Note: Descriptions are shown in the official language in which they were submitted.
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SINGLE-TAILED SUTURING METHOD AND APPARATUS
Eacksround of the Invention
This invention relates generally to the creation of a sliding and locking loop
of cord, and more particularly to a surgical technique of suturing and the
formation
of a suture loop that may be tightened and locked.
Suturing is a necessary aspect of virtually any surgical procedure.
Numerous techniques of tying sutures have been developed by surgeons over the
years to address various applications of sutures. For example, a surgeon's
knot, in
which an overhand knot is modified to include two wraps of the suture ends
around
each other, was developed to minimize the amount of slippage in the suture as
the
second or locking throw of a ligation or approximation of tissue was
accomplished.
I0 Another knot called a Roeder knot was developed to allow surgeons to place
a loop
of suture axound a vessel for ligation in an endoscopic environment. The
Roeder
knot is basically a pre-tied slip knot that may be cinched and locked around a
vessel
or other structure. Many other knots, such as the Weston knot described in
U.S.
Patent No. 5,405,352 address various other aspects of the surgical
requirements of
knots for flexibility, development of hoop stress (tightening of the suture
loop),
stability and reversibility.
In some cases, the development of a knot in a surgical procedure may
require dexterity beyond the capability of the surgeon. This is certainly the
case in
surgeries such as arthroscopic, laparascopic, or thoroscopic surgery. These
procedures are accomplished with the aid of an endoscope, a viewing instrument
that can be used in conjunction with specialized surgical instnunentation to
detect,
diagnose, and repair areas of the body that were previously only able to be
repaired
using traditional "open" surgery. Access to the operative site using
endosurgical or
minimally invasive techniques is accomplished by inserting small tubes called
trocars into a body cavity. These tubes have a diameter of, for example,
between
3mm and 30mm and a length of about 150mm (6 inches). A commonality in these
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2
procedures is that the spaces in which the surgeon worles are limited, and the
tools
used for suturing make tying lcnots difficult at best. Surgeons are accustomed
to
handling the suture, as l~nots in open procedures are typically tied and
pushed down
to the wound using the fingers. In endoscopic procedures, either the lrnots
need to
be tied externally to the body and inserted into the body and to the operative
site
using some kind of knot pushing device, or they need to be tied inside the
body
using long, clumsy instruments.
Currently, in one known technique, the placement of sutures while.using
endoscopic techniques involves placing a semi-circular needle, attached to and
carrying a suture, into a pair of endoscopic needle holders. These needle
holders,
which resemble a pair of pliers with an elongated shaft between the handles
and the
jaws, must be placed down through one of the surgical trocars into the body
cavity
containing the structure to be sutured. Because of their size, the needles
used in
these procedures are generally not able to be held in the jaws of the needle
driver
while being introduced through the operative trocar. The surgeon must hold the
suture string in the needle holder jaws, and push the needle holder trailing
the
needle and suture into the body cavity. The suture and needle combination is
dropped in the body cavity, and the needle is then located and picl~ed up and
properly positioned in the needle holder jaws. This is a difficult and time-
consuming aspect of this current endoscopic technique for suturing. The needle
carrying the suture may then be driven by pronation of the wrist, causing
rotation of
the elongate shaft, and subsequent arcuate rotation of the semi-circular
needle.
The current instrumentation requires the surgeon to prepare the needle for
penetration of the tissue while the needle is inside the body. This process is
a time
consuming, and sometimes frustrating exercise in hand to eye coordination,
which
is complicated by the fact that the surgeon is viewing the three dimensional
space
inside the body cavity through a two dimensional video monitor.
There have been other attempts to improve the methods of tissue repair.
These include the development of staplers and anchoring devices. In response
to
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some of the aforementioned problems in placing sutures in tissues
endoscopically,
manufacturers have developed tissue staplers. These devices utilize stainless
steel
or titanium staples that are constructed much like the staples used to hold
papers
together. The major disadvantage of these kinds of staplers is that they leave
metal
in the body. For some tissues this is not a problem, however in some
procedures,
metal staples left within the tissues can be a major hindrance to the healing
process.
In orthopedic surgery, many different designs for bone anchors have been
developed. These anchors allow soft tissues to be reattached to bone, and
simplify
the process by removing the need to create a transosseous tunnel. Transosseous
tunnels are created in bones to allow suture material to be threaded through
and tied
across the bony bridge created by tunnels after the suture material has been
placed
through the soft tissues and tied with conventional knots. Anchors are
commonly
used in joint re-constructions, and because the metal is contained in the
bone, it
does not cause a problem with healing.
While endoscopy has certainly found favor with many physicians as an
alternative operative modality, the advanced skill set and operative time
necessary
to become an efficient and practiced endoscopist have proven to be a challenge
for
a large portion of the surgical community. The cost pressures brought about by
large scale patient management (the continued rise and success of health
maintenance organizations or HMO's) have also caused the surgical community to
cast a critical eye on the overall costs and long-term outcomes of some of the
procedures that have been tried via a endoscopic approach. While the
laparascopic
cholecystectomy (gall bladder removal) has certainly proven its worth in the
past 8-
10 years, many other procedures have not shown similar cost effectiveness and
positive long-term outcomes.
Hence, alternatives have been sought to bridge the gap between skill and
equipment intensive endoscopic surgery and more familiar open surgery. As
such,
under the broad umbrella of "minimally invasive surgery" which would include
endoscopic surgery, a relatively new approach called "mini-incision surgery"
has
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begun to emerge. This approach uses the principles of traditional open
surgery,
along with some of the equipment advances of endoscopy to provide the patient
with the best of both worlds.
Perhaps the most visible of these new approaches is the emergence of
minimally invasive heart surgery, both for coronary bypass and fox valve
replacement. Techniques and tools for cardiovascular surgery have begun to be
used that allow the heart surgeon to perform procedures through small
incisions
between the ribs that previously required a massive incision and splitting the
sternum to gain access to the heart.
In a similar way, orthopedic surgeons have begun to explore alternatives to
the traditional open approach for the many indications requiring
reconstruction of
some aspect of the shoulder. As was the case when minimally invasive
approaches
were adopted for knee repair and re-construction, the use of either an
endoscope or
a "mini-open" approach is gaining in popularity with surgeons, patients and
third
party payers.
It is an increasingly common problem for tendons and other soft, connective
tissues to tear or to detach from associated bone. One such type of tear or
detachment is a "rotator cuff' tear, wherein the supraspinatus tendon
separates from
the humerus, causing pain and loss of ability to elevate and externally rotate
the
arm. Complete separation can occur if the shoulder is subjected to gross
trauma,
but typically, the tear begins as a small lesion, especially in older
patients.
To repair a torn rotator cuff, the typical course today is to do so
surgically,
through a large incision. This approach is presently taken in almost 99% of
rotator
cuff repair cases. There are two types of open surgical approaches for repair
of the
rotator cuff, one known as the "classic open" and the other as the "mini-
open". The
"classic open" approach requires a large incision and complete detachment of
the
deltoid muscle from the acromion to facilitate exposure. Following the
suturing of
the rotator cuff to the humeral head, the detached deltoid is surgically
reattached.
Because of this maneuver, the deltoid requires postoperative protection, thus
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retarding rehabilitation and possibly resulting in residual weakness. Complete
rehabilitation takes approximately 9 to 12 months.
The "mini-open" technique, which represents the current growing trend and
the majority of all surgical repair procedures, differs from the classic
approach by
5 gaining access through a smaller incision and splitting rather than
detaching the
deltoid. Additionally, this procedure is typically used in conjunction with
arthroscopic acromial decompression. Once the deltoid is split, it is
retracted to
expose the rotator cuff tear. The cuff is debrided to ensure suture attachment
to
viable tissue and to create a reasonable edge approximation. In addition, the
humeral head is abraded or notched at the proposed "soft tissue to bone"
reattachment point, as healing is enhanced on a raw bone surface. A series of
small
diameter holes, referred to as transosseous tunnels, are "punched" through the
bone
laterally from the abraded or notched surface to a point on the outside
surface of the
greater tuberosity, commonly a distance of 2 to 3 cm. Finally, the cuff is
sutured
and secured to the bone by pulling the suture ends through the transosseous
tunnels
and tying them together using the bone between two successive tunnels as a
bridge,
after which the deltoid muscle must be surgically reattached to the acromion.
Although the above described surgical technique is the current standard of
care for rotator cuff repair, it is associated with a great deal of patient
discomfort
and a lengthy recovery time, ranging from at least four months to one year or
more.
It is the above described manipulation of the deltoid muscle together with the
large
skin incision that causes the majority of patient discomfort and an increased
recovery time.
Less invasive arthroscopic techniques are beginning to be developed in an
effort to address the shortcomings of open surgical repair. Working through
small
trocar portals that minimize disruption of the deltoid muscle, a few surgeons
have
been able to reattach the rotator cuff using various bone anchor and suture
configurations. The rotator cuff is sutured intracorporeally and an anchor is
driven
into bone at a location appropriate for repair. Rather than thread the suture
through
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6
transosseous tunnels which are difficult or impossible to create
arthroscopically
using current techniques, the repair is completed by tying the cuff down
against
bone using the anchor and suture. Early results of less invasive techniques
are
encouraging, with a substantial reduction in both patient recovery time and
discomfort.
However, as will now be described, there are cases where the knots
themselves are a hindrance to the healing of the wound. In cases where joint
re-
constructions are undertaken by orthopedic surgeons, oftentimes the space
available
within joint is quite limited. This is especially true, for example, in a
rotator cuff
repair. The knots in the tendon can be bulky and create a painful impingement
of
the tendon on the bone. Because non-absorbable suture materials are used for
these
types of repairs, the suture and associated knots are not absorbed into the
body, and
hence provide a constant, painful reminder of their presence. It would
therefore be
desirable to develop a system that did not require the traditional knots to
secure the
suture to the tendon.
So it may be seen that none of the currently extant approaches to the
placement and securing of sutures in, for example, rotator cuff surgery have
fulfilled all of the surgeon's requirements.
What is needed, therefore, is a new approach for repairing the rotator cuff,
wherein suture tension can be measured and adjusted, the suture resides
completely
below the cortical bone surface, there is no requirement for the surgeon to
tie a knot
to attach the suture to the bone anchor, and the skill level for correct
placement is
suitable for practitioners having average ability.
Summar;~f the Invention
Accordingly, the inventors have developed a novel system and method for
creating a suture loop and securing the suture material to tissue. This is
done by
taking advantage of some of the unique aspects of the construction of braided
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sutures. These sutures, commonly constructed out of sills, cotton, or
polyester
fibers, are woven into an 8 to 10 ply hollow diamond braid. Oftentimes, one or
two
core fibers are run down the middle of the diamond braid. In the present
invention,
these core fibers are eliminated. They may be replaced by pull loops, which
will be
more fully explained below.
The hollow nature of the diamond braid allows for the formation of a unique
"single-tailed" suture. This suture is formed by taking one end of the suture
(the
free end) and passing it through an opening formed in the diamond braid and
into
the hollow interior lumen of the other half of the suture (the standing part).
Much
like the familiar children's toy which is commonly identified as a "Chinese
finger
torture", the diamond braid, by the very nature of its configuration, is able
to
expand and contract in diameter based on the forces exerted on the fibers.
When
the suture or hollow core cord is placed in compression, the fibers allow for
the
expansion of the diameter, both exteriorly and in the hollow inner lumen. When
tension is placed on the suture, the fibers are allowed to contract, and, in
the case of
the single tailed suture, the free end that has been passed into the interior
Iumen of
the standing end is compressed and held by the contraction of the diameter of
the
standing part.
There are many different methods and tools that can be used to create the
single tail loop. In the present invention, various configurations of fads,
pull
strings, and other tools may be used to thread the free end of the suture
through the
interior lumen of the standing end of the suture. A fid is a tool that allows
the free
end to be threaded through the standing end by parting the fibers of the
hollow cord
wall. A fid is typically a hollow, tapered cylinder with a smoothly closed end
and
an open end that is disposed to receive the free end of the hollow cord. It
has an
outside diameter minimally greater than the outside diameter of the cord.
More particularly, there is provided a suture having a structure which
comprises a plurality of flexible filaments loosely woven together in a
tubular
geometry. The desired tubular geometry includes an outer wall which defines an
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internal lumen. The construction is such that when a first portion of the
suture is
placed under compression, the outer wall of the first portion is radially
expanded,
such that a diameter of the first portion internal lumen increases in size
sufficiently
so that a second portion of the suture structure, which is not under
compression,
may be accommodated within the first portion lumen. However, when the suture
first portion is subsequently placed under tension, while the suture second
portion
is disposed within the first portion lumen, the diameter of the first portion
lumen
decreases sufficiently to capture the suture second portion therein to create
a
binding interface between the first and second suture portions, thereby
locking the
second suture portion in axial position within the lumen of the first suture
portion.
In another aspect of the invention, a single-tailed suture is disclosed for
securing a plurality of body components together. The inventive single-tailed
suture comprises a length of braided suturing material having a distal portion
and a
proximal portion, and a braided outer wall which defines an internal lumen,
wherein the braided suturing material extends through one of the body
components,
such as a tendon. A distal end of the braided suturing material extends
through the
outer wall of the proximal portion so that a predetermined length of the
distal suture
portion is disposed within the lumen of a predetermined length of the proximal
suture portion. The predetermined length of the proximal suture portion is in
tension to create a binding interface between the predetermined length of the
distal
suture portion and the predetermined length of the proximal suture portion to
create
a suture loop.
In yet another aspect of the invention, a method of suturing a plurality of
body components together is described, wherein the inventive method uses a
length
of braided suturing material which comprises a plurality of flexible filaments
loosely woven together in a tubular geometry comprising an outer wall which
defines an internal lumen. A first step in the inventive method is to insert a
distal
end of the suturing material through a portion of a first one of the body
components, wherein the body components may comprise soft connective tissues
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such as tendons or ligaments, and/or bone. Then, a predetermined length of a
portion of the braided suturing material which is proximal to the first body
component is compressed, so that an internal diameter of the lumen of the
compressed suture portion increases substantially in size. At this juncture, a
distal
end of the length of braided suturing material is inserted through the outer
wall of
the compressed suture portion and into the internal lumen thereof, so that a
desired
length of the braided suturing material which is distal to the first body
component is
disposed within the internal lumen of the compressed suture portion.
Once the foregoing steps have been performed, and the compressed suture
portion is moved to a desired point, so that the resultant suture loop will be
of a
preferred size, tension is applied to the compressed suture portion to
decrease the
internal diameter of its lumen, to thereby create a binding interface between
the
compressed suture portion and the suturing material disposed in its lumen, so
that
the aforementioned suture loop of a desired length is formed.
The invention, together with additional features and advantages thereof,
may best be understood by reference to the following description taken in
conjunction with the accompanying illustrative drawing.
Brief Description of the Drawings
FIG. 1 a is a schematic view illustrating a basic construction of hollow cords
or sutures of the type utilized in the present invention, in tension;
FIG. 1b is a schematic view similar to FIG. la, illustrating the hollow suture
of FIG. 1 a in compression, rather than tension;
FIG. lc is a schematic view similar to FIGS. la and 1b, illustrating the
creation of a binding interface between two portions of a hollow suture which
is of
a construction like that shown in FIGS. la and 1b, wherein one of the suture
portions is disposed within the internal lumen of the other of the suture
portions;
FIG. 1 d is an end view of the hollow suture illustrated in FIG. 1 a;
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to
FIG. Ie is an end view of the hollow suture illustrated in FIG. 1b;
FIG. 1 f is an end view of the hollow suture binding interface illustrated in
FIG. 1 c;
FIGS. 2 through 7 are schematic perspective views illustrating in sequence
an apparatus and method for forming a single tail suture in accordance with
the
present invention;
FIGS. 8 through 12 are schematic perspective views similar to FIGS. 2
through 7, illustrating in sequence an alternate apparatus and method for
forming a
single tail suture in accordance with the present invention;
FIGS. 13 through 16 are schematic perspective views illustrating in
sequence still another alternate apparatus and method for forming a single
tail
suture in accordance with the present invention;
FIGS. 17a through 17c are detail plan views of a fid, a suture needle, and an
adaptation of a suture needle to a fid, respectively;
FIG. 18 is a detail perspective view illustrating the fid combination of FIG.
17c as it is being inserted through the outer wall 118 of a suture 113a;
FIG. 19 is a detail perspective view of another embodiment of a fid;
FIGS. 20a through 20c are detail perspective views of an additional fid
embodiment;
FIGS. 21 through 27 are schematic perspective views illustrating in
sequence yet another alternate apparatus and method for forming a single tail
suture
in accordance with the present invention;
FIGS. 28 through 35 are schematic perspective views illustrating in
sequence still another alternate apparatus and method for forming a single
tail
suture in accordance with the present invention;
FIG. 36 is a perspective view of an inventive tool which may be used for
tensioning a single tail suture;
FIG. 37 is a perspective view of an alternative tensioning tool for use in
tensioning a single tail suture;
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FIGS. 38 through 40 are plan views, in sequence, illustrating yet another
alternative embodiment and method for creating and tensioning a single tail
suture;
and
FIGS. 41 through 43 are plan views similar to those of FIGS. 38 through 40,
illustrating, in sequence, a method by which the expanded braid of FIGS. 38-40
may be tensioned over the suture.
Description of the Preferred Embodiment
Referring now more particularly to the drawings, FIG. 1 a shows a
tensioned suture I 1 of a braided construction, in tension. The tension on the
suture
preferably sets characteristics of the suture so that it is of diameter D and
pitch P.
FIG. 1b shows the tensioned suture 11 loaded with axial compression to form a
compressed suture 13, the suture braid being designed so that its pitch and
diameter
are affected by the axial compression on the suture by a factor "n" as shown.
The
factor "n" is of such a value that it makes possible the passage of the
tensioned
suture 11, having the diameter D, through the center of the compressed suture
13.
The factor "n" is also of such a value that the interior of compressed suture
13
further provides for the passage of any instrument that is required for the
manipulation of the suture.
Tn a preferred configuration, the factor "n" ranges in value from a
minimum of about 1.5 to a maximum of about 15.0 in order to achieve acceptable
performance, with a range of about 2 to 4 being preferred.
When the tensioned suture 11 is passed through the compressed suture 13
and the compressed suture 13 is further manipulated to be tensioned about the
tensioned suture I 1, there is created a binding interface 15 of a length L
between
the tensioned suture 11 and the compressed suture 13 as shown in FIG lc. As
will
be shown, the nature of the binding interface 15 is related directly to the
tension in
compressed suture 13, the length L (which is approximately equal to the length
of
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12
the formerly compressed suture 13), and to an interface frictional factor. The
nature
of the binding interface 15 is fiuther directly related to the value of an
angle "Q",
which is defined as the angle of orientation of fibers 17 which form the
braided
outer cylindrical wall 1~ of the suture 11,13, relative to a longitudinal axis
19 of the
compressed suture 13, as shown in Fig, 1b. More particularly, the nature of
the
binding interface is related to the sine of angle Q. An important aspect of
the
present invention is the inventors' discovery of the ability to define and
control the
degree of binding interface between the sutures 11 and 13, thereby providing a
controllable means of binding and securing sutures in tissue. In FIG. 1 c, the
binding interface 1S extends along a bound portion 24 of the suture, which is
approximately co-extensive with the length along which the tensioned suture 11
extends within the interior of the (formerly) compressed suture portion 13.
It is to be understood that hollow braided cord such as the suture 11
described supra is constructed using a number of separate fiber bundles
("picks")
which are woven together to form a braid. There is always an even number of
bundles, as an equal number of bundles are woven in each direction. A typical
number of bundles is 12, with 6 woven clockwise, and 6 woven counterclockwise.
For the purposes of understanding the relationship between the tension in the
suture
and the binding force, we will consider a single bundle, with the assumption
that
each bundle is subjected to the same forces and acts in a similar way within
the
structure of the hollow braided cord.
Considering a single fiber bundle 17 (FIG. 1b), it is seen that the geometry
described by that bundle within the braided cord is roughly helical, with
deviations
from a perfect helix to accommodate the over and under construction of
braiding.
For purposes of modeling the forces on the single fiber bundle 17, we will
consider
a single revolution of the bundle and smooth the bundle to a consistent helix,
recognizing that the forces on the bundle are consistent throughout the strand
and
along the length of the suture.
For ease of reference, the variables used in the following derivation are
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listed below:
T -- Tension in the hollow cord or suture
Q -- Angle formed by a single fiber bundle to the centerline of the hollow
cord
r -- Radius of the thin-walled cylinder approximating the hollow cord
t -- Wall thickness of the thin-walled cylinder
L -- Length of the hollow cord
S -- Stress
b -- Total number of fiber bundles in the hollow cord
w -- width of a single fiber bundle
N -- Normal force developed by a single fiber bundle
p -- Pressure generated by tension in the hollow cord
Ff -- Force generated by a single fiber bundle
Ft -- Total force generated by all of the fiber bundles b
Now, the binding interface is a frictional force developed as a result of the
normal force N exerted by the outer suture on the inner suture. The normal
force N
is equal to the pressure or hoop stress developed, multiplied by the area. The
tension T in the suture creates a pressure which is a function of the angle Q
formed
by the single bundle 17 to the centerline 19 of the hollow cord. It may be
understood that, as the angle Q approaches zero, the induced pressure
approaches
zero. For purposes of calculation, the hollow cord may be mathematically
approximated as a thin-walled cylinder of radius r, wall thicl~ness t, and
length L.
Stress, represented by S, for thin-walled cylinders is represented by the
equation:
t - ~, (1)
(from page 325, Mechanics of Materials, Beer and Johnston, McGraw-Hill Book
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Company, 1981), which, solving for stress S yields:
s = p~
The component of the force developed by the tension T in the cord which is
normal
to the centerline of the cord is expressed as:
T ~ sin Q (3)
We can equate the stress S in the cord to the force per unit area developed by
the
tension T in the cord, where the area A is defined by the thickness t
multiplied by
the width w of a single fiber bundle. Now the total tension T is distributed
throughout all of the fiber bundles b, and so the tension in a single fiber
bundle is:
T
to b (4)
Therefore, we see:
p~ T sin Q
t btvv (5)
and, solving for p, we get:
T sin Q
p bw~ (6)
Now, the normal force generated by this pressure is the pressure times the
unit area,
with the area being equal to the circumference of the cylinder times the
width, or:
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w2~c~T sin Q
N ~ ~'4 bwr (
and simplifying, we get:
T
N = 2~t b sin Q (8)
As will be understood by those skilled in the art, frictional force is equal
to the
5 normal force multiplied by a friction coefficient, normally represented by
~. The
equation then becomes:
Ff = ,uN = 2,u~cT sin Q (9)
The total force developed over all of the fiber bundles b of the hollow cord
with a
length L and a number of fiber bundles or picks per inch of k then becomes:
to Fr = 2kL,u~cT sin Q 10
b2 ( )
It may be seen from this equation that in order for the single-tail suture of
the
present invention to lock, F must be larger than T, and therefore the constant
2kL,u~c sing
b2 must be larger than one.
Now, the frictional coefficient ~ is simply a material property, and lc (picks
15 per inch), L (length), Q (angle between the centerline and the pick), and b
(total
number of picks) are design parameters. It may be seen, therefore, that by
judicious
selection of the constants k, L, Q, and b, a self locking system may be
developed
that optimizes the bound interface.
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Now with particular reference to FIGS. 2-7, wherein lilce or functionally
equivalent elements to those illustrated in prior embodiments are designated
by like
reference numerals, preceded by the numeral 1, there is illustrated one
preferred
embodiment of this bound interface which will serve to attach a suture loop 21
(Figs.3-7) to one piece of tissue 23. Suturing material 111, forming the
suture loop
21, is of a braided construction which will allow a needle or fid 27 to pass
through
the center of the compressed portion 113 of the braided suture 111 when it is
in
compression. The fid 27 may be passed through the tissue 23 by common
instruments of the art. Refernng to FIG. 3, the compressed portion 113 is
created
by manipulation of the braided sheath (typically the practitioner's fingers
are used
to "bunch" the fibers 117 forming the braided sheath together in compression
along
a portion of the length of the suture 111) and access to an interior lumen 29
is
identified. The fid 27 is then inserted into the interior lumen 29, as shown
in FIG.
4. Once inserted, the fid 27 is drawn out of the end of the compressed portion
113
and optionally clipped off, as shown in FIG. 5. The compressed portion 113 is
then
pushed, sliding it along the tensioned suture 111 to create the desired suture
Loop 21
geometry, as shown in FIG. 6. Of course, as will be appreciated, the
compressed
portion 113 is literally merely a portion of the tensioned suture 111 which
has been
manipulated into a compressed (or "bunched") state. Thus, it is not literally
"pushed". Rather, by sliding one's fingers or another suitable instrument
along the
Length of the tensioned suture 111, behind the compressed portion 113, one can
"move" the compressed portion 113 along the length of the suture 111
(literally
changing the portion of the length of the suture 111 which is in compression,
in the
manner similar to that of a standing wave).
Once the desired suture loop 21 geometry has been achieved, it can be
"locked" into place by applying tension on the compressed portion 113, as
shown in
Fig. 7, until the interior lumen 29 thereof decreases in diameter sufficiently
to
engage the portion of tensioned suturing material 111 which is disposed
therein.
This creates a binding interface 115 between portions 113 and 111 of the
suture, the
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binding interface I 15 being designed in length and pitch of braid to provide
a
bound end 124 to the suture loop 21 when suture 21 is in tension.
Now with particular reference to FIGS. 8-12, there is illustrated a second
preferred embodiment of this bound interface, wherein like or functionally
equivalent elements to those in previous embodiments are designated by like
reference numerals, preceded by the numeral 2. In this embodiment, a suture
loop
221 is to be attached to a piece of tissue 223. Suture loop 221 is comprised
of a
suturing material 211 which is of a braided construction. This braided
construction
allows a fid in the form of a hook 227, which includes a distal hook portion
30, to
pass through the center of a compressed portion 213 of the braided suture 211
. The
hook 227 is passed through the tissue 223 by common instruments of the art. A
flexible loop 31 resides in the interior of the compressed portion 213 and
functions
to aid in the management of the hook 227 as it travels through the compressed
portion 213. The hook 227, and, in particular, the distal hook portion 30
thereof, is
placed in the distal portion of the flexible loop 3 I, as shown in FIG. 9. The
hook
227 is then drawn into the interior of the compressed portion 2I3 of the
suture and
through a port 35 into the interior lumen 229 within the compressed portion
213 by
pulling the proximal end of the flexible loop 31, as shown in FIG. 10. The
hook
227 is then drawn out of the compressed portion 213 of the suture and
optionally
clipped off (FIG, 11). The compressed portion 213 of the suture is then
pushed,
sliding it along the suture 211 to create the desired Loop geometry 221, as
illustrated
in FIG. 12. Tension is then applied on the compressed portion 213 of the
suture to
generate a bound portion 224 (FIG. 12) of the suture having a binding
interface 215,
the binding interface 215 being designed in length and pitch of braid to
provide a
bound end 224 to the suture loop 221 when suture 211 is in tension.
The flexible nature of the looped component 31 of FIGS. 8-12 is desirable
in circumstances that require both ends of the suture to flex in order to
manage the
suture attachment to the tissue.
FIGS. 13-16 depict another embodiment in which one tail of the suture can
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be rigid throughout the procedure. In this embodiment, wherein like or
functionally
equivalent elements to those in previous embodiments are designated by like
reference numerals preceded by the numeral 3, a suture 311 is of a braided
construction which will allow a fid in the form of a barb 327 to pass through
the
center of a compressed portion 313 of the braided suture 31. The barb 327 is
passed through tissue 323 by common instruments of the art. A rigid component
331 resides in the interior of the compressed portion 313 and functions to aid
in the
management of the barb 327 as it travels through the compressed portion 313.
The
barb 327, and, in particular, a distal barb portion 330 thereof, is placed in
the distal
portion of the rigid component 331, as shown in FIG. 14. The barb 327 is then
drawn into an interior lumen 329 of the compressed portion 313 of the suture
3I 1
through a port 335 by pulling the proximal end of the rigid component 331,
illustrated in FIG. 15. The barb 327 is then drawn out of the compressed
suture 313
and optionally clipped off, as illustrated in FIG. 16. The compressed suture
313 is
then pushed to create the desired loop geometry. Tension is applied on the
compressed portion 313 of the suture 311 to generate a bound portion 324
thereof, a
binding interface 315 being designed in length and pitch of braid to provide a
bound end to a suture loop 321 when the bound portion 324 is in tension.
Presented thus far are 3 different manifestations of the self binding suture
loop.
The first, shown in FIGS. 2-7, addresses an embodiment which lends itself to
suturing
in an environment where generous flexible access to both suture ends is
available. The
second embodiment, illustrated in FIGS. 8-12, lends itself to an environment
where
restricted flexible access to both suture ends is available. The third
embodiment,
shown in FIGS. 13-16, lends itself to an environment where restricted access
is
available to both ends of the suture, but one end of the suture can remain
rigid
throughout the procedure. In all of these disclosed embodiments there resides
the
common requirement of one suture end 27, 227, 327, for negotiating a path
through the
compressed suture 13, 113, 213, 313. In two of the embodiments, receptacles
31, 331
are utilized to receive the suture end 27, 327, respectively.
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The fid 27 in FIGS. 2-7 represents a preferred embodiment of a fid, in the
form of a needle, which will pass easily through the internal lumen of the
braided
suture 113. A specific procedure may require the fid 27 to be sharp or pointed
for
the purposes of easily navigating through tissue, as shown in a fid 27a in
FIGS. 17b
and 17c. Should this be the case, it is preferred that a cap 37 be employed
(FIGS
17a and 17c), which fits snugly and securely onto the tip of the fid 27a, for
the
purposes of easily navigating through an interior lumen 29 (FIG. 3).
If it becomes difficult to access the interior lumen 29a of the compressed
braid portion 113a with any of the devices shown in the previous embodiment,
FIG.
18 illustrates a modified embodiment of the invention which includes a grommet
50, either flexible or rigid, that functions to supplement access of the fid
27a of
FIG. 17c, for example, into the lumen 29a of the compressed suture portion
113a.
The example shown is illustrative only, in that such a grommet could be
incorporated into any of the prior embodiments heretofore illustrated.
FIG. 19 illustrates an alternative embodiment to that illustrated in FIG. 8,
for example, wherein hook 227 is utilized to engage the flexible loop 3I. Such
hooks 227 are not preferred in all sizes of sutures or in all procedures. In
smaller
environments, where visualization of the hook can be difficult, it is
preferred to
utilize a hook 227a, as shown in FIG. 19, which has a tab portion 41 that is
predisposed to accept a suture loop. As shown, the hook 227a also includes a
piercing tip 42. The tab portion 41 protrudes outwardly in a manner that makes
it
easy to capture a suture loop, such as suture loop 31 shown in FIG. 8. After
the
suture loop is captured, the tab portion 41 is sufficiently flexible so as to
permit the
suture loop to slide distally into an eyelet 43. Once connected to the eyelet
43, the
suture loop draws the tab portion 41 into the interior of the braided suture.
FIGS. 20a-c, wherein like or functionally equivalent elements to those in
previous embodiments are designated by like reference numerals preceded by the
numeral 4, show an additional alternative embodiment for a hook-type fid
device
which is preferred in larger suture sizes in normal visualization
environments.
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Referring now to FIG. 20a there may be seen a suture 411 to which is attached
a
hook 427, which includes a tab portion 441. The tab portion 441 is made
accessible
by bending the hook 427 as shown in FIG. 20b. FIG. 20c illustrates a loop
portion
431 that has been looped around the tab portion 441. This mechanical
attachment
S will allow for the suture 411 to be pulled into an interior lumen 429 within
a
compressed portion 413 of the suture 411.
FIGS. 21-27 illustrate a method by which a self binding suture is used to
attach two pieces of tissue together. In this embodiment, like or functionally
equivalent elements to those in previous embodiments are designated by like
10 reference numerals preceded by the numeral 6. Two pieces of tissue 623a,b
are
beneath the skin and accessed via a cannula 45. A fid in the form of a needle
627
attached to the end of a suture 611 is passed through both pieces of tissue
623a and
623b using conventional methods, as shown in FIG. 21. The fid 627 is then
passed
through a loop 47 at the distal end of a snare 49, as shown in FIG. 22. The
snare is
15 pulled tight by pulling on a tab 51 at a proximal end of the snare 49, as
illustrated in
FIG. 23. The snare 49 is then pulled up into the interior Iumen 629 of the
compressed braided suture 613, dragging the fid 627 along with it (FIGS. 24
and
2S). The snare 49 is then removed from the suture and the fid 627 is
optionally cut
off, as shown in FIG. 26. At this juncture, the outer portion of the
compressed
20 portion 613 may be pushed down into the cannula 45 while the cut tail of
the suture
611 is pulled, creating the forces necessary to draw the tissue portions 623a
and
623b together, as shown in FIG. 27. Once drawn together, tension on the
binding
interface 61 S of the suture 611 creates a binding force that locks the
proximal ends
of the suture together, creating a bound portion 624 of the suture.
2S FIGS. 28-3S show another alternative embodiment and method in which the
self binding suture concept of the present invention is used in a suturing
device to
attach two pieces of tissue together. In this embodiment, like or functionally
equivalent elements to those in previous embodiments are designated by like
reference numerals preceded by the numeral 7. The suturing device in this
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embodiment comprises a rigid catch 731 that also acts as a piercing element.
With
reference to FIG. 28, Catch 731 is mechanically linked to a curved needle 727
through an articulating mechanism 53 which is capable of guiding the needle
727
into the distal features of the catch 731. Two pieces of tissue 723a, 723b are
beneath a patient's skin 55 and accessed via a cannula 745. The catch 731 is
pushed into the tissue 723a, 723b so that its distal end pierces the tissue,
as shown
in FIG. 29. The articulating mechanism 53 is then actuated so that a piercing
driver
57 drives needle 727 through the opposing tissue 723a, 723b and into the catch
731,
as illustrated in FIG. 30. Catch 731 is then pulled up to catch needle tip
727, as
shown in FIG. 31.
At this point, the articulating mechanism 53 is reversed to back out piercing
driver 57 from the needle tip 727 (FIG, 32). The needle tip 727 is rigid, in
order to
provide for a secure engagement with catch 731. The proximal end 59 of the
needle
727, however, is formed of a flexible material so as to enable the needle tip
727 and
its supporting portions to follow the catch 731 upwardly into the compressed
portion 713 of the suture, as shown in FIGS. 33 and 34. When the catch 731 is
withdrawn from the compressed portion 713, as illustrated in FIG. 35, thereby
pulling the needle 727 along, a binding interface 715 is formed along a bound
portion 724 of the suture.
In the preceding described self binding suture embodiments, the elements
common to each are as follows:
1) a braided tensioned suture represented by reference numerals ending
with "11" (hereinafter designated as "11");
2) a portion of the suture 11 that is radially expanded as a result of it
being
under compression, represented by reference numbers ending with "13",
hereinafter
designated as "13 ", through which one tail of the suture I 1 is threaded,
optionally
with the aid of a fid or similar tapered rigid portion, represented by
reference
numbers ending with "27", herein designated by "27";
3) a catch or loop, represented by references numbers ending with "31 ",
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herein designated as "31 ".
Once the tail 27 is threaded baclc through the expanded portion 13 of the
suture,
tension on the expanded portion 13 draws the suture down on the suture tail 27
to
create a binding interface represented by numbers ending in "15", herein
designated
by "15". The tension that is put on the expanded portion 13 must be applied in
a
specific manner to be most effective. The tension must preferably be applied
continuously in a constant motion starting at the distal end of compressed
suture
portion 13 and moving toward the proximal end thereof. This is most easily
accomplished by grasping the distal end of suture portion 13 between the thumb
and fore finger and sweeping the length of thereof to its proximal end while
holding
the threaded tail 27 in the other hand. Many applications of the invention
provide
for such manual access to the distal and proximal ends of compressed suture
portion
13 and need no other devices for the creation of the binding interface 15.
However,
there are other potential applications of the inventive concept for which
access to
the proximal and distal ends of the compressed suture portion 13 are limited.
In such applications, FIG. 36 illustrates a device or, more particularly, a
tensioner 63 which provides a means for applying the proper amount of tension
to
the compressed suture portion 13, from its distal end to the proximal end
thereof, in
order to create the bound suture portion 24, comprising a binding interface 15
between the expanded suture length and the tensioned suturing material
extending
through its internal lumen. The tensioner 63 includes a shaft 65 that is long
enough
to allow sufficient access to the distal end of the compressed portion 13. At
the end
of this shaft is disposed a head 67 having a slot 69, wherein the head is
formed of
material which will fractionally interact with the suture so as to apply the
desired
frictional tension thereto when portions of the compressed suture 13 extend
through
the slot. Tn operation, the tensioner shaft 65 is manipulated so that the head
67 is
disposed at the distal end of the compressed suture portion 13, whereupon the
suturing material is engaged within the slot 69. Then, the tensioner 63 is
withdrawn
proximally toward the practitioner, thereby functioning to "smooth down" or
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tension the compressed suture portion 13 as it travels therealong.
Another provision for a tensioner is one which may be integrated into the
suture, in either a rigid or flexible manner, is shown, fox example, in FIG
37. In
this embodiment, a modified tensioner device 71 is illustrated, which
comprises a
tubular structure 73. The tubular structure 73 may be fabricated of either
flexible or
rigid materials, and includes a flared portion 75 at its distal end. The outer
dimensions of the flared portion 75 are sufficiently large so that it binds
with the
interior surface of the lumen 29 within the compressed suture portion 13. This
binding interface between the tensioner 71 and the compressed suture portion
13
supplies the tension required to create a binding interface between the
compressed
suture portion I3 and the suture I 1 extending through the lumen 29 thereof
when
the tensioner 71 is pulled proximally out of the lumen 29. The interior of the
tubular structure 73 provides for the passage of all necessary fads, such as
hooks,
snares, and needles, fox assisting passage of the suture 11 through the lumen
29.
The flared portion 75 may also have an interior that facilitates the
management of
fid devices into the interior of the braid.
In all the heretofore disclosed embodiments, the radially expanded section
13 of the suture is held open by compressing that section of the suture. In
order to
draw a fid into the center of the braid, one hand is required to push on the
suture
and the other to draw or push the fid 27 into the center of the braid.
However, the
inventors have discovered a method for holding the braid open throughout the
process of managing the fid device that also serves to tension the suture
portion 13
in the final stages of creating the binding interface 15. Accordingly, FIGS.
38-43
illustrate such a method. More particularly, FIG. 38 illustrates shows an
expanded
braid 79 encapsulated in a tubular member 81, wherein the tubular member 81
has
an interior lumen 83 large enough to accept a fid 85 that is in the process of
completing a suture loop. A preferred approach would be to over-extrude the
tubular member 81 onto the braided portion 79 to achieve this configuration.
In
FIG. 39 there is shown the fid 85 passing through the interior of the expanded
braid
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79 and exiting proximally. FIG. 40 shows the suture tail 87 completely in the
expanded portion of the expanded braid 79.
Once the suture 87 is fully in place within the expanded braid 79, the
expanded braid can be tensioned over the suture. This tensioning procedure is
illustrated in FIGS. 41-43. Tensioning is accomplished by pulling the proximal
portion of the tube 81 with such force, in the direction shown by arrows A, as
is
necessary to delaminate the braid 79 from the tube's interior surface 88. This
force
is in a direction and of sufficient strength to tension the binding interface
distally to
the proximal end as is required, resulting in a bound portion 89 (FIG. 43).
The apparatus and method of the present invention may be embodied in
other specific forms without departing from its spirit or essential
characteristics.
The described embodiments are to be considered in all respects only as
illustrative
and not restrictive. The scope of the invention is, therefore, indicated by
the
appended claims rather than by the foregoing description. All changes which
come
within the meaning and range of equivalency of the claims are to be embraced
within their scope.
