U.S. patent application number 13/357456 was filed with the patent office on 2012-05-17 for bridge clip tissue connector apparatus and methods.
This patent application is currently assigned to MEDTRONIC, INC. Invention is credited to Nga Doan, Liem Ho, John D. Nguyen, Laurent Schaller, Cong Thach.
Application Number | 20120123449 13/357456 |
Document ID | / |
Family ID | 25251468 |
Filed Date | 2012-05-17 |
United States Patent
Application |
20120123449 |
Kind Code |
A1 |
Schaller; Laurent ; et
al. |
May 17, 2012 |
BRIDGE CLIP TISSUE CONNECTOR APPARATUS AND METHODS
Abstract
A novel bridge clip tissue connector includes two clips
separated by a bridge portion. The clips allow for the connecting
of tissue at two positions that are maintained by the bridge
portion. The connector can be used for performing a wide variety of
surgical procedures, including anastomosis and a horizontal
mattress suture-like connection.
Inventors: |
Schaller; Laurent; (Los
Altos, CA) ; Nguyen; John D.; (San Jose, CA) ;
Ho; Liem; (Mountain View, CA) ; Doan; Nga;
(San Jose, CA) ; Thach; Cong; (San Jose,
CA) |
Assignee: |
MEDTRONIC, INC
Minneapolis
MN
|
Family ID: |
25251468 |
Appl. No.: |
13/357456 |
Filed: |
January 24, 2012 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09828322 |
Apr 5, 2001 |
8118822 |
|
|
13357456 |
|
|
|
|
09260623 |
Mar 1, 1999 |
6613059 |
|
|
09828322 |
|
|
|
|
Current U.S.
Class: |
606/151 |
Current CPC
Class: |
A61B 2017/06057
20130101; A61B 2017/00867 20130101; A61B 17/064 20130101; A61B
2017/06009 20130101; A61B 17/0469 20130101; A61B 17/06004 20130101;
A61B 2017/1135 20130101; A61B 17/11 20130101; A61B 17/06 20130101;
A61B 2017/1107 20130101; A61B 17/0644 20130101 |
Class at
Publication: |
606/151 |
International
Class: |
A61B 17/03 20060101
A61B017/03 |
Claims
1. A surgical method to attach tissue comprising: positioning two
piercing ends of a fastener near one side of a first tissue at a
piercing distance, where said fastener includes two clips each
having an open configuration and a closed configuration, and a
bridge portion joining said two clips, where said bridge portion
spaces said two clips a clipping distance when in said closed
configuration, and where said piercing distance is approximately
equal to said clipping distance; piercing said first tissue with
said piercing ends with said two clips in said open configuration;
positioning said bridge along said one side; piercing a second
tissue with said two clips in said open configuration; drawing said
clips in said open configuration through said second tissue; and
actuating said release mechanism.
2. The method of claim 1, wherein said self-closing clip includes a
shape memory material.
3. The method of claim 1, wherein said first tissue is the heal or
toe of a graft vessel, wherein said second tissue is a target
vessel, and wherein said drawing includes parachuting said first
tissue onto said second tissue, and wherein said actuating joins
said first and second tissue to form an anastomosis.
4. The method of claim 1, wherein said actuating joins said first
and second tissue to form a horizontal mattress suture.
Description
CROSS-REFERENCE TO RELATED DOCUMENTS
[0001] The present application is a continuation-in-part of
copending patent application Ser. No. 09/260,623, filed Mar. 1,
1999.
FIELD OF THE INVENTION
[0002] The present invention relates to instruments and methods for
connecting body tissues, tissue and prostheses, tissue and graft or
any combination thereof.
BACKGROUND OF THE INVENTION
[0003] Minimally invasive surgery has allowed physicians to carry
out many surgical procedures with less pain and disability than
conventional, open surgery. In performing minimally invasive
surgery, the surgeon makes a number of small incisions through the
body wall to obtain access to the tissues requiring treatment.
Typically, a trocar, which is a pointed, piercing device, is
delivered into the body with a cannula. After the trocar pierces
the abdominal or thoracic wall, it is removed and the cannula is
left with one end in the body cavity, where the operation is to
take place, and the other end opening to the outside. A cannula has
a small inside diameter, typically 5-10 millimeters, and sometimes
up to as much as 20 millimeters. A number of such cannulas are
inserted for any given operation.
[0004] A viewing instrument, typically including a miniature video
camera or optical telescope, is inserted through one of these
cannulas and a variety of surgical instruments and refractors are
inserted through others. The image provided by the viewing device
may be displayed on a video screen or television monitor, affording
the surgeon enhanced visual control over the instruments. Because a
commonly used viewing instrument is called an "endoscope," this
type of surgery is often referred to as "endoscopic surgery." In
the abdomen, endoscopic procedures are commonly referred to as
laparoscopic surgery, and in the chest, as thoracoscopic surgery.
Abdominal procedures may take place either inside the abdominal
cavity (in the intraperitoneal space) or in a space created behind
the abdominal cavity (in the retroperitoneal space). The
retroperitoneal space is particularly useful for operations on the
aorta and spine, or abdominal wall hernia.
[0005] Minimally invasive surgery has virtually replaced open
surgical techniques for operations such as cholecystectomy and
anti-reflux surgery of the esophagus and stomach. This has not
occurred in either peripheral vascular surgery or cardiovascular
surgery. An important type of vascular surgery is to replace or
bypass a diseased, occluded or injured artery. Arterial replacement
or bypass grafting has been performed for many years using open
surgical techniques and a variety of prosthetic grafts. These
grafts are manufactured as fabrics (often from DACRON.RTM.
(polyester fibers) or TEFLON.RTM. (fluorocarbon fibers)) or are
prepared as autografts (from the patient's own tissues) or
heterografts (from the tissues of animals) or a combination of
tissues, semi-synthetic tissues and or alloplastic materials. A
graft can be joined to the involved artery in a number of different
positions, including end-to-end, end-to-side, and side-to-side.
This attachment between artery and graft is known as an
anastomosis. Constructing an arterial anastomosis is technically
challenging for a surgeon in open surgical procedures, and is
almost a technical impossibility using minimally invasive
techniques.
[0006] Many factors contribute to the difficulty of performing
arterial replacement or bypass grafting. See generally, Wylie,
Edwin J. et al., Manual of Vascular Surgery, (Springer-Verlag New
York), 1980. One such factor is that the tissues to be joined must
be precisely aligned with respect to each other to ensure the
integrity and patency of the anastomosis. If one of the tissues is
affixed too close to its edge, the suture can rip through the
tissue and impair both the tissue and the anastomosis. Another
factor is that, even after the tissues are properly aligned, it is
difficult and time consuming to pass the needle through the
tissues, form the knot in the suture material, and ensure that the
suture material does not become tangled. These difficulties are
exacerbated by the small size of the artery and graft. The arteries
subject to peripheral vascular and cardiovascular surgery typically
range in diameter from several millimeters to several centimeters.
A graft is typically about the same size as the artery to which it
is being attached. Another factor contributing to the difficulty of
such procedures is the limited time available to complete the
procedure. The time the surgeon has to complete an arterial
replacement or bypass graft is limited because there is no blood
flowing.
[0007] through the artery while the procedure is being done. If
blood flow is not promptly restored, sometimes in as little as
thirty minutes, the tissue the artery supplies may experience
significant damage, or even death (tissue necrosis). In addition,
arterial replacement or bypass grafting is made more difficult by
the need to accurately place and space many sutures to achieve a
permanent hemostatic seal. Precise placement and spacing of sutures
is also required to achieve an anastomosis with long-term
patency.
[0008] Highly trained and experienced surgeons are-able to perform
arterial replacement and bypass grafting in open surgery using
conventional sutures and suturing techniques: A suture has a suture
needle that is attached or "swaged on" to a long, trailing suture
material. The needle must be precisely controlled and accurately
placed through both the graft and artery. The trailing suture
material must be held with proper tension to keep the graft and
artery together, and must be carefully manipulated to prevent the
suture material from tangling. In open surgery, these maneuvers can
usually be accomplished within the necessary time frame, thus
avoiding the subsequent tissue damage (or tissue death) that can
result from prolonged occlusion of arterial blood flow.
[0009] A parachuting technique may be used to align the graft with
the artery in an end-to-side anastomosis procedure. One or multiple
sutures are attached to the graft and artery and are used to pull
or "parachute" the graft vessel into alignment with an opening
formed in a sidewall of the artery. A drawback to this procedure is
the difficulty in preventing the suture from tangling and the time
and surgical skill required to tie individual knots when using
multiple sutures. Due to space requirements, this procedure is
generally limited to open surgery techniques.
[0010] The difficulty of suturing a graft to an artery using
minimally invasive surgical techniques has effectively prevented
the safe use of this technology in both peripheral vascular and
cardiovascular surgical procedures. When a minimally invasive
procedure is done in the abdominal cavity, the retroperitoneal
space, or chest, the space in which the operation is performed is
more limited, and the exposure to the involved organs is more
restricted, than with open surgery. Moreover, in a minimally
invasive procedure, the instruments used to assist with the
operation are passed into the surgical field through cannulas. When
manipulating instruments through cannulas, it is extremely
difficult to position tissues in their proper alignment with
respect to each other, pass a needle through the tissues, form a
knot in the suture material once the tissues are aligned, and
prevent the suture material from becoming tangled. Therefore,
although there have been isolated reports of vascular anastomoses
being formed by minimally invasive surgery, no system has been
provided for wide-spread surgical use which would allow such
procedures to be performed safely within the prescribed time
limits.
[0011] As explained above, anastomoses are commonly formed in open
surgery by suturing together the tissues to be joined. However, one
known system for applying a clip around tissues to be joined in an
anastomosis is disclosed in a brochure entitled, "VCS Clip Applier
System", published in 1995 by Auto Suture Company, a Division of
U.S. Surgical Corporation. A clip is applied by applying an
instrument about the tissue in a non-penetrating manner, i.e., the
clip does not penetrate through the tissues, but rather is clamped
down around the tissues. As previously explained, it is imperative
in forming an anastomosis that tissues to be joined are properly
aligned with respect to each other. The disclosed VCS clip applier
has no means for positioning tissues. Before the clip can be
applied, the tissues must first be properly positioned with respect
to each other, for example by skewering the tissues with a needle
as discussed above in common suturing techniques or with forceps to
bring the tissues together. It is extremely difficult to perform
such positioning techniques in minimally invasive procedures.
[0012] Therefore, there is currently a need for other tissue
connecting systems.
SUMMARY OF THE INVENTION
[0013] The present invention involves apparatus and methods for
connecting material, at least one of which is tissue. The invention
may, for example, be used to secure one vessel to another, such as
in a vascular anastomosis.
[0014] According to one aspect of the invention, a tissue connector
assembly is provided comprising a surgical fastener, such as a
surgical clip, a first tissue-piercing member and a second
tissue-piercing member. The fastener may be adapted to assume a
loop configuration. The fastener has a first end portion and a
second end portion. The first tissue-piercing member is coupled to
the first end portion and the second tissue-piercing member is
coupled to the second end portion. The multiple piercing member
construction facilitates threading ends of the assembly from inner
to outer Walls of material, such as tissue, which may eliminate or
minimize the possibility of dislodging material from the inner wall
of a vessel, for example.
[0015] According to another aspect of the invention, a flexible
member, such as a suture, may be provided between at least one
piercing member and the fastener to facilitate threading the
fastener and/or "parachute" techniques, for example.
[0016] According to another aspect of the invention, synchronized
piercing member release mechanisms may be provided. In one
embodiment, the tissue connector assembly may include a first
coupling, which couples the first tissue piercing member and first
end portion of the surgical fastener, and a second coupling, which
couples the surgical fastener second end portion and second
piercing member. The first coupling releases the other coupling in
response to releasing the first coupling. According to one aspect
of this embodiment, multiple tissue piercing members may be
decoupled from the surgical fastener with one release actuator.
According to another aspect, the piercing members may be decoupled
essentially simultaneously.
[0017] According to yet another aspect of the invention, a tissue
connector assembly is provided for joining tissues as a "bridge
clip" that includes a surgical fastener having two surgical clips
connected by a bridge. In one embodiment the two clips are biased
into an open configuration, and can close through a release
mechanism. In an alternative embodiment, each clip has one release
mechanism and one coil surrounding the clip to individually bias
the clips in an open configuration. In yet another alternative
embodiment, each clip has one release mechanism, and a single: coil
is connected to both release mechanisms to bias both clips. In a
preferred embodiment, each clip is attached to a piercing member
through a length of a flexible member.
[0018] According to another aspect of the present invention a
tissue connector assembly is provided for attaching tissue. In one
embodiment the assembly includes a surgical fastener having two
self-closing clips separated by a bridge portion and a release
mechanism to actuate the self-closing clips. Another embodiment
provides a surgical fastener having two clips, at least one of
which is self-closing, separated by a bridge portion and coupled to
tissue piercing members.
[0019] According to another aspect of the invention, a bridge clip
is provided to facilitate attaching tissue using a technique such
as parachuting. With both clips in the open configuration and
attached to their respective piercing member, each piercing member
is used to pierce one side of a tissue, effectively positioning the
bridge against the tissue. After a second set of piecings on a
second tissue, the first tissue can be guided onto the second
tissue. With the clips threaded through both tissues, the release
mechanism is actuated, securing the two tissues at two slightly
displaced locations. In yet another aspect of the invention, a
bridge clip is provided to attach tissues using a technique similar
to a horizontal mattress suture.
[0020] The above is a brief description of some deficiencies in the
prior art and advantages of the present invention. Other features,
advantages, and embodiments of the invention will be apparent to
those skilled in the art from the following description,
accompanying drawings, and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a perspective of a tissue connector assembly
constructed in accordance with the principles of the present
invention;
[0022] FIG. 2A is a partial sectional view illustrating an
alternate construction of flexible member 18 of FIG. 1;
[0023] FIG. 2B is a partial sectional view illustrating yet another
construction of flexible member 18 of FIG. 1;
[0024] FIGS. 3A, 3B and 3C show a fastener which can be used with
the tissue connector assembly of FIG. 1, where FIG. 3A is a top
view of the fastener in a closed position, FIG. 3B is a side view
of the fastener of FIG. 3A, and FIG. 3C is an enlarged view of the
fastener of FIG. 3A in an open position;
[0025] FIG. 4 is a top view of another fastener configuration,
which can be used with the tissue connector assembly of FIG. 1;
[0026] FIGS. 5A and 5B show yet another fastener configuration
which can be used with the tissue connector assembly of FIG. 1,
where FIG. 5A shows the fastener in a closed position and FIG. 5B
is a side view of the fastener of FIG. 5A;
[0027] FIG. 6 is top view of yet a further configuration of a
fastener that can be used with the tissue connector assembly of
FIG. 1 with the fastener in a closed position;
[0028] FIGS. 7A, 7B and 7C illustrate a release mechanism which can
be used with any of the fasteners described above and the tissue
connector assembly of FIG. 1, where FIG. 7A shows the restraining
device in cross-section and in a locked position, FIG. 7B is a
transverse cross-sectional view of the restraining device taken in
a plane along line 7B-7B of FIG. 7A, and FIG. 7C is a
cross-sectional view of the restraining device of FIG. 7A in an
unlocked position;
[0029] FIGS. 8A, 8B and 8C illustrate another release mechanism
which can be used with any of the fasteners described above and the
tissue connector assembly of FIG. 1, where FIG. 8A shows the
restraining device in cross-section and in a locked position, FIG.
8B is a transverse cross-sectional view of the restraining device
taken in a plane along line 8B-8B of FIG. 8A, and FIG. 8C is a
cross-sectional view of the restraining device of FIG. 8A in an
unlocked position;
[0030] FIGS. 9A-9E illustrates yet another release mechanism which
can be used with any of the fasteners described above, where FIG.
9A shows a perspective view of the retaining device coupled with a
fastener, FIG. 9B is a sectional view of the retaining device of
FIG. 9A, FIG. 9C is a transverse cross-sectional view of the
restraining device taken along line 9C-9C in FIG. 9B, FIGS. 9D and
9E are perspective and end views of the restraining device,
respectively, showing the device depressed for release of the
fastener; and FIG. 9F shows the retaining device of FIG. 9A with an
adapter for coupling to the other end of the fastener;
[0031] FIGS. 10A-10C show a synchronized fastener release system,
where FIGS. 10A and 10C are partial sectional views of the system
in a coupled and decoupled state, respectfully, and FIG. 10B is a
sectional view taken along lines 10B-10B in FIG. 10A;
[0032] FIGS. 10D-10F show another synchronized fastener release
system where FIGS. 10D and 10E are partial sectional views of the
system in a coupled and decoupled state, respectfully, and FIG. 10F
is a transverse cross-sectional view taken along line 10E-10F in
FIG. 10E;
[0033] FIGS. 11A and 11B are partial sectional views of another
piercing member and/or suture release mechanism in a coupled and
decoupled state, respectfully;
[0034] FIGS. 12A and 12B are partial sectional views of a further
piercing member and/or suture release mechanism in a coupled and
decoupled state, respectfully;
[0035] FIGS. 13A and 13B are partial sectional views of yet another
piercing member and/or suture release mechanism in a coupled and
decoupled state, respectfully;
[0036] FIG. 14A is a front view of a another embodiment of a tissue
connector assembly of the present invention;
[0037] FIG. 14B is a sectional view of a piercing member and
release mechanism combination, which can be used in the embodiment,
illustrated in FIG. 14A;
[0038] FIG. 15 is a front view of a lateral tissue connector, which
can be used in conjunction with any of the assemblies described
above;
[0039] FIGS. 16A-16D diagrammatically illustrate a method of
aligning and connecting graft and target vessels with the tissue
connector assembly of FIG. 1, where FIG. 16A shows two such tissue
connector assemblies threaded through a graft and target vessel,
FIG. 16B shows a further step in connecting the graft and target
vessel with the tissue connector assembly fastener is positioned in
the target vessel, FIG. 16C shows yet a further step where the
graft has been brought into position over the opening formed in the
target vessel and the tissue connector assembly fastener positioned
through the walls of the graft and target vessel and FIG. 16D shows
the fasteners released from the tissue connector assembly of FIG. 1
and securing the graft and target vessel together with additional
laterally disposed fasteners;
[0040] FIG. 16E is a partial sectional view of the graft and target
vessels with the tissue connector assembly fasteners of FIG. 1 in
place prior to placement of additional lateral fasteners;
[0041] FIG. 16F is an enlarged view of the tissue connection within
line 16F of FIG. 16E;
[0042] FIG. 17 is a perspective of a bridge clip tissue connector
assembly of the present invention;
[0043] FIG. 18 is a perspective view of the fastener of FIG. 17, in
which the fastener has been released from the tissue connector
assembly and is in a closed position;
[0044] FIGS. 19A-19C diagrammatically illustrate a method of
approximating graft and target vessels with the tissue connector
assemblies of FIGS. 1 and 17, where FIG. 19A shows the tissue
connector assembly of FIG. 17 threaded through the toe of a graft
vessel and target vessel union, FIG. 19B shows a further step in
connecting the graft and target vessels with the fastener of FIG.
17 connecting the toe of the graft and three connector assemblies
of FIG. 1 in various states of connecting the graft and target
vessels, and FIG. 19C shows yet a further step where tissue
connector assemblies of FIG. 1 are shown securing the remainder of
the vessel edges; and
[0045] FIG. 20A-20B are a top and side view, respectively, of a
bridge clip as used as a horizontal mattress suture.
[0046] Corresponding reference characters indicate corresponding
elements throughout the drawings.
DESCRIPTION OF THE INVENTION
[0047] The present invention generally involves methods and devices
for manipulating, aligning and/or connecting tissues, tissue and
prosthesis, tissue and graft, or any combination thereof. As used
herein, the term graft includes any of the following: homografts,
autologous grafts, xenografts, allografts, alloplastic materials,
and combinations of the foregoing. Tissue connector assemblies are
disclosed, which, for example, may be used in vascular surgery to
replace or bypass a diseased, occluded, or injured artery by
connecting a graft vessel to a coronary artery or vein in an
anastomosis as shown in FIGS. 16A-F or in FIGS. 19A-C. Assemblies
constructed in accordance with the invention may be used in open
surgical procedures or in minimally invasive or endoscopic
procedures for attaching tissue located in the chest, abdominal
cavity, or retroperitoneal space. It should be understood, however,
that these examples are provided for illustration and are not
intended to limit the scope of the invention.
[0048] Tissue connecting assemblies and methods are disclosed in
copending U.S. patent application Ser. Nos. 09/089,884 and
09/090,305, both entitled Tissue Connector Apparatus and Methods
and having a filing date of Jun. 3, 1998. The entirety of the
disclosures of the cited '884 and '305 applications is hereby
incorporated herein. One aspect of the present invention is the
provision of multiple tissue piercing members. More specifically,
tissue connecting assemblies constructed according to the present
invention generally include a plurality of tissue piercing or
penetrating members coupled to a surgical fastener. The multiple
piercing member construction facilitates threading ends of the
assembly from inner to outer wall(s) of material, such as tissue,
which may eliminate or minimize the possibly of dislodging
material, such as plaque, from the inner wall of calcified
arteries, for example, as will become more apparent from the
description provided below. In a preferred embodiment, two piercing
members, each of which may comprise a needle, are releasably
coupled to a fastener. One or both of the piercing members may be
attached to a flexible member, such as a suture, which in turn is
releasably coupled to the fastener. Double and single flexible
member embodiments are illustrated in FIGS. 1 and 14, respectively.
The coupling between the flexible member (and, thus, the piercing
member) and the fastener may be constructed to actuate closure of
the fastener upon release of the flexible member (or piercing
member). For example, the coupling may hold a compression spring
(which is positioned around a fastener) in a compressed state to
brace the fastener open and releasably lock or secure the fastener
to the flexible member (or piercing member).
[0049] A second double flexible member embodiment, also known as a
dual clip assembly or as a bridge clip assembly, is illustrated in
FIG. 17. This embodiment differs from the previous embodiments in
that the fastener includes two clips separated by a bridge portion.
Each clip is releasably attached to one flexible member and one
piercing member. The biasing of each of the clips and the
releasable coupling of the clips to the flexible member is similar
to that of the previous embodiments. The fastener of this
embodiment is particularly useful in facilitating tissue
attachments, such as in guiding and aligning one tissue for
attachment to a second tissue or for performing a horizontal
mattress suture.
[0050] FIG. 1 illustrates one embodiment of a tissue connector
assembly in accordance with the present invention. Referring to
FIG. 1, a tissue connector assembly 11, which generally comprises
tissue piercing or penetrating members 16 and 17, flexible members
18 and 19, and a fastener 20 (e.g., a surgical clip) is shown. A
restraining device, generally indicated at 24 and comprising a
spring (or coil) 26 and a locking device (or coupling member)
generally indicated at 28, is connected to fastener 20 for holding
the fastener in a deformed or open configuration as will be further
described below. Although a particular fastener and accompanying
restraining device is shown in FIG. 1, it should be understood that
any suitable fastener can be used, including but not limited to the
alternate fastener configurations described below. For example, the
fastener may be a plastically deformable clip or may comprise two
or more parts, at least one of which is movable relative to the
other part, such as with a hinged clip. Further, other piercing
member release mechanisms can be used with or without restraining
devices depending on the fastener construction.
[0051] Each of penetrating or piercing members 16 and 17 may be in
the form of a needle (such as a 7-0 or 8-0 needle) having a sharp
pointed tip (30 or 31) at its distal end for penetrating tissue.
Members 16 and 17 may be bent as shown in FIG. 1, for example. The
diameter of at least a portion of each of members 16 and 17 is
preferably greater than the diameter of the respective flexible
members (18 and 19), coupled thereto so that the flexible members
can easily be pulled through an opening formed in the tissue (or
other material) by the needle. The distal ends of the members 16
and 17 are preferably rigid to facilitate penetration of tissue.
The remaining length of members 16 and 17 may be rigid or flexible
to facilitate movement of the needle through the tissue as further
described below. Tips 30 and/or 31 may have various configurations
and may, for example, be conical, tapered, or grounded to attain a
three or four facet tip. Members 16 and 17 may be made from
stainless steel or any other suitable material, such as a polymeric
material. It is to be understood that members 16 and 17 may have a
shape or radius of curvature other than the one shown, without
departing from the scope of the invention. Members 16 and 17 may
also be integrally formed with the flexible member 18 (e.g., both
piercing member and flexible member formed of the same
material).
[0052] The flexible members 18 and 19 may be in the form of a
suture formed from conventional filament material, metal alloy,
such as nitinol, polymeric material, or any other suitable
material. The material may be non-stretchable or stretchable, solid
or hollow (as shown, for example, in FIGS. 2A and 2B), and have
various cross-sectional diameters. The flexible members or sutures
may have a cross-sectional diameter of 0.003 inch, and lengths
ranging from about 10 mm to about 300 mm, for example. The diameter
and length of the suture will vary depending on the specific
application. The sutures may be attached to the piercing members 16
and 17, respectively, by crimping or swaging the piercing member or
needle onto the suture, gluing the suture to the piercing member or
needle, or any other suitable attachment method. Flexible members
18 and 19 may have cross-sectional shapes other than the one shown
herein and may have other constructions as well.
[0053] Referring to FIG. 2A, an alternate flexible member
construction is shown. Flexible member 18' generally comprises a
flexible filament 14, which may be in the form of a metal wire, and
tube or sleeve 15 which may be in the form of a hollow suture. Tube
15 surrounds filament 14 with one end of the filament 14 secured to
piercing member 16 and its other end secured to coupling 28 with
glue, for example. The filament may provide kink resistance and
pull strength (to minimize or eliminate stretch), and is especially
advantageous when using very thin material for tube 15. Tube 15
may, for example, comprise polymeric materials such as polyurethane
or polyester. It is noted that at least the portions of the tube
adjacent to needle 16 and coupling 28 have the same diameter as the
portions of the coupling and needle adjacent thereto. This
eliminates the need for the tapered portions 2 and 3 shown in FIG.
1 or other transition sections to minimize or eliminate the step
between the flexible member and needle and/or the flexible member
and the coupling. Of course, the diameter of the entire flexible
member may be the same as that of the coupling and the portion of
the needle adjacent to the flexible member as indicated in FIG. 2A.
It also should be apparent from the foregoing that the construction
of flexible member 18' may be substituted for flexible member
19.
[0054] Referring to FIG. 2B, another hollow flexible member
construction is shown. Flexible member 18'' comprises tube or
sleeve 15, which may be in the form of a hollow suture. Tube 15 is
secured to piercing member or needle 16 and coupling 28 through
posts or anchors 4, which in turn, are secured to piercing member
or needle 16 and coupling 28. The relative dimensions of tube 15 as
compared to needle 16 and coupling 28 may be the same as those
describe in connection with FIG. 2A for the same reasons. Further,
flexible member 18'' may be substituted for flexible member 19 as
well.
[0055] Referring to FIGS. 3-6, fasteners, which were shown in
copending U.S. patent application Ser. Nos. 09/089,884 and
09/090,305 and which may be used in the present invention, first
will be described. Referring to FIGS. 3A-C, one embodiment of a
fastener (e.g., fastener 20) comprises a deformable wire 34 made of
a shape memory alloy. A nickel titanium (nitinol) based alloy may
be used, for example. The nitinol may include additional elements
that affect the yield strength of the material or the temperature
at which particular pseudoelastic or shape transformation
characteristics occur. The transformation temperature may be
defined as the temperature at which a shape memory alloy finishes
transforming from martensite to austenite upon heating (i.e.,
A.sub.f temperature). The shape memory alloy preferably exhibits
pseudoelastic (e.g., superelastic) behavior when deformed at a
temperature slightly above its transformation temperature. At least
a portion of the shape memory alloy is converted from its
austenitic phase to its martensitic phase when the wire is in its
deformed configuration. As the stress is removed, the material
undergoes a martensitic to austenitic conversion and springs back
to its original undeformed configuration. When the wire is
positioned within the tissue in its undeformed configuration, a
residual stress is present to maintain the tissue tightly together
(see e.g., FIG. 16F). In order for the pseudoelastic wire 34 to
retain sufficient compression force in its undeformed
configuration, the wire should not be stressed past its yield point
in its deformed configuration to allow complete recovery of the
wire to its undeformed configuration. The shape memory alloy is
preferably selected with a transformation temperature suitable for
use with a stopped heart condition where cold cardioplegia has been
injected for temporary paralysis of the heart tissue (e.g.,
temperatures as low as 8-10 degrees Celsius).
[0056] It is to be understood that the shape memory alloy may also
be heat activated, or a combination of heat activation and
pseudoelastic properties may be used, as is well known by those
skilled in the art.
[0057] The cross-sectional diameter of wire 34 and length of the
wire will vary depending on the specific application. The diameter
"d" of wire 34 may be, for example, between 0.001 and 0.015 inch.
For coronary bypass applications, the diameter is preferably
between 0.001 and 0.008 inch with a diameter "D" of the loop (FIG.
3A) being between 0.0125 and 0.0875 inch. As shown in FIGS. 3A and
3B, wire 34 may have a circular cross-sectional shape and a
generally ring or loop shaped configuration when in a closed
position. The diameter "D" of the loop of the fastener 20 (with
coil 26, which may be platinum) in its closed position is
preferably sized to prevent movement between adjacent tissues. It
is to be understood, however, that the wire may have other
cross-sectional shapes such as rectangular, or may be formed from
multiple strands without departing from the scope of the
invention.
[0058] One end of wire 34, which may be referred to as the proximal
end of wire 34, may include an enlarged portion 36 having a
cross-sectional area greater than the cross-sectional area of the
wire to resist the coil from passing thereover. The enlarged
portion 36 also may be provided to cooperate with a release
mechanism as will be discussed in more detail below. Enlarged
portion 36 may be formed by attaching a member to the end of wire
34 by welding, gluing or other suitable attachment means or may be
formed integrally with the wire by deforming the end of the wire.
The other end of wire 34, which may be referred to as the distal
end of wire 34, also may include an enlarged portion 38 for
engagement with a restraining device, such as restraining device 24
(see. e.g., FIG. 1), or a locking device or release mechanism, such
as release mechanism 28 (see e.g., FIG. 1), as further described
below. The enlarged portion 38 may be formed by deforming the end
of the wire 34 by swaging or arc welding, or attaching an enlarged
portion to the end of the wire by welding, swaging, or other
suitable means. Although enlarged portions 36 and 38 are shown with
spherical and cylindrical configurations, other configurations or
configuration combinations can be used. For example, both enlarged
portions may be spherical or cylindrical, or portion 36 may be
cylindrical and portion 38 spherical.
[0059] Referring to FIGS. 3A-C, fastener 20 is shown in open and
closed configurations. When wire 34 is in an undeformed or closed
configuration, the fastener is closed (as shown in FIGS. 3A and 3B)
for keeping or connecting tissue together, and when wire 34 is in a
deformed or open configuration, the fastener is open (as shown in
FIG. 3C) for insertion of the wire into tissue. As discussed above,
wire 34 is in its closed configuration when in a relaxed state.
Wire 34 is preferably not deformed past its yield point in its open
position. Accordingly, it may have a U-shaped configuration in its
open position to facilitate insertion of the wire through the
tissue. It is to be understood that U-shaped configuration may be
alternatively substituted by an equivalent structure such as
C-shaped, V-shaped, J-shaped, and other similarly shaped
configurations. Wire 34 is moved from its closed position to its
open position by a restraining device, as further described below.
When in its closed position, wire 34 forms a loop with the ends of
the wire in a generally side-by-side or overlapping orientation
(FIG. 3B).
[0060] Wire 34 maybe formed in the above-described shape by first
wrapping the wire onto a mandrel and heat-treating the wire at
approximately 400-500 degrees Celsius for approximately 5 to 30
minutes. Wire 34 is then air quenched at room temperature. The
mandrel may have a constant diameter or may be conical in
shape.
[0061] Referring to FIG. 4, an alternate configuration of fastener
20 in its closed position is shown, and generally indicated with
reference numeral 40. Fastener 40 forms a spiral configuration in
its closed position for trapping the tissue within a loop formed by
the spiral. In its open position, the fastener 40 is configured to
form less than a full 360 degree turn, and may be made to have an
open position as shown in FIG. 3C, for example.
[0062] Referring to FIGS. 5A and 5B, another configuration of
fastener 20 is shown in its closed position, and is generally
designated with reference numeral 41. Fastener 41 is formed in a
spiral about a central longitudinal axis A. As shown in FIG. 5B,
fastener 41 has a generally conical shape along the longitudinal
axis A, with a decreasing diameter as the radius of curvature of
fastener 41 decreases. Fastener 41 has an inner end portion 45 and
an outer end portion 47, with the enlarged portion 38 of the wire
being disposed at the outer end portion for engagement with the
restraining device 24 as shown, for example, in FIG. 3C. Referring
to FIG. 6, a modification of fastener 41 is shown, and generally
indicated with reference numeral 43. Fastener 43 is similar to
fastener 41 described above, except that enlarged portion 38, which
is adapted for engaging a restraining device or releasable locking
mechanism, is positioned at the inner end portion 45 of the
fastener. Placement of restraining device 24 at the inner end
portion 45 of fastener 43 increases the compression force of the
wire in its undeformed position on the tissue and decreases the
surface area of the fastener exposed to blood flow.
[0063] It is to be understood that the fasteners may have
undeformed or deformed configurations different than those shown
herein without departing from the scope of the invention. In
addition, a locking clip (not shown) may also be attached to
connect the ends of the fastener (such as fastener 20, 40, 41, 43)
when the fastener is in its closed position to prevent possible
opening of the fastener over time. The locking clip may also be
integrally formed with one end of the fastener.
[0064] As shown in FIG. 3C, wire 34 is surrounded by spring or coil
26 that, along with the locking device 28, restrains the wire in
its deformed configuration. Coil 26 comprises a helical wire
forming a plurality of loops that define a longitudinal opening 44
for receiving the shape memory alloy wire 34. Coil 26 may be formed
from a platinum alloy wire having a cross-sectional diameter of
approximately 0.0005-0.005 inch, for example. The helical wire may
have other cross-sectional shapes and be formed of different
materials. Coil 26 is preferably sized so that when in its free
(uncompressed state) it extends the length of wire 34 with one end
adjacent the enlarged portion 36 at the proximal end of the wire
and the other end adjacent enlarged portion 38 at the distal end of
the wire. It is to be understood that the coil may not extend the
full length of the wire. For example, a flange or similar device
may be provided on an intermediate portion of wire 34 to limit
movement of the coil along the length of the wire.
[0065] When coil 26 is in its free state (with the wire in its
undeformed configuration), loops of the coil are generally spaced
from one another and do not exert any significant force on the wire
34 (FIGS. 3A and 3B). When the coil 26 is compressed (with the wire
34 in its deformed configuration), loops of the coil on the inner
portion 46 of the coil are squeezed together with a tight pitch so
that the loops are contiguous with one another while loops on the
outer portion 48 of the coil are spaced from one another (FIG. 3C).
This is due to the compressed inner arc length of coil 26 and the
expanded outer arc length of the coil. The compression of the loops
on the inner portion 46 of coil 26 exerts a force on the inner side
of wire 34 which forces the wire to spread open (i.e., tends to
straighten the wire from its closed configuration to its open
configuration). The end of coil 26 adjacent enlarged portion 36 is
held in a fixed position relative to wire 34. The opposite end of
coil 26 is free to move along wire 34 and is held in place when the
coil is in its compressed position by locking device 28. It should
be understood, however, that a coil (not shown) having sufficient
stiffness, for example, might be used where adjacent loops do not
contact one another when the coil is compressed to force wire 34
into an open position.
[0066] Referring to FIGS. 7A-7C, one embodiment of a releasable
locking device or release mechanism, which is disclosed in U.S.
patent application Ser. Nos. 09/089,884 and 09/090,305, is shown.
Releasable locking device 28a is adapted for releasably coupling a
fastener (such as any of the fasteners shown in FIGS. 3-6) to a
flexible member (such as flexible member 18, 18' or 18'') is shown
and generally designated with reference numeral 28a. Release
mechanism 28a comprises a flexible tubular member 50 having a
distal end portion 52 and is shown with tapered section or sleeve
2, which in turn is coupled to the flexible member. Tapered section
or sleeve 2, which provides a transition between the flexible
member and fastener for insertion of the fastener through tissue,
may be a separate member coupled to tubular member 50 or be formed
integrally therewith. Tubular member 50 further includes a proximal
end portion 54 releasably attached to wire 34. In this manner,
release mechanism 28a releasably couples the flexible member and
needle to the surgical fastener such as fastener 20. In addition to
releasably coupling the flexible member and needle to the fastener,
the locking device or release mechanism compresses coil 26 to bias
the fastener or surgical clip 20 in its open configuration,
facilitating insertion of the locking device 28 through tissue.
Although a straight tapered section is shown, it may be curved as
well. Tapered portion 2 may be formed from a metal alloy such as
stainless steel or a suitable polymeric material and may be solid
or in the form of a sleeve as noted above. Generally, tapered
section 2 gradually diminishes in diameter to provide a smooth,
non-stepped transition between the relatively small diameter of the
flexible member to the larger diameter of locking device such as
locking device 28a. The flexible member such as flexible member 18
may be swaged into the tapered section, or a heat shrink plastic
covering may hold the flexible member in place. The locking device
may also be curved.
[0067] Tubular member 50 is movable between a locked position
(FIGS. 7A and 7B) for holding coil 26 in its compressed position
and wire 34 in its deformed position, and an unlocked position
(FIG. 7C) for inserting or releasing the wire and coil. Referring
to FIGS. 7B and 7C, three slots 58 are shown formed in tubular
member 50 extending from the proximal end 54 of the member and
along at least a portion of the member. Slots 58 are provided to
allow the proximal end 54 of tubular member 50 to open for
insertion and removal of the wire 34. It is to be understood that
the number of slots 58 and configuration of the slots may vary, or
tubular member 50 may be formed to allow expansion of proximal end
54 without the use of slots.
[0068] Proximal end 54 of tubular member 50 includes a bore 62
having a diameter slightly greater than the outer diameter "d" of
wire 34, but smaller than the diameter of enlarged portion 38 at
the distal end of the wire and the outer diameter of the coil 26.
Bore 62 extends into a cavity 64 sized for receiving the enlarged
portion 38 of wire 34. Tubular member 50 may be described as having
an annular flange 61 for releasably securing enlarged portion 38.
As shown in FIG. 7C, upon application of an inwardly directed
radial squeezing force on the tubular member 50 proximal end 54 of
the tubular member is opened to allow for insertion or removal of
wire 34. When the force is released, the tubular member 50 moves
back to its locked position and securely holds wire 34 in place and
compresses the coil 26 as shown in FIG. 7A. A disc 51 may be
inserted into tubular member 50 to act as a fulcrum and cause the
proximal end 54 of the tubular member to open. Alternatively, disc
51 may be integrally formed with tubular member 50. As shown in
FIG. 7A, the length l of the bore 62 or flange 61 determines the
amount of compression of the coil, which in turn determines the
amount of deformation of wire 34. The greater the length l of bore
62, the greater the compression of coil 26 and the more
straightening of wire 34 will undergo. The compression of coil 26
is preferably limited so that wire 34 is not stressed beyond its
yield point. This allows wire 34 to revert back to its original
undeformed configuration and apply sufficient pressure to hold the
connected tissue together.
[0069] FIGS. 8A, 8B and 8C illustrate another release mechanism
which is generally designated with reference numeral 28b. FIGS. 8A
and 8B show the release mechanism in a locked position, and FIG. 8C
shows the release mechanism in an unlocked position. Release
mechanism 28b comprises a tubular member 80, which has proximal and
distal ends 88 and 89, respectively. Tubular member 80 further
includes bore 82 formed therein and a cavity or recess 84 extending
radially outward from bore 82 into the tubular member. Recess 84 is
configured to receive enlarged portion 38 or wire 34 as best
illustrated in FIG. 8A. Recess 84 and bore 82 form an annular
flange 86, which has an inner diameter less than that of enlarged
portion 38 and, thus, resists removal of the enlarged portion. In
the embodiment shown in FIG. 8A-C, three slots 87 are formed in
tubular member 80 as in the embodiment shown in FIGS. 7A-C. The
slots extend longitudinally from the proximal end 88 of tubular
member 80 and form fingers 81, which radially expand and release
wire 34 upon radial compression of the tubular member as shown in
FIG. 8C and as described above in connection with release mechanism
28a. In this embodiment, however, enlarged portion 38 forms a
fulcrum. Although three equiangularly spaced slots, which extend
parallel to the longitudinal axis are shown as in release mechanism
28a, the number and configuration of the slots may vary, or the
tubular member may be formed to allow expansion of the proximal end
portion without the use of slots. A tapered section 2 also may be
provided as described above in connection with release mechanism
28a.
[0070] FIGS. 9A-9E illustrate yet another release mechanism which
is disclosed in U.S. patent application Ser. No. 09/259,705, filed
on Mar. 1, 1999 and entitled Tissue Connector Apparatus With Cable
Release. The release mechanism is generally indicated with
reference numeral 28c in FIGS. 9A-9E where FIGS. 9A-C show the
mechanism coupled with a fastener, and FIGS. 9D and 9E show the
release mechanism depressed for release of the fastener. Locking
device or release mechanism 28c comprises a plurality of
substantially rigid strands, preferably wires 106, arranged
substantially parallel to one another and circularly about a
longitudinal axis of the aligned strands, to form a tube-like
configuration, as can be seen in the cross-sectional view of FIG.
9C and the perspective view in FIG. 9A. Alternatively, strands 106
may be cables or some other substantially rigid strand elements
arranged in the same manner as the wires shown in FIG. 9C. Upon
arrangement into the circular configuration, the hidden end
portions 106a of the strands are coupled to tapered section 2,
which is coupled to a piercing member or needle through a flexible
member such as flexible member 18.
[0071] Preferably, a rod 162 extends from tapered section 2 to
facilitate fixation of the strands thereto. The coupling of the
strands to tapered section 2 is preferably accomplished by gluing
or soldering to rod 162, although other equivalent or similar known
joining techniques may be employed (e.g. welding, threadably
attaching, etc). Similarly, rod 162 is preferably glued, soldered
or threaded into the needle or transition element. In an alternate
arrangement, the flexible member may extend through tapered section
2 and form a substitute structure for rod 162. This may be
preferred when the flexible member is a metal wire.
[0072] The end portions 106b of the strands in the vicinity of the
fastener strands include notches 109 which are formed into the
strands to a depth equal to approximately half the diameter of the
strand 106. When the strands are arranged in the circular
configuration described above, the notches 109 form a chamber 108
configured for receiving and holding enlarged portion 38. Although
enlarged portion 38 is shown as having a spherical shape, it may
have other shapes including a barrel shape, or other shape that may
be easily grasped and easily released. The notches are preferably
placed about 0.015'' from the free ends of the strands, but this
distance, of course, can be modified, depending upon the amount of
compression of spring 26 that is desired when ball 38 is inserted
into and held by notches 109.
[0073] After placement of ball 38 within chamber 108 formed by
notches 109, a shrink wrap layer, preferably a shrink tubing 110
may be provided over at least free end portions 106b of wires or
strands 106, and the tubing heated to compress against strands 106
and hold them in place against ball 38, preferably symmetrically
against ball 38. Together, tubing 110 and strands 106 effectively
hold ball 38 captive within notches 109. Alternatively, other
plastic or elastic restraining members may be mounted around the
distal portions of the wires or strands to aid in maintaining them
in place, preferably symmetrically against ball 38. Still further,
strand members may be designed with an elastic spring force
sufficient to maintain notches 109 in place with sufficient force
to maintain the bail 38 captive therein under the tensile forces
normally experienced during a suturing procedure. Although a
seven-strand embodiment is shown, it should be understood that
fewer or more than seven strands may be used. The number of strands
may vary depending on, for example, the size of the clip or the
size of the strands. Typically, the number of strands may range
from two to ten. In a coronary anastomosis, the number of strands
preferably will range from five to seven although other numbers may
be used.
[0074] In assembling, enlarged portion 38 of wire 34 is placed in
chamber 108. Tubing 110 is wrapped around at least a portion of the
strands (as shown in the drawings) and heated to maintain enlarged
portion 38 captive within the cavity formed by the strands.
Compression coil or spring 26 is slid over wire 34 and compressed
against portions 106b such that the fastener is in its open
configuration. Enlarged portion 36 may then be formed or attached
to wire 34 to maintain the fastener in its open configuration.
[0075] Release mechanism 28c is movable between a locked position
(FIGS. 9A-9c) and an unlocked position (FIGS. 9E and 9F). In the
locked position the ball 38 is held within notches 109 and
consequently, coil 26 is held in its compressed position, thereby
maintaining fastener wire 34 in its deformed or open position. In
the unlocked position, ball 38 is released from the notches,
thereby allowing the coil 26 to expand, which causes the fastener
wire 34 to close. The closure conformation of the wire may be
characterized by any of those described above with reference to
FIGS. 3-6, for example.
[0076] Movement of the release mechanism to the open position is
accomplished by applying a compressive force to the shrink tube 110
and bundle of strands 106, as shown in FIGS. 9D and 9E.
Advantageously, the compressive force may be applied at any
opposing locations around the circumference of the shrink tube as
long as the implement applying the force is oriented at an angle to
the strands, preferably substantially perpendicular thereto, to
allow the implement to traverse the strands so as to deform the
positions thereof when the force is applied. For example, needle
holder 111 could be rotated 90.degree. (or virtually any other
angle) with respect to the strands 106 as shown in the plane of the
drawing, while retaining the capability of deforming the strands to
an open position upon application of a compressive force. The
compressive force is preferably applied using a standard needle
holder 111 or forceps, although other tools could be used,
preferably those with applicators narrower than the length of the
shrink tube 110. As shown, the strands or wires 106 get distorted
from their circular configuration under the compression. This
change in shape stretches the shrink tube 110 from a circular
configuration to a somewhat elliptical configuration, and removes
some of the notches 109 from contact with ball 38, thereby
permitting removal of ball 38 from within the chamber previously
formed by notches 109 in the closed position.
[0077] Referring to FIG. 9F, release mechanism 23c also may be used
to releasably couple the other end of the fastener to another
flexible member such as flexible member 19, which in turn, is
coupled to a needle such as needle 17 as shown in FIG. 1. In this
arrangement, a member or stopper 115, which may be annular, is
secured to the other end of the fastener or wire 34 to prevent
enlarged portion 36 from passing through the compression spring
upon release from release mechanism 23c. Other release mechanisms,
which provide synchronized release of both needles illustrated in
FIG. 1, also can be used.
[0078] FIGS. 10A-10F illustrate synchronized fastener release
systems. Referring to FIGS. 10A-10C, a first synchronized release
system is shown in a coupled and decoupled state, respectfully.
Although one release mechanism is shown as corresponding to release
mechanism 28c, release mechanisms 28a or 28b or any release
mechanism which releasably couples the flexible member or needle to
the surgical fastener and effects compression of coil 26 also may
be used. At the other end of the fastener or wire 34, a release
mechanism that responds to the compressive state of coil 26 and
releases the fastener or wire 34 upon release of compressive forces
on the coil is shown and generally designated with reference
numeral 29a. Release mechanism 29a comprises two members 121 each
having a recess 122 formed therein and arranged to form chamber 124
when members 121 are aligned as shown in FIG. 10A. Recesses 122 are
configured to retain enlarged portion 36, which is shown with a
cylindrical configuration, but may have a spherical or other
suitable shape for operatively associating with a suitably
configured chamber. Further, members 121 may have semicircular
transverse cross sections or some other combination of transverse
shapes that can collectively provide the desired chamber to retain
enlarged portion 36. The number of members 121 also may vary as
would be apparent to one of ordinary skill.
[0079] Release mechanism members 121 have tapered ends 126, which
are configured for positioning between coil 26 and fastener wire 34
as shown in FIG. 10A. When tapered ends 126 are so positioned and
coil 26 is in a compressed state, coil 26 holds tapered ends 126,
which are normally biased away from each other as shown in FIG.
10C, sufficiently together to retain enlarged portion 36 within
chamber 124. When release mechanism 28c is actuated (e.g., radially
compressed) to release enlarged portion 38 of fastener wire 34,
coil 26 assumes its relaxed state, thereby releasing tapered ends
126 of release mechanism 29a from the coil and allowing the tapered
ends to radially expand and release enlarged portion 36 of fastener
wire 34 as shown in FIG. 10C. Accordingly, both needles and
flexible members may be decoupled from the fastener when release
mechanism 28c is actuated.
[0080] FIGS. 10D-10F show another synchronized fastener system that
is the same as the system shown in FIGS. 10A-10C with the exception
of release mechanism 29b and the cooperating portion of the
fastener or wire 34 being substituted for release mechanism 29a. In
this embodiment, an annular member or stopper 115, which may be
annular, is slidably coupled to fastener wire 34. Member 115 is
configured to resist passage of coil 26 thereover. Accordingly,
member 115 may have an outer diameter slightly greater than at
least the portion of the coil adjacent thereto. A tapered or
frustoconical member 3' is secured to an end of fastener wire 34,
which need not include an enlarged portion. Member 3' is the same
as member 3 with the exception that member 3' has a channel 134 for
receiving flexible member or suture 19. Channel 134 extends
radially outward from bore 132, which is formed through member 3',
for receiving the fastener or wire 34.
[0081] Flexible member 19 is threaded through channel 134 and
between tapered member 3' and annular member 115. When coil 26 is
in a compressed state as shown in FIG. 10D, the coil urges member
115 toward tapered member 3' and compresses flexible member 19
therebetween. In this manner, flexible member 19 is secured to the
fastener or wire 34. When release mechanism 28c is actuated (e.g.,
radially compressed) to release enlarged portion 38 of the fastener
or wire 34, coil 26 assumes its relaxed state so that annular
member 155 may slide away from tapered member 3' and release
flexible member 19. Accordingly, both needles and flexible members
may be removed from the fastener when release mechanism 28c is
actuated. Although a metal flexible member may be used, a polymeric
flexible member may be preferred.
[0082] FIGS. 11A and 11B show another release mechanism generally
indicated with reference numeral 29c. Release mechanism 29c
includes a sleeve 142, which is slidably mounted over flexible
member 19 so that it can be positioned over the flexible member and
the fastener or wire to releasably hold the flexible member and the
fastener together. The end portion of the flexible member opposite
the needle and the end portion of the fastener or wire to be
engaged therewith may be configured to provide interlocking
engagement therebetween. In the embodiment shown in FIGS. 11A and
11B, the flexible member, which preferably is metal in this
example, and the fastener or wire end portions have mating flange
and groove configurations. Flexible member 19 includes groove 144a
and flange 146a, which mate with or interlockingly engage groove
144b and flange 146b, which are formed in wire 34. When sleeve 142
is moved away from the fastener or wire, the coupling becomes
unrestrained and the flexible member and the fastener or wire can
be readily separated by removing flanges 146a and 146b from grooves
144a and 144b as shown in FIG. 11B. Member 115 may be secured to
fastener wire 34 to prevent the end of coil 26 adjacent to groove
144b and flange 146b from sliding thereover. Member 115 also may be
described as a stopper for spring 26.
[0083] FIGS. 12A and 1213 show another release mechanism, which is
generally designated with reference numeral 29d. In this
embodiment, tapered member 3 is provided with a bore for receiving
both flexible member 19 and the fastener or wire 34. Member or
collar 115 may be fixedly secured to the fastener or wire 34 to
resist coil movement over the wire and toward the flexible member.
The fastener or wire also may be fixedly secured to the inner wall
of tapered member 3 by, for example, gluing or welding. One end of
the flexible member is tied into a knot such as knot 150. The knot
is packed into the bore 152 and the tapered member is swaged or
crimped as shown in FIGS. 12A and 12B to secure the knot in the
bore. The flexible member is cut as shown in FIG. 12B to decouple
the flexible member from the fastener.
[0084] FIGS. 13A and 13B illustrate a further release mechanism,
which is generally designated with reference numeral 29e. Release
mechanism 29e generally comprises a release member having a cavity
formed therein to receive the fastener or wire 34 and a portion
configured for severing the fastener wire. This advantageously
eliminates the need for a separate cutting tool to separate the
suture or needle from the fastener. One example of such a release
member is shown as release member 160. Release member 160 has one
end that is fixedly secured to tapered member 3 to which flexible
member 19 is secured. Alternatively, members 3 and 160 may be
integrally formed. Release member 160 is configured to form a
cavity 162 therein and may be in the form of a sleeve. Member 160
includes annular flange 164 through which fastener wire 34 is
received. Annular flange 164 includes an annular lip 166, which
forms a cutting surface or annular blade. Release member 160 also
may include an opening for receiving flexible member 19
therethrough as shown in FIGS. 13A and 13B. In this example,
release member 160 can be fixedly secured to flexible member 19,
which, in turn, can be fixedly secured to tapered member 3. Of
course, it should be understood that members 160 and 3 can be
directly secured to one another or integrally formed as a single
piece. When release member 160 is radially compressed as shown in
FIG. 13B, annular lip severs fastener wire 34 and decouples
flexible member therefrom. Fastener wire 34 may be provided with
annular groove 168 to enhance wire fracture. Release member 160 or
annular lip 166 may be 400 series stainless steel or tool steel to
facilitate hardening. Other materials that tend to provide an
effective cutting tool also may be used. Release member 160,
however, should comprise material that provides the desired
flexibility. Further, it should be understood that although release
member 160 is shown with a generally cylindrical configuration,
other configurations may be used. In assembly, member 115, which
may be annular, may be swaged, glued or welded to wire 34 to
compress coil 34 after the other end of wire has been secured to a
locking device or coupling so that the fastener opens as may be
done in the embodiments of FIGS. 11A and B and 12A and B. Wire 34
may be preformed with groove 168 or the groove formed prior to
sliding member 160 over wire 34 so as to engage blade 166 with the
groove.
[0085] It is to be understood that locking devices other than those
described above may be used without departing from the scope of the
invention. For example, a locking device (not shown) may comprise a
tubular member having an opening formed in a sidewall thereof for
receiving an end portion of the wire. The end of the wire may be
bent so that it is biased to fit within the opening in the sidewall
of the tubular member. An instrument, such as a needle holder may
then be used to push the wire away from the opening in the tubular
member and release the wire from the tubular member. Various other
types of locking devices including a spring detent or bayonet type
of device may also be used. Further, the fastener or wire end
portions may be configured differently than that shown. For
example, one or both of the fastener or wire end portions may be
provided with grooves instead of enlarged portions and the release
mechanisms or locking device arms, such as, for example, fingers 81
or strands 106, may be provided with projections to releasably
engage with the grooves.
[0086] FIG. 14A is a front view of another embodiment of a tissue
connector assembly of the present invention which is generally
designated with reference numeral 211. Tissue connector assembly
211 is the same as tissue connector assembly 11 with the exception
that locking device or release mechanism 28 is directly connected
to needle 16. Although any of the release mechanisms 28a-c may be
used to couple the fastener to needle 16; release mechanism 28c is
shown in FIG. 14B for purposes of illustrating a connection between
a locking device and needle 16.
[0087] Referring to FIG. 14B, rod 162 extends from needle 16. Rod
162 and needle 16 may be integrally formed or be separate elements
secured which are fixed to one another. The coupling of strands 106
to the needle is preferably accomplished by gluing or soldering to
the rod 162, although other equivalent or similar known joining
techniques may be employed (e.g. welding, threadably attaching,
etc). Similarly, when the rod and needle are discrete elements, the
rod is preferably glued, soldered or threaded into the needle.
Alternately, rod 162 may extend from or be affixed to a transition
element that in turn is affixed to needle 16.
[0088] FIG. 15 is a front view of a lateral tissue connector which
is generally designated with reference numeral 300 and which can be
used in conjunction with any of the assemblies described above as
will be described in detail below. Tissue connector assembly 300
generally includes needle 16, a locking device or release
mechanism, and a fastener, which may be fastener 20, 40, 41, or 43,
for example. In this embodiment, needle 16 is attached directly to
a locking device, such as locking device 28c, a connection for
which is described above with reference to FIG. 14A. FIG. 14A shows
tissue connector assembly 211 with the fastener in its open
(deformed) configuration.
[0089] FIG. 17 is a front view of a bridge clip embodiment of a
tissue connector assembly of the present invention, generally
designated with reference numeral 1701. Tissue connector assembly
1701 includes a bridge clip 1707 having a pair of clips or
fasteners 1703 and a connecting bridge 1705. Each of the pair of
clip and components corresponding to each of the pair of clips is
denoted with a prime or double-prime. Thus, for example, the pair
of clips includes a first clip 1703' and a second clip 1703''. In
one embodiment, the materials and configuration of tissue connector
assembly 1701 are essentially symmetric, and corresponding primed
and double-primed components are mirror images of one another. In
another embodiment, tissue connector assembly is not symmetric, and
thus a primed component and the corresponding double-primed
component may be of different materials or geometry, or may be
constructed differently but be functionally equivalent.
[0090] Each one of clips 1703 includes wire 34 surrounded by a
corresponding coil 26, that can provide a bias force to keep each
clip in an open configuration. Clips 1703 may be fastener 20, 40,
41, 43, or other similar fasteners. The end portion of each coil 26
near bridge 1705 is restrained by a corresponding stopper 115
attached to wire 34, while the opposite end of the coil can be
restrained by a corresponding release mechanism 28. As with the
embodiment of FIG. 1, the free ends of fasteners 1703 are
releasably coupled through the release mechanisms 28 to flexible
members 18, and to piercing members 16, respectively. The two clips
1703 are thus seen to act as two clips similar to fastener 20 of
FIG. 1, joined together near their respective stoppers 115. In the
preferred embodiment, wires 34' and 34'' are two sections of a
single wire 34 that is made of a shape memory alloy that has be
heat treated to form the double-loop configuration described
herein. The bridge clip 1707 can be assembled by heat treating wire
34 to the closed configuration, as describe previously, threading
stoppers 115 followed by coils 36 over wires 34, mounting the
release mechanisms 28, moving stoppers 115' and 115'' apart to
produce the required biasing force on the wire, and then crimp,
swage or weld the stoppers to the wire. An assembly 1701 thus
assembled will maintain the configuration of FIG. 17 until the
biasing force of one of coils 26 is released.
[0091] For a symmetric tissue connector assembly 1701 embodiment
noted in the previous embodiment, each of clips 1703 are
constructed of the same materials, with clip 1703' and clip 1703''
being mirror images. Examples of tissue connector assembly 1701
that is not symmetric, include, but are not limited to having clips
1703' and 1703'' of different sizes or shapes, having coils 26' and
26'' produce different biasing forces, or having flexible members
18 of different lengths, sizes or materials.
[0092] FIG. 18 shows the configuration of the bridge clip 1707 of
FIG. 17 after actuation of release mechanisms 28. Upon release of
release mechanisms 28, coils 26 move towards enlarged portions 36,
reducing the biasing force and allowing clips 1703 to move towards
the closed configuration, as shown. Thus in addition to causing the
release of bridge clip 1707 from flexible members 18, actuation of
release mechanisms 28 also triggers a self-closing action causing
the clip to transition from the open configuration of FIG. 17
towards the closed configuration of FIG. 18. The separation and
orientation of clips 1703' and 1703'' are fixed by the heat-treated
configuration of the wire. Thus in one use, bridge clip 1707 can be
used to secure tissue at two positions (through the loops of clips
1703' and 1703'') that are accurately determined by the separation
provided by bridge 1705.
[0093] As an alternative embodiment, coils 26' and 26'' can be
replaced with one coil (not shown) that is coupled to both release
mechanisms 28, and which supplies a biasing force to keep both of
clips 1703 biased in an open position. Release of either of either
of release mechanisms 28' or 28'' partially releases the biasing
force, causing both clips 1703 to return to a partially closed
position. Release of the other of release mechanism 28 decreases
the biasing force to allow both of clips 1703 to return to a fully
closed position. There are many alternative embodiments for the
various components of tissue connector assembly 1701. Thus for
example, flexible members 18 can be constructed as shown in one of
FIG. 2A or 2B or other structures as described previously.
Additionally, the discussion of release mechanisms described in
reference to FIGS. 7 through 11 can also be applied, separately or
in combination to the two release mechanisms 28 of tissue connector
assembly 1701.
[0094] The shape of bridge clip 1707 when released from flexible
members 18 is shown in FIG. 18. With release mechanisms 28 of FIG.
17 released, both self-closing fasteners 1703 become unbiased and
assume the closed configurations of FIG. 18. In the closed
configuration the bridge 1705 is clearly seen to be a nearly
straight portion that is formed between the two closed clips 1703.
In a specific embodiment, fasteners 1703 are formed of a memory
shape alloy. By forming the clip material in the shape shown in
FIG. 18, the two fasteners 1703 are connected by a fairly rigid
bridge portion 1705. One particularly useful embodiment orients
loop of clips 1703 at right angles to bridge 1705. It can be seen
in the figure, and by subsequent descriptions, that the closed
fastener of FIG. 18 can be used to hold tissue at two positions
(one at by each clip loop) separated by the distance of the bridge
1705. The bridge clip 1707 thus can be used to secure tissue at two
locations with the loops of fasteners 1703, with the locations
supported by the bridge 1705. Bridge clip 1.707 can thus be used to
hold tissues together at two separate locations, or by application
of pressure by bridge 1705 onto fasteners 1703, pressure may be
applied along the length of the bridge clip. Specific uses of
bridge clip 1707 include, but are not limited to, providing
anchoring of the fastener against the tissue, and as such are
useful in many of the attachment procedures described previously,
and attaching tissues as for example, as a type of horizontal
mattress suture.
[0095] As noted above, tissue connector assemblies described above
have many uses. They may be especially useful for minimally
invasive surgical procedures including creating an anastomosis
between a vascular graft 12 and an artery 14. The anastomosis may
be used to replace or bypass a diseased, occluded or injured
artery. A coronary bypass graft procedure requires that a source of
arterial blood flow be prepared for subsequent bypass connection to
a diseased artery. An arterial graft may be used to provide a
source of blood flow, or a free graft may be used and connected at
the proximal end to a source of blood flow. Preferably, the source
of blood flow is one of any number of existing arteries that may be
dissected in preparation for the bypass graft procedure. In many
instances it is preferred to use the left internal mammary artery
(LIMA) or the right internal mammary artery (RIMA), for example.
Other vessels which may be used include the saphenous vein,
gastroepiploic artery in the abdomen, radial artery, and other
arteries harvested from the patient's body as well as synthetic
graft materials, such as DACRON.RTM. (polyester fibers) or
GORETEX.RTM. (expanded polytetrafluoroethylene). If a free graft
vessel is used, the upstream end of the dissected vessel, which is
the arterial blood source, will be secured to the aorta to provide
the desired bypass blood flow, as is well known by those skilled in
the art. The downstream end of the graft vessel is trimmed for
attachment to an artery, such as the left anterior descending
coronary (LAD). It is to be understood that the anastomosis may be
formed in other vessels or tissue.
[0096] FIGS. 16A-16D diagrammatically illustrate a method of
aligning and connecting graft and target vessels, such as
connecting a graft vessel 12 to an artery 14 (target vessel) using
tissue connector assemblies 11 and 300. In this example, two tissue
connector assemblies 11 are used to make connections at generally
opposite sides of the graft vessel and tissue connector assemblies
300 are used to make connections between those made with assemblies
11. The procedure may be accomplished with a beating heart
procedure with the use of a heart stabilizer to keep the heart
stable, for example. The procedure may also be performed
endoscopically. It also should be understood that tissue connector
assemblies 211 may be substituted for assemblies 11.
[0097] The patient is first prepped for standard cardiac surgery.
After exposure and control of artery 14, occlusion and reperfusion
may be performed as required, an arteriotomy is performed on artery
14 to provide an opening 120 for receiving a graft vessel. After
the snared graft vessel 12 has been prepared as would be apparent
to one of ordinary skill in the art, a tissue connector assembly 11
is attached to the free end of the graft vessel along an edge
margin of the vessel. In order to attach the connector assembly 11,
the surgeon grasps needle 16 with a needle holder (e.g., surgical
pliers, forceps, or any other suitable instrument) and inserts
needle 16 into the tissue of graft vessel 12 in a direction from
the interior of the vessel to the exterior of the vessel. The
surgeon then releases the needle 16 and grasps a forward end of the
needle which is now located outside graft vessel 12 and pulls the
needle and a portion of suture 18 through the vessel. Needle 17 is
passed through opening 120 formed in the sidewall of the artery 14
and inserted into the tissue of the artery in a direction from the
interior of the artery to the exterior of the artery. The surgeon
then grasps needle 17 located outside the artery 14 and pulls the
needle and a portion of suture 19 through the arterial wall. A
second tissue connector assembly 11 may be inserted as described
above at a location generally 180 degrees from the location of the
first tissue connector in a conventional "heel and toe"
arrangement.
[0098] Once the tissue connector assemblies 11 are inserted, graft
vessel 12 is positioned above and aligned with opening 120 in the
sidewall of the artery 14 (FIG. 16A). A section of each assembly is
located between graft vessel 12 and artery 14. The needles 16 and
17 arc pulled generally away from the artery 14 to reduce the
length of the sutures 18 and 19 (eliminate slack of the sutures)
between vessel 12 and artery and "parachute" the vessel onto the
artery (FIG. 16B). The needles 17 are then pulled away from the
artery 14 until each fastener 20 is positioned within the target
vessel 14 as shown in FIG. 16B. Needles 16 are then pulled away
from graft 12 until the fasteners are positioned with one end of
each fastener 20 extending from the vessel and the opposite end of
each fastener extending from the artery (FIG. 16C). The edges of
the graft vessel 12 and artery 14 are positioned adjacent one
another to form a continuous interior and exterior surface along
the mating portions of the vessel and artery. As shown in FIG. 16F,
the tissue is compressed within the fastener 20.
[0099] A surgical instrument (e.g., needle holder) is used to
radially squeeze each locking device 28 to release the locking
device from the fastener 20. Upon removal of each locking device
28, each coil 26 moves to its free uncompressed state which allows
fastener wire 34 to return to its original undeformed closed
position (FIG. 16D). As the wires 34 move to their closed position
the adjacent tissues of the graft vessel 12 and artery 14 which
were previously pulled together during the parachuting of the graft
vessel onto the artery, are squeezed together to securely engage
the graft vessel and artery (FIGS. 16E and 16F). It should be noted
that as each locking device 28 is squeezed at least two steps are
accomplished. The fastener 20 is released from locking device 28,
thus allowing coil 26 to uncompress and the wire 34 to move to its
closed configuration, and the needle 16 is released from the
fastener. Thus, any of the locking devices 28 described above
provides for simultaneous actuating closure of the fastener 20 and
release of the needle 16 from the fastener. Further, radially
compression of release mechanisms 29 releases needles 17 and
sutures 19 from the fasteners. However, if one of the synchronous
release systems described with reference to FIGS. 10A-10F is used,
radial compression of a locking device 28 device will effect
essentially simultaneous closure actuation of a respective fastener
and release of needles 16 and 17 and sutures 18 and 19.
[0100] The tissue connector assemblies 300 arc subsequently
inserted at circumferentially spaced locations around the periphery
of the graft vessel to sealingly fasten graft vessel 12 to artery
14. Needle 16 of fastener 300 is inserted into graft vessel 12 from
the exterior surface of the graft vessel and pushed through the
graft vessel and artery 14 tissue. The needle holder is then used
to pull the needle 16 through the arterial wall. An instrument
(same needle holder or other suitable instrument) is used to apply
a squeezing force to the locking device 28 to release fastener 20
from needle 16. This allows coil 26 to move to its uncompressed
configuration and the wire to move to its closed position. It
should be noted that the tissue connector assemblies 11 may remain
with their fasteners in their open position while tissue connector
assemblies 300 are inserted into the tissue and moved to their
closed position. The locking devices 28 of the tissue connector
assemblies 11 may subsequently be removed from the fasteners 20 to
allow the fasteners to move to their closed position. The number
and combination of tissue connector assemblies 11 and 300 required
to sealingly secure the connecting tissues together may vary. For
example, only tissue connector assemblies 11 may be used to
complete the entire anastomosis.
[0101] Although coils 26 are shown remaining on the fastener or
wire (FIG. 16D), it is to be understood that coils 26 may also be
removed from wires 34, leaving only the wires in the connected
tissue.
[0102] As an alternative to inserting tissue connector assemblies.
11 at "heel and toe" locations described above, a number of tissue
connector assemblies 11 may be inserted generally around the
location of the heel. The graft vessel may then be pulled towards
the artery to determine whether the opening formed in the sidewall
of the artery is large enough before completing the anastomosis. It
also should be understood that tissue connector assemblies 211 may
be used instead of or in conjunction with assemblies 11.
[0103] FIGS. 19A-19D diagrammatically illustrate an alternative
method of aligning and connecting graft and target vessels, such as
connecting a graft vessel 1901 to an artery 1903 (target vessel)
using tissue connector assemblies 1701 and 1907. The bridge clip of
tissue connector assembly 1701 can be used to secure the
anastomosis at the heal or at the toe, while tissue connector
assembly 1907 can be a tissue connector assembly attached to one
piercing member, as disclosed in the copending U.S. patent
application having Ser. No. 09/259,705. Alternatively tissue
connector 300 could be used in place of tissue connector 1907. In
this example, one tissue connector assembly 1701 is used to make a
connection where a toe 1905 of graft vessel 1901 attaches to target
vessel 1903, and other tissue connectors 1907 are used at the other
attachment locations.
[0104] FIG. 19A shows tissue connector 1905 after threading each of
piercing members 16' and 16'' through the outer surface of toe 1905
and through the inner surface of target vessel 1903. Piercing toe
1905 at two points having the approximate spacing of the length of
bridge 1705 allows the bridge to be brought against the outer
surface of the graft vessel 1901. This positioning, in which one
vessel is brought down or "parachuted" onto another, is
advantageous for performing an anastomosis, as it allows the graft
vessel to be pulled down onto the target vessel 1903. Because the
bridge is rigid, the force on target vessel 1903 is distributed
across the bridge 1705. In contrast, the use of a flexible suture
for this procedure would pull the tissue between the two piercings
together producing a "purse string" effect that is not desired when
suturing, and could also possibly tear the tissue.
[0105] The piercings on target vessel 1903 are spaced similarly to
those on toe 1905. With tissue connector 1701 positioned as in FIG.
19A, the piercing members 16' and 16'' can be gently pulled,
allowing for precise and careful placement of toe 1905 on target
vessel 1903. Once the vessels 1901 and 1903 are aligned and the
release members 28 and 29 are pulled through the top side of target
vessel 1903, bridge clip 1707 can be released from the flexible
members 18 and piercing members 16. FIG. 19B shows bridge clip 1707
in the closed configuration as it appears after joining vessels
1901 and 1903. Each fastener 1703a and 1703b is positioned, prior
to closing, from the outer to inner surface of graft vessel 1901
and through the inner to outer surface of target vessel 1903. Upon
closing, each fastener completes the loop, holding the two vessels
at two positions separated by the distance of the bridge 1705. The
fastening of the vessels at two locations that are held together by
the bridge portion provides added support to the anastomosis at the
point where the forces which tend to pull the vessels apart is
greatest. Once the graft-target attachment is secured at toe 1905
the remainder of the attachment can be performed using tissue
connectors 1907 as shown in FIGS. 19B-C.
[0106] Although the suturing procedure has been described for an
end-to-side anastomosis, it should be appreciated that the
procedure is applicable to an end-to-end and side-to-side
anastomosis, connecting various tissue structures including single
and multiple tissue structures, and puncture sites, and connecting
tissue to a prosthetic graft or valve, for example.
[0107] Bridge clip 1705 can also be used to perform an attachment
similar to a horizontal mattress suture, as is illustrated in FIG.
20. FIG. 20A and 20B show a top and a side view, respectively, of
bridge clip 1705 used to perform a horizontal mattress suture. A
procedure that may be used to clip the tissue as in FIG. 20 is to
aligning tissue edges 2007 and 2009 of tissues 2001 and 2003,
pierce tissue 2001 and 2003 with piercing members 16 to create
piercings 2005, and then releasing clips 1703. When this is done,
the bridge portion 1705 sits on an outer surface to tissue 2001
while the clips 1703 go through the piercings 2005 and wrap around
the edges 2007 and 2009 to towards tissue 2001.
[0108] It will be observed from the foregoing that the tissue
connector assemblies of the present invention have numerous
advantages. Importantly, the assemblies are easier and faster to
apply than conventional sutures that require tying multiple knots.
The assemblies also may be used in minimally invasive procedures
including endoscopic procedures.
[0109] All references cited above are incorporated herein by
reference.
[0110] The above is a detailed description of particular
embodiments of the invention. It is recognized that departures from
the disclosed embodiments may be made within the scope of the
invention and that obvious modifications will occur to a person
skilled in the art. The full scope of the invention is set out in
the claims that follow and their equivalents. Accordingly, the
claims and specification should not be construed to unduly narrow
the full scope of protection to which the invention is
entitled.
* * * * *