an embolus) and move through venous
circulation to another location in the body. This is particularly
serious if the embolus is transported through venous circulation
to, and through, the heart, where it can become lodged with and
block a pulmonary artery. This blockage of blood flow to a region
of the lungs can cause permanent lung damage or death. If the
embolus lodges elsewhere in the body, for example where it impedes
or blocks blood flow in a muscle of an extremity, it can cause
extreme pain and permanent tissue damage.
[0003] In many patient populations, so-called blood-thinners (e.g.,
warfarin, heparin) are introduced systemically when an indwelling
catheter is present in order to decrease the risk of DVT. However,
there are significant potential side effects from such treatment
including increased risk of bleeding and hemorrhage. These risks
may be even greater for patients suffering from conditions where
use of an indwelling catheter is indicated.
[0004] Pediatric patients are often at risk of DVT in conjunction
with an indwelling catheter. However, the risk of DVT in pediatric
patients is generally low enough that the risk of side effects from
use of blood-thinners outweighs the risk of embolus formation and
blood-thinners are not used as commonly as in, for example,
geriatric patients. The risk-balancing calculus associated with
these facts must also take into account that DVT is considered more
serious in pediatric patients because they have the opportunity to
live an entire life span of 60-80 years after a pediatric DVT
incident, and the damage done by an embolus can have crippling long
term effects on development and quality of life. Of course,
improved long-term quality of life and reduced risk of DVT is
important for patients of any age.
[0005] For this reason, it is desirable to provide an indwelling
catheter and method of use that may reduce the risk of DVT
associated with use of an indwelling catheter. One such approach
has used heparin impregnated in polymers of a catheter itself or
applied to its surface. This approach is useful, but there may also
be a need for adjustable control or user-selectable
location-targeting of an anti-DVT agent, which may also be
desirable to provide treatment tailored for individual patients
based upon age and other specific indications for treatment.
BRIEF SUMMARY
[0006] In one aspect, a medical catheter assembly may include an
inner catheter member, where the inner catheter member includes a
plurality of inner catheter lumens, and an outer sheath with at
least one patent sheath lumen. The inner catheter may be slidably
disposed through a length of the at least one patent sheath lumen
in a manner providing a substantially sealing contact between an
exterior surface of the inner catheter and an inward surface of the
at least one patent sheath lumen. A first of the plurality of inner
catheter lumens may include a plurality of apertures to the
exterior surface of the inner catheter, and a second of the
plurality of inner catheter lumens may include at least one distal
end-tip opening.
[0007] In another aspect, a medical catheter assembly may be
configured for use as an indwelling central venous catheter and
include an elongate inner catheter body and an outer sheath. The
elongate inner catheter body may include a central first lumen
including a distal end-tip opening, an outer second lumen, and a
plurality of apertures open from the outer second lumen to an
exterior surface of the elongate inner catheter body. The outer
sheath may include a sheath lumen through which at least a portion
of the elongate inner catheter body is slidably disposed, wherein a
surface of the sheath lumen sealingly contacts the exterior surface
of the elongate catheter body such that fluid communication through
any of the plurality of apertures is substantially prevented for
apertures covered by the outer sheath.
[0008] In another aspect, a method for installing a catheter may
include the steps of: providing a catheter assembly as described
herein, directing the assembly into proximity with a blood vessel,
further directing the inner catheter member through a wall of the
blood vessel and into a vessel lumen thereof, and further directing
the outer sheath into close proximity with the blood vessel such
that substantially none of the plurality of inner catheter
apertures are open outside the blood vessel, said inner catheter
apertures being open into the vessel lumen or sealingly covered by
the outer sheath, directing a first therapeutic agent though the
first inner catheter lumen and at least one inner catheter
aperture, and directing a second therapeutic agent through the
second inner catheter lumen.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 shows a first embodiment of a catheter assembly;
[0010] FIG. 2 shows a transverse cross-sectional view of the
catheter assembly of FIG. 1 taken along line 2-2;
[0011] FIG. 3 shows a second embodiment of a catheter assembly;
and
[0012] FIGS. 3A, 3B, and 3C show, respectively, alternative
transverse cross-sectional views (taken along line 3-3) of
different embodiments of the catheter assembly shown in FIG. 3.
DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERRED
EMBODIMENTS
[0013] FIG. 1 shows one embodiment of a medical catheter assembly
100. The catheter assembly 100 includes an inner catheter member
102 and an outer sheath 104. The inner catheter 102 is slidably
disposed through a lumen of the outer sheath 104 so that it can be
withdrawn into and extended out from it. The slidable relationship
includes providing a substantially sealing contact between the
exterior surface of the inner catheter 102 and an inward surface of
the lumen of the outer sheath 104, which preferably is fluid-patent
(i.e., fluid is prevented from traveling out of any apertures
covered by the sheath). The outer sheath 104 may also have other
lumens, which may or may not be fluid-patent including, for
example, a wire guide lumen.
[0014] The inner catheter 102 includes a plurality of apertures 106
along its external surface and a distal end-tip opening 108. In the
embodiment shown in FIG. 1, the distal end is slightly tapered so
as to be rounded, but those of skill in the art will appreciate
that the distal end may be more or less gradually tapered, blunt,
or incorporating some other geometry, all within the scope of the
present invention.
[0015] FIG. 2 shows a magnified transverse section view along line
2-2 of FIG. 1. As shown in FIG. 2, the inner catheter 102 includes
an outer first lumen 112 and a second central lumen 114. The
apertures 106 shown in FIGS. 1 and 2 provide external fluid
communication for the outer lumen 112 so that fluid can exit the
outer lumen through any apertures 106 that are not covered by the
outer sheath 104. In one embodiment, more distal apertures 106 may
be larger than more proximal apertures 106 in a manner that may
provide consistent fluid flow therethrough along the inner catheter
length as fluid pressure may change as some fluid is released
through more proximal apertures. In various embodiments, the size
of apertures along the catheter length may be made larger or
smaller to vary/control flow rate in a desired manner along
predetermined regions of the catheter length. FIG. 2 includes two
outer lumens 112 that are generally symmetrical to each other and
that may be open to (i.e., in fluid communication with) each other.
Other embodiments may include one outer lumen open to the apertures
106 or a plurality of two or more outer lumens, which may be
symmetric or asymmetric in cross-section and relative to each
other.
[0016] It is preferable that the apertures 106 be generally
uniformly distributed around the outer circumference of the inner
catheter 102, but some embodiments may have
asymmetrically/nonuniformly distributed apertures. Specifically, a
greater or lesser density of apertures 106 may be provided more
proximally, centrally, or distally along the portion of the inner
catheter 102 having those apertures, and/or the apertures may be
uniformly or non-uniformly distributed around the catheter
circumference. In preferred embodiments, the apertures 106 will be
dimensioned to allow efficient low-level flow of an anti-clotting
agent in a concentration effective to decrease risk of thrombus
formation in the region of the catheter assembly. For example, the
diameter of circular apertures may be about 0.1 mm to about 1 mm,
with a diameter range of about 0.3 mm to about 0.5 mm in certain
embodiments. The apertures may be circular, obround, oval,
elliptical, polygonal or any other shape effective to release the
desired compound. It is preferable that the dimensions and geometry
of the apertures provide for sufficiently low-level flow that a
minimum effective concentration of the anti-clotting agent is used
for the purpose of minimizing potential undesired side effects. As
another example, more proximal apertures may have a different shape
and/or different surface area than more distal apertures (see,
e.g., FIG. 3). In some embodiments, the catheter assembly may be
dimensioned for use in treatment of pediatric patients. Preferred
embodiments will be constructed of biocompatible polymers such as,
for example, ePTFE, polyurethane, silicone, or other polymers,
preferably including polymers having a low-friction surface. In
certain embodiments, an anti-thrombogenic/anti-clotting agent such
as, for example, heparin, may be bonded to the exterior of the
inner catheter and/or the sheath (see, e.g., U.S. Publ. Pat. App.
2005/0100580, Cook, Inc., Bloomington, Ind., which is incorporated
herein by reference in its entirety).
[0017] The inner lumen 114 and its distal opening 108 preferably
are dimensioned to provide for effective introduction to a patient
of a therapeutic material such as, for example, nutrient fluids,
chemotherapeutic agents, therapeutic drugs, whole blood, blood
plasma, and/or other materials.
[0018] FIG. 1 also shows one example of a proximal structure,
embodied as a dual-catheter hub structure 150, that may be used to
provide a user interface with the device 100. The hub structure 150
includes a proximal first catheter 152 and a proximal second
catheter 154. Each of the catheters 152,154 includes a connection
hub 156 (such as, for example, a luer-type hub or other fluid-tight
access means that preferably provides for quick, easy
connection/disconnection) at its proximal end. The proximal first
catheter 152 provides a patent lumen in fluid communication with
the outer first lumens 112 of the inner catheter 102. The proximal
second catheter 154 provides a patent lumen in fluid communication
with the inner second lumen 114 of the inner catheter 102. In one
preferred embodiment, one or both of the proximal catheters will
include visual and/or tactile indicia for a user readily to
distinguish them from each other (such as, for example, banding,
color coding, text labeling, differing sizes, differing geometric
shapes, etc., or any combination thereof). The proximal structure
may also include clips (such as, for example, the clips 158, or any
other clip configuration). Those of skill in the art will
appreciate that other configurations of the proximal structure used
in existing indwelling catheter devices and other devices, as well
as configurations presently known or developed in the future, may
be used within the scope of the present invention.
[0019] FIG. 3 shows another embodiment of a medical catheter
assembly 300. The catheter assembly 300 includes an inner catheter
member 302 and an outer sheath 304. The inner catheter 302 is
slidably disposed through a lumen of the outer sheath 304 so that
it can be withdrawn into and extended out from it. The slidable
relationship includes providing a substantially sealing contact
between the exterior surface of the inner catheter 302 and an
inward surface of the lumen of the outer sheath 304, which
preferably is fluid-patent (i.e., fluid is prevented from traveling
out of any apertures covered by the sheath). The outer sheath 304
may also have other lumens, which may or may not be fluid-patent
including, for example, a wire guide lumen.
[0020] The inner catheter 302 includes a plurality of apertures 306
along its external surface and a distal end-tip opening 308. In the
embodiment shown in FIG. 3, the distal end is slightly tapered so
as to be at least slightly rounded (presenting an atraumatic distal
profile), but those of skill in the art will appreciate that the
distal end may be more or less gradually tapered, blunt, or
incorporating some other geometry, all within the scope of the
present invention.
[0021] The apertures 306 shown in FIG. 3 provide external fluid
communication for the outer lumens so that fluid can exit the outer
lumen through any of the outer lumen apertures 306 that are not
covered by the outer sheath 304. In one embodiment, more distal
apertures 306 may be larger than more proximal apertures 306 in a
manner that may provide consistent fluid flow therethrough along
the inner catheter length as fluid pressure may change as some
fluid is released through more proximal apertures.
[0022] FIGS. 3A, 3B, and 3C represent different possible
embodiments of the catheter assembly 300, shown in cross-section
views taken along line 3-3 of FIG. 3. In FIG. 3A, the inner
catheter 302 includes a single outer first lumen 312 and a central
second lumen 314.
[0023] In the embodiment shown in FIG. 3B, the inner catheter 302
includes three outer first lumens 322, 323, 324 and a central lumen
314. Those of skill in the art will appreciate that one or more of
the outer first lumens may not include any side apertures, but may
include one or more distal end-tip openings. The tapered distal end
of the inner catheter 302 includes a distal aperture 313 providing
fluid communication from the outer first lumen 322. Such an
embodiment will provide a patent path that may be used, for
example, for passage of a wire guide, introduction of a
radio-opaque contrast fluid, introduction of another therapeutic
material in addition to (either simultaneously with, or at a
different time than) the first therapeutic material being
introduced through the central lumen, or other application.
However, within the scope of the present invention, at least one of
the outer lumens will include a plurality of distal apertures
providing fluid communication from one of the outer lumens to the
exterior of the inner catheter, but sealable by being covered by
the outer sheath.
[0024] FIG. 3C shows a transverse section view of dual-lumen
embodiment. The inner catheter includes two inner lumens 314 and
two outer lumens 312. The outer lumens 312 preferably include one
or more apertures 306. The dual inner lumens 314 may be used for
different or similar purposes relative to each other in one or more
manners, including as described above.
[0025] Those of skill in the art will appreciate that the
embodiments described above may have multiple applications. One
preferred use will include configuration for placement as a central
venous catheter and effective delivery of a therapeutic agent
through the central lumen, while providing a low dosage of an
anti-thrombogenic agent (e.g., an anti-coagulant such as, for
example, warfarin or heparin). The low dosage preferably will be a
minimum level effective to prevent thrombus formation in the
vicinity of, and/or related to the presence of, the catheter
assembly in the patient. In some embodiments, the apertures
permitting delivery of anti-thrombogenic agent(s) from the outer
lumen(s) may be configured for uni-directional flow, and/or may be
configured to minimize the likelihood of--or even prevent--entry of
a significant blood volume into the outer lumen(s). Means for
providing these features are known in the art including, for
example, providing a low-flow pucker-type valve formed in one or
more of the apertures and/or providing apertures that are
sufficiently small to allow passage of a low-viscosity solution of
anti-thrombogenic agent, but not to allow easy passage of a more
viscous and/or particulate-containing fluid such as blood. As is
described below with reference to methods of the present invention,
embodiments of a catheter assembly of the present invention may
permit location-targeting for delivery of anti-thrombogenic
agents.
[0026] A method of use is discussed here with reference to the
catheter assembly 100 illustrated in FIGS. 1-2. In a method for
installing a catheter, the catheter assembly 100 is directed in a
patient body to a location adjacent a blood vessel (such as, for
example, a jugular vein, subclavian vein, brachial vein, basilica
vein, or femoral vein). The inner catheter 102 may then be extended
out of the distal sheath end and directed into the lumen of the
blood vessel. During installation, the catheter assembly 100 may
configured with the inner catheter 102 withdrawn into the sheath
104, preferably such that the distal ends thereof are generally
aligned. In some embodiments, the sheath 104 may include or be
directed through a penetrating member (such as, for example, a
needle--not shown) to facilitate directing the assembly 100 to the
blood vessel.
[0027] The sheath 104 may remain outside the blood vessel with its
distal end adjacent thereto. Preferably, this configuration will
expose only the inner catheter apertures 106 that are within the
blood vessel lumen, which will prevent the loss of
anti-thrombogenic agent therethrough into the space around the
blood vessel. More importantly, this feature allows use of a single
catheter assembly design, the length of which can selectably be
configured for different patients based upon size and anatomy,
and/or to target delivery of one or more therapeutic materials. As
one example of an advantage presented by the present design, dosage
quantity of the anti-clotting agent may be controlled in part by
adjusting the length of the catheter portion with exposed apertures
in the blood vessel. As another example, the length to be extended
in a patient blood vessel can also be controlled. This is in
contrast with other indwelling catheter designs that commonly are
available in pre-determined sizes that do not allow the flexibility
of placement permitted with the present design, a feature that will
be evident to those of skill in the art from the method described
above.
[0028] In another alternative method (not shown), the sheath and
inner catheter may both be introduced into a blood vessel or other
body lumen. Thereafter, the number of exposed apertures (and
resulting flow/concentration of an agent being introduced
therethrough) may be modulated by the distance to which the inner
catheter is extended out of the distal end of the outer sheath.
[0029] The figures illustrating the device embodiments described
above are not intended to be to scale, and should not be construed
as limiting with regard to any dimension, proportion, or
combination. Those of skill in the art will appreciate that many
embodiments not described herein may be practiced within the scope
of the present invention. It is therefore intended that the
foregoing detailed description be regarded as illustrative rather
than limiting, and that it be understood that the following claims,
including all equivalents, are intended to define the spirit and
scope of this invention.
* * * * *