U.S. patent application number 10/961581 was filed with the patent office on 2005-04-14 for biopsy cavity marking device and method.
Invention is credited to Fawzi, Natalie V., Lebovic, Gail, Sirimanne, D. Laksen, Sutton, Douglas S..
Application Number | 20050080338 10/961581 |
Document ID | / |
Family ID | 26915025 |
Filed Date | 2005-04-14 |
United States Patent
Application |
20050080338 |
Kind Code |
A1 |
Sirimanne, D. Laksen ; et
al. |
April 14, 2005 |
Biopsy cavity marking device and method
Abstract
These are breast implant devices and methods of use. The breast
implants are made of a matrix of collagen material having a porous
structure for supporting surrounding tissue of a breast. The
implants are also configured to provide a framework for the
in-growth of fibrous tissue into the matrix. The matrix can be
resilient and/or self-expanding. The methods of use include the
steps of forming a cavity having surrounding breast tissue and
forming a resorbable implant made up of collagen that is sized to
occupy the cavity. The implant is then implanted into the cavity,
thereby supporting the surrounding tissue and allowing for
in-growth of fibrous tissue into and replacing the resorbable
material. The resorbable material may also be elastically
compressible, such that the step of implanting includes the step of
compressing the resorbable material. The implants may also contain
a medicinal, therapeutic, or diagnostic substance.
Inventors: |
Sirimanne, D. Laksen; (Palo
Alto, CA) ; Sutton, Douglas S.; (Pacifica, CA)
; Fawzi, Natalie V.; (Belmont, CA) ; Lebovic,
Gail; (Menlo Park, CA) |
Correspondence
Address: |
O'MELVENY & MEYERS
114 PACIFICA, SUITE 100
IRVINE
CA
92618
US
|
Family ID: |
26915025 |
Appl. No.: |
10/961581 |
Filed: |
October 8, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10961581 |
Oct 8, 2004 |
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10114712 |
Apr 1, 2002 |
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10114712 |
Apr 1, 2002 |
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09805652 |
Mar 13, 2001 |
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09805652 |
Mar 13, 2001 |
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09285329 |
Apr 2, 1999 |
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6356782 |
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09285329 |
Apr 2, 1999 |
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09220618 |
Dec 24, 1998 |
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Current U.S.
Class: |
600/431 ;
424/423; 623/8 |
Current CPC
Class: |
A61B 90/39 20160201;
A61K 49/006 20130101; A61B 2090/3987 20160201; A61B 2090/3908
20160201; A61K 49/222 20130101; A61B 8/481 20130101 |
Class at
Publication: |
600/431 ;
623/008; 424/423 |
International
Class: |
A61F 002/00; A61B
006/00 |
Claims
What is claimed is:
1. A breast implant comprising a matrix of collagen material, the
matrix having a porous structure for supporting surrounding tissue
of a breast and configured to provide a framework for the in-growth
of fibrous tissue into the matrix.
2. The breast implant of claim 1, wherein the matrix comprises a
foam.
3. The breast implant of claim 1, wherein the matrix comprises a
resilient framework for implantation by compressing the matrix into
a smaller volume, the matrix expanding resiliently within the
breast.
4. The breast implant of claim 1, wherein the matrix is
self-expanding.
5. A method for replacing excised human breast tissue with an
implant comprising the steps of: forming a cavity having
surrounding tissue within a breast; forming the implant entirely of
resorbable material comprising collagen and sizing the implant to
occupy the cavity; and implanting the implant in the cavity, the
implant supporting the surrounding tissue and allowing for
in-growth of fibrous tissue into and replacing the resorbable
material, wherein the resorbable material is elastically
compressible, and the step of implanting includes the step of
compressing the resorbable material.
6. The method of claim 5, further comprising the step of
introducing into the implant at least one of a medicinal,
therapeutic or diagnostic substance.
7. The method of claim 6, wherein the at least one substance is
selected from the group consisting of radiation material,
chemotherapies, cancer therapies, hemostatic material, and
radiographic markers.
8. The method of claim 5, wherein the step of implanting the
implant in the cavity comprises expanding the implant within the
cavity.
9. A method for replacing excised human breast tissue with an
implant comprising the steps of: forming a cavity having
surrounding tissue within a breast; forming the implant entirely of
resorbable material comprising collagen; and implanting the implant
in the cavity, the implant supporting the surrounding tissue and
allowing for in-growth of fibrous tissue into and replacing the
resorbable material, wherein the resorbable material is elastically
compressible, and the step of implanting includes the step of
compressing the resorbable material.
10. The method of claim 9, further comprising the step of
introducing into the implant at least one of a medicinal,
therapeutic or diagnostic substance.
11. The method of claim 10, wherein the at least one substance is
selected from the group consisting of radiation material,
chemotherapies, cancer therapies, hemostatic material, and
radiographic markers.
12. The method of claim 9, wherein the step of implanting the
implant in the cavity comprises expanding the implant within the
cavity.
13. A method for replacing excised human breast tissue with an
implant comprising the steps of: forming a cavity having
surrounding tissue within a breast; forming an implant entirely of
resorbable material and sizing the implant to occupy the cavity;
and implanting the implant in the cavity, the implant supporting
the surrounding tissue and allowing for in-growth of fibrous tissue
into and replacing the resorbable material, wherein the resorbable
material is formed from a self-expanding foam and the step of
implanting is performed by injection of the self-expanding
foam.
14. The method of claim 13, further comprising the step of
introducing into the implant at least one of a medicinal,
therapeutic or diagnostic substance.
15. The method of claim 14, wherein the at least one substance is
selected from the group consisting of radiation material,
chemotherapies, cancer therapies, hemostatic material, and
radiographic markers.
Description
[0001] This is a continuation of U.S. application Ser. No.
10/114,712, filed Apr. 1, 2002, which is a continuation of U.S.
application Ser. No. 09/805,652, filed March 13, 2001, which is a
continuation of U.S. application Ser. No. 09/285,329, filed Apr. 2,
1999, now U.S. Pat. No. 6,356,782, which is a continuation-in-part
of U.S. application Ser. No. 09/220,618, filed Dec. 24, 1998, now
abandoned. All of the above patents and applications are
incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] This invention is directed to subcutaneous cavity marking
devices and methods. More particularly, a cavity marking device and
method is disclosed that enable one to determine the location,
orientation, and periphery of the cavity by radiographic,
mammographic, echographic, or other non-invasive techniques. The
invention typically is made up of one or more resilient bodies and
a radiopaque or echogenic marker.
BACKGROUND OF THE INVENTION
[0003] Over 1.1 million breast biopsies are performed each year in
the United States alone. Of these, about 80% of the lesions excised
during biopsy are found to be benign while about 20% of these
lesions are malignant.
[0004] In the field of breast cancer, stereotactically guided and
percutaneous biopsy procedures have increased in frequency as well
as in accuracy as modern imaging techniques allow the physician to
locate lesions with ever-increasing precision. However, for any
given biopsy procedure, a subsequent examination of the biopsy site
is very often desirable. There is an important need to determine
the location, most notably the center, as well as the orientation
and periphery (margins) of the subcutaneous cavity from which the
lesion is removed.
[0005] In those cases where the lesion is found to be benign, for
example, a follow-up examination of the biopsy site is often
performed to ensure the absence of any suspect tissue and the
proper healing of the cavity from which the tissue was removed.
This is also the case where the lesion is found to be malignant and
the physician is confident that all suspect tissue was removed and
the tissue in the region of the perimeter or margins of the cavity
is "clean."
[0006] In some cases, however, the physician may be concerned that
the initial biopsy failed to remove a sufficient amount of the
lesion. Such a lesion is colloquially referred to as a "dirty
lesion" or "dirty margin" and requires follow-up observation of any
suspect tissue growth in the surrounding marginal area of the
initial biopsy site. Thus, a re-excision of the original biopsy
site must often be performed. In such a case, the perimeter of the
cavity must be identified since the cavity may contain cancerous
cells. Identification of the cavity perimeter necessary to avoid
the risk of opening the cavity, which could release and spread
cancerous cells. Moreover, the site of the re-excised procedure
itself requires follow-up examination, providing further impetus
for accurate identification of the location of the re-excised site.
Therefore, a new marker will be placed after re-excision.
[0007] Prior methods of marking biopsy cavities utilize one or more
tissue marking clips as the biopsy site marking device. Most
commonly, these marker clips have a "horseshoe" configuration. The
marker clips attach to the walls of the cavity when the free ends
or limbs of the "horseshoe" are pinched together, trapping the
tissue. This device has significant drawbacks.
[0008] For instance, prior to placing the marker clip at the cavity
site, the site must be thoroughly cleaned, typically by vacuum, to
remove any residual tissue debris. This minimizes the possibility
that the marker clip attaches to any loose tissue as opposed to the
cavity wall. Once the cavity is prepared, the clip must be examined
to ensure that the limbs of the clip are substantially straight. If
the limbs have been prematurely bent together, the clip will be
discarded since it will most likely not attach properly to the
cavity wall. Actual placement of the clip often requires additional
vacuum of the cavity wall to draw the wall into the aperture
between the limbs of the marking clip so that a better grip is
obtained between the limbs of the clip. Additionally, there is
always the possibility that the clip may detach from the cavity
wall during or after withdrawal of the tools used to place the clip
into the cavity.
[0009] Aside from the problems inherent in the placement of the
marking clip, there are also limitations associated with how well
the marking clip can identify a biopsy cavity. As the marking clip
must trap tissue for proper attachment, in cases of endoscopic
placement, the clip can only be placed on a wall of the cavity
substantially opposite to the opening of the cavity.
[0010] Moreover, patient concern limits the number of clips that
may be placed in a cavity. As a result, the medical practitioner is
forced to identify the outline of a three dimensional cavity by a
single point as defined by the marking clip. Obviously,
determination of the periphery of a biopsy cavity from one point of
the periphery is not possible.
[0011] These limitations are compounded as the biopsy cavity fills
within a few hours with bodily fluids, which eventually renders the
cavity invisible to non-invasive techniques. Another difficulty in
viewing the clip stems from the fact that the clip is attached to
the side, not the center, of the cavity. This makes determining the
spatial orientation and position of the cavity difficult if not
impossible during follow-up examination. Additionally, during a
stereotactic breast biopsy procedure, the breast is under
compression when the marking clip is placed. Upon release of the
compressive force, determining the location of the clip can be
unpredictable, and the orientation as well as the location of the
periphery of the cavity are lost.
[0012] The marker clip does not aid in the healing process of the
biopsy wound. Complications may arise if the marker strays from its
original placement site. As described above, if a re-excision of
the site is required, the marker clip may also interfere when
excision of a target lesion is sought.
[0013] Other devices pertaining to biopsy aids are directed to
assisting in the healing and closure of the biopsy wound; thus they
do not aid the clinical need or desirability of accurately
preserving the location and orientation of the biopsy cavity. See,
e.g., U.S. Pat. Nos. 4,347,234, 5,388,588, 5,326,350, 5,394,886,
5,467,780, 5,571,181, and 5,676,146.
SUMMARY OF THE INVENTION
[0014] This invention relates to devices and procedures for
percutaneously marking a biopsy cavity. In particular, the
inventive device is a biopsy cavity-marking body made of a
resilient, preferably bioabsorbable material having at least one
preferably radiopaque or echogenic marker.
[0015] The device may take on a variety of shapes and sizes
tailored for the specific biopsy cavity to be filled. For example,
the device in its simplest form is a spherical or cylindrical
collagen sponge having a single radiopaque or echogenic marker
located in its geometric center. Alternatively, the body may have
multiple components linked together with multiple radiopaque or
echogenic markers.
[0016] A further aspect of the invention allows the marker or the
body, singly or in combination, to be constructed to have a varying
rate of degradation or bioabsorption. For instance, the body may be
constructed to have a layer of bioabsorbable material as an outer
"shell." Accordingly, prior to degradation of the shell, the body
is palpable. Upon degradation of the shell, the remainder of the
body would degrade at an accelerated rate in comparison to the
outer shell.
[0017] The device may additionally contain a variety of drugs, such
as hemostatic agents, pain-killing substances, or even healing or
therapeutic agents that may be delivered directly to the biopsy
cavity. Importantly, the device is capable of accurately marking a
specific location, such as the center, of the biopsy cavity, and
providing other information about the patient or the particular
biopsy or device deployed.
[0018] The device is preferably, although not necessarily,
delivered immediately after removal of the tissue specimen using
the same device used to remove the tissue specimen itself. Such
devices are described in U.S. Pat. Nos. 6,126,014 and 6,036,698,
the entirety of each are hereby incorporated by reference. The
device is compressed and loaded into the access device and
percutaneously advanced to the biopsy site where, upon exiting from
the access device, it expands to substantially fill the cavity of
the biopsy. Follow-up noninvasive detection techniques, such as
x-ray mammography or ultrasound may then be used by the physician
to identify, locate, and monitor the biopsy cavity site over a
preferred period of time.
[0019] The device is usually inserted into the body either
surgically via an opening in the body cavity, or through a
minimally invasive procedure using such devices as a catheter,
introducer or similar type device. When inserted via the minimally
invasive procedure, the resiliency of the body allows the device to
be compressed upon placement in a delivery device. Upon insertion
of the cavity marking device into the cavity, the resiliency of the
body causes the cavity marking device to self-expand, substantially
filling the cavity. The resiliency of the body can be further
pre-determined so that the body is palpable, thus allowing tactile
location by a surgeon in subsequent follow-up examinations.
Typically, the filler body is required to be palpable for
approximately 3 months. However, this period may be increased or
decreased as needed.
[0020] The expansion of the resilient body can be aided by the
addition of a bio-compatible fluid which is absorbed into the body.
For instance, the fluid can be a saline solution, a painkilling
substance, a healing agent, a therapeutic fluid, or any combination
of such fluids. The fluid or combination of fluids may be added to
and absorbed by the body of the device before or after deployment
of the device into a cavity. For example, the body of the device
may be pre-soaked with the fluid and then delivered into the
cavity. In this instance, the fluid aids the expansion of the body
of the device upon deployment. Another example is provided as the
device is delivered into the cavity without being pre-soaked. In
such a case, fluid is delivered into the cavity after the body of
the device is deployed into the cavity. Upon delivery of the fluid,
the body of the device soaks the fluid, thereby aiding the
expansion of the cavity marking device as it expands to fit the
cavity. The fluid may be, but is not limited to being, delivered by
the access device.
[0021] By "bio-compatible fluid" what is meant is a liquid,
solution, or suspension that may contain inorganic or organic
material. For instance, the bio-compatible fluid is preferably
saline solution, but may be water or contain adjuvants such as
medications to prevent infection, reduce pain, or the like.
Obviously, the liquid is intended to be a type that does no harm to
the body.
[0022] After placement of the cavity marking device into the
cavity, the bioabsorbable body degrades at a predetermined rate. As
the body of the cavity marking device is absorbed, tissue is
substituted for the bioabsorbable material. Moreover, while the
body degrades, the marker, which is usually suspended substantially
in the volumetric center of the body of the device, is left in the
center of the cavity. Thus, during a subsequent examination, a
medical practitioner having knowledge of the dimensions of the body
of the cavity marking device can determine the location as well as
the periphery of the biopsy cavity. The orientation of the cavity
is self-evident as the marker is left in substantially the center
of the cavity. For the case where multiple markers are used, the
markers are usually placed in a manner showing directionality.
[0023] Both the body and the marker can be made, via radiopaque or
echogenic coatings or in situ, to degrade and absorb into the
patient's body over a predetermined period of time. It is generally
preferred that if the marker's radiopacity or echogenicity is
chosen to degrade over time, such degradation does not take place
within at least one year after implantation of the inventive
device. In this way, if a new lump or calcification (in the case of
a breast biopsy) is discovered after the biopsy, such a marker will
allow the physician to know the relation of such new growth in
relation to the region of excised tissue. On the other hand, and as
discussed below, a bioabsorption period of three months is
preferred for any such coatings on the perimeter of the body
itself.
[0024] This invention further includes the act of filling the
biopsy cavity with a bioabsorbable liquid, aerosol or gelatinous
material, preferably gelatinous collagen, allowing the material to
partially solidify or gel and then placing a marker, which may have
a configuration as described above, into the center of the
bioabsorbable material. The gel may also be made radiopaque or
echogenic by the addition of radiopaque materials, such as barium-
or bismuth-containing compounds and the like, as well as
particulate radio-opaque fillers, e.g., powdered tantalum or
tungsten, barium carbonate, bismuth oxide, barium sulfate, to the
gel.
[0025] This method may be combined with any aspect of the
previously described devices as needed. For instance, one could
insert a hemostatic or pain-killing substance as described above
into the biopsy cavity along with the bioabsorbable material.
Alternatively, a bioabsorbable marker could be inserted into a
predetermined location, such as the center, of the body of
bioabsorbable material.
[0026] It is within the scope of this invention that either or both
of the marker or markers and the bioabsorbable body may be
radioactive, if a regimen of treatment using radioactivity is
contemplated.
[0027] This procedure may be used in any internal, preferably soft,
tissue, but is most useful in breast tissue, lung tissue, prostate
tissue, lymph gland tissue, etc. Obviously, though, treatment and
diagnosis of breast tissue problems forms the central theme of the
invention.
[0028] In contrast to the marker clips as described above, the
cavity marking device has the obvious advantage of marking the
geometric center of a biopsy cavity. Also, unlike the marking clip
which has the potential of attaching to loose tissue and moving
after initial placement, the marking device self-expands upon
insertion into the cavity, thus providing resistance against the
walls of the cavity thereby anchoring itself within the cavity. The
marking device may be configured to be substantially smaller,
larger, or equal to the size of the cavity; however, in some cases
the device will be configured to be larger than the cavity. This
aspect of the biopsy marking device provides a cosmetic benefit to
the patient, especially when the biopsy is taken from the breast.
For example, the resistance provided by the cavity marking device
against the walls of the cavity may minimize any "dimpling" effect
observed in the skin when large pieces of tissue are removed, as,
for example, during excisional biopsies.
[0029] Although the subcutaneous cavity marking device and method
described above are suited for percutaneous placement of the marker
within a biopsy cavity it is not intended that the invention is
limited to such placement. The device and method are also
appropriate for intra-operative or surgical placement of the marker
within a biopsy cavity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1A illustrates a tissue cavity marking device with a
spherical body and a single centrally-located marker.
[0031] FIG. 1B shows a tissue cavity marking device with a
cylindrical body and two ring-shaped markers aligned near the
cylinder's longitudinal axis.
[0032] FIG. 1C shows another tissue cavity marking device with a
multi-faced or irregular body and a single centrally-located
marker.
[0033] FIG. 1D illustrates a tissue cavity marking device with a
body having pores.
[0034] FIG. 1E is a partial cross-sectional view of FIG. 1D.
[0035] FIG. 1F illustrates a tissue cavity marking device with a
body having an outer shell of a bioabsorbable material.
[0036] FIGS. 2A-2F illustrate various configurations of the
marker.
[0037] FIG. 3A illustrates a cavity marking device having multiple
body components traversed by a single wire or suture marker, or
multiple wires or suture markers.
[0038] FIG. 3B illustrates a cavity marking device having a
helically wound wire or suture marker.
[0039] FIG. 3C illustrates a cavity marking device having wire or
suture markers on the perimeter of the body.
[0040] FIG. 3D illustrates a cavity marking device having wire or
markers on the ends of the body.
[0041] FIGS. 4A-4C illustrate a method of marking a biopsy tissue
cavity with the device of the present invention.
[0042] FIGS. 4D-4F illustrate a method of marking a biopsy tissue
cavity with the device of the present invention wherein a
bio-compatible fluid is delivered to the cavity marking device
after placement.
[0043] FIGS. 4G-4I illustrate a method of marking a biopsy tissue
cavity with the device of the present invention wherein a
bio-compatible fluid is used to push the cavity marking device out
of the access device and into the biopsy tissue cavity.
[0044] FIGS. 4J-4K illustrate a method of marking a biopsy tissue
cavity with the device of the present invention wherein the body
material of the marking device is deposited into the biopsy cavity
prior to the placement of the marker within the biopsy device.
[0045] FIGS. 5A-B illustrate a spherical wire marking device for
deployment without a filler body into a tissue cavity.
[0046] FIG. 5C illustrates a cylindrical wire marking device for
deployment without a filler body into a tissue cavity.
[0047] FIGS. 5D-E illustrate a helical coil wire marking device for
deployment without a filler body into a tissue cavity.
DETAILED DESCRIPTION OF THE INVENTION
[0048] FIGS. 1A-1C show various configurations of a preferred
subcutaneous cavity marking device of the present invention. Here
the marking device (100) is displayed as having either a generally
spherical body (102) (FIG. 1A), a generally cylindrical body (104)
(FIG. 1B), or a multi-faced or irregular body (106) (FIG. 1C). In
general, it is within the scope of this invention for the body to
assume a variety of shapes. For example, the body may be
constructed to have substantially curved surfaces, such as the
preferred spherical (102) and cylindrical (104) bodies of FIGS. 1A
and 1B, respectively. The body may have conical or ellipsoidal,
etc., shapes as well. It is further within the scope of this
invention for the body to have substantially planar surfaces, such
as polyhedric (i.e., cubic, tetrahedral, etc.) or prismatic, etc.,
forms. Finally, the body may also have an irregular or random
shape, in the case of a gel, combining features of various curved
and planar surfaces. Body (106) of FIG. 1C is an example of such an
irregular body shape. The particular body shape will be chosen to
best match to the biopsy cavity in which the device is placed.
However, it is also contemplated that the body shape can be chosen
to be considerably larger than the cavity. Therefore, expansion of
the device will provide a significant resistance against the walls
of the cavity. Moreover, the aspect ratio of the device is not
limited to what is displayed in the figures. For example, the
cylindrical body (104) may have a shorter or longer length as
required.
[0049] In the bodies of FIGS. 1A and 1C, the generally spherical
marker (150) is located at or near the geometric center of the
body. Such a configuration will aid the physician in determining
the exact location of the biopsy cavity, even after the body
degrades and is absorbed into the human or mammalian body.
[0050] In the case of the ring-shaped markers (154) of FIG. 1B,
they are generally aligned along the longitudinal axis (114) of
body (104). Note that although the ring-shaped markers (154) are
spatially oriented so that the longitudinal axis (114) of the body
(104) lies along the longitudinal axis (not shown) of each marker
(154), each marker may individually or together assume a wide
variety of random or predetermined spatial orientations other than
the aligned orientation as seen in FIG. 1C. It can be appreciated
that any asymmetric marker such as marker (154) is useful in aiding
a physician to determine the spatial orientation of the deployed
inventive device.
[0051] Obviously, marker (150), (154) may reside in locations other
than those demonstrated in FIGS. 1A-1C. It is, however, preferred
that markers (150), (154) dwell in a predetermined, preferably
central, location and orientation in the device body so to aid the
physician in determining the location and orientation of the biopsy
cavity. The markers herein described may be affixed to the interior
or on the surface of the body by any number of suitable methods.
For instance, the marker may be merely suspended in the interior of
the body (especially in the case where the body is a gel), it may
be woven into the body (especially in the case where the marker is
a wire or suture), it may be press fit onto the body (especially in
the case where the marker is a ring or band), or it may affixed to
the body by a biocompatible adhesive. Any suitable means to affix
or suspend the marker into the body in the preferred location is
within the scope of the present invention.
[0052] Tissue regrowth in a particular orientation can also be
promoted by a body design shown in FIG. 1D. Here, body (110)
contains a number of pores (138) through which tissue may grow. The
pores may also be aligned in a substantially parallel fashion,
traversing the thickness of the body so that tissue may regrow from
one side of the body through to the other side. This is
demonstrated in inset FIG. 1E, which shows a portion (130) of FIG.
1D in partial longitudinal cross section, complete with pores (138)
traversing through the thickness of portion (130). Such pores (138)
can be parallel to each other as shown in FIG. 1E, or they may be
perpendicularly, radially, or even randomly oriented in the device
body.
[0053] A trio of markers is also shown in FIG. 1D evenly aligned
along the body longitudinal axis (140). Barb marker (156),
spherical marker (150), and ring-shaped marker (154) demonstrate
the use of different multiple markers in a single body (110). As
previously described, such a design helps a physician to determine
the spatial orientation of the inventive device when it is deployed
in a biopsy cavity. Although the barb marker (156) is illustrated
in a `V` configuration, it is an important aspect of the barb
marker (156) to have a shape that is clearly not spherical. This
allows the barb marker (156) to be easily distinguished from
calcifications that may be observed during any non-invasive imaging
techniques.
[0054] FIG. 1F depicts a further embodiment of the present
invention in which body (112) is enveloped in an outer shell (142)
consisting of a layer of bioabsorbable material such those
mentioned above. This configuration allows the perimeter of the
biopsy cavity to be marked to avoid exposing the cavity, in the
case of a "dirty" margin where re-excision may be necessary, to
remaining cancerous cells as the tissue begins to re-grow into the
cavity. Such a shell (142) can be radiopaque and/or echogenic in
situ, or it may be augmented with an additional coating of an
echogenic and/or radiopaque material. The shell (142) can also be
made to be palpable so that the physician or patient can be further
aided in determining the location and integrity of the implanted
inventive device.
[0055] Shell (142) may be designed to have a varying bioabsorption
rate depending upon the thickness and type of material making up
the shell (142). In general, the shell can be designed to degrade
over a period ranging from as long as a year or more to as little
as several months, weeks, or even days. It is preferred that such a
bioabsorbable shell be designed to degrade between two and six
months; especially preferred is three months. In the design of FIG.
1F, interior (144) of body (112) may be a cross-linked, collagenous
material that is readily absorbed by the human or mammalian body
once the shell (142) degrades. Interior (144) may be filled with a
solid or gelatinous material that can be optionally made radiopaque
by any number of techniques herein described.
[0056] As will be described in additional detail with respect to
FIGS. 2A-2F, marker (150) in the device shown in FIG. 1F may be
permanently radiopaque or echogenic, or it also may be
bioabsorbable and optionally coated with a radiopaque and/or
echogenic coating that similarly degrades over a predetermined
period of time. It is more important from a clinical standpoint
that the marker remain detectable either permanently or, if the
patient is uncomfortable with such a scenario, for at least a
period of about one to five years so that the physician may follow
up with the patient to ensure the health of the tissue in the
vicinity of the biopsy cavity. Especially preferable is a marker
whose radiopacity or echogenicity lasts from between about one and
three years.
[0057] Each of the bodies depicted in FIGS. 1A-1E may be made from
a wide variety of solid, liquid, aerosol-spray, spongy, or
expanding gelatinous bioabsorbable materials such as collagen,
cross-linked collagen, regenerated cellulose, synthetic polymers,
synthetic proteins, and combinations thereof. Also contemplated is
a body made from a fibrin-collagen matrix, which further prevent
unnecessary bleeding, and minimizes the possibility of hematoma
formation.
[0058] Examples of synthetic bioabsorbable polymers that may be
used for the body of the device are polyglycolide, or polyglycolic
acid (PGA), polylactide, or polylactic acid (PLA), poly
.epsilon.-caprolactone, polydioxanone, polylactide-co-glycolide,
e.g., block or random copolymers of PGA and PLA, and other
commercial bioabsorbable medical polymers. Preferred is spongy
collagen or cellulose. As mentioned above, materials such as
hemostatic and pain-killing substances may be incorporated into the
body and marker of the cavity marking device. The use of
hemostasis-promoting agents provides an obvious benefit as the
device not only marks the site of the biopsy cavity but it aids in
healing the cavity as well. Furthermore, such agents help to avoid
hematomas. These hemostatic agents may include AVITENE
Microfibrillar Collagen Hemostat, ACTIFOAM collagen sponge, sold by
C. R. Bard Inc., GELFOAM, manufactured by Upjohn Company, SURGICEL
Fibrillar from Ethicon Endosurgeries, Inc., and TISSEEL VH, a
surgical fibrin sealant sold by Baxter Healthcare Corp. The device
may also be made to emit therapeutic radiation to preferentially
treat any suspect tissue remaining in or around the margin of the
biopsy cavity. It is envisioned that the marker would be the best
vehicle for dispensing such local radiation treatment or similar
therapy. Also, the body itself may be adapted to have radiopaque,
echogenic, or other characteristics that allow the body to be
located by non-invasive technique without the use of a marker. Such
characteristics permit the possibility of locating and
substantially identifying the cavity periphery after deployment but
prior to absorption of the device. Furthermore, an echogenic
coating may be placed over the radiopaque marker to increase the
accuracy of locating the marker during ultrasound imaging.
[0059] FIGS. 2A-2F illustrate various forms of the marker (110).
The marker (110) may be in the form of a sphere (150) (FIG. 2A), a
hollow sphere (152) (FIG. 2B), a ring or band (154) (FIG. 2C), a
barb (156) (FIG. 2D), or a flexible suture or flexible wire (158)
(FIG. 2E). Also, the marker may have a distinguishing mark (170)
(FIG. 2F). As mentioned above, the barb (156) is illustrated in
FIG. 2D as having a "V" shape. The barb (156) is intended to
distinguish the marker from calcifications when viewed under
non-invasive imaging techniques. As such, the barb (156) is not
limited to the "V" shape; rather it has a shape that is easily
distinguishable from a spherical or oval calcification.
[0060] The hollow sphere (152) marker design of FIG. 2B is more
susceptible to detection by ultrasound than the solid sphere (150)
of FIG. 2A. Such sphere markers (150, 152) can be a silicon bead,
for instance. In the case of a ring or band marker (154) seen in
FIG. 2C, the body of the cavity marking device may be woven or
placed through the band/ring (154). The marker may also be a wire
or suture (158) as shown in FIG. 2E and as discussed in greater
detail below. In such a case, the marker (158) may be affixed to
the exterior perimeter of the body by an adhesive or woven through
the body. Another improvement may arise from the marker wire or
suture (158) being configured in a particular pattern within the
body of the device, e.g., wrapping around the body in a helical
manner. Further, the suture or wire marker can be deployed as a
loosely wound ball or mass of suture that when deployed into a
tissue cavity, fills the cavity. The suture or wire can also looped
through the band/ring (154); in this configuration (not shown), the
suture or wire can also act as the body of the inventive device.
The suture or wire (158) is flexible to facilitate the expansion of
the body while in the cavity. In the case of the marker (150) shown
in FIG. 2F, distinguishing or identifying mark (170) can be in the
form of simple marks as shown, or it may be one or more numbers,
letters, symbols, or combinations thereof. These marks (170) are
preferably located in more than one location on the marker (150) so
that the marker may be readily and simply identified from multiple
orientations under a variety of viewing conditions. Such a mark
(170) can be used to identify the patient and her condition,
provide information about the marker and body of the tissue cavity
marking device, provide information about the circumstances and
date of the implantation, who performed the procedure, where the
procedure was performed, etc. In the case of multiple biopsy sites,
this distinguishing mark (170) permits one to differentiate and
identify each different site. The mark (170) may be applied via any
number of techniques such as physical inscription, physical or
plasma deposition, casting, adhesives, etc. The mark (170) may also
be an electronic chip providing any necessary information in
electronic form that can be remotely detected by appropriate
means.
[0061] An important aspect of the invention is that the marker may
be radiopaque, echogenic, mammographic, etc., so that it can be
located by non-invasive techniques. Such a feature can be an
inherent property of the material used for the marker.
Alternatively, a coating or the like can be added to the marker to
render the marker detectable or to enhance its detectability. For
radiopacity, the marker may be made of a non-bioabsorbable
radiopaque material such as platinum, platinum-iridium,
platinum-nickel, platinum-tungsten, gold, silver, rhodium,
tungsten, tantalum, titanium, nickel, nickel-titanium, their
alloys, and stainless steel or any combination of these metals. By
mammographic we mean that the component described is visible under
radiography or any other traditional or advanced mammography
technique in which breast tissue is imaged.
[0062] As previously discussed, the marker can alternatively be
made of or coated with a bioabsorbable material. In this case, the
marker can, for instance, be made from an additive-loaded polymer.
The additive is a radiopaque, echogenic, or other type of substance
that allows for the non-invasive detection of the marker. In the
case of radiopaque additives, elements such as barium- and
bismuth-containing compounds, as well as particulate radio-opaque
fillers, e.g., powdered tantalum or tungsten, barium carbonate,
bismuth oxide, barium sulfate, etc., are preferred. To aid in
detection by ultrasound or similar imaging techniques, any
component of the device may be combined with an echogenic coating.
One such coating is ECHO-COAT from STS Biopolymers. Such coatings
contain echogenic features which provide the coated item with an
acoustically reflective interface and a large acoustical impedance
differential. As stated above, an echogenic coating may be placed
over a radiopaque marker to increase the accuracy of locating the
marker during ultrasound imaging.
[0063] Note that the radiopacity and echogenicity described herein
for the marker and the body are not mutually exclusive. It is
within the scope of the present invention for the marker or the
body to be radiopaque but not necessarily echogenic, and for the
marker or the body to be echogenic but not necessarily radiopaque.
It is also within the scope of the invention that the marker and
the body are both capable of being simultaneously radiopaque and
echogenic. For example, if a platinum ring marker were coated with
an echogenic coating, such a marker would be readily visible under
x-ray and ultrasonic energy. A similar configuration can be
envisioned for the body or for a body coating.
[0064] The marker is preferably large enough to be readily visible
to the physician under x-ray or ultrasonic viewing, for example,
yet be small enough to be able to be percutaneously deployed into
the biopsy cavity and to not cause any difficulties with the
patient. More specifically, the marker will not be large enough to
be palpable or felt by the patient.
[0065] Another useful version of the invention is shown in FIG. 3A.
In this device, there are several cylindrical body members (302);
however, there is no limit to the number of body members that can
make up the device. The body members (302) can individually or
together take on a variety of sizes and shapes as discussed above
depending on the characteristics of the biopsy cavity to be filled.
The body members (302) may uniformly or in combination be made of
one or more materials suitable for use in a biopsy cavity as
previously described.
[0066] Here one or more markers may traverse two or more body
member segments through the interior of the body members (302) as
shown in FIG. 3A. Here, markers (318) are located substantially
parallel to the longitudinal axis (320) of each right cylindrical
body member (302) in their interior, connecting each body member
(302) while marking their geometric center as between the markers.
Such a marker (318) may be used in conjunction with the other
markers as described above and may also be accompanied by one or
more additional markers arranged randomly or in a predetermined
pattern to variously mark particular sections of the device.
Alternately, such a marker may, singly or in combination with other
markers, be affixed on or near the surface of the sponge so as to
mark the perimeter of the body member (302).
[0067] Of course, when used in conjunction with other connecting
markers, marker (318) need not necessarily connect each body
member; it may be used solely to indicate the orientation or
location of each individual sponge or the entire device, depending
on the material, geometry, size, orientation, etc., of marker
(318). When not used in this connecting function, therefore, marker
(318) need not traverse two body members (302) as shown in FIG.
3A.
[0068] A variety of patterns can be envisioned in which all or part
of the perimeter of the sponge body is marked. For example, a
marker (322) can wrap around the body (302) in a helical pattern
(FIG. 3B), or it can be used in conjunction with other markers
(324) in a pattern parallel to the longitudinal axis (320) of the
body (FIG. 3C). Another useful perimeter marking pattern is shown
in FIG. 3D, where marker segments (326) are affixed at or near the
surface of the circular bases of the cylindrical body (302) in a
cross pattern, indicating the ends of the sponge and their center.
As seen form the figures, the markers(s) may, but do not
necessarily, have some texture. Any marker pattern, internal or
external to the body, is within the scope of the present invention.
For the applications depicted in FIGS. 3A-3D, it is preferred that
the marker be a radiopaque or echogenic wire or suture.
[0069] Another possible configuration is obtained by combining the
suture or wire markers (158) in a body with any other type marker
(150, 152, 154, or 156) or vice versa. For example, in FIG. 3B, a
spherical marker (150) may be placed in the center of the
cylindrical body (302.) Therefore, the cylindrical body (302) would
contain the suture or wire marker (322) wrapped helically adjacent
to the outer perimeter, and a marker (150) would be placed in the
center of the cylindrical body (302). Such a combination may be
obtained with any of the body and marker configurations as defined
above.
[0070] Also, turning back to the marking device (100) in FIG. 1A or
the marking device (100) of FIG. 1B, the markers (150 or 154) may
be substituted with one or more suture or wire markers (158)
preferably, but not exclusively, extending through the center and
pointing radially away from the center. This configuration allows
marking of the cavity perimeter and establishing of the
directionality of the cavity itself.
[0071] Any of the previously-described additional features of the
inventive device, such as presence of pain-killing or hemostatic
drugs, the capacity for the marker to emit therapeutic radiation
for the treatment of various cancers, the various materials that
may make up the marker and body, as well as their size, shape,
orientation, geometry, etc., may be incorporated into the device
described above in conjunction with FIGS. 3A-3D.
[0072] Turning now to FIGS. 4A-4C, a method of delivering the
inventive device of FIG. 1A is shown. FIG. 4A details the marking
device (402) just prior to delivery into a tissue cavity (404) of
human or other mammalian tissue, preferably breast tissue (406). As
can be seen, the step illustrated in FIG. 4A shows a suitable
tubular percutaneous access device (400), such as a catheter or
delivery tube, with a distal end (408) disposed in the interior of
cavity (404). As previously described, the marking device (402) may
be delivered percutaneously through the same access device (400)
used to perform the biopsy in which tissue was removed from cavity
(404). Although this is not necessary, it is less traumatic to the
patient and allows more precise placement of the marking device
(402) before fluid begins to fill the cavity (400).
[0073] In FIG. 4B, marking device (402) is shown being pushed out
of the distal end (408) of access device (400) by a pusher (412)
and resiliently expanding to substantially fill the tissue cavity
(404).
[0074] Finally, in FIG. 4C, access device (400) is withdrawn from
the breast tissue, leaving marking device (402) deployed to
substantially fill the entire cavity (404) with radiopaque or
echogenic marker (410) suspended in the geometric center of the
marking device (402) and the cavity (404). As mentioned above, the
marking device (402) may be sized to be larger than the cavity
(404) thus providing a significant resistance against the walls of
the cavity (404).
[0075] FIGS. 4D-4F show a method of delivering the marking device
(402) into a tissue cavity (404) by a plunger (414) that is capable
of both advancing the marking device (402) and delivering a
bio-compatible fluid (416). The "bio-compatible fluid" is a liquid,
solution, or suspension that may contain inorganic or organic
material. The fluid (416) is preferably a saline solution, but may
be water or contain adjuvants such as medications to prevent
infection, reduce pain, or the like. Obviously, the fluid (416) is
intended to be a type that does no harm to the body.
[0076] FIG. 4D details the marking device (402) prior to delivery
into the tissue cavity (404). In FIG. 4E, a plunger (414) pushes
the marking device (402) out of the access device (400). Upon
exiting the access device (400) the marking device (402) begins
resiliently expanding to substantially fill the cavity (404).
[0077] FIG. 4F shows the plunger (414) delivering the
bio-compatible fluid (416) into the cavity (404). The fluid (416)
aids the marking device (402) in expanding to substantially fill
the cavity (404). In this example, the bio-compatible fluid (416)
is delivered subsequent to the placement of the marking device
(402) in the cavity (404). The marking device (402) may also be
soaked with fluid (416) prior to placement in the cavity (404).
[0078] FIGS. 4G-4I show another method of delivering the marking
device (402) into the tissue cavity (404) by using the
bio-compatible fluid (416) as the force to deliver the marking
device (402) into the tissue cavity (404).
[0079] FIG. 4G details the marking device (402) prior to delivery
into the tissue cavity (404). FIG. 4H illustrates flow of the
bio-compatible fluid (416) in the access device (400), the fluid
(416) flow then pushes the marking device (402) out of the access
device (400).
[0080] FIG. 4I shows the delivery device (400) continuing to
deliver the bio-compatible fluid (416) into the cavity (404). The
fluid (416) aids the marking device (402) in expanding to
substantially fill the cavity (404). In this example, the
bio-compatible fluid (416) is delivered after the placement of the
marking device (402) in the cavity (404) although the invention is
not limited to the continued delivery of the fluid (416).
[0081] FIG. 4J-4K shows the method of delivering the body (418) of
the cavity marking device directly into the cavity (404) prior to
the placement of the marker (410) in the device (402).
[0082] FIG. 4J shows the deposit of the body material (418) into
the cavity (404). In this case the body material (418) may be a gel
type material as described above. FIG. 4K details the filling of
the cavity (404) with the body material (418). At this point, the
delivery device (not shown in FIG. 4K) may be withdrawn. FIG. 4L
details the placement of the marker (410) into the body material
(418).
[0083] FIGS. 5A-5E show yet another version of the invention in
which a marker, preferably consisting of a radiopaque or echogenic
wire, is deployed alone into a tissue cavity without the use of any
body. In this device, the marker can be made of a shape memory
material, such as a nickel-titanium alloy, which when deployed into
the biopsy cavity, assumes a predetermined configuration to
substantially fill the cavity, mark the cavity location and margin,
and indicate the orientation of the marker inside the cavity.
[0084] In FIG. 5A, marker (500) is a three-dimensional sphere
consisting of two rings (502),
[0085] (504) pivotally connected at ends (506), (508) so to assume
a spherical shape. Such a marker can be made of a shape memory
metal so that when it is placed in a deployment tube (510) shown in
FIG. 5B, marker (500) assumes a collapsed profile suitable for
deployment through tube (510) by pusher (512). Upon exiting into
the tissue cavity (not shown), marker (500) assumes the spherical
shape of FIG. 5A to fill the cavity. The marker (500) may also be
shaped into any similar shape such as an ellipsoidal shape.
[0086] Turning now to FIG. 5C, a marker (520) in the form of a wire
cylinder is shown. Again, this device is structurally configured to
assume the depicted cylindrical configuration when deployed in the
tissue cavity, but may be (as described above) "collapsed" into a
deployment tube for percutaneous delivery. This device is
especially suitable for marking the distal and proximal ends of the
tissue cavity due to its asymmetrical shape.
[0087] FIG. 5D shows a shape memory marker (530) in the form of a
helical coil deployed into tissue cavity (532). Again, as seen in
FIG. 5E, such a marker (530) may be deployed through delivery tube
(510) by pusher (512) in a substantially elongated, straightened
form, only to substantially assume the shape of the cavity (532) as
shown in FIG. 5D. Any suitable delivery device or pusher (512)
capable of deploying marker (530) into cavity (532) is within the
scope of this invention.
[0088] Each of the markers shown in FIGS. 5A-5E is preferably a
shape memory material coated or supplemented with a
radiopacity-enhancing material, such as gold, platinum, or any
other radiopaque material herein discussed. The markers may singly,
or in combination with being radiopaque, be echogenic or be made
echogenic by any of the materials or methods herein described.
[0089] From the foregoing, it is understood that the invention
provides an improved subcutaneous cavity marking device and method.
While the above descriptions have described the invention for use
in the marking of biopsy cavities, the invention is not limited to
such. One such application is evident as the invention may further
be used as a lumpectomy site marker. In this use, the cavity
marking device yield an improved benefit by marking the perimeter
of the lumpectomy cavity.
[0090] The invention herein has been described by examples and a
particularly desired way of practicing the invention has been
described. However, the invention as claimed herein is not limited
to that specific description in any manner. Equivalence to the
description as hereinafter claimed is considered to be within the
scope of protection of this patent.
* * * * *