U.S. patent application number 15/367876 was filed with the patent office on 2017-03-23 for ureteral endoluminal device.
The applicant listed for this patent is Cook Medical Technologies LLC. Invention is credited to Steven J. CHARLEBOIS, Steven L. PENDLETON.
Application Number | 20170079818 15/367876 |
Document ID | / |
Family ID | 49911242 |
Filed Date | 2017-03-23 |
United States Patent
Application |
20170079818 |
Kind Code |
A1 |
PENDLETON; Steven L. ; et
al. |
March 23, 2017 |
URETERAL ENDOLUMINAL DEVICE
Abstract
An endoluminal medical device includes a cannula, the cannula
having a proximal end and a distal end; an abrasion member having a
series of struts interconnected by a series of bent segments
forming a plurality of prongs attached to the cannula, the abrasion
member having a first section and a second section; where the
prongs of the first section of the abrasion member extend radially
outward from the cannula.
Inventors: |
PENDLETON; Steven L.;
(Spencer, IN) ; CHARLEBOIS; Steven J.; (West
Lafayette, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cook Medical Technologies LLC |
Bloomington |
IN |
US |
|
|
Family ID: |
49911242 |
Appl. No.: |
15/367876 |
Filed: |
December 2, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14136975 |
Dec 20, 2013 |
9539127 |
|
|
15367876 |
|
|
|
|
61746895 |
Dec 28, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 27/008 20130101;
A61F 2250/0067 20130101; A61F 2/95 20130101; A61F 2002/048
20130101; A61M 2205/0205 20130101; A61F 2210/0071 20130101; A61F
2/04 20130101 |
International
Class: |
A61F 2/95 20060101
A61F002/95; A61M 27/00 20060101 A61M027/00; A61F 2/04 20060101
A61F002/04 |
Claims
1. An endoluminal medical device to introduce an abrasion to the
urothelium, comprising a cannula, the cannula having a proximal end
and a distal end; an abrasion member comprising a series of struts
interconnected by a series of bent segments forming a plurality of
prongs attached to the cannula, the abrasion member having a first
section and a second section; where the prongs of the first section
of the abrasion member extend radially outward from the
cannula.
2. The endoluminal medical device of claim 1, wherein the first
section of the abrasion member comprises five prongs.
3. The endoluminal device of claim 2, wherein the prongs of the
first section of the abrasion members have generally star shaped
configuration.
4. The endoluminal device of claim 1, wherein the abrasion member
comprises a shape-memory material.
5. The endoluminal device of claim 1, wherein the bent segments of
the abrasion member have a generally circular configuration.
6. The endoluminal device of claim 1, wherein the prongs of the
second section of the abrasion member are disposed within an
interior surface of the cannula.
7. The endoluminal device of claim 1, wherein the prongs of the
second section of the abrasion member are disposed on an outer
surface of the cannula.
8. The endoluminal device of claim 1, wherein the abrasion member
is integrally formed with the cannula.
9. A stent for placement in the ureter, comprising, a tubular
housing having a proximal end, a distal end, and a lumen
longitudinally disposed therethrough; at least one abrasion member
positioned on the tubular housing; where at least a portion of the
abrasion member extends radially outward from the housing and is
configured to engage with the urothelium layer of the ureter.
10. The stent of claim 9, wherein the at least one abrasion member
is positioned distal of the ureteropelvic junction.
11. The stent of claim 9, wherein the at least one abrasion member
comprises a plurality of prongs distributed about the distal end of
the stent.
12. The stent of claim 11, wherein the plurality of prongs have a
pointed configuration.
13. The stent of claim 11, wherein the plurality of prongs have a
generally flattened surface.
14. The stent of claim 11, wherein the plurality of prongs have a
generally concave configuration.
15. The stent of claim 9, wherein the abrasion member comprises a
series of struts interconnected by a series of bent segments
forming a plurality of prongs attached to the cannula, the abrasion
member having a first section and a second section.
16. The stent of claim 15, wherein the bent sections of the
abrasion members have a generally circular configuration.
17. The stent of claim 15, wherein the bent sections of the
abrasion members have a generally straight configuration.
18. The endoluminal device of claim 9, wherein the at least one
abrasion member is disposed on the distal end of the tubular
housing.
19. The endoluminal device of claim 9, wherein the abrasion member
comprises a tubular wire removeably disposed within the lumen of
the substantially tubular housing, the tubular wire comprising a
plurality of projections configured to be positioned within a
plurality of openings on the tubular housing.
20. A method of introducing an abrasion to the urothelium layer of
the ureter, comprising providing an endoluminal medical device, the
endoluminal device comprising a tubular housing having a proximal
end, a distal end, and a lumen longitudinally disposed
therethrough; at least one abrasion member comprising a series of
struts interconnected by a series of bent segments forming a
plurality of prongs attached to the tubular housing, the abrasion
member having a first section and a second section; where the
prongs of the first section of the abrasion member extend radially
outward from the housing introducing the endoluminal device into
the ureter; and abrading the urothelium layer of the ureter with
the endoluminal device.
Description
RELATED APPLICATIONS
[0001] The present application claims priority to U.S. application
Ser. No. 14/136,975 filed Dec. 20, 2013, which claims priority to
U.S. Provisional Patent Application Ser. No. 61/746,895 filed Dec.
28, 2012, the entirety of which is hereby incorporated by
reference.
TECHNICAL FIELD
[0002] The invention relates generally to medical devices and,
particularly, medical devices that can be used in a technique for
more readily introducing drug eluting stents useful for urinary
drainage.
BACKGROUND
[0003] Minimally-invasive surgery has evolved to a point where
procedures that were unimaginable a few years ago are now routinely
performed on a daily basis. Indwelling ureteral stents have been
widely used for years. Such stents are placed in the ureter, which
is the duct between the kidney and the bladder, for the purpose of
establishing and/or maintaining an open, patent flow of urine from
the kidney to the bladder.
[0004] Ureteral stents may be used to retain patency of the
ureteral lumen and to continue normal urinary drainage following
the treatment and removal of stones and calculi from kidneys and
ureters. To treat this condition, several individual steps are
involved. In one procedure, these steps include placing a
relatively narrow wire guide through a urethra and a bladder, and
then through the ureter and into the kidney. After the wire guide
is placed, a catheter is run along the wire guide, dilating the
body passage (the urethra and the ureter) as it moves down the wire
guide. The access sheath also dilates the body passages as it moves
from outside the body, through the urethra, and into the ureter,
down the desired location, and into or very near the kidney.
[0005] The physician may then remove calculi and stones through the
access sheath, using a grasper, a retrieval basket or other device.
The access sheath protects the ureter from repeated passage of the
retrieval device while the stones or calculi are removed. After the
stones are removed, the ureteral stent may be placed into the
ureter through the access sheath, using the catheter or a pushing
tube to position the stent.
[0006] The typical ureteral stent can be composed of various
radiopaque polymers, including polyethylene, silicone,
polyurethane, and thermoplastic elastomers. These stents are
retained in the ureter by a retentive anchoring portion, such as a
curved shape, pigtail, coil, J-shape, or hook configuration, at
either end of the stent that engages the walls of the bladder and
the kidney, respectively. The stent is resilient to allow it to be
straightened for insertion into a body passageway and returned to
its predetermined retentive anchoring shape when in situ.
[0007] There can be problems, however, with ureteral stents, due to
pain and discomfort felt by patients. An attempt to reduce problems
associated with pain and discomfort to the patient may be addressed
through the introduction of pharmacologically active agents in
conjunction with the ureteral stent. However, studies have
demonstrated that intravesical drug delivery can be limited by the
low permeability of the urothelial layer. As such, the urothelial
layer of the ureter may serve as a significant barrier to the
introduction of pharmacological active agent into the tissue of the
ureter. In addition, more of the pharmacological active agent may
elute into the urine of the patient instead of the tissues of the
ureter, which limits the effectiveness of the pharmacological
active agent within the patient.
BRIEF SUMMARY
[0008] In one aspect, an endoluminal medical device includes a
cannula, the cannula having a proximal end and a distal end; an
abrasion member having a series of struts interconnected by a
series of bent segments forming a plurality of prongs attached to
the cannula, the abrasion member having a first section and a
second section; where the prongs of the first section of the
abrasion member extend radially outward from the cannula. In some
embodiments, the first section of the abrasion member includes five
prongs. In other embodiments, the bent segments of the abrasion
member have a generally circular configuration.
[0009] In another aspect, an endoluminal medical device, including
a tubular housing having a proximal end, a distal end, and a lumen
longitudinally disposed therethrough; at least one abrasion member
having a series of struts interconnected by a series of bent
segments forming a plurality of prongs attached to the tubular
housing, the abrasion member having a first section and a second
section; where the prongs of the first section of the abrasion
member extend radially outward from the housing, and where the bent
segments of the prongs of the first section are configured to
engage with the urothelium of the ureter. In some embodiments, the
abrasion member comprises a shape-memory material.
[0010] In yet another aspect, a stent for placement in the ureter,
includes a tubular housing having a proximal end, a distal end, and
a lumen longitudinally disposed therethrough; at least one abrasion
member positioned on the tubular housing; where at least a portion
of the abrasion member extends radially outward from the housing
and is configured to engage with the urothelium of the ureter. In
some embodiments, the first section of the abrasion member
comprises five prongs.
[0011] In still another aspect, a method of introducing an abrasion
to the urothelium layer of the ureter includes providing an
endoluminal medical device, the endoluminal device having a tubular
housing having a proximal end, a distal end, and a lumen
longitudinally disposed therethrough; at least one abrasion member
having a series of struts interconnected by a series of bent
segments forming a plurality of prongs attached to the tubular
housing, the abrasion member having a first section and a second
section; where the prongs of the first section of the abrasion
member extend radially outward from the housing introducing the
endoluminal device into the ureter; and the urothelium layer of the
ureter with the endoluminal device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 depicts an embodiment of an endoluminal medical
device disposed having an abrasion member.
[0013] FIG. 2 depicts a view of an abrasion member for use with the
endoluminal medical device of FIG. 1.
[0014] FIG. 3 depicts an alternative embodiment of an abrasion
member for use with the endoluminal device of FIG. 1.
[0015] FIG. 4 depicts a scope useful for deploying the endoluminal
medical device of FIG. 1.
[0016] FIG. 5 depicts an ureteral stent useful with the endoluminal
medical device embodiment of FIG. 1.
[0017] FIG. 6 depicts an alternative embodiment of an endoluminal
device having an abrasion member.
[0018] FIG. 7 depicts the distal end of the endoluminal device of
FIG. 6.
[0019] FIGS. 8a-8c depict an alternative embodiments of abrasion
members useful with the endoluminal device of FIG. 6.
[0020] FIG. 9a depicts an alternative embodiment of an endoluminal
device having an abrasion member.
[0021] FIG. 9b depicts a portion of the endoluminal device of FIG.
9.
[0022] FIG. 10 depicts results from an ex-vivo porcine ureter
implant test.
DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERRED
EMBODIMENTS
[0023] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention pertains. In case
of conflict, the present document, including definitions, will
control. Preferred methods and materials are described below,
although methods and materials similar or equivalent to those
described herein can be used in the practice or testing of the
present invention. The materials, methods, and examples disclosed
herein are illustrative only and not intended to be limiting.
[0024] The terms "comprise(s)," "include(s)," "having," "has,"
"can," "contain(s)," and variants thereof, as used herein, are
intended to be open-ended transitional phrases, terms, or words
that do not preclude the possibility of additional acts or
structures. The present invention also contemplates other
embodiments "comprising," "consisting of and "consisting
essentially of," the embodiments or elements presented herein,
whether explicitly set forth or not.
[0025] The terms "about" or "substantially" used with reference to
a quantity includes variations in the recited quantity that are
equivalent to the quantity recited, such as an amount that is
insubstantially different from a recited quantity for an intended
purpose or function.
[0026] The term "prosthesis" means any device for insertion or
implantation into, or replacement, for a body part or function of
that body part. It may also mean a device that enhances or adds
functionality to a physiological system. The term prosthesis may
include, for example and without limitation, a stent, stent-graft,
filter, valve, balloon, embolization coil, and the like.
[0027] The term "endoluminal" refers to or describes the internal
or inside of a lumen, duct, and other passageways or cavities
located in a human or other animal body. A lumen or a body
passageway may be an existing lumen or a lumen created by surgical
intervention. As used in this specification, the terms "lumen" or
"body passageway," and "vessel" are intended to have a broad
meaning and encompass any duct (e.g., natural or iatrogenic) or
cavity within the human body and may include, without limitation,
urethral and ureteral passages, blood vessels, respiratory ducts,
gastrointestinal ducts, such as the biliary duct, intestines, the
esophagus, the pericardial cavity, the thoracic cavity, and the
like. Accordingly, the terms "endoluminal device" or "endoluminal
prosthesis" describe devices that can be placed inside or moved
through any such lumen or duct.
[0028] The terms "patient," "subject," and "recipient" as used in
this application may refer to any animal, particularly humans.
[0029] The terms "proximal" and "distal" will be used to describe
opposing axial ends of the ureteral stent, as well as the axial
ends of various component features. The term "proximal" is used to
refer to the end of the ureteral stent (or component thereof) that
is closest to the operator during use of the system. The term
"distal" is used to refer to the end of the ureteral stent (or
component thereof) that is initially inserted into the patient, or
that is closest to the patient during use.
[0030] The term "biocompatible" refers to a material that is
substantially non-toxic in the in vivo environment of its intended
use, and that is not substantially rejected by the patient's
physiological system (i.e., is non-antigenic). This can be gauged
by the ability of a material to pass the biocompatibility tests set
forth in International Standards Organization (ISO) Standard No.
10993 and/or the U.S. Pharmacopeia (USP) 23 and/or the U.S. Food
and Drug Administration (FDA) blue book memorandum No. G95-1,
entitled "Use of International Standard ISO-10993, Biological
Evaluation of Medical Devices Part-1: Evaluation and Testing."
Typically, these tests measure a material's toxicity, infectivity,
pyrogenicity, irritation potential, reactivity, hemolytic activity,
carcinogenicity and/or immunogenicity. A biocompatible structure or
material, when introduced into a majority of patients, will not
cause a significantly adverse, long-lived or escalating biological
reaction or response, and is distinguished from a mild, transient
inflammation which typically accompanies surgery or implantation of
foreign objects into a living organism.
[0031] The term "medical device" means any object that is itself or
that includes a component that is intentionally inserted into the
body of a patient as part of a medical treatment, and that
comprises a structure adapted for introduction into a patient. The
medical device can be a tool, such as, without limitation, a
catheter, a wire guide, a forceps, or a scissors used to affect a
surgical procedure at and/or deliver a second medical device to a
treatment site in a patient. An alternative medical device of the
present invention is one that is commonly intended to be a
temporary or permanent implant, such as a stent.
[0032] The term "implantable" refers to the ability of a medical
device to be positioned, partially or wholly, at a location within
a body of a human or veterinary patient for any suitable period of
time, such as within a vessel. Implantable medical devices can
include devices configured for bioabsorption within a body during
prolonged period of time.
[0033] The term "controlled release" refers to the release of a
material, such as a pharmacologically active ingredient, at a
predetermined rate. A controlled release may be characterized by a
drug elution profile, which shows the measured rate that the
material is removed from a material-containing device in a given
solvent environment as a function of time. A controlled release
does not preclude an initial burst release associated with the
deployment of the medical device. The release may be a gradient
release in which the concentration of the material released varies
over time or a steady state release in which the material is
released in equal amounts over a certain period of time (with or
without an initial burst release).
[0034] The term "pharmacologically active ingredient" refers to any
agent that produces an intended therapeutic effect on the body to
treat or prevent conditions or diseases.
[0035] A more detailed description of the embodiments will now be
given with reference to FIGS. 1-9b. The present invention is not
limited to those embodiments illustrated; it specifically
contemplates other embodiments not illustrated but intended to be
included in the claims.
[0036] FIG. 1 discloses an embodiment of an endoluminal medical
device 10. In this embodiment, the endoluminal medical device 10 is
a cannula 12 comprises a generally tubular body 14 having a
proximal end 16, and a distal end 18. The cannula 12 may be made
from solid rod or from hollow tubing. The cannula 12 may be
composed of any medical grade material having strength suitable for
introduction to the site from which an object is to be retrieved,
and having a configuration designed for secure grasping,
containment and/or removal of the object. Examples of suitable
materials including, but are not limited to, metal such as
stainless steel or Nitinol, polymeric or plastic materials having
fibrous or particulate fillers incorporated in them such as nylons,
polycarbonates, polytetrafluoroethylene, and any other reinforced
or un-reinforced plastic material suitable for the application. The
cannula 12 may have a length and an outer diameter sufficient to
extend through a working channel of medical scope (see FIG. 4), for
which the cannula 12 may be removeably positioned. For example,
cannula may have an outer diameter of about 6 to 7 French in order
to fit within the working channel. Cannula 12 also may comprise a
hydrophilic coating (not shown) overlying its outer surface. The
hydrophilic coating, when applied to the outer surface of cannula,
imparts suppleness and kink resistance to the cannula. The
hydrophilic coating also may provide a lubricated surface to
facilitate movement through the working channel of medical
scope.
[0037] An abrasion member 20 having a plurality of prongs 26 is
positioned on the distal end of the cannula 12. In this embodiment,
the abrasion member 20 is attached separately to the distal end 16
of the cannula 12. The abrasion member 20 may be attached to the
cannula 12 by any suitable means, including, but not limited,
welding, soldering, heat-setting, and adhesives. One of ordinary
skill in the art would understand that the abrasion member 20 may
be attached to the distal end of the cannula through other suitable
means. Further, the abrasion member 20 may be temporarily attached
to the distal end 16 of the cannula 12 or permanently attached to
the cannula 12. In alternative embodiments, the abrasion member 20
may be formed integral with the distal end 16 of the cannula 12.
The medical device 10 may further include an outer sheath (not
shown) disposed about an outer surface of the cannula 12. The outer
sheath may be configured to maintain the prongs 26 of the abrasion
member 20 in a compressed configuration prior to deployment of the
device.
[0038] Referring to FIG. 2, the abrasion member 20 comprises a
first section 22 and a second section 24. The first section 22 and
the second section 24 of the abrasion member 20 each comprise of a
plurality of prongs 26. In the first section, the plurality of
prongs 26 extends radially outward from the distal end of the
cannula at a predetermined angle. The angle formed by the prongs 26
may be equal to or less than about 90 degrees. The prongs 26 of the
second section 24 of the abrasion member 20 are configured to be
placed upon a surface of the cannula 12. In some embodiments, the
prongs 26 of the second section 24 are positioned within an
interior surface of the cannula 12. In other embodiments, the
prongs 26 of the second section 24 are positioned on an outer
surface of the cannula 12. As shown in the figure, the first
section 22 of the abrasion member 20 and the second section 24 of
the abrasion member 20 each have five prongs. In this embodiment,
the prongs 26 of the abrasion member 20 are formed such that the
abrasion member 20 has a generally star shaped configuration. One
of ordinary skill in the art would understand that in alternative
embodiments, other configurations may be suitable for the abrasion
member 20.
[0039] The abrasion member 20 may be made from numerous metals and
alloys. In one example, the abrasion member 20 comprises a
shape-memory material such as a nickel-titanium alloy ("Nitinol").
Moreover, the abrasion member 20 may be formed in a variety of ways
to provide a suitable support structure. For example, the abrasion
members 20 may be made from a woven wire structure, a laser-cut
cannula, individual interconnected rings, or another pattern or
design. While one exemplary arrangement is shown in FIG. 2, it will
be appreciated that the exact number of prongs 26 may be varied.
The prongs 26 of the abrasion member 20 have a plurality of struts
28 which are set at angles relative to each other and are connected
by an elongated bent segment 30. In one example, the prongs 26 may
be configured in the form of in a zigzag configuration in which the
struts are set at angles relative to each other and are connected
by a bent segment having a generally pointed configuration.
[0040] FIG. 3 shows the distal end 18 of the cannula 12 with an
alternative embodiment of the prongs 26 of the first section 22 of
the abrasion member 20. As shown, the prongs 26 of the first
section 24 of the abrasion member 20 is non-symmetrical and the
struts 28 are generally parallel and are connected by a bent
segment 30 having a generally concave arcuate configuration. In
alternative embodiments, the bent segment 30 may have a generally
straight configuration. The prongs 26 are configured to abrade the
urothelium layer of the ureter, such as by scraping or by
scratching. In a preferred embodiment, the prongs 26 of the
abrasion member 20 will abrade the urothelium layer of the ureter
between 1 mm and about 2 mm.
[0041] As shown by FIG. 4, the cannula 12 may be introduced into
the ureter through the use of other medical devices, such as a
scope 32. The scope includes at least one working or operating
channel 34. The working channel 34 extends from the proximal end of
the scope to the distal end of the scope. The working channel 34
may be generally tubular and is configured to receive and deliver
medical devices into the body of a patient. For example,
diagnostic, monitoring, treatment, operating instruments, tools,
and accessories, may be passed. The working channel 34 may be
manufactured from any suitable biocompatible material. Examples of
suitable materials include polyurethane, cellulose acetate,
cellulose nitrate, silicone, polyethylene terephthalate, polyamide,
polyester, polyorthoester, polyanhydride, polyether sulfone,
polycarbonate, polypropylene, high molecular weight polyethylene,
and polytetrafluoroethylene. The working channel 34 may be strong
and resilient and may comprise a single or multi-layer, and may be
composed of or include any material that is flexible, bendable,
pliable, elastic, and stretchable (collectively, "flexible"). In
alternative embodiments, the cannula 12 may be introduced into the
ureter through the use of an access sheath.
[0042] FIG. 5 depicts a stent 40 that may be used in conjunction
with the cannula 12. The ureteral stent 40 may be a "double
pig-tail" variety, such as those available by Cook Urological
Incorporated, Spencer, Ind. The stent is designed to preferably
have a length of about 8 cm to about 30 cm and preferably having
outer diameters in the range of about 1 mm to about 4 mm. Most
preferably, the outer diameters of the stents range from about 1.5
mm to about 3 mm and most preferably the stent will have a wall
thickness in the range of about 0.25 mm to about 1 mm. Other
suitable ureteral stents may be used with this device. Exemplary
embodiments are provided in U.S. Pat. No. 7,550,012, herein
incorporated by reference.
[0043] One or more pharmacologically active agents, such as
medications or drugs, may be placed on the surface of the ureteral
stent 40 in order to assist in patient care and comfort. For
instance, an antimicrobial drug may help to reduce inflammation and
microbial activity in the vicinity of the stent. Analgesics, such
as aspirin or other non-steroidal anti-inflammatory drugs, may also
be applied to the surface to reduce pain and swelling upon
implantation of the stent. Other medications, such as
alpha-blockers, may also be used. Alpha-blockers are drugs that
block receptors in arteries and smooth muscles. In the urinary
tract, alpha-blockers relax the walls of the tract and enhance
urinary flow. Examples of suitable alpha-blockers include, but are
not limited to, doxazosin, alfuzosin, tamsulosin, prazosin, and
terazosin. In a preferred embodiment, the ureteral stent is coated
with doxazosin. Any of these pharmacologically active agents is
preferably applied in a controlled release so that the beneficial
effect of the drug is sustained over a period of at least several
days or weeks. This may be especially helpful in the case where the
stent will remain in place for a considerable length of time.
[0044] In use, a physician may introduce the scope 32 into the
ureter over a wire guide and moves the distal end of the scope 32
into the target site. The physician may then insert the cannula 12
into the working channel 34 of the scope 32 and out of the opening
of the working channel 34 and into the physician's observation
field and working space. During introduction of the cannula 12, the
bent sections 28 of the prongs 26 on the first section 22 of the
abrasion member 20 are placed into contact with the urothelium
layer of the ureter. The physician will reciprocally translate the
abrasion member 20 through the ureter in both the proximal and
distal direction to cause a controlled abrasion to the urothelium
layer of the ureter. After abrading the urothelium, the physician
can remove the cannula 12 through the working channel 34 of the
scope 34. The physician may introduce a drug eluting ureteral stent
40 into the ureter of the patient using an introducer through the
working channel 34 of the scope 32.
[0045] The abrasion caused to the urothelium layer of the ureter of
the patient aids in the uptake of the applied drug treatment to the
patient. Studies have shown that the urothelium provides a
significant barrier to the drug delivery through the ureter. FIG.
10 provides data related to how abrading the urothelium layer of
the ureter may aid in the uptake of the applied treatment by the
patient. The ex vivo study involved placing a drug eluting stent
into porcine ureters obtained from pigs that were slaughtered the
same day of the study. Three of the porcine ureters were abraded by
scraping the urothelium with a steel cannula prior to implantation
of the drug eluting stent. As a control, three porcine ureters were
used which were not abraded. The ureters receiving abrasions are
referred to in the chart as Lot-041912-MECH and the control ureters
are referred to in the chart as Lot-041912.
[0046] A 7 cm doxazosin tube was inserted into 9 cm of each ureter
and stored for approximately eighteen hours at 37 C in screw capped
glass vial which is hydrated with 0.25 ml of phosphate buffered
saline ("PBS") solution. The PBS solution generally had a pH of
7.4. Each glass tube was laid down horizontally and the ureter sits
directly in the PBS solution. Following the 18 hour period, the
doxazosin tubes were removed from the ureters and each ureter was
extracted from the glass vials. The ureters were analyzed using
high performance liquid chromatography ("HPLC") techniques to
determine the amount of drug intake received by each ureter.
[0047] As demonstrated by the data (shown in FIG. 10), the ureters
receiving abrasions demonstrated significantly increased tissue
uptake of the doxazosin drug compared to the control ureters. The
abrasions applied to the urothelium layer allows the ureter to
receive a greater amount of the drug as opposed ureters that do not
receive any abrasions. As such, more of the drug may elute into the
ureteral tissue and less will be lost to elution into the
urine.
[0048] FIG. 6 shows an alternative embodiment of an implantable
endoluminal device medical device 110. As shown, the medical device
110 comprises a ureteral stent 112 having an elongated tubular body
114 having a proximal end 116 and a distal end 118 and a lumen
disposed therethrough. The ureteral stent 112 includes a pigtail
shaped retention mechanism 132 on the proximal end 116. Fluid
openings or passageways 134 are disposed throughout the length of
the ureteral stent 112. The ureteral stent 112 further includes an
abrasion member 120. The ureteral stent 112 is produced from
flexible material which is preferably elastomeric and containing
memory in order that any portion of the stent which is curved will
return to its original shape if straightened during the
implantation procedure. The polymers or elastomers from which the
stent is produced are preferably radiopaque and include
polyethylene, silicone, polyurethane, and thermoplastic elastomer.
The ureteral stent 112 is designed to preferably have a length of
about 8 cm to about 30 cm and preferably having outer diameters in
the range of about 1 mm to about 4 mm. Most preferably, the outer
diameters of the stents range from about 1.5 mm to about 3 mm and
most preferably the stent will have a wall thickness in the range
of about 0.25 mm to about 1 mm. The ureteral stent 112 may be
introduced using a medical device such as a scope or an access
sheath.
[0049] One or more pharmacologically active agents, such as
medications or drugs, may be placed on the surface of the ureteral
stent 112 in order to assist in patient care and comfort. For
instance, an antimicrobial drug may help to reduce inflammation and
microbial activity in the vicinity of the stent. Analgesics, such
as aspirin or other non-steroidal anti-inflammatory drugs, may also
be applied to the surface to reduce pain and swelling upon
implantation of the stent. Other medications, such as
alpha-blockers, may also be used. Alpha-blockers are drugs that
block receptors in arteries and smooth muscles. In the urinary
tract, alpha-blockers relax the walls of the tract and enhance
urinary flow. Examples of suitable alpha-blockers include, but are
not limited to, doxazosin, alfuzosin, tamsulosin, prazosin, and
terazosin. In a preferred embodiment, the ureteral stent is coated
with doxazosin. Any of these pharmacologically active agents is
preferably applied in a controlled release so that the beneficial
effect of the drug is sustained over a period of at least several
days or weeks. This may be especially helpful in the case where the
stent will remain in place for a considerable length of time.
[0050] FIG. 7 shows the distal end 118 of the ureteral stent 112 in
greater detail. As shown, the abrasion member 120 includes a
plurality of prongs 126. The prongs 126 may comprise a series of
struts interconnected by a series of bent segments. In the present
embodiment, the abrasion member 120 may be used to provide an
abrasion to the urothelium of the ureter during placement of the
ureteral stent 112. The abrasion member 120 of the present
embodiment may also be used for retention of the ureteral stent 112
within the ureter of the patient. In particular, the abrasion
member 120 may be placed distal to the ureteropelvic junction of
the patient within the kidney. In alternative embodiments, the
stent may include an additional retention member to retain the
ureteral stent 112 in the desired position.
[0051] FIGS. 8a-8c show alternative embodiments of the distal end
118 of the ureteral stent 112. In these embodiments, a pigtail
shaped retention mechanism 142 is disposed on the proximal end 116
having a plurality of abrasion members 120 disposed on the outer
surface of the pigtail shaped retention mechanism 142. In FIG. 8a,
the abrasion members 120 have a generally pointed configuration.
FIG. 8b shows the abrasion members 120 having a generally flattened
surface. FIG. 8c shows the abrasion members 120 have a U-shaped
valley or trough. The abrasion members 120 are disposed in eight
locations about the surface of the pigtail shaped retention member
142. One of ordinary skill will understand that other
configurations may be suitable for the abrasion members 120.
[0052] In use, the ureteral stent 112 may be implanted or placed in
the ureter by various techniques or procedures. In a preferred
embodiment, the ureteral stent 112 is placed over a wire guide and
followed by the ureteral stent being placed through a scope and up
into the ureter. In another procedure, a wire guide may be first
placed through a scope and into the urethra up into the ureter and
into the kidney. The stent 112 is then fed onto the wire guide and
over the wire guide into the ureter. During introduction of the
ureteral stent 112, the bent sections 128 of the prongs 126 on the
first section 122 of the abrasion member 120 are placed into
contact with the urothelium layer of the ureter. The physician will
reciprocally translate the abrasion member 120 through the ureter
in both the proximal and distal direction to cause a controlled
abrasion to the urothelium layer of the ureter. After abrading the
urothelium layer, the physician positions the abrasion member 120
distal to the ureteropelvic junction in the kidney to help retain
the ureteral stent 112 within the ureter. A positioning catheter
may be used to place the ureteral stent 112 in this procedure where
it is stabilized in the bladder and the wire guide is removed from
the stent 112. The positioning catheter is then removed along with
the wire guide.
[0053] FIGS. 9a and 9b show an alternative embodiment of an
endoluminal medical prosthesis 210. As shown, the prosthesis 210
comprises a ureteral stent 212 having an elongated tubular body 214
having a proximal end 216 and a distal end 218 and a lumen disposed
therethrough. The ureteral stent 212 includes a pigtail shaped
retention mechanism 232 on the proximal end 116 and the distal end
118. The pigtail shaped retention member 232 on the proximal end
218 of the ureteral stent 212 includes an opening. Fluid openings
or passageways 234 are disposed throughout the length of the
ureteral stent 212. The ureteral stent 212 is designed to
preferably have a length of about 8 cm to about 30 cm and
preferably having outer diameters in the range of about 1 mm to
about 4 mm. Most preferably, the outer diameters of the stents
range from about 1.5 mm to about 3 mm and most preferably the stent
will have a wall thickness in the range of about 0.25 mm to about 1
mm. A wire 240 having a plurality of abrasion members 220 is
removeably positioned within the lumen of the ureteral stent 212
through the opening on the proximal end of the ureteral stent 212.
As shown in FIG. 9b, the abrasion members 220 on the wire 240 are
configured to fit within the fluid openings 234 on the ureteral
stent 212. The abrasion members 220 may be distributed throughout
the entire length of the wire 240 or in specific portions of the
wire 240. In some embodiments, the abrasion members 220 may only be
positioned on a distal end of the wire 240 such that they are
positioned at a distal portion of the ureteral stent 212.
[0054] One or more pharmacologically active agents, such as
medications or drugs, may be placed on the surface of the ureteral
stent 212 in order to assist in patient care and comfort. For
instance, an antimicrobial drug may help to reduce inflammation and
microbial activity in the vicinity of the stent. Analgesics, such
as aspirin or other non-steroidal anti-inflammatory drugs, may also
be applied to the surface to reduce pain and swelling upon
implantation of the stent. Other medications, such as
alpha-blockers, may also be used. Alpha-blockers are drugs that
block receptors in arteries and smooth muscles. In the urinary
tract, alpha-blockers relax the walls of the tract and enhance
urinary flow. Examples of suitable alpha-blockers include, but are
not limited to, doxazosin, alfuzosin, tamsulosin, prazosin, and
terazosin. In a preferred embodiment, the ureteral stent is coated
with doxazosin. Any of these pharmacologically active agents is
preferably applied in a controlled release so that the beneficial
effect of the drug is sustained over a period of at least several
days or weeks. This may be especially helpful in the case where the
stent will remain in place for a considerable length of time.
[0055] In use, the ureteral stent 212 may be implanted or placed in
the ureter by various techniques or procedures. In a preferred
embodiment, the ureteral stent 212 is placed over a wire guide and
followed by the ureteral stent being placed through a scope and up
into the ureter. In another procedure, a wire guide may be first
placed through a scope and into the urethra up into the ureter and
into the kidney. The ureteral stent 212 is then fed onto the wire
guide and over the wire guide into the ureter. During introduction
of the ureteral stent 212, the abrasion members 220 positioned on
the wire 240 are placed into contact with the urothelium layer of
the ureter. The physician will reciprocally translate the abrasion
member 220 through the ureter in both the proximal and distal
direction to cause a controlled abrasion to the urothelium layer of
the ureter. After abrading the urothelium layer the urothelium
layer and ureteral stent is placed in the desired position, the
physician may remove the wire 240 from the interior of the ureteral
stent 212 and physician position the pigtail shaped retention
member 232 on the distal end 118 of the ureteral stent 212 distal
to the ureteropelvic junction in the kidney to help retain the
ureteral stent 212 within the ureter. A positioning catheter may be
used to place the ureteral stent 212 in this procedure where it is
stabilized in the bladder and the wire guide is removed from the
stent 212. The positioning catheter is then removed along with the
wire guide.
[0056] An endoluminal medical device, comprising, a tubular housing
having a proximal end, a distal end, and a lumen longitudinally
disposed therethrough; at least one abrasion member comprising a
series of struts interconnected by a series of bent segments
forming a plurality of prongs attached to the tubular housing, the
abrasion member having a first section and a second section; where
the prongs of the first section of the abrasion member extend
radially outward from the housing, and where the bent segments of
the prongs of the first section are configured to engage with the
urothelium of the ureter.
[0057] Throughout this specification various indications have been
given as to preferred and alternative embodiments of the invention.
However, the foregoing detailed description is to be regarded as
illustrative rather than limiting and the invention is not limited
to any one of the provided embodiments. It will be evident to one
skilled in the art that modifications and variations may be made
without departing from the spirit and scope of the invention.
Changes in form and in the proportion of parts, as well as the
substitution of equivalents, are contemplated as circumstances may
suggest and render expedience; although specific terms have been
employed, they are intended in a generic descriptive sense only and
not for the purpose of limiting the scope of the invention set
forth in the following claims. Moreover, the device is not limited
to any specific dimension or material discussed above, nor is the
device limited to being used with saline or an image contrast fluid
alone.
* * * * *