Note: Descriptions are shown in the official language in which they were submitted.
CA 02530141 1995-04-25
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CIRCULAR ANASTOMOSIS DEVICE
This application is a division of copending
Canadian Application Serial NO. 2,147,800, filed April 25,
1995.
BACKGROUND
1. Field of the Invention
This invention relates to a surgical fastener
applying instrument. More particularly, this invention
relates to an arrangement for a circular anastomosis
surgical stapling instrument.
2. Description of the Related Art
Various types of surgical fastener applying
instruments have been known for the application of surgical
fasteners to tissue. For example, it has been known to use
various types of surgical staplers in gastric and esophageal
surgery in both classic or modified gastric reconstructions
performed end-to-end, end-to-side or side-to-side. In many
cases, instruments, such as described in U.S. Patent No.
4,603,693, have been used where an anvil assembly mounted on
the end of a center rod can be manipulated relative to a
staple assembly on the end of a tubular housing of the
instrument. In instruments of this nature, the center rod
is connected with a mechanism, for example, which employs a
wing nut at the proximal end of the instrument, so that the
rod can be moved back and forth independently of the staple
assembly so as to adjust the anvil assembly relative to the
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staple assembly. Likewise, a pusher tube is mounted within
the instrument for movement via a handle mechanism so as to
cause a firing of the staples from the staple assembly
towards the anvil assembly.
In some instruments, such as described in U.S.
Patent No. 4,351,466, these stapling instruments have been
provided with a pair of handles in order to actuate the
pusher tube to cause a firing of the staples. In such
cases, each handle has been pivotally mounted so as to be
moved toward the other handle during manual squeezing by a
surgeon. Each handle also includes a lever arm within the
instrument which engages against the pusher tube so as to
move the tube in a proximal direction. In most surgical
stapling applications, proper staple formation is very
important to achieve the desired anastomosis. As such,
proper alignment of parts during manufacture and precise
mechanisms to control staple formation during use are
advantageous.
Circular stapling instruments have also been
provided with safety locks in order to prevent the squeezing
together of the handles prematurely. That is, the safety
locks have been provided in order to prevent the handles
from moving towards each other before a surgeon has
manipulated the anvil assembly into position for the firing
of the staples. While these instruments have been used
safely and effectively for years, it would be advantageous
to provide the feature of preventing the anvil member from
being able to be moved once a fastener firing safety lock
has been released. Also a continuing need exists to develop
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these types of surgical stapling instruments which require fewer parts and
materials to manufacture, thereby reducing costs of production and requiring
less
labor to assemble the parts. Additionally, if the instruments are disposable,
i.e.
single use only, use of less materials is desirable to decrease the amount of
medical waste generated during a surgical procedure.
In some applications of circular anastomosis devices, tissue must be
pierced in order to connect the stapling mechanism and anvil member. U.S.
Patent No. 5,119,983 discloses a removable tip portion to facilitate this
procedure.
After piercing tissue, the tip portion is removed and the anvil is joined to
the
stapler. U.S. Patent No. 5,104,025 discloses a tip portion for piercing tissue
and a
rigid sleeve for protecting the tip portion. The entire rigid sleeve
reciprocates
relative to the tip portion by means of a spring to expose the tip portion.
The
spring also serves to secure the sleeve to the stapling head portion of the
instrument. While the removable tip embodiment of U.S. Patent No. 5,119,983
has been used successfully for years, there is always a need for more cost
efficient
devices.
SUMMARY
In accordance with an embodiment of the present invention there is
provided a surgical instrument for applying at least one circular array of
fasteners,
comprising: a housing having proximal and distal end portions; an elongated
shaft extending f'rom the housing distal end portion, the shaft having
proximal and
distal end portions; a fastener head portion assembly positioned at the shaft
distal
end portion, the fastener head portion assembly including an assembly housing,
a
plurality of surgical fasteners disposed within the housing, a pusher member
including a plurality of pusher fingers operatively associated with the
surgical
fasteners, a knife member disposed within the housing and a fastener crimping
limit member disposed within the housing; an anvil operatively disposed
adjacent
the fastener head portion assembly, and wherein the fastener crimping limit
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member is positioned to engage the anvil to limit movement of the pusher
fingers
to limit the degree to which the surgical fasteners are crimped.
Preferably, the fastener crimping limit member includes a base having a
longitudinal portion extending therefrom which is operatively associated with
the
anvil member to limit the crimping of the surgical fasteners upon firing of
the
instrument.
In another preferred embodiment, the fastener crimping limit member
includes a base having a plurality of longitudinally extending finger portions
projecting therefrom which are operatively associated with the anvil member to
limit the crimping of the surgical fasteners upon firing of the instrument.
In a further preferred embodiment, there is provided an adjusting member
operatively associated with the fastener carrying cartridge to adjust the
longitudinal positioning of the fastener carrying cartridge relative to the
distal end
of the shaft.
Preferably, an elongated anvil carrying member is provided which is
reciprocatingly movable within the fastener containing cartridge, defining a
hollow distal portion forming a sharp tip at a distal end thereof.
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BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are
described hereinbelow with reference to the drawings
wherein:
Fig. 1 is a perspective view of an instrument for
applying surgical fasteners to tissue;
Fig. 2 is an exploded perspective view of an
instrument;
Fig. 3 is a top plan view of the fastener firing
member;
Fig. 4 is a side plan view of the fastener firing
member;
Fig. 5 is an end view of the fastener firing
member;
Fig. 6 is a top plan view of the elongated member
for moving the anvil relative to the stapling cartridge;
Fig. 7 is a side plan view of the elongated member
of Fig. 6;
Fig. 8 is a cross-sectional view taken along
section line 8-8 of Fig. 6;
Fig. 9 is a cross-sectional view taken along
section line 9-9 of Fig. 7;
Fig. 10 is a plan view of the instrument showing
the lever members in the unfired position;
Fig. 11 is a cross-sectional view taken along
section line 11-11 of Fig. 10;
Fig. 11A is an enlarged view of the area indicated
in Fig. 11;
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Fig. 12 is a plan view of the instrument showing
the lever members in the fired position;
Fig. 13 is a cross-sectional view taken along
section line 13-13 of Fig. 12;
Fig. 13A is an enlarged view of the area indicated
on Fig. 13;
Fig. 14 is a perspective view of another
embodiment of the instrument for applying surgical fasteners
to tissue;
Fig. 15 is an exploded perspective view of the
instrument of Fig. 14;
Fig. 16 is an enlarged, partially cut away cross-
section view of the insert guide of the instrument of Fig.
14;
Fig. 17 is an enlarged exploded view of the distal
of the instrument of Fig. 14; and
Fig. 18 is an enlarged view of the distal end of
the elongate member and sharp tip of the instrument of Fig.
14.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in specific detail to the drawings,
in which like reference numerals identify similar or
identical elements throughout the several views, and
initially to Fig. 1, which shows one embodiment of the
surgical instrument for applying a circular array of
fasteners illustrated in perspective view as instrument 10.
Instrument 10 includes elongate body portion 12 and handle
section 14. Handle section 14 includes anvil adjustment
member 16, lever lockout or safety member 18 and fastener
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firing levers 20. Fastener head portion 22 and anvil member
24 are disposed at the distal end of body portion 12.
Except where noted otherwise, the materials utilized in the
components of the surgical instrument generally include such
material as polycarbonate for housing sections and related
components, and stainless steel for such components which
transmit forces. One preferred polycarbonate material is
LEXAN brand polycarbonate available from General Electric
Company. However,
30
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equivalent alternative materials will readily come to the
mind of those skilled in the art.
Referring now to Fig. 2, the various components of
instrument 10 are shown in exploded view. Instrument 10
includes body or housing half sections 12a and 12b which are
preferably molded and joined together by suitable fastening
means such as rivets 28, or the like. To control axial
movement of anvil member 24, elongated member 30 is slidably
mounted within body portion 12, preferably by being securely
mounted to helical cam member 32 by any suitable means such
as, for example, welding or the like. Helical cam member 32
is slidably mounted within anvil adjustment member 16 by way
of bushing 34 which is securely mounted in open end 36 of
anvil adjustment member 16. Friction member 93 is disposed
adjacent anvil adjustment member 16 to prevent relatively
free rotation of the anvil adjustment member. In a
preferred embodiment, both the mounting of bushing 34 and
the camming of helical cam 32 is accomplished by compound
pin 38 which has central portion 38a and extending portions
38b and 38c which are of reduced diameter. Portions 38a and
38b are press fitted into bores 40 and 42, respectively,
located on bushing 34 and anvil adjustment member 16,
respectively. Lower extending portion 38c serves as a
camming pin and fits within the helical groove formed on the
surface of helical cam 32. Anvil approximation indicator
member 46 has extended portion 48 and is press fitted into
proximal portion 50 of helical cam 32. Cap 51 is attached
to proximal end 52 of anvil approximation indicator member
46. Cap 51 is preferably a colored piece which is easily
visible through opening 54 formed near the proximal end of
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anvil adjustment member 16 to provide indication to the user
when the anvil member is in the proper position for firing
of the instrument. The distal end of elongated member 30 is
provided with means to retain anvil member 24, which will be
described in more detail below.
The fastener firing mechanism of instrument 10
includes fastener firing member 56 which is slidably mounted
within body portion 12 preferably such that fastener firing
member 56 is disposed around elongated member 30. Fastener
firing member 56 is preferably biased in a proximal
direction by suitable biasing means such as spring 58.
Fastener firing levers 20 are pivotably mounted to body
portion 12 and have extended portions 60 which cross over
each other in scissor-like fashion. Bearing block 62 is
mounted on fastener firing member 56, for example, being
held between flexible finger portions 64 and raised portions
66 which are formed in the side walls of fastener firing
member 56, as best illustrated in Figs. 3 and 4. Fastener
firing member 56 has bearing surfaces such as tabs 68 formed
at the distal portion which serve to urge a pusher member
within fastener head portion 22 in a distal direction in
order to eject surgical fasteners 69, such as stainless
steel or titanium staples, from fastener head portion 22.
Also disposed on instrument 10 are lever lockout
member 18 and elongate member lockout member 70. Lever
lockout member 18 is preferably spring biased to the locked
out position by spring 67 in slot 91. Each of these lockout
members are preferably mounted on instrument 10 in such a
manner that they are fixed relative to each other and upon
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pivoting of lever lockout member 18, elongate member lockout
member 70 also pivots. With reference to Figs. 11A and 13A,
elongate member lockout member 70 has shoulder portions 73
and 75 formed therein as well as inwardly extending tab 79.
5 The function of each of these portions of elongate member
lockout member 70 will be described in further detail later
herein.
Referring now to Figs. 3-9, the structural and
10 functional details of fastener firing member 56 and
elongated member 30 will now be described in detail. In
Figs. 3-5, fastener firing member 56 is shown as preferably
being a generally U-shaped member formed from material which
can transmit forces effectively and reliably such as
stainless steel. Fastener firing member 56 has side walls
72 and 74 which are connected by web 76. To fit fastener
firing member 56 within the curved section of body portion
12, fastener firing member 56 has extended portions or
flexible bands 72a and 74a which are preferably formed
integrally with walls 72 and 74, respectively. Band 72a is
shorter than band 74a. The difference in the length of the
two bands corresponds to the amount of curvature of body
portion 12 so that when fastener firing member 56 is mounted
in body portion 12, the surfaces of tabs 68 form a plane
parallel with the surface of the fastener pusher member (not
shown).
Referring to Figs. 6-9, elongated member 30 is shown
as a U-shaped member, similar to fastener firing member 56.
Elongated member 30 has side walls 78 and 80 which are joined
by web 82. However, the cross-section dimensions of elongated
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member 30 are preferably such that elongated member 30 readily
fits within fastener firing member 56. This arrangement is
desirable so that elongated member 30 and fastener firing
member 56 can slide independent of each other. As with
fastener firing member 56, elongated member 30 must also be
formed to fit within the curved contour of body portion 12. To
accomplish this curvature, elongated member 30 has extended
portions or flexible bands 78a and 80a which are preferably
formed integrally with walls 78 and 80, respectively. Similar
to the construction of fastener firing member 56, bands 78a
and 80a of elongated member 30 are of different length.
Elongated member 30 terminates at a distal end in a pair of
opposed anvil retaining portions 84 and 86. Preferably,
structure can be provided within body portion 12 (see 320 in
Fig. 15) that serves to retain the side walls and bands of
both elongated member 30 and fastener firing member 56. Such
structure can be of unitary construction and have grooves to
direct longitudinal movement of the channels and bands.
Additionally, one or more seals (see 326a and 326b in Fig. 15)
can be disposed within body portion 12 to prevent the flow of
gases therethrough.
To facilitate retaining anvil member 24, and in
particular, the anvil shaft therein, anvil retaining
portions 84 and 86 are preferably semi-circular in shape as
best illustrated in the cross-section view of Fig. 8. To
assist in retention of anvil 24, anvil retaining portions 84
and 86 are provided with flexible finger portions 88 and 90,
respectively, each of which have a raised portion formed
thereon, such as camming and retaining portions 92 and 94,
respectively. Camming surfaces 96 and 98 formed by camming
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and retaining portions 92 and 94, respectively serve to cam
flexible finger portions 88 and 90 radially outward upon
insertion of the anvil into the distal end of instrument 10.
Referring temporarily back to Fig. 2, once annular groove
portion 100 of anvil shaft 102 passes between retaining
portions 84 and 86, flexible finger portions 88 and 90
return toward their initial or at rest state so that
retaining portions 92 and 94 seat in annular groove 100.
In a preferred embodiment, extended portions 78a
and 80a of elongated member 30 are preferably bent until the
ends of anvil retaining portions 84 and 86 are aligned and
are then.permanently joined together (as shown in Fig. 2),
by suitable bonding techniques, such as, by welding.
At the proximal end of elongated member 30, cut
out portion 83 is formed to receive elongate member lockout
member 70 when elongated member is properly positioned for
firing the staples of instrument 10. As best illustrated in
Figs. 6 and 7, cutout portion 83 is preferably formed
through most of web 82 and continues partially up side wall
80.
The basic steps of operation are set forth in
several patents, such as U.S. Patents 4,576,167 issued to
Noiles, 5,005,749 issued to Aranyi, and 5,119,983 to Green
et al.
With reference to the instrument of the present
invention, the user positions the tissue to be joined
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between anvil 24 and fastener head portion 22. Anvil
adjustment member 16 is rotated to move elongated member 30
and anvil 24 proximally until the user sees approximation
indicator 46 appear in opening 54 of anvil adjustment"member
16. During this step, elongate member 30 acts as a tension
member as it pulls anvil 24 into position adjacent fastener
head portion 22. Prior to alignment of cut out 83 in
elongate member 30 and extended portion 79 of elongate
member lockout 70, lockout 70 is prevented from pivoting by
contact between extended portion 79 and elongate member 30.
When cut out 83 is positioned adjacent extended portion 79
of elongate member lockout 70, as further described below,
lever lockout member 18 and elongate member lockout 70 are
able to be pivoted by depressing, usually with the thumb, on
lever lockout member 18. Members 18 and 70 can be
interconnected by any suitable means, i.e., protrusion from
one member entering a recess in the other. Once lever
lockout member 18 is pivoted by the user, fastener firing
levers 20 are depressed to urge fastener firing member 56 in
a distal direction. This motion is accomplished by the
camming effect of extended portions 60 of fastener firing
levers 20 on bearing block 62 the distal movement of
fastener firing member 56 urges fastener pusher members to
eject fasteners 69 from fastener head portion 22. During
this step, fastener firing member 56 acts as a compression
member as it ejects fasteners 69.
With the above operational description of instrument
10 as a general base of the overall operation, the operation
of elongate member lockout 70 will now be described in detail
with reference to Figs. 10-13. Once the user has instrument
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inserted and the tissue to be joined is properly situated
about the distal end of the instrument, anvil 24 is
approximated to its proper position by rotation of anvil
adjustment member 16, instrument 10 is positioned for firing,
5 as shown in Fig. 10. In that position, however, fastener
firing member 56 is still blocked from movement due to lever
lockout member 18 still being oriented in the "safety on"
position, i.e., lever locking extended portions 104 and 106
(Fig. 2) are aligned with the structure of levers 20 so that
10 they cannot be depressed. Pivoting of lever lockout member 18
is prevented when elongated member 30 is out of the desired
approximation range for firing the staples.
With reference to Figs. 2-7, 11 and 13, prevention
of the ability to pivot lever lockout member 18 is
accomplished by the relative position of elongated member 30
and thus the approximation of anvil 24. When anvil 24 is not
properly approximated, side wall 80 and web 82 of elongated
member 30 prevent extended portion 79 of elongate member
lockout 70 from moving further inward (Fig. 11). However,
once elongated member 30 is properly positioned, i.e., cut out
83 is aligned with extended portion 79 of elongate member
lockout 70, then lever lockout member 18 which is fixedly
secured to elongate member lockout member 70, can be pivoted,
as shown in Fig. 13. When lockout 70 is pivoted, shoulder
portions 73 and 75 of lockout 70 are moved out of notches 77
of fastener firing member 56 (Figs. 3 and 4). This enables
fastener firing levers 20 to be pivoted toward each other as
shown in Fig. 12, thereby moving fastener firing member 56
distally and ejecting fasteners 69 from fastener head portion
22. As can be seen in Figs. 13 and 13A once lever lockout 18,
CA 02530141 1995-04-25
and elongate member lockout 70 are pivoted by the user,
inwardly extending portion 79 of lockout 70 enters into cut
out 83 (Figs. 6 and 7) and blocks elongated member 30 from
movement in either a proximal or distal direction.
5
Referring now to Figs. 14-18, another embodiment of
the present invention shown as instrument 210 will now be
described. For purposes of clarity, components of the
instrument of Figs. 14-18 which are similar or identical to
10 those of the embodiment for Figs. 1-13 have been labeled by
adding 200 to the reference numerals of the earlier
embodiment. For example, anvil shaft 102 of Fig. 2
corresponds to anvil shaft 302 of Fig. 15.
15 Referring now to Fig. 14 in conjunction with Fig.
15, instrument 210 includes insert guide 320 which is
preferably molded of a polycarbonate material such as LEXAN
available from the General Electric Company. Insert guide 320
is preferably molded to conform to the curvature of housing
half sections 212a and 212b so as to provide structural
support for elongate member 230 and fastener firing member
256. Referring temporarily to Fig. 16, insert guide 320 is
illustrated in a partially cut away section to show the guide
tracks which receive elongate member 230 and fastener firing
member 256 therein. Specifically, outer guide tracks 322 are
molded to receive sidewalls 272 and 274 therein and inner
guide tracks 324 are formed to receive side walls 78 and 80 of
elongate member 30 therein. Insert guide 320 thereby provides
structural support upon longitudinal motion of either elongate
member 230 or fastener firing member 256, particularly at the
point of curvature thereof. Insert guide 320 effectively
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reduces possible force transmission losses upon operation of
instrument 210.
In order to provide an internal seal in body portion
212, seal half sections 326a and 326b are formed to fit around
notches formed on insert guide 320. Seal half sections 326a
and 326b are preferably molded of a hard rubber material which
is molded to conform with the inner dimensions of housing half
sections 212a and 212b. Additionally, seal half sections 326a
and 326b are molded to fit over elongate member 230 and
fastener firing member 256 so as to form a seal between the
internal section of the instrument 210 which is distal of the
seal half sections 326a and 326b and the internal portions of
instrument 210 which are proximal of seal half sections 326a
and 326b so as to inhibit the passage of gases thereby.
Referring now to figure 15 in conjunction with Fig.
17, additional features of the present invention are
illustrated therein which will now be described. An adjusting
member such as collar 328 is mounted between the distal end of
housing 212 and the=proximal end of fastener head portion
assembly 222. Collar 328 has ratchet teeth 330 formed on an
inner surface thereof at the proximal end. Ratchet teeth 330
cooperate with ratchet teeth 332 formed on the distal end of
housing half sections 212a and 212b. Ratchet teeth 330 and
332 interact to provide for rotational advancement of collar
328 in a single direction. Also formed on collar 328 are
camming surfaces 334 and 336 which interact with camming
surfaces 338 and 340 formed at the proximal end of fastener
head portion 222. A purpose of collar 328 is to provide for
post instrument assembly adjustment of the relative
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longitudinal positioning of fastener head portion assembly 222
with respect to the distal end of body portion 212. This
adjustment capability is important so that instrument 210 may
be calibrated to insure the proper positioning of anvil member
224 when cap 251 of anvil approximation indicator member 246
is positioned within opening 254 so as to indicate that
instrument 210 is ready for firing of surgical staples 269.
Once instrument 210 is properly calibrated, collar member 328
may be fixedly secured to the distal end of body portion 212
so that collar 328 is not permitted to rotate with respect
thereto. This attachment may be accomplished by known
suitable means such as, for example, bonding and/or by the use
of a fastener such as a screw or a pin.
Another important feature illustrated in Fig. 17
provides protection against over crimping of surgical staples
269 upon firing of instrument 210. Pusher back 342 is
provided with longitudinally extending portions 344 which are
configured to fit inside of knife ring 346 and are preferably
sized to abut against a surface portion, such as cut ring 345,
of anvil 224 upon firing of instrument 210. When portions 344
of pusher back 342 contact a portion of anvil 224, pusher
fingers 252 are prevented from traveling further, thereby
limiting the degree to which surgical staples 269 may be
crimped against anvil 224.
In another feature of the present invention,
referring now Fig. 15 in conjunction with Fig. 18, elongate
member 230 has tip 354 formed at the distal end to facilitate
puncturing of tissue as desired by the user of instrument 210.
Tip 354 is preferably sharp and formed by known methods such
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as, for example, grinding with suitable abrasives. Tip 354 is
formed such that a hollow passageway or opening 356 is formed
which passes longitudinally through the distal end portion of
elongate member 230. Opening 356 on elongate member 230 is
preferably sized so that it can receive shaft 302 of anvil 224
so that anvil 224 may be reta~ned by the distal end portion of
elongate member 230 in a similar manner as set forth above for
elongate member 30 and anvil 24 for the embodiment of Figs. 1-
13. To avoid inadvertent lateral contact with tip 354 a
protective cover is provided, such as cover 358 which is
preferably formed of a deformable elastomeric material. Cover
358 is provided with raised portions 360 which correspond to
bores 362 formed on elongate member 230 proximal of tip 354.
In use, when elongate member 230 is extended past head portion
assembly 222, cover 358 deflects upon contact with tissue to
expose tip 354. After tip 354 and cover 358 pass through the
tissue, cover 358 returns to a position which protects tip
354, thereby providing means for preventing inadvertent trauma
by tip 354 to surrounding tissue.
The operation of instrument 210 is similar to that
of instrument 10 except as noted hereinabove. Accordingly, no
separate description of the operation of instrument 210 will
be provided at this point.
While the invention has been particularly shown, and
described with reference to the preferred embodiments, it will
be understood by those skilled in the art that various
modifications and changes in form and detail may be made
therein without departing from the scope and spirit of the
invention. Accordingly, modifications such as those suggested
CA 02530141 1995-04-25
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above, but not limited thereto, are to be considered within
the scope of the invention.
