A suture loop is formed in a hollow braided suture by feeding one end of a length of suture through a part in the braid of the suture and into the inner lumen formed by the hollow braid. The braided configuration of the suture allows it to be expanded in diameter by pushing and reduced in diameter by pulling. Said end of suture is passed continuously through said inner lumen forming a loop of suture with a single tail. The loop may be tightened by pulling on said first end of the suture while pushing on said outer hollow braid. The loop may be locked by extending or pulling on said outer hollow braid to reduce its diameter and lock it down around said first end of the suture.

BACKGROUND 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. Another knot called a Roeder knot was developed to allow surgeons to place a loop of suture around 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. Pat. 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 instrumentation 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 3 mm and 30 mm and a length of about 150 mm (6 inches). A commonality in these procedures is that the spaces in which the surgeon works are limited, and the tools used for suturing make tying knots difficult at best. Surgeons are accustomed to handling the suture, as knots in open procedures are typically tied and pushed down to the wound using the fingers. In endoscopic procedures, either the knots 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 picked 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 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 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 for 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 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 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 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.

SUMMARY OF 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 sutures. These sutures, commonly constructed out of silk, 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 lumen 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 fids, 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 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 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.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now more particularly to the drawings,FIG. 1ashows a tensioned suture11of 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. 1bshows the tensioned suture11loaded with axial compression to form a compressed suture13, 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 suture11, having the diameter D, through the center of the compressed suture13. The factor “n” is also of such a value that the interior of compressed suture13further provides for the passage of any instrument that is required for the manipulation of the suture.

In 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 suture11is passed through the compressed suture13and the compressed suture13is further manipulated to be tensioned about the tensioned suture11, there is created a binding interface15of a length L between the tensioned suture11and the compressed suture13as shown in FIG1c. As will be shown, the nature of the binding interface15is related directly to the tension in compressed suture13, the length L (which is approximately equal to the length of the formerly compressed suture13), and to an interface frictional factor. The nature of the binding interface15is further directly related to the value of an angle “Q”, which is defined as the angle of orientation of fibers17which form the braided outer cylindrical wall18of the suture11,13, relative to a longitudinal axis19of the compressed suture13, as shown inFIG. 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 sutures11and13, thereby providing a controllable means of binding and securing sutures in tissue. InFIG. 1c, the binding interface15extends along a bound portion24of the suture, which is approximately co-extensive with the length along which the tensioned suture11extends within the interior of the (formerly) compressed suture portion13.

It is to be understood that hollow braided cord such as the suture11described 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 bundle17(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 bundle17, 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 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

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 bundle17to the centerline19of 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 thickness t, and length L. Stress, represented by S, for thin-walled cylinders is represented by the equation:

S=p⁢⁢rt(2)
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·sinQ(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:

p=T⁢⁢sin⁢⁢Qb⁢⁢wr(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:

N=2⁢⁢π⁢⁢Tb⁢sin⁢⁢Q(8)
As will be understood by those skilled in the art, frictional force is equal to the normal force multiplied by a friction coefficient, normally represented by μ. The equation then becomes:
Ff=μN=2μπTsinQ(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:

Ft=2⁢k⁢⁢L⁢⁢μπ⁢⁢T⁢⁢sin⁢⁢Qb2(10)
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

2⁢k⁢⁢L⁢⁢μπsin⁢⁢Qb2
must be larger than one.

Now, the frictional coefficient μ is simply a material property, and k (picks 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.

Now with particular reference toFIGS. 2–7, wherein like or functionally equivalent elements to those illustrated in prior embodiments are designated by like reference numerals, preceded by the numeral1, there is illustrated one preferred embodiment of this bound interface which will serve to attach a suture loop21(FIGS. 3–7) to one piece of tissue23. Suturing material111, forming the suture loop21, is of a braided construction which will allow a needle or fid27to pass through the center of the compressed portion113of the braided suture111when it is in compression. The fid27may be passed through the tissue23by common instruments of the art. Referring toFIG. 3, the compressed portion113is created by manipulation of the braided sheath (typically the practitioner's fingers are used to “bunch” the fibers117forming the braided sheath together in compression along a portion of the length of the suture111) and access to an interior lumen29is identified. The fid27is then inserted into the interior lumen29, as shown inFIG. 4. Once inserted, the fid27is drawn out of the end of the compressed portion113and optionally clipped off, as shown inFIG. 5. The compressed portion113is then pushed, sliding it along the tensioned suture111to create the desired suture loop21geometry, as shown inFIG. 6. Of course, as will be appreciated, the compressed portion113is literally merely a portion of the tensioned suture111which 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 suture111, behind the compressed portion113, one can “move” the compressed portion113along the length of the suture111(literally changing the portion of the length of the suture111which is in compression, in the manner similar to that of a standing wave).

Once the desired suture loop21geometry has been achieved, it can be “locked” into place by applying tension on the compressed portion113, as shown inFIG. 7, until the interior lumen29thereof decreases in diameter sufficiently to engage the portion of tensioned suturing material111which is disposed therein. This creates a binding interface115between portions113and111of the suture, the binding interface115being designed in length and pitch of braid to provide a bound end124to the suture loop21when suture21is in tension.

Now with particular reference toFIGS. 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 numeral2. In this embodiment, a suture loop221is to be attached to a piece of tissue223. Suture loop221is comprised of a suturing material211which is of a braided construction. This braided construction allows a fid in the form of a hook227, which includes a distal hook portion30, to pass through the center of a compressed portion213of the braided suture211. The hook227is passed through the tissue223by common instruments of the art. A flexible loop31resides in the interior of the compressed portion213and functions to aid in the management of the hook227as it travels through the compressed portion213. The hook227, and, in particular, the distal hook portion30thereof, is placed in the distal portion of the flexible loop31, as shown inFIG. 9. The hook227is then drawn into the interior of the compressed portion213of the suture and through a port35into the interior lumen229within the compressed portion213by pulling the proximal end of the flexible loop31, as shown inFIG. 10. The hook227is then drawn out of the compressed portion213of the suture and optionally clipped off (FIG. 11). The compressed portion213of the suture is then pushed, sliding it along the suture211to create the desired loop geometry221, as illustrated inFIG. 12. Tension is then applied on the compressed portion213of the suture to generate a bound portion224(FIG. 12) of the suture having a binding interface215, the binding interface215being designed in length and pitch of braid to provide a bound end224to the suture loop221when suture211is in tension.

The flexible nature of the looped component31ofFIGS. 8–12is desirable in circumstances that require both ends of the suture to flex in order to manage the suture attachment to the tissue.

FIGS. 13–16depict another embodiment in which one tail of the suture can 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 numeral3, a suture311is of a braided construction which will allow a fid in the form of a barb327to pass through the center of a compressed portion313of the braided suture31. The barb327is passed through tissue323by common instruments of the art. A rigid component331resides in the interior of the compressed portion313and functions to aid in the management of the barb327as it travels through the compressed portion313. The barb327, and, in particular, a distal barb portion330thereof, is placed in the distal portion of the rigid component331, as shown inFIG. 14. The barb327is then drawn into an interior lumen329of the compressed portion313of the suture311through a port335by pulling the proximal end of the rigid component331, illustrated inFIG. 15. The barb327is then drawn out of the compressed suture313and optionally clipped off, as illustrated inFIG. 16. The compressed suture313is then pushed to create the desired loop geometry. Tension is applied on the compressed portion313of the suture311to generate a bound portion324thereof, a binding interface315being designed in length and pitch of braid to provide a bound end to a suture loop321when the bound portion324is in tension.

Presented thus far are 3 different manifestations of the self binding suture loop. The first, shown inFIGS. 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 inFIGS. 8–12, lends itself to an environment where restricted flexible access to both suture ends is available. The third embodiment, shown inFIGS. 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 end27,227,327, for negotiating a path through the compressed suture13,113,213,313. In two of the embodiments, receptacles31,331are utilized to receive the suture end27,327, respectively.

The fid27inFIGS. 2–7represents a preferred embodiment of a fid, in the form of a needle, which will pass easily through the internal lumen of the braided suture113. A specific procedure may require the fid27to be sharp or pointed for the purposes of easily navigating through tissue, as shown in a fid27ainFIGS. 17band17c. Should this be the case, it is preferred that a cap37be employed (FIGS. 17aand17c), which fits snugly and securely onto the tip of the fid27a, for the purposes of easily navigating through an interior lumen29(FIG. 3).

If it becomes difficult to access the interior lumen29aof the compressed braid portion113awith any of the devices shown in the previous embodiment,FIG. 18illustrates a modified embodiment of the invention which includes a grommet50, either flexible or rigid, that functions to supplement access of the fid27aofFIG. 17c, for example, into the lumen29aof the compressed suture portion113a. The example shown is illustrative only, in that such a grommet could be incorporated into any of the prior embodiments heretofore illustrated.

FIG. 19illustrates an alternative embodiment to that illustrated inFIG. 8, for example, wherein hook227is utilized to engage the flexible loop31. Such hooks227are 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 hook227a, as shown inFIG. 19, which has a tab portion41that is predisposed to accept a suture loop. As shown, the hook227aalso includes a piercing tip42. The tab portion41protrudes outwardly in a manner that makes it easy to capture a suture loop, such as suture loop31shown inFIG. 8. After the suture loop is captured, the tab portion41is sufficiently flexible so as to permit the suture loop to slide distally into an eyelet43. Once connected to the eyelet43, the suture loop draws the tab portion41into 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 numeral4, show an additional alternative embodiment for a hook-type fid device which is preferred in larger suture sizes in normal visualization environments. Referring now toFIG. 20athere may be seen a suture411to which is attached a hook427, which includes a tab portion441. The tab portion441is made accessible by bending the hook427as shown inFIG. 20b.FIG. 20cillustrates a loop portion431that has been looped around the tab portion441. This mechanical attachment will allow for the suture411to be pulled into an interior lumen429within a compressed portion413of the suture411.

FIGS. 21–27illustrate 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 reference numerals preceded by the numeral6. Two pieces of tissue623a,bare beneath the skin and accessed via a cannula45. A fid in the form of a needle627attached to the end of a suture611is passed through both pieces of tissue623aand623busing conventional methods, as shown inFIG. 21. The fid627is then passed through a loop47at the distal end of a snare49, as shown inFIG. 22. The snare is pulled tight by pulling on a tab51at a proximal end of the snare49, as illustrated inFIG. 23. The snare49is then pulled up into the interior lumen629of the compressed braided suture613, dragging the fid627along with it (FIGS. 24 and 25). The snare49is then removed from the suture and the fid627is optionally cut off, as shown inFIG. 26. At this juncture, the outer portion of the compressed portion613may be pushed down into the cannula45while the cut tail of the suture611is pulled, creating the forces necessary to draw the tissue portions623aand623btogether, as shown inFIG. 27. Once drawn together, tension on the binding interface615of the suture611creates a binding force that locks the proximal ends of the suture together, creating a bound portion624of the suture.

FIGS. 28–35show 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 numeral7. The suturing device in this embodiment comprises a rigid catch731that also acts as a piercing element. With reference toFIG. 28, Catch731is mechanically linked to a curved needle727through an articulating mechanism53which is capable of guiding the needle727into the distal features of the catch731. Two pieces of tissue723a,723bare beneath a patient's skin55and accessed via a cannula745. The catch731is pushed into the tissue723a,723bso that its distal end pierces the tissue, as shown inFIG. 29. The articulating mechanism53is then actuated so that a piercing driver57drives needle727through the opposing tissue723a,723band into the catch731, as illustrated inFIG. 30. Catch731is then pulled up to catch needle tip727, as shown inFIG. 31.

At this point, the articulating mechanism53is reversed to back out piercing driver57from the needle tip727(FIG,32). The needle tip727is rigid, in order to provide for a secure engagement with catch731. The proximal end59of the needle727, however, is formed of a flexible material so as to enable the needle tip727and its supporting portions to follow the catch731upwardly into the compressed portion713of the suture, as shown inFIGS. 33 and 34. When the catch731is withdrawn from the compressed portion713, as illustrated inFIG. 35, thereby pulling the needle727along, a binding interface715is formed along a bound portion724of 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 suture11that 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 suture11is 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”, herein designated as “31”.
Once the tail27is threaded back through the expanded portion13of the suture, tension on the expanded portion13draws the suture down on the suture tail27to create a binding interface represented by numbers ending in “15”, herein designated by “15”. The tension that is put on the expanded portion13must 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 portion13and moving toward the proximal end thereof. This is most easily accomplished by grasping the distal end of suture portion13between the thumb and fore finger and sweeping the length of thereof to its proximal end while holding the threaded tail27in the other hand. Many applications of the invention provide for such manual access to the distal and proximal ends of compressed suture portion13and need no other devices for the creation of the binding interface15. However, there are other potential applications of the inventive concept for which access to the proximal and distal ends of the compressed suture portion13are limited.

In such applications,FIG. 36illustrates a device or, more particularly, a tensioner63which provides a means for applying the proper amount of tension to the compressed suture portion13, from its distal end to the proximal end thereof, in order to create the bound suture portion24, comprising a binding interface15between the expanded suture length and the tensioned suturing ma through its internal lumen. The tensioner63includes a shaft65that is long enough to allow sufficient access to the distal end of the compressed portion13. At the end of this shaft is disposed a head67having a slot69, wherein the head is formed of material which will frictionally interact with the suture so as to apply the desired frictional tension thereto when portions of the compressed suture13extend through the slot. In operation, the tensioner shaft65is manipulated so that the head67is disposed at the distal end of the compressed suture portion13, whereupon the suturing material is engaged within the slot69. Then, the tensioner63is withdrawn proximally toward the practitioner, thereby functioning to “smooth down” or tension the compressed suture portion13as 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, for example, inFIG. 37. In this embodiment, a modified tensioner device71is illustrated, which comprises a tubular structure73. The tubular structure73may be fabricated of either flexible or rigid materials, and includes a flared portion75at its distal end. The outer dimensions of the flared portion75are sufficiently large so that it binds with the interior surface of the lumen29within the compressed suture portion13. This binding interface between the tensioner71and the compressed suture portion13supplies the tension required to create a binding interface between the compressed suture portion13and the suture11extending through the lumen29thereof when the tensioner71is pulled proximally out of the lumen29. The interior of the tubular structure73provides for the passage of all necessary fids, such as hooks, snares, and needles, for assisting passage of the suture11through the lumen29. The flared portion75may 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 section13of 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 fid27into 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 portion13in the final stages of creating the binding interface15. Accordingly,FIGS. 38–43illustrate such a method. More particularly,FIG. 38illustrates shows an expanded braid79encapsulated in a tubular member81, wherein the tubular member81has an interior lumen83large enough to accept a fid85that is in the process of completing a suture loop. A preferred approach would be to over-extrude the tubular member81onto the braided portion79to achieve this configuration. InFIG. 39there is shown the fid85passing through the interior of the expanded braid79and exiting proximally.FIG. 40shows the suture tail87completely in the expanded portion of the expanded braid79.

Once the suture87is fully in place within the expanded braid79, the expanded braid can be tensioned over the suture. This tensioning procedure is illustrated inFIGS. 41–43. Tensioning is accomplished by pulling the proximal portion of the tube81with such force, in the direction shown by arrows A, as is necessary to delaminate the braid79from the tube's interior surface88. 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 portion89(FIG. 43).