Note: Descriptions are shown in the official language in which they were submitted.
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IMPLANT FOR HERNIA REPAIR
I. FIELD OF THE APPLICATION
The present invention relates generally to the repair of defects in muscular
structures, and more particularly to implants to address ventral wall hernias,
inguinal
hernias, and methods for advancing the implants into a patient less
invasively.
BACKGROUND OF THE INVENTION
The above-referenced patent publication discloses a surgical implant with both
a
tension free and fixation free implant mesh having multiple straps extending
radially
outward from the implant mesh. The straps are pulled through the ventral
(abdominal) wall
musculature to fix the implant mesh to the ventral wall such that when
implanted the
implant mesh is in a slackened condition relative to the ventral wall. The
implant mesh is
sized to be substantially larger than the hernia. To permit tissue ingrowth
from the ventral
wall into the mesh while preventing undesirable ingrowth of structures in the
peritoneal
space such as the bowel into the mesh, the mesh is backed with an anti-
adhesion layer or
substance. A non-adhesion mesh can be used in the pre-peritoneal space.
While the structures in the above-referenced patent publication prove
effective,
present principles understand that the ventral wall (mesh) layer can shrink
over time owing
to tissue ingrowth while the anti-adhesion (peritoneal space) layer does not,
which can lead
to bunching of the implant. Additionally, present principles recognize that
even better
implant compliance to reduce patient discomfort may be provided.
Present principles also address facilitating the centering a large implant,
which is
advanced through a laparoscopic trocar, relative to the hernia defect. This is
challenging
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because the mesh must be rolled in a thick cigar-like fashion to advance it
through a narrow
cannula in a trocar, unrolled, and then properly positioned centrally over the
hernia.
SUMMARY OF THE INVENTION
Among other advantages, the decrease of mesh mass achieved through the implant
design highlighted herewith proves helpful in delivering the implant through a
trocar
cannula.
Accordingly, in one embodiment a hernia repair implant includes a first layer
made
of mesh for facing a body structure having a hernia defect to cover the defect
while
promoting tissue growth into the first layer from the body structure. The
implant also
includes a second layer opposed to the first layer that is made of anti-
adhesion material to
prevent growth of tissue into the second layer from body structures contacting
the second
layer, the second layer being understood to extend radially beyond the first
layer. In
addition, the implant has at least a first elongated centering strap connected
to the first layer
that is connected to the first layer at a first radial location. Also, the
implant includes at
least a first elongated fixation strap connected to the first layer that is
connected to the first
layer at a second radial location that is more distanced from a center of the
first layer than
the first radial location.
If desired, the mesh of the implant may define a pore size. The first layer
may
either be a continuous mesh layer in that it has no openings larger than the
pore size, or it
may be a skeleton mesh layer defining a periphery and defining at least one
opening within
the periphery larger than the pore size. Note that the skeleton portion can be
interrupted
entirely such that islands of mesh can be backed onto the anti-adhesion layer.
Furthermore, in some embodiments the implant also includes a spacer structure
between the first and second layers such that the spacer structure distances
the first and
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second layers. The spacer structure may include at least one rounded nodule
and/or one
sphere. Or, it may establish a spiral shape, or it may include one or more
hollow elements
each defining a complete enclosure. Yet again, the spacer structure may
include plural
popcorn elements, it may be petal-shaped with stems of petals being juxtaposed
adjacent to
each other and ends of petals being radially distant from each other, and/or
the structure may
be established by any combination of the foregoing structures.
In another aspect, a hernia repair implant includes a first layer made of mesh
for
facing a body structure having a hernia defect to cover the defect while
promoting tissue
growth into the first layer from the body structure. The implant also includes
a second
layer opposed to the first layer and made of anti-adhesion material to prevent
growth of
tissue into the second layer from body structures contacting the second layer.
Additionally,
the implant has a structure that is not a flat continuous plane interposed
between the first and
second layers to distance the layers from each other, rendering the combined
structure
dynamic and compressible to stimulate better tissue ingrowth via cyclical
physiologic
loading.
In still another aspect, a method includes advancing, through a trocar, an
implant
into a patient through an incision adjacent to a portion of a muscle wall to
be repaired. The
implant includes centering straps connected to a mesh and fixation straps
connected to the
mesh outboard of where the centering straps are connected. The method also
includes
advancing the centering straps through the muscle wall to partially deploy the
mesh in a
centered positioned relative to a defect in the muscle wall. The method then
includes
advancing the fixation straps through the muscle wall to complete the fixation
of the mesh to
the muscle wall. With the centering straps, no sutures or other tacking
structure is used to
center the mesh over the defect but only the centering straps, which also fix
the mesh to the
wall, are used to center the mesh. This advantageously eliminates a separate
suturing step
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and furthermore permits improved manipulation when centering the mesh compared
to
suturing a central part of the mesh on or near the defect.
In another aspect, a hernia repair implant has a first layer made of mesh for
facing a
body structure having a hernia defect to cover the defect while promoting
tissue growth into
the first layer from the body structure. A second layer is opposed to the
first layer and is
made of anti-adhesion material to prevent growth of tissue into the second
layer from body
structures contacting the second layer. The mesh defines a pore size and the
first layer is a
skeleton mesh layer defining a periphery and defining at least one opening
within the
periphery larger than the pore size.
The details of the present invention, both as to its structure and operation,
can best be
understood in reference to the accompanying drawings, in which like reference
numerals
refer to like parts, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1A is a cross-sectional view of a ventral portion of an anterior
abdominal
wall;
Figure 1B is a cross-sectional view of Figure IA showing a herniation in the
ventral
wall;
Figures 2-5 are schematic diagrams illustrating the implantation of a mesh
with
centering straps;
Figure 6 is a plan view of an example mesh shown in Figures 2-5 suitably
configured
for ventral wall hernia repair, showing four centering straps and seven
fixation straps;
Figure 7 is a plan view of an alternate mesh configured for inguinal canal
hernia
repair;
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Figures 8-11 are plan views of various embodiments of a skeleton mesh that is
flush
against an anti-adhesive layer, with the anti-adhesive layer extending
radially beyond the
skeleton mesh to ensure that tissue in the peritoneal space does not grow
around the edge of
the anti-adhesive layer into the mesh;
Figure 12 is a top perspective view of a skeleton mesh along the lines of
those shown
in Figures 8-11 with centering and fixation straps along the lines of the
embodiment shown
in Figure 6;
Figure 13 is a schematic side view illustrating an implant made of a
relatively
compressible structure interposed between a first mesh layer and an anti-
adhesion side layer
including a second mesh positioned against the compressible structure and an
anti-adhesion
sheet, it being understood that in some embodiments the anti-adhesion sheet
can be omitted
and the second mesh made of anti-adhesion material;
Figure 14 is a top plan view of an example embodiment of an implant mesh
similar
to the one shown in Figure 13 with a spiral-shaped relatively compressible
structure
appearing through a first mesh layer;
Figure 15 is a perspective view of the implant shown in Figure 14;
Figures 16-18 are top perspective views of implants with alternate interior
relatively
compressible structures, with one mesh layer folded away from the other mesh
layer to
better show the configuration of the relatively compressible structures;
Figures 19 and 20 are elevational and perspective views, respectively, of an
"island"
type skeleton mesh with Figure 20 omitting the centering straps for clarity;
and
Figure 21 is a perspective view of a strap retrieval tool.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Initially, it is to be understood that although the repair of ventral hernias
is
particularly referenced herein, the apparatus and methods described herein may
be used for
other surgical or laparoscopic procedures such as, but not limited to, other
instances where a
tissue structure of the human body requires strengthening or supporting.
Furthermore,
although shown in the ventral portion of the abdominal wall and although so
described for
treatment of ventral hernias, the apparatus and methods described herein may
be used for
inguinal hernias, pelvic support, and other procedures and areas of the body.
Now initially referring to Figure 1A, a cross-sectional view of a normal,
anterior
abdominal wall of the ventral region of the body is shown. As shown, the
abdominal wall
includes left and right rectus muscles 10 and 12 enclosed and held in place by
posterior
layers of fascia 14 and anterior layers of fascia 16. These layers of fascia,
which are thin,
strong fibrous tissue, merge together in the region intermediate the rectus
muscles 10 and
12. A thin layer 18, called the peritoneum, covers the posterior side of
the posterior fascia
12. The peritoneum 18 is a soft, pliable layer of tissue material and provides
an enclosure for
the intestines and other internal viscera. A layer of skin composed of the sub
derm is 20 and
dermis 22 covers the exterior of the anterior fascia 16. Figure 1B illustrates
a condition
where a hernia has formed in the wall of the abdomen. The hernial opening is
shown at 24.
In this example, the hernia is formed by the rupture of the fascia layers 14
and 16 in the
region intermediate the rectus muscles 10 and 12. Note that a visceral
protrusion can occur
not only in the midline but also in the lateral aspect of the abdominal wall.
In this case the
viscera protrude across the lateral wall musculature being composed by the
external and
internal oblique and the transverse muscles. In any case, the rupture permits
the internal
viscera to push the peritoneum 18 in an outward direction, creating a bulge 24
in the skin
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layers 20 and 22. If not treated, the condition will only worsen with time,
with the peritoneal
bulge becoming larger.
Now referring to Figures 2-5, schematic diagrams illustrating the implantation
of a
mesh with centering straps are shown. It is to be understood that the figures
below
generally show methods steps in conjunction with devices disclosed herein.
Specifically,
Figures 2-5 show advancing, using a suitable medical instrument, an implant
into a patient
through an incision adjacent to a portion of a muscle wall to be repaired. As
shown and
described below, the implant includes centering straps connected to a mesh and
fixation
straps connected to the mesh outboard of where the centering straps are
connected. In
other words, the centering straps are connected to the mesh closer to the
geometric center of
the mesh than are the fixation straps. The centering straps are thus advanced
through the
muscle wall to partially deploy the mesh in a centered positioned relative to
a defect in the
muscle wall, and the fixation straps are then advanced through the muscle wall
to complete
the fixation of the mesh to the muscle wall.
With the centering straps, no sutures or other tacking structure is used to
center the
mesh over the defect but only the centering straps, which also fix the mesh to
the wall, are
used to center the mesh. This advantageously eliminates a separate suturing
step and
furthermore permits improved manipulation when centering the mesh compared to
suturing
a central part of the mesh on or near the defect since the centering straps
permit the surgeon
to move the mesh laterally as needed to center the mesh by cinching the straps
as necessary
to center the mesh.
Furthermore, note that the meshes described herein, including skeleton mesh
portions of the implants described herein and the mesh straps described
herein, may be
constructed of a solid or a permeable material such that they are receptive to
tissue ingrowth.
Suitable materials for making the meshes may include, but are not limited to,
the following:
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polypropylene mesh such as that distributed by C. R. Bard, Inc. of Murray
Hill, N.J. under
the trade name "Marlex"; a polyethylene mesh material of the type distributed
by E. I. Du
Pont de Nemours and Company of Wilmington, Del, under the trade name
"Alathon"; a
Dacron mesh material or a Nylon mesh material of the type distributed by E. I.
Du Pont de
Nemours and Company of Wilmington, Del.; Teflon; and silicone.
Additionally, the meshes described herein may be constructed from a metallic
mesh
or a polymer mesh having interwoven metallic filaments, if desired. These
filaments may
provide additional strength to the meshes or make the meshes radiopaque for
later
visualization. The meshes may be a single layer or have a multilayer
construction. The
meshes may have one or more layers constructed from a bioabsorbable material
such that
the meshes may be reabsorbed by the body over time.
Now particularly with respect to Figure 2, it may be appreciated that an
implant 26
has been advanced into a patient through, e.g., an incision next to a hernia
30 to be repaired
using a suitable medical device 28 (such as, e.g., a trocar and/or protective
sheath), it being
understood that the implant 26 as shown in Figure 2 is compressed (e.g.,
rolled in a
cigar-style fashion) to allow advantageous advancement using the device 28.
The implant
can thus be advanced into the patient using, e.g., laparoscopic techniques and
toward the
hernia 30 in the ventral wall via the abdominal cavity 32. The hernia 30 has
characteristics
related to/similar to the hernial opening 24 described above. It may be
appreciated from
Figure 2 that the implant 26 can include plural centering straps 34.
If desired, the centering straps 34 may be advanced into the patient first,
with the
remaining portions of the implant delivered via, e.g., the trocar and sheath,
after the straps
34 have been at least partially advanced into the patient having the hernia
30. Advancing
the straps 34 first may make advancement of the straps 34 into the abdominal
wall 38 less
complicated since, e.g., the remaining portions of the implant 26 are less
likely to get in the
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way and obscure a surgeon's view while performing a procedure in accordance
with present
principles and anchoring the centering straps 34 to place the implant 26 at a
desired
orientation.
As may be appreciated from the upward arrows 36 shown in Figure 2, the
centering
straps 34 are advanced at least partially into the abdominal wall 38 and
preferably the
centering straps 36 are advanced completely through the abdominal wall such
that they are
advanced outwardly through the skin of the patient having the hernia 30,
including being
advanced through the sub dermis and dermis. The above-incorporated parent
patent
application of which this is a continuation in part discloses various
techniques for doing this.
Accordingly, it may be appreciated from Figure 3 that the centering straps 34
are at least
partially disposed in the abdominal wall 38 and, owing to being advanced into
the
abdominal wall 38 at a location radially distant from the hernia 30 itself,
the straps 34 at
least partially ensure that no excess mesh or another portion of the implant
26 migrates up
into the hernia 30. Furthermore, the straps 34, when advanced into the
abdominal wall 38,
prevent the implant 26 from sagging when, e.g., pneumoperitoneum is released
and thus it at
least partially eliminates the chances of hernia recurrence and the potential
for seroma. As
may also be appreciated from Figure 3, the device 28 is withdrawn from the
area of the
hernia 30, allowing the implant 26 to begin to expand, unfold, deploy, and/or
otherwise
assume an intended shape to cover the defect in the abdominal wall 38 caused
by the hernia
30 and facilitate tissue growth in accordance with present principles.
Given that Figure 3 shows the implant 26 being fully removed from the device
28, it
may be appreciated that plural fixation straps 40 are also evident on the
implant 26. The
fixation straps 40 will be described further in reference to Figure 5. But
first, note that as
shown in Figure 4, the implant 26 is shown at least partially
covering/blocking/obscuring
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the hernia 30 in the abdominal wall 38, it being understood that the implant
26 shown in the
configuration of Figure 4 has at least partially assumed its intended shape.
Now in reference to Figure 5, it may be appreciated that the fixation straps
40 have
now been advanced at least partially into the abdominal wall 38. If desired,
the fixation
straps 40 may be advanced completely through the abdominal wall 38 such that
they are
advanced through the skin of the patient with the hernia 30. It may be further
appreciated
from Figure 5 that a parietal surface of the implant 26 is now disposed
against the abdominal
wall 38 to fully cover the hernia 30, thereby facilitating tissue growth in
accordance with the
principles set forth herein, while also advantageously blocking passage of
objects, fluid,
organs, tissue, etc. from passing through the hernia 30 at least partially due
to the visceral
surface of the implant 26 (which may have anti-adhesion characteristics as set
forth herein).
Note that either or both of the centering straps 34 and fixation straps 40 may
be
secured into abdominal wall 38 by way of friction between the straps 34 and 40
and the wall
38 to minimize patient discomfort while still ensuring that the implant 26
remains in its
intended position/orientation, and also does not migrate within the abdominal
cavity 32.
This provides a relatively tension-free anchoring means while also obviating
the need to use
other tacking methods that may otherwise provide potential points of adhesion
and/or
tension during the healing process of the patient, which is undesirable due
to, e.g., patient
discomfort. Eliminating sutures or other tacking devices also enables the
implant to move
with expansion or contraction of the surrounding tissue as part of the healing
process due to
tissue changes over time as the wall 38 heals and as incorporation tissue
invades the implant
26. In essence, securing the implant using only strap friction better
accommodates tissue
movement and/or expansion. However, if deemed necessary additional forms of
fixation
may nonetheless be used, such as, but not limited to, tacking, sutures,
fasteners, and clamps.
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Notwithstanding the foregoing, it may be appreciated that using only the
friction
means of abdominal wall attachment provides a relatively tension-free
condition in which
the implant 26 is secured into its position with sufficient slack so that as
surrounding tissue
expands or moves, the implant slack helps avoid pulling and possible tearing
of surrounding
tissue that may otherwise result from an implant that is secured too tightly
or does not have
any residual slack due to, e.g., tacking or clamps. Accordingly, it may be
appreciated that
by virtue of the friction created between the abdominal wall 38 and straps 34
and 40, the
straps 34 and 40 secure and stabilize the implant 26 while also permitting a
desired level of
movement the straps 34 and 40 relative to surrounding tissues over time. The
relatively
tension-free straps 34 and 40, as well as the configuration of the implant 26
that completely
covers the hernia 30, provides for substantial slack allowing for long-term
natural
abdominal wall remodeling which present principles recognize as being
particularly
important to reducing and fixing hernias. It is to be understood that this
type of tension free
and fixation free implant may promote better healing, reduce premature tear-
out or
dislodgement or dislocation and provide increased comfort and acceptance by
the patient.
Still addressing the straps 34 and 40, note that while Figures 2-5 show that
the straps
34 and 40 are shown attached to the implant 26 when advanced into the patient
having the
hernia 30, in other embodiments the implant 26 may be advanced into the
abdominal cavity
32 with the straps 34 and 40 unattached thereto. Thus, the straps 34 and 40
may be
advanced at least partially into the abdominal wall 38 while unattached from
the implant 26
and then subsequently be coupled/attached to the implant 26. Alternatively or
in any
desired combination, the implant 26 may be advanced into the abdominal cavity
32 with the
straps 34 and 40 unattached, and then subsequently the straps may be attached
to the implant
26 prior to the straps 34 and 40 being advanced into the abdominal wall 38. It
may be
appreciated that advantages of advancing the implant 26 into the abdominal
cavity 32 with
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the straps 34 and 40 unattached may be desired for reasons such as, but not
limited to, ease
of advancement of the implant 26 into the patient (e.g., if the implant is
relatively large and
difficult to place into or maneuver using the device 28) and ease of placement
of the implant
26 against the abdominal wall 28 to thereby cover the hernia 30.
Continuing in reference to the straps 34 and 40, the straps may be made of a
mesh
such as a polypropylene mesh that facilitates tissue growth in accordance with
present
principles. The straps 34 and 40 may be made of any other suitable synthetic
materials,
biological materials, or combination of materials, if desired. Regardless, it
is to be
understood that to further facilitate advancement of the straps 34 and 40 at
least partially
into the abdominal wall 38, the straps 34 and 40 may include surgical needles
(not shown in
Figures 2-5) engaged with respective ends of the straps to facilitate
advancement of the
straps 34 and 40 into the abdominal wall 38. In some embodiments, the needles
are
removably engaged with the straps 34 and 40 such that the needles may be
disengaged with
straps 34 and 40 after the straps 34 and 40 have been at least partially
advanced into the
abdominal wall.
Also note that in some embodiments, the straps 34 and 40 may be tapered at the
ends
to be advanced into the abdominal wall. This may facilitate advancement of the
straps 34
and 40 through various tissue structures. Accordingly, the reduced lateral
profile may
reduce friction and the resultant force required to, e.g., pull or push the
straps 34 and 40 into
the abdominal wall 38. Note that the straps 34 and 40 may be made out of
polyethylene,
polypropylene, Teflon, nylon, silicone or other suitable polymer in accordance
with present
principles that may be useful to reduce friction as the straps 34 and 40 pass
through tissue in
the abdominal wall 38.
Now addressing Figure 6, a plan view of an example mesh implant such as the
one
shown in Figures 2-5 suitably configured for ventral wall hernia repair is
shown. Figure 6
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shows, for non-limiting illustration, four centering straps 44 and seven
fixation straps 46
attached to the mesh implant 42. It is to be understood that the centering
straps 44 may be
substantially similar in function and configuration to the centering straps 34
described
above, while the fixation straps 46 in Figure 6 may be substantially similar
in function and
configuration to the fixation straps 40 described earlier. Note that while
Figure 6 shows
four straps 44 and seven straps 46, more or fewer straps may be used as
desired.
Further, it may be appreciated from Figure 6 that the body 48 of the implant
42 may
be generally circular/radial in shape, though any desired shape may be used to
sufficiently
cover a hernial opening. Still, it is noted that in Figure 6 which shows the
generally
circular/radial implant 42, the centering straps 44 are attached to the
implant 42 at radial
locations that are less distanced from the center of the implant than where
the fixation straps
46 are attached to the implant 42.
Moving on, Figure 7 shows a plan view of an alternate mesh implant configured
for
hernia repair. The body 54 of the implant 50 shown in Figure 7 is generally
rectangular in
shape, again noting that in other embodiments the implants described herein
may be in any
suitable geometric or non-geometric shape (e.g., a shape specifically tailored
and/or formed
by a physician) for covering a hernia opening. Figure 7 also shows four
fixation straps 52
extending diagonally away from respective corners of the body 54. It is to be
understood
that the straps 52 may be substantially similar in function and configuration
to the straps 40
described above, with some differences being considered given the differing
shapes of the
bodies of the respective implants to which the straps are attached. Moreover,
though not
shown in Figure 7, if desired centering straps may also be included on the
body 54 of the
implant 50 in accordance with present principles, it being understood that the
centering
straps, if included, would be attached to the body 54 at areas of the body 54
relatively closer
to the center of the body 54 than where the straps 52 are attached. Also note
that the straps
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54 as well as other centering and fixation straps disclosed herein may be, in
examples, two
centimeters in width and ten centimeters in length in non-limiting
embodiments. In
addition, note that the body 54 may be, but is not limited to, the dimensions
of fifteen
centimeters by fifteen centimeters, as well as other implant bodies disclosed
herein.
However, note that the size and length of one or more elements included on the
implants
described herein may vary depending on the dimensions of the hernia to be
repaired.
Attention is now made to Figures 8-11, which are plan views of various
embodiments of a skeleton mesh that is flush against an anti-adhesive layer,
with the
anti-adhesive layer in some examples extending radially beyond the skeleton
mesh (for
example, by a few centimeters) to ensure that tissue in the peritoneal space
does not contact
or become adhered around the edge of the anti-adhesive layer and into the
mesh.
Advantageously the skeleton mesh has less mass than a continuous mesh,
facilitating
advancement of the mesh through the trocar. Moreover, because the skeleton
mesh offers
sufficient yet not excessive room for tissue ingrowth, it is less likely to
bunch when tissue
grows into it but not into the anti-adhesion layer, as can happen when a
completely
continuous ingrowth mesh is joined to an anti-adhesion layer.
Additionally, the gaps or islands established by the example skeleton
structures
described below ensure that scar tissue cannot bridge and thus an undesirable
full length
contraction of the mesh during healing is avoided. Radial contraction of the
mesh caused
by such scar tissue growing into the mesh contracts the individual "islands"
or mesh
portions of the skeleton structure but cannot transmit contraction across the
entire length of
the anti-adhesion layer. In the embodiments of Figures 8-12, a circumferential
ring of
mesh is shown (which may also be an interrupted ring) inboard of the edge of
the
anti-adhesion layer. This outer ring provides an ingrowth ring that prevents
lifting of the
implant and possible entrapment of viscera behind the implant.
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Referring first to Figure 8, an exemplary implant 56 has a skeleton layer 58
made of
mesh for facing a body structure having a hernia defect to cover the defect
while promoting
tissue growth into the skeleton layer from the body structure. The skeleton
mesh 58 can be
made of any suitable tissue in-growth material such as any of the material
described above.
The implant 56 also has a second layer 60 that is opposed to the skeleton
layer 58. It is to
be understood that the second layer 60 is made of anti-adhesion material to
prevent growth
and/or incorporation of unintended tissue from the abdominal cavity contacting
the second
layer into the implant 56.
As but one example, the portion of the implant 56 having the skeleton layer 58
may
be juxtaposed alongside and/or against an abdominal wall to cover a hernial
opening in the
abdominal wall such that the second layer 60 faces the abdominal cavity of the
patient.
Thus, organs such as the patient's bowels will be prevented from sticking to,
growing on,
being entangled with, etc., the implant 56 by virtue of the anti-adhesion
characteristics of
the second layer 60 blocking any contact between the organs and the skeleton
layer 58.
It may therefore be appreciated that the anti-adhesion elements and materials
described herein prohibit ingrowth or attachment of tissue to portions of the
implant having
the anti-adhesion elements and/or properties. In addition to the second layer
60 having
anti-adhesion characteristics, note that in lieu of or in addition to the
implant having a
second layer such as the layer 60 with anti-adhesion characteristics, other
portions of the
implants described herein may be coated with an anti-adhesional coating as
desired (e.g., on
a side to facing away from the abdominal wall and toward the abdominal cavity)
to thereby
inhibit tissue attachment. Put another way, it may be appreciated that the
anti-adhesional
characteristics may be particularly useful for those implant surfaces that are
exposed to the
internal viscera of the abdominal cavity. One example of an adhesion resistant
material is a
thread of polytetrafluoroethylene polymer material of the type sold under the
trade name
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"Gore-Tex" by W. L. Gore & Associates, Inc. Other non-limiting examples
include single
sheet polypropylene such as Dipromed, PVDA films, silicone barriers, or
biologic or
biomimetic meshes.
With reference still being made to Figure 8, it may be appreciated that the
example
mesh skeleton layer 58 has a generally oval portion 62 and an "X" patterned
portion 64
inside the oval portion 62 extending diagonally relative to the major and
minor axes of the
oval portion 62 to respective inside edges of the oval portion 62. It may be
further
appreciated from Figure 8 (as well as from the respective implant structures
of Figures 9-12)
that the second (anti-adhesion) layer 60 extends radially beyond the skeleton
layer 58.
Although the "X" portion 64 includes two continuous strips crossing each
other, the strips
need not be continuous, and instead "islands" of mesh that are not connected
to each other
can establish the skeleton, tissue ingrowth layer.
Figure 9 shows an alternate skeletal structure for a layer of an implant to be
positioned against the abdominal wall of a patient in accordance with present
principles.
The implant 66 shown in Figure 9 has a skeleton layer 68 made of mesh for
facing a body
structure having a hernia defect. The implant 66 also has a second layer 70
that is opposed
to the skeleton layer 68. It is to be understood that the second layer 70 is
made of
anti-adhesion material to prevent growth of tissue in accordance with present
principles.
Note that Figure 9 shows the mesh skeleton layer 68 being comprised of a
generally
oval portion 72 and cross-pattern or plus-sign-pattern portion 74 inside the
oval portion 72
with mesh extending in vertical and horizontal directions relative to the
major and minor
axes of the oval portion 72 to respective inside edges of the oval portion 72.
Also note that
the second layer 70 extends radially beyond the skeleton layer 68.
Figure 10 shows another alternate skeletal structure for a layer of an implant
to be
positioned against the abdominal wall of a patient in accordance with present
principles.
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The implant 76 shown in Figure 10 has a skeleton layer 78 made of mesh for
facing a body
structure having a hernia defect. The implant 76 also has a second layer 80
that is opposed
to the skeleton layer 78. It is to be understood that the second layer 80 is
made of
anti-adhesion material to prevent growth of tissue in accordance with present
principles.
Note that Figure 10 shows the skeleton layer 78 made of a mesh with a
generally
oval portion 82 and a pattern inside the oval portion 82 having a central
horizontal portion
84 and four diagonal portions 86 extending diagonally away from the two
respective ends of
the central horizontal portion 84. Note that the description of the internal
pattern of the
skeleton layer 78 is made relative to the major and minor axes of the oval
portion 82 of the
skeleton layer 78. Also note that the second layer 80 extends radially beyond
the skeleton
layer 78.
Figure 11 shows yet another alternate skeletal structure for a layer of an
implant to
be positioned against the abdominal wall of a patient in accordance with
present principles.
The implant 88 shown in Figure 11 has a skeleton layer 90 made of mesh for
facing a body
structure having a hernia defect. The implant 88 also has a second layer 92
that is opposed
to the skeleton layer 90. It is to be understood that the second layer 92 is
made of
anti-adhesion material to prevent growth of tissue in accordance with present
principles.
Note that Figure 11 shows the skeleton layer 90 with a generally oval portion
94 and
mesh horizontal portion 96 inside the oval portion 94 that extends along the
major axis of
the oval portion 94 and tenninates at inside edges of the oval portion 94.
Also note that the
second layer 92 extends radially beyond the skeleton layer 90.
Reference is now made to Figure 12. Figure 12 shows a top perspective view of
a
hernia implant 98 with a skeleton mesh 100 along the lines of those shown in
Figures 8-11
with elongated centering straps 102 and elongated fixation straps 104 along
the lines of the
embodiment shown in Figure 6. Figure 12 thus shows the skeleton mesh 100 with
a
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second, anti-adhesion layer 106 extending radially beyond the skeleton mesh
100. It may
be appreciated that the skeleton mesh 100 is substantially similar in
configuration to the
skeleton layer 78 described in reference to Figure 10, though it is to be
understood that any
of the other skeleton layer configurations described herein may be used in
accordance with
present principles.
Still in reference to Figure 12, it is to be appreciated that the elongated
centering
straps 102 are connected to the skeleton mesh 100. In some embodiments the
straps 102
may extend radially beyond the periphery of the skeleton mesh 100, but in
other
embodiments the straps 102 need not necessarily extend radially beyond the
periphery of
the skeleton mesh 100 so long as they are long enough to be advanced at least
partially into
the abdominal wall of a patient as desired. Regardless, note that the
centering straps 102
are connected to the skeleton mesh 100 at a first radial location of the
skeleton mesh 100
relative to the center of the skeleton mesh 100, a second location to be
described shortly.
It may also be appreciated from Figure 12 that the elongated fixation straps
104 are
connected to the skeleton mesh 100 inboard of the anti-adhesion layer edges.
Because the
straps are passed through the abdominal wall directly in line with their
attachment point to
the skeletal mesh, the overlap of the anti-adhesion layer prevents contact of
viscera to
exposed strap material. In some embodiments the straps 104 may extend radially
beyond a
periphery of the skeleton mesh 100, but in other embodiments the straps 104
need not
necessarily extend radially beyond the periphery of the skeleton mesh 100 but
are
nonetheless long enough to be advanced at least partially into the abdominal
wall of a
patient as desired. Regardless, note that the fixation straps 104 are
connected to the
skeleton mesh 100 at a second radial location of the skeleton mesh 100 that is
more
distanced from a center of the skeleton mesh 100 than the first radial
location described in
the paragraph above.
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Referring specifically to the skeleton mesh 100, note that the skeleton mesh
100
defines a pore size and at least one opening within the periphery that is
larger than the pore
size (e.g., as may be appreciated from the skeleton configurations of Figures
8-11).
Furthermore, the skeleton mesh 100 along the lines of the skeleton layers of
Figures 8-11 is
understood to mesh be made of polypropylene in exemplary embodiments, but may
be made
from other suitable synthetic materials, a biological materials, or
combination of materials
such as those described herein.
Moving on, reference is now made to Figure 13, which is a schematic side view
illustrating an implant 108 made of a compressible, preferably plastic
structure 116
interposed between a first mesh layer 110 and a second mesh layer 112 flush
against the
second mesh layer 112. An anti-adhesion side layer 114 in accordance with
present
principles is also shown. However, it is to be understood that in some
embodiments the
anti-adhesion sheet 114 can be omitted and the second mesh 112 can be made of
and/or at
least partially coated with an anti-adhesion material.
Furthermore, it may be appreciated from Figure 13 that the structure 116 is
not a flat
continuous plane interposed between the first mesh 110 and second mesh 112,
and may in
some embodiments act as a force/shock absorber providing resilience around the
implant
108 and hernial area. Thus, the structure 116 distances the mesh 110 and mesh
112 from
each other to facilitate tissue ingrowth into the implant. In the exemplary
embodiment
shown in Figure 13, the structure 116 includes plural rounded nodules with
vacant spaces in
between nodules and with flat portions opposite the rounded ends of the
nodules to thereby
structurally connect the nodules, in other words, a corrugated-like structure.
It is to be
understood that in other embodiments other configurations may be used, such as
plural
spheres at least comprising the compressible structure to be interposed
between the two
meshes 110 and 112. Ribs made from mesh may also be used.
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Turning now to Figure 14, atop plan view of an example embodiment of an
implant
mesh 118 similar to the one shown in Figure 13 except with a spiral-shaped
compressible
structure 120 (rather than rounded nodules) appearing through a first mesh
layer 122 in
accordance with present principles is shown. The spiral shape of the structure
120 may
also be appreciated from the perspective view of the implant 118 shown in
Figure 15.
Reference is now made to Figures 16-18, which are top perspective views of
implants in accordance with present principles having alternate compressible
structures.
Note that Figures 16-18 show one mesh layer folded away from the other mesh
layer to
better show the configuration of the respective structures of the figures.
Describing Figure 16, it may be appreciated that an implant 124 includes a
first mesh
layer 126 and a second mesh layer 128. Figure 16 also shows a structure 129,
which
includes plural hollow elements each defining a complete enclosure. If
desired, the hollow
elements of the structure 129 may be ring-like ancUor cylindrical with an
inner generally
circular core supporting at least one generally circular mesh wing extending
outward
therefrom.
Describing Figure 17, it may be appreciated that an implant 130 includes a
first mesh
layer 132 and a second mesh layer 134. Figure 17 also shows a compressible
structure 136,
which is comprised of plural popcorn elements, which may have differing
"popcorn"
configurations as shown. For example, the popcorn configurations may
essentially
resemble abstract origami shapes, may resemble the shapes and variances of
popcorn, may
be comprised of various overlapping circular strips to comprise ball-like
shapes, etc.
Describing Figure 18, it may be appreciated that an implant 138 includes a
first mesh
layer 140 and a second mesh layer 142. Figure 18 also shows a compressible
structure 144,
which is petal-shaped and includes sterns of petals 146 that are juxtaposed
adjacent to each
other, as well as ends of petals 148 that are radially distant from the center
of the implant
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138.
Figures 19 and 20 show a skeleton-style mesh 200 including an anti-adhesion
layer
202 supporting an island-style skeleton mesh 204 composed of islands of tissue
ingrowth
mesh that do not touch each other except by being disposed on a common anti-
adhesion
layer, i.e., at least some of the tissue ingrowth-promoting islands are not
connected to
another tissue ingrowth-promoting island by tissue ingrowth-promoting
structure, although
all portions of the mesh 204 may be supported on the anti-adhesion layer 202.
Note that the
islands in Figure 20 are formed in an outer interrupted ring and three inner
interrupted lines
of somewhat elongated islands. Fixation straps 206 rise from islands in the
outer ring;
centering straps may also be used, connected to some of the inner islands, in
accordance
with description above.
Figure 21 shows an example strap retrieval tool 300 with an elongated rigid
plastic
handle 302 and a thumb indent 304 configured for receiving a surgeon's thumb
for gripping
purposes. An elongated curved almost semi-circular metal retriever 306 extends
distally
away from the handle 302 as shown, terminating in a slit or eye 308 through
which one of
the centering or fixation straps discussed above can be passed to thereby
engage the
retriever 306 with the strap. When open surgery is used the retriever 306 is
advanced into
the patient through subcutaneous tissue and muscle layers into the peritoneum,
whereas in
laparoscopic surgery the retriever 306 is advanced into the patient
transcutaneously. The
surgeon engages the strap with the eye 308 and pulls the tool 300 with strap
back through
various tissue shown in Figure 19 to extend outside the patient as shown. The
straps can
then be trimmed and the tissue tented outwardly so the straps slide back into
the tissue,
remaining in contact with the tissue for fixation purposes through friction.
It may now be appreciated based on all of the foregoing the implants described
herein may be made relatively oversized compared to the size of the hernia.
Any such
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relatively larger implant may improve its adhesion to the abdominal wall. An
implant
sized larger than the hernia may in some embodiments be 1.5 times larger than
the area of
the hernia, or may be two times larger than the area of the hernia.
It may also be appreciated that the anti-adhesion portions of the implants
described
herein may extend radially past the polypropylene mesh elements facilitating
tissue growth
such that, e.g., organs are not at risk of contacting the mesh elements.
Moreover, the
implants may be trimmable such that they may be trimmed while in the abdominal
cavity
once the implant is advanced into the patient but before the implant is placed
at a desired
location against the abdominal wall. The composition of the implant, at least
a portion
being made out of, e.g., polypropylene, allows for such trimming. Trimming may
be
advantageous to shape an implant in accordance with present principles to
uniquely
conform to and/or uniquely cover a hernia.
While the particular IMPLANT FOR HERNIA REPAIR is herein shown and
described in detail, it is to be understood that the subject matter which is
encompassed by
the present invention is limited only by the claims.
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