U.S. patent application number 13/652990 was filed with the patent office on 2013-02-14 for self-cleansing bladder drainage catheter.
This patent application is currently assigned to XENNOVATE MEDICAL, LLC. The applicant listed for this patent is David Smith. Invention is credited to David Smith.
Application Number | 20130041352 13/652990 |
Document ID | / |
Family ID | 39367535 |
Filed Date | 2013-02-14 |
United States Patent
Application |
20130041352 |
Kind Code |
A1 |
Smith; David |
February 14, 2013 |
Self-Cleansing Bladder Drainage Catheter
Abstract
An indwelling endourethral drainage catheter includes a tubular
distal portion and a spiral first portion. A central lumen extends
along substantially the entire length of the catheter. The spiral
first portion defines an outer spiral channel in fluid
communication with the central lumen. The distal end of the
catheter is anchored externally so that the catheter is held
against advancement into or out of the urethra. In certain methods,
the diameter of the spiral first portion may be changed to address
obstructions within the urethra or facilitate navigation of the
catheter along the urethra.
Inventors: |
Smith; David; (Richmond,
IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Smith; David |
Richmond |
IN |
US |
|
|
Assignee: |
XENNOVATE MEDICAL, LLC
Richmond
IN
|
Family ID: |
39367535 |
Appl. No.: |
13/652990 |
Filed: |
October 16, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11553780 |
Oct 27, 2006 |
8287519 |
|
|
13652990 |
|
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Current U.S.
Class: |
604/544 |
Current CPC
Class: |
A61M 25/04 20130101;
A61M 25/10 20130101; A61M 2025/0019 20130101; A61M 25/0017
20130101 |
Class at
Publication: |
604/544 |
International
Class: |
A61M 27/00 20060101
A61M027/00 |
Claims
1. A method for advancing an indwelling endourethral drainage
catheter along the urethra of a patient into the bladder
comprising: providing a drainage catheter having at least a spiral
first portion and a second portion; rotating the first portion
relative to said second portion so that the diameter of the first
portion changes; and then advancing the drainage catheter along the
urethra.
2. The method for advancing an indwelling endourethral drainage
catheter of claim 1, wherein said rotating step includes rotating
the second portion in a first direction to decrease the diameter of
the first portion to facilitate passage of the first portion
through the urethra.
3. The method for advancing an indwelling endourethral drainage
catheter of claim 1, wherein said rotating step includes rotating
the second portion in a second direction to increase the diameter
of the first portion to bear against an obstruction within the
urethra.
4. The method for advancing an indwelling endourethral drainage
catheter of claim 3, further comprising capturing the obstruction
within the drainage catheter.
5. The method for advancing an indwelling endourethral drainage
catheter of claim 4, further comprising rotating the second portion
in a first direction opposite the second direction to decrease the
diameter of the first portion to facilitate passage of the first
portion through the urethra.
6. The method or advancing an indwelling endourethral drainage
catheter of claim 1, wherein: the first portion includes a tip
configured to be disposed within the bladder when the drainage
catheter is fully inserted through the urethra; and the rotating
step includes advancing a stylet through the drainage catheter into
contact with the tip to hold the tip against rotation.
7. A method for advancing an indwelling endourethral drainage
catheter along the urethra of a patient into the bladder
comprising: providing a drainage catheter having a spiral first
portion and a tubular second portion, the catheter defining a
central lumen therethrough and the first portion defining an outer
channel in fluid communication with the central lumen; advancing
the drainage catheter into the urethra until an obstruction is
encountered; rotating said second portion to engage the obstruction
within the outer channel.
8. The method for advancing an indwelling endourethral drainage
catheter along the urethra of a patient into the bladder of claim
7, wherein said rotating step includes rotating the first portion
in a direction that advances the obstruction along the outer
channel into the central lumen.
9. A method for advancing an indwelling endourethral drainage
catheter along the urethra of a patient into the bladder of claim
7, further comprising; advancing the catheter toward the bladder
until the first end of the first portion is within the bladder; and
rotating the first portion in a direction that advances the
obstruction along the outer channel into the bladder.
10. An indwelling endourethral drainage catheter comprising: a
tubular portion having an end adapted to be situated outside the
patient when the drainage catheter is indwelling, said tubular
portion defining a distal lumen extending along the length thereof;
a spiral portion attached to said tubular portion, said spiral
portion defining a proximal lumen in communication with said distal
lumen and further defining a helical outer channel along the length
of said spiral portion, said outer channel in fluid communication
with said proximal lumen, said spiral portion configured to open
and close said outer channel by rotation of said spiral portion;
and a blunt tip at an end of said spiral portion opposite said
tubular portion, said tip adapted for insertion through the urethra
of a patient, wherein said drainage catheter has a length from said
end of said tubular portion to said blunt tip that is sufficient to
span the length of the urethra with the helical outer channel in
communication with the bladder.
11. The indwelling endourethral drainage catheter of claim 10,
wherein said end of said tubular portion includes a fluid
fitting.
12. The indwelling endourethral drainage catheter of claim 10,
further comprising an anchor assembly for anchoring the catheter
within the urethra, said anchor assembly engaged to said tubular
portion and adapted to be disposed externally of the bladder and
urethra.
13. The indwelling endourethral drainage catheter of claim 10,
further comprising a stylet configured to pass through the proximal
and distal lumens and contact the blunt tip.
14. The indwelling endourethral drainage catheter of claim 10,
wherein said length is sufficient to span the length of the urethra
when said outer channel is closed.
Description
BACKGROUND
[0001] The present invention relates to a catheter for disposition
within the urinary tract of a patient. More particularly, the
invention concerns an indwelling drainage catheter.
[0002] The urinary tract of a patient includes the kidneys,
ureters, bladder, urethra and, in men, the prostate which encircles
the urethra adjacent the bladder. The bladder consists of the body,
the trigone and the bladder neck. In the male, the urethra is
typically divided into three sections--the prostatic, extending
along about the upper 4 cm of the urethra; the membranous section,
which narrows from the prostatic for about 1 cm; and the cavernous
which continues to the glans for about 15 cm. The lumen of the
urethra has a number of deep, irregular outpocketings, a multitude
of glands, and a rich network of capillaries.
[0003] Problems in the urinary tract can have serious consequences,
particularly when the problem is one of retention or incomplete
emptying. Retention problems can result from any of a number of
causes, including without limitation, spinal cord injury, typhoid,
peritonitis, prostatic enlargement, urethral stricture, urethritis,
cystitis, bladder tumors, or urethral calculus. Patients suffering
from these and other conditions often require some interventional
means to periodically drain or augment drainage of the bladder.
Further, the clinician often requires indwelling urinary drainage
to monitor urine production more closely, especially
post-operatively. Failure to do so can result in damage of the
epithelium and detrusor muscles associated with the bladder, and an
increased potential for bacterial invasion which is commonly
thought to contribute to urinary tract infection potentially
leading to life-threatening urosepsis or kidney failure.
[0004] These urinary tract problems may manifest themselves with a
variety of symptoms, such as: (i) incomplete emptying, (i.e., the
patient is only able to urinate small volumes, e.g. <100
milliliters (ml), or has an elevated volume of urine left in the
bladder following urination, e.g. >100 ml per attempt); (ii)
experiencing frequent urges to urinate; (iii) intermittency (e.g. a
patient's flow stops and starts often during urination); (iv)
having a very weak and inconsistent urine flow stream; and (v)
stress incontinence (e.g. leaking during lifting or straining as a
result of excessive urine in the bladder or weakened
sphincters).
[0005] Up to two million office visits annually in the United
States are attributed to patients being bothered by some form of
lower urinary tract symptoms (LUTS). For men, the symptoms are
typically suspected to be caused by the intrusion of an enlarged
prostate gland upon the urethra. Bladder outlet obstructions (BOO)
are a major subgroup of LUTS. It is estimated that nearly 75% of
men between the ages of 55 and 75 years have some degree of bladder
outlet obstruction. Bladder outlet obstructions are primarily
caused by the enlargement of the prostate gland (e.g., benign
prostate hyperplasia (BHP)) which results in radial compression of
the urethra surrounded thereby (i.e., the prostatic urethra), thus
obstructing (i.e., constricting) urine flow, resulting in
incomplete emptying of the bladder (i.e., there being what is
clinically referred to as a "post void residual" (PVR) remaining in
the bladder).
[0006] Devices have been developed to be positioned in the urethra
and/or bladder to correct the problems of obstruction and
incontinence of urine flow. Heretofore known problems associated
with endourethral devices, more particularly critical device
components such as stents, valve actuators, flow conduits, etc.,
generally relate to the physiology of the lower urinary tract
(e.g., ingrowth, instability, pitting, depositions, etc.). Problems
of device leakage or less than complete emptying of the bladder are
widely encountered. Furthermore, issues surrounding device
deployment and fit, positioning, repositioning, and retention
(i.e., sufficient anchoring) have been well documented. Catheter
associated urinary tract infections (CAUTI's) are frequently the
result of legacy indwelling drainage devices and it is thought that
up to 100,000 deaths/year can be attributed these devices.
[0007] It is especially critical that the endourethral device be
stable with respect to position (i.e., deployed in a
physiologically properly and stable position), and comfortable to
wear, as the urinary tract is sensitive to contact and friction.
Inter-urethral stents have been utilized within the prostatic
region, although many users foregoing such devices for alternate
therapies due to feelings of discomfort and/or pain. Many
endourethral devices have similarly been evaluated for urinary
incontinence for females. Based upon clinical findings, many have
been shown to be uncomfortable, thus severely retarding their
utility as a therapy. Other devices have migrated into the bladder,
or have been expelled under straining conditions.
[0008] One common drainage catheter is the Foley catheter and
variations thereof. The traditional Foley catheter includes an
inflatable balloon at the distal end of a catheter tube, as
depicted in FIG. 1. The balloon is deflated as the tube is advanced
up the urethra toward the bladder. Once the balloon traverses the
bladder sphincter, the balloon is inflated to prevent only
anterograde movement of the catheter within the urethra. The
proximal end incorporates a drainage inlet port in communication
with the catheter lumen for draining urine from the bladder. The
distal end also includes an inflation lumen that is adapted to
engage a source of saline for inflating the balloon in situ. The
distal end protrudes beyond the urethral orifice and can be
attached to a receptacle for collection of the nearly constantly
dripping urine. Optionally, a plug or valve may be incorporated at
the distal end to stop the flow of urine. While the traditional
Foley catheter uses a balloon for retention, variations have
incorporated alternative elements that are expandable and
contractible within the bladder. These variations all require an
additional lumen for passage of a control component for controlling
the expansion or contraction of the alternative element within the
bladder.
[0009] One problem associated with the Foley-type catheter is that
the retention balloon or element rests against the dome of the
bladder an area thought to be only three cells thick. Placement of
a retention device in this region often leads to pooling of urine,
or dead space, and may be partially responsible for the multitude
of infections caused by this device. This aspect can also cause
tissue compression and irritation of the sensitive tissue lining
the bladder, sometimes leading to erosion of the tissue. The
pressure of the retention element may also aggravate the
micturition reflex, or the electrical signal to urinate. The
bladder contracts in response to this signal, which leads to
further pressure and irritation at the area of contact between the
bladder and the retention element. These bladder contractions can
further result in oscillation of the catheter proximally and
distally since there is no anchoring the catheter to prevent
movement in the proximal direction. In some cases, inadequate
deflation or retraction of the retention element can occur, leading
to extreme discomfort and even damage to the urethra upon
withdrawal. The presence of the additional lumen for introduction
of inflation fluid or other actuation feature for the catheter
dramatically reduces the flow area of the drainage lumen.
[0010] Another problem associated with the Foley-type drainage
catheter is that the balloon or other retention element only
prevents retrograde movement, or movement distally toward the
urethral orifice. The retention element does not prevent movement
of the retention element and catheter deeper into the bladder.
Obviously, excessive distal movement of the catheter may cause
physical damage to the bladder. Irritation or abrading of the
mucosa within the urethra may also result by the continuous sliding
back and forth of the catheter within the urethra.
[0011] However, a more insidious result of this distal movement is
the increased instance of urinary tract infections. It has been
suggested that the increase in infection rate for long indwelling
catheter patients is due to migration of bacteria up the urethra,
coined "biofilm creep." In particular, it is believed that bacteria
infecting the distal end of the drainage catheter can be carried
into the urethra by each proximal movement of the catheter. As the
bacteria are advanced upward by this proximal movement, they adhere
to the tissue of the urethra. Some of the bacteria hold their
position as the catheter resets distally, only to hitch a ride
again when the catheter again moves proximally toward the bladder.
It has been suggested that this biofilm creep mechanism allows
bacteria to travel from the urethral orifice to the bladder in a
matter of minutes. Urine that would otherwise help "flush" the
urethra is isolated from the urethra as it passes through the
drainage lumen of the Foley catheter.
[0012] It is expected that an increasing number of long-term
drainage catheterizations will occur, especially as patients live
longer. Conventional drainage catheters are not designed for
prevent expensive and life threatening infections. There is a
significant need for a urinary drainage catheter that avoids these
problems associated with the Foley-type catheter.
SUMMARY OF THE INVENTION
[0013] In order to address this need for an improved indwelling
endourethral drainage catheter the present invention contemplates a
drainage catheter comprising a tubular distal portion having a
distal end adapted to be situated outside the patient when the
drainage catheter is indwelling and a spiral proximal portion
attached to said distal portion. A central lumen extends through
the proximal and distal portions for drainage of urine
therethrough. In accordance with one feature of the invention, the
proximal portion defines a helical outer channel along the length
thereof with the outer channel in fluid communication with the
central lumen. In a specific embodiment, the proximal and distal
portions are integrally formed and the proximal portion is provided
with a tip configured for smooth insertion into the urethra and
bladder. A fluid fitting is provided at the distal end for
connection of the drainage catheter to a receptacle, urine
monitoring device or other suitable component.
[0014] The drainage catheter further comprises an anchor assembly
for anchoring the catheter within the urethra. In one aspect of the
invention, the anchor assembly is disposed entirely externally of
the bladder and urethra and is configured to maintain the helical
outer in communication with the bladder. In one embodiment, the
anchor assembly includes a shroud configured to be disposed over
the opening of the urethra of the patient and an engagement between
the shroud and the distal portion of the catheter outside the
urethra. In certain embodiments, this engagement includes a
friction engagement between the shroud and the outer surface of the
distal portion outside the urethra, as may be achieved by forming
the shroud and distal portion of like material. In an alternative
embodiment, the engagement includes a clamping element encircling
the shroud mounted on an outer surface of the distal portion
outside the urethra. This clamping element may be in the form of an
O-ring or encircling strap. In yet another embodiment, the anchor
assembly may include an adhesive strip disposed between the
patient's skin and the shroud when the shroud is disposed over the
opening of the urethra.
[0015] In another aspect of the invention, an indwelling
endourethral drainage catheter is provided that comprises a tubular
body having a proximal end with a blunt tip configured to pass
freely through the urethra into the bladder, a distal end extending
from the proximal end to outside the urethra when the catheter is
indwelling, and a central lumen passing substantially entirely
therethrough. In this aspect, the drainage catheter further
comprises only an external anchor assembly, disposed outside the
bladder and urethra, which is configured to anchor the tubular body
within the urethra with the blunt tip within the bladder. Thus, in
this embodiment, no internal anchor, such as a Foley-type anchor,
is employed to maintain the position of the drainage catheter
within the urethra.
[0016] The present invention further contemplates a method for
advancing an indwelling endourethral drainage catheter along the
urethra of a patient into the bladder that comprises providing a
drainage catheter having at least a spiral proximal portion and a
distal portion, and rotating the proximal portion relative to said
distal portion so that the diameter of the proximal portion
changes. It is contemplated that rotating the proximal portion in
one direction reduces the outer diameter, while rotation in the
opposite direction increases the outer diameter. The reduced
diameter state may be advantageous for advancing the catheter along
the urethra. The larger diameter state of the proximal portion may
be advantageous to bear against an obstruction within the
urethra.
[0017] In yet another method of the invention, a drainage catheter
is provided having a spiral proximal portion and a tubular distal
portion, the catheter defining a central lumen therethrough and the
proximal portion defining an outer channel in fluid communication
with the central lumen. The drainage catheter is advanced into the
urethra until an obstruction is encountered. At this point, the
present invention contemplates rotating the distal portion to
engage the obstruction within the outer channel. Further rotation
of the distal portion may be used to advance the obstruction along
the outer channel into the central lumen. Alternatively, further
rotation of the distal portion may be used to advance the
obstruction along the outer channel toward and into the
bladder.
[0018] It is one object to provide an indwelling ureteral drainage
catheter that avoids the biofilm creep problems associated with
prior drainage catheters. Another object is to provide a drainage
catheter that may be very easily and simply anchored to the
patient.
[0019] One significant benefit of the drainage catheter of the
present invention is that it is easy to deploy while still
providing a stable anchorage within the urethra. A further benefit
is that the catheter provides unique mechanisms for negotiating the
urethra and obstructions that may be encountered as the catheter is
advanced into the bladder. Other objects and benefits of the
invention will become apparent upon consideration of the following
written description and the accompanying figures.
DESCRIPTION OF THE FIGURES
[0020] FIG. 1 is a side partial cross-sectional view of a
Foley-type endourethral catheter in situ.
[0021] FIG. 2 is a side view of an endourethral catheter in
accordance with one embodiment of the present invention.
[0022] FIG. 3 is an enlarged view of a proximal portion of the
catheter shown in FIG. 2 shown in a one state.
[0023] FIG. 4 is an enlarged view of the proximal portion depicted
in FIG. 3, shown in another second state.
[0024] FIG. 5 is a side exterior view of a distal anchor
arrangement for anchoring the catheter of the present invention
within the urethra.
DESCRIPTION OF THE EMBODIMENTS
[0025] For the purposes of promoting an understanding of the
principles of the invention, reference will now be made to the
embodiments illustrated in the drawings and described in the
following written specification. It is understood that no
limitation to the scope of the invention is thereby intended. It is
further understood that the present invention includes any
alterations and modifications to the illustrated embodiments and
includes further applications of the principles of the invention as
would normally occur to one skilled in the art to which this
invention pertains.
[0026] The present invention contemplates an indwelling urinary
drainage catheter 10 shown in FIG. 2 that includes a proximal tip
12 sized and configured to pass through the bladder sphincter into
the bladder. The proximal tip 12 is preferably bullet-nosed or
rounded to facilitate passage through the urethra and to minimize
the potential for damage to the delicate tissues within the
urethra. As shown in FIG. 2, the proximal tip does not incorporate
any retention element, such as the balloon tip of the typical Foley
catheter. Although some form of retention element may be included
in the proximal tip 12, the present invention contemplates
anchoring of the catheter 10 outside the patient's body, as
explained in more detail herein. In addition, the tip may be
provided with openings for fluid flow, although the present
invention does not require openings of this sort. This proximal tip
may be radio-opaque for visibility by x-ray or other imaging source
to verify the position of the tip. In a specific embodiment, the
proximal tip 12 may have a length of about 6 mm.
[0027] The catheter 10 includes a distal tubular portion 14 that
terminates in a fitting 25 configured for attachment to a drainage
container. It can first be appreciated that the catheter 10 has a
length from the proximal tip 12 to the fitting 25 that is
sufficient to at least span the length of the urinary tract from
the inside of the bladder adjacent the bladder sphincter to beyond
the urethral orifice. Preferably, the length of the catheter is
such that the fitting 25 is situated sufficiently beyond the end of
the urethra to readily accessible by medical personnel, such as for
connecting the catheter to a suitable container for receiving urine
drained through the catheter. In addition, the length of the
catheter is sized so that a suitable length of the distal tubular
portion 14 is exposed beyond the end of the urethra to provide a
site for anchoring the catheter. In one embodiment, the catheter is
provided in a single length that is known to accommodate all
patient anatomies. In this embodiment, the catheter has a length of
about 40 cm (16 inches). In an alternative embodiment, it is
contemplated that the catheter 10 may be provided in several
discrete lengths, with an appropriately sized catheter selected
based on the patient's gender and anatomy. The proximal tubular
portion 14 preferably constitutes the majority of the catheter, so
the length of that portion measured from the fitting 25 may be
about 30 cm. It is contemplated that the entire tubular catheter
may contain a radio-opaque coating or strip that will make it
readily visible through external imaging.
[0028] The diameter of the distal tubular portion 14 is also sized
based on standard anatomical dimensions for the urethra. It is
important that the tubular portion 14 fit snugly, but not tightly,
within the urethra. Thus, it is contemplated that the catheter 10
may be provided in several diameters, preferably ranging from 12
French to 30 French in 2 French increments. Thus, the outer
diameters for the selection of catheters preferably range from 4 mm
to 11 mm.
[0029] The distal tubular portion 14 defines an inner lumen 16 for
flow of urine through the catheter. The inner diameter of the lumen
16 must be sufficient for adequate flow. It is therefore
contemplated that the lumen 16 has an inner diameter of at least 3
mm. In one embodiment, the lumen diameter may be the same
regardless of the outer diameter dimension of the tubular portion.
However, since the catheter 10 must have sufficient flexibility to
navigate turns during insertion into the urethra, the tubular wall
thickness is important. Thus, in the preferred embodiment, the wall
thickness of the distal tubular portion 14 is maintained generally
constant regardless of outer diameter dimension. It is contemplated
in one specific embodiment that catheter 10 is formed of a medical
grade polymer, such as Krayton. In other embodiments the catheter
may be formed of latex or silicone and may incorporate hydrogel or
antibiotic impregnations. For this material, it is believed that a
wall thickness of 0.5 mm provides an acceptable degree of
flexibility to navigate turns, while retaining sufficient stiffness
to avoid buckling as the catheter is pushed up the urethra. It is
known that the wall of the urethra itself exerts an inward force
that helps maintain the patency of the catheter 10 as it is
advanced distally. Thus, a thinner wall thickness may be acceptable
in alternative embodiments.
[0030] In accordance with one feature of the invention, the
proximal portion 18 of the drainage catheter 10 constitutes a wound
or spiral tube, as illustrated in FIG. 2. The central lumen 16
passes through the spiral distal portion 18 to provide an
unobstructed flow path for urine. An additional flow path is
provided between the opposite edges 20 of the spiral tube. Thus, as
shown in FIG. 3, an outer channel 22 is defined between the inner
lumen 16 and the outer circumference of the proximal portion 18.
This outer channel 22 provides several beneficial features to the
catheter. First, the outer channel communicates directly with the
bulb or base of the bladder where urine collects at the bladder
sphincter. In prior Foley-type catheters (often having only two
drain islets), the urine pools at this location, rather than fully
draining from the bladder. Any urine that leaks past the anchor
balloon of the Foley catheter bypasses the catheter lumen, which
can result in an embarrassing leakage problem for the patient. As
explained further below, the catheter 10 of the present invention
is anchored to the patient so that the proximal tip 12 is offset
from the bladder sphincter so that the outer channel 22 is always
in fluid communication with the bladder, even at the typical
pooling location.
[0031] A second feature of the spiral proximal portion 18 is that
the outer channel creates a vortex effect as urine drains through
that the channel and enters the inner lumen 16. This vortexing of
the fluid helps hold the urethra open and overcomes surface tension
of fluids pooled in dead spaces in the bladder or urethra.
Vortexing fluids better maintain equalized pressures proximally and
distally providing for optimal forward flow. Moreover, this vortex
flow helps clean the wall of the urethra open to the channel,
thereby retaining the ability to flush contagion or bacteria as
through normal urination.
[0032] A third feature provided by the spiral proximal portion 18
is the ability to achieve multiple states, as seen by comparing the
views of FIGS. 3 and 4. As shown in FIG. 3, the spiral proximal
portion 18 may have a first state A in which the coil is tightly
wound with the edges 20 effectively in contact with each other.
This is accomplished by the operator using a continuous gentle
rotational force in a clockwise manner while inserting, similar to
using a screwdriver to screw in a screw. This state A may occur as
the catheter is maneuvered up the urethra and into the bladder to
improve the axial rigidity of the catheter.
[0033] Once the proximal tip 12 is properly located inside the
bladder sphincter, the spiral proximal portion 18 may be expanded
to the second state B, also shown in FIG. 3. This secondary state
may be accomplished by reversing the gentle rotational force to the
counter-clockwise direction. In this state, the circumferential
channels 22 are opened between the edges 20 and in communication
with the drainage lumen 16. It is contemplated that the spiral
proximal portion may be pre-positioned in this state B and inserted
into the urethra expanded as shown in FIG. 2. Alternatively, the
proximal portion 18 may be inserted in the contracted state A and
then expanded to state B in situ. This later expansion can be
accomplished by advancing a stylet through the lumen 16 until it
contacts the underside of the proximal tip 12. While holding the
distal end of the catheter 10 outside the patient, slightly pushing
the stylet will cause the spiral edges 20 to separate to state
B.
[0034] In this state B one beneficial attribute may be appreciated
for the present invention. In particular, the wider channels 22, as
depicted in FIG. 3, may generate an auger effect to dislodge and
convey an obstruction of the urethra. Thus, in one embodiment, the
catheter may be rotated with the spiral proximal portion 18 in
state B to initially engage an obstruction. With the obstruction
lodged within the outer channel 22, the catheter may be advanced
into the bladder. At this point, the catheter may be rotated
clockwise so that the obstruction is augured upward into the
bladder and clear of the urethra. Alternatively, the catheter may
be rotated counterclockwise to propel the obstruction into the
central lumen 16 where it may be flushed with urine flowing through
the catheter. In this latter case, the obstruction must be much
smaller than the 3 mm inner diameter of the lumen 16 of the
catheter.
[0035] A third state C, illustrated in FIG. 4 is intended as a
temporary measure to address problems with insertion. In this state
C, the spiral proximal portion 18 is rotated relative to the distal
tubular portion 14 so that the outer diameter of the distal portion
is different from the fixed outer diameter of the remainder of the
catheter. To accomplish the transition to state C it is necessary
that the tip be restrained in some manner. Thus, the tip may engage
an obstruction within the urethra to, in effect, anchor it
temporarily. Alternatively, a stylet may be inserted to engage and
prevent movement of the proximal tip 12 as the remainder of the
catheter is rotated. As shown in FIG. 4, the spiral portion 18 can
have a larger diameter in state C than the remainder of the
catheter. This larger diameter may be obtained by rotating the
distal-most end of the distal portion 18 counterclockwise relative
to the remainder of the proximal portion. With the tip held in
place, and with this counterclockwise rotation, each coil of the
spiral portion expands to a larger diameter. In a specific
embodiment, the state C contemplates an expanded outer diameter of
14 mm relative to the 10-11 mm diameter of the normal state A shown
in FIG. 3. This enlarged diameter may be used to help open the
lumen of the urethra or facilitate removal of an obstruction in the
urethra.
[0036] Alternatively, the distal portion may be rotated in the
clockwise direction to reduce the diameter of the proximal-most
portion of the spiral portion 18. This smaller diameter may help
navigate the catheter past an obstruction in the urethra. In
addition, the reduced diameter in effect increases the rigidity of
the spiral proximal portion which may help passage up the urethra.
Again, expansion and contraction of the outer diameter can only
occur if the tip is held immovable.
[0037] Transition of the spiral proximal portion 18 to the enlarged
or reduced diameter of state C may be accomplished by first
engaging the proximal tip 12 to hold the tip against rotation.
Alternatively, a stylet having a blunt tip may thus be advanced
through the catheter until it comes into frictional contact with
the interior of the proximal tip. As a further alternative, the
inner surface of the proximal tip may be provided with an indexing
feature to be engaged by a complementary feature on the tip of the
stylet. With the proximal tip 12 held against rotation, rotation of
the catheter in one direction or the other will produce a
commensurate change in outer diameter of the spiral proximal
portion 18.
[0038] As indicated above, one beneficial feature of the present
invention is that the urinary drainage catheter 10 is anchored
externally, rather than internally as with the typical Foley-type
catheter. In one embodiment for anchoring to a male patient,
illustrated in FIG. 5, a condom catheter sheath or shroud 50 is
used to anchor the endourethral catheter 10. The condom catheter
shroud 50 is configured to fit over the end of the penis. The
condom catheter shroud 50 includes an opening 51 that is adapted to
receive an external drainage tube in a known manner. In accordance
with the present invention, the condom catheter shroud is mounted
on the penis with the proximal portion 14 of the drainage catheter
10 extending through the opening 51.
[0039] In one embodiment, the condom catheter shroud may engage the
penis in a known manner. However, it is believed that in many cases
this engagement is not sufficient to prevent movement of the
drainage catheter 10 along the urethra. It is therefore
contemplated in one specific embodiment that the condom catheter
shroud is anchored to the skin of the shaft of the penis, such as
by an adhesive strip 52. The adhesive strip is preferably
configured according to the adhesive attachment disclosed in
co-pending patent application Ser. No. 11/343,661, entitled
"Adhesive Attachment and Removal Device", filed on Jan. 31, 2006,
in the name of a common inventor to the present application. This
application Ser. No. 11/343,661, the entire disclosure of which is
incorporated herein by reference, discloses an double-sided
adhesive strip 52 with one surface adapted for removable engagement
to the skin of the penis, as shown in FIG. 5. The opposite surface
is adapted to adhere to the inside of the condom catheter shroud
50, whether removable therefrom or not. The adhesive strip
disclosed in this co-pending application thus provides a
fluid-resistant attachment for the shroud to prevent it from
sliding relative to or dislodging from the penis.
[0040] With the condom catheter thus anchored to the penis, the
next aspect of the anchor system of the present invention is to
anchor the drainage catheter 10 to the condom catheter shroud. In
one embodiment, it is contemplated that the outer surface 15 of the
drainage catheter 10 and the inner surface of the shroud 50 are
formed of the same polymeric material. It is known that certain
polymers, such as silicone, exhibit strong adherence between like
material surfaces. Thus, in this embodiment, at least the proximal
portion 14 of the catheter 10 is formed of the same material as the
condom catheter shroud 50. The end of the shroud at the opening 51
may be rolled onto the outer surface 15 of the proximal portion 14
in the same way that the condom catheter shroud is rolled onto the
shaft of the penis.
[0041] Alternatively, or in addition, a retention element 54 may be
provided to securely fasten the condom catheter shroud around the
drainage catheter. This retention element 54 may be in the form of
an O-ring, strap or a circumferential clamp. It is further
contemplated that other forms of attachment between the condom
catheter shroud 50 and the drainage catheter 10 are contemplated,
including more permanent attachment such as adhering or heat
sealing the two surfaces together. Since the condom catheter shroud
50 is removably mounted to the penis, permanent attachment of the
drainage catheter to the shroud does not affect the ability to
remove the entire assembly from the patient.
[0042] In the present disclosed embodiments, a condom catheter
shroud is used to anchor the drainage catheter 10 of the present
invention to the patient. However, it is contemplated that other
means for anchoring the catheter may be used. For instance, the
proximal portion of the catheter may be attached to the skin of the
penis, abdomen or inner thigh of the patient by medical tape.
[0043] In yet another embodiment, the endourethral catheter may be
anchored externally to the female anatomy by way of an attachment
to the skin of the perineum, pelvis, or inner thigh. In one
embodiment, the attachment is by way of an adhesive strip utilizing
the technology disclosed in the application Ser. No. 11/343,661
incorporated by reference above. The adhesive strip may be used to
adhere a soft pliable shroud to adjacent available skin of a female
patient, while the drainage catheter is carried by the shroud.
Alternatively, the shroud may be carried on the patient by a strap
arrangement.
[0044] It can be noted that attachment of the anchoring shroud,
such as shroud 50, to the patient typically requires treatment of
the skin surrounding the urethra with a sterilizing bath, such as
povodine or betadine. Thus, when the shroud and drainage catheter
are anchored to the patient, the area around the urethra has been
cleansed, thereby significantly reducing the availability of
bacteria to participate in the biofilm creep discussed above. In
the case of the male condom catheter, once the shroud 50 is
attached to the skin of the penis by the adhesive strip 52 the
drainage catheter 10 is, in effect, hermetically sealed which will
significantly inhibit incursion of bacteria into the urethra. Even
in the case of a shroud adapted for attachment to the female
anatomy, the same sterilization techniques may be observed to
reduce the formation of bacteria at the site of the drainage
catheter.
[0045] As shown in FIG. 5, the distal end 25 of the endourethral
drainage catheter 10 provides a fitting for engaging another
fitting R. In one embodiment, the two fittings are in the form of a
Luer connection. It is contemplated that the mating fitting R may
be connected to a urine receptacle, to a flow valve or to flow
monitoring or sampling tubing.
[0046] In one embodiment of the invention, it is contemplated that
the entire catheter 10 is formed from a common tube. Thus, the
proximal end of the tubing may be heat molded into the tip
configuration described above. The spiral proximal portion may be
formed by cutting a spiral groove from the proximal tip to a
predetermined distance toward the distal end of the tubing.
Alternatively, the proximal tip 12 may be separately affixed to the
spiral proximal portion 18 of the catheter, such as by heat sealing
or adhering. In another embodiment, the distal portion 14 and the
spiral proximal portion 18 may be co-extruded, or formed using a
dual shot injection molding technique.
[0047] While the invention has been illustrated and described in
detail in the drawings and foregoing description, the same should
be considered as illustrative and not restrictive in character. It
is understood that only the preferred embodiments have been
presented and that all changes, modifications and further
applications that come within the spirit of the invention are
desired to be protected.
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