U.S. patent application number 12/578088 was filed with the patent office on 2010-02-04 for absorbable sponge with contrasting agent.
This patent application is currently assigned to BOSTON SCIENTIFIC SCIMED, INC.. Invention is credited to Mark Ashby, Eduardo Chi Sing.
Application Number | 20100029908 12/578088 |
Document ID | / |
Family ID | 23311845 |
Filed Date | 2010-02-04 |
United States Patent
Application |
20100029908 |
Kind Code |
A1 |
Sing; Eduardo Chi ; et
al. |
February 4, 2010 |
ABSORBABLE SPONGE WITH CONTRASTING AGENT
Abstract
An absorbable sponge containing a contrasting agent (e.g.,
radiopaque agent) that can be introduced to a biopsy tract or other
puncture wound site is provided. The contrasting agent permits
identification of the site by fluoroscopy or other imaging
techniques.
Inventors: |
Sing; Eduardo Chi; (Dana
Point, CA) ; Ashby; Mark; (Laguna Niguel,
CA) |
Correspondence
Address: |
CROMPTON, SEAGER & TUFTE, LLC
1221 NICOLLET AVENUE, SUITE 800
MINNEAPOLIS
MN
55403-2420
US
|
Assignee: |
BOSTON SCIENTIFIC SCIMED,
INC.
Maple Grove
MN
|
Family ID: |
23311845 |
Appl. No.: |
12/578088 |
Filed: |
October 13, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10978321 |
Oct 29, 2004 |
7618567 |
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12578088 |
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09966611 |
Sep 27, 2001 |
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10978321 |
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09630814 |
Aug 2, 2000 |
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09966611 |
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09335452 |
Jun 17, 1999 |
6183497 |
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09630814 |
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09071670 |
May 1, 1998 |
6071301 |
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09335452 |
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09071284 |
May 1, 1998 |
6162192 |
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09071670 |
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Current U.S.
Class: |
530/354 |
Current CPC
Class: |
A61B 6/03 20130101; A61B
6/485 20130101; A61B 17/0057 20130101; A61M 31/005 20130101; A61B
2017/00004 20130101; A61B 2017/00637 20130101; A61B 2017/00654
20130101; A61B 6/481 20130101; A61B 8/481 20130101; A61B 10/0233
20130101; A61B 2090/3933 20160201; A61B 90/39 20160201 |
Class at
Publication: |
530/354 |
International
Class: |
C07K 14/00 20060101
C07K014/00 |
Claims
1. A liquid permeable, absorbable gelatin sponge that is prepared
by a process that comprises: (a) preparing an aqueous gelatin
solution; (b) adding an organic solvent in the aqueous gelatin
solution to form a second solution; (c) incubating the second
solution; (d) forming a foam from the second solution wherein a
contrasting agent is added to the second solution at any step prior
to forming the foam; and (e) drying the foam.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 10/978,321, filed Oct. 29, 2004; which is a divisional of U.S.
application Ser. No. 09/966,611, filed Sep. 27, 2001, now
abandoned, which is a continuation of U.S. application Ser. No.
09/630,814, filed Aug. 2, 2000, now abandoned, which is a
divisional of U.S. application Ser. No. 09/335,452, filed Jun. 17,
1999, now U.S. Pat. No. 6,183,497, which is a continuation in part
of U.S. application Ser. No. 09/071,670, filed May 1, 1998, now
U.S. Pat. No. 6,071,301 and U.S. application Ser. No. 09/071,284,
filed May 1, 1998, now U.S. Pat. No. 6,162,192.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to an absorbable sponge, and more
particularly, the invention relates to the delivery of a
contrasting agent to a specific area or site in a mammal after a
surgical or interventional procedure. The contrasting agent
facilitates the location of the area or site even weeks or months
after the initial procedure.
[0004] 2. Brief Description of the Related Art
[0005] Percutaneous needle biopsy of solid organs is one of the
most common interventional medical procedures. Millions of
percutaneous needle biopsies are performed annually in the United
States and throughout the world. Percutaneous biopsy is a safe
procedure which has supplanted surgical biopsy for many
indications, such as biopsy and liver biopsy.
[0006] Possible complications of needle biopsy include bleeding at
the biopsy site. The amount of bleeding is related to a number of
factors including needle size, tissue sample size, patient's
coagulation status, and the location of the biopsy site. Vascular
organs such as the liver, a common biopsy target, may bleed
significantly after needle biopsy.
[0007] Sterile sponges, such as GELFOAM, are prepared in dry
sterile sheets which are used as packing material during surgery
for control of bleeding. The sponge sheets are left in the surgical
site after surgery to stop bleeding and are absorbed by the body. A
number of techniques have used these absorbable sterile sponge
materials to plug a biopsy tract to minimize or prevent bleeding.
The absorbable sponge provides a mechanical blockage of the tract,
encourages clotting, and minimizes bleeding though the biopsy
tract.
[0008] During the biopsy, a mechanic clip device is often attached
to the site where tissue is removed, so that if further treatment
is later required the location of the site can be identified.
Unfortunately, the time period between the biopsy and treatment may
be weeks during which time the clip may become dislodged thereby
making it difficult to relocate the site.
[0009] Accordingly, it would be desirable to provide a reliable
technique for identifying biopsy sites or puncture wound sites.
SUMMARY OF THE INVENTION
[0010] The present invention is based in part on the discovery that
adding a contrasting agent (e.g., radiopaque agent) to an
absorbable sponge provides for a material that not only facilitates
hemostasis of a biopsy tract or other puncture wound but also
permits precise identification of the site's location.
[0011] Accordingly, in one aspect, the invention is directed to a
method for marking a bodily site in a patient that includes the
steps of:
[0012] identifying the bodily site; and
[0013] positioning a pledget of absorbable sponge material adjacent
the bodily site wherein the absorbable sponge material includes a
contrasting agent.
[0014] With the present invention, the exact location of the bodily
site can be located many weeks or longer following positioning of
the absorbable sponge material.
[0015] In another aspect, the invention is directed to a method for
performing a biopsy that included the steps of:
[0016] removing tissue from a vascular tissue site; and
[0017] positioning a pledget of absorbable sponge material adjacent
the vascular tissue site wherein the absorbable sponge material
includes a contrasting agent.
[0018] In another aspect, the invention is directed to a liquid
permeable, absorbable, gelatin sponge that is prepared by a process
that includes the steps of:
[0019] (a) preparing an aqueous gelatin solution;
[0020] (b) adding an organic solvent in the aqueous gelatin
solution to form a second solution;
[0021] (c) incubating the second solution;
[0022] (d) forming a foam from the second solution wherein a
contrasting agent is added to the second solution at any step prior
to forming the foam; and
[0023] (e) drying the foam.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention will now be described in greater detail with
referee to the preferred embodiments illustrated in the
accompanying drawings, in which like elements bear like reference
numerals, and wherein:
[0025] FIG. 1 is a side cross sectional view of an adaptor for
delivery of a pledget to a needle;
[0026] FIG. 2 is a side cross sectional view of a syringe for
connection to the adaptor;
[0027] FIG. 3 is a side cross sectional view of an adaptor and
syringe combination with a pledget positioned within the
adaptor;
[0028] FIG. 4 is a side cross sectional view of the loaded adaptor
and syringe combination in preparation for connection to a biopsy
needle;
[0029] FIG. 5 is a side cross sectional view of an alternative
embodiment of an adaptor for delivery of a pledget including a
template attached to the adaptor;
[0030] FIG. 6 is a top view of the template as it is used for
cutting a pledget from an absorbable sponge sheet; and
[0031] FIG. 7 is a side cross sectional view of a portion of an
organ and a system for delivering a pledget into a biopsy tract in
the organ.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] The present invention is directed to an absorbable sponge
material containing a contrasting agent. The absorbable sponge
material is delivered to a specific area or site in a patient
(i.e., mammal) after a surgical or interventional procedure. For
example, the sponge material can be placed in the biopsy tract or
other puncture wound and the contrasting agent enables marking or
identification of the area or site. The absorbable sponge will be
described in connection with treatment of a biopsy tract after a
percutaneous needle biopsy. The absorbable sponge material can also
exhibit secondary benefits of, for example, facilitating hemostasis
and delivering therapeutic agents.
[0033] Prior to discussing the present invention in further detail,
the following terms are defined:
[0034] "Pledget" means a piece of absorbable sponge containing a
contrasting agent preferably of a generally elongated shape having
a size which allows injection in a hydrated state through a biopsy
needle or other cannula.
[0035] "Sponge" means a biocompatible material which is capable of
being hydrated and is resiliently compressible in a hydrated state.
Preferably, the sponge is non-immunogenic and is absorbable.
[0036] "Absorbable sponge" means a sponge which when implanted
within a patient (i.e., human or other mammalian body) is absorbed
by the body. The absorbable sponge contains a contrasting agent
which may or may not be absorbable. Besides the contrasting agent,
the sponge can also be used to deliver a beneficial agent such as
thrombin, radiation treatment or the like.
[0037] "Bodily site" means any tissue in a mammal where the
absorbable sponge containing the contrasting agent can be
introduced. The invention is particularly suited for introducing
the absorbable sponge into tissue sites where further treatment may
be required, for example, as in the case following biopsy.
[0038] "Hydrate" means to partially or fully saturate with a fluid,
such as, saline, water, or the like.
[0039] "Kneading" of the absorbable sponge material means both dry
and wet manipulation of the sponge material which compresses,
enlarges, or changes the shape of the sponge material causing the
sponge material to have improved expansion response.
[0040] "Contrasting agent" means a biocompatible material that is
capable of being detected or monitored by fluoroscopy, X-ray
photography, CAT scan, ultrasound, or similar imaging techniques
following placement into a mammalian subject. Preferred contrasting
agents are radiopaque materials. The contrast agent can be either
water soluble or water insoluble. Examples of water soluble
contrast agents include metrizamide, iopamidol, iothalamate sodium,
iodomide sodium, and meglumine. Examples of water insoluble
contrast agents include tantalum, tantalum oxide, and barium
sulfate, each of which is commercially available. Other water
insoluble contrast agents include gold, tungsten, and platinum
powders. Some radiopaque contrasting agents are available in liquid
form. These include, for example, OMNIPAQUE from Nycomed, Inc.,
Princeton, N.J. Preferably, the contrast agent is water insoluble
(i.e., has a water solubility of less than 0.01 mg/ml at 20.degree.
C.).
[0041] The absorbable sponge material of the present invention is
preferably a liquid permeable, water insoluble gelatin based sponge
that has contrasting agent incorporated in the matrix of the
sponge. By "incorporated" is meant that the contrasting agent is
substantially dispersed throughout the sponge so that the
contrasting material is not simply found on the periphery of the
sponge. The sponge is made by mixing a suitable organic solvent
(e.g., formaldehyde) with an aqueous solution of gelatin. The
organic solvent facilitates the cross linkage of gelatin polymers.
It is expected that glutaraldehyde may also be suitable. The
resulting solution is then incubated typically at slightly above
room temperature (30.degree.-40.degree. C.). Subsequently, a
contrasting agent is added and the resulting mixture beaten to
produce a firm foam. Thereafter, the foam is dried to produce the
absorbable sponge material.
[0042] Typically, the aqueous gelatin solution containing 3-10%
gelatin by weight is prepared as a warm solution (e.g., 80.degree.
C.) to help dissolve the gelatin. The solution is then allowed to
cool (e.g., 35.degree.-40.degree. C.) before the organic solvent is
added. A preferred organic solvent is formalin (an aqueous solution
of formaldehyde). The amount of formalin used will control the
hardness of the sponge and its rate of absorption into the body.
The more formalin used, the harder the sponge and the lower the
absorption rate. Typically, the amount used is between 0.01 to 10%
based on the gelatin solution. The beating or whipping process
takes about 5-15 or more minutes to produce a firm foam of about 4
to 8 times the volume of the original solution. The drying process
initially begins with oven drying in the presence of circulating
air at about 30.degree. to 33.degree. C. or higher and 10%
humidity. After the foam is thoroughly dried, the foam can be
heated to an elevated temperature of about 140.degree. C. for a
sufficient length of time (e.g., 3 hrs) until the sponge is firm.
Suitable absorbable sponge materials are further described in U.S.
Pat. No. 2,465,357 which is incorporated herein by reference.
[0043] It has been found that at least for contrasting agents that
are not soluble in water, the contrasting agent must be added prior
to beating the gelatin/formalin solution. The reason is that once
the foam material is produced, the contrasting agent cannot be
incorporated into the matrix of the sponge.
[0044] When employing contrasting agents that are liquids it is
preferred that they be added to the gelatin/formalin solution prior
to being beaten to form the foam product. This will insure that the
contrasting agent is dispersed throughout the sponge.
[0045] Care should be taken when using insoluble contrasting agents
not to overload the absorbable sponge material by using excessive
amounts of contrasting agents. This will possibly result in sponges
that have reduced cell structures, that is, the final volume will
be significantly less than if no contrasting agent was used.
[0046] Following the above formulation, absorbable sponge materials
containing different amounts of contrasting agent were prepared and
tested. Specifically, 5 grams of pork gelatin (Bloom value 275)
were mixed in 100 grams of water at 80.degree. C. and the solution
was allowed to cool to 35.degree. C. before 0.03 cc of 40% formalin
was added. The resulting solution was incubated at 35.degree. C.
for 2 hours before tantalum powder (50 to 150 grams) was added. The
liquid was then vigorously mixed in a malt mixer to produce a foam.
The foam was then oven dried at 35.degree. C. for 12 hours.
[0047] The absorbable sponge material was examined with a
fluoroscope and found to be extremely visible. Moreover, placement
of the sponge material with contrasting agent in puncture sites of
a swine model demonstrated that the absorbable sponge exhibited
good hemostatic properties as well.
[0048] The sponge material with contrasting agent of the present
invention is particularly suited for biopsies and other
percutaneous procedures where knowledge of the site of initial
treatment, e.g., tissue removal, is important.
[0049] While the absorbable sponge material can be employed with
any suitable medical instrument, a preferred device and method for
facilitating hemostasis of a biopsy tract is described herein to
illustrate use of the absorbable sponge material. The technique is
further described in U.S. patent application Ser. No. 09/247,880
filed on Feb. 10, 1999 and entitled "Device and Method for
Facilitating Hemostasis of a Biopsy Tract," now U.S. Pat. No.
6,086,607, which is incorporated herein by reference.
[0050] FIG. 1 shows the adaptor 12 in which the pledget 18 is
placed for hydration and for delivery through the biopsy needle 16.
The adaptor 12 allows pieces of absorbable sponge material with
relatively large cross sections to be easily delivered through a
biopsy needle 16 with a much smaller cross section. The adaptor 12
also functions to remove air from the pledget 18.
[0051] The adaptor 12 which delivers the hydrated pledget 18 to the
needle 16 includes a first end 30 having an annular lip 32 or
female luer fitting for connection to the syringe 14. A second end
34 of the adaptor 12 has a male luer fitting 36 for connection to a
biopsy needle 16 or other cannula. The luer fitting 36 includes a
tapered external surface 38 and a retaining ring 40 with internal
threads for receiving an annular lip of the biopsy needle. The
adaptor 12 has an internal lumen with a first diameter D.sub.1 at
the first end 30 and a second diameter D.sub.2 at the second end
34. Between the first and second ends of the adaptor 12 a tapered
section 42 of the adaptor provides a funnel for compressing the
hydrated pledget 18 prior to injection through the biopsy needle 16
and needle hub 28.
[0052] The adaptor 12 may be formed in any known manner such as by
molding from a plastic material. Preferably, the adaptor 12 is
transparent so that the pledget 18 can be viewed through the
adaptor and the user can visually monitor when the pledget is
loaded within the adaptor and when the pledget has been delivered
into the needle. The adaptor lumen may be provided with a friction
reducing coating for improved delivery. The delivery fluid also
reduces friction for improved delivery by wetting the exterior
surface of the pledget 18.
[0053] As shown in FIG. 2, the syringe 14 includes a male luer
fitting 46, a fluid chamber 48, and a plunger 50. The first end 30
of the adaptor 12 is connectable to the luer fitting 46 of the
conventional syringe 14. The syringe 14 may be provided with a
spring 52 for automatic filling of the syringe 14 with a
predetermined volume of fluid.
[0054] The biopsy needle 16 used with the present invention is
preferably a co-axial biopsy needle, such as a bi-axial or a
tri-axial biopsy needle. A co-axial biopsy needle includes an outer
needle or cannula through which a tissue sample is removed with a
tissue scoop or other biopsy instrument. Once the tissue sample has
been removed, the outer cannula remains in the patient as
illustrated in FIG. 4. Although the cannula for delivery of the
sponge pledget has been described as a biopsy needle, the cannula
may be a catheter, sheath, or any other type of cannula.
[0055] A preferred method of facilitating hemostasis of a biopsy
tract will be described with reference to FIG. 3 which shows the
loading and hydration of the pledget 18 within the adaptor 12. A
pledget 18 is cut and placed within the adaptor 12 from the first
end 30 of the adaptor. The syringe 14 is filled with a
predetermined amount of fluid, such as saline, and is connected to
the first end 30 of the adaptor 12 by the luer fitting 46. The
plunger 50 of the syringe 14 is then depressed slowly causing fluid
to pass into the adaptor 12, hydrating the pledget 18, and filling
the adaptor with a column of fluid. Care should be taken to inject
the fluid slowly to prevent the pledget from being ejected out of
the second end 34 of the adaptor. Preferably, the user waits a few
seconds once the fluid is injected into the adaptor 12 until the
pledget 18 is adequately hydrated creating a lubricous surface on
the pledget. The pledget 18 may expand within the adaptor to fill
or nearly fill the lumen of the adaptor. The adaptor 12 with the
pledget 18 hydrated within the proximal end is ready to inject the
pledget into a biopsy tract to facilitate hemostasis within the
biopsy tract. The adaptor 12 may be loaded prior to beginning the
biopsy procedure.
[0056] After the biopsy procedure has been completed, the outer
sheath of the biopsy needle 16 through which the biopsy has been
taken is maintained in place within the biopsy tract, as shown in
FIG. 4. The biopsy needle 16 provides pre-established targeting of
the delivery site for delivery of the absorbable sponge pledget 18
and eliminates the uncertainty of re-access. The luer fitting 36 of
the adaptor 12 is connected to the biopsy needle hub 28, as
illustrated in FIG. 4. The biopsy needle 16 is withdrawn a short
distance, such as about 1 to 20 mm, along the biopsy tract to
provide space for the pledget 18 to be received in the biopsy
tract. Additional fluid is then rapidly injected by the syringe to
move the pledget 18 into the biopsy needle 16. When the adaptor
lumen has been blocked by the hydrated pledget 18 which has swelled
within the adaptor, injection of additional fluid will push the
pledget through the tapered section 42 of the adaptor. If the
adaptor lumen has not been entirely blocked by the pledget 18, the
venturi effect will help draw the pledget through the tapered
section 42 of the adaptor. After the pledget 18 is moved to the
biopsy needle 16, the pledget 18 is then delivered from the needle
16 to the biopsy tract by rapid injection of additional fluid by
the syringe 14. The hydrated pledget 18 quickly expands upon
delivery to fill the available space in the biopsy tract to
facilitate hemostasis and provide localized compression.
[0057] The absorbable sponge material of the present invention can
be shaped into the required size by conventional means. Pledgets
may be cut with a punch or a stencil or template and knife. Once
hydrated, the pledget 18 can be easily compressed to fit into a
lumen having a smaller cross sectional area than the original cross
sectional area of the pledget. Additionally, the kneading of the
hydrated pledget 18 during delivery encourages air trapped within
the absorbable sponge to be expelled and replaced with fluid,
allowing rapid expansion upon delivery.
[0058] When delivering a pledget 118 of absorbable sponge material,
it is important to deliver a desired amount of the sponge material
using a minimum amount of fluid.
[0059] Pledgets 118 with increased cross sectional area proximal
ends may be prepared in a variety of manners. For example, if a
pledget 118 is prepared from a sheet of sponge material, the
increased proximal mass can be achieved by cutting the pledget with
an enlarged proximal end. Alternatively, the pledget 118 may be
formed by folding, rolling, compressing, or otherwise manipulating
the sponge material to the desired shape. The proximal pledget mass
may also be increased by adding separate pieces of material to the
proximal end of the pledget. This additional material may be
layered, wrapped, coiled or attached to the pledget in any other
manner. The pledgets may also be formed by molding, bump extruding,
dipping, or the like. The larger cross sectional area proximal end
is generally about 1.2 to 4 times the cross sectional area of the
distal end. In addition, the proximal end with the larger cross
section area preferably extends along about 1/8 to 3/4 of the total
pledget length.
[0060] The pledget 118 illustrated in FIG. 5 has been formed by
cutting a strip of material from an absorbable sponge sheet 20 with
the aid of the template 122 as illustrated in FIG. 6. After the
strip is cut, the proximal end of the strip is then folded back
onto itself to form a pledget 118 with an increased cross sectional
area and material mass at a proximal end. One example of a
preferred embodiment of a pledget for delivery down a 20 gauge
biopsy needle or cannula has a size of approximately
0.1.times.1.5.times.0.06 inches and is folded as illustrated in
FIG. 5 to an overall length of about 0.9 inches. Placing this
pledget 118 in an adaptor 112 having a largest internal diameter of
0.125 inches allows the pledget to be delivered to a 20 gauge or
larger biopsy needle. Other common biopsy procedures use an 18
gauge or larger biopsy needle through a slightly larger guide
cannula and would receive a somewhat larger pledget. After taking a
core sample and removing the biopsy needle from the cannula guide,
a pledget 118 maybe delivered through the cannula the biopsy site.
The pledget 118 for use in the system employing an 18 gauge or
larger biopsy needle may be formed from a strip which is
approximately 0.11-0.12 inches wide by about 3.125 inches long with
a thickness of about 0.06 inches and folded to an overall length of
about 2.2 inches. This pledget having a 28 which is attached to the
distal end of the adaptor.
[0061] As described above, the pledget may be delivered to the
biopsy tract by holding the biopsy needle or cannula 16 stationary
and injecting the pledget through the biopsy needle. If additional
pledgets are to be delivered, the biopsy needle 16 is withdrawn a
distance sufficient to accommodate an additional pledget and the
additional pledget is then injected.
[0062] An alternative method of delivering the pledget into the
biopsy tract includes withdrawing the biopsy needle or cannula 16
during delivery of the pledget 18 to deliver the pledget in an
elongated trail which follows the biopsy tract. Placing the
absorbable sponge material in a trail which fills the entire biopsy
tract provides the added benefit of providing hemostasis along the
entire biopsy tract. This is particularly helpful for stopping the
bleeding of biopsy tracts in organs which tend to have excessive
bleeding such as the liver, kidney, spleen, and other vascular
organs.
[0063] In order to achieve a trail of absorbable sponge material in
the biopsy tract, one method of the present invention involves the
delivery of the pledget into the biopsy needle by a predetermined
amount of fluid. The biopsy needle is then withdrawn at a velocity
V while the pledget material is ejected from the biopsy needle at a
velocity E with respect to the biopsy needle. The velocity V at
which the biopsy needle is withdrawn is equal to or less than the
velocity E at which the absorbable sponge material is delivered.
The control of injection of fluid and withdrawal of the needle to
achieve the desired trail of absorbable sponge material in the
biopsy tract maybe controlled with an injection controlling
device.
[0064] According to an alternative embodiment as illustrated in
FIG. 7, the adaptor may be used to deliver the pledget into the
biopsy needle 16 and then the adaptor is removed from the biopsy
needle. A plunger or stylet 80 which is generally provided with the
biopsy needle 16 for inserting the biopsy needle is then used to
deliver the pledget from the biopsy needle. As shown in FIG. 7, the
biopsy needle extends through the tissue 84 and into the organ 86
for removal of a core of tissue. After biopsy, the pledget is
injected into the needle 16 and the plunger 80 is placed within the
biopsy needle so that a distal end of the plunger abuts the
proximal end of the pledget 118. The plunger 80 is then held
stationary while the biopsy needle 16 is withdrawn from the biopsy
site. The plunger 80 causes the pledget 118 to be delivered in a
trail 88 which fills the biopsy tract. The trail 88 preferably
extends along the entire biopsy tract to or past a surface of the
organ 86. The delivery of the trail 88 of absorbable sponge
material provides an advantage over the delivery of discrete blobs
of material because the trail is able to provide hemostasis along
the entire tract. In contrast, if a blob of absorbable sponge
material is delivered within the tract at a depth of 1-2 cm from
the surface of the organs, this 1-2 cm of biopsy tract may continue
to bleed significantly.
[0065] As an alternative to delivery of the pledget as a trail, the
pledget may be delivered as a plug. To deliver a plug the plunger
80 is advanced into the needle 16 pushing the pledget out of the
distal end of the needle while the needle is held stationary. A
combination of delivery of plugs and trails may also be used. The
pledget material may be delivered entirely within a single
anatomical structure or may cross two or more anatomical structures
such as an organ, surrounding tissue and facial layer.
[0066] In some instances it may be desirable to deliver multiple
pledgets in spaced apart positions along the biopsy tract,
particularly for a long biopsy tract. For delivery of additional
pledgets, the biopsy needle 16 is retracted a distance sufficient
to provide a space to accommodate an additional pledget 18 and the
injection procedure described above is repeated for the additional
pledget(s). For a particularly large biopsy site or cavity,
additional pledgets 18 may be injected beside an initially injected
pledget until the cavity is filled.
[0067] Although biopsy is most commonly performed by biopsy needle,
biopsy may also be performed through other cannulas, such as
catheters, long needles, endoscopes, or the like. The treatment
procedure according to the present invention can be used for
facilitating hemostasis of puncture wounds through different types
of cannulas including needles, catheters, endoscopes, and the like.
In addition, the treatment procedure and systems according to the
present invention may be used to deliver absorbable or
non-absorbable sponge for other therapies. For example, sponge may
be delivered for cosmetic or reconstructive bulking or for
temporary or permanent intravascular embolization.
[0068] In addition to the contrasting agent, the absorbable sponge
pledget 18 may be used to deliver a beneficial agent, such as,
thrombin, radiation treatment, or the like. The pledget can also be
used to deliver therapeutic agents, such as radioactive isotopes
for localized treatment of tumors, anti-cancer agents,
anti-metastatic agents, and the like. Examples of anti-cancer
agents include 5-fluorouracil, cisplatin, prednisone, and others
described in U.S. Pat. No. 4,619,913 which is incorporated herein
by reference. The absorbable sponge pledget 18 may be presoaked
with the beneficial agent for delivery to the biopsy tract.
Alternatively, the pledget 18 may be hydrated with the beneficial
liquid agent or the agent may be delivered to the pledget after the
pledget is placed within the biopsy tract.
[0069] A pledget formed of inventive absorbable sponge material
preferably will be absorbed by the body within 1 to 6 weeks.
However, the pledget material may be designed to provide different
rates of absorption. If the contrasting agent employed is also
absorbable, the contrasting agent should be absorbed at
approximately the same rate as the sponge material. Where the
contrasting agent is non-absorbable, it will remain at the
site.
[0070] While the invention has been described in detail with
reference to the preferred embodiments thereof, it will be apparent
to one skilled in the art that various changes and modifications
can be made and equivalents employed, without departing from the
present invention.
* * * * *