U.S. patent application number 10/666204 was filed with the patent office on 2005-03-17 for circular stapler buttress.
Invention is credited to Bauman, Ann M., Broyles, Stuart E., Crawley, Jerald M., Daugherty, John R., Pih, Norman.
Application Number | 20050059997 10/666204 |
Document ID | / |
Family ID | 34274704 |
Filed Date | 2005-03-17 |
United States Patent
Application |
20050059997 |
Kind Code |
A1 |
Bauman, Ann M. ; et
al. |
March 17, 2005 |
Circular stapler buttress
Abstract
A buttress for use with circular surgical staplers that does not
require adhesive to securely fasten the buttress to the stapler and
that self-aligns onto the stapler. Following cutting and stapling
by the circular stapler, the buttress has an adaptive opening
through its central region with a diameter smaller than the outer
diameter of the stapler anvil. Because of relief features built
into the buttress, the stapler anvil may be pulled through the
buttress material without causing permanent alteration to the
buttress. These relief features may be provided regardless of
whether the buttress is made of inelastic or elastic materials. The
buttress is generally circular in shape with an outer diameter
sized to coincide with the outer diameter of the stapler body
staple compression surface and the outer diameter of the anvil
compression surface of a circular stapler with which it is used.
Prior to surgical use, the buttress is provided with a generally
circular hole in the central region that is sized to closely fit
the central shaft of a circular stapler with which it is used.
Inventors: |
Bauman, Ann M.; (Flagstaff,
AZ) ; Broyles, Stuart E.; (Flagstaff, AZ) ;
Crawley, Jerald M.; (Flagstaff, AZ) ; Daugherty, John
R.; (Flagstaff, AZ) ; Pih, Norman; (Flagstaff,
AZ) |
Correspondence
Address: |
GORE ENTERPRISE HOLDINGS, INC.
551 PAPER MILL ROAD
P. O. BOX 9206
NEWARK
DE
19714-9206
US
|
Family ID: |
34274704 |
Appl. No.: |
10/666204 |
Filed: |
September 17, 2003 |
Current U.S.
Class: |
606/219 |
Current CPC
Class: |
A61B 2017/07257
20130101; A61B 17/115 20130101; A61B 17/07292 20130101; A61B 17/072
20130101 |
Class at
Publication: |
606/219 |
International
Class: |
A61B 017/08 |
Claims
We claim:
1. A reinforcement device for use with a circular stapler that is
adapted to create and seal a surgical opening in a patient
comprising: a buttress adapted for mounting on the circular
stapler, the stapler having an anvil that is larger in diameter
than the surgical opening that is created by the stapler, wherein
following stapling with the stapler, the buttress reinforces the
surgical opening created by the stapler in the patient; wherein the
buttress includes at least one adaptive opening created by the
circular stapler which corresponds to the surgical opening in the
patient, said adaptive opening when circular having a diameter
smaller than the diameter of the anvil, and wherein the adaptive
opening in the buttress allows the anvil to be removed therethrough
without causing permanent alteration to the buttress.
2. The reinforcement device of claim 1 wherein the permanent
alteration includes tearing.
3. The reinforcement device of claim 1 wherein the permanent
alteration includes permanent deformation to the adaptive opening
created by the stapler.
4. The reinforcement device of claim 1 wherein the buttress has
slits along a periphery of the adaptive opening.
5. The reinforcement device of claim 1 wherein the buttress is
corrugated along a periphery of the adaptive opening.
6. The reinforcement device of claim 1 wherein the buttress
self-aligns on the stapler.
7. The reinforcement device of claim 6 wherein the self-aligned
buttress is retained on the stapler without use of an adhesive.
8. The reinforcement device of claim 6 wherein the buttress
self-aligns with respect to a central shaft on the stapler.
9. The reinforcement device of claim 6 wherein the buttress
self-aligns on the stapler by conforming to an edge delimiting an
outer diameter of the stapler.
10. The reinforcement device of claim 1 wherein the reinforcement
buttress comprises a bioabsorbable material.
11. The reinforcement device of claim 10, wherein the bioabsorbable
material comprises a copolymer of poly(glycolide:trimethylene
carbonate).
12. The reinforcement device of claim 1 wherein the buttress
includes a filler material.
13. The reinforcement device of claim 12 wherein the filler
material comprises a therapeutic agent.
14. The reinforcement device of claim 12 wherein the filler
material comprises a bioactive agent.
15. The reinforcement device of claim 1 wherein the buttress
comprises an essentially inelastic material.
16. The reinforcement device of claim 1 wherein the buttress
comprises an essentially elastic material.
17. The reinforcement device of claim 1 wherein the buttress
comprises at least one polymeric material.
18. The reinforcement device of claim 17 wherein the polymeric
material comprises polytetrafluoroethylene.
19. The reinforcement device of claim 18 wherein the
polytetrafluoroethylene is porous expanded
polytetrafluoroethylene.
20. The reinforcement device of claim 1 wherein the circular
stapler is adapted to create an anastomotic junction between body
tissue; and the buttress augments resistance to radial distension
at the anastomotic junction.
21. The reinforcement device of claim 1 wherein the device has a
reinforced central region that provides added rigidity to the
central region.
22. The reinforcement device of claim 21 wherein the central region
has greater thickness than other regions of the device.
23. The reinforcement device of claim 21 wherein the central region
has denser material than other regions of the device.
24. A reinforcement device for use with a circular stapler that is
adapted to create a substantially circular hole in a patient, said
circular stapler having a central shaft, comprising: a buttress
adapted for mounting on the central shaft of the circular stapler;
wherein the buttress self-aligns around the central shaft; and
wherein the buttress reinforces the hole created by the stapler in
the patient.
25. The reinforcement device of claim 24 wherein the stapler
includes an anvil that is larger in diameter than the circular hole
that is created by the stapler.
26. The reinforcement device of claim 24 wherein the buttress
comprises an essentially elastic material.
27. The reinforcement device of claim 24 wherein the buttress
comprises an essentially inelastic material.
28. The reinforcement device of claim 24 wherein the buttress
comprises at least one polymeric material.
29. The reinforcement device of claim 28 wherein the polymeric
material comprises polytetrafluoroethylene.
30. The reinforcement device of claim 29 wherein the
polytetrafluoroethylene is porous expanded
polytetrafluoroethylene.
31. The reinforcement device of claim 24 wherein the buttress
comprises a bioabsorbable material.
32. The reinforcement device of claim 31, wherein the bioabsorbable
material comprises a copolymer of poly(glycolide:trimethylene
carbonate).
33. The reinforcement device of claim 24 wherein the buttress
includes a filler.
34. The reinforcement device of claim 33 wherein the filler
includes a therapeutic agent.
35. The reinforcement device of claim 33 wherein the filler
includes a bioactive agent.
36. A reinforcement device comprising: a circular stapler that is
adapted to create a substantially circular hole in a patient, said
circular stapler having a stapler anvil compression surface outer
diameter and a stapler body compression surface outer diameter; a
first buttress adapted to self align onto the stapler anvil
compression surface outer diameter and the stapler body compression
surface outer diameter; a second buttress adapted to self align
onto the stapler body compression surface outer diameter; and
wherein the first and second buttresses reinforce the hole created
by the stapler in the patient when staples are applied.
37. The reinforcement device of claim 36 wherein the stapler
includes an anvil that is larger in diameter than the circular hole
that is created by the stapler.
38. The reinforcement device of claim 36 wherein the buttress
comprises an essentially elastic material.
39. The reinforcement device of claim 36 wherein the buttress
comprises an essentially inelastic material.
40. The reinforcement device of claim 36 wherein the buttress
comprises at least one polymeric material.
41. The reinforcement device of claim 40 wherein the polymeric
material comprises polytetrafluoroethylene.
42. The reinforcement device of claim 41 wherein the
polytetrafluoroethylene is porous expanded
polytetrafluoroethylene.
43. The reinforcement device of claim 36 wherein the buttress
comprises a bioabsorbable material.
44. The reinforcement device of claim 43, wherein the bioabsorbable
material comprises a copolymer of poly(glycolide:trimethylene
carbonate).
45. The reinforcement device of claim 36 wherein the buttress
includes a filler.
46. The reinforcement device of claim 45 wherein the filler
includes a therapeutic agent.
47. The reinforcement device of claim 45 wherein the filler
includes a bioactive agent.
48. A reinforcement device comprising: a circular stapler that is
adapted to create a substantially circular hole in a patient, said
circular stapler having a stapler anvil compression surface outer
diameter at least one buttress adapted to self align onto the
stapler anvil compression surface outer diameter; and wherein the
buttress reinforces the hole created by the stapler in the patient
when staples are applied.
49. The reinforcement device of claim 48 wherein the stapler
includes an anvil that is larger in diameter than the circular hole
that is created by the stapler.
50. The reinforcement device of claim 48 wherein the buttress
comprises an essentially elastic material.
51. The reinforcement device of claim 48 wherein the buttress
comprises an essentially inelastic material.
52. The reinforcement device of claim 48 wherein the buttress
comprises at least one polymeric material.
53. The reinforcement device of claim 52 wherein the polymeric
material comprises polytetrafluoroethylene.
54. The reinforcement device of claim 53 wherein the
polytetrafluoroethylene is porous expanded
polytetrafluoroethylene.
55. The reinforcement device of claim 48 wherein the buttress
comprises a bioabsorbable material.
56. The reinforcement device of claim 55, wherein the bioabsorbable
material comprises a copolymer of poly(glycolide:trimethylene
carbonate).
57. The reinforcement device of claim 48 wherein the buttress
includes a filler.
58. The reinforcement device of claim 57 wherein the filler
includes a therapeutic agent.
59. The reinforcement device of claim 57 wherein the filler
includes a bioactive agent.
60. A reinforcement device comprising: a circular stapler that is
adapted to create a substantially circular hole in a patient, said
circular stapler having a stapler body compression surface outer
diameter at least one buttress adapted to self align onto the
stapler body compression surface outer diameter; wherein the
buttress reinforces the hole created by the stapler in the patient
when staples are applied.
61. The reinforcement device of claim 60 wherein the stapler
includes an anvil that is larger in diameter than the circular hole
that is created by the stapler.
62. The reinforcement device of claim 60 wherein the buttress
comprises an essentially elastic material.
63. The reinforcement device of claim 60 wherein the buttress
comprises an essentially inelastic material.
64. The reinforcement device of claim 60 wherein the buttress
comprises at least one polymeric material.
65. The reinforcement device of claim 64 wherein the polymeric
material comprises polytetrafluoroethylene.
66. The reinforcement device of claim 65 wherein the
polytetrafluoroethylene is porous expanded
polytetrafluoroethylene.
67. The reinforcement device of claim 60 wherein the buttress
comprises a bioabsorbable material.
68. The reinforcement device of claim 67, wherein the bioabsorbable
material comprises a copolymer of poly(glycolide:trimethylene
carbonate).
69. The reinforcement device of claim 60 wherein the buttress
includes a filler.
70. The reinforcement device of claim 69 wherein the filler
includes a therapeutic agent.
71. The reinforcement device of claim 69 wherein the filler
includes a bioactive agent.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to the field of surgical
buttresses.
BACKGROUND OF THE INVENTION
[0002] A circular stapler is one device that can be used in
surgical applications for the joining of body tissue. In the area
of surgical anastomotic stapling, it can be used for joining pieces
of tissue in a manner such that a continuous pathway, lumen, or
surgical opening, is formed after the tissue is stapled together.
This lumen is formed when a circle of staples is used to join two
pieces of tissue after which the tissue interior to the innermost
circle of staples is cut out by a concentric circular retractable
blade. Retraction of the circular stapler removes the cut tissue to
form a lumen. An example of a circular stapler is given in U.S.
Pat. No. 5,104,025 to Main et al. Other devices and methods can
also be used to produce anastomoses.
[0003] When used in surgery for colorectal disorders the circular
stapler is used to reform the colon into a continuous lumen after a
section is removed for treatment of the disease state. Concerns
about leakage of the colon contents into the peritoneal cavity from
the anastomosis site are prevalent during this type of surgery. A
complete seal between the pieces of tissue that are joined is
desirable to prevent leakage. Another concern in colon resections
is reduction of the lumen diameter after surgery. This reduction in
diameter would result in the restriction of the passage of
biological material.
[0004] Using a stapler that forms a lumen with a diameter close to
that of the preoperative healthy colon is desirable to prevent
these flow restrictions. Typically the circle of staples formed is
between 2-4 cm in diameter and is made from 20 to 40 small,
metallic staples. Due in part to the presence of these metallic
staples, another concern in tissue resection is tearing of the
tissue at the anastomosis site.
[0005] Modifications to circular staplers as well as the
development of other devices have been described to address the
concerns that may occur during stapling of body tissue and the
formation of a tissue anastomosis. A device used to create an
anastomosis without staples is described in U.S. Pat. No. 5,222,963
to Brinkerhoff et al. and U.S. Pat. No. 5,250,058 to Miller et al.
This device uses a tissue coupler made from a bioabsorbable
polymer. A concern in using this device is the risk of tissue
separation at the anastomosis site after the polymer has been
absorbed by the body. A similar concern is shared for the device
described in U.S. Pat. No. 5,346,501 to Regula et al., as it also
uses only a bioabsorbable material for the formation of the
anastomosis.
[0006] To alleviate the concern about tissue separation after the
absorption of a bioabsorbable material, non-absorbable
biocompatible metal staples can be used to form the anastomosis.
However, leakage and/or tearing at the site where the tissue is
joined are concerns when only metal staples are used. In order to
prevent leakage or tearing, supporting buttresses constructed of
both non-bioabsorbable and bioabsorbable materials for use with
surgical staplers have been described in various publications. U.S.
Pat. No. 6,503,257 to Grant et al. teaches a method for using an
adhesive to releasably attach a buttress construct to a surgical
stapling instrument. This buttress addresses both the leakage and
tearing concerns that occur during tissue stapling. The use of
metal staples provides for the long-term joining of the tissue.
However, the buttress must be carefully aligned onto the stapling
instrument and a suitable adhesive must be used on the surfaces of
both the buttress and the stapling instrument to secure the
buttress to the stapling instrument. Further, withdrawing the anvil
part of the stapler through the buttress may be difficult, as the
inner diameter of the buttress is smaller than the outer diameter
of the stapler anvil.
SUMMARY OF THE INVENTION
[0007] The present invention is in the form of a buttress
reinforcement device for use with circular surgical staplers that
does not require an adhesive substance between the buttress and
stapler to securely fasten the buttress to the stapler. Preferably,
the buttress self aligns onto the stapler. In a preferred
embodiment, when used with a circular surgical stapler, a hole is
cut in the central region of the buttress by the stapler's circular
cutting blade. The diameter of the hole formed in the buttress by
the stapler's circular cutting blade is smaller than the outer
diameter of the stapler's anvil. Relief features built into the
buttress allow the stapler anvil to pull through the hole created
in the buttress by the stapler's circular cutting blade without
causing substantial permanent alteration to the buttress. These
relief features can be provided regardless of whether the buttress
is made of inelastic or elastic materials.
[0008] The buttress can be generally circular in shape with an
outer diameter sized to coincide with the outer diameter of the
stapler body staple compression surface and the outer diameter of
the anvil compression surface of a circular stapler with which it
is used. Alternatively, the buttress material may be formed into
other non-circular geometric shapes (e.g. octagons). Also, the
buttress material can be sized to be larger than or the same as the
outer diameter of the stapler body staple compression surface and
the outer diameter of the anvil compression surface of a circular
stapler with which it is used in order to allow for self-alignment.
This self-alignment insures that the buttress is aligned to
coincide with and cover the pattern of staples ejected from the
stapler. The buttress may have a generally circular opening in its
central region that is sized to closely fit the central shaft of a
circular stapler with which it is used. Alternatively, the buttress
may have slits or other openings cut in its central region to allow
for fitting the buttress onto the central shaft of a circular
stapler while retaining the self-alignment feature. In a preferred
embodiment, the central region of the buttress is that area which
is cut away from the buttress by the action of the stapler cutting
blade. In addition to the central opening, the buttress may have a
slit or other opening reaching from the central opening to the
outer diameter of the buttress. This feature would allow the
buttress to be placed onto the central shaft of a circular stapler
even when the stapler anvil was already attached to the stapler
body through the central shaft.
[0009] In one embodiment, the buttress can have a retaining ring,
disk, or similar device within or around its central region with a
central opening. This retaining ring, disk, or similar device can
be used to aid in the retention of the buttress onto the central
shaft of the circular stapler without requiring the use of an
adhesive substance between the central shaft of the stapler and the
buttress construct. The retention of the buttress onto the circular
stapler allows for movement, removal, or repositioning of the
circular stapler during operation without loss or displacement of
the buttress from the stapler.
[0010] A preferred bioabsorbable buttress is fabricated from a
copolymer of poly(glycolide:trimethylene carbonate). The
copolymer's polyglycolide component is commonly abbreviated as PGA
for poly(glycolic acid), the chemical byproduct to which it
degrades after hydrolysis. The poly(trimethylene carbonate)
component is commonly abbreviated as TMC, with the copolymer itself
typically referred to as PGA:TMC and accompanied with relative
percentage composition by weight. A preferred embodiment of the
buttress is made from a bioabsobable ABA triblock copolymer of 67%
PGA:33% TMC (w/w), formed into a non-woven web as taught by Hayes
in U.S. Pat. Nos. 6,165,217 and 6,309,423. Other fabrications,
processes, and polymers can alternatively be used to produce an
elastic bioabsorbable buttress, such as using the polymers
described by Bezwada in U.S. Pat. Nos. 5,468,253 and 5,713,920.
While the primary constituent polymer can be alternatively blended
with other polymers or active or inactive agents prior to
fabrication, the resulting buttress can be imbibed, coated, or
otherwise loaded with therapeutic or other either bioactive or
bioinactive materials.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIGS. 1A and 1B are perspective views of the bioabsorbable
circular stapler buttresses mounted on a typical circular stapler
and showing how the anvil portion of the circular stapler can be
separated from the body of the stapler.
[0012] FIGS. 2A-2D are cross sectional views of colon undergoing
resection using the buttresses of the present invention.
[0013] FIG. 2E is a perspective view of a longitudinal section of a
colon undergoing resection using buttress of the present invention,
that has been cut and stapled by a circular stapler.
[0014] FIGS. 3A-3F show top views of various embodiments of the
buttress.
[0015] FIGS. 3G, 3H, 3J and 3K show perspective views of the
buttress having various corrugations.
[0016] FIGS. 4A-4C show side views of three alternate embodiments
of the buttress with varying thicknesses and densities.
[0017] FIGS. 5A-5E show top views of elastic and inelastic
buttresses prior to and following central region cut out by the
generally circular concentric cutting blade of a circular stapler
and following removal of the anvil portion of a circular stapler
through the central region hole.
[0018] FIG. 5G shows a cross sectional view of an inelastic
buttress following removal of the anvil portion of a circular
stapler though the hole created by the generally circular
concentric cutting blade of a circular stapler.
[0019] FIG. 6A shows a perspective view of a buttress allowing for
self-alignment on the central shaft of a circular stapler.
[0020] FIG. 6B shows a cross sectional view of a buttress allowing
for self-alignment on the central shaft of a circular stapler.
[0021] FIG. 6C shows a perspective view of a buttress allowing for
self-alignment on the outer diameter of a stapler anvil head or
stapler body compression surface.
[0022] FIG. 6D shows a cross sectional view of a buttress allowing
for self-alignment on the outer diameter of a stapler anvil head or
stapler body compression surface.
DETAILED DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1A is a perspective view of a typical circular surgical
stapler 10 with two stapler buttresses 12 mounted on the central
shaft 14 of the stapler. The stapler has an anvil head 16 with a
staple compression surface 18. The anvil head 16 is removably
attached to the stapler body 22 via the central shaft 14 as shown
in FIG. 1B. The stapler body also has a compression surface 20
through which staples are ejected. The central openings 15 in the
buttresses 12 are sized to closely fit over the central shaft 14 so
that the buttresses self-align onto the shaft. The central openings
15 in the buttresses 12 may be generally circular, slits or of any
other geometric shape. Because of the size and shape of the central
openings 15, the buttresses 12 are self-aligned and concentric to
the cutting mechanism and stapler compression surfaces of the
circular stapler. Each buttress 12 further has a member 13 that
aids in attaching the buttresses 12 to the central shaft 14 of the
stapler without the use of adhesive substance between the central
shaft 14 of the stapler and the buttresses 12. The buttresses 12
can be placed onto the central shaft 14 of the circular stapler 10
when the stapler anvil 16 is separated from the stapler body 22 as
shown in FIG. 1B. Alternatively, a buttress 12 with a slit or other
opening reaching from the central opening to the outer diameter of
the buttress can be placed onto the central shaft 14 of a circular
stapler 10 when the stapler anvil 16 is connected to the stapler
body 22 as shown in FIG. 1A.
[0024] FIGS. 2A-2E show circular stapler buttresses 12 in use
during, for example, a typical colon resection. FIG. 2A shows the
stapler anvil head 16 and a buttress 12 placed inside the proximal
end of a colon section 24, wherein proximal is defined as being
closer to the heart of the patient being operated upon. An end of
the central shaft 14 is protruding through a hole 29 formed in the
colon tissue wall 25. The stapler body 22 and another buttress 12
are placed transanally inside a distal segment of the colon 26,
wherein distal is defined as being farther from the heart of the
patient being operated upon. Another end of the central tubular
shaft 14 protrudes through a hole 31 formed in the distal colon
tissue wall 27.
[0025] FIG. 2B shows the central shaft 14 with the anvil head 16
now joined to the stapler body 22. One buttress 12 is located
between anvil compression surface 18 and the proximal colon tissue
wall 25. Another buttress 12 is located between the body
compression surface 20 and the distal colon tissue wall 27. The
circular stapler 10 can be operated so as to pull the anvil head 16
towards the stapler body 22 so that the anvil head 16 and stapler
body 22 are moved to within close opposition of each other.
[0026] FIG. 2C shows the anvil head 16 and stapler body 22 in close
proximity to each other in a position where the staples can be
ejected through the compression surface on the stapler body 20 to
pierce through the opposing tissue walls of both the proximal 25
and distal 27 colon wall sections and also though the buttresses 12
placed internally within each colon section. The staples upon
ejection are bent as they impact on the compression surface 18 of
the anvil head 16 and compression surface 20 of the stapler body
22, to form a shape designed to tightly hold the colon sections
together. The staples pierce through the colon tissue walls 25, 27
and the buttresses 12 that are placed internally on each side of
the joined colon sections. FIG. 2C also shows a generally circular
concentric cutting blade 33 which can be actuated by the stapler
operator when the stapler anvil head 16 has been moved to a
position of close opposition to the stapler body 22. The generally
circular concentric cutting blade 33 in the circular stapler body
22 moves upon actuation by an operator from a retracted position to
an extended position to cut through the opposing walls of both the
proximal 25 and distal 27 colon sections as well as the buttresses
12 placed internally in each colon section after the staples have
been positioned and ejected. The generally circular concentric
cutting blade cuts through the tissue adjacent to the inner
diameter of the innermost row of staples to allow a continuous
lumen to form between the now-joined colon sections. Therefore an
anastomotic junction is created in the body tissue. After the
anastomotic junction has been formed, the stapler is operated so
that the stapler anvil head 16 is moved away from the staple body
22 to release the tissue compressed between the compression
surfaces of the anvil head 18 and stapler body 20. The circular
stapler 10 is withdrawn transanally carrying with it the sections
of colon tissue and central regions of the buttresses 12, which
were cut by the generally circular stapler blade.
[0027] FIGS. 2D and 2E show the proximal 24 and distal 26 colon
sections now joined together. The staples 35, which are located
circumferentially around the colon tissue, are held securely in
place by means of the colon tissue walls, 25, 27 which have been
reinforced with the buttresses 12. The buttresses 12 provide
circumferential support to the anastomotic junction in addition to
enhancing sealing between the staples and tissue. These buttresses
12 may therefore augment resistance to radial distension at the
anastomotic junction.
[0028] The above description relates to use of the buttresses 12 of
the present invention in forming a tissue anastomosis in a colon
resection. It is anticipated that buttresses of this design could
be used for other gastro-intestinal applications, vascular
applications and other applications in the human or animal body.
Additionally, the above description describes the buttresses 12
both being placed internally within the colon segments. In an
alternative use, a buttress 12 could be placed external to the
colon segments. Further, buttresses 12 could be placed internally
within each colon segment while another buttress could be placed
externally between the colon segments. In another use, one buttress
could be placed internally within one colon segment while another
buttress could be placed externally between the colon segments. The
number of buttresses 12 used and placement of the buttresses 12 in
and around the relevant tissue sections is left to the surgeon.
[0029] The buttress 12 of the present invention may be fabricated
from either bioabsorbable or non-absorbable biocompatible
materials. A preferred embodiment for the buttress of the present
invention is a bioabsorbable ABA triblock copolymer of 67%
PGA:33%TMC (w/w) formed into a self-cohering non-woven web as
generally taught by Hayes in U.S. Pat. Nos. 6,165,217 and
6,309,423. Alternatively, this web or other buttress constructs may
be fabricated from other biocompatible bioabsorbable polymers and
copolymers composed from varying amounts of one or more of the
following monomer examples: glycolide, d,l-lactide, I-lactide,
d-lactide, p-dioxanone (1,4-dioxane-2-one), trimethylene carbonate
(1,3-dioxane-2-one), .epsilon.-caprolactone, gamma.-butyrolactone,
delta.-valerolactone, 1,4-dioxepan-2-one, and 1,5-dioxepan-2-one.
Other polymeric constituents of a bioabsorbable copolymer may
include polyethylene glycol, polypropylene glycol, amino acids,
anhydrides, orthoesters, phosphazines, amides, urethanes, and
phosphoesters. Alternative copolymers may possess, in whole or in
part, block, segmented, random, alternating, or statistical
polymeric construction characteristics. Animal derived products
such as elastin, collagen or decellularized submucosa, either
absorbable (e.g. enzymatically degraded within the body) or
rendered non-absorbable through chemical treatment (e.g.,
glutaraldehyde cross-linked bovine pericardium or porcine
pericardium), may alternatively be utilized to provide a buttress
construct. Various non-absorbable polymers may be utilized for
buttress construction include but are not limited to
polytetrafluoroethylene, fluorinated ethylene propylene (FEP),
fluoroelastomers, polyurethanes, polyesters (e.g. polyethylene
terephthalate), polyacrylamide, polyacetate, polypropylene,
polydimethylsiloxane, and nylon. Of these, porous expanded
polytetrafluoroethylene (ePTFE), generally made as taught by U.S.
Pat. No. 3,953,566 to Gore, may provide a preferred non-absorbable
buttress.
[0030] A preferred method of forming the buttress 12 using a
bioabsorbable material is using a piece of 67%/33% PGA:TMC (w/w)
that has been formed into a self-cohering non woven web into a
thickness of approximately 0.25 mm following methods as generally
taught by Hayes in U.S. Pat. Nos. 6,165,217 and 6,309,423. This
piece of self-cohering non woven web is cut, for example, by a
laser into a generally circular shape with an outer diameter made
to coincide with the compression surface outer diameters for the
anvil 18 and body 20 of a particular circular stapler. A variety of
other cutting methods, such as die cutting, can be alternatively
used. Due to the porous construction of the self-cohering non-woven
web, various bioactive agents and carrier materials can be
introduced into the porous interfiber interstices of the web or
coated onto the fiber strands. Bioactive agents in this context
refers to growth factors, chemotactic factors, morphogens,
pharmaceuticals or drugs, catalysts, proteins, peptides or other
biologically active molecules or genetically altered or native
state living cells of autogenic, allogenic, xenogenic or
recombinant origin that induce an intended biological response.
Such substances include, but are not limited to antibiotics,
organic or inorganic antimicrobials, healing factors, blood
clotting agents, anticoagulants, antithrombotics, antispasmodics,
immunosuppressives, antacids, acid inhibitors, and ulcer treating
agents. Other fillers can include radiopaque substances to enhance
visualization. Bioactive agents and fillers could be used with
other porous and non-porous constructions for other bioabsorbable
as well as non-absorbable materials.
[0031] FIGS. 3A-3E show top views of buttresses 12 with various
relief features cut into them. These relief features form "adaptive
openings" in the reinforcement material. These "adaptive openings"
allow a larger diameter anvil 16 of a circular surgical stapler 10
to be pulled through the smaller diameter opening created by the
cutting blade of the circular stapler without causing substantial
permanent alteration to the reinforcement material. The relief
features are preferably formed by laser cutting, although they
could be made by a variety of other methods such as by use of a
cutting die. The relief features are sized and placed so that some
part of them remain on the portion of the buttress 12 that remains
in the patient after the cutting action of the blade of a circular
stapler. As will be further described, an adaptive opening may also
be provided by making the perimeter of the adaptive opening
corrugated, thereby providing extra material along the perimeter
and accordingly increasing its flexibility in order to allow the
stapler anvil to be withdrawn through the adaptive opening.
[0032] FIG. 3A shows the top view of a buttress 12 with twelve
equally spaced linear radial cuts 32 emanating from the area of a
central opening 30.
[0033] FIG. 3B shows the top view of a buttress 12 with four
equally spaced linear cuts or slits 34 in a radial spoke type
pattern emanating from the area of a central opening 30.
[0034] FIG. 3C shows the top view of a buttress 12 with four
equally spaced linear cuts or slits 34 surrounding a central
opening 30 as in FIG. 3B but with the addition of four radial cuts
or slits 36 originating from the perimeter of the buttress 12.
[0035] FIG. 3D demonstrates that the relief features can be other
than straight lines. FIG. 3D shows the top view of a buttress 12
that has serpentine shaped relief features 48 emanating from the
area of a central opening 30.
[0036] FIG. 3E demonstrates that other geometric figures could
provide similar function to the operation of the buttress, showing
the top view of a buttress 12 with a series of generally triangular
shapes 40 that are arranged radially around a central opening 30.
The bases of the triangular shapes 42 are placed to coincide with
the outside diameter of the generally circular concentric cutting
blade of the selected circular stapler.
[0037] FIG. 3F shows a top view of a buttress 12 having a slit 51
through the entire width. It is apparent that, in addition to
providing for an adaptive opening, the slit 51 allows the buttress
12 to be fitted over the central shaft 14 of the stapler without
necessitating the prior removal of the anvil 16 from the stapler
body 22.
[0038] FIG. 3G is a perspective view of a buttress 12 showing an
embodiment wherein the adaptive opening results from corrugations
54. FIG. 3G has an inner edge 50 and an outer edge 52 with
corrugations 54 that are formed between the inner and outer edges
50, 52. These corrugations may be made, for example, by
transversely cutting a short segment from a length of tubular
material, and deforming the resulting ring-shaped segment by
bending one edge inwardly to cause the inner hole whereby the extra
material results in corrugations. Alternatively, a mold could be
used to form the corrugations.
[0039] FIG. 3H is a perspective view of a buttress 12 showing an
embodiment wherein the adaptive opening results from corrugations
54. FIG. 3H has an inner edge 50 and an outer edge 52 with
corrugations 54 that are present at the outer edge 52 but not at
the inner edge 50. In an alternate embodiment, the corrugations
could be formed at the inner edge 50, but not at the outer edge
52.
[0040] FIG. 3J is a perspective view of a buttress 12 showing an
embodiment wherein the adaptive opening results from corrugations
54. FIG. 3J has a central non-corrugated or planar region 56 with a
corrugated area from the outer perimeter of the corrugated or
planar region 58 to the outer edge of the buttress 52.
[0041] FIG. 3K is a perspective view of a buttress 12 showing an
embodiment wherein the adaptive opening results from corrugations
54 of the inner region of the buttress. FIG. 3K has an outer
non-corrugated or planar region 78 that surrounds the central
region having corrugations 54.
[0042] In each of the buttresses depicted in FIGS. 3G, 3H, 3J, and
3K, the adaptive opening resulting from corrugations 54 are sized
and placed so that some part of the adaptive opening remains on the
portion of the buttress 12 that remains in the patient after the
cutting action of the blade of a circular stapler.
[0043] It is anticipated that designs other than those depicted in
FIGS. 3A-3H, 3J and 3K may be used for the relief features on the
buttresses 12. These various relief features allow for the anvil
head 16 of a circular stapler 10 to pass through a buttress 12
without tearing or substantially altering the buttress 12, even
though the anvil head 16 compression surface 18 has an outer
diameter larger than the inner diameter of the hole formed in the
buttress 12 when a generally circular, concentric cutting blade of
the circular stapler 10 has been used to cut the hole in the
buttress 12.
[0044] Self alignment of the buttress 12 onto a circular surgical
stapler is another important aspect of this invention. Self
alignment insures that the buttress is generally aligned to
coincide with and cover the pattern of staples ejected from the
stapler. The buttress 12 may be self-aligned using an opening in
its central region sized to closely fit the central shaft of a
circular stapler with which it is used. Alternatively, the buttress
12 may be self-aligned using the outer diameter of the stapler
anvil compression surface 18 and the outer diameter of the stapler
body compression surface 20. FIGS. 3A-3H, 3J, 3K, 6A and 6B show
buttresses 12 adapted to self align using openings in their central
regions. FIG. 6A shows a perspective view of a buttress 12 which
has an opening feature 61 in its central region. FIG. 6B shows a
cross section of the buttress shown in FIG. 6A. Surface 60 in FIG.
6B contacts the outer diameter of the central shaft 14 (FIG. 1B) of
a circular stapler 10. FIG. 6C shows a perspective view of a
buttress 12 which is adapted to self align onto the outer diameter
of the stapler anvil compression surface 18 (FIG. 1B) or outer
diameter of the stapler body compression surface 20 (FIG. 1B). FIG.
6D shows a cross section of the buttress shown in FIG. 6C. Surface
62 in FIG. 6D contacts the outer diameter of the stapler anvil
compression surface 18 (FIG. 1B) or outer diameter of the stapler
body compression surface 20 (FIG. 1B) to insure self alignment.
[0045] The buttress 12 can be made of a constant thickness or can
be made of varying thickness, densities or materials of
construction through their cross sections. Varying thicknesses,
densities or materials of construction can be of advantage in some
embodiments. For example, greater thickness or use of a denser
material in the central region of the buttress would add rigidity,
potentially aiding in self-aligning of the buttress 12 on the
circular stapler 10. Thickness, density or material variations may
also help to prevent deformation of the buttress 12 as the circular
stapler is used in the process of pulling the stapler anvil 16
toward the stapler body 22 (as depicted in FIGS. 2B and 2C). This
thicker or higher density material could be limited to the central
region of the buttress so that the generally circular concentric
cutting blade of the stapler 10 would cut through or around this
thicker material and remove it while the stapler was being
withdrawn. In another embodiment, thinner or less dense material
could be made to generally coincide with the cutting diameter of
the generally circular concentric cutting blade of the selected
circular stapler to facilitate the cutting process. Alternatively,
thicker, more dense or stronger material could be constructed into
the buttress 12 so as to coincide with the areas where the staples
are placed with thinner, less dense or weaker material used in
other areas.
[0046] Three embodiments of buttresses 12 of varying cross sections
are shown in FIGS. 4A-4C. FIG. 4A shows the side view of a buttress
12 that has a silicone disk 36 attached to it. The silicone disk 36
may be approximately 0.5 mm thick, made, for example, with Nusil
MED 4080 (NuSil Technology, Carpinteria, Calif.) and can be
provided with center hole sized to form a slight interference fit
with the central shaft 14 of a circular stapler 10. The
interference fit between the central shaft 14 of the stapler and
the center hole in the silicone disk 36 provides for a means to
securely fasten the buttress 12 to the circular stapler without an
adhesive. The outer diameter of this silicone disk 36 is sized to
correspond with the central region of the buttress 12, fitting
within the diameter of the generally circular concentric cutting
blade of a circular stapler 10.
[0047] One side of the silicone disc 36 is adhered to one side of
the buttress 12 by covering one side of the disc 36 with a thin
coating of a pressure sensitive adhesive formulation of silicone
(e.g., NuSil MED 1356, NuSil Technology, Carpinteria, Calif.).
After a 30 minute drying period, disc 36 may be placed onto one
surface of buttress 12 with the adhesive coated surface of the
silicone disk 36 facing towards the surface of the buttress 12 as
illustrated in FIG. 4A. Compressive force is then applied to the
silicone disk 36 to assure adequate bonding between of the silicone
disk 36 to the buttress 12.
[0048] Other means of making the central section of the buttress 12
thicker may be used, such as using materials other than silicone or
building up more self-cohering non-woven web thickness.
[0049] FIG. 4B shows the side view of a buttress 12 where the
central region 37 is thicker due to the process of adding more
material to the central region in comparison to the thickness
adjacent the perimeter. FIG. 4C shows the top view of a buttress 12
where the central section 42 is made with thicker or higher density
material. Spokes 44 emanating from the central section 42 are also
made with thicker or higher density material. A perimeter area 46
of the buttress 12 as depicted can also be made with a thicker or
higher density material to increase the strength of the material
for staple reinforcement. The buttresses 12 depicted in FIGS. 3A-3E
and 4A-4C and other designs that can be contemplated may also be
constructed in a modular fashion such that individual materials can
be combined to form the final device.
[0050] Additionally, buttresses 12 of various designs including
those depicted in FIGS. 3A-3H, 3J, 3K, and 4A-4C can be used with a
circular stapler that has a round or non-round central shaft.
Circular staplers with non-round shafts with buttresses 12 having
central openings corresponding to the shape of the shaft could
facilitate indexing of the buttresses 12 to locations relative to
the stapler anvil and body compression surfaces 18 and 20.
[0051] A buttress 12 can be constructed to exhibit either
essentially elastic or essentially inelastic behavior. Essentially
elastic behavior occurs when a buttress 12 is adequately deformable
so as to allow an anvil head 16 of larger outer diameter to pass
through the smaller diameter opening formed in the buttress 12 by
the circular stapler cutting blade without causing permanent
alteration or damage to the cut edge of the opening formed by the
cutting action of the circular stapler blade. Permanent alteration
of the cut edge results from tears, rips, or other permanent
deformation. Essentially inelastic behavior occurs when an anvil
head 16 of larger outer diameter than the smaller diameter opening
formed in a buttress 12 by the circular stapler cutting blade
causes permanent alteration or damage to the cut edge of the
opening formed by the circular stapler cutting blade. The
essentially inelastic buttress 12 by definition would rip, tear, or
otherwise retain permanent alteration to the cut edge of the
opening formed by the circular stapler cutting blade after passing
the larger diameter anvil head 16 through the smaller opening
formed by the circular stapler cutting blade. A buttress may be
made from either relatively elastic (e.g., silicone) or relatively
inelastic materials (e.g., PGA:TMC). If made from relatively
inelastic materials, the buttress may be fabricated in such a way
as to now possess essentially elastic behavior. For example,
inelastic materials may be fabricated into a material possessing a
degree of porosity, such as a weave or a web, wherein the porosity
provides for adequate flexibility thereby allowing the resulting
buttress to demonstrate essentially elastic behavior.
[0052] The relief features shown in FIGS. 3A-3H, 3J and 3K as well
as others can be used with either essentially elastic or
essentially inelastic buttresses 12. These relief features will be
required, however, for buttresses 12 that without such relief
features would exhibit essentially inelastic behavior.
[0053] FIG. 5A shows the top view of a buttress 12 which has a
central opening 30 sized to closely fit the outside diameter of a
central tubular shaft 14 of a circular stapler 10. FIG. 5B shows
the top view of a buttress 12 after a hole with a cut edge 38 has
been cut through it by the action of a generally circular
concentric cutting blade of a circular stapler 10. FIG. 5C shows
the top view of a buttress 12 constructed to be elastic after a
circular stapler anvil head 16 with a compression surface 18 that
has an outer diameter larger than the diameter of the cut edge 38
of the opening formed by the action of a generally circular
concentric cutting blade has been passed through it. No substantial
permanent alteration or damage is made to the cut edge 38 of the
opening formed by the generally circular concentric cutting blade
of the circular stapler.
[0054] FIGS. 5D, 5E and 5G show the top and side views of
buttresses 12 that are inelastic and without relief features such
as shown in FIGS. 3A-3H, 3J and 3K, after pulling through a
circular stapler anvil head 16 with a compression surface 18 that
has an outer diameter larger than the diameter of the cut edge 38
of an opening formed by the action of a generally circular
concentric cutting blade. These buttresses 12 show substantial
permanent alteration or damage to the cut edge 38 area of the
opening formed by the action of a generally circular concentric
cutting blade of a circular stapler 10. FIG. 5D of an inelastic
buttress 12 shows tears 48 around the cut edge 38 of the opening
caused by pulling through a circular stapler anvil head 16 with a
compression surface 18 that has a larger diameter than that of the
opening. FIGS. 5E and 5G of an inelastic buttress 12 show
deformation 49 around the cut edge 38 of the opening caused by
pulling through a circular stapler anvil head 16 with a compression
surface 18 that has a larger diameter than that of the opening.
Other modes of substantial permanent alteration or damage of the
cut edge 38 can be contemplated.
[0055] In order to evaluate the compatibility of buttresses of the
present invention with circular staplers, two buttresses of 67%
PGA:33% TMC (w/w) having a web density of about 0.5 g/cc. These
buttresses were made to have a circular shape with an outside
diameter of approximately 30 mm, for use with a circular stapler
(ILS 29 mm, Ethicon Endosurgery, Somerville N.J.). The buttresses
were of uniform thickness of about 0.25 mm, and were provided with
a center hole of about 6.3 mm diameter. The central region of each
buttress was also provided with a circular silicone stiffener
having a diameter of about 19.1 mm and a thickness of about 0.5 mm.
Each of these stiffeners was provided with a 6.3 mm diameter hole
at its center. One stiffener was adhered to one side of each
buttress with the center holes through each component aligned,
using MED-1356 silicone adhesive, Nusil technologies, Carpenteria
Calif.
[0056] A 30 cm section of porcine colon was obtained and cut in
half; purse string sutures were made on adjacent ends of the large
bowel sections. The anvil, with first buttress in place with the
stiffener facing the stapler body, was fed through one section so
that the anvil post protruded through the hole in the
purse-stringed end. The stapler body, with the shaft extended and
with the second buttress in place with the stiffener facing the
anvil, was advanced through the adjacent colon tissue until the
post protruded through the purse-stringed hole. The anvil post was
mated to the body shaft and closed via the actuator knob on the
proximal end of the device according to the manufacturer's
instructions for use. After firing the stapler and rotating the
actuator knob two full turns, the stapler was rotated 90 degrees
relative to the anastomosis in both directions and then removed
from the colon tissue, pulling the anvil through the anastomosis.
Both sides of the anastomosis were observed visually for integrity
of the buttresses after removing the anvil (of 28.6 mm outside
diameter) through the cut hole (of 20.8 mm diameter). All staples
on both sides of the anastomosis were captured and no signs of
tearing or disfigurement were observed.
[0057] An additional pair of buttresses was fabricated and tested
in the same manner. Each buttress of this additional pair was
provided with four slits through the thickness of the material,
spaced 90 degrees apart and extending radially outward from a point
1.9 mm from the edge of the center hole for a length of 7.6 mm.
During testing, this pair was determined to be equally effective as
the first pair.
[0058] While the principles of the invention have been made clear
in the illustrative embodiments set forth herein, it will be
obvious to those skilled in the art to make various modifications
to the structure, arrangement, proportion, elements, materials and
components used in the practice of the invention. To the extent
that these various modifications do not depart from the spirit and
scope of the appended claims, they are intended to be encompassed
therein.
* * * * *