U.S. patent application number 13/068748 was filed with the patent office on 2011-09-15 for catheter retention assembly and method of use.
Invention is credited to William M. Appling, Theodore J. Beyer, Joel E. Perchik.
Application Number | 20110224618 13/068748 |
Document ID | / |
Family ID | 39102287 |
Filed Date | 2011-09-15 |
United States Patent
Application |
20110224618 |
Kind Code |
A1 |
Perchik; Joel E. ; et
al. |
September 15, 2011 |
Catheter retention assembly and method of use
Abstract
A catheter retention assembly and method of use with a catheter.
The assembly has a carrier system and a cuff positioning device
with an in-growth cuff and a lumen having an inner wall adapted to
be mounted on the outer surface of the catheter, and a carrier
system with an inner surface and an outer surface in contact with
the inner wall of the cuff positioning device. The carrier system
holds the lumen in a first radial state. When the carrier system is
removed, the lumen contracts to a second radial state, and the
inner wall of the cuff positioning device provides sufficient
surface adherence to the outer surface of the catheter, so as to
maintain the position of the cuff positioning device relative to
the catheter, and to allow for catheter exchange.
Inventors: |
Perchik; Joel E.; (Jackson,
TN) ; Appling; William M.; (Granville, NY) ;
Beyer; Theodore J.; (Queensbury, NY) |
Family ID: |
39102287 |
Appl. No.: |
13/068748 |
Filed: |
May 19, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11506505 |
Aug 18, 2006 |
7947019 |
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13068748 |
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Current U.S.
Class: |
604/175 |
Current CPC
Class: |
A61M 25/0194 20130101;
A61M 25/10 20130101 |
Class at
Publication: |
604/175 |
International
Class: |
A61M 25/04 20060101
A61M025/04 |
Claims
1-18. (canceled)
19. A method of retaining the position of a catheter having a
distal end, wherein the method comprises: a) providing a catheter
retention assembly that comprises a cuff positioning device having
an in-growth cuff and a lumen having an inner wall adapted to be
mounted on the catheter, and a carrier system with an inner surface
and an outer surface, wherein the outer surface is in contact with
the inner wall of the cuff positioning device, b) inserting the
catheter into a skin incision site, c) positioning the distal end
of the catheter at a desired location, d) moving the cuff
positioning device to a desired location, and e) removing the
carrier system from the lumen, so as to fix the position of the
catheter and the cuff positioning device relative to one
another.
20. The method of claim 19, further comprising providing a
resilient cuff positioning device.
21. The method of claim 19, further comprising holding the lumen of
the cuff positioning device in a first expanded radial state with
the carrier system.
22. The method of claim 21, further comprising contracting the
lumen of the cuff positioning device to a second radial state.
23. The method of claim 20, further comprising applying a radially
compressive force around the lumen of the cuff positioning device
using a spring.
24. The method of claim 23, further comprising manually pulling in
opposite directions at least two abutting carrier system finger
tabs along a longitudinal splittable line, away from the cuff
positioning device and retracting the carrier system.
25. The method of claim 24, further comprising securing the cuff
positioning device to a patient's skin using a securing means.
26-31. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT
DISC
[0004] Not Applicable
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] The present invention relates to the field of vascular
access devices, and more particularly, to devices and methods for
positioning and retaining long-term vascular access catheters.
[0007] 2. Description of the Related Art Including Information
Disclosed Under 37 CFR 1.97 and 1.98
[0008] Vascular access catheters provide venous access to the
central circulatory system of a patient. Vascular access catheters
placed for a short time period, typically less than two weeks, are
called acute catheters. For those medical conditions requiring long
term access to the circulatory system, chronic or permanent
vascular access catheters are used. These catheters are designed to
remain within the patient for indefinite periods, often more than a
year. Permanent or chronic venous access catheters are usually
placed through a subcutaneous tunnel and include central venous
catheters, dialysis catheters, peritoneal catheters, and
peripherally inserted central catheters, also known as PICC
lines.
[0009] The long-term catheter is typically used for the delivery of
intravenous fluids, medications such as chemotherapy drugs and
antibiotics, and blood products. Venous access catheters may also
be used as access mechanisms for blood sampling and the
administration of contrast agents during diagnostic Computer
Tomography (CT) procedures. Dialysis catheters are used to access
the venous system during hemodialysis, a medical procedure used to
cleanse the blood of patients whose kidneys do not function
properly.
[0010] Vascular access catheters are placed within the central
circulatory system such that the catheter tip is exposed to high
rate blood flow, typically in the right atrium. This allows rapid
delivery and dilution of drugs into the bloodstream, and thus, more
effective treatment. In the case of dialysis catheters, high flow
rates provide faster and more effective blood cleansing. Optimal
location of the catheter tip in a large blood vessel is also
necessary in order to decrease the rate of catheter occlusion.
[0011] Another clinical requirement of vascular access catheters is
that the catheter be placed so as to eliminate any dislodgement or
movement of the catheter during long-term use. Catheter movement
may result in sub-optimal treatment due to catheter tip
misalignment. Movement may also result in catheter leakage,
infection and blood loss. Dislodgement of a vascular access
catheter may even result in death, due to extensive blood loss from
the jugular of other large vein.
[0012] To fix and retain the position of a long-term catheter in a
patient's body, the catheter is typically inserted by tunneling the
catheter through a subcutaneous tissue track. This tunneling
technique may decrease infection rates at the site of cutaneous
insertion, which is the primary site of entry for microorganisms on
a catheter. Studies have shown that compared to standard catheter
placement, tunneling decreases bacteria colonization.
[0013] To create a subcutaneous tunnel, a first incision is made in
the patient's skin approximately several inches away from where the
catheter will enter the target vein. A second incision is made at
the location where the catheter will enter the vein. A tunnel track
is created through the facial tissue between the two incisions. The
distal end of the catheter is then inserted into the first incision
and advanced through the tunnel track where it emerges from the
skin at the second incision, or exit site. The distal portion of
the catheter is then inserted into the target vein.
[0014] Dialysis catheters are typically tunneled through the chest
wall tissue, entering the internal jugular vein at the neck area.
They may also be placed in the subclavian vein just below the
collar bone. Peritoneal catheters are tunneled from the peritoneum
to the exit site of the catheter, near the navel. As with standard
dialysis catheters, the main consideration with peritoneal
catheters is the potential for infection at the exit site or
peritonitis.
[0015] PICC lines, smaller in diameter, are typically introduced
through the basilic or cephalic vein into the central circulatory
system. Although traditionally PICC lines have been inserted
directly into the target vein, placing PICC lines through a
subcutaneous tunnel is an emerging trend. For these lines, the
tunnel is usually created in the lower or upper arm region, with
the catheter entering the target vein near the shoulder. Central
venous catheters are larger in diameter than PICC lines and are
typically placed when no peripheral veins are available, when
medications cannot be introduced into a peripheral vein without
vessel damage, or when central venous pressure monitoring is
required. Tunneling of a central venous catheter is similar to the
technique used for dialysis catheters.
[0016] Tunneled catheters may include a circular in-growth cuff
attached to the outer surface of the catheter shaft near a
bifurcation hub. The in-growth cuff is made of a porous or fibrous
material which promotes tissue in-growth by allowing the tunnel
track tissue to grow into the in-growth cuff material. The
in-growth cuff thus acts as an anchor to help secure the catheter
in place and prevent movement of the catheter. The in-growth cuff
also helps to provide protection against infections related to
vascular access catheters by sealing the tunnel track. The
in-growth cuff prevents undesired movement and inadvertent removal
of the catheter and thereby prevents excessive blood loss or death.
Because it takes approximately two weeks for tissue to become fully
incorporated into the in-growth cuff, the physician typically fixed
the catheter to the patient's skin immediately after insertion. The
catheter may be securely fixed to the patient's skin by sutures
stitched through suture wings on the hub. Alternatively, an
adhesive bandage or other skin attachment mechanism may be
used.
[0017] To optimize treatment results, the distal tip of the
catheter must be precisely placed in a large blood vessel such as
the right atrium, and the in-growth cuff must be positioned and
fixed inside of the patient's body. Positioning the catheter within
the right atrium provides the high blood flow rates required for
efficient dialysis, or in the case of PICCs, rapid delivery and
dilution of drugs into the bloodstream, and thus more effective
treatment. Optimal location of the catheter tip in a large blood
vessel is also necessary in order to decrease the rate of catheter
occlusion. Optimal placement of the catheter tip will make the
catheter tip less likely to contact or rest up against the inside
of a blood vessel wall, thereby blocking catheter ports, or causing
damage to the vessel wall from the catheter.
[0018] Optimal catheter cuff placement is critical for secure
fixation of the catheter over long periods of time. It is generally
accepted that the ideal cuff placement is at a depth of at least 2
cm to approximately 3.5 cm from the incision entry site. This
position provides for optimal in-growth of the cuff and secure
fixation. Proper catheter cuff placement also ensures a tight seal
between the catheter and the tunnel track, thereby reducing risk of
infection, and associated complications. Cuffs placed too close to
the incision site will result in sub-optimal fixation and the
increased risk of peri-catheter leakage and infection. If the
physician is forced to place the cuff deeper into the tunnel track
than desired in order to achieve optimal catheter tip placement,
catheter removal or exchange becomes problematic as it is difficult
to remove a cuff that too deeply tunneled. Studies have also shown
that deep tunneling may lead to increased risk of catheter
infection.
[0019] Patient comfort is directly related to the position of the
cuff because cuff position determines where the catheter will be
sutured to the patient's body. Most venous access catheters include
a suture wing component attached directly to the bifurcation hub.
Suturing the catheter in a less than optimal location on the
patient's body may not only lead to discomfort but may also
increase the risk of catheter movement or dislodgement. For
example, if a catheter is sutured to a female's chest, the natural
movement of the breast may compromise catheter fixation.
[0020] If optimal cuff placement cannot be achieved, the physician
may not be able to utilize the suture wings for securement to the
patient's skin. Instead, the physician may be forced to suture the
catheter to the skin surface at a location distant from the suture
wings. To do this, the physician will wrap the suture directly
around the catheter shaft at the desired location. Although this
method may achieve temporary fixation of the catheter until cuff
in-growth occurs, it may compromise the catheter's lumen due to
compression by the suture line. Reduced lumen diameter will result
in reduced flow rates through the catheter, which in turn, will
compromise treatment.
[0021] In summary, the difficulty associated with placement of the
catheter tip and the catheter cuff is that the catheter tip and the
cuff are fixed relative to each other. Thus, optimum positioning of
one is likely to result in less than optimal positioning of the
other, resulting in problems associated with treatment efficiency,
catheter fixation, infection risk, patient comfort and comprised
flow rates, as described above. Thus, there exists a need in the
art to be able to independently position the tip and cuff during a
tunneled catheter placement to ensure optimal positioning of all
elements of the catheter.
[0022] Several different types of catheters have been developed in
an attempt to address the need for precise positioning and
maintenance of the catheter tip and cuff during catheter placement.
For example, manufacturers of some vascular access catheters offer
catheters of varying lengths to accommodate different patient
anatomy and placement preferences. The catheter length requirement
for catheter tip placement at the junction of the superior vena
cava and right atrium is typically estimated by measuring the
distance of the path from the tunneled insertion site to the right
atrium. The appropriate length catheter is then selected by the
physician. Commercially available catheter lengths often only
approximate the ideal length, requiring the physician to adjust
placement of the catheter, which may result in sub-optimal
positioning. In addition, even if the overall length of a catheter
is available, the desired distance between the cuff and tip varies
by patient anatomy. To address this problem, physicians may
customize the catheter by trimming the distal end of the catheter
prior to placement. Distal trimming is disadvantageous for several
reasons. Trimming requires additional physician time to accurately
measure and trim the catheter. Trimming the catheter may increase
the chance of error in achieving the proper length and overall
placement of the catheter. Trimming the end of the catheter can
result in unwanted sharp edges, and the modified distal tip may
hinder catheter advancement through the tunnel and into the
vascular system. Trimming can also weaken the integrity of the
catheter, thus compromising treatment efficiency or increasing the
risk of shaft breakage. Additionally, some vascular access
catheters have distal tips that are tapered or otherwise uniquely
shaped and accordingly cannot be trimmed at all.
[0023] Several different types of catheters have been proposed to
address the need for accurate catheter placement by first placing
the catheter within the central venous system and then trimming the
proximal end of the catheter shaft. The distal tip of the catheter
is first placed in the desired location and then the proximal
portion of the shaft extending outside of the patient's body is
trimmed, after which a bifurcation or other hub configuration is
attached to the proximal shaft end by the physician. Trimming the
catheter proximally exposes less of the catheter to potential
damage and ensures precise positioning of both the proximal and
distal ends of the catheter, but there are key disadvantages to
this technique. Typically, the cuff is permanently pre-attached to
the catheter shaft and therefore cannot be adjusted independently
of the catheter tip. This technique is also disadvantageous in that
it requires the physician to perform additional steps to attach the
hub after initial catheter placement, thereby increasing procedure
time. Mechanically attaching a hub to a catheter shaft also
increases the potential for leakage at the hub connection and
presents concerns about the long-term structural integrity of the
attached components.
[0024] Another type of commercially available device facilitates
precise positioning of both the distal and proximal ends of the
catheter by use of an attachable suture wing connector that may be
mounted separately onto the catheter shaft. This design provides
for adjustable positioning of the suture wing, but does not provide
for independent customization, of the cuff position. In addition,
the suture wing is not permanently affixed to the catheter shaft
and thus may be inadvertently moved or even removed, resulting in
the problems associated with sub-optimal catheter fixation.
[0025] There has not been proposed a catheter assembly that
addresses the need for optimally and permanently customizing the
position of the catheter cuff and the catheter tip relative to one
another in a patient body during catheter placement. The present
invention addresses this need by utilizing a catheter retention
assembly comprised of a cuff positioning device with an in-growth
cuff and a securing means. The device includes a carrier system
which, when mounted on a vascular access catheter, is slidably and
longitudinally moveable along the catheter shaft. Once the catheter
retention assembly is positioned as desired relative to the distal
tip of the catheter, the cuff positioning device may be permanently
fixed to the catheter shaft, thus providing a means for customizing
the cuff position relative to the tip position. Once the cuff
positioning device is locked in place on the catheter shaft, the
catheter will not move or slip in relation to the cuff positioning
device. Since a securing means is also mounted on the cuff
positioning device, the physician is able to temporarily fix the
exposed catheter in the desired location on the patient's skin
until in-growth of the cuff has been established.
[0026] The combined design features of the current invention are
not presently available in conventional catheters with
fixed-position sutures and cuff assemblies. Using the device of the
current invention to independently optimize cuff and tip placement
eliminates problems with prior art devices and methods, including
the problems of sub-optimal treatment outcomes, increased infection
risk, compromised catheter integrity, insecure fixation and patient
discomfort. The instant invention may be applied to all types of
vascular access catheters, including, but not limited to,
hemodialysis catheters, peritoneal catheters, PICC lines, central
venous catheters, and tunneled catheters, as described.
[0027] Accordingly, it is a purpose of the present invention to
provide a catheter retention assembly, which provides for optimal,
simultaneous, and permanent positioning of the catheter tip and the
catheter cuff relative to one another during catheter placement by
positioning the catheter tip and fixing the position of the cuff
positioning device around the catheter. This enhanced permanent
optimal placement will improve treatment outcomes and help lower
the risk of infection in a patient, thereby enhancing the
catheter's antimicrobial properties and ensuring that the lumen of
the catheter is not compromised.
[0028] A further purpose of this invention is to provide a catheter
retention assembly that will help to ensure that adjustment of the
cuff automatically positions the external fixation mechanism such
as a suture wing in the desired place on the patient's skin away
from sensitive areas to ensure patient comfort, while not
compromising the integrity of the catheter.
[0029] A further purpose of this invention is to provide a catheter
retention assembly and method of placement that minimizes
procedural steps and provides the physician with a simple, easy to
use method of adjusting the location of a cuff without additional
catheter assembly or trimming steps.
[0030] A further purpose of this invention is to provide an
expander sheath that may be mounted around the shaft of a catheter
and may be inserted between the inner wall of the cuff positioning
device and the outer wall of the catheter shaft in order to allow
the catheter to be exchanged with anew catheter, without removing
the cuff.
[0031] Various other objectives and advantages of the present
invention will become apparent to those skilled in the art as more
detailed description is set forth below. Without limiting the scope
of the invention, a brief summary of some of the claimed
embodiments of the invention is set forth below. Additional details
of the summarized embodiments of the invention and/or additional
embodiments of the invention may be found in the Detailed
Description of the Invention.
BRIEF SUMMARY OF THE INVENTION
[0032] The present invention provides for a catheter retention
assembly that may be used to fix and retain the position of a
catheter tip and a catheter cuff, thereby providing enhanced
optimal catheter placement.
[0033] The present invention is advantageous in view of current
catheters because it provides simultaneous optimal permanent
placement of a catheter tip and a moveable catheter cuff within a
tunneled track that are independent of each other. The present
invention is also advantageous because it eliminates problems
presented by current catheters with sub-optimal cuff placement,
which can result in increased tunnel track infections and catheter
movement or dislodgement. The present invention also overcomes
problems of current catheters that require suturing the catheter to
the patient in an undesirable location of a patient's anatomy.
[0034] The present invention solves these problems by providing a
catheter retention assembly for use with a catheter that has a
through lumen adapted for coaxial arrangement on a catheter shaft.
The catheter retention assembly has a cuff positioning device, an
in-growth cuff on the cuff positioning device, and a carrier system
with an inner surface that surrounds the shaft of the catheter and
an outer surface that is in contact with the inner wall of the cuff
positioning device. When the carrier system is removed or
activated, a sufficient surface adherence is created between the
inner wall of the cuff positioning device and the outer surface of
the catheter, so as to maintain the position of the cuff
positioning device relative to the catheter. The sufficient surface
adherence between the inner wall of the cuff positioning device and
the catheter is due to an interference fit relationship.
[0035] In one embodiment of the present invention, an in-growth
cuff is mounted near the distal end of the cuff positioning device,
and suture wings are mounted to the proximal end of the cuff
positioning device. The cuff positioning device is mounted onto a
carrier system which is mounted onto the catheter. The inner
surface of the carrier system provides relatively low surface
adherence to the outer surface of the catheter so as to permit the
carrier system to be readily longitudinally moved along the
catheter shaft for precise positioning. The carrier system holds
the inner wall of the cuff positioning device in a first expanded
radial state.
[0036] In another embodiment of the invention, the carrier system
may be removed from the lumen of the cuff positioning device. The
inner wall of the cuff positioning device then contracts to a
second radial state. The carrier system may be removed from the
lumen of the cuff positioning device by manually pulling in
opposite directions abutting finger tabs that are intersected by at
least one longitudinal splittable line at a carrier system hub and
retracting the carrier system. Once the carrier system is removed,
the position of the cuff positioning device relative to the
catheter is maintained due to a sufficient surface adherence
between the inner wall of the cuff positioning device and the outer
surface of the catheter. The catheter tip and the in-growth cuff
that is mounted on the cuff positioning device are thereby
adjustable in relation to each other for precise positioning and
are subsequently permanently fixed in relation to each other at the
desired position relative to the patient's anatomy.
[0037] In another embodiment of the invention, a coiled spring may
be embedded inside the wall of the cuff positioning device to
provide an additional radially compressive force around the lumen
of the cuff positioning device. This design further enhances the
surface adherence between the inner wall of the cuff positioning
device and the catheter, so as to further ensure that the cuff
positioning device is retained in relation to the catheter.
[0038] In yet another embodiment of the invention, the cuff
positioning device also has a means to secure the cuff positioning
device to a patient's skin.
[0039] In another aspect of the invention, a method of retaining
the position of a catheter using a catheter retention assembly that
is pre-assembled on the catheter is disclosed. The method involves
inserting a catheter having a cuff positioning device with an
in-growth cuff and a lumen defined by an inner wall, and a carrier
system, into a skin incision site. The method further involves
positioning the distal end of the catheter at a desired location,
moving the catheter retention assembly to a desired location, and
removing the carrier system from the lumen of the cuff positioning
device, so as to simultaneously fix the position of the catheter
and the in-growth cuff on the cuff positioning device relative to
one another. The carrier system may be removed by pulling abutting
finger tabs in opposite directions away from the cuff positioning
device and retracting the carrier system. After the carrier system
is removed, the inner wall of the cuff positioning device contracts
to a second radial state, thereby locking the cuff positioning
device around the catheter. This permanently fixes the position of
the cuff positioning device and the catheter relative to one
another. The cuff positioning device is resilient, thereby allowing
it to expand and contract.
[0040] In another aspect of the invention, a method of exchanging a
catheter with a cuff positioning device for a new catheter is
presented. This method involves mounting an expander over a
catheter, advancing the expander between an inner wall of a cuff
positioning device lumen and the outer wall of the catheter,
expanding the lumen of the cuff positioning device, removing the
catheter from the cuff positioning device, placing a new catheter
through the expander, and removing the expander.
[0041] These and other embodiments, aspects, advantages, and
features of the present invention will be set forth in part in the
description which follows, and in part will become apparent to
those skilled in the art by reference to the following description
of the invention and referenced drawings or by practice of the
invention. The aspects, advantages, and features of the invention
are realized and attained by means of the instrumentalities,
procedures, and combinations particularly pointed out in the
appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0042] The accompanying drawings are included to provide an
understanding of the invention and constitute a part of the
specification.
[0043] FIG. 1 is a schematic illustration of the cuff positioning
device and catheter inserted into a patient with the distal tip of
the catheter in the right atrium and the cuff positioning device
inserted into the incision site.
[0044] FIG. 2A is an end view of the catheter retention
assembly.
[0045] FIG. 2B is a longitudinal plan view of an embodiment of the
device of this invention illustrating the catheter retention
assembly. The catheter retention assembly has a cuff positioning
device and a carrier system positioned through the cuff positioning
device lumen.
[0046] FIGS. 3A and 3B are, respectively, an end view and a side
elevation view of the cuff positioning device without the carrier
system in accordance with the present invention.
[0047] FIG. 4 is a plan view of the cuff positioning device
positioned on a catheter in accordance with the present
invention.
[0048] FIG. 5A is a partial view of the cuff positioning device
positioned on a catheter during insertion into a skin incision site
in accordance with the present invention.
[0049] FIG. 5B is a partial view similar to that of FIG. 5A, except
that the in-growth cuff has been partially positioned within the
skin incision site, and the carrier system finger tabs have been
separated to split the carrier system along a splittable line in
accordance with the present invention.
[0050] FIG. 5C is a partial view similar to that of FIG. 5B, after
the carrier system has been removed in accordance with the present
invention.
[0051] FIGS. 6A and 6B illustrate the use of a coiled spring to
provide additional compressing force in accordance with the present
invention.
[0052] FIG. 6A is a cross-sectional view of the coiled spring in
accordance with the present invention.
[0053] FIG. 6B is a cross-sectional end view of the cuff
positioning device with the coiled spring embedded within the cuff
positioning device wall in accordance with the present
invention.
[0054] FIG. 7A is a partial view of a catheter with an expander
sheath mounted around the catheter shaft, as it is being advanced
toward the lumen of the cuff positioning device to facilitate
catheter exchange.
[0055] FIG. 7B is a partial view of a catheter with the expander
sheath coaxially arranged around the catheter shaft as the catheter
and the expander sheath are inserted into and advanced through the
lumen of the cuff positioning device.
[0056] FIG. 7C is a partial view of a catheter with the expander
sheath as the catheter is partially removed from the lumen of the
cuff positioning device.
[0057] FIG. 7D is a partial view of the cuff positioning device and
expander sheath after the catheter has been removed.
DETAILED DESCRIPTION OF THE INVENTION
[0058] The following detailed description should be read with
reference to the drawings, in which fake elements in different
drawings are identically numbered. The drawings, which are not
necessarily to scale, depict selected preferred embodiments and are
not intended to limit the scope of the invention. The detailed
description illustrates by way of example, not by way of
limitation, the principles of the invention.
[0059] The present invention pertains to a catheter retention
assembly for use with a catheter and a method of inserting,
positioning, and retaining the position of a catheter inside the
body of a patient using the catheter retention assembly. The
catheter retention assembly is illustrated in FIGS. 1-6.
[0060] FIG. 1 illustrates a preferred positioning of a tunneled
venous access catheter 29. To obtain an optimal position, the
distal end 33 of the venous access catheter 29 is inserted into a
skin incision site 41 in a patient through a tunnel track into the
jugular vein at veinotomy 57. The distal end 33 of the venous
access catheter 29 is then advanced into the right atrium 55. The
catheter shaft 31 is shown as it is extended into the right atrium
55. The cuff positioning device 1 is shown partially inserted into
the tunnel track with the in-growth cuff 11 positioned at least 2
an deep into the tunnel track. Optimal positioning of the in-growth
cuff 11 allows the cuff positioning device 1 to be sutured to the
patient's skin using the suture wings 7 at a location that
minimizes patient discomfort and enhances fixation of the in-growth
cuff 11.
[0061] In one embodiment of the invention, the catheter retention
assembly 2 may be used to fix the position of a venous access
catheter 29. FIG. 2A and FIG. 2B illustrate the catheter retention
assembly 2 prior to deployment on a venous access catheter 29. As
shown in the longitudinal plan view of FIG. 2B, the catheter
retention assembly 2 has a carrier system 17 that may be removed
and a cuff positioning device 1. The carrier system 17 may have a
carrier system hub 19 and a carrier system shaft 21 with a through
lumen 23. The carrier system hub 19 has at least one carrier system
finger tab 28 to facilitate longitudinal splitting of the carrier
system 17. The cuff positioning device 1 is coaxially mounted on
the carrier system shaft 21. The cuff positioning device 1 includes
an in-growth cuff 11 that is mounted at or near the distal end 13
of the cuff positioning device 1, a cuff positioning body 3, and
suture wings 7 located near the proximal end 15 of the cuff
positioning device 1. Referencing FIG. 2A, the cuff positioning
device 1 also includes a longitudinal cuff positioning device lumen
defined by an inner wall 6, which extends from the distal end 13 of
the cuff positioning device 1 to the proximal end 15 of the cuff
positioning device 1, through which the carrier system shaft 21 is
placed.
[0062] In one embodiment, the carrier system 17 has at least one
splittable line 25 that facilitates manual longitudinal splitting
and removal of the carrier system 17. The splittable line 25 runs
longitudinally through the shaft 21 of the carrier system 17 and
extends through a carrier system hub 19 at the proximal end of the
carrier system 17. The splittable line 25 intersects abutting
finger tabs 28 at the carrier system hub 19. The carrier system
splittable line 25 may be pre-weakened or perforated in order to
further facilitate removal and splitting of the carrier system 17
into even sections on either side of the splittable line 25. The
distal end portion of the carrier shaft 21 may be tapered to
facilitate advancement through the tunnel track.
[0063] As assembled, the carrier system 17 and cuff positioning
device 1 is fixed in position relative to each other so as to
prevent independent movement of either of these components.
Fixation of the carrier system 17 and the cuff positioning device 1
are facilitated by an interference fit relationship between the
cuff positioning device 1 and the carrier system 17. The
interference fit relationship is due to the use of a combination of
selected materials and dimensions of the components of the catheter
retention assembly 2. Using a standard dialysis catheter carrier
system as an example, the outer diameter of the carrier system 17
may be approximately 0.227 inches. The cuff positioning device 1
may have a diameter at the inner wall 6 of approximately 0.200
inches before expansion of 0.027 inches. These combined dimensions
produce an interference fit relationship between the carrier system
17 and the cuff positioning device 1 when assembled, as shown in
FIG. 2A.
[0064] The carrier system shaft 21 is preferably composed of a
material such as polytetrafluoroethylene (PTFE). This material
provides the carrier system shaft 21 with the necessary radial
strength to prevent compression or collapse of the carrier system
lumen 23 when the lumen 23 is compressed by the cuff positioning
device 1, due to the interference fit relationship between the cuff
positioning device 1 and the carrier system 17.
[0065] The cuff positioning device 1 is resilient and may be
composed of an elastomeric material of a softer durometer and
higher elastic limit than the carrier system shaft 21. The
elastomeric material of the cuff positioning device 1 may be any
suitable material. Preferably, the elastomeric material is any
urethane-based material of a low durometer and high elastic limit.
This permits the cuff positioning device lumen 5 (ref. FIG. 3A) to
expand radially outward during assembly to accommodate the outer
diameter of the shaft 21 of the carrier system 17. The high elastic
limit of the material also ensures that the inner wall 6 of the
cuff positioning device will return to its original unexpanded
diameter after the carrier system 17 is removed.
[0066] Elastic limit is defined as the point at which a material no
longer undergoes a change in strain linearly proportional to the
change in stress. At stress levels below the elastic limit the
material is elastic. Once the material exceeds this limit, it is
undergoes plastic deformation, also known as permanent deformation.
At this point the material will no longer return to its original
size. The elastic limit of the elastomer used in the cuff
positioning device 1 is sufficiently high to allow it to expand
without undergoing plastic deformation, thereby returning to its
original state after force is removed.
[0067] Although the carrier system 17 may have a longitudinally
splittable configuration, other carrier systems are within the
scope of this invention. For example, two independent
semi-cylindrical tubular structures may be held in place within the
cuff positioning device lumen 5 by the compressive force of the
inner wall 6 of the cuff positioning device 1. An example of this
embodiment is illustrated in FIG. 7B, as element 49. Tubular
materials may include PTFE, stainless steel, or other semi-rigid or
rigid materials. A single semi-cylindrical tubular structure is
also contemplated. In one such embodiment, the cylindrical tubular
body has a single longitudinal slit extending the length of the
tubular body. The slit is in a normally dosed position, but may be
expanded to an open position sufficient to allow removal from the
cuff positioning device lumen 5 and catheter shaft 31.
[0068] The carrier system 17 may be any removable or non-removable
carrier mechanism that is suitable for holding the inner wall 6 of
the cuff positioning device 1 in a radially expanded state while
the cuff positioning device 1 is advanced over the venous access
catheter 29 and into the tunnel track of a patient. In the
non-removable carrier design, the carrier system is retracted or
activated, allowing the inner wall 6 of the cuff positioning device
1 to return to its second radially contracted state and to become
fixed to the catheter shaft 31. A locking clamp or spring, such as
a C-shaped clamp or spring or a helical clamp embedded in or
attached directly to the cuff positioning device 1 may act as the
carrier system 17. The carrier system 17 is activated to switch the
cuff positioning device 1 from the first expanded radial state to a
second contracted fixed position. Accordingly, the carrier system
17 may be, but is not limited to, a peel-away or non peel-away
sleeve, a tube or cannula, or an internal mechanism within the body
of the cuff positioning device 1.
[0069] Referring now to FIGS. 3A and 3B, the cuff positioning
device 1 is illustrated as it is disassembled from the carrier
system 17. FIG. 3A is an end view of the cuff positioning device 1
with the in-growth cuff 11. FIG. 3B illustrates a side elevation
view of the cuff positioning device 1 of the invention with an
in-growth cuff 11 near the distal end 13 of the cuff positioning
device 1. The cuff positioning device 1 is preferably approximately
1.5 inches in length, but may also be of varying lengths to
accommodate venous access catheters of different sizes and types.
The cuff positioning device 1 has a cuff positioning body 3 and a
cuff positioning device lumen 5 defined by an inner wall 6. The
cuff positioning device 1 is tapered from a first diameter at the
proximal end 15 of the cuff positioning device 1 to a second
smaller diameter at the distal end 13 of the cuff positioning
device 1. The tapered design of the cuff positioning device 1
facilitates insertion and advancement of the venous access catheter
29 into the tunnel track during catheter placement. The tapered
profile of the cuff positioning device 1 also minimizes inward
migration of the cuff positioning device 1 within the tunnel track
prior to tissue incorporation of the in-growth cuff 11. The tapered
profile of the cuff positioning body 3 also provides a temporary
tunnel sealing function by virtue of the expanded proximal outer
diameter of the cuff positioning device 1.
[0070] The cuff positioning body 3 has an in-growth cuff 11 that is
circumferentially mounted near the distal end 13 of the cuff
positioning device 1. The in-growth cuff 11 promotes tissue
in-growth, thereby permanently fixing the venous access catheter 29
in place and creating a barrier to the entrance of bacteria into
the tunnel track from the skin surface. The in-growth cuff 11 may
be approximately 0.16 inches in length. However, any length
sufficient to promote tissue in-growth within the tunnel is within
the scope of this invention. The in-growth cuff 11 may be made of
any suitable porous or fibrous material. Preferably, the material
is a polyester material, such as Dacron.RTM.. The in-growth cuff 11
may be embedded with medicinal agents that enhance tissue in-growth
or minimize infection.
[0071] The cuff positioning body 3 also has a means to secure the
cuff positioning device 1 to a patients skin. Such means may be a
pair of suture wings 7 disposed on the proximal end 15 of the cuff
positioning device 1. The suture wings 7 may have a width of
approximately 0.83 inches between the outer tips of the suture
wings 7. The suture wings 7 have suture wing holes 9 located in the
center of each suture wing 7. Each of the suture wing holes 9 may
have a diameter that is approximately 0.090 inches. The suture
wings 7 may be formed as part of the cuff positioning device 1 by
using injection molding, or alternatively may be separately molded
over the cuff positioning device 1. The suture wings 7 may be made
of any suitable material. Preferably, the suture wings 7 are made
of any urethane-based elastomeric material.
[0072] In another embodiment of the invention, illustrated in FIG.
4, the catheter retention assembly 2 is illustrated mounted on the
catheter shaft 31. Although a chronic dialysis catheter is shown in
FIG. 4, the embodiment is applicable to all types and sizes of
venous access catheters. The dialysis catheter has extension tubes
37 for connection to a dialysis machine, extension tube clamps 45,
a bifurcated catheter hub 35, catheter hub connectors 39, and a
catheter shaft 31 which extends to the distal end 33 of the venous
access catheter 29.
[0073] The catheter retention assembly 2 may be pre-mounted on the
catheter shaft 31 or may be placed on the venous access catheter 29
by the physician just prior to the catheter insertion procedure. To
assemble the catheter retention assembly 2 onto the venous access
catheter 29, the distal end of the catheter 33 is inserted through
the carrier system hub 19 and advanced through the carrier system
lumen 23 until the carrier system hub 19 is in a position near the
catheter hub 35, as shown in FIG. 4.
[0074] The dimensions of the outer diameter of the catheter shaft
31 and the inner diameter of the carrier system shaft 21 allow the
catheter retention assembly 2 to slidably and longitudinally move
along the catheter shaft 31. The inner diameter of the carrier
system shaft 21 may be approximately 0.207 inches to provide a
close fit between the distal ends of both components to facilitate
insertion but still allow sufficient luminal area to freely
accommodate the outer diameter of the venous access catheter 29,
which may be approximately 0.205 inches. Longitudinal movement of
the catheter retention assembly 2 is also facilitated by the
material of the carrier system shaft 21. Polytetrafluoroethylene
(PTFE) materials, for example Teflon.RTM., provide sufficient
radial strength, stiffness, and a low enough co-efficient of
friction to ensure that the catheter retention assembly 2 will
slide smoothly and freely over the catheter shaft 31.
[0075] As illustrated in FIGS. 5A-5C, a method of optimally
positioning and retaining the tip of a venous access catheter 29
relative to the in-growth cuff 11 at a desired location in a
patient's body is provided. Typically, the tip of the venous access
catheter 29 is placed in the right atrium 55 (ref. FIG. 1). The
venous access catheter 29 may be optimally positioned and retained
inside a patient's body by providing a catheter retention assembly
2. The catheter retention assembly 2 includes a cuff positioning
device 1 with an in-growth cuff 11 mounted near the distal end 13
of the cuff positioning device 1. The venous access catheter 29
assembled with the catheter retention assembly 2 is placed in the
patient's body by first inserting the venous access catheter 29
into a tunneled skin incision site 41 of a patient, positioning the
distal end 33 (not shown) of the venous access catheter 29 at at a
desired location within the central venous system, moving the
catheter retention assembly 2 to a desired location along the
catheter shaft 31 by longitudinally sliding the catheter retention
assembly 2 over the catheter shaft 31, and removing the carrier
system 17 from the catheter retention assembly 2, so as to
permanently fix the position of the cuff positioning device 1 and
the catheter 29 relative to one another.
[0076] In FIG. 5A, after a skin incision site 41 is created in a
patient's skin, the distal section of the catheter shaft 31 is
inserted into the patient's vascular system (not shown) through a
subcutaneous tunnel created below the patient's skin, as previously
described. The remaining, or extracorporeal portion of the venous
access catheter 29 is positioned outside of the skin incision site
41. The extracorporeal portion of the venous access catheter 29
includes a catheter retention assembly 2 in a longitudinally
slidable arrangement with the catheter shaft 31. The catheter
retention assembly 2 has a cuff positioning device 1 with a cuff
positioning body 3 and an in-growth cuff 11 that is
circumferentially located near the distal end 13 of the cuff
positioning device 1. The cuff positioning device 1 also includes
suture wings 7 that are disposed on each side of the cuff
positioning body 3 at the proximal end 15 of the cuff positioning
body 3.
[0077] In the pre-deployed state of the catheter retention assembly
2, the carrier system shaft 21 extends distally from the distal end
13 of the cuff positioning device 1 through the cuff positioning
body 3 to the carrier system hub 19. At least two abutting carrier
system finger tabs 28 are intersected by at least one longitudinal
carrier system splittable line 25 along the longitudinal axis of
the carrier system shaft 21 near the proximal end of the venous
access catheter 29.
[0078] In FIG. 5B, the tip of the venous access catheter 29 (not
shown) has been positioned at a desired location of therapeutic
activity inside the patient's body. The cuff positioning body 3
with the in-growth cuff 11 mounted near the distal end 13 of the
cuff positioning device 1 may be readily longitudinally advanced
toward the distal end of the catheter shaft 31 and into the tunnel
track through the skin incision site 41. The cuff positioning body
3 may be readily longitudinally moved in relation to the venous
access catheter 29 due to a relatively low adherence between the
carrier system lumen 23 and the outer surface of the venous access
catheter 29.
[0079] The catheter retention assembly 2 is moved to a desired
location by advancing the catheter retention assembly 2 relative to
the skin incision site 41 while holding the venous access catheter
29 stationary. Once the physician has placed the catheter retention
assembly 2 in the desired position, the carrier system 17 is
removed from the cuff positioning device lumen 5. Removal of the
carrier system 17 is facilitated by manually gripping and pulling
the carrier system finger tabs 28 away from the catheter shaft 31
in opposite directions along the carrier system splittable line 25
and retracting the carrier system 17. The carrier system 17 is thus
concurrently separated into two evenly proportioned sections for
removal.
[0080] FIG. 5C illustrates the cuff positioning device 1 after the
carrier system 17 has been completely removed from the venous
access catheter 29. The cuff positioning device 1 is optimally
positioned with the tapered distal portion of the cuff positioning
body 3 and the in-growth cuff 11 inserted into the tunnel track.
The distal portion of the cuff positioning body 3 remains adjacent
to the skin incision site 41 outside of the tunnel track. The
extracorporeal portion of the cuff positioning device 1 includes
suture wings 7, which are used for suturing to the patient's skin
surface in a location which minimizes patient discomfort.
[0081] When the carrier system 17 is removed, the cuff positioning
body 3 circumferentially locks down around the catheter shaft 31.
Specifically, the removal of the carrier system shaft 21 from the
cuff positioning body 3 causes the inner wall 6 of the cuff
positioning device 1 to contract from a first radially expanded
state to a second radial state that is smaller than the first
radially expanded state. The elastomeric material of the cuff
positioning device 1, which has a high elastic limit, imparts
sufficient elastic recoil characteristics to allow the inner wall 6
of the cuff positioning device 1 to expand and contract without
plastic deformation. As an example, the cuff positioning device
lumen 5 is held at a first state where the diameter of the inner
wall 6 of the cuff positioning device 1 is equal to or greater than
the carrier system shaft 21 outer diameter of approximately 0.227
inches, while the carrier system 17 is in place within the cuff
positioning device lumen 5. Once the carrier system 17 is removed,
the cuff positioning device inner wall 6 will return to its
original diameter of approximately 0.200 inches. Thus, the cuff
positioning device 1 is resilient allowing the inner wall 6 to
return from a first expanded state, maintained by the radially
outward force of the carrier system 17, to a second, contracted
state in the absence of the radially outward-expanding force.
[0082] The second, contracted state of the inner wall 6 of the cuff
positioning device 1 creates sufficient surface adherence between
the cuff positioning device 1 and the catheter shaft 31, so as to
permanently fix the cuff positioning device 1 at the desired
location on the catheter shaft 31. Sufficient surface adherence is
due to choosing a combination of materials with an appropriate
co-efficient of friction, compression interference, or polymer
cross-linking properties, such that the cuff positioning device 1
and the catheter shaft 31 are fixed in relation to one another.
Once the carrier system 17 is removed, the cuff positioning device
1 cannot be moved from its longitudinal position on the catheter
shaft 31. Thus, the surface adherence created between the inner
wall 6 of the cuff positioning device 1 and the catheter shaft 31
allows for long term placement and retention of the cuff
positioning device 1 and the venous access catheter 29 in relation
to each other. This long term retention may be enhanced by
additional friction or long term molecular migration between the
cuff positioning device 1 and the catheter shaft 31. In addition,
the surface adherence fit between the cuff positioning device inner
wall 6 and the outer surface of the venous access catheter 29 is
advantageous because it does not substantially compromise the
luminal area of the catheter shaft 31.
[0083] Once the cuff positioning device 1 is positioned within the
skin incision site 41 as desired, and the carrier system 17 is
removed, the venous access catheter 29 may then be sutured in the
preferred location on the patient's skin just adjacent to the skin
incision site 41 using the suture wings 7. The suture wings 7 of
the cuff positioning device 1 are optimally located in order to
minimize patient discomfort, while simultaneously ensuring that the
implanted catheter position remains fixed during the time period
required for the in-growth cuff 11 to completely be incorporated
into the subcutaneous tissue.
[0084] In another embodiment of the invention, as illustrated in
FIGS. 6A and 6B, the invention further encompasses applying an
additional radial compressive force to the inner wall 6 of the cuff
positioning device 1 to enhance the radial contraction of the cuff
positioning device lumen 5 after positioning the venous access
catheter 29. The additional radial compressive force enhances the
sufficient surface adherence between the inner wall 6 of the cuff
positioning device 1 and the venous access catheter 29. The radial
compressive force is applied by deploying a spring 43 that is
embedded inside of the wall of the cuff positioning body 3. The
spring 43 is illustrated in FIG. 6A. The spring 43 is designed to
provide an enhanced compression force around the catheter shaft 31
after the carrier system 17 is removed. In effect, the spring 43
snaps the cuff positioning device 1 into place onto the venous
access catheter 29.
[0085] As illustrated in FIG. 68, the spring 43 is embedded inside
the wall of the cuff positioning device 1 to provide additional
compressive force. The spring 43 may embedded inside of the cuff
positioning body 3 using standard molding techniques. Mother method
involves forming a circumferential groove in the cuff positioning
device 1. The spring 43 is placed within the groove, and a
secondary polymer layer is then added to the cuff positioning
device 1 to fully encapsulate the spring 43. The spring 43
surrounds the cuff positioning device lumen 5. The spring 43 may be
configured as a helical coil, C-clamp or other configuration. The
spring 43 may be composed of any material that has shape memory
characteristics. Preferably, the spring 43 may be made of any
material including, but not limited to, stainless steel and
nitinol. Most preferably, the spring 43 is composed of nitinol. The
nitinol may be approximately 0.0085 inches in thickness. The
internal diameter of the nitinol spring may be approximately 0.196
inches.
[0086] In yet another embodiment of the invention, as illustrated
in FIGS. 7A through 7D, the cuff positioning device 1 allows a
physician to exchange the venous access catheter 29 for a new
catheter. Catheter exchanges are often done to address
complications such as infection, catheter occlusion, or catheter
mis-positioning. Catheter exchanges typically require creation of a
new tunnel track through the subcutaneous tissue. A new cuff is
placed as part of the exchange procedure. As result, temporary
retention mechanisms must be used to fix the replacement catheter
in place until in-growth of tissue into the new cuff has occurred,
typically taking several weeks.
[0087] In the method of this invention, the same tunnel track may
be used for the catheter exchange, thereby eliminating a
time-consuming procedural step, as well as the discomfort and
complications associated with creating a new tunnel track. The
method of this invention is also advantageous in that the cuff
positioning device 1 is not removed, thereby eliminating the need
for temporary suturing or retention required if a new cuff was
placed.
[0088] The method of exchanging the venous access catheter 29
involves coaxially mounting an expander 47 over the catheter shaft
33 and advancing it toward the distal end of the catheter 33. The
expander 47 has an expander sheath 49 that may be tapered at the
distal end 51 in order to facilitate entry of the distal end of the
expander 51 between the cuff positioning device 1 and the catheter
shaft 31. The expander sheath 49 may be a hollow tube that is made
of any suitable material that is rigid and is capable of acting as
a lumen expander. The expander sheath 49 may be comprised of one or
more semi-cylindrical tubular structures. Preferably, the expander
is a cannula made of stainless steel. FIG. 7A illustrates an
expander sheath 49 after it has been mounted over the catheter
shaft 31 of an indwelling catheter with a cuff positioning device
1.
[0089] The expander sheath 49 is then advanced between the inner
wall 6 of the cuff positioning device lumen 5 and the outer wall of
the venous access catheter 29, as illustrated in FIG. 7B, thereby
expanding the lumen 5 of the cuff positioning device 1, removing
the venous access catheter 29 from the cuff positioning device 1,
placing a new catheter through the expander, and removing the
expander. The expander sheath 49 is advanced between the inner wall
6 of the cuff positioning device lumen 5 and the outer wall of the
venous access catheter 29 until the tapered distal end 51 of the
expander 47 extends distally of the in-grown cuff 11. The radially
expanding force of the expander sheath 49 causes the inner wall 6
of the cuff positioning device 1 to move from a first radially
contracted state to a second radially expanded state. The elastic
characteristics of the cuff positioning device 1 facilitate the
lumen expansion.
[0090] The venous access catheter 29 is then removed from the
patient's body through the cuff positioning device lumen 5, as
illustrated in FIG. 7C, by longitudinally retracting the catheter
shaft 31 through the cuff positioning device lumen 5 in the
direction indicated by the arrow. The catheter shaft 31 moves
freely through the cuff positioning device lumen 5 because the
radially outward force of the expander sheath 49 against the inner
wall 6 of the cuff positioning device 1 creates an expanded
cross-luminal area larger than the catheter shaft 31 outer
diameter. The cuff positioning device 1 remains in a fixed position
during the catheter removal due to retention by the in-growth cuff
11.
[0091] FIG. 7D illustrates the cuff positioning device 1 with the
expander sheath 49 after the catheter has been completely removed
from the patient. To place a new exchange catheter (not shown)
within the same tunnel track, the physician inserts the distal tip
of the new catheter into the lumen of the expander sheath 49 and
advances it through the tunnel track. Advancement may be
facilitated by using medical accessory devices well known in the
art such as guidewires, tunnelers, dilators, and others. The new
catheter advances freely through the cuff positioning device 1 due
to the temporarily expanded lumen created by the expander sheath
49. After the catheter tip has been positioned in the desired
location, the physician removes the expander sheath 49 from the
cuff positioning device 1. Removal of the expander sheath 49 causes
the inner wall 6 of the cuff positioning device 1 to move from its
expanded state to a contracted state, thus creating an interference
fit between the outer surface of the catheter shaft 31 and the
inner wall 6 of the cuff positioning device 1. The interference fit
ensures that the new catheter remains fixed in the desired state in
relation to the cuff positioning device.
[0092] The catheter retention assembly 2 of the instant invention
reduces the risk of infection and thereby enhances the
antimicrobial properties of the venous access catheter 29 by
providing for the optimal, secure positioning and retention of the
venous access catheter 29 tip and the in-growth cuff 11 of the cuff
positioning device 1 relative to each other inside a patient's
body. The catheter retention assembly 2 also eliminates the
time-consuming step of trimming or adjusting the venous access
catheter 29 and decreases the chance of error in achieving the
proper length of the venous access catheter 29.
[0093] This ability to simultaneously position the tip of the
venous access catheter 29 and the in-growth cuff 11 on the cuff
positioning device 1 allows the position of the venous access
catheter 29 tip and the in-growth cuff 11 to be optimally placed
and retained relative to each other and also allows for a tight,
secure connection between the cuff positioning device 1 and the
venous access catheter 29 so as to prevent fluid from leaking out
of the venous access catheter 29 or the skin incision site 41.
[0094] The catheter retention assembly 2 and methods of insertion
and removal also eliminate the problems associated with tunneling
catheters too deeply because the catheter retention assembly 2
facilitates placement of the in-growth cuff 11 in an optimal
position within a tunneling track. Placing the in-growth cuff 11
too deeply in the tunnel track may result in poor tissue
incorporation into the in-growth cuff 11. Incomplete in-growth has
been known to cause peri-catheter leakage, increased infection
rates, and difficulty in removing the catheter. The catheter
retention assembly 2 of the present invention also does not
compromise or weaken the integrity of the venous access catheter
29. The catheter retention assembly 2 of the present invention also
allows the venous access catheter 29 to be exchanged with a new
catheter.
[0095] The foregoing proposed catheter could be applied to all
types of venous access catheters, including, but not limited to,
hemodialysis catheters, peritoneal catheters, PICC lines, central
venous catheters, or tunneled venous access catheters. Most
preferably, the cuff positioning device 1 is used with a tunneled
venous access catheter. The preferred embodiment is exemplary of
catheter positioning assemblies for use with catheters generally,
and the detailed dimensions are given for example only. Such other
structures are within the scope of the invention as claimed.
[0096] The above disclosure is intended to be illustrative and not
exhaustive. This description will suggest many variations and
alternatives to one of ordinary skill in this art. All these
alternatives and variations are intended to be included within the
scope of the claims where the term "comprising" means "including,
but not limited to". Those familiar with the art may recognize
other equivalents to the specific embodiments described herein,
which equivalents are also intended to be encompassed by the
claims.
[0097] Further, the particular features presented in the dependent
claims can be combined with each other in other manners within the
scope of the invention such that the invention should be recognized
as also specifically directed to other embodiments having any other
possible combination of the features of the dependent claims. For
instance, for purposes of claim publication, any dependent claim
which follows should be taken as alternatively written in a
multiple dependent form from all prior claims which possess all
antecedents referenced in such dependent claim if such multiple
dependent format is an accepted format within the jurisdiction
(e.g., each claim depending directly from claim 1 should be
alternatively taken as depending from all previous claims). In
jurisdictions where multiple dependent claim formats are
restricted, the following dependent claims should each be also
taken as alternatively written in each singly dependent claim
format which creates a dependency from a prior
antecedent-possessing claim other than the specific claim listed in
such dependent claim below.
[0098] This completes the description of the preferred and
alternate embodiments of the invention. Those skilled in the art
may recognize other equivalents to the specific embodiment
described herein which equivalents are intended to be encompassed
by the claims attached hereto.
* * * * *