U.S. patent application number 13/168345 was filed with the patent office on 2012-02-09 for tissue plug.
Invention is credited to Sherif A. Eskaros, John M. Herman.
Application Number | 20120035644 13/168345 |
Document ID | / |
Family ID | 45556684 |
Filed Date | 2012-02-09 |
United States Patent
Application |
20120035644 |
Kind Code |
A1 |
Eskaros; Sherif A. ; et
al. |
February 9, 2012 |
Tissue Plug
Abstract
Tissue plugs for occlusion of hollow anatomical structures and
methods for their use are provided.
Inventors: |
Eskaros; Sherif A.; (Elkton,
MD) ; Herman; John M.; (Elkton, MD) |
Family ID: |
45556684 |
Appl. No.: |
13/168345 |
Filed: |
June 24, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61370263 |
Aug 3, 2010 |
|
|
|
61490239 |
May 26, 2011 |
|
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Current U.S.
Class: |
606/198 ;
606/191 |
Current CPC
Class: |
A61B 2017/00606
20130101; A61B 2017/00004 20130101; A61B 2017/00575 20130101; A61B
17/0057 20130101; A61B 2017/00336 20130101; A61B 2017/22038
20130101; A61B 2017/00654 20130101; A61B 2017/00619 20130101; A61B
2017/00942 20130101; A61B 2017/00898 20130101; A61B 2017/00641
20130101; A61B 2017/00659 20130101 |
Class at
Publication: |
606/198 ;
606/191 |
International
Class: |
A61M 29/00 20060101
A61M029/00 |
Claims
1. A device for treatment of hollow anatomical structures
comprising: a. a first portion; b. a first axial member which is
oriented through a hollow anatomical structure and is connected to
the first portion; and c. at least one occluding member which
adjusts upon said first axial member to fill the hollow anatomical
structure.
2. The device of claim 1 wherein the first portion is in the form
of a fixed point or an anchoring member.
3. The device of claim 2 wherein the first portion is in the form
of a substantially planar anchoring member.
4. The device of claim 1 wherein the occluding member adjusts
within the hollow anatomical structure upon longitudinal
translation along the axial member.
5. The device of claim 4 further comprising a second portion
connected to said first axial member.
6. The device of claim 5 wherein the first portion is either
fixedly or slidably connected to the first axial member and wherein
the second portion is either fixedly or slidably connected to the
first axial member provided that the first portion and the second
portion are not both fixedly attached to the first axial
member.
7. The device of claim 4 further comprising a second axial
member.
8. The device of claim 7 further comprising a second portion that
is connected to said second axial member.
9. The device of claim 8 wherein the first portion is fixedly or
slidably connected to the first axial member and the second portion
is fixedly or slidably connected to the second axial member
10. The device of claim 5 wherein the first portion and the second
portion are in the form of a fixed point or an anchoring
member.
11. The device of claim 10 wherein the first portion and the second
portion are in the form of a substantially planar anchoring
member.
12. The device of claim 1 wherein the at least one occluding member
is bioabsorbable.
13. The device of claim 1 further comprising a collar attached to
at least one end of the at least one occluding member.
14. The device of claim 13 wherein said collar reduces the freedom
of movement of any components which may move or slide along the
first axial member after deployment.
15. The device of claim 14 wherein said collar reduces the freedom
of movement via chemical, mechanical or frictional means.
16. The device of claim 1 further comprising a first portion
reinforcement element.
17. The device of claim 5 further comprising first portion and
second portion reinforcement elements.
18. The device of claim 2 wherein the device is adapted for
catheter delivery.
19. The device of claim 18 wherein said at least one occluding
member is collapsible from an initial state with an initial length
to a deployed state with a length shorter than said initial length
and wherein said deployed occluding member conforms to the geometry
of a tract formed by the hollow anatomical structure.
20. The device of claim 19 wherein said first portion is an
anchoring member which is expandable from an initial state with an
initial diameter to a deployed state with a diameter greater than
said initial diameter.
21. The device of claim 20 wherein the device is adapted to be
undeployable and redeployable.
22. The device of claim 5 wherein the device is adapted for
catheter delivery.
23. The device of claim 22 wherein said at least one occluding
member is collapsible from an initial state with an initial length
to a deployed state with a length shorter than said initial length
and wherein said deployed occluding member conforms to the geometry
of a tract formed by the hollow anatomical structure.
24. The device of claim 23 wherein said first portion and said
second portion are anchoring members which are expandable from an
initial state with an initial diameter to a deployed state with a
diameter greater than said initial diameter.
25. The device of claim 24 wherein the device is adapted to be
undeployable and redeployable.
26. A method of occluding a hollow anatomical structure by the
steps of: a. providing an implantable device comprising at least a
first portion and at least one occluding member; b. positioning the
first portion adjacent to one end of the hollow anatomical
structure; and c. bunching the occluding member and thereby filling
a tract formed by the hollow anatomical structure while maintaining
the position of the first portion.
27. The method of claim 21 wherein the implantable device further
comprises a second portion.
28. The method of claim 22 wherein the second portion is positioned
at the opposite end of the tract of the hollow anatomical structure
upon bunching of the at least one occluding member.
29. A device for treatment of hollow anatomical structure
comprising: a. a first portion with an aperture extending there
through; b. a first axial member which is oriented through a hollow
anatomical structure and is connected to the first portion; and c.
at least one occluding member which adjusts upon said axial portion
to fill the hollow anatomical structure.
30. The device of claim 29 wherein the aperture is adapted for use
with a guidewire.
31. The device of claim 10 wherein the first portion and the second
portion are anchoring members and wherein at least one anchoring
member is non-bioabsorbable.
32. The device of claim 31 wherein a non-bioabsorbable anchoring
member is adapted to be positioned within a gastrointestinal tract
of a patient.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Ser. No. 61/370,263
filed Aug. 3, 2010 and U.S. Ser. No. 61/490,239 filed May 26,
2011.
FIELD OF THE INVENTION
[0002] The present invention relates to a medical device for
occluding hollow anatomical structures and methods for use of these
devices in occluding hollow anatomical structures.
BACKGROUND OF THE INVENTION
[0003] A variety of abnormal passages called fistula or fistulae
can occur in the mammalian body. Fistulae may be caused by, for
example, infection, congenital defects, inflammatory bowel diseases
such as Crohn's disease, irradiation, trauma, cancer, childbirth,
and surgical procedures. Fistulae may occur in the circulatory,
respiratory, digestive, genitourinary, and musculoskeletal systems.
Examples include, but are not limited to, vesico-vaginal,
urethro-vaginal, tracheo-esophageal, gastro-cutaneous, anorectal
(ano-cutaneous), recto-vaginal, recto-vesical, recto-urethral and
recto-prostatic fistulae. The most common fistulae occur from the
intestine to an opening in the skin.
[0004] Various methods devices for repairing fistula have been
described. The exact procedure and/or device will depend on the
type of fistula being treated. One technique for treating fistulae
involves the use of a plug-like device.
[0005] The Cook SIS Fistula Plug is manufactured from porcine small
intestinal submucosa (SIS) and is intended for repair of anal,
rectal, and enterocutaneous fistulae. The modified SIS Fistula
Plug, also manufactured from porcine small intestinal submucosa, is
supplied in a tapered configuration with a button to provide
increased retention of the plug and improved blockage of the
fistula.
[0006] The GORE BIO-A.RTM. Fistula Plug is intended for use in
anorectal fistulae. This plug device has a three-dimensional disk
with tube mesh design and is comprised of the synthetic
bioabsorbable material polyglycolic acid:trimethylene carbonate
(PGA:TMC).
[0007] Additional fistula plugs and/or devices for occluding hollow
anatomical structures are described in, for example, published U.S.
Application Nos. 2008/0051831, 2008/0245374, 2009/0054927,
2009/0125119, and 2010/0086578, and U.S. Pat. No. 7,485,087.
SUMMARY OF THE INVENTION
[0008] The present invention provides medical devices for occlusion
of hollow anatomical structures. It should be understood that
devices of the present invention may be suitable for occlusion of
any hollow anatomical structure such as a perforation, leak, tear,
orifice, or aperture within the human body in need of treatment,
which may be congenital or naturally occurring or as a result of
injury, trauma, disease, etc. It should be further appreciated that
the medical devices of the present invention may be used to occlude
or plug a fistula or can be used in any other naturally occurring
hollow anatomical structures, including but not limited to veins,
arteries, coronary structures, pulmonary structures, tubular
structures associated with reproductive organs, and the like. In
one embodiment in the present invention, the device is used to
treat gastrointestinal leaks and/or fistulae.
[0009] In one embodiment, devices of the present invention are used
as a plug for a fistula or a gastrointestinal leak wherein the
device comprises a first portion, an axial member which may be
oriented through a fistula space and is connected to the first
portion, and an occluding member which adjusts upon such axial
portion to fill said space.
[0010] In another embodiment, the device comprises a first portion,
such as an anchoring portion with a central aperture, an occluding
member having a distal end and a proximal end and an interior and
an exterior; the first portion positioned adjacent to the proximal
end of the exterior of the occluding member; and an axial member
attached to the interior distal end of the occluding member,
wherein the axial member extends through the aperture of the
anchoring portion. Upon pulling of the axial member in a direction
further proximal to the anchoring portion, the distal end of the
occluding member moves toward the proximal end of the occluding
member thereby collapsing or bunching the occluding member. In an
alternative embodiment, tensioning of the axial member with
concurrent pushing of the occluding member will result in the
collapsing or bunching effect sought. The resultant device,
primarily by virtue of the occluding member, fills the hollow
anatomical structure. In one embodiment the occluding member is a
hollow tubular occluding member and the anchoring portion may be in
the form of a planar anchoring means, such as a disk. The anchoring
portion can thus serve to clamp or seal tissue, generally at the
openings of the hollow anatomical structure, proximate to the
anchoring portion.
[0011] Another aspect of the present invention relates to a method
for occluding a hollow anatomical structure with the devices of the
present invention. In one embodiment, the occluding device is
positioned in a hollow anatomical structure so that the occluding
member is inside the hollow anatomical structure and the first
portion is at one opening of the hollow anatomical structure. The
axial member of the device is then pulled in a direction away from,
or more proximal to, the first portion, while the first portion is
held in place upon the opening of the hollow anatomical structure,
such that the distal end of the occluding member moves toward the
proximal end of the occluding member, thereby collapsing or
bunching the occluding member at least within the hollow anatomical
structure. The device is thus able to fill the void created by the
hollow anatomical structure and, optionally, seals tissue of the
hollow anatomical structure near the first portion to secure the
device in place.
BRIEF DESCRIPTION OF THE FIGURES
[0012] FIG. 1 provides a perspective view of an embodiment of a
device of the present invention prior to deployment.
[0013] FIG. 2 provides a perspective view of an embodiment of the
device of the present invention after deployment via pulling of the
axial member.
[0014] FIGS. 3a and 3b provide a perspective view of an alternate
embodiment of the device packaged within a tube or catheter for
delivery into a fistula.
[0015] FIG. 4 provides a perspective view of a device of the
present invention in a partially deployed state.
[0016] FIG. 5 provides a perspective view of a device of the
present invention in a deployed state.
[0017] FIG. 6 provides a perspective view of another embodiment of
the present invention, further comprising a second portion in the
form of a planar anchoring member.
[0018] FIG. 7 is a perspective view of yet another embodiment of
the present invention, further comprising an additional axial
member in the form of a push rod to aid in redeployment of
device.
[0019] FIG. 8 is a perspective view of a collar and snap lock means
suitable for use in the devices of the present invention for
securing the position of the axial member post deployment.
[0020] FIG. 9 is a perspective view of an alternative locking means
suitable for use in the devices of the present invention wherein a
barbed axial member is employed to provide unidirectional securing
of the axial member post deployment.
[0021] FIG. 10 is a perspective view of a collar suitable for use
in the present invention which incorporates in integral locking
means in the form of individual tangs for securing the axial member
in place.
[0022] FIGS. 11a and 11b are perspective views of a collar formed
from reinforcing elements and a separate elastomeric locking
component which compresses the collar to secure the position of an
axial member passing there through post deployment.
[0023] FIG. 12 depicts a locking clip that may be attached to the
axial member at a predetermined point and upon passing through a
collar, expands to prevent the locking clip and axial member from
sliding back through the collar.
[0024] FIG. 13 is a perspective view of a first portion of a device
subsequent to deployment, wherein the first portion is a disk and
where the device further comprises a reinforcing element in the
form of a strut structure with struts of substantially similar
length.
[0025] FIG. 14a is a side view of a first portion of a device
subsequent to deployment, wherein the first portion is a disk and
where the device further comprises a reinforcing element in the
form of a strut structure located on the disk wherein the struts
are configured such that the portion of the strut located on one
side of the first portion is longer than the portion of the strut
located on the other side of the first portion.
[0026] FIG. 14b is a perspective view of the deployed first portion
of FIG. 14a where in the struts structure is located on one side of
the first portion.
[0027] FIG. 14c is a side view of the deployed first portion of
FIG. 13.
[0028] FIGS. 15a and 15b are perspective views of one embodiment of
the present invention where the first portion is a planar anchoring
member reinforced with a convex strut and collar mechanism.
[0029] FIGS. 16a through 16h depict the typical steps for
deployment of one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The present invention provides medical devices for occlusion
of hollow anatomical structures. It should be understood that
devices of the present invention may be suitable for occlusion of
any hollow anatomical structure such as a perforation, leak, tear,
or aperture within the human body in need of treatment, whether
naturally occurring or as a result of injury, trauma, or disease,
etc. It should be further appreciated that the medical devices of
the present invention may be used to occlude or plug a fistula or
can be used in any other hollow anatomical structures, including
but not limited to veins, arteries, coronary structures, pulmonary
structures, tubular structures associated with reproductive organs,
and the like. In one embodiment in the present invention, the
device is used to treat gastrointestinal (GI) leaks and/or
fistulae.
[0031] In one embodiment, the device of the present invention
comprises a first portion, an axial member which may be oriented
through a fistula space and is connected to the first portion and
at least one occluding member which adjusts upon such axial member
to fill said space. The first portion may seal or close off the end
of the tract of the hollow anatomical structure while the occluding
member is able to effectively fill the tract of the hollow
anatomical structure. This closing and/or sealing and filling of
the void space, or packing of the tissue defect, achieved
concurrently by the devices of the present invention may provide
enhanced healing of the structure, such as a fistula or GI
leak.
[0032] One embodiment of the device of the present invention is
depicted in FIG. 1. As depicted therein, device 1 of the present
invention may comprises a hollow occluding member 2 having a distal
end 3 and proximal end 4, as well as an interior, and an exterior
6. The device may further comprise a first portion 10 with a
central aperture 11 positioned adjacent to the proximal end 4 of
the exterior 6 of the hollow occluding member 2 and connected to
axial member 40. Axial member 40 is attached to the interior distal
end 3 of hollow occluding member 2 and extends through the central
aperture 11 of first portion 10.
[0033] Occluding member 2 may be in the form of a hollow tubular
structure and should be sufficiently flexible, such that it can be
collapsed or bunched up, however, it should have a certain
resilience for holding its place within the hollow tissue structure
or fistula. In many desired uses, a tubular structure is fabricated
of a material that has loft to aid in space filling. Suitable
designs which provide adequate loft and bunching may include but
are not limited to, a web or mesh design, a foam, a sponge, or any
other similar constructs.
[0034] Suitable materials for use in an occluding member of the
present invention include any bioabsorbable material known in the
art and may be synthetic or naturally occurring. Suitable
bioabsorbable polymers for use in the occluding member of the
present invention may include but are not limited to copolymers and
homopolymers of poly (.alpha.-hydroxy esters), such as copolymers
of poly(lactic-co-glycolic acid) (PLGA), poly(glycolic acid) (PGA),
and poly(lactic acid) (PLA); trimethylene carbonate (TMC);
copolymers of PLA and TMC (PLA:TMC), copolymers of PGA and TMC
(PGA:TMC), and copolymers of PLGA and TMC; and combinations
thereof. In one embodiment, the occluding member may be formed of a
self-cohered bioabsorbable web material, such as that described in
U.S. patent application Ser. No. 11/192,858 to Farnsworth et al.,
herein incorporated by reference in its entirety.
[0035] Occluding member 2 may conform to fill voids of varying
sizes or irregular dimensions. Certain aspects of the occluding
member may be altered to modify the extent to which it conforms to
the inside of the hollow anatomical structure. For example, the use
of low density material in construction of the occluding member can
result in an occluding member that expands radially to a greater
extent than a more dense material and more substantially fill a
variety of fistulas or hollow tissue structures. The use of a
highly porous material or structure may enhance cell ingrowth into
the occluding member and promote healing. Similarly, the volume of
material used in occluding member 2 may be varied, to coincide with
the size of the void space to be filled. In addition, the
percentage of the volume of space to be filled may also vary. For
instance, it may be advantageous to fill from about 10% to about
98% of the void volume with the occluding member. Occluding members
that fill a higher percentage of the void volume of the fistula or
hollow anatomical structure have greater contact with the tissue
wall where the occluding member may ultimately serve as a tissue
scaffold. In such instances, the tissue scaffold can provide for
cellular penetration and cell ingrowth. Further, by varying the
geometry of the occluding member along its length, it may be
possible to control the points at which the tissue wall is in
contact with the device or the amount of material that is
positioned within the hollow anatomical structure void or tract.
Alternatively, the cross sectional diameter of the occluding member
may also be varied such that once the occluding member is collapsed
or bunched, the diameter of the deployed device may vary along its
length. Variations in stiffness of the occluding member material
along its length may also lead to the desired variations in
diameter of the deployed device. Such variations in diameter can be
optimized to create predetermined contact regions. Such
predetermined contact regions may advantageously enhance healing of
the fistula, for instance, from the center outward. Any and all of
the above variations in the occluding member may be employed
individually or in combination when selecting an appropriate
occluding member for use.
[0036] Further, when selecting the appropriate materials to be
employed within the present invention, the texture, size of any
fiber diameters where a fibrous material is utilized within the
device, and/or roughness of the external surface of the device or
any portion thereof, and in particular the occluding member, may be
modified to provide debridement of the hollow tissue structure or
fistula where desired. For example, a tighter mesh may provide more
contact with the inner fistula wall. Materials with a more abrasive
quality or enhanced surface roughness can also achieve the desired
debridement. Fillers may be employed within or upon the surface of
the materials of construction to enhance surface roughness of the
device or portions thereof. Fillers that are suitable for this
purpose include but are not limited to inorganic particles, metal
particles, organic particles, and combinations thereof. Inorganic
metal oxides and ceramic particles are of particular interest due
to their biocompatibility and abrasive properties.
[0037] Additionally, the device or any portion thereof may be
coated with, impregnated with, or otherwise incorporate additional
components to enhance cell attachment or promote healing. In one
embodiment, the device may deliver active agents to the hollow
anatomical structure or fistula. Such actives can include but are
not limited to pharmaceutical actives, hormones, growth factors,
cells, and combinations thereof. Those actives of particular
interest may include actives for suppressing or treating infection
such as antibiotics, and actives for the reduction or prevention of
pain or inflammation such as anesthetic agents and
anti-inflammatory agents. Where active agents are incorporated into
the present device, they can be provided as or within a coating on
the device or any portion thereof, they can be directly
incorporated into or admixed in the materials of construction to be
used, they can be sandwiched or between fibers where present, or
otherwise secured to or within the device by any means known in the
art.
[0038] First portion 10 may be fixedly or slidably attached to
axial member 40. First portion 10 may be in the form of a fixed
point, such as a knot or bonded area of material, or any suitable
anchoring member such as a substantially planar anchoring member. A
substantially planar anchoring member may be a disk or sheet of
material. When the first portion is in the form of a substantially
planar anchoring member it should be large enough so that it
overlaps the opening and stiff and/or thick enough to allow it not
to be pulled through the opening. The first portion may comprise
any biocompatible polymer material, whether bioabsorbable or
nonbioabsorbable, naturally occurring or synthetic, or combinations
thereof. In one embodiment, the first portion 10 could comprise any
biocompatible material that is capable of forming a substantially
planar member. Suitable bioabsorbable materials may include but are
not limited to copolymers and homopolymers of poly (.alpha.-hydroxy
esters), such as copolymers of poly(lactic-co-glycolic acid)
(PLGA), poly(glycolic acid) (PGA), and poly(lactic acid) (PLA);
trimethylene carbonate (TMC); copolymers of PLA and TMC (PLA:TMC),
copolymers of PGA and TMC (PGA:TMC) and copolymers of PLGA and TMC;
and combinations thereof. Suitable nonbioabsorbable materials for
use in the first portion 10 may include but are not limited to
nylon, polypropylene, polyethylene, polyethylene terephthalate,
polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene
(ePTFE) and combinations thereof.
[0039] In some embodiments, it may be desirable to seal the
occluding member within the tract of the hollow anatomical
structure, such as a fistula, by sealing both ends of the fistula
tract. This can be done in a variety of ways. The occluding member
itself may be designed such that, upon deployment, the distal end
of the occluding member may form a wide seal at the opposite end of
the fistula. Alternatively, as depicted in FIGS. 6 and 7, the
devices of the present invention may comprise a first portion 10
and a second portion 12 positioned adjacent the distal end and
proximal ends of the occluding member 2 along axial member 40.
Similar to the first portion, the second portion may be in the form
of a fixed point, such as a knot of material, or any suitable
anchoring member, such as a substantially planar anchoring member.
Where the second portion is a substantially planar anchoring
member, a disk or sheet of material may be appropriate. Where a
first and second portion are both employed in the devices of the
present invention, one portion is generally fixedly connected to
the axial member while the other portion is generally slidably or
moveably connected to the axial member. In one embodiment, however,
a second axial member may be employed and one axial member may be
slidably or fixedly attached to both a first and second portion.
The second portion may comprise a bioabsorbable or non
bioabsorbable, natural or synthetic material. Where both a first
portion and a second portion are present, the first and second
portions may comprise the same or different materials. For
instance, the first portion may be bioabsorbable while the second
portion is nonbioabsorbable. This may be advantageous, for example,
when the bioabsorbable portion is positioned outside the hollow
anatomical structure, such as outside the gastrointestinal tract,
and the nonbioabsorbable portion may be located within the hollow
anatomical tissue site, such as within the gastrointestinal tract.
Alternatively, the first portion may be a bioabsorbable material
and the second portion may be a different bioabsorbable material.
Further, it may be advantageous to have a first portion and a
second portion with varying degradation or detachment rates. For
example, where one portion is located within the gastrointestinal
tract, that portion may be designed to detach from the device at a
faster rate than the other portion which may be designed to stay in
place and maintain rigidity longer. Such detachment can be designed
via any suitable means within either the axial member or the first
or second portions.
[0040] As described above, the device also comprises an axial
member 40. As depicted in FIG. 1, the axial member 40 may be
attached to the interior distal end 3 of the hollow occluding
member 2. Alternatively, as depicted in FIG. 4, the axial member 40
may be attached to the first portion 10, with occluding member 2
slidably positioned thereon.
[0041] As shown in FIG. 2, when the axial member 40 is pulled in a
direction away from, in this instance further proximal to, the
first portion 10 and occluding member 2, the distal end 3 of the
occluding member 2 moves toward the proximal end 4 of the occluding
member 2 causing the occluding member 2 to collapse or bunch up.
When the device of the present invention is positioned in a hollow
anatomical structure such as a fistula, the device is positioned so
that the occluding member is inside the fistula tract and the first
portion is at the internal opening of the fistula. Once positioned,
pulling of the axial member results in collapsing or bunching of
the occluding member which plugs the fistula and clamps the tissue
near the first portion, thereby fixing the device in place. Where a
second portion is present, the external opening of the fistula can
likewise be treated. Optionally, this configuration may be used to
effectively seal the fistula tract in situations where sealing
would prove advantageous.
[0042] The axial member may likewise be modified by the addition of
a pull cord 15 as depicted in FIG. 3b. A pull cord can be useful to
lengthen the portion of the device that is available for grasping
by the surgeon while the device is positioned within a catheter 74,
for instance, prior to placement. The pull cord 15 may be attached
to the axial member via any attachment means 44. Attachment means
may include a knot or other tying connection formed from the
material of the pull cord or axial member, a welded connection, an
adhesive bond, a crimping mechanism, etc. Alternatively, the distal
end of the axial member may comprise a self bonded end portion
which may serve as an anchor for a pull cord that can be threaded
through the axial member at a point proximal to the axial member
end portion. In that embodiment, the pull cord itself would not be
immovably fixed to the axial member but could form a sliding loop
that can be cut or opened for easy removal from the device by
pulling.
[0043] Once positioned, axial member 40 or pull cord 15 of the
device may extend from within the fistula to beyond the fistula
tract and into adjacent space. As such, the axial member or pull
cord may act to wick fluids effectively from the fistula space
thereby draining the fistula during the healing process.
Advantageously, where a bioabsorbable axial member or pull cord is
employed, the axial member or pull cord may serve to drain the
fistula during healing and subsequently be resorbed into the body,
eliminating the need for any secondary surgery required for removal
of the device. Although it should be understood that both the axial
member and/or the pull cord can be formed of any bioabsorbable or
nonbioabsorbable, natural or synthetic material.
[0044] In some instances, it may be desirable that the device be
able to be removed and redeployed, for instance in situations where
placement into the fistula or hollow anatomical structure is
initially improper or incorrectly placed. In one embodiment,
affixing an additional axial member to the proximal end of the
device would allow for the occluding member to be axially stretched
if necessary to its original length and repositioned.
Alternatively, as shown in FIG. 7, an additional axial member, such
as a push rod 17 may be provided which is in communication with the
distal end 3 of the occluding member 2 and which could be used to
push the distal end 3 of the occluding device 2 away from the
proximal end 4 after a failed delivery attempt in order to stretch
the occluding member 2 back to its original length, thereby
allowing for redeployment via axial member 40.
[0045] The device of the present invention may further comprise a
guidewire 20 to facilitate positioning of the device in a hollow
anatomical structure. In one embodiment, as depicted in FIGS. 1 and
2, the guidewire 20 is positioned adjacent to axial member 40 and
extends through aperture 11 of first portion 10, continues through
the interior of the occluding member 2, and passes out the distal
end 3 of the occluding member.
[0046] In an alternate embodiment, the device has a lumen running
through it that allows for the passage of a guidewire. This
embodiment allows for maintenance of the guidewire position
throughout the procedure and may provide a degree of self centering
of the device within the fistula tract. Any hole which remains
after the guidewire is removed should be sealed, which can be
accomplished by any suitable means.
[0047] In one embodiment where deployment over a guidewire is
contemplated, the device may be contained within a protective
sleeve or sheath until deployed. In one embodiment, a smooth sheath
outer surface may be desirable to achieve initial placement within
the body and to avoid injury to the surrounding bodily tissues,
however, subsequently, a coarser interface with the fistula tissues
may be desired. One configuration providing this two-fold effect
involves an inner delivery sheath and an outer delivery sheath
whereby the surfaces have coarser and smoother textures,
respectively. Once inserted into the fistula, the outer
smooth-surfaced sheath may be removed, and the coarser-surfaced
inner sheath may be used to enhance contact between the device and
the fistula inner surface through debridement of adjacent tissues.
The inner delivery sheath may also be used to supplement the
collapsing of the occluding member. The roughness of the sheath
surface may be enhanced by any suitable mechanical, chemical, or
material means. In one embodiment, the sheath may be comprised of a
polymer containing abrasive filler particles. Fillers useful for
this purpose include but are not limited to inorganic particles,
metal particles, organic particles, and combinations thereof.
Alternatively, the surface of an otherwise smooth sheath may be
roughened by mechanical means such as mild sand-blasting or
sanding. Once the desired debridement of the fistula tissues is
completed, the inner delivery sheath is removed and final placement
and deployment of the device is commenced.
[0048] Devices of the present invention may further comprise one or
more reinforcement elements 56 that are associated with the first
or second planar anchoring members as depicted in FIG. 4. Said
reinforcement elements may comprise any reinforcement structure or
material that provides support to the first portion and/or second
portion. In one embodiment, the reinforcement elements may take the
form of struts. The reinforcement elements may be attached to or
provide support to the first portion and/or second portion in any
manner. For example, struts may be folded or bent to encompass the
first portion therein or, alternatively, struts may be bonded or
adhered to one surface of the first portion only. When the first
portion and/or second portion are in the form of a planar anchoring
member, the reinforcing elements effectively increase the force
necessary to dislodge the device after deployment. The reinforcing
elements also are useful in preventing the planar anchoring
member(s) from folding onto itself during placement and deployment.
The reinforcing elements may further help reduce migration of the
device within the fistula.
[0049] In one embodiment, where the first and/or second portions
are planar anchoring members, ribs or struts having a rigidity
greater than that of the planar anchoring member(s) may provide
suitable reinforcement. Such ribs or struts may be oriented along
the longitudinal axis of the device when in an undeployed
configuration and subsequently become radially oriented
substantially perpendicular to the longitudinal axis after
deployment. Such ribs or struts may further assist in deployment of
the occluding member.
[0050] In yet another embodiment, the reinforcing elements may be
oriented substantially circumferentially to enhance the optional
seal formed between the first portion and the fistula opening. In
another embodiment the reinforced planar anchoring member is
anatomically shaped upon deployment, by virtue of struts that are
designed to conform to various three dimensional shapes. Such
devices may better conform to a fistula or wound site if the wound
site is located on a portion of the body where the planar end
portions may not seal sufficiently but where sealing is desired.
Combinations and variations of the size or length, number of,
orientation, or configuration of these reinforcing elements may be
used to create a three dimensional form upon deployment of the
device as shown in FIGS. 15a and 15b. In this embodiment,
reinforcing elements in the form of struts 56 are affixed on one
side of a first or second portion and comprise portions of
differing lengths. Upon deployment of the device, struts 56 do not
extend to be substantially linear but rather curve to maintain the
first portion 10 in a generally concave shape.
[0051] Devices of the present invention may further comprise a
collar to assist in controlling movement of the various components
of the devices of the present invention. In one embodiment, the
collar will be integrally formed from the reinforcing elements and
protrude therefrom in a generally perpendicular manner. Collars for
use in the present invention comprise a central aperture that
allows for passage of an axial member and/or pull cord there
through.
[0052] FIG. 14a shows an embodiment of asymmetric reinforcing
elements in which the portion of the reinforcing elements or struts
56 on the collar 30 side is longer than the portion of the strut on
the opposite side. This embodiment is particularly useful to
prevent inversion of the first portion 10, shown in FIG. 14b. FIG.
14c shows an embodiment in which both portions of the reinforcing
elements 56 have approximately equal lengths. Substantially similar
length portions of the reinforcing elements result in the device
having a generally flat cross-section as shown in FIG. 14c.
[0053] Collars suitable for inclusion in the present invention are
intended to reduce the freedom of movement of any components which
may move or slide along the axial member during delivery or
deployment, such as the distal end of the occluding member, and/or
to reduce any movement that may lead to partial or improper
deployment. This function may be accomplished for example by
varying the relative friction between the axial member and the
collar such that as the distal end of the occluding member slides
along the axial member, the friction increases, effectively locking
the distal end of the occluding member in place when fully
deployed. Alternatively, chemical or mechanical locking means may
be employed to achieve the locking of any movable components. For
example, a two part adhesive may be employed which is activated
upon comingling of the first part and second part to secure the
location of the movable components relative to one another.
Alternatively, magnetic means may be employed to secure components
relative to one another. In an alternative embodiment, a snap lock
arrangement may be provided as in FIG. 8 where a locking component
is secured to the axial member at a predetermined location. As the
axial member 40 passes through the collar 30, a tapered locking
component 32 is configured to mate with the collar and snap into
place, thus eliminating further movement of the axial member. In
another example, barbs may be incorporated into the collar and/or
along the axial member in a way that limits movement of the axial
member once deployed. FIG. 9 illustrates one example wherein the
axial member further comprises a barb mechanism. In FIG. 9, the
axial member 40 comprises barbs 42 which can provide for
unidirectional locking of the axial member by engagement with an
optional collar 30. Alternatively, barb-type elements may be
integral to and protrude from the interior portion of an optional
locking collar itself to aid in locking an axial member therein.
FIG. 10 depicts another potential locking mechanism that may be
suitable for use in the present invention, wherein locking collar
31 comprises a plurality of tangs which operate to secure an axial
member therein as it passes through the locking cap preventing
slippage back through the locking collar. FIGS. 11a and 11b depict
yet another embodiment wherein the collar 30 is integrally formed
from the ends of the reinforcing elements or struts 56 and projects
perpendicularly therefrom. A separate elastomeric element 36 can be
introduced to hold collar 30 taught and provide tension on any
axial member passing there through, again preventing slippage of
the axial member once in place. FIG. 12 depicts yet another
optional collar 30 with locking clip 34 which is attached to the
axial member 40 at a predetermined location and designed to pass
through collar 30. Axial member 40 is pulled, via pull cord 15
through the collar 30 during deployment. Once the locking clip has
exited the collar, the clip opens in a butterfly motion or expands
to prevent locking clip 34 and attached axial member 40 from
sliding back through the collar 30. Any other suitable interlocking
means may also be used. Depending on the locking mechanism
selected, the collar may be made from a range of materials
including metals, plastics, elastomers, rubbers, ceramics, or
combinations thereof. Rubber and elastomeric collars may be
designed to provide any desired amount of slippage and/or sliding
along the axial member.
[0054] The present invention also provides methods for occluding a
hollow anatomical tissue structure such as a fistula with these
medical devices. In these methods, the device is positioned in the
hollow anatomical tissue structure so that the occluding member or
the device is positioned inside the hollow anatomical tissue
structure and the first portion is an opening of the hollow tissue
structure. In one embodiment the first portion is a planar
anchoring member, such as a disk, and positioned at the internal
opening of the fistula for tissue to be clamped between the
occluding member and the disk. It should be understood, however,
that the disk may be placed at the internal opening or the external
opening of the hollow anatomical tissue structure. Alternatively
where both first and second portions are employed, a first portion,
such as a planar anchoring member, may be placed at one opening of
the fistula and a second portion, such as a second planar anchoring
member, may be positioned at the opposite opening of the fistula
tract. Means for delivery of the device is selected based upon the
position of the hollow anatomical tissue structure to be occluded
and may be performed in a variety of ways. In one embodiment, the
device is delivered to the site of the hollow anatomical tissue
structure to be occluded endoscopically using, for example, an
endolumenal catheter. Thus, for occlusion of a tracheo-esophageal
fistula, for example, the device is delivered endoscopically via
the trachea or the esophagus.
[0055] By providing a catheter having a roughened outer surface,
debridement of the hollow anatomical structure may be accomplished
via the delivery process. The roughness of the catheter surface may
be enhanced by any suitable mechanical, chemical, or material
means. For example, the outermost portion of the catheter may be
comprised of a polymer containing abrasive filler particles.
Fillers useful for this purpose include but are not limited to
inorganic particles, metal particles, organic particles, and
combinations thereof. Inorganic metal oxide and ceramic particles
are of particular interest due to their biocompatibility and
abrasive properties. Another embodiment may employ mechanical means
to increase the catheter surface roughness, such as but not limited
to mild sand-blasting or sanding.
[0056] Once positioned, the axial member of the device is pulled in
a direction more proximal from the first portion such that the
distal end of the occluding member moves toward the proximal end of
the occluding member, thereby filling the hollow anatomical
structure and clamping tissue of the hollow anatomical structure
near the first portion to lodge the device FIG. 16 shows a series
of images depicting a typical device deployment to plug an
anastomotic dehiscence 62 in a GI tract extraluminal surface
60.
[0057] FIG. 16a shows an extraluminal surface 60 of the GI tract
having an anastomotic dehiscence 62. Initial device deployment
typically begins with the endoscopic placement of guidewire 20 from
within the GI tract through anastomotic dehiscence 62 and extending
beyond extraluminal surface 60 as shown in FIG. 16b. Once the
guidewire 20 is positioned, catheter 74 is fed along guidewire 20
until it passes through anastomotic dehiscence 62 and extends
beyond the tract extraluminal surface (FIG. 16c). Distal end 3 of
the device is then pushed through catheter 74 until sufficient
material to create a plug is present (FIG. 16d). Catheter 74 is
then partially withdrawn leaving sufficient material of occluding
member 2 outside the extraluminal surface 60 (FIG. 16e). On the
inside of the GI tract, endoscope 70 containing partially retracted
catheter 74 is positioned so that first portion 10 has room to
deploy (FIG. 16f). First portion 10 is deployed via a push rod or
inner delivery tube that is positioned within catheter 74 that
extends to the proximal end of endoscope 70. Once freed from
catheter 74, the push rod or inner delivery tube (not shown), may
be used to push first portion 10 against the inner surface of the
GI tract while axial member 40 is pulled via the pull cord from the
proximal end of the endoscope. As the first portion 10 is squeezed
against the inner GI tract surface, struts 56 expand outward,
thereby positioning first portion 10 across anastomotic dehiscence
62 (FIG. 16g). FIG. 16h shows the extraluminal surface 60 with the
collapsed occluding member 2 plugging anastomotic dehiscence
62.
[0058] Because the device of the present invention can be prepared
completely from bioabsorbable materials, the device and methods of
the present invention may provide a non-permanent means for
occluding a hollow anatomical structure such as a fistula. Where
the device is solely constructed of bioabsorbable materials, no
permanent implant or prosthetic material remains in the body and no
additional fixation means are required; the device and methods of
the present invention significantly reduce the chance of infection,
erosion and/or long-term complications. Further, no second
procedure to remove the device, or parts of the device, would be
required.
[0059] In addition, the healing process as well as direction of
healing may be affected by the choice of materials as well as the
design of the device. For example, materials may be used having
differing rates of resorption. When these differing bioabsorbable
materials are used to create a gradient of resorption rates, the
direction of healing and resorption may be controllable. Resorption
of the device could be controlled, for example, by varying the
density of different portions of the device, selecting materials
having different densities for various portions of the device,
varying the fiber diameter for woven or nonwoven materials that may
be incorporated in the device or through a combination of these
variables.
* * * * *