U.S. patent application number 11/982474 was filed with the patent office on 2008-03-13 for tissue stabilizer having an articulating lift element.
Invention is credited to Harry Leonard II Green, George A. Keller, Mark Steven Ortiz, Paul A. Spence, Warren P. IV Williamson.
Application Number | 20080064919 11/982474 |
Document ID | / |
Family ID | 23575747 |
Filed Date | 2008-03-13 |
United States Patent
Application |
20080064919 |
Kind Code |
A1 |
Williamson; Warren P. IV ;
et al. |
March 13, 2008 |
Tissue stabilizer having an articulating lift element
Abstract
Devices and methods are disclosed for stabilizing tissue within
a patient's body during a surgical operation to provide a
relatively motionless surgical field, such as during a coronary
artery bypass graft procedure. The devices include tissue
stabilizers which engage and provide stabilization to a targeted
area of tissue and further have the ability to engage and
manipulate some portion of tissue within or adjacent the targeted
area to improve the surgical presentation of that portion of
tissue. The tissue stabilizer typically has one or more stabilizer
feet which have a first foot portion configured to provide
stabilization to the targeted tissue and a second foot portion
moveable relative to the first foot portion for manipulating a
portion of tissue to improve the surgical presentation.
Inventors: |
Williamson; Warren P. IV;
(Loveland, OH) ; Spence; Paul A.; (Louisville,
KY) ; Ortiz; Mark Steven; (Milford, OH) ;
Keller; George A.; (Grandview Heights, OH) ; Green;
Harry Leonard II; (Santa Cruz, CA) |
Correspondence
Address: |
LAW OFFICE OF ALAN W. CANNON
942 MESA OAK COURT
SUNNYVALE
CA
94086
US
|
Family ID: |
23575747 |
Appl. No.: |
11/982474 |
Filed: |
November 2, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10137643 |
Apr 30, 2002 |
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11982474 |
Nov 2, 2007 |
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09398535 |
Sep 16, 1999 |
6406424 |
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10137643 |
Apr 30, 2002 |
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Current U.S.
Class: |
600/37 |
Current CPC
Class: |
A61B 2017/0243 20130101;
A61B 2017/306 20130101; A61B 17/02 20130101; A61B 1/32
20130101 |
Class at
Publication: |
600/037 |
International
Class: |
A61B 17/00 20060101
A61B017/00 |
Claims
1. A device for stabilizing tissue within a patient's body for
performing a surgical procedure on said tissue comprising: at least
one stabilizer foot having a first portion and a second portion
coupled to said first portion, said first portion being
substantially rigid and having a tissue engaging surface adapted to
engage a first area on the surface of said tissue; and said second
portion having a vacuum chamber with at least one opening adapted
to engage a second area on the surface of said tissue, said second
portion being moveable relative to said first portion whereby
movement of said second portion relative to said first portion
manipulates the second area of tissue relative to said first area
of tissue.
2. The device of claim 1 wherein said second portion moves upwardly
relative to said first portion.
3. The device of claim 1 wherein said first portion has a vacuum
chamber and said tissue engaging surface has at least one opening
in fluid communication with said vacuum chamber.
4. The device of claim 2 further comprising a raised seal disposed
around the perimeter of said tissue engaging surface.
5. The device of claim 4 wherein said raised seal is
compressible.
6. The device of claim 1 wherein said tissue engaging surface
comprises a textured surface adapted to frictionally engage said
first area on the surface of said tissue.
7. The device of claim 1 further comprising a tension member having
a proximal end and a distal end, said distal end of said tension
member connected to said second portion.
8. The device of claim 7 wherein said proximal end of said tension
member is connected to a tensioning mechanism.
9. The device of claim 8 wherein said tensioning mechanism
comprises a channel adapted to receive said tension member and a
locking member positioned at an angle relative to said channel and
having a free end biased against the interior of said channel.
10. The device of claim 8 wherein said tensioning mechanism
comprises a pivoting member having a pivot axis and said proximal
end of said tension member is attached to said pivoting member at a
predetermined distance from said pivot axis.
11. The device of claim 8 wherein said tensioning mechanism
comprised a spool having an outer surface, said proximal end of
said tension member being operably connected to said outer
surface.
12. The device of claim 7 wherein said tension member is a thread
material.
13. The device of claim 7 wherein said tension member is a flexible
wire.
14. The device of claim 7 wherein said tension member is a
cable.
15. The device of claim 1 wherein said second portion is made of a
flexible material.
16. The device of claim 15 wherein said flexible material is an
elastomer.
17. The device of claim 15 wherein said flexible material is
selected from the group consisting of silicone, urethane rubber,
nitrile rubber, hytrel, and kraton.
18. The device of claim 1 wherein said device comprises a first
stabilizer foot and a second stabilizer foot substantially parallel
to said first stabilizer foot, each of said first stabilizer foot
and said second stabilizer foot having a first portion and a second
portion coupled to said first portion, said first portion being
substantially rigid and having a tissue engaging surface adapted to
engage a first area on the surface of said tissue; and said second
portion having a vacuum chamber with at least one opening adapted
to engage a second area on the surface of said tissue, said second
portion being moveable relative to said first portion whereby
movement of said second portion relative to said first portion
manipulates the second area of tissue relative to said first area
of tissue.
19. A device for stabilizing tissue within a patient's body
comprising at least one stabilizer foot having a first foot portion
adapted to engage a first portion of tissue and a second foot
portion having a vacuum space having at least one opening adapted
to engage a second portion of tissue immediately adjacent said
first portion of tissue, said second foot portion being flexibly
coupled to said first foot portion.
20. The device of claim 19 further comprising a tension member
having a proximal end and a distal end, said distal end being
operably connected to said second foot portion, whereby pulling on
said proximal end causes said second foot portion to move relative
to said first foot portion.
21. The device of claim 19 wherein said first foot portion has a
vacuum chamber having at least one opening adapted to engage said
first portion of tissue.
22. The device of claim 19 wherein said first foot portion has a
textured surface adapted to frictionally engage said first portion
of tissue.
23. The device of claim 19 wherein said second foot portion defines
a vacuum space having a perimeter edge adapted to seal against said
second portion of tissue.
24. The device of claim 19 wherein said second foot portion
comprises an elastomeric material.
25. A device for stabilizing tissue within a patient's body for
performing a surgical procedure on said tissue comprising: a base
member having an interior chamber and a substantially cylindrical
bore, said bore having a first end in fluid communication with said
interior chamber and a second end open to the exterior of said base
member; a stabilizer foot having a substantially cylindrical
fitting having a longitudinal axis, at least a portion of said
fitting positioned within said bore and being rotatable within said
bore about said longitudinal axis; and said stabilizer foot having
a first foot portion adapted to engage a first portion of tissue
and a second foot portion adapted to engage a second portion of
tissue adjacent said first portion of tissue, said second foot
portion being flexibly coupled to said first foot portion.
26. The device of claim 25 further comprising a tension member
having a proximal end and a distal end, said distal and being
operably connected to said second foot portion, whereby pulling on
said proximal end causes said first second foot portion to move
relative to said first foot portion.
27. The device of claim 25 wherein said second foot portion
comprises an elastomer.
28. The device of claim 25 wherein said second foot portion defines
a vacuum space having at least one opening in fluid communication
with said second portion of tissue.
29. The device of claim 28 wherein said vacuum space has a
perimeter edge adapted to seal against said second portion of
tissue.
30. A device for stabilizing tissue within a patient's body for
performing a surgical procedure on said tissue comprising: a base
member having a shaft mounted for rotation relative to said base
member, said shaft having a longitudinal axis and at least one
threaded portion; a first stabilizer foot having a first tissue
engaging surface and a second stabilizer foot having a second
tissue engaging surface, said first and second tissue engaging
surfaces extending generally perpendicular to said longitudinal
axis, at least one of said stabilizer feet being operably
associated with said threaded portion of said shaft such that
rotation of said shaft causes said at least one of said stabilizer
feet to move relative to the other.
31. The device of claim 30 wherein said shaft has a first threaded
portion and a second threaded portion and said first stabilizer
foot is adapted to receive and traverse along said first threaded
portion and said second stabilizer foot is adapted to receive and
traverse along said second threaded portion.
32. The device of claim 31 wherein said second threaded portion has
threads which are opposite-handed to that of the threads of said
first portion.
33. The device of claim 30 wherein at least one of said first and
second stabilizer feet further comprise a flexible member coupled
thereto, said flexible member having a vacuum chamber having at
least one opening for engaging a portion of tissue with negative
pressure.
34. The device of claim 33 wherein said flexible member comprises
an elastomer.
35. A method of stabilizing a coronary artery on a beating heart
for performing a surgical procedure on the coronary artery
comprising the steps of: providing a tissue stabilizer having at
least one stabilizer foot having a first portion adapted to engage
a first area on the surface of the heart adjacent said coronary
artery and a second portion adapted to engage a second area on the
surface of the heart, said second portion being coupled to said
first portion and moveable relative to said first portion; engaging
said first area with said first portion to substantially stabilize
at least a portion of the heart; engaging said second area with
said second portion; moving said second portion relative to said
first portion whereby said second area of said heart is moved
relative to said first area of said heart.
36. The method of claim 35 wherein said second area includes at
least a portion of said coronary artery.
37. The method of claim 34 wherein further including the step of
creating an arteriotomy having a first side and a second side in
said coronary artery after engaging said first area with said first
portion.
38. The method of claim 37 wherein said second area includes a
portion of said coronary artery adjacent said first side of said
arteriotomy whereby the step of moving said second portion relative
to said first portion moves said first side of said arteriotomy
relative to said second side of said arteriotomy.
39. The method of claim 38 further comprising the step of placing
at least one suture through a said first side of said arteriotomy.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to surgical
instruments, and more particularly to devices and methods for
stabilizing and manipulating tissue during surgery. The tissue
stabilizers described herein are particularly useful for
stabilizing the beating heart during coronary artery bypass graft
surgery. The field of the invention is cardiac tissue stabilizers
having specially designed moveable portions.
BACKGROUND OF THE INVENTION
[0002] Certain surgical procedures require the surgeon to perform
delicate operations on tissues within the body that are moving or
otherwise unstable. For example, a large and growing number of
surgeons are routinely performing successful coronary artery bypass
graft surgery on the beating heart. In a typical coronary artery
bypass graft (CABG) procedure, a blocked or restricted section of
coronary artery, which normally supplies blood to a portion of the
heart, is bypassed using a source vessel or a graft vessel to
re-establish blood flow to the artery downstream of the blockage.
This procedure requires the surgeon to create a fluid connection,
or anastomosis, between the source or graft vessel and an
arteriotomy or incision in the coronary artery. Forming in
anastomosis between two vessels in this manner is a particularly
delicate procedure requiring the precise placement of tiny sutures
in the tissue surrounding the in the coronary artery and in the
source or graft vessel so that the two may be sutured together.
[0003] To ensure that the sutures may be placed with the required
accuracy and precision to yield an anastomosis having long term
patency, a number of devices have been developed to stabilize a
portion of the heart in the vicinity of the target coronary artery.
The vast majority of devices suitable for successfully stabilizing
the beating heart use either compression or vacuum, or both, to
engage and immobilize a portion of cardiac tissue, preferably along
opposite sides of the target artery. Devices configured to use a
compressive force to stabilize a surgical site on the beating heart
can be found, for example, in U.S. Pat. No. 5,894,843 to Benetti et
al. Examples of devices configured to use negative pressure or
vacuum to stabilize or to assist in stabilizing cardiac tissue are
described, for example, in U.S. Pat. No. 5,727,569 to Benetti et
al. and U.S. Pat. No. 5,836,311 to Borst et al.
[0004] Although some stabilization devices reduce or eliminate the
motion of the heart at the surgical site or target artery,
visualization or presentation of the target artery, and more
specifically the arteriotomy to which a vessel will be anastomosed,
could be improved in certain surgeries. While a properly stabilized
vessel will usually exhibit acceptable visualization, some
operations and tissue geometries can distort the tissue surrounding
the coronary artery or the coronary artery itself in a manner which
(complicates the completion of the anastomosis. For instance,
excessive pushing on the cardiac tissue along each side of the
coronary artery may tend to flatten the target artery top to bottom
while pulling may tend to compress the target artery side to side
as tissue is pulled higher than the target artery. In other
instances, the target coronary artery is not conveniently located
along the surface of the myocardium, but instead is partly or
completely covered by fat or other tissue. In such cases, the
stabilization forces alone can do little to optimize the
visualization and presentation of the target artery.
[0005] The presentation of the target vessel and the arteriotomy is
a significant factor in eliminating anastomotic errors which may
cause vessel damage or a less than optimal anastomosis which may
lead to failure of the anastomosis. When the arteriotomy is not
optimally presented, there is a higher likelihood of incurring a
surgical error in the formation of the anastomosis. To suture an
anastomosis the surgeon generally works his needle from the inside
vessel wall to the outside of the vessel wall. If the vessel is
flattened, for example, it becomes more likely for the surgeon to
accidentally catch the back wall of the vessel with the curved
suture needle as the suture is placed in the tissue surrounding the
arteriotomy. When the vessel is compressed side to side, it becomes
more difficult to catch only the desired side of the arteriotomy
without also catching the other side.
[0006] When the edges of the arteriotomy are not presented as
desired, the surgeon may be required to manually manipulate the
target artery using forceps or the like. The surgeon must be
careful to only manipulate the vessel at the outside edges of the
incision as manipulation to the interior of the vessel wall may
cause damage to the soft intimal layer of the vessel leading to
scarring and often late restenosis. Most often, the surgeon will
try to only manipulate the tunica adventitia or outer coat of the
vessel using forceps or other suitable instrument to present the
arteriotomy in a manner which allows an accurate placement of each
suture in the vessel from the inside out.
[0007] Even in the best of circumstances this manual manipulation
of the vessel to facilitate each suture placement is tedious, time
consuming, and increases the likelihood of vessel damage. This
problem will become even more magnified as surgeons move to manual,
computer-assisted, and robotic endoscopic procedures in which the
surgeons will be attempting to complete anastomotic procedures in
remote and difficult places. Delicate manipulation of the vessel
walls while suturing becomes increasingly difficult as the surgeon
becomes further removed from the surgical site by longer
instruments, the size of the surgical site decreases leaving
inadequate space to accommodate multiple instruments, and the
access incisions become smaller thus limiting instrument
maneuverability.
[0008] In view of the foregoing, it would be desirable to have
methods and devices which provide stabilization of the surgical
site and target coronary artery and also provide favorable
presentation of the edges of the arteriotomy so that manual
manipulation of the vessel itself is reduced or eliminated. It
would further be desirable to have stabilization and presentation
devices which are adaptable to anatomical variations to aid in
exposure of intramyocardial vessels and provide optimal vessel
presentation over a wide range of operating conditions.
[0009] SUMMARY OF THE INVENTION
[0010] The present invention will be described for use during CABG
surgery, but the invention is not limited thereto, and is
contemplated to be useful for other surgical procedures as
well.
[0011] The present invention involves a tissue stabilizer having
one or more stabilizer feet which are adapted to engage the heart
tissue adjacent a target artery desired to be stabilized. In
preferred embodiments of the present invention, the tissue
stabilizer feet typically have a first foot portion which provides
stabilization and a moveable portion which primarily facilitates
the manipulation of the target coronary artery or local tissue
surrounding the target coronary artery.
[0012] One aspect of the present invention involves a tissue
stabilizer having at least one stabilizer foot having a first
portion and a second portion coupled to the first portion. The
first portion is preferably substantially rigid having a tissue
engaging surface adapted to engage a first area on the surface of
the tissue to be stabilized. The second portion may have a vacuum
chamber with at least one opening adapted to engage a second area
on the surface of the tissue. Preferably, the second portion is
moveable relative to the first portion whereby movement of the
second portion relative to the first portion manipulates the second
area of tissue relative to the first area of tissue. In a preferred
embodiment, the second portion, or at least a portion of the second
portion, flexes, pivots, or otherwise moves upwardly relative to
the first portion.
[0013] By way of example only, the tissue engaging surface may
comprise a textured surface adapted to frictionally engage the
first area on the surface of the tissue or may include a vacuum
chamber and at least one opening in fluid communication with the
vacuum chamber. When the tissue engaging surface involves a vacuum
chamber, a raised seal may be disposed completely around the
perimeter of the tissue engaging surface. Preferably, the raised
seal is compressible so that it may conform somewhat to the surface
of the tissue, but may be relatively rigid to more aggressively
contact the tissue surface to form a seal.
[0014] The device my include a tension member having a distal end
connected to the second foot portion. The tension member may be
pulled or otherwise operated to cause the desired movement of the
second portion. The tension member may be a thread material, a
flexible wire, a cable, a braid, or other linkage by which the
second portion can be manipulated.
[0015] The proximal end of the tension member may be connected to a
tensioning mechanism. In one variation, the tensioning mechanism
may include a channel adapted to receive the tension member and a
locking member positioned at an angle relative to the channel and
having a free end biased against the interior of said channel to
trap and secure a portion of the tension member between the channel
and the free end. In another variation, the tensioning mechanism
may comprise a pivoting member having a pivot axis. The proximal
end of the tension member may be attached to the pivoting member at
a predetermined distance from the pivot axis. The tension member
may also involve a spool having an outer surface about which the
proximal end of the tension member may be operably connected.
[0016] In preferred embodiment, the second portion is made of a
flexible material. Suitable material for the second portion may
include silicone, urethane rubber, nitrile rubber, hytrel, kraton,
or other medical grade flexible materials. Most preferably, the
second portion comprises an elastomer.
[0017] In one preferred embodiment, the tissue stabilizer has a
first stabilizer foot and a second stabilizer foot substantially
parallel to the first stabilizer foot, each of the first and second
stabilizer feet having a first portion and a second portion coupled
to the first portion. The first portion is preferably substantially
rigid and has a tissue engaging surface adapted to engage a first
area on the surface of the tissue. The second portion preferably
has a vacuum chamber with at least one opening adapted to engage a
second area on the surface of the tissue and is moveable relative
to the first portion whereby movement of the second portion
relative to the first portion manipulates the second area of tissue
relative to the first area of tissue. Preferably, the second
portion is adapted to lift or roll up the second area of tissue
relative to the first area of tissue stabilized by the first foot
portions of the stabilizer feet.
[0018] Another aspect of the present invention involves a device
for stabilizing tissue within a patient's body comprising at least
one stabilizer foot having a first foot portion adapted to engage a
first portion of tissue and a second foot portion having a vacuum
space having at least one opening adapted to engage a second
portion of tissue immediately adjacent the first portion of tissue,
the second foot portion being flexibly coupled to the first foot
portion. The tissue stabilizer may further include a tension member
having its distal end operably attached to the second foot portion
whereby pulling on the proximal end of the tension member causes
the second foot portion to move relative to the first foot
portion.
[0019] To engage the first portion of tissue, the first foot
portion preferably has a vacuum chamber having at least one opening
adapted to engage the first portion of tissue with negative
pressure or a textured surface adapted to frictionally engage the
portion of tissue. The textured surface may include a large number
of small protrusions which are preferably formed by chemical
machining or etching or other suitable process. To engage the
second portion of tissue, the second foot portion preferably
defines a vacuum space having a perimeter edge adapted to seal
against the second portion tissue. Preferably, the second foot
portion comprises an elastomeric material.
[0020] Another aspect of the present invention involves a device
for stabilizing tissue within a patient's body for performing a
surgical procedure on the tissue comprising a base member having an
interior chamber and a substantially cylindrical bore and a
stabilizer foot having a mating fitting positioned within said bore
and being rotatable within said bore. The bore preferably has a
first end in fluid communication with the interior chamber and a
second end open to the exterior of the base member. The fitting is
preferably substantially cylindrical having a longitudinal axis
about which the fitting rotates within the bore. The stabilizer
foot may have a first foot portion adapted to engage a first
portion of tissue and a second foot portion adapted to engage a
second portion of tissue adjacent the first portion of tissue, the
second foot portion being flexibly coupled to the first foot
portion.
[0021] The second portion is preferably made of an elastomer and
defines a vacuum space or chamber having at least one opening in
fluid communication with the second portion of tissue. Preferably,
the vacuum space has a perimeter edge adapted to seal against the
second portion of tissue.
[0022] Another aspect of the present invention involves a device
for stabilizing tissue within a patient's body for performing a
surgical procedure on the tissue comprising a first stabilizer foot
having a first tissue engaging surface, a second stabilizer foot
having a second tissue engaging surface, and base member having a
shaft mounted for rotation relative to the base member. The shaft
preferably has at least one threaded portion. The first and second
tissue engaging surfaces may extend generally perpendicular to the
longitudinal axis of the shaft. At least one of the stabilizer feet
may be operably associated with the threaded portion of the shaft
such that rotation of the shaft causes one of the stabilizer feet
to move relative to the other.
[0023] In a preferred embodiment, the shaft has a first threaded
portion and a second threaded portion and the first stabilizer foot
is adapted to receive and traverse along the first threaded portion
and the second stabilizer foot is adapted to receive and traverse
along the second threaded portion. Preferably, the second threaded
portion has threads which are opposite-handed to that of the
threads of the first portion. With that configuration, rotation of
the shaft in a first direction moves the stabilizer feet closer
together while rotation in the opposite direction moves the feet
further apart.
[0024] One or both of the stabilizer feet may further include a
flexible member moveably coupled thereto, the flexible member
having a vacuum chamber having at least one opening for engaging a
portion of tissue with negative pressure. In a preferred
embodiment, the flexible member comprises an elastomer.
[0025] Another aspect of the present invention involves a method of
stabilizing a coronary artery on a beating heart for performing a
surgical procedure on the coronary artery. The method preferably
involves the steps of providing a tissue stabilizer having at least
one stabilizer foot having a first portion adapted to engage a
first area on the surface of the heart adjacent the coronary artery
a second portion adapted to engage a second area on the surface of
the heart, engaging the first area with the first portion to
substantially stabilize at least a portion of the heart, engaging
the second area with the second portion, and moving the second
portion relative to the first portion whereby the second area of
the heart is moved relative to the first area of the heart.
Preferably, the second area includes at least a portion of the
coronary artery.
[0026] The method may also include the step of forming an incision
or having a first side and a second side in the coronary artery
after engaging the first area with the first portion. The second
area preferably includes a portion of the coronary artery adjacent
to the first side of the arteriotomy whereby the step of moving the
second portion relative to the first portion moves the first side
of the arteriotomy relative to the second side of the arteriotomy.
Once the desired side of the arteriotomy has been positioned or
oriented as desired, one or more sutures may be placed through the
arteriotomy or the tissue immediately adjacent the incision.
[0027] In a preferred embodiment, the tissue stabilizer has first
and second stabilizer feet, each having a first portion and a
second portion coupled to said first portion and moveable relative
to said first portion. The method preferably includes the step of
adjusting one or both of the stabilizer feet relative to each other
to ensure a good fit against the surface of the heart. The first
portion of each stabilizer foot may then be engaged with the
surface of the heart on opposite sides of the coronary artery. An
arteriotomy having a first side and a second side may be created in
the coronary artery. In the preferred method, the first side is
positioned relative to the second side by engaging one or both of
the second portions of the stabilizer feet with the heart and
moving one or both relative to the first portions. The method may
also include the step of manipulating the first and second
stabilizer feet relative to one another to improve presentation of
the arteriotomy.
[0028] These and other features of the present invention will
become more fully apparent from the following description and
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a perspective view illustrating a tissue
stabilizer constructed according to the principles of the present
invention.
[0030] FIG. 2 is a cross-sectional view taken generally along line
2-2 of FIG. 1 illustrating the unactuated tissue stabilizer over a
target vessel.
[0031] FIG. 3 is a cross-sectional view taken generally along line
2-2 of FIG. 1 illustrating the tissue stabilizer over a target
vessel, but the position is altered to show the stabilizer in an
actuated position.
[0032] FIG. 4 is a perspective view illustrating another tissue
stabilizer according to the principles of the present
invention.
[0033] FIG. 5 is a perspective view of an alternative embodiment of
the tissue stabilizer of the present invention
[0034] FIG. 6 is a partial perspective view of a stabilizer foot
illustrating an alternative articulating member.
[0035] FIGS. 7 and 8 are front and rear perspective views of a
tissue stabilizer according to the principles of the present
invention.
[0036] FIG. 9 is a cross-sectional view taken along line 9-9 as
shown in FIG. 7.
[0037] FIG. 10 is a top plan view illustrating another embodiment
of the tissue stabilizer of the present invention.
[0038] FIG. 11 is a cross-sectional view taken along line 11-11 as
shown in FIG. 10.
[0039] FIG. 12 is a bottom perspective view of the tissue
stabilizer of FIG. 10.
[0040] FIG. 13 is a cross-sectional view of the stabilizer foot
taken along line 13-13 as shown in FIG. 10.
[0041] FIG. 14 is a cross-sectional view illustrating a variation
of the stabilizer foot of FIG. 10.
[0042] FIG. 15 is a perspective view of a preferred suture
stay.
[0043] FIG. 16 is a partial top view of an alternative articulating
mechanism.
DETAILED DESCRIPTION
[0044] The present invention involves devices and methods for
stabilizing tissue during a surgical operation. The devices
described herein may be used in a wide variety of surgical
applications that require a tissue structure to be stabilized or
immobilized to provide a substantially stable and motionless
surgical field on which a surgical procedure can be performed. By
way of example only, the preferred embodiments described in detail
below are directed to the stabilization of a portion of the heart
to facilitate a surgical procedure on or within the heart, such as
a coronary artery bypass graft (CABG) procedure.
[0045] Although the devices and methods of the present invention
may be applied to conventional stopped-heart and beating heart
procedures, they are preferably used to stabilize the beating heart
during a CABG operation which has been specially developed to
facilitate completion of an anastomosis, typically between a target
coronary artery and a bypass graft or source artery, without
requiring cardiac arrest and without cardiopulmonary bypass.
[0046] A typical beating heart CABG procedure involves accessing
the beating heart by way of a sternotomy, mini-sternotomy,
thoracotomy, mini-thoracotomy, or other suitable access incision,
positioning a tissue stabilizer on, around, or adjacent a coronary
artery to stabilize the coronary artery, creating an arteriotomy in
the coronary artery, and forming an anastomosis between the bypass
graft or source artery and the arteriotomy. Typically, the tissue
stabilizer has a heart engaging member at one end for engaging the
surface of the beating heart and is connected at the other end to a
stationary object such as a sternal retractor, rib retractor, or
other such stationary structure. Exemplar devices and methods for
accessing the beating heart and mounting a stabilizer device are
disclosed in co-pending U.S. patent application Ser. No. 09/305,810
titled "A SURGICAL RETRACTOR APPARATUS FOR OPERATING ON THE HEART
THROUGH AN INCISION", the entirety of which is herein incorporated
by reference.
[0047] The tissue stabilizers of the present invention generally
have one or more stabilizer feet which are adapted to contact the
heart tissue adjacent the target artery desired to be stabilized.
In preferred embodiments of the present invention, the tissue
stabilizer feet typically have a relatively rigid portion which
provides the bulk of the tissue stabilization and a moveable or
flexible portion which facilitates the fine manipulation of the
target coronary artery or the local tissue surrounding the target
coronary artery.
[0048] The rigid portion is sufficiently rigid to facilitate
effective immobilization of at least a portion of the cardiac
tissue surrounding a target artery to be stabilized, generally
using a compressive force, negative pressure, or both. Preferably,
the moveable or flexible portion is adapted to engage a portion of
a target artery in the vicinity of an arteriotomy and may be
activated to manipulate the engaged portion to obtain an optimum
presentation of the edges of an arteriotomy for the purpose of
completing a successful anastomosis. Generally, the moveable or
flexible portion operates to lift, and more preferably to lift and
retract the engaged portion of tissue. In a preferred
configuration, the stabilizer foot has a moveable or flexible
portion which can be articulated relative to the relatively rigid
portion.
[0049] Referring to the figures wherein like numerals indicate like
elements, a preferred tissue stabilizer is illustrated in FIGS.
1-3. Tissue stabilizer 100 preferably has first and second
stabilizer feet 105 and 106 which are typically oriented and spaced
apart an appropriated distance to engage the surface of the heart
on opposite sides of a target coronary artery in an adult human
patient. Tissue stabilizer 100 is typically positioned such that
the coronary artery runs lengthwise in the space between stabilizer
feet 105 and 106.
[0050] For beating heart procedures where it is often, although not
universally, undesirable to occlude the target vessel, tissue
stabilizer 100 preferably has a construction that does not occlude
of otherwise compress the target coronary artery as stabilizer feet
105 and 106 are placed on opposite sides of the vessel to be
stabilized. When stabilizer feet 105 and 106 are connected to a
common support member or base, the base may include a recessed or
raised portion to ensure that the vessel does not become occluded
by stabilizer feet 105 and 106. For example, base 115, which
generally spans over a portion of the target coronary artery to
structurally connect stabilizer feet 105 and 106, preferably has a
raised portion or bridge 140 under which the coronary vessel may
pass without being significantly compressed or occluded when
stabilizer feet 105 and 106 are engaged to stabilize the heart in
the vicinity of the target vessel.
[0051] Stabilizer feet 105 and 106 are connected to base 115 which
typically has mounting or connecting features for operably
attaching a suitable stabilizer shaft or other such structure which
in turn may be mounted to a stable platform such as a retractor.
The construction of the shaft and attachment to base 115 may be any
suitable configuration which allows the desired maneuverability of
the tissue stabilizer relative to the shaft. Tissue stabilizer 100
preferably has shaft 125 connected to base 115 at distal connection
131.
[0052] Shaft 125 may have a number of functions and features.
Preferably, shaft 125 includes vacuum lumen 126 for supplying a
negative pressure to a chamber or manifold (not shown) within base
115, and ultimately to stabilizer feet 105 and 106. In one
embodiment, shaft 125 is made of a flexible material having a
support rod 130. Support rod 130 is preferably of sufficient
rigidity to impart the required stabilization forces to stabilizer
feet 105 and 106. In one embodiment, at least a portion of support
rod 130 may be malleable to allow the device to be oriented and
positioned as desired.
[0053] In a preferred embodiment, stabilizer feet 105 and 106 have
fixed or substantially rigid portions 110 and 112 and moveable
portions 111 and 113, respectively. Rigid portion 110 and 112
extend from base 115 and are adapted to engage the surface of heart
145 adjacent the target artery (See FIGS. 2-3). In this embodiment,
rigid portions 110 and 112 have tissue engaging or contacting
surfaces 114 which are preferably roughened or textured to ensure
that the device does not slip relative to the surface of the heart
when tissue contacting surfaces 114 are pressed against the heart.
Tissue contacting surfaces 114 are preferably textured using a
chemical machining or like process.
[0054] Moveable portions 111 and 113 are preferably positioned
inside of rigid portions 110 and 112. The interior edges of
moveable portions 111 and 113 are separated by a small distance 135
which may range from essentially zero to a distance which is
slightly larger than the target vessel to be stabilized. Moveable
portions 111 and 113 are preferably positioned to engage the tissue
immediately surrounding the target vessel, and if desired, a
portion of the target vessel wall itself so that the arteriotomy
may be presented for suturing by articulating moveable portions 111
and 113. referring to FIG. 1, distance 135 is preferably less than
about 0.2 inches, more preferably less than about 0.125 inches.
[0055] Preferably, moveable portions 111 and 113 may be articulated
relative to rigid portions 110 and 112. As will be discussed in
detail below with reference to FIG. 6, moveable portions 111 and
113 may be a rigid member which articulates relative to the rigid
foot portions, for example, by way of a pivot, hinge, linkage, or
other mechanism. However, simple mechanisms and single axis pivots
do not generally provide a motion of the moveable portion which
matches the natural shape and curvature of the edges of the fixed
length incision of a standard arteriotomy as it is urged open for
suturing. The edges of an incision creating an arteriotomy somewhat
resembles a shape like two open eyelids. As this shape is difficult
to produce with single axis rotation, moveable portions 111 and 113
are preferably thin elastically deformable members. In preferred
embodiment, moveable portions 111 and 113 may be made from a
medical grade elastomer or other flexible material such as, for
example, silicone, urethane rubber, nitrile rubber, hytrel, kraton,
or other medical grade material.
[0056] In a preferred embodiment, moveable portions 111 and 113 are
elastic members having a tension member attached thereto,
preferably at the center of moveable portions 111 and 113. By
pulling back on the elastic members using a generally central
tension member, the elastic material creates a compound curve which
mimics the natural shape of the arteriotomy as it is pulled open.
Thus, when moveable portions 111 and 113 are provided with a means
for engaging the exterior of target artery 150, it is able to pull
open arteriotomy 151 with a compound shape that does not harm or
stress the target artery or the arteriotomy. Preferably, the
compound deflected shape of moveably portions 111 and 113 tend to
lift, and more preferably lift and retract, the edges of the
arteriotomy.
[0057] The means for engaging the exterior of the target artery, or
other surrounding tissue, may include suitably positioned vacuum
chambers, suction ports, sutures or the like fixing the moveable
portions 111 and 113 to the tissue structure to be moved, adhesive
tapes or substrates, or any other suitable instrumentality for
engaging the desired tissue structure so that it may be lifted or
otherwise manipulated as moveable portions 111 and 113 are
articulated. In a preferred embodiment, moveable portions 111 and
113 have vacuum chambers 146 and 147, respectively, positioned and
adapted to engage the exterior of the target artery or other
surrounding tissue. In a preferred embodiment, vacuum is supplied
to vacuum chambers 146 and 147 through vacuum tubes 136 and 138
which are fluidly connected to base 115 which is in fluid
communication with vacuum lumen 126 of shaft 125.
[0058] Moveable portions 111 and 113 may have base extension 148
adapted to contact the heart forming part of the perimeter seal
around vacuum chambers 146 and 147. The length of base extension
148, at least in part, determines the width of the vacuum opening
which will engage tissue. A base extension having a longer length
tends to limit the tissue engaged by the negative pressure within
vacuum chambers 146 and 147 to potentially only the exterior
surface of target artery 150. If it is desired to also capture a
greater amount of the tissue surrounding target artery 150, then
base extension 148 can be shortened or eliminated. In an optional
embodiment, base extension 148 may extend completely across vacuum
chambers 1476 and 147 to form an integral bottom of a completely
enclosed sealed chamber. The integral bottom may have one or more
holes or openings appropriately placed to engage the desired
portion of the target artery or surrounding tissue with the
negative pressure supplied within the chamber.
[0059] Articulation of moveable portions 111 and 113 is preferably
accomplished by pulling using a tension member or other such
linkage. Preferably, the tension member is in the form of a
flexible wire, cable, braid, or suture thread, such as pull wires
132 and 134. Pull wires 132 and 134 may be routed proximally on the
device for easy access. Preferably, Pull wire 132 and 134 are
attached to moveable members 111 and 113 at attachment bosses 142
and 144 and routed through guide tubes 120 and 122 and through wire
lumen 127 and 128 provided in support shaft 125. The proximal ends
of pull wires 132 and 134 may be accessed by the surgeon directly
using a suitable instrument or may be attached to any suitable
automated tensioning device, an example of which is discussed below
with reference to FIG. 4.
[0060] To perform the desired suturing around the edges of an
arteriotomy, tissue stabilizer 100 is brought into contact with the
surface of heart 145, with stabilizer feet 105 and 106 positioned
on opposite sides of target vessel 150. A stabilizing force is
delivered to stabilizer feet 105 and 106 by way of shaft 125 and
shaft 125 is typically secured in place to a rigid support such as
a sternal or rib retractor. With a localized portion of the beating
heart stabilized under rigid portions 110 and 112, arteriotomy 151
is created in target vessel 150 as shown in FIG. 2. A negative
pressure is introduced to vacuum lumen 126 which is communicated to
vacuum chambers 146 and 147 within moveable portions 111 and 113
thus causing moveable portions 111 and 113 to become engaged with
target artery 150.
[0061] Next one of the moveable portions, 111 for example, is
articulated as shown in FIG. 3 optimally presenting one edge of the
arteriotomy to allow needle 155 having suture thread 156 to be
accurately placed in the edge of the arteriotomy, typically using a
long forceps 160 or like instrument (or end effector if the
procedure is being performed robotically). After all the suturing
has been completed along the edge of the arteriotomy being
presented by moveable portion 111, pull wire 132 is released. The
opposite side of the arteriotomy may then be presented by
articulating moveable portion 113 using pull wire 134. If desired,
both moveable portions 111 and 113 may be articulated at the same
time to lift up on both sides of the arteriotomy.
[0062] A tissue stabilizer having a tension member actuator is
illustrated in FIG. 4. Tissue stabilizer 200 again has a first and
second stabilizer feet 205 and 206 attached to base 215 to which
shaft 225 is connected at distal connection 231. Stabilizer feet
205 and 206 have fixed or rigid portions 210 and 212 and flexible
or moveable portions 211 and 213, respectively. Moveable portions
211 and 213 preferably have vacuum chambers adapted to engage the
desired tissue structure as described above.
[0063] In the embodiment illustrated in FIG. 4, the vacuum chambers
of moveable portions 211 and 213 are fluidly connected directly to
base member 215 at base connections 240 and 241. In addition, rigid
portions 210 and 212 are relieved somewhat so that the material of
moveable portions 211 and 213 can be extended to form flexible tips
216 and 218. Flexible tips 216 and 218 further protect against any
unwanted compression of target artery 150 at the tip region of the
device as the stabilization forces are supplied through rigid
portions 210 and 212 to the surface of the heart.
[0064] Moveable portions 211 and 213 may be actuated by any
suitable linkage, lever, articulating mechanism or tension member.
Preferably moveable portions 211 and 213 have tension members 232
and 234 attached centrally thereto. Tension members 232 and 234 are
preferably made of suture thread, wire, cable, braid, ribbon or the
like. Tension members 232 and 234 are routed through guide tubes
220 and 222 and into guide lumen 227 and 228 associated with shaft
225. Tension members 232 and 234 may be connected proximally to any
suitable actuator mechanism which allows the user to conveniently
apply an appropriate force to tension members 232 and 234 to cause
moveable portions 211 and 213 to retract as desired to effectuate
an optimum presentation of target vessel 150.
[0065] In a preferred embodiment, the actuator mechanism comprises
one or more rotating elements or spools for winding up tension
members 232 and 234, thereby causing the desired articulation of
moveable members 211 and 213. Preferably, collar 235 is attached to
a structural member or rod 230 which extends through at least a
portion of shaft 225. Axle or pin 239 extends from collar 235,
preferably from opposite sides. Spools 237 and 238 have a mating
bore for receiving and pivotally rotating about pin 239. When
proximal ends of tension members 237 and 238 are connected to or
wrapped around spools 237 and 238 such that rotation of the spools
causes tension members 237 and 238 to wind up, thus pulling on
moveable portions 211 and 213 at their distal attachments. Each
spool may have a knurled knob 236 or the like to facilitate
convenient actuation of the mechanism by the user.
[0066] Another embodiment of a tissue stabilizer constructed
according to the principles of the present invention is illustrated
in FIG. 5. Tissue stabilizer 250 has first and second feet 251 and
252 having rigid portions 253 and 255 and moveable portions 254 and
256 which articulate in response to pulling on tension members 278
and 279. Moveable portions 254 and 256 have vacuum connections 261
and 262 individually associated therewith. Vacuum supply lines 263
and 264 can be directly connected to vacuum connections 261 and 262
to communicate negative pressure to the vacuum chambers of moveable
portions 254 and 256.
[0067] With the vacuum supply lines connected directly to moveable
portions 254 and 256, base member 280 is not required to function
as a manifold to communicate negative pressure from a vacuum lumen
to the stabilizer feet, but need only be a substantially rigid lo
structure to which stabilizer feet 251 and 252 are operably
connected. Further, the shaft used to stabilize and transmit the
required stabilizing forces to the stabilizer feet becomes
unburdened from the requirement of having a vacuum lumen as
described in the previous examples.
[0068] In a preferred embodiment, base 280 has a ball 270 extending
upwardly therefrom to which shaft 265 having a distal housing 272
having a socket for mating with ball 270. Preferably shaft 265 is
substantially rigid and may have a center rod 275 which may be
forced in the direction of arrow 276 to prevent any relative
movement between ball 270 and distal housing 272. This arrangement
allows the orientation of the stabilizer feet to be adjusted as
desired and then locked into place for the application of the
stabilizing forces through shaft 265. Suitable constructions for
ball 270, shaft 265, center rod 275 and mechanisms for causing
enter rod 275 to lock the ball and housing in place can be found,
for example, in co-pending U.S. patent application Ser. No.
08/931,158, titled "SURGICAL INSTRUMENTS AND PROCEDURES FOR
STABILIZING THE BEATING HEART DURING CORONARY ARTERY BYPASS GRAFT
SURGERY" and EPO Serial No. 97102789.1, the entirety of which is
herein incorporated by reference.
[0069] As mentioned above, the moveable portions of the stabilizer
feet of the present invention are preferably made of a flexible
material which elastically deforms to a desirable shape for
presenting the edges of an arteriotomy of a target vessel. It
should be noted however that other materials and configurations are
intended to be within the scope of the present invention. FIG. 6,
for example, illustrates a stabilizer foot variation in which the
moveable portion of the stabilizer foot is connected to the rigid
portion by way of a pivot or hinge. Preferably, stabilizer foot 290
has a fixed foot portion 292 and a pivotally connected articulating
member 291. In a preferred embodiment, articulating member 291 and
fixed foot portion 292 have an alignment of alternating cylinders
293 and 294, respectively, through which a pin or rod 295 may be
inserted to create a hinge.
[0070] Preferably, fixed foot portion 292 is sufficiently rigid to
provide adequate stabilization of the tissue at the surgical site.
Articulating member 291 is adapted to engage the target artery or
immediately surrounding tissue. Once the desired tissue 291 is
engaged, articulating member 291 can be manipulated to lift the
tissue to improve the surgical presentation. A tension member or
other suitable link may be connected to raised boss 296 to
effectuate the desired articulation.
[0071] Articulating member 291 may engage the desired tissue using
in any suitable maimer including tissue adhesives, negative
pressure, sutures, etc. In a preferred embodiment, articulating
member 291 has a sealed, hollow configuration to which a negative
pressure can be communicated. One or more holes or openings 297
adapted to engage the desired tissue structure may be provided in a
suitable location on the bottom of articulating member 291.
[0072] In addition to articulation of the moveable portions of the
stabilizer feet, it may be desirable to have the ability to adjust
the position of one or both of the stabilizer feet to account for
anatomical variations and surgeon preference. In one embodiment,
illustrated with reference to FIGS. 7-9, tissue stabilizer 300 is
provided with stabilizer feet 305 and 306 which may be adjusted
relative to one another to provide the desired spacing between
stabilizer feet 305 and 306.
[0073] Preferably, stabilizer feet 305 and 306 have or are
connected to threaded blocks 336 and 338, respectively. Central
base housing 330 has a pair of flanges 340 between which knob 332
is housed. Knob 332 has right-hand threaded shaft 334 for
cooperating with right-hand threads in block 338 and left-hand
threaded shaft 333 for cooperating with left-hand threads in block
336. With this configuration rotation of knob 332 in one direction
spreads stabilizer feet 305 and 306 apart while an opposite
rotation brings stabilizer feet 305 and 306 closer together. Thus,
the spacing between the stabilizer feet can be adjusted to properly
position the vessel relative to the stabilizer feet, and in
particular relative to the moveable portion. This tends to ensure
that the articulating portion of the stabilizer feet engages and
lifts the desired portion of the target artery and surrounding
tissue.
[0074] Stabilizer feet 305 and 306 illustrate another variation of
stabilizer feet having a flexible articulating portion for lifting
the target artery or surrounding tissue to improve surgical
presentation of the tissue structure to be sutured or otherwise
operated upon. Referring specifically to FIG. 9, this stabilizer
foot variation involves a stabilizer foot having relatively rigid
member 307 and a moveable or flexible member 310, which together
form an enclosed vacuum space or chamber 345 having an opening 346
for engaging a tissue structure when negative pressure is present
in chamber 345. Flexible member 310 preferably includes a perimeter
edge 313 for creating a seal against the tissue structure. Coil
spring 312, or other suitable mesh or screen member, is preferably
positioned within chamber 345 to prevent excessive collapse of
flexible member 310 into rigid member 307.
[0075] Rigid member 307 preferably has a tissue contacting region
308 having a roughened surface which may include a large number of
small projections 309 to provide the necessary traction against the
surface of the beating heart. The roughed surface may be formed by
coining, laser cutting, milling, chemical machining or like
process. The surgical site is stabilized by applying a suitable
stabilizing force to stabilizer feet 305 and 306, which engage the
heart at tissue contacting regions 308, by way of stabilizing shaft
315. Stabilizing shaft 315 maybe connected to central base housing
330 using any connection which provides the desired maneuverability
of stabilizer feet 305 and 306 relative to stabilizing shaft 315.
In one embodiment, stabilizing shaft 315 is operably connected to
central base housing 330 by way of a malleable link 325 which is
allows the orientation of the stabilizer feet to be manually
oriented, but is sufficiently rigid to provide the required
stabilization of the surgical site. In another embodiment,
stabilizing shaft 315 may be connected to central base housing 330
using a suitable ball and socket joint as set forth above with
respect to FIG. 5.
[0076] Flexible member 310 is preferably articulated using tension
members 318 routed through guide tubes 326 and 328 which are
connected proximally to stabilizer shaft 315. Guide tubes 326 and
328 are preferably sufficiently flexible or malleable to follow
stabilizer feet 305 and 306 in and out without adversely effecting
the operation of tension members 318. The proximal ends of tension
members 318 may be connected to any suitable device that allows for
convenient tensioning to produce the desired articulation of
flexible member 310. Preferably, the proximal ends of tension
members 318 are connected to rotating spools 322 and 324 affixed to
collar 320 on stabilizer shaft 315.
[0077] Another tissue stabilizer embodiment having adjustable
stabilizer feet is illustrated in FIGS. 10-13. Tissue stabilizer
400 has first and second stabilizer feet 401 and 402 operably
connected to manifold base 420. Stabilizer feet 401 and 402
preferably have features for engaging the surface of the heart to
facilitate stabilization of at least a portion of the heart. In a
preferred embodiment, stabilizer feet 401 and 402 are connected to
manifold base 420 in a manner which allows each foot to
independently rotate relative to the manifold base 420. The axes
about which stabilizer feet 401 and 402 rotate may be in any
orientation that provides the desired stabilizer feet orientation
relative to the heart to achieve optimum engagement or tissue
presentation. Preferably, the axes are offset vertically from the
features which engage the surface of the heart. Suitable tissue
stabilizer constructions having rotatable stabilizer feet are
described in co-pending U.S. patent application Ser. No.
09/366,190, filed on Jun. 21, 1999 and titled "TISSUE STABILIZER
AND METHODS OF USE", the entirety of which is herein incorporated
by reference.
[0078] Referring to FIG. 11, a preferred stabilizer foot connection
is illustrated with respect to stabilizer foot 402. Manifold base
420 has a bore 452 extending through an exterior wall. Stabilizer
foot 402 has an end portion or fitting 450 having an outside
diameter adapted to mate with bore 452 to allow fitting 450, and
thus stabilizer foot 402, to rotate about central axis 455 of
fitting 450. When stabilizer feet 401 and 402 are rotatable in this
manner, their orientation may be adjusted to account for anatomical
differences to obtain the best possible engagement against the
surface of the tissue to be stabilized.
[0079] Preferably, central axis 455 is offset vertically from the
features on the stabilizer feet which engage the surface of the
heart. This offset facilitates a measure of improved vessel
presentation as stabilizer feet 401 and 402 are rotated because, in
addition to changing the overall orientation of the tissue engaging
features, the eccentric relation of the tissue engagement features
relative to central axis 455 moves the stabilizer feet together or
apart as the stabilizer feet are rotated. This action allows the
tissue and included target artery between the stabilizer feet to be
stretched or compressed as desired by rotating either or both of
stabilizer feet 401 and 402 after they have become operably engaged
with the tissue.
[0080] In a preferred embodiment, tissue stabilizer 400 is
constructed to supply a negative pressure or vacuum to stabilizer
feet 401 and 402 to assist in the engagement of the surface of the
heart. Stabilizer feet 401 and 402 preferably have a vacuum chamber
460 to which a vacuum may be supplied through vacuum inlet 451 of
fitting 455. Vacuum inlet 451 is in fluid communication with a
hollow interior chamber or space 457 within manifold base 420 to
which negative pressure may be supplied by way of barbed exterior
fitting 426.
[0081] To allow vacuum to be communicated from manifold base 420 to
the engagement features of stabilizer feet 401 and 402, the
rotating connection between stabilizer feet 401 and 402 and
manifold base 420 must be sealed to prevent any significant vacuum
loss. This is preferably accomplished using an appropriate dynamic
annular or shaft seal that seals between the stabilizer feet and
manifold base 120 but yet allows for rotation of the stabilizer
foot within bore 452 without incurring any vacuum loss. Preferably,
O-ring 445 is positioned within an annular seal cavity 448 at the
entrance of bore 452. O-ring 445 is captured and compressed within
seal cavity 448 by cooperating annular seal flange 447 provided on
stabilizer feet 401 and 402 as the stabilizer feet are urged into
final position. Stabilizer feet 401 and 402 may be held in position
by operation of an external retaining clip 454 assembled to fitting
450 just beyond its exit of bore 452.
[0082] Vacuum chamber 460 is generally a closed chamber except for
one or more openings for engaging the surface of the heart.
Preferably, stabilizer feet 401 and 402 have a substantially
continuous perimeter sealing member 462 for engaging the surface of
the heart. When perimeter sealing member 462 makes contact with the
surface of the heart around substantially its entire perimeter, the
portion of the heart tissue within the perimeter is subjected to
the negative pressure existing within vacuum chamber 460 and is
urged into engagement with stabilizer feet 401 and 402. The
negative or vacuum pressure may be sufficient to displace that
portion of heart tissue with the vacuum chamber created by
perimeter sealing member 462 into forced contact with perforated
sheet member 465 having holes or openings 466.
[0083] For ease of manufacturing and assembly, manifold base 420 is
preferably made in two or more portions and fixed together to form
the sealed, hollow interior space 420. In a preferred embodiment,
manifold base 420 has front manifold portion 422 and rear manifold
portion 424 which may be fixed together using standard mechanical
fasteners, a snap fit construction, or any suitable adhesive,
bonding, sealing or welding technique compatible with the material
of manifold base 420. Manifold base 420 is preferably made from an
injection molded plastic suitable for surgical sterilization.
[0084] To facilitate reliable bonding between front and rear
manifold portions 422 and 424, rear manifold portion 424 has an
inner flange 469 and front manifold portion 422 has an overlapping
outer flange 468. This overlapping flange configuration provides a
reliable seal between manifold portions, especially when used in
conjunction with a suitable gap-filling adhesive or bonding
agent.
[0085] Similar to the previously discussed embodiments, stabilizer
feet 401 and 402 have lo flexible members 405 and 406 which may be
elastically manipulated using attached tension members 430 to aid
in the surgical presentation of the tissue structure on which a
surgical procedure is to be performed. Flexible members 405 and 406
preferably define a vacuum space 412 for engaging the target artery
or surrounding tissue. Flexible members 405 and 406 are centrally
disposed relative to stabilizer feet 401 and 402 and preferably
have a curved outer profile having the greatest extension near its
center region. A curved configuration provides the greatest
manipulation of the target artery at the center and leaving the
ends of the arteriotomy somewhat less obstructed for improved
access.
[0086] Vacuum space 412 is supplied negative pressure from vacuum
chamber 460 through opening or aperture 410. The aperture is
preferably sized to restrict the amount of vacuum flow so that
vacuum chamber 460 is able to continue to hold the necessary vacuum
to maintain engagement and stabilization in the event a leak
develops around sealing edge 411 of flexible members 405 or 406. In
a preferred embodiment, at least a portion of stabilizer feet 401
and 402 is made from a clear material to aid in visually
determining if any portion of the perimeter seals have a vacuum
leak by observing blood or other material being sucked into vacuum
chamber 460 or vacuum space 412.
[0087] Instead of engaging the tissue using negative pressure
communicated through perforated sheet 465 the tissue stabilizer may
be provided with stabilizer feet having a tissue contacting surface
for frictionally engaging the surface of the heart. Referring to
FIG. 14, stabilizer foot 500 is constructed essentially similar to
stabilizer feet 401 and 402 except that stabilizer foot 500 has a
solid tissue contacting surface 505, preferably having a roughened
texture which may include a number of projections 508 for
increasing the lateral grip against the surface of the heart.
Stabilizer foot 500 has a sealed, hollow interior 502 which
accumulates negative pressure for communication to vacuum space 412
through opening or aperture 410.
[0088] As mentioned above, tension members 430 may be used to
articulate moveable members 405 and 406. Tension members 430 may be
routed proximally in or along a stabilizing shaft (not shown) which
is preferably operably connected at ball 428 extending from
manifold base 420 and may be connected to a tensioning mechanism
located on the shaft. In another embodiment, tensioning members 430
may be tensioned manually using forceps or the like until the
desired manipulation of moveable members 405 and 406 has been
achieved and then locked into place using a suitable thread locking
mechanism, spring, clip, clamp, or the like.
[0089] In a preferred embodiment illustrated in FIG. 10, stabilizer
feet 401 and 402 have suture locking devices for holding the
desired tension or position of tension members 430. Preferably
stabilizer feet 401 and 402 have channels 431 and 432 for receiving
tension members 430 and cavities 436 and 435 for receiving suture
locking members 440.
[0090] Suture locking members 440, best seen in FIG. 15, have a
pivot end 444 which fits snugly within cavities 436 and 435 and a
free end 441 which is biased against an inner wall of channels 431
and 432 to resist relaxation of tension member 430. Suture locking
member 440 is at an angle 442 relative to the channels 431 and 432
which allows body 443 and free end 441 to flex or pivot to allow
tension members 430 to be effortlessly pulled in a direction
towards the outside of stabilizer feet 401 and 402 and yet prevents
relaxation of tension members 430. The bias of free end 441 may be
increased by including a spring or resilient material 439. One or
more ridges or teeth may be provided on free end 441 to provide an
improved grip against tension members 430.
[0091] Another device for articulating the moveable portions is
illustrated in FIG. 16. Tissue stabilizer 550 has stabilizer foot
560 rotatably connected to manifold base 555 as discussed above.
Stabilizer foot 560 has a moveable portion 562 which has a link or
tension member 566 connected at attachment boss 564. Stabilizer
foot 560 has a post 572 over which pivot member 570 is installed.
Tension member 566 is attached to pivot member 570 at attachment
point 574 such that rotation of pivot member 570 about post 572
causes tension member 566 to articulate moveable portion 562 as
desired. In a preferred embodiment, pivot member 570 has an
extension 576 which cooperates with detents 578 in stabilizer foot
560. Thus, pivot member 570 detents into place in predetermined
increments as pivot member 570 is rotated to cause the desired
articulation of moveable member 560. Thus pivot member 570 will
hold a desired position within any of detents 578 for as long as
required by the procedure.
[0092] In a preferred method of using a tissue stabilizer having
independently rotatable feet, the tissue stabilizer is placed over
the desired target coronary artery such that each stabilizer foot
is positioned on opposite sides of a target vessel. The stabilizer
feet are engaged against the surface of the heart using
compression, negative pressure, or both to stabilize a portion of
the heart under the stabilizer feet. When the stabilizer feet are
constructed to engage the surface of the heart using negative
pressure, one or both of the stabilizer feet may be adjusted to
achieve a good seal against the heart or to cause the desired
manipulation of the heart tissue. Preferably, the stabilizer feet
may be independently adjusted by rotating one or both of the
stabilizer feet relative to each other.
[0093] Preferably, negative pressure is also communicated to
flexible members 405 and 406, causing them to become engaged with a
portion of the target artery or surrounding tissue. An arteriotomy
is then formed in the target artery at a desired location for
anastomosing a graft or source vessel. The surgical site and
arteriotomy can be manipulated using the stabilizer foot to obtain
an optimal presentation. For example, the stabilizer feet can be
rotated in opposite directions (one counter-clockwise and the other
clockwise) to cause the tissue closest to the target artery to be
pressed downward or lifted upwards. Also, the stabilizer feet can
be rotated it the same direction to differentially cause upward
lifting on one side of the target artery and downward pressing on
the other.
[0094] The stabilizer feet may be independently adjusted using any
suitable instrument. Indentations, protrusions, polygonal flats, or
the like may be provided on one or both of the stabilizer feet to
facilitate secure instrument engagement for positioning. If
desired, the stabilizer feet may be mechanically coupled to each
other by way of a gears, belts, or linkages such that movement of
one stabilizer foot causes a corresponding movement in the other.
Further, the stabilizer feet or coupling mechanism may be operably
connected to a remote actuator by a tension wire, drive cable,
linkage or the like to facilitate remote actuation of the
stabilizer feet.
[0095] In addition to the overall adjustment of each stabilizer
foot, one or both of the flexible members 405 and 406 can be
articulated relative to the stabilizer feet. In a preferred
embodiment, flexible members 405 and 406 are articulated to lift
open one or both sides of the arteriotomy incised in the target
artery. Preferably, flexible members 405 and 406 are articulated by
pulling on tension wires attached thereto using forceps or other
suitable instrument or mechanism. Once the arteriotomy has been
presented as desired one or more sutures can then be safely and
accurately placed. The target site may be adjusted as desired
throughout the anastomosis procedure to maintain optimal
presentation of the tissue to be sutured.
[0096] While certain embodiments are illustrated in the drawings
and have just been described herein, it will be apparent to those
skilled in the art that many modifications can be made to the
embodiments without departing from the inventive concepts
described. For purposes of illustration only, the principles of the
present invention has been described with reference to stabilizing
the heart during a coronary artery bypass procedure but may readily
be applied to other types surgical procedures on various types of
tissue structures not specifically described. Many other uses are
well known in the art, and the concepts described herein are
equally applicable to those other uses. Further, the different
components of the various exemplar embodiments described above can
be combined in any desirable construction. Accordingly, the
invention is not to be restricted except by the claims which
follow.
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