U.S. patent application number 11/130859 was filed with the patent office on 2006-01-05 for surgical stapling system.
This patent application is currently assigned to Datascope Investment Corp.. Invention is credited to Diego Y. Fontayne.
Application Number | 20060000869 11/130859 |
Document ID | / |
Family ID | 35451360 |
Filed Date | 2006-01-05 |
United States Patent
Application |
20060000869 |
Kind Code |
A1 |
Fontayne; Diego Y. |
January 5, 2006 |
Surgical stapling system
Abstract
A system is provided for joining two tubular structures by a
surgical stapling procedure. The system includes a series of
sizers, a specifically designed graft, a loading unit, a wand, a
surgical loop and a stapling instrument. The sizers are for
determining the diameter of a target aorta and the availability of
a sufficient transected aortic length to perform a stapling
procedure. The loading unit holds the graft in position in the body
and deploys a circumferential line of staples through the graft and
an overlapping end of the aorta. The graft may include a side port
by which the loading unit holds the graft during the stapling
procedure, and which may be closed once the stapling procedure has
been completed. The wand may be used to introduce the loading unit
and graft into the body, to position them within the transected
aorta, and to hold them in place during the application of the
surgical loop. The surgical loop may include a band formed from a
flexible material and having a width greater than its thickness so
as to facilitate the formation of an annular loop. With the
surgical loop holding the aorta and graft in relative overlapping
positions, the wand may be removed from the loading unit and the
stapling instrument may be assembled thereto. The stapling
instrument includes a plurality of anvils which may be closed to
form a circle overlying the aorta, and a trigger mechanism for
firing the staples. When fired, the staples are deployed radially
outward through the graft and aorta, whereupon their free ends are
bent inwardly by staple returns on the anvils. As a result, a
plurality of staples may be simultaneously deployed quickly and
accurately in a circumferential pattern so as to join together two
tubular structures. The system may be used in either an open
surgical procedure or laparascopically.
Inventors: |
Fontayne; Diego Y.;
(Montebello, NY) |
Correspondence
Address: |
LERNER, DAVID, LITTENBERG,;KRUMHOLZ & MENTLIK
600 SOUTH AVENUE WEST
WESTFIELD
NJ
07090
US
|
Assignee: |
Datascope Investment Corp.
Montvale
NJ
|
Family ID: |
35451360 |
Appl. No.: |
11/130859 |
Filed: |
May 17, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60571738 |
May 17, 2004 |
|
|
|
Current U.S.
Class: |
227/175.1 |
Current CPC
Class: |
A61B 2017/1107 20130101;
A61F 2/06 20130101; A61B 17/115 20130101; A61B 17/12013 20130101;
A61F 2002/061 20130101; A61B 17/072 20130101; A61B 17/1155
20130101; A61F 2/9517 20200501; A61F 2002/065 20130101; A61B
2017/1157 20130101 |
Class at
Publication: |
227/175.1 |
International
Class: |
A61B 17/04 20060101
A61B017/04 |
Claims
1. A surgical stapler for joining a tubular prosthetic graft to a
body lumen, the surgical stapler comprising: a handle having a
proximal end and a distal end; a loading unit removably connected
to the distal end of the handle, the loading unit including a body
adapted for insertion into the prosthetic graft; an anvil assembly
having an open position and a closed position, the anvil assembly
in the closed position being spaced around and relatively close to
the body of the loading unit, and the anvil assembly in the open
position being spaced relatively distant from the body of the
loading unit; a plurality of staples arranged in the body of the
loading unit for deployment along paths extending radially outward
from the loading unit; a deployment mechanism operable to urge the
plurality of staples outward from the loading unit along the radial
paths; and an actuating mechanism at the proximal end of the handle
and operable to actuate the deployment mechanism, whereupon the
plurality of staples are simultaneously urged radially outward from
the loading unit along the radial paths.
2. The surgical stapler as claimed in claim 1, wherein the loading
unit includes a plurality of prongs arranged radially in the body,
the prongs having a recessed position within the body for inserting
the body into the prosthetic graft, and an extended position
projecting radially outward from the body for holding the
prosthetic graft in an assembled position on the loading unit.
3. The surgical stapler as claimed in claim 2, wherein the
plurality of prongs are connected to a first annular ring, and
displacement of the first annular ring in an axial direction in the
loading unit moves the plurality of prongs between the recessed
position and the extended position.
4. The surgical stapler as claimed in claim 3, wherein the loading
unit includes a distal end remote from the handle and at least one
aperture in the distal end, the surgical stapler further comprising
a loading tool insertable in the aperture to move the annular ring
in the axial direction.
5. The surgical stapler as claimed in claim 4, wherein the loading
unit includes a plurality of fingers arranged radially in the body,
the fingers having a recessed position within the body for
inserting the body into the prosthetic graft, and an extended
position projecting radially outward from the body for engaging an
end edge of the prosthetic graft to hold the prosthetic graft in
the assembled position on the loading unit.
6. The surgical stapler as claimed in claim 5, wherein the
plurality of fingers are connected to a second annular ring, and
displacement of the second annular ring in the axial direction in
the loading unit moves the plurality of fingers between the
recessed position and the extended position.
7. The surgical stapler as claimed in claim 6, wherein insertion of
the loading tool in the aperture moves both the first and second
annular rings in the axial direction.
8. The surgical stapler as claimed in claim 1, wherein the loading
unit includes a plurality of fingers arranged radially in the body,
the fingers having a recessed position within the body for
inserting the body into the prosthetic graft, and an extended
position projecting radially outward from the body for engaging an
end edge of the prosthetic graft to hold the prosthetic graft in an
assembled position on the loading unit.
9. The surgical stapler as claimed in claim 8, wherein the
plurality of fingers are connected to an annular ring, and
displacement of the annular ring in an axial direction in the
loading unit moves the plurality of fingers between the recessed
position and the extended position.
10. The surgical stapler as claimed in claim 9, wherein the loading
unit includes a distal end remote from the handle and at least one
aperture in the distal end, the surgical stapler further comprising
a loading tool insertable in the aperture to move the annular ring
in the axial direction.
11. The surgical stapler as claimed in claim 1, wherein the
plurality of staples are arranged in a circumferential pattern in
the body of the loading unit.
12. The surgical stapler as claimed in claim 11, wherein the
loading unit extends in an axial direction, and the plurality of
staples are aligned in a plane orthogonal to the axial
direction.
13. The surgical stapler as. claimed in claim 1, further comprising
a control mechanism operable to move the anvil assembly between the
open position and the closed position.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S.
Provisional Patent Application Ser. No. 60/571,738 filed May. 17,
2004, the disclosure of which is hereby incorporated by reference
herein.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to a surgical
stapling system, and more particularly to a system for joining two
tubular structures using surgical staples. Still more particularly,
the present invention relates to an apparatus and method for
stapling together two tubular structures either through an open
surgical procedure or laparoscopically.
[0003] The repair of aortic aneurysms and other aortic defects
typically requires major abdominal surgery in which the defective
segment of the aorta is removed and replaced with a prosthetic
device, such as a synthetic graft. Such procedure ordinarily
requires the graft to be sutured to the end of the sectioned aorta
or to a felt cuff which has been sutured to the aorta. The suturing
of the graft to the aorta or the cuff can be a difficult and
time-consuming process, requiring the patient's aorta to be clamped
shut for extended periods of time.
[0004] There therefore exists a need for an arrangement which will
enable a tubular graft to be attached to the sectioned aorta in a
quick and reliable manner.
SUMMARY OF THE INVENTION
[0005] The present invention addresses these needs.
[0006] The present invention provides a surgical stapler for
joining a tubular prosthetic graft to a body lumen, the surgical
stapler including a handle having a proximal end and a distal end;
a loading unit removably connected to the distal end of the handle,
the loading unit including a body adapted for insertion into the
prosthetic graft; an anvil assembly having an open position and a
closed position, the anvil assembly in the closed position being
spaced around and relatively close to the body of the loading unit,
and the anvil assembly in the open position being spaced relatively
distant from the body of the loading unit; a plurality of staples
arranged in the body of the loading unit for deployment along paths
extending radially outward from the loading unit; a deployment
mechanism operable to urge the plurality of staples outward from
the loading unit along the radial paths; and an actuating mechanism
at the proximal end of the handle and operable to actuate the
deployment mechanism, whereupon the plurality of staples are
simultaneously urged radially outward from the loading unit along
the radial paths.
[0007] The loading unit may include a plurality of prongs arranged
radially in the body, the prongs having a recessed position within
the body for inserting the body into the prosthetic graft, and an
extended position projecting radially outward from the body for
holding the prosthetic graft in an assembled position on the
loading unit.
[0008] The plurality of prongs may be connected to a first annular
ring, and displacement of the first annular ring in an axial
direction in the loading unit may move the plurality of prongs
between the recessed position and the extended position.
[0009] The loading unit may include a distal end remote from the
handle and at least one aperture in the distal end, the surgical
stapler further including a loading tool insertable in the aperture
to move the annular ring in the axial direction.
[0010] The loading unit may further include a plurality of fingers
arranged radially in the body, the fingers having a recessed
position within the body for inserting the body into the prosthetic
graft, and an extended position projecting radially outward from
the body for engaging an end edge of the prosthetic graft to hold
the prosthetic graft in the assembled position on the loading
unit.
[0011] The plurality of fingers may be connected to a second
annular ring, and displacement of the second annular ring in the
axial direction in the loading unit may move the plurality of
fingers between the recessed position and the extended position.
Preferably, insertion of the loading tool in the aperture moves
both the first and second annular rings in the axial direction.
[0012] The plurality of staples may be arranged in a
circumferential pattern in the body of the loading unit. In a
preferred embodiment, the loading unit extends in an axial
direction, and the plurality of staples are aligned in a plane
orthogonal to the axial direction.
[0013] The surgical stapler may further include a control mechanism
operable to move the anvil assembly between the open position and
the closed position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] A more complete appreciation of the subject matter of the
present invention and the various advantages thereof can be
realized by reference to the following detailed description in
which reference is made to the accompanying drawings in which:
[0015] FIG. 1 is a perspective view of a first embodiment of
prosthetic graft for use with the surgical stapling system of the
present invention;
[0016] FIG. 2 is a perspective view of the prosthetic graft of FIG.
1 having optional sutures for closing the side port following
deployment of the graft;
[0017] FIG. 3 is a perspective view of a second embodiment of a
prosthetic graft for use with the surgical stapling system of the
present invention;
[0018] FIG. 4 is a perspective view of a loading unit in accordance
with the present invention;
[0019] FIG. 5 is a front perspective exploded view of the loading
unit shown in FIG. 4;
[0020] FIG. 6 is a rear perspective exploded view of the loading
unit shown in FIG. 4;
[0021] FIG. 7A is a longitudinal view, in partial cross-section of
the loading unit in a state for loading a graft thereto;
[0022] FIG. 7B is the same view as FIG. 7A, but showing the loading
unit in a state for loading a prosthetic graft therein;
[0023] FIG. 7C is the same view as FIG. 7A, but showing the loading
unit with a graft loaded thereon;
[0024] FIG. 8 is an elevational view of the loading unit showing a
prosthetic graft loaded thereon;
[0025] FIG. 9 is a perspective view of a placement wand in
accordance with a first embodiment of the present invention;
[0026] FIG. 10A is cross-sectional view of the handle of the wand
of FIG. 9 in a locked condition;
[0027] FIG. 10B is the same view as FIG. 10A, but showing the wand
handle in an unlocked condition;
[0028] FIG. 11 is a perspective view of a placement wand in
accordance with a second embodiment of the present invention;
[0029] FIG. 12A is a cross-sectional view of the handle of the wand
of FIG. 11 in a locked condition;
[0030] FIG. 12B is the same view as FIG. 12A, but showing the wand
handle in an unlocked condition;
[0031] FIG. 13 is a perspective view of a surgical loop for use in
the present invention;
[0032] FIG. 14A is a cross-sectional perspective view of the distal
end of the surgical loop of FIG. 13 showing the band in an unlocked
condition;
[0033] FIG. 14B is the same view as FIG. 14A, but showing the band
being inserted into the retaining block;
[0034] FIG. 14C is the same view as FIG. 14A, but showing the band
in a locked condition;
[0035] FIG. 15 is a perspective view of a surgical stapling
instrument of the present invention;
[0036] FIG. 16 is a front perspective exploded view of the head of
the surgical stapling instrument shown in FIG. 15;
[0037] FIG. 17 is a longitudinal cross-sectional view of the head
of the surgical stapling instrument with the anvils in the open
condition;
[0038] FIG. 18 is a longitudinal cross-sectional view of the head
of the surgical stapling instrument with the anvils in the closed
condition;
[0039] FIG. 19 is an enlarged cross-sectional view showing the male
and female anvil locating members;
[0040] FIG. 20A is a longitudinal cross-sectional view of one
embodiment of the actuating handle of the surgical stapling
instrument in a condition in which the anvils are in the open
condition and the stapling mechanism is not actuated;
[0041] FIG. 20B is a longitudinal cross-sectional view of the head
of the surgical stapling instrument having a loading unit mounted
thereon, with the anvils of the surgical stapling instrument in the
open condition;
[0042] FIG. 21A is a longitudinal cross-sectional view of the
actuating handle of FIG. 20A in a condition in which the anvils are
in the closed condition and the stapling mechanism is not
actuated;
[0043] FIG. 21B is the same view as FIG. 20B, but showing the
anvils of the surgical stapling instrument in the closed
condition;
[0044] FIG. 22A is a longitudinal cross-sectional view of the
actuating handle of FIG. 20A in a condition in which the anvils are
in the closed condition and the stapling mechanism has been
actuated;
[0045] FIG. 22B is the same view as FIG. 20B, but showing the
loading unit in the position following staple deployment;
[0046] FIG. 23 is a longitudinal cross-sectional view of another
embodiment of the actuating handle of the surgical stapling
instrument in a condition in which the anvils are in the open
condition and the stapling mechanism is not actuated;
[0047] FIG. 24 is a longitudinal cross-sectional view of the
actuating handle of FIG. 23 in a condition in which the anvils are
in the closed condition and the stapling mechanism is not
actuated;
[0048] FIG. 25 is a longitudinal cross-sectional view of the
actuating handle of FIG. 23 in a condition in which the anvils are
in the closed condition and the stapling mechanism has been
actuated;
[0049] FIG. 26 is an elevational view of a sizer in accordance with
the present invention;
[0050] FIG. 27 is a longitudinal cross-sectional view showing the
loading unit and a prosthetic graft assembled to the head of the
surgical stapling instrument prior to staple deployment;
[0051] FIG. 28 is the same view as FIG. 26, but showing partial
deployment of the staples;
[0052] FIG. 29 is the same view as FIG. 26, but showing the staples
in a more advanced state of deployment;
[0053] FIG. 30 is the same view as FIG. 26, but showing the staples
fully deployed;
[0054] FIG. 31 is a partial cross-sectional view showing a deployed
staple joining a graft to an aorta;
[0055] FIG. 32 is a highly schematic perspective view showing a
transected aorta;
[0056] FIG. 33 is a highly schematic perspective view showing the
use of a sizer to measure the transected aorta;
[0057] FIG. 34 is a highly schematic perspective view showing the
use of a wand to position a loading unit and graft in the
transected aorta;
[0058] FIG. 35 is a highly schematic perspective view showing the
use of a surgical loop to hold the loading unit and graft in place
in the aorta;
[0059] FIG. 36 is an end view showing the positioning of the
stapling instrument relative to the surgical loop;
[0060] FIG. 37 is a highly schematic perspective view showing the
use of a stapling instrument to staple the graft to the aorta;
and
[0061] FIG. 38 is a highly schematic perspective view showing a
circumferential line of staples joining the graft to the aorta.
DETAILED DESCRIPTION
[0062] In the detailed description which follows, the features of
the present invention will be described in connection with the
anastomosis of a prosthetic graft to the aorta, such as may be
performed in the repair of an abdominal aortic aneurysm. It will be
appreciated, however, that the various features of the present
invention may be readily utilized to connect a tubular prosthetic
graft to any body lumen. Each of the various components of the
surgical stapling system of the present invention is described in
separate headings below.
Prosthetic Graft
[0063] Referring to FIG. 1, there is illustrated one preferred
embodiment of a prosthetic graft 10 for use in the present
invention. Graft 10 is a hollow generally Y-shaped structure formed
by a tapered main body 12 which branches into two legs 14 and 16.
Legs 14 and 16 may have a generally cylindrical shape with a
substantially uniform diameter from their juncture with main body
12 to their respective free ends. Opposite legs 14 and 16, main
body 12 includes a cuff 18 having a substantially uniform diameter,
the free end of which defines a blood flow inlet on one end of
graft 10, while the free ends of legs 14 and 16 define blood flow
outlets from graft 10.
[0064] A generally cylindrical side port 20 is provided on one side
of main body 12, generally between legs 14 and 16. Side port 20
provides a feature by which graft 10 may be inserted into a patient
and held in place during a stapling procedure. In that regard, side
port 20 preferably projects from graft 10 at an acute angle
relative to legs 14 and 16 to facilitate the insertion of a loading
unit 100 (see FIG. 4) therein. As will be explained below, loading
unit 100 supports graft 10 and holds it in place relative to the
aorta or other tubular body organ so that the graft may be
connected to the body organ by stapling. Optionally, referring to
FIG. 2, side port 20 may be provided with one or more sutures 22
adjacent the connection of the side port to main body 12. Suture 22
may be threaded through side port 20 so as to provide a purse
string tie by which the side port may be quickly and easily closed
following deployment of graft 10. Where graft 10 is not provided
with one or more sutures 22, side port 20 may be closed by
stapling, by a conventional suturing procedure, or by the use of a
hook and loop fastener, such as Velcro brand fastener. Once side
port 20 has been closed, any excess graft material may be removed
by cutting.
[0065] Graft 10 is preferably formed from a biocompatible material
having sufficient strength to withstand the surgical implantation
procedure described more fully below, as well as the blood flow and
other biomechanical forces which will be exerted on the graft. Such
materials may include, for example, polyester materials, such as
DACRON.RTM., polytetrafluoroethylene, expanded
polytetrafluoroethylene, polyester materials coated with
polytetrafluoroethylene, polyurethane, expanded polyurethane and
silicone.
[0066] Graft 10 may be provided in a range of sizes sufficient to
accommodate the arterial morphology which the surgeon is likely to
face in the vast majority of patients. In that regard, graft 10 may
be provided with a cuff 18 having a diameter of approximately 16 m,
18 mm or 20 mm, although grafts 10 having larger or smaller
diameters are also possible.
[0067] A second embodiment of a prosthetic graft 50 for use in the
surgical stapling system of the present invention is shown in FIG.
3. Graft 50 is substantially the same as graft 10 described above.
However, rather than side port 20, graft 50 includes an elongated
flap 52 projecting substantially perpendicularly from main body 12.
Flap 52 may be formed by sewing or otherwise connecting individual
portions of graft material 54 and 56 in opposed relationship along
a longitudinal slit formed in main body 12. Following deployment of
graft 50, flap 52 may be closed by stapling or suturing. However,
since flap 52 projects from main body 12 by a lesser amount than
side port 20, there may be no need to remove any excess material
from the flap after it has been closed.
[0068] It will be appreciated that the surgical stapling system of
the present invention may make use of a graft having neither a side
port 20 nor a flap 52. Rather, a graft having simply a cuff 18 at
one end and a pair of legs 14 and 16 at the other end may be
used.
Loading Unit
[0069] A loading unit 100 for use in connection with the present
invention is shown in FIGS. 4-8. Loading unit 100 has a generally
cylindrical body 102 extending in an axial direction, with a
generally thin cap 104 at a proximal end thereof and a tapered cap
106 at a distal end thereof. As used herein, the term "proximal"
refers to the end of a component or device which is closest to the
actuating handle or surgeon, and the term "distal" refers to the
end of a component or device which is farthest away from the
actuating handle or surgeon. Cap 104 may have portions that
protrude beyond the diameter of body 102 so as to define flanges
105. The tapered portion of cap 106 facilitates the assembly of a
graft 10 onto loading unit 100 at one end, while flanges 105 act as
a stop to prevent the graft from being pushed off the loading unit
at the other end. A pair of fingers 108 projecting from cap 104 in
the axial direction of body 102 but at a spaced distance therefrom
help keep the graft in its assembled position on loading unit 100
and keep the legs 14 and 16 of the graft in a controlled position.
A plurality of apertures 107 formed in cap 104 are sized and
positioned to receive the fingers of a pusher 600 to be described
below in connection with the stapling instrument.
[0070] Referring to the exploded views of FIGS. 5 and 6, loading
unit 100 includes a hollow, generally cylindrical cartridge 110.
Cartridge 110 is open at its proximal end for slidably receiving an
actuator 170, and has an end member 112 at its distal end. End
member 112 has a central aperture 114 and a plurality of radially
projecting slots 116 for receiving elongated fingers 176 provided
on the distal end of actuator 170.
[0071] At its distal end, cartridge 110 mates with a second
cylindrical cartridge 120. Cartridge 120 has a central aperture 122
which aligns with aperture 114 of cartridge 110, and a plurality of
radially extending slots 124, each of which aligns with a
corresponding slot 116 in the distal end of cartridge 110 for
receiving the elongated fingers 176 of actuator 170. A plurality of
projections (not shown) on the proximal surface of cartridge 120
mate with corresponding recesses (not shown) formed in the end
member 112 of cartridge 110 so as to maintain cartridge 120 in
registry with cartridge 110.
[0072] A plurality of staple pushers 130 are arranged between
cartridge 110 and cartridge 120 for radial sliding movement between
an inner staple holding position and an outer staple ejecting
position. The number of staple pushers 130 utilized will depend on
the number of staples to be simultaneously deployed during a
stapling procedure. The preferred embodiment of the invention
described herein includes ten staple pushers 130 for deploying
twenty staples. It will be appreciated, however, that a greater or
lesser number of staple pushers may be utilized depending on the
number of staples to be deployed and physical constraints dictated
by the size and operation of loading unit 100.
[0073] Each staple pusher 130 has a generally U-shaped profile
consisting of first and second legs 132 and 134 connected by an
intermediate portion 136. Intermediate portion 136 has a first
laterally projecting tab 138 which slidably engages in one of a
plurality of recessed channels 140 formed in the end member 112 of
cartridge 110. Recessed channels 140 coincide with radially
projecting slots 116, but are larger in width and length. The
opposite side of intermediate portion 136 has a second laterally
projecting tab 142 which slidably engages in one of radial slots
124 formed in cartridge 120. Tab 142 projects from intermediate
portion 136 adjacent the inner end 144 of staple pusher 130. Tab
138, on the other hand, projects from intermediate portion 136 at a
spaced distance from end 144 of staple pusher 130. A recessed
slanted cam surface 146 is formed in intermediate portion 136
between tabs 138 and 142, the purpose of which will be described
below.
[0074] Prior to a stapling operation, with staple pushers 130 in
their inner staple holding positions, loading unit 100 includes a
plurality of surgical staples 150. Staples 150 are loaded in
loading unit 100 so that the crossmember 152 of each staple rests
against the free end of one of legs 132, 134 of staple pushers 130,
with staple legs 154 and 156 projecting radially outward. More
particularly, the crossmember 152 of each staple rests in an
elongated recess 148 formed in the free ends of the legs 132 and
134 of each staple pusher 130. Further, the legs 156 and 154 of
staples 150 reside within opposed radially extending guide channels
158 and 160, respectively, guide channels 158 being formed in end
member 112 of cartridge 110, and guide channels 160 being formed in
cartridge 120. Recesses 148 locate the staples and hold them in
place with respect to the free ends of legs 132 and 134, while
guide channels 158 and 160 guide the staples as they are deployed
from loading unit 100. It will be appreciated from the foregoing
that a loading unit 100 having ten staple pushers 130, and
therefore twenty legs 132, 134, will be able to simultaneously
deploy twenty staples 150.
[0075] Legs 132, 134 of staple pushers 130 each include a pair of
lateral ribs 162 positioned in linear alignment with recess 148.
Ribs 162 are aligned substantially colinearly with legs 154 and 156
of staples 150 so that, upon outward radial movement of staple
pushers 130, the force exerted by the staple pusher is distributed
along the entire length of crossmember 152, with a portion of the
force being exerted in substantial linear alignment with the staple
legs. As a result, any resistance to this outward movement as the
free ends of staple legs 154 and 156 contact and pierce the aorta
and graft 10 and strike the stapling anvils (to be described below)
will not result in significant distortion to crossmember 152.
[0076] Staple pushers 130 are moved from their inner staple holding
positions to their outer staple ejecting positions by actuator 170.
Actuator 170 has a generally tubular main body 172 with an annular
flange 174 at the proximal end thereof, and a plurality of
elongated fingers 176 at the distal end thereof. Fingers 176 are
sized and shaped to be slidably received in the slots 116 of
cartridge 110 and the slots 124 of cartridge 120. Each of fingers
176 includes a tapered surface 178 which cooperates with the cam
surface 146 of a corresponding staple pusher 130 to move the staple
pusher radially outward during a stapling operation, as will be
described below.
[0077] Actuator 170 is mounted on a tubular shaft 180 for sliding
movement in the axial direction of loading unit 100. Shaft 180 has
an enlarged annular flange 182 at its proximal end to prevent cap
104 from sliding axially beyond the proximal end of the shaft. A
retaining clip 184 is assembled over a pair of transverse slots 186
formed in the main body 172 of actuator 170 and cooperates with an
annular groove 188 formed in shaft 180 to temporarily prevent
actuator 170 from sliding on shaft 180. The spring force of
retaining clip 184 is only sufficient to prevent the unintended
relative movement of actuator 170 on shaft 180 during shipping and
handling of loading unit 100. During a stapling operation, however,
the force exerted axially on actuator 170 is sufficient to overcome
the spring force of retaining clip 184. That is, during a stapling
operation, the axial force exerted on actuator 170 causes retaining
clip 184 to spread open as it is pushed against the side of annular
groove 188 until the retaining clip is pushed out of the groove,
thereby enabling actuator 170 to slide axially along shaft 180. A
pair of cutouts 185 are formed on the opposite sides of shaft 180
near its proximal end, the purpose of which will be discussed
below.
[0078] Between cartridge 120 and cap 106, loading unit 100 includes
an assembly for gripping the distal edge of graft 10 and holding it
in place during shipment of the stapling system of the present
invention and during a stapling procedure. The assembly includes an
external graft retainer 190 having a plurality of fingers 192 which
may be extended radially outward from loading unit 100 to grip the
outer distal edge of graft 10, and an internal graft retainer 220
having a plurality of fingers 222 which may be extended radially
outward from the loading unit to pierce the inner distal edge of
graft 10. Retainers 190 and 220 are assembled over the shaft of an
elongated screw 200 which extends through an aperture in cap 106,
the central apertures in cartridges 110 and 120, and actuator 170,
and which ultimately connects at its proximal end to the distal end
of shaft 180 to hold all of the components of loading unit 100 in
assembled relationship. Screw 200 may be joined to shaft 180 by any
technique, including, for example, threaded engagement.
[0079] External graft retainer 190 includes a generally flat,
circular hub 194 having a central aperture 196 for receiving the
shaft of screw 200. Fingers 192 may be formed integrally with hub
194 and extend in a direction proximally and radially outward
thereof. Each finger 192 terminates in a generally L-shaped tip 198
having a surface 198a extending in a generally radial direction and
a surface 198b extending proximally therefrom in a generally axial
direction. An angled cam surface 202 provided between tip 198 and
hub 194 includes a protruding portion or bump 203 at the end of the
cam surface farthest from tip 198. Retainer 190 is preferably
formed from spring steel or a similar material and shaped so that
fingers 192 will be biased toward their rest positions when
displaced radially outward therefrom.
[0080] A cam ring 208 is mounted to hub 194 of retainer 190 by a
plurality of screws or other known fastening technique, with a
spring member 210 sandwiched therebetween. Cam ring 208 has an
elongated central aperture 212 and a shaped surface 214 along its
outer periphery. More particularly, the outer periphery of cam ring
208 includes a smaller diameter annular surface 208a, a larger
diameter annular surface 208b, and a tapered surface 208c
therebetween, the purpose of which surfaces will be described
below. Spring member 210 has a generally flat body portion 216 and
a pair of tabs 218 bent in a proximal direction. Tabs 218 reside in
an annular channel 201 formed in the shaft of screw 200, thereby
limiting the amount by which retainer 190 may move in the axial
direction.
[0081] Internal graft retainer 220 includes a generally flat
circular hub 224 having an enlarged opening 226. opening 226 has
enlarged regions which receive bosses 240 projecting from the
interior of cap 106. Bosses 240 are undercut so that retainer 220
may be rotated relative to cap 106 to lock it in place on the
interior of the cap.
[0082] Fingers 222 of retainer 220 may be formed integrally with
hub 224 and extend in a direction proximally and radially outward
thereof. Each finger 222 terminates in a needle-like tip or prong
228 which projects radially outward. A radially inward projecting
cam 230 formed on each finger 222 intermediate tip 228 and hub 224
has an angled distal cam surface 230a, a cam surface 230b which
extends generally in the axial direction, and an angled proximal
cam surface 230c. Cam 230 is adapted to cooperate with the shaped
peripheral surface 214 of cam ring 208 as will be described further
below. Retainer 220 is preferably formed from the same spring steel
or similar material as retainer 190 and shaped so that fingers 222
will be biased toward their rest positions when displaced radially
outward therefrom.
[0083] In the assembled condition of loading unit 100, retainers
190 and 220 are positioned relative to one another so that each
finger 192 of retainer 190 lies adjacent a finger 222 of retainer
220. Each pair of fingers 192, 222 resides in one of a plurality of
radial recesses 242 formed in the distal surface of cartridge 120
and continuing in the proximal surface of cap 106. Each recess 242
includes a first surface 242a extending generally in an axial
direction, and a cam surface 242b extending at an angle to surface
242a. The surfaces 242a and 242b of each recess 242 are intended to
interact with the cam surface 202 and bump 203 of the finger 192
residing in that recess, as will be explained further below.
[0084] A guidewire 250 is connected at one end to loading unit 100
and projects outward from the proximal end thereof. Guidewire 250
has an enlarged end 252 formed in a conventional fashion. End 252
is receivable in a slot 254 having an enlarged end 256 formed in
the shaft of screw 200. The guidewire then extends through an axial
bore (not shown) in the shaft of screw 200, through the hollow
center of shaft 180 and out the proximal end of loading unit 100.
The engagement of the enlarged end 252 of guidewire 250 in the
enlarged end 256 of slot 254 locks the guidewire in place and
prevents it from being pulled proximally out from loading unit
100.
[0085] A procedure will now be described for mounting a graft 10
onto loading unit 100, which procedure is typically performed in a
factory prior to shipment of the stapling system of the present
invention. FIG. 7A shows a cross-sectional view of loading unit 100
in an initial state for loading a graft thereto. In this position,
fingers 192 on retainer 190 are positioned in recesses 242 spanning
cartridge 120 and cap 106 so that bumps 203 on fingers 192 lie
distally of the cartridge, i.e., they are not located on any cam
surface. As a result, fingers 192 are positioned so that the tips
198 thereof lie below the outer surface of the loading unit. With
retainer 190 positioned as described, the cam ring 208 will be
positioned axially so that the cams 230 on the fingers 222 of
retainer 220 are proximal of the cam ring, i.e., they are not
supported by any of the surfaces of the cam ring. As a result, the
tips 228 of fingers 222 are positioned below the outer surface of
the loading unit.
[0086] In this initial condition, loading unit 100 may be inserted
into side port 20 of graft 10 until the distal end of cartridge 110
protrudes from cuff 18. With graft 10 being held in this position,
an actuating tool T may be used to advance retainer 190 to the
loading position shown in FIG. 7B. Actuating tool T has a series of
pins P which may be inserted into corresponding apertures 106a in
cap 106. As actuating tool T is moved in the axial direction of
arrow A shown in FIG. 7B, pins P engage the hub 194 of retainer
190, forcing the retainer in the proximal direction. As retainer
190 moves proximally, cam surfaces 202 on fingers 192 engage the
edge of cartridge 120 in the recesses 242, thereby forcing fingers
192 radially outward. Continued movement of retainer 190 will cause
bumps 203 on fingers 192 to travel across cam surface 242a and to
begin traveling up cam surface 242b to the position shown in FIG.
7B, at which the tips 198 of the fingers are spaced outwardly from
the loading unit. The movement of retainer 190 proximally also
causes spring member 210 to move proximally, whereupon spring tabs
218 will enter channel 201 formed in the shaft of screw 200. It
should be noted that channel 201 has a width in the axial direction
which is sufficiently large that spring tabs 218 do not contact the
proximal wall of the channel before fingers 192 have moved radially
outward by a far enough distance.
[0087] The proximal movement of retainer 190 also causes cam ring
208 to move proximally, whereupon the proximal edge of the cam ring
will ride along the cam surfaces of the cams 230 on fingers 222
until cam surfaces 230c slide down tapered surface 208c on the cam
ring and cam surfaces 230b come to rest on smaller diameter annular
surface 208a. As in the initial starting position, the tips 228 of
fingers 222 will be positioned below the outer surface of loading
unit 100.
[0088] With fingers 192 and 222 in these positions, graft 10 can be
positioned so that the free edge of cuff 18 rests against surface
198a and below surface 198b at the tip of each finger 192. At this
point, actuating tool T may be moved in the direction of arrows B
shown in FIG. 7C and removed from loading unit 100. With the
actuating tool T no longer holding retainer 190 in place, the
radially inward biasing force of fingers 192, through the
interaction of bumps 203 with cam surfaces 242b, biases retainer
190 in the distal direction. At the same time, the tapered surface
208c on cam ring 208 will engage the cam surfaces 230c on fingers
222 to push fingers 222 radially outward against the radially
inward biasing force of the fingers. The biasing force exerted by
fingers 192 preferably is deliberately designed to be greater than
the biasing force exerted by fingers 222 so that retainer 190 moves
in the distal direction. optionally, a spring element (not shown)
may be assembled between cam ring 208 and cartridge 120 to assure
that retainer 190 moves in the distal direction upon removal of
actuating tool T from loading unit 100. The distal movement of
retainer 190 continues until spring tabs 218 strike the distal wall
of annular channel 201. Alternatively, where graft 10 has
sufficient strength, retainer 190 may move distally until the
surfaces 198b at the tip of fingers 192 contact the graft,
whereupon the graft prevents further inward movement of the fingers
and, hence, further distal movement of retainer 190.
[0089] In either event, as retainer 190 moves distally, cam ring
208 moves distally with it. This movement causes the cam surfaces
230c on fingers 222 to ride up the tapered surface 208c on cam ring
208, with cam surfaces 230b ultimately coming to rest on larger
diameter annular surface 208b. This action causes fingers 222 to
expand radially outward of loading unit 100 so that the tips 228
thereof pierce graft 10 from the inside. The interaction of the
tips 198 of fingers 192 and the tips 228 of fingers 222 with graft
10 hold the graft securely on loading unit 100. That is, with tabs
218 of spring member 210 abutting the distal wall of annular
channel 201, retainer 190 is prevented from moving further in the
distal direction. Furthermore, the interaction of the bumps 203 on
fingers 192 with cam surfaces 242b prevents retainer 190 from
moving proximally in the axial direction since any such movement
would have to overcome the biasing force of fingers 192. With
retainer 190 unable to move axially in either direction, the tips
198 of fingers 192 and the tips 228 of fingers 222 remain in fixed
positions and hold graft 10 securely in place. An elevational view
of the loading unit 100 having a graft 10 loaded thereon is shown
in FIG. 8.
[0090] In a variant of loading unit 100 described above, rather
than relying upon the relative biasing forces exerted by fingers
192 and 222, or upon an optional spring assembled between cam ring
208 and cartridge 120, the pins P of actuating tool T may be
provided with a feature which engages a corresponding feature in
the hub 194 of retainer 190 so that actuating tool T may be used to
manually pull retainer 190 distally to an appropriate position.
[0091] It will be appreciated that loading unit 100 may be provided
in a series of different diameters which correspond to the
diameters in which graft 10 is provided. Thus, graft 10 and loading
unit 100 are typically provided as a unit, with graft 10 mounted on
a loading unit in condition for ready use by the surgeon.
[0092] Also, loading unit 100 may be formed as a reusable device,
including components formed from spring steel and other relatively
expensive materials. Alternatively, loading unit 100 may be formed
from less costly materials, such as plastic, so as to be disposable
after a single use.
Wand
[0093] FIGS. 9-10 illustrate a placement wand 300 in accordance
with one embodiment of the present invention. Wand 300 is a
lightweight, maneuverable tool used to insert loading unit 100 and
its associated graft into the proper surgical position and to hold
them in place as the graft is temporarily secured to the aorta for
a subsequent stapling procedure. Wand 300 includes a shaft 302
having a substantially straight elongated portion 304 and a distal
end portion 306 which is oriented at an angle relative to elongated
portion 304. End portion 306 may form an angle of between about
90.degree. and about 180.degree. with elongated portion 304. In
preferred embodiments, end portion 306 forms an angle of between
about 105.degree. and about 125.degree. with elongated portion 304,
with an angle of about 115.degree. being most preferred. A bore 308
extending through the entire length of shaft 302 is sized to
receive guidewire 250 as loading unit 100 is assembled to wand
300.
[0094] An attachment mechanism 314 is connected to the distal end
of shaft 302. Attachment mechanism 314 has a cylindrical end
portion 316 having a counterbore sized for receiving the distal end
of shaft 302. A flat may be formed in the counterbore so as to mate
with a corresponding flat formed on the distal end of shaft 302,
thereby defining the proper rotational relationship between
attachment mechanism 314 and shaft 302. Attachment mechanism 314
may be held in assembled relationship on shaft 302 by a set screw
(not shown) or any other known fastening technique.
[0095] Projecting distally from end portion 316 of attachment
mechanism 314 is an elongated finger 320. Finger 320 has a pair of
flat side surfaces 322, a curved upper surface 326 and a flat lower
surface. The shapes of these surfaces coincide with the internal
shape of shaft 180 of loading unit 100 so that the loading unit is
unable to rotate once assembled to wand 300. A bore (not shown)
extending through attachment mechanism 314 aligns with bore 308 in
shaft 302 when these components are assembled together.
[0096] At its proximal end, wand 300 includes an operating handle
330 having first and second handle portions 332 and 334 which may
be assembled together using any conventional technique. Handle 330
may be assembled to the proximal end of shaft 302 by capturing a
reduced diameter portion 336 of shaft 302 between the handle
portions when they are assembled together. A pair of projections
338 and 340 formed in each of handle portions 332 and 334 engage a
pair of grooves 342 and 344, respectively, formed transversely in
shaft 302 to locate shaft 302 in the proper rotational orientation
relative to handle 330 and to prevent the shaft from sliding out of
the handle when in the assembled position. Coiled guidewire tubing
346 is held in the proximal end of handle 330 by the assembly of
handle portions 332 and 334. Guidewire tubing 346 receives the
excess length of guidewire 250 which protrudes out from the
proximal end of wand 300 and holds it in a manageable position.
When wand 300 is removed from loading unit 100, as explained below,
coiled tubing 346 may first be removed from handle 330 by pulling
to expose guidewire 250. Alternatively, guidewire tubing 346 may
remain connected to handle 330, and guidewire 250 may simply be
pulled out from the tubing as wand 300 is removed from loading unit
100.
[0097] Handle 330 includes a locking mechanism 350 operable between
a locked position for engaging guidewire 250 so as to prevent
sliding movement between wand 300 and the guidewire, and an
unlocked position for releasing the wand for movement relative to
the guidewire. In the embodiment shown in FIGS. 9-10, locking
mechanism 350 may operate as a toggle. Thus, locking mechanism 350
may include a trigger lock 352 having a first operating button 354
and a second operating button 356 provided on either side of a
pivot member (not shown) . The ends of the pivot member are held by
handle portions 332 and 334 so that trigger lock 352 is free to
pivot between the locked and unlocked positions. A brake 360 having
a pivot member (not shown) at one end thereof is pivotably mounted
in handle 330 below trigger lock 352, and a friction member 364 is
mounted below brake 360. Friction member 364 is preferably formed
from a soft, resilient material which, when pressed with sufficient
force against guidewire 250, will prevent wand 300 from sliding
relative to the guidewire. In that regard, friction member 364 may
be formed from a resilient plastic, rubber or like material.
Preferably, friction member 364 is formed from silicone rubber, and
more preferably, is formed from a length of silicone rubber tubing.
Brake 360 cooperates with friction member 364 to lock wand 300 to
guidewire 250 in the locked position of locking mechanism 350 and
to release wand 300 for movement relative to guidewire 250 in the
unlocked position of locking mechanism 350.
[0098] More particularly, in the locked condition of locking
mechanism 350, button 354 is in the depressed position shown in
FIG. 10A. In this position, an arcuate locking protrusion 366
formed on trigger lock 352 below its pivot member rests on a raised
flat region 368 on the upper surface of brake 360. As a result,
brake 360 is forced downwardly against friction member 364, forcing
it tightly against guidewire 250 and preventing relative movement
between the guidewire and wand 300. Where friction member 364 has a
tubular structure, the downward force exerted by brake 360 causes
the tubular structure to collapse, thereby engaging guidewire 250
between the opposed inner walls of the tube.
[0099] Depressing button 356 to move trigger lock 352 to the
unlocked position shown in FIG. 10B causes locking protrusion 366
to rotate about its pivot member until it lies over a recessed
region 370 formed in the upper surface of brake 360. With brake 360
no longer held tightly against friction member 364, the resiliency
of the friction member pushes brake 360 upwardly until locking
protrusion 366 rests within recessed region 370. As a result,
friction member 364 is no longer compressed against guidewire 250,
and the guidewire is released for sliding movement relative to wand
300.
[0100] A second embodiment of a placement wand 380 for use with the
present invention is shown in FIGS. 11-12. Wand 380 is
substantially the same as wand 300, but has a locking mechanism 382
which uses a slidable trigger lock 384 rather than the trigger lock
352 which operates in a toggle fashion. Trigger lock 384 slides
between locked and unlocked positions in an elongated cavity 385
formed in first and second handle portions 386 and 388 of operating
handle 390. A locking protrusion 392 projects downwardly from
trigger lock 384 at the proximal end thereof. A brake 394 having a
pivot member (not shown) at one end thereof is pivotally mounted in
handle 390 below locking protrusion 392, and a friction member 398
is mounted below brake 394. Friction member 398 is preferably
formed from the same silicone rubber tubing as described above in
connection with friction member 364 of wand 300.
[0101] In the locked condition of locking mechanism 382, the
trigger lock 384 is slid to the distal position shown in FIG. 12A.
In this position, locking protrusion 392 rests in a shallow
depression formed in a raised region 397 on the upper surface of
brake 394. As a result, brake 394 is forced downwardly against
friction member 398, engaging guidewire 250 and preventing its
movement relative to wand 380.
[0102] Sliding trigger lock 384 in the proximal direction to the
unlocked position shown in FIG. 12B moves locking protrusion 392 to
a position overlying a recessed region 399 formed in the upper
surface of brake 394. The resiliency of friction member 398 thus
pushes brake 394 upwardly until locking protrusion 392 rests within
recessed region 399. As a result, friction member 398 is no longer
compressed against guidewire 250 and the guidewire is released for
sliding movement relative to wand 380.
Surgical Loop
[0103] FIGS. 13-14 illustrate a surgical loop 400 for use in the
present invention. Surgical loop 400 is used to temporarily hold
the cuff 18 of graft 10 in an appropriate position within the
exposed aorta so that a stapling operation may be performed. It
will be appreciated, however, that surgical loop 400 may be used in
any surgical procedure where there is a need to place a clamp
around a tubular or cylindrical structure.
[0104] Surgical loop 400 has a generally straight hollow shaft 402
with a handle 404 provided at a proximal end thereof. A button 406
is mounted in handle 404 for sliding movement in an axial direction
along an elongated slot 408. Within handle 404, button 406 is
connected to the proximal end of an elongated rod 410 which is
arranged for sliding movement within shaft 402.
[0105] At its distal end, shaft 402 is enclosed by an end plug 412
having a through slot 414. Through slot 414 is sized to slidably
receive an elongated flexible band 416. At one end, band 416 is
fixedly connected to the distal end of rod 410, such as by a screw
417 or any other conventional connecting technique. At its other
end, band 416 has a rounded tip 418 and opposed notches 420
defining a narrowed neck spaced from tip 418, the purpose of which
will be described below. Band 416 preferably is wider than it is
thick so as to define a rectangular cross-section which will hold
an annular shape better than the round cross-section of a
conventional suture. Band 416 may be formed from any material
having sufficient flexibility to conform smoothly around loading
unit 100, graft 10 and the aorta, and sufficient tensile strength
to securely hold graft 10 and the aorta in overlapping relationship
during a stapling operation. In that regard, particularly preferred
materials for forming band 416 are nitinol or other shape memory
materials, polypropylene, polyethylene, Mylar.TM. polyester, nylon
and other suitable materials. Nitinol or other shape memory
materials are particularly preferred since they permit band 416 to
be preformed with a curvature that will facilitate the maneuvering
of band 416 around the graft and artery.
[0106] A retaining block 422 is assembled in the distal end of
shaft 402 for sliding movement in the axial direction between end
plug 412 and one or more tangs 424 bent inwardly from shaft 402. A
spring 426 disposed between retaining block 422 and end plug 412
biases the retaining block in the proximal direction against tangs
424.
[0107] Retaining block 422 has an axial bore 428 which is sized and
shaped to receive the rounded tip 418 of band 416. Below bore 428,
retaining block 422 has an axial slot 430 aligned with the through
slot 414 in end plug 412 and sized and shaped to receive band 416
for sliding movement relative to the retaining block. The upper
wall 432 of retaining block 422 has an axial slot 434 which extends
the length of the retaining block and communicates with axial bore
428. A keyhole 436 is formed in the upper wall 432 of retaining
block 422 in a direction transverse to slot 434. Keyhole 436 is
sized to receive tip 418 of band 416 and to permit its insertion
into axial bore 428.
[0108] To operate surgical loop 400, button 406 is initially pushed
in the distal direction to deploy band 416 through the slot 414 in
end plug 412. When formed from a shape memory material, band 416
will form a curved shape so that tip 418 will approach the distal
end of shaft 402. When not formed from a shape memory material,
band 416 may be manually manipulated to place tip 418 near the
distal end of shaft 402.
[0109] Surgical loop 400 may then be operated to capture the tip
418 of band 416. More particularly, button 406 may be pushed
further in the distal direction so that the distal end of rod 410
contacts retaining block 422. Further movement of button 406 in the
distal direction will cause rod 410 to push retaining block 422 in
the distal direction against the biasing force of spring 426 until
the keyhole 436 in retaining block 422 is aligned with an aperture
438 in shaft 402. At this point, tip 418 of band 416 may be
inserted through aperture 438 and keyhole 436 until the tip resides
within the axial bore 428 in retaining block 422 and notches 420
are aligned with the slot 434 in the upper wall 432 of the
retaining block. As button 406 is released, the biasing force of
spring 426 will push retaining block 422 proximally, whereupon
notches 420 will reside in slot 434, keyhole 436 will no longer be
aligned with aperture 438 and tip 418 will be captured within the
bore 428 in the retaining block.
[0110] To tighten band 416 around loading unit 100, graft 10 and
the aorta, button 406 is moved in the proximal direction so as to
draw band 416 into shaft 402. As button 406 is retracted, a
plurality of teeth (not shown) provided on button 406 may engage
with a similar plurality of teeth (not shown) provided on handle
404. The engagement of the teeth on these respective components may
act as a ratchet mechanism enabling button 406 to be retracted, but
blocking it from movement relative to handle 404 in the distal
direction. Therefore, as band 416 is progressively tightened, it
will be locked in place and prevented from loosening at each step
in the tightening process. The teeth on the respective components
may be biased into engagement with one another by a spring (not
shown) interposed between button 406 and handle 404. Thus, by
depressing button 406 to overcome the biasing force of the spring,
the teeth may be separated from one another so that button 406 may
be moved distally to release band 416.
[0111] Rather than employing a band 416 having a rectangular
cross-section, surgical loop 400 may employ a conventional wire
having a round cross-section. In such event, the wire would include
an enlarged feature at its distal end which may be captured and
held within bore 428 in retaining block 422.
Stapling Instrument
[0112] One embodiment of a stapling instrument 500 which attaches
to loading unit 100 and is operable to actuate a stapling procedure
is illustrated in FIGS. 15-22. Instrument 500 includes a hollow
outer shaft 502 having a substantially straight elongated portion
504 and a smoothly curved distal end portion 506 which terminates
at an angle relative to elongated portion 504. End portion 506 may
terminate at an angle of between about 90.degree. and about
180.degree. relative to elongated portion 504. Preferably, end
portion 506 terminates an angle of between about 105.degree. and
about 125.degree. relative to elongated portion 504, with an angle
of about 115.degree. being most preferred. An anvil assembly 510 is
provided at the distal end of shaft 502, while a handle 512 is
provided at the proximal end thereof. optionally, a bushing 508
having a flange 509 at a proximal end thereof may be assembled over
a reduced diameter portion at the proximal end of outer shaft 502
and held in place thereon by a retaining ring 507 so as to be
rotatable relative to the shaft. Handle 512 may be assembled to
shaft 502 by capturing flange 509 between handle portions 511 and
513 when they are assembled together. By connecting handle 512 to
bushing 508, the handle is able to rotate without binding relative
to the remainder of instrument 500, and therefore may be maneuvered
by the surgeon to an appropriate position to effect a stapling
procedure.
[0113] Referring specifically to FIG. 16, anvil assembly 510
includes a generally hollow anvil hub 514 having a cylindrical side
wall 516 to which right anvil 518a, left anvil 518b, and center
anvil 518c are pivotably mounted. Each anvil includes an elongated
arm 520 having a dog-leg configuration with a pair of laterally
projecting guide pins 522 at the proximal end thereof and an
arcuate-shaped bracket 524 at the distal end thereof. An anvil
insert 526 having a plurality of spaced staple returns 528 may be
mounted to each bracket 524. Instrument 500 has a total of twenty
staple returns 528, six each on right anvil 518a and left anvil
518b, and eight on center anvil 518c which has a bracket 524 with a
slightly larger arcuate length. Each staple return has depressions
for guiding the free ends of a staple 150 into a bent
configuration. Alternatively, staple return 528 may be formed
directly in brackets 524.
[0114] The brackets 524 on the ends of anvils 518a, 518b and 518c
each define an arc such that, in the closed position of anvil
assembly 510, these brackets collectively define a complete circle.
Each bracket 524 includes a male locating member 530 at one end
thereof and a female locating member 532 at the opposite end
thereof, the male and female locating members on adjacent brackets
524 engaging with one another in the closed position of anvil
assembly 510 so as to properly locate and align staple returns 528
relative to one another.
[0115] In a preferred embodiment hereof shown in FIG. 19, male
locating member 530 may have a conical portion 530a with a rounded
tip and a substantially flat ring 530b formed around its base.
Female locating member 532 may have a tapered recess 532a shaped to
mate with the tapered walls of portion 530a, and a substantially
flat ring 532b formed around recess 532a. An extended bore 532c may
be formed at the bottom of recess 532a. When anvil assembly 510 is
closed, conical portion 530a fits within recess 532a and surfaces
530b and 532b are pressed tightly against one another. The small
area of surfaces 530b and 532b, combined with the high compressive
force developed on the closing of the anvils, cause any tissue
which may be captured between surfaces 530b and 532b to be
pulverized. Furthermore, any miscellaneous tissue which may be
captured between conical portion 530a and tapered recess 532a upon
the closing of anvil assembly 510 may be pushed into the extended
bore 532c at the bottom of recess 532a. Hence, this structure of
male locating member 530 and female locating member 532 helps
assure that anvils 518a, 518b and 518c achieve a fully closed
condition and are not prevented from doing so by any extraneous
tissue which may be present during the surgical procedure.
[0116] Anvils 518a, 518b and 518c are pivotably mounted to anvil
hub 514 by a series of yokes 534 formed at spaced distances on the
outer surface of side wall 516. Each yoke 534 includes a pair of
supports 536 which project beyond the distal end 538 of anvil hub
514, and which are spaced apart so as to receive one of anvil arms
520 therebetween. A barrel nut 540 may be inserted through a pair
of axially aligned apertures 542 formed in supports 536 and through
an aperture 544 provided at the dog leg in an anvil arm 520 and
mate with a screw 541 for holding the anvil in assembled
relationship to anvil hub 514. Alternatively, anvils 518 may be
held to yokes 534 through any other technique allowing pivoting of
the anvil arms, such as through a pivot pin or the threaded
engagement of one end of a shoulder bolt with threads formed in one
of apertures 542. Access openings 546 are formed in side wall 516
in the spaces between each pair of supports 536 in a yoke 534, the
access openings continuing radially inward by a predetermined
amount in the distal end 538 of anvil hub 514. Access openings 546
enable the proximal ends of anvil arms 520 to project into the
interior of anvil hub 514 and provide clearance for the movement of
anvils 518 between open and closed positions. The distal end 538 of
anvil hub 514 includes a central aperture 545 having curved top and
bottom surfaces and flat side surfaces, and a series of apertures
548 arranged substantially symmetrically around central aperture
545 for slidably receiving the fingers of a pusher 600, the purpose
of which will be described below.
[0117] A cam element 550 is slidably assembled in the open proximal
end of anvil hub 514. Cam element 550 has a generally cylindrical
structure with a series of ribs 554 projecting radially outward
therefrom. Ribs 554 are oriented in the axial direction of anvil
assembly 510 and engage in similarly oriented channels (not shown)
formed in the interior of anvil hub 514. Each channel is positioned
so as to be radially inward of a corresponding yoke 534.
[0118] Ribs 554 are formed with a central slot 558 having a width
sufficient to receive the proximal end of an anvil arm 520, and an
undercut 560 on each side of the slot for receiving the guide pins
522 on anvils 518. The bottom surface of each slot 558, including
undercut portions 560, defines a tapered cam surface 562 so that
axial movement of cam element 550 relative to anvil hub 514 causes
anvils 518 to move between the open and closed positions. An arm
564 projects axially from the proximal end of cam element 550. Arm
564 has a transverse aperture 566 at its free end for connection to
a drive mechanism for effecting axial movement of cam element 550,
as will be explained below.
[0119] Cam element 550 includes a central bore 568 having flat top
and bottom surfaces and curved side surfaces, and a generally
cylindrical counterbore 570 extending inwardly from the distal end
of the cam element to an end wall 572. A series of through openings
574, similar in size and shape to apertures 548 in anvil hub 514,
are arranged substantially symmetrically around central opening 568
for slidably receiving the fingers of pusher 600.
[0120] An anvil hub shaft 576 is mounted in anvil assembly 510
between anvil hub 514 and cam element 550. Shaft 576 has a large
intermediate portion 578 having a substantially cylindrical
cross-section, and a proximal end portion 580 which is smaller in
cross-section so as to define a step 582 therebetween. Similarly,
shaft 576 has a distal end portion 584 which is smaller in
cross-section than intermediate portion 578 so as to define a step
586 therebetween. The intermediate portion 578 of shaft 576 has
similar recesses 588 formed in its upper and lower surfaces, each
of which is sized and shaped to receive a catch member 590. Catch
members 590 have a protruding transverse rib 591 so that the catch
members rest in recesses 588 in a see-saw fashion. A spring catch
592 in the form of a split ring may be assembled in an annular
groove 594 formed by the circumferential alignment of groove
portions in the intermediate portion 578 of shaft 576 and in each
of catch members 590. The assembly of spring catch 592 around the
catch members 590 and the intermediate portion 578 of shaft 576
holds the catch members in assembled relationship to shaft 576 so
that the distal ends of the catch members are biased outwardly,
while permitting the distal ends of the catch members to pivot
inwardly upon the application of a radially inward compressive
force thereto. At their distal ends, catch members 590 each have a
radially projecting prong 596 having a sharply tapered distal
surface and a slightly tapered proximal catch surface. Prongs 596
secure loading unit 100 to instrument 500, as will be explained
below.
[0121] The distal end portion 584 of shaft 576 has a shape similar
to that of the elongated finger 320 at the end of wand 300. That
is, the distal end portion 584 of shaft 576 has flat side and lower
surfaces and a curved upper surface for mating engagement within
shaft 180 of loading unit 100. An axial bore 599 is provided along
the length of shaft 576 for receiving guidewire 250, as will be
explained below.
[0122] Shaft 576 is assembled in anvil hub 514 so that the distal
end portion 584 of shaft 576 extends through the central aperture
545 in the anvil hub, with step 586 abutting the inside wall of the
distal end 538 of the anvil hub adjacent aperture 545. The shape of
the aperture 545 in anvil hub 514 assures that the anvil hub is
assembled in the proper orientation on shaft 576 and is unable to
rotate once assembled thereon. In this assembled position, the
distal end portion 584 of shaft 576 extends outwardly from anvil
hub 514, as do the radially projecting prongs 596 on catch members
590.
[0123] Cam element 550 is assembled in anvil hub 514 so as to
capture the intermediate portion 578 of shaft 576 therebetween.
That is, cam element 550 is assembled over the proximal end portion
580 of shaft 576 until the end wall 572. of counterbore 570 is
engaged with step 582 on shaft 576. The corresponding shapes of the
proximal end portion 580 of shaft 576 and the central bore 568 in
cam element 550 assures that these elements are assembled in the
proper orientation and that the cam element is unable to rotate
once assembled on the shaft.
[0124] A pusher 600 having a disk-shaped base member 602 and a
plurality of axially extending fingers 604 is assembled in anvil
assembly 510 so that fingers 604 extend through openings 574 in cam
element 550 and apertures 548 in anvil hub 514. Fingers 604 are of
a sufficient length that when pusher 600 is displaced fully in the
distal direction, the free ends of fingers 604 protrude outwardly
from the distal end 538 of anvil hub 514 and into a loading unit
100 mounted on instrument 500. As will be explained below, pusher
600 acts on actuator 170 to deploy staples 150 during a stapling
operation. A link 606 having a transverse aperture 608 is connected
to the proximal end of base member 602 for joining pusher 600 to a
drive mechanism for effecting axial movement of the pusher.
[0125] Anvils 518 may be moved between the open and closed
positions by an adjustment knob 610 provided at the handle end of
instrument 500. Adjustment knob 610 actuates a drive mechanism
which transfers rotational movement of knob 610 into axial movement
of cam element 550, thereby displacing anvils 518. Referring to
FIGS. 17-22, the drive mechanism may include an elongated tube 612
slidably disposed within the hollow shaft 502 of instrument 500. At
its distal end, tube 612 may be connected to a link coupler 614
using any conventional arrangement. In a preferred arrangement, the
distal end of tube 612 fits within a bore formed in the proximal
end of link coupler 614. These elements may be held together by any
suitable means, including by sliding a retaining ring (not shown)
into a slot 616 formed transversely in link coupler 614 and
engaging it in an annular groove formed adjacent to the distal end
of tube 612.
[0126] Link coupler 614 may be joined to arm 564 on cam element 550
by a plurality of links 620. A pair of track inserts 622 assembled
in the opposite sides of curved distal end portion 506 of shaft 502
may define first and second pairs of laterally spaced guide tracks
624 and 626. Links 620 may ride in guide tracks 626 so that any
axial movement of tube 612 is transferred along the curved portion
of shaft 502 to cam element 550. Links 620 may take any form
capable of transmitting the compressive force exerted by tube 612
and link coupler 614 to cam element 550 as anvil assembly 510 is
placed in a closed condition, and capable of transmitting the
tensile force from tube 612 and link coupler 614 to cam element 550
as tube 612 is retracted to place anvil assembly 510 in an open
condition. Thus, links 620 may consist of individual links joined
together in a conventional fashion, or may be in the form of a
solid band having periodic thinned sections defining a plurality of
living hinges. Alternatively, links 620 may not be links at all,
but may be a solid band having the requisite compressive and
tensile strength, while at the same time having sufficient
flexibility to bend smoothly and uniformly along the curved portion
of shaft 502.
[0127] At its proximal end, tube 612 may be connected to a coupling
element 628. In a preferred embodiment, the proximal end of tube
612 may be inserted into a bore formed in the distal end of
coupling element 628, and these elements may be held together in
the same manner as tube 612 and link coupler 614, that is, by
sliding a retaining ring (not shown) into a slot 630 formed
transversely in coupling element 628 and engaging it in an annular
groove formed adjacent to the proximal end of tube 612.
Alternatively, the distal end of tube 612 may be joined to link
coupler 614 and the proximal end of tube 612 may be joined to
coupling element 628 by any other known connection techniques.
Coupling element 628 may have a pair of elongated bosses (not
shown) extending in the axial direction on either side of the
coupling element. Each of the bosses may be slidably held in an
elongated slot provided in each of handle portions 511 and 513. The
elongated slots have a predetermined length so as to define the
extent of axial travel of coupling element 628.
[0128] At its proximal end, coupling element 628 may be threadedly
engaged with a shaft 642. Shaft 642 has a stepped structure so as
to define an intermediate portion 644 which is smaller in diameter
than a threaded distal portion 646 and larger in diameter than a
proximal portion 648. A bushing 650 may be assembled over
intermediate portion 644 and may be held in place by the step
between the intermediate portion 644 and distal portion 646 of
shaft 642 and a retaining ring 652 assembled in an annular groove
formed in the intermediate portion 644 proximally of the bushing.
The outer circumference of bushing 650 may be formed with an
annular groove 654 which enables the bushing to be captured in a
circular opening formed in the proximal end of handle 512 when
handle portions 511 and 513 are assembled together.
[0129] Adjustment knob 610 has an internal elongated annular boss
656 for receiving the proximal portion 648 of shaft 642. A pair of
diametrically opposed teeth 658 formed on the free end of boss 656
may engage recesses 660 formed in the intermediate portion 644 of
shaft 642 so that any rotational movement of knob 610 results in a
corresponding rotation of shaft 642. A barrel nut 662 engages a
threaded portion 664 formed on the proximal portion 648 of shaft
642 so as to hold knob 610 in assembled relationship to the shaft.
Barrel nut 662 resides in a counterbore 666 formed in the proximal
end of knob 610 so that it does protrude outwardly from the
knob.
[0130] Optionally, a conventional clutch mechanism (not shown) may
be provided between knob 610 and shaft 642 to prevent the
overloading of anvil assembly 510. Thus, once a threshold to the
further closure of anvils 518a, 518b and 518c has been met (either
because the anvils are fully closed or because there is interfering
tissue), the clutch mechanism will enable knob 610 to rotate
without further movement of the anvils, thereby preventing damage
to instrument 500 or damage to tissue from the closing anvils.
[0131] Handle 512 of instrument 500 is further provided with a
trigger mechanism 670 for actuating a stapling operation. Referring
to FIGS. 20A, 21A and 22A, trigger mechanism 670 may include a
trigger 672 pivotably mounted between handle portions 511 and 513
by a pivot pin 674. Trigger 672 has a generally hollow, molded
construction including a pair of spaced side walls 676. Trigger
mechanism 670 may further include a linkage assembly 680 including
a pair of links 682 and 684 joined together by a pivot pin 686. One
end 688 of linkage assembly 680 is pivotably held in a fixed
position between handle portions 511 and 513 by a pivot pin 690.
The opposite end 692 of linkage assembly 680 is pivotably joined to
a coupling element 694. A spring 696 connected between links 682
and 684 bias linkage assembly 680 to the rest position shown in
FIG. 20A. In this rest position, the distal end of link 682 is
relatively close to the proximal end of link 684, such that the
links form a relatively small angle therebetween. Furthermore, an
apex 698 defined at the connection of link 682 to link 684 is
biased against an engagement surface 700 formed between the side
walls 676 of trigger 672.
[0132] An elongated tube 702 slidably disposed within outer shaft
502 of instrument 500 and over tube 612 may be connected at its
proximal end to coupling element 694. More particularly, the
proximal end of tube 702 may be inserted in a bore formed in the
distal end of coupling element 694. This assembly may be maintained
in the same manner as the assembly of tube 612 to link coupler 614,
that is, by sliding a retaining ring (not shown) into a slot 703
formed transversely in coupling element 694 and engaging it in an
annular groove formed adjacent to the proximal end of tube 702. At
its distal end, tube 702 may be connected to a coupling link 704.
In a preferred arrangement, the distal end of tube 702 may be
inserted in a bore formed in the proximal end of coupling link 704
and may be held in assembled relationship therein in the same
fashion as the other tube/coupler connections described above,
namely, by sliding a retaining ring (not shown) into a slot 706
formed transversely in coupling link 704 and engaging it in an
annular groove formed adjacent to the distal end of tube 702.
Alternatively, any other known connection techniques may be used
both to join the distal end of tube 702 to coupling link 704, and
to join the proximal end of tube 702 to coupling element 694.
Coupling link 704 preferably is assembled over tube 612 and
proximally of link coupler 614 so as to not interfere with the
axial movement thereof, and may be joined to link 606 on pusher 600
by a plurality of links 708. Links 708 may ride in laterally spaced
guide tracks 624 formed in track inserts 622 so that any axial
movement of tube 702 is transferred along the curved portion of
shaft 502 to pusher 600. Links 708 may have any of the structures
described above in connection with links 620. Moreover, links 708
may have the same structure as links 620 or a structure different
therefrom.
[0133] As will be appreciated from the foregoing description,
trigger mechanism 670 may be actuated by pressing trigger 672
toward handle 512. This movement of trigger 672 will cause
engagement surface 700 to push against the apex 698 of linkage
assembly 680, thereby causing the angle between links 682 and 684
to be increased against the biasing force of spring 696. Since the
end 688. of linkage assembly 680 is fixed relative to handle 512,
the increased angle between links 682 and 684 will cause the other
end 692 of linkage assembly 680 to move axially in the distal
direction. This axial movement will be transferred through coupling
element 694, tube 702, coupling link 704 and links 708 to pusher
600, resulting in the movement of the fingers 604 of the pusher
into loading unit 100 and the resultant deployment of staples 150.
Following the deployment of staples 150, the biasing force of
spring 696 will cause trigger 672 to return to its rest position as
the compressive force is released therefrom.
[0134] Instrument 500 may further include a guidewire tube 709
which is positioned within tube 612. At its .distal end, guidewire
tube 709 protrudes out from tube 612 and has a curved portion whose
distal end is inserted in a counterbore formed in the proximal end
of anvil hub shaft 576. At its proximal end, guidewire tube 709
extends out from tube 612, through coupling element 628 and into
shaft 642. Guidewire tube 709 provides an uninterrupted channel for
guidewire 250 from loading unit 100 through instrument 500.
[0135] To prevent the premature accidental deployment of staples
150, trigger mechanism 670 may be provided with a safety 710.
Safety 710 may be in the form of an elongated pin (not shown)
having a radially projecting tab 714 formed with an aperture 716. A
shaft (not shown) may be inserted through aperture 716 to mount
safety 710 for sliding movement in a transverse direction between
handle portions 511 and. 513. A first spring (not shown) mounted on
the shaft between tab 714 and handle portion 511, and a second
spring (not shown) mounted on the shaft between tab 714 and handle
portion 513 bias safety 710 to a rest position which is in a
substantially central location between the handle portions. In this
rest position, one end of the elongated pin projects outwardly
through an aperture in handle portion 511 to define a first button,
and the other end of the elongated pin projects outwardly through
an aperture in handle portion 513 to define a second button. With
the ends of the elongated pin and the shaft constrained from
movement by handle portions 511 and 513, safety 710 is prevented
from moving pivotably relative to handle 512, but is free to move
transversely with respect to the handle. Safety 710 further
includes a pair of tangs 732 which, in the rest position of the
safety, align with and engage notches 734 formed in the side walls
676, respectively, of trigger 672. Such engagement prevents trigger
672 from being depressed to actuate a stapling operation. Pressing
either the first or the second button toward handle 512 moves tangs
732 out of alignment with side walls 676 of trigger 672, thereby
clearing the path for the trigger to be depressed relative to
handle 512 so that a stapling operation can be performed.
[0136] A second embodiment of a handle and trigger mechanism for
use with a stapling instrument 800 in accordance with the present
invention is shown in FIGS. 23-25. Stapling instrument 800 is
substantially the same as stapling instrument 500 described above,
with the exception of the handle and the trigger mechanism used to
actuate a stapling procedure. Thus, referring to FIG. 23, the
trigger mechanism 802 of instrument 800 includes a trigger 804
having an elongated grasping portion 806 spaced from handle 808,
and a drive portion 810 projecting laterally from one end of the
grasping portion so as to define a generally L-shaped
configuration. Trigger 804 is mounted between portions 812 of
handle 808 for pivoting movement about a pivot pin 816 disposed at
the intersection of grasping portion 806 and drive portion 810.
[0137] Instrument 800 includes the same tube 702, coupling link 704
and links 708 as instrument 500. However, the structure at the
proximal end of tube 702 differs from that in instrument 500. More
particularly, the proximal end of tube 702 may be connected to a
coupling element 818 in any conventional manner, including that by
which tube 612 is connected to coupling element 628 at its proximal
end. Coupling element 818 may be assembled on tube 612 for sliding
movement in the axial direction of the tube. A biasing spring 820
may be assembled over tube 702 between the distal end of coupling
element 818 and an annular surface 822 formed transversely in
handle 808. Coupling element 818 may have a pair of elongated
bosses (not shown) extending in the axial direction on either side
of the coupling element. Each of these bosses may be slidably held
in an elongated slot (not shown) provided in each of handle
portions 812. The elongated slots have a predetermined length so as
to define the extent of axial travel of coupling element 818.
[0138] Drive portion 810 of trigger 804 may be formed with a pair
of spaced walls 828 at the free end thereof. Each of walls 828 may
include a curved cam surface 830 projecting in a distal direction
therefrom. In the assembled position of trigger mechanism 802,
walls 828 reside on either side of tube 612 with cam surfaces 830
contacting the proximal end of coupling element 818. In the rest
position of trigger mechanism 802, shown in FIG. 23, the force
exerted by spring 820 biases coupling element 818 in the proximal
direction, thereby pivoting the grasping portion 806 of trigger 804
away from handle 808. Trigger mechanism 802 may be actuated by
squeezing the grasping portion 806 of trigger 804 toward handle
808. The counterclockwise movement of trigger 804 (as shown in FIG.
25) will cause the drive portion 810 of the trigger to exert a
force on coupling element 818 through cam surfaces 830, driving
coupling element 818 in the distal direction against the biasing
force of spring 820. This axial movement of coupling element 818
will be transferred through tube 702, coupling link 704 and links
708 to pusher 600, thereby resulting in the deployment of staples
150 as pusher fingers 604 are driven into loading unit 100.
Following deployment of staples 150, spring 820 will again bias
coupling element 818 proximally to return trigger 804 to its rest
position once the compressive force has been released
therefrom.
[0139] Instrument 800 may further include a safety 840 to prevent
the premature accidental deployment of staples 150. Safety 840 may
be pivotably connected between handle portions 812 by a pivot pin
842 so that safety 840 is positioned between handle 808 and the
grasping portion 806 of trigger 804. At its free end, safety 840
has a recess 844 sized to receive the grasping portion 806 of
trigger 804. Recess 844 may include a resilient member 846 adapted
to engage within a shallow recess 848 in grasping portion 806 in
the locked condition of trigger mechanism 802. In a preferred
embodiment, resilient member 846 may be in the form of an S-shaped
member integrally molded with safety 840. Resilient member 846
causes safety 840 to fit tightly between handle 808 and grasping
portion 806 in the locked condition. Such engagement prevents
trigger 804 from being depressed to actuate a stapling operation.
Pivoting safety 840 away from grasping portion 806, however,
releases trigger 804 for movement toward handle 808 to actuate a
stapling operation.
Sizer
[0140] FIG. 26 depicts a sizer 900 for use in the present
invention. Sizer 900 has several functions, including (1) measuring
the diameter of the aorta so that a graft 10 of a proper size may
be connected thereto, (2) assuring that there is an adequate amount
of transected aorta between the surgical clamp on the aorta and the
point of transection for connecting graft 10 using the surgical
stapling system of the present invention, and (3) identifying
approximately where the staple line will be located on the aorta
relative to the point of transection so that the surgeon can be
sure that the staples will penetrate healthy aortic tissue.
[0141] Sizer 900 includes a shaft 902 having a substantially
straight elongated portion 904 and a distal end portion 906 which
is oriented at an angle relative to elongated portion 904. End
portion 906 may form an angle of between about 90.degree. and about
180.degree. with elongated portion 904. In preferred embodiments,
end portion 906 forms an angle of between about 105.degree. and
about 125.degree. with elongated portion 904, with an angle of
about 115.degree. being most preferred.
[0142] A handle 908 is provided at the proximal end of shaft 902,
and a measuring bulb 910 is provided at the distal end of the
shaft. Measuring bulb 910 has a cylindrical central portion 912
with a generally frusto-conical portion 914 formed on the distal
end thereof and another generally frusto-conical portion 916 formed
on the proximal end thereof adjacent shaft 902. The frusto-conical
shape of portions 914 and 916 facilitate the insertion and removal
of sizer 900 through a surgical opening, as well as the insertion
of sizer 900 into a transected aorta.
[0143] As shown in FIG. 26, bulb 910 has a diameter D at central
portion 912, and a length L from the proximal end of central
portion 912 to the distal tip 918 of the bulb. The diameter D is
used to select a graft 10 of an appropriate size for attachment to
the aorta. Thus, in a typical arrangement, a plurality of sizers
900 will be available, each with a bulb 910 having a different
diameter D. Typically, bulbs 910 are provided having nominal
diameters of approximately 16 mm, 18 mm and 20 mm so as to
accommodate the different sizes of aortas a surgeon may ordinarily
encounter. If the bulb 910 of a sizer 900 fits too loosely within
the transected end of the aorta, the selected sizer is too small,
and a sizer having a larger diameter D should be tried. On the
other hand, if the bulb 910 of a sizer 900 does not fit into the
transected end of the aorta, the selected sizer is too large, and a
sizer having a smaller diameter D should be tried. The proper size
is indicated when the bulb 910 fits easily within the transected
aorta without excess play.
[0144] The length L dimension of bulb 910 is used to determine
whether there is an adequate amount of transected aorta available
between the surgical clamp on the aorta and the point of
transection to perform a stapling procedure. Thus, if the bulb 910
of a sizer 900 can be inserted into the transected aorta so that
the entirety of central portion 912 lies within the aorta, the
length of aorta available will be sufficient to perform a stapling
procedure. However, if a length of central portion 912 remains
exposed when bulb 910 has been inserted fully within the transected
aorta (i.e., until the surgical clamp prevents further insertion of
the bulb), there will not be a sufficient length of aorta available
to perform the stapling procedure. In such event, the surgical
clamp may be moved farther away from the point of transection to
make more of the aorta available. If that is not possible, a
conventional graft may be attached to the aorta using a
conventional suturing technique. Since the length of aorta
available for a stapling procedure is independent of the diameter
of the aorta, the length L is the same for each of bulbs 910,
regardless of their diameters.
[0145] Bulb 910 is provided with a circumferential recess 920 in
central portion 912. Recess 920 is located in the length direction
of the bulb so as to indicate the position at which the
circumferential line of staples will be deployed. Hence, a surgeon
may position bulb 910 of sizer 900 adjacent the aorta prior to
transecting same to ensure that the staples will be deployed in
healthy aortic tissue relative to the point of transection.
Operation
[0146] The use of the surgical stapling system of the present
invention to attach a graft to a transected aorta will be now be
described with reference to FIGS. 27-38. The surgical stapling
system may be provided in the form of one or more kits--a first kit
consisting of a series of sizers 900 having different diameters; a
second kit consisting of a stapling instrument 500 and a surgical
loop 400; and a third kit consisting of a graft 10, a loading unit
100, and a wand 300. Each of the kits may include ancillary tools
and materials which may be needed to perform a stapling procedure.
In the third kit, the graft 10 may be preloaded onto the loading
unit 100, which, in turn, may be assembled to the distal end of the
wand 300. The size of the graft and the loading unit may differ
from kit to kit depending upon the size of the aorta to be
repaired. The various components may be separated into multiple
kits having the components noted above based on different levels of
clean room requirements which must be adhered to during manufacture
and packaging. Each of the components may be designed to be
disposable after their use to perform a single surgical
procedure.
[0147] As a first step of the procedure, the surgeon may position a
sizer 900 adjacent an aorta A to be repaired so as to determine,
based on the anticipated point of transection, whether there will
be healthy aortic tissue at the projected circumferential stapling
line indicated by the circumferential recess 920 in the sizer. The
surgeon may then clamp the aorta and form a transection as shown in
FIG. 32. As shown in FIG. 33, sizer 900 of an appropriate diameter
is then inserted into the transected aorta to determine the
approximate diameter of the aorta as well as whether a sufficient
length of transected aorta is available between the transection and
the clamp to perform a stapling procedure.
[0148] Once the approximate size of the aorta has been determined,
and assuming the availability of a sufficient length of transected
aorta, the surgeon uses wand 300 to insert a loading unit 100 and
its associated graft 10 of the proper diameter into the transected
aorta. Referring to FIG. 34, graft 10 is inserted until the cuff 18
of the graft is positioned entirely within the aorta. At this
point, surgical loop 400 is used to deploy band 416 around the
aorta and the underlying graft 10 and loading unit 100. Surgical
loop 400 may be positioned so that the shaft 402 thereof is
oriented at either the two o'clock or ten o'clock position, as can
be seen in FIG. 36, so that the surgical loop does not interfere
with either the assembly of instrument 500 to loading unit 100 or
the closing of the anvils 518 of the instrument. As shown in FIG.
35, surgical loop 400 is used to deploy band 416 so that the band
is positioned around the aorta in a region adjacent the point of
transection. Tightening band 416 around the aorta holds the aorta
and graft 10 in fixed overlapping relationship around loading unit
100.
[0149] Once band 416 has been placed around the aorta and
tightened, wand 300 may be disconnected from loading unit 100. This
may be accomplished by first pulling guidewire tubing 346 from the
proximal end of handle 330 and off of guidewire 250, and then
depressing button 356 on handle 330 to place locking mechanism 350
in the unlocked condition. As a result, wand 300 may be pulled
proximally along guidewire 250, whereupon finger 320 will be drawn
out from shaft 180 of the loading unit 100. Wand 300 may then be
removed entirely from guidewire 250. Alternatively, wand 300 may be
removed from guidewire 250 with guidewire tubing 346 attached
thereto.
[0150] As the next step, the surgeon may assemble instrument 500 to
loading unit 100 as shown in FIG. 37. With anvils 518 in the opened
condition (by appropriate rotation of knob 610), guidewire 250 may
be inserted into the axial bore 599 in shaft 576, through guidewire
tube 709 and out the proximal end of instrument 500. Instrument 500
may then be slid along guidewire 250 until the distal end of shaft
576 is inserted into shaft 180 of loading unit 100. As instrument
500 is advanced, the prongs 596 projecting radially outward from
shaft 576 will encounter the cutouts 185 formed on the opposite
sides of shaft 180. As they are received in cutouts 185, prongs 596
will be biased radially outward and snap into place, thereby
creating an audible click to assure that instrument 500 is fully
assembled to loading unit 100. As a further assurance of complete
assembly, guidewire 250 may be formed with a colored band or other
marker which will be visible outside of handle 512 when instrument
500 has been assembled fully to loading unit 100.
[0151] Anvil assembly 510 may then be placed in the closed
condition shown in FIG. 18 by rotating adjustment knob 610. As
adjustment knob 610 is rotated, shaft 642 is rotated in the same
direction through the engagement of teeth 658 on the knob with
recesses 660 on the shaft. The rotation of shaft 642 causes
coupling element 628 to move distally as a result of its threaded
engagement with shaft 642. The distal movement of coupling element
628 pushes tube 612 distally, and with it link coupler 614 and
links 620. As a result of this distal movement, cam element 550 is
also moved in the distal direction. The relative movement of cam
element 550 into anvil bracket 514 causes the guide pins 522 on
anvils 518 to move outwardly along tapered cam surface 562,
resulting in the inward movement of brackets 524 at the distal ends
of the anvils. Knob 610 is rotated until anvil assembly 510 is in
the fully closed condition with brackets 524 defining a complete
circle.
[0152] With anvil assembly 510 fully closed, trigger mechanism 670
may be actuated to deploy staples 150. As a first step, one of
buttons 726 and 730 is depressed to release safety 710 from trigger
672. Trigger 672 may then be squeezed toward handle 512, whereupon
engagement surface 700 within trigger 672 pushes against the apex
698 of linkage assembly 680. This movement causes the end 692 of
linkage assembly 680 to move axially in the distal direction,
thereby moving coupling element 694, tube 702, coupling link 704
and links 708 distally. The distal movement of links 708 drives the
fingers 604 of pusher 600 out through apertures 548 of anvil hub
514, through apertures 105 in the cap 104 of loading unit 100, and
against the annular flange 174 at the proximal end of actuator
170.
[0153] The continued distal movement of pusher 600 drives actuator
170 distally, overcoming the spring force exerted by retaining clip
184 to hold actuator 170 in a fixed axial position relative to
shaft 180. The distal movement of actuator 170 causes the tapered
surface 178 on each of the fingers 176 of the actuator to engage
the cam surface 146 of a corresponding staple pusher 130. As a
result of the interaction of tapered surfaces 178 with staple
pushers 130, the staple pushers are driven radially outward,
pushing staples 150 ahead of them. Staples 150 move radially
outward until the free ends of the legs 154 and 156 of the staples
contact the staple returns 528 on anvils 518. Staple returns 528
cause staple legs 154 and 156 to turn inwardly and back toward the
crossmember 152 of the staple so as to form a "CB" configuration,
shown in FIG. 31, when the stapling operation has been completed.
Staples 150 are deployed so that one leg 156 of each staple pierces
graft 10 and aorta A and is then turned back through the aorta. The
other leg 154 of each staple pierces aorta A directly and is then
turned back through the aorta, forming a loop around the free edge
of graft 10 to hold it tightly to the aorta. The tips of the staple
legs may or may not pierce graft 10 from the opposite side.
[0154] As the fingers 176 of actuator 170 progress distally, the
tips of the fingers will engage the proximal surface of cam ring
208, driving the cam ring and retainer 190 connected thereto toward
cap 106, as shown in FIG. 29. This movement will push the tips 198
of the fingers 192 of retainer 190 off of the cuff 18 of graft 10.
At the same time, cam ring 208 will be moved distally relative to
the cams 230 on the fingers 222 of retainer 220 until cam surface
230a is riding on the outer periphery of the cam ring. Continued
distal movement of cam ring 208 will cause fingers 222 to move
inwardly of loading unit 100 as a result of the inward biasing
force exerted by the fingers, thereby releasing the tips 228 of the
fingers from graft 10. Hence, the actuation of trigger mechanism
270 to deploy staples 150 simultaneously releases retainers 190 and
220 from the cuff 18 of the graft.
[0155] Following the deployment of staples 150, trigger 672 may be
released, whereupon the biasing force of spring 698 will cause the
trigger to return to its rest position. At the same time, the apex
698 of linkage assembly 680 will move away from handle 512, with
the end 692 of the linkage assembly moving in the proximal
direction. This proximal movement will cause coupling element 694,
tube 702, coupling link 704 and links 708 to also move proximally,
resulting in the withdrawal of the fingers 604 of pusher 600 from
loading unit 100. Anvil assembly 510 may then be placed in the open
condition by rotating knob 610 in the opposite direction, and
instrument 500, with loading unit 100 connected thereto, may be
removed from graft 10, leaving the graft attached to the aorta by a
circumferential line of staples 999, as can be seen in FIG. 38.
Subsequently, the legs 14 and 16 of graft 10 may be sutured in a
conventional fashion to the patient's iliac arteries. The procedure
is completed by removing surgical loop 400 and closing side port 20
of graft 10 through the use of suture 22 to form a purse string
tie, through a conventional suturing operation, or by a surgical
stapling technique, and, where appropriate, by removing any excess
portion of side port 20 from the graft.
[0156] The various components of the present invention may be used
in a conventional open body surgical procedure. The instruments may
also be used to perform a stapling operation laparascopically by
providing the instruments with appropriate seals to prevent the
escape of air used to expand the body cavity during a laparoscopic
procedure.
[0157] In addition to the several embodiments described above, the
various components of the stapling system of the present invention
may be varied in many ways. For example, it will be appreciated
that, where appropriate, any of the features described in
connection with a particular embodiment hereof may be incorporated
in any other embodiment described herein.
[0158] Although the invention herein has been described with
reference to particular embodiments, it is to be understood that
these embodiments are merely illustrative of the principles and
applications of the present invention. It is therefore to be
understood that numerous modifications may be made to the
illustrative embodiments and that other arrangements may be devised
without departing from the spirit and scope of the present
invention as defined by the appended claims.
* * * * *