Title of Invention

"BARBED SUTURES"

Abstract A barbed suture for connecting human or animal tissue, said suture comprising (a) an elongated body having a first end and a second end and (b) a plurality of barbs projecting from the body, each barb facing in a direction and being adapted for resisting movement of the suture, when in tissue, in an opposite direction from the direction in which the barb faces, the barbs having a disposition on the body selected from the group consisting of a staggered disposition, a multiple spiral disposition, an overlapping disposition, a random disposition, and combinations thereof.
Full Text TECHNICAL FIELD
This invention relates, in general, to a barbed suture useful for connecting bodily tissue in various surgical contexts, and more particularly, to the optimization of the disposition and/or configuration of the barbs on such barbed sutures
BACKGROUND OF THE INVENTION
Various surgical methods employing sutures have been used in the past for closing or binding together wounds in human or animal tissue, such as skin, muscles, tendons, internal organs, nerves, blood vessels, and the like More specifically, the surgeon may use a surgical needle with an attached conventional suture (which can be a smooth monofilament or can be a multi-filament) to pierce the tissue alternately on opposing faces of the wound and thus sew the wound closed Whether the wound is accidental or surgical, loop stitching is the method often used, espec lally for surface wounds The surgical needle is then removed and the ends of the suture are tied, typically with at least three overhand throws to form a knot
As is well known, conventional sutures can be of non-absorbable material such as silk, nylon, polyester, polypropylene, or cotton, or can be of bio-absorbable material such as glycohc acid polymers and copolymers or lactic acid polymers and copolymers
Since the time of their conception, barbed sutures, which are generally of the same materials as conventional sutures, have offered numerous advantages over closing wounds with conventional sutures A barbed suture includes an elongated body that has one or more spaced barbs, which project from the body surface along the body length The barbs are arranged to allow passage of the barbed suture in one direction through tissue but resist movement of the barbed suture in the opposite direction Thus, the main advantage of barbed sutures has been the provision of a non-slip attribute Accordingly, barbed sutures do not have to be knotted, like conventional sutures Like a conventional suture, a barbed suture may be inserted into tissue using a surgical needle
For instance, U S Patent No 3,123,077 to Alcamo describes an elongated cord for sewing human flesh, where the cord has a body portion and sharp-edged, resilient barbs projecting from the body at acute angles relative to the body The barbed suture can be passed through tissue m one direction, but resists movement in the opposite direction
Sutures with barbs disposed in a bi-directional arrangement, also called double-armed sutures, are shown in U S Patent No 5,931,855 to Buncke and U S Patent No 6,241,747 to
Ruff More particularly the suture has barbs facing toward one end of the suture for about half the suture length and barbs facing in the opposite direction toward the other end of the suture for the other half of the suture length This arrangement allows the barbs to move in the same direction as each respective suture end is inserted into the first and second sides of a wound Such bi-directional barbed sutures not only are especially suitable for closing wounds with edges prone to separation, but also obviate the need to secure suture ends together with knotted loops
Of interest is European Published Patent Application No 1,075,843 Al to Sulamamdze and Mikhailov, published February 2, 2001, derived from PCT/RU99/00263 (published as WO 00/51658 on September 8, 2000), priority to RU 99103732 (March 3, 1999), which shows conical barbs arranged sequentially along the length of a thread and onented in a direction opposite to that of the thread tension, with the distance between barbs being not less than 1 5 times the thread diameter
Also of interest is U S Patent No 5,342,376 to Ruff This patent shows an insertion device that is useful for positioning a barbed suture in order to close a wound The insertion device has a tubular body for receiving a barbed suture, and preferably also has a handle to facilitate manipulation of the device by the surgeon The insertion device is recommended for use with a barbed suture where the suture portion being inserted includes barbs facing a direction opposed to the direction of insertion Such sutures with barbs opposing the direction of insertion are also shown in '376 to Ruff
The disclosures of all patents and patent applications mentioned here are incorporated by reference
Escarpment of barbs into a monofilament, depending on the barb cut depth, reduces the straight pull tensile strength since the effective suture diameter is decreased However, the straight pull tensile strength of a barbed suture should be compared to the minimum knot pull strength of a conventional suture (a non-barbed suture) in accordance with the United States Pharmacopoeia since failure of conventional sutures (which have to be knotted and must meet a minimum knot pull tensile strength) occurs most frequently at the knot due to increased local stress
To optimize the performance of a barbed suture, it is advantageous to consider varying the barb geometry (barb cut angle, barb cut depth, barb cut length, barb cut distance, etc ) and/or the spatial arrangement of the barbs This should not only enhance the tensile strength of a barbed suture, but also should enhance the ability of a barbed suture in holding and maintaining wound edges together Unlike conventional sutures, which place tensions
directly at the knots, barbed sutures can spread out the tension along the escarped suture length, often evenly along the length Optimizing the disposition and/or the configuration of the barbs should therefore further increase the effectiveness of the new barbed suture in maximizing the holding strength and minimizing the gap formation along the wound edges The latter is particularly beneficial for promoting wound healing
Also, such new barbed sutures should approximate tissue quickly with appropriate tension, alleviate distortion of tissue, and help to minimize scarring, due to the self retaining benefits imparted by the barbs The new barbed sutures would be especially useful in surgeries where minimization of scarring is imperative, such as cosmetic surgery, as well as in surgeries where space is limited, such as endoscopic surgery or microsurgery
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a barbed suture for connecting human or animal tissue The barbed suture comprises an elongated body having a first end and a second end The barbed suture further comprises a plurality of barbs projecting from the body Each barb is adapted for enabling the barbed suture to resist movement, when in tissue, in the direction that is opposite from the direction in which that barb faces The barbed suture further comprises the barbs being disposed on the body in a disposition selected from a staggered disposition, a twist cut multiple spiral disposition, an overlapping disposition, a random disposition, or combinations thereof
For the staggered disposition, the twist cut multiple spiral disposition, and/or the overlapping disposition, the barbs may all be facing toward only one of the first and second ends Alternatively, the barbed suture may have at least a first portion and a second portion, where the barbs of the first portion are facing toward the first end and the barbs of the second portion are facing toward the second end
Also, in an alternative embodiment, the present invention provides a barbed suture for connecting human or animal tissue, where the suture comprises an elongated body having a first end and a sec ond end The suture further composes a plurality of barbs projecting from the body Each barb is adapted for enabling the suture to resist movement, when the suture is in tissue, in the direction that is opposite from the direction in which that barb faces The suture further comprises the barbs having a configuration selected from a barb cut angle 9 ranging from about 140 degrees to about 175 degrees, a barb cut depth with a ratio of cut depth to suture diameter ranging from about 0 05 to about 0 6, a barb cut length with a ratio
of cut length to suture diameter ranging from about 0 2 to about 2, a barb cut distance with a ratio of cut distance to suture diameter ranging from about 0 1 to about 6, a corrugated underside, an arcuate base, varying sizes, or combinations thereof
For the twist cut multiple spiral disposition, the barbed suture preferably has a spirality a angle langing from about 5 degrees to about 25 degrees
For the overlapping disposition, it is meant that at least two adjacent barbs are disposed where one overlaps the other During escarpment of the barbs, the overlapping is created by a barb (I. e, the overlapping barb) being escarped into the topside of another adjacent barb (1 e, the overlapped barb), and so on Hence, part of the topside of the overlapped barb becomes part of the underside of the overlapping barb, and so on Thus, with the overlapping disposition, the barb cut distance between the overlapping barb and the overlapped barb may be shorter than the barb cut length of overlapped second barb, whereas in general for barbed sutures, the barb cut distance between two barbs > the barb cut length
In still another embodiment, the present invention provides a barbed suture for connecting human or animal tissue in combination with a surgical needle, where the combination comprises a barbed suture attached to a surgical needle The suture comprises a plurality of barbs projecting from an elongated body having a first end and a second end Each barb is adapted for enabling the suture to resist movement, when the suture is in tissue in the direction that is opposite from the direction in which that barb faces The ratio of the surgical needle diameter to the suture diameter preferably is about 3 1 or less Suitably, any of the inventive barbed sutures described here may be attached to a surgical needle
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE 1A is a side view of one embodiment of the present invention, showing a
barbed suture with barbs disposed in a 180 degree staggered spacing,
FIGURE 1B is a sectional view along line 1B - 1B of the barbed suture in Figure 1A, FIGURE 2A is a side view of another embodiment of the present invention, showing
a barbed suture that is bi-directional with barbs disposed in a 180 degree staggered spacing, FIGURE 2B is a sectional view along line 2B - 2B of the barbed suture in Figure 2A, FIGURE 3A is a side view of another embodiment of the present invention, showing
a barbed suture with barbs disposed in a 120 degree staggered spacing,
FIGURE 3B is a sectional view along line 3B - 3B of the barbed suture in Figure 3A
DESCRIPTION
As used here, the term "wound" means a surgical incision, cut, laceration, severed tissue or accidental wound in human or animal skin or other human or animal bodily tissue, or other condition in a human or animal where sutunng, stapling, or the use of another tissue connecting device may be required
Also as used here, the term "tissue" includes, but is not limited to, tissues such as skin, fat, fascia bone, muscle, organs, nerves, or blood vessels, or fibrous tissues such as tendons or ligaments
Moreover, the term "polymer" as used here generally includes, but is not limited to, homopolymers, copolymers (such as block, graft, random and alternating copolymers), terpolymers, et cetera, and blends and modifications thereof Furthermore, the term 'polymer" shall include all possible structures of the material These structures include, but are not limited to, isotactic, syndiotactic, and random symmetries
Although Ihe sutures are described below in a preferred embodiment with a circular cross section, the sutures could also have a non-circular cross sectional shape that could increase the surface area and facilitate the formation of the barbs Other cross sectional shapes may include, but are not limited to, oval, triangle, square, parallelepiped, trapezoid, rhomboid, pentagon, hexagon, cruciform, and the like Typically, barbs are cut into a polymeric filament that has been formed by extrusion using a die with a circular cross section, and thus, the cross section of the filament will be circular, as that is what results during such extrusion However, extrusion dies can be custom made with any desired cross-sectional shape
Hence, the term "diameter" as used here is intended to mean the transverse length of the cross section, regardless of whether the cross section is circular or some other shape
Suitable diameters for the inventive sutures described below may range from about 0 001 mm to about 1 mm, and of course, the diameter may be from about 0 01 mm to about 0 9 mm, or from about 0 015 mm to about 0 8 mm The typical diameter ranges from about 0 01 mm to about 0 5 mm The length of the suture can vary depending on several factors such as the length and/or depth of the wound to be closed, the type of tissue to be joined, the location of the wound, and the like Typical suture lengths range from about 1 cm to about 30 cm, more particularly from about 2 cm to about 22 cm
The terms "staggered" and "staggering" as used here in relation to the disposition of barbs on a suture are intended to mean that the suture has at least two sets of barbs that are offset with respect to each other, where the first set is aligned longitudinally on the suture and
the second set is aligned longitudinally on the suture, but a plane perpendicular to the suture and cutting transversely through the suture and intersecting the base of a barb of the first set will not intersect the base of a barb of the second set
The barbs project from the exterior surface of the suture body on which the barbs are disposed Depending on the intended end use of the barbed suture, barbs of different sizes may be employed In general, larger barbs are more suitable for joining certain types of tissue such as fat tissue or soft tissue On the other hand, smaller barbs are more suitable for joining other types of tissue, such as collagen dense tissue
As noted above, barbed sutures may be made from the same matenals used for making conventional loop sutures Any particular chosen matenal for the barbed suture depends on the strength and flexibility requirements
More specifically, barbed sutures may be formed from a bio-absorbable matenal that allows the suture to degrade and thus to be absorbed over time into the tissue as the wound heals Generally, bio-absorbable matenals are polymenc, and depending on the particular polymer selected, the degradation time in the wound ranges from about 1 month to over 24 months The use of bio-absorbable matenals eliminates the necessity of removing the sutures from the patient
Vanous bio absorbable polymers include, but are not limited to, polydioxanone, polylactide, pol yglycolide, polycaprolactone, and copolymers thereof Commercially available examples are polydioxanone (sold as PDS II, a trade name used by Ethicon for selling surgical sutures), copolymer of about 67% glycolide and about 33% tnmethylene carbonate (sold as MAXON®, a trademark registered to Amencan Cyanamid for surgical sutures), and copolymer of about 75% glycolide and about 25% caprolactone (sold as MONOCRYL®, a trademark registered to Johnson & Johnson for sutures and suture needles) Barbed sutures made from such bio-absorbable matenals are useful in a wide range of applications
Additionally, barbed sutures may be formed from a non-absorbable matenal, which may be a polymer Such polymers include, but are not limited to, polypropylene, polyamide (also known as nylon), polyester (such as polyethylene terephthlate, abbreviated here as PET), polytetrafluoroethylene (such as expanded polytetrafluoroethylene, abbreviated here as ePTFE and sold by Gore as GOR-TEX®), polyether-ester (such as polybutester, which is the condensation polymenzation of dimethyl terephthlate, polytetramethylene ether glycol, and 1,4-butanediol, and which is marketed by Davis & Geek and by U S Surgical, companies
owned by Tyco, under the name NOVAFIL®, which is a trademark registered to American Cyanamid for surgical sutures), or polyurethane Alternatively, the non-absorbable material may be metal (e g , steel), metal alloys, natural fiber (e g , silk, cotton, et cetera), and the like
Most of the barbed sutures discussed below are descnbed as having their ends being pointed and formed of a material sufficiently stiff to allow for piercing tissue It is contemplated that the ends of the barbed sutures may comprise a surgical needle In this embodiment, the barbed suture is adapted for attachment, such as by swaging, channel wrapping, heat shrinking, or eyelet threading to the surgical needle for insertion into tissue
Attachment by swaging is well descnbed and is typically accomplished by inserting the suture end into the surgical needle hole that is longitudinally disposed at one end of the surgical needle (usually the hole has been dnlled longitudinally into one end of the needle), followed by camping the resultant about the needle hole so that the suture is secured to the surgical needle for insertion into tissue Also, some surgical needles with a longitudinal hole m one end are heat shnnkable tubes that are heat shrunk after insertion of the suture in order to attach the suture to the surgical needle Additionally, some surgical needles have a channel or trough at one end, and the suture is laid m the trough, followed by wrapping to secure the suture to the surgical needle Surgical needles with a conventional eyelet type of hole transversely disposed m one end of the surgical needle could also be used, but are not preferred for barbed sutures For the present invention, part of the discussion below regards surgical needles swaged with barbed sutures, but it is contemplated that any other suitable means of attaching needles can be employed
Attachment of sutures and surgical needles is descnbed in U S Patent No 3,981,307 Borysko, US Patent No 5,084,063 to Korthoff, US Patent No 5,102,418 to Granger et al, U S Patent No 5,123,911 to Granger et al, U S Patent No 5,500,991 to Demarest et al, US Patent No 5,722,991 to Colligan, U S Patent No 6,012,216 to Esteves et al, and U S Patent No 6,163,948 to Esteves et al A method for the manufacture of surgical needles is descnbed in US Patent No 5,533,982 to Rizk et al Further, it is noted that the surgical needle may be c oated, the coating allowing for the needle of the inventive combination surgical needle/barbed suture to be inserted into tissue with less force than if the surgical needle were not coated The coating may be a polymer, for instance, a silicone resin coating For example, an improved siliconized surgical needle that requires significantly less force to effect tissue penetration than a standard siliconized surgical needle is descnbed in U S Patent No 5,258,013 to Granger et al
The barbs are disposed in various arrangements on the body of the suture The barbs may be formed using any suitable method, including injection molding, stamping, cutting, laser, and the like With regard to cutting, m general, polymeric threads or filaments are purchased, and then the barbs are cut onto the filament body
The cutting may be manual, but that is labor intensive and not cost effective
A very suitable cutting machine is disclosed mUS Patent Application Serial No 09/943,733 to Genova et al, assignors to Quill Medical, filed August 31, 2001, the disclosure of which is incorporated by reference Such a cutting machine has a plurality of blades for escarpment of barbs onto a suture filament A typical cutting machine for manufacturing barbed sutures utilizes a cutting bed, a vise, one or more blade assemblies, and sometimes a template or guide for the blades The suture filament is placed m the bed and held by the vise, with the transverse direction of the blades generally disposed m the transverse direction of the suture filament, in order to cut a plurality of axially spaced barbs disposed on the exterior of a suture filament
With relerence now to the drawings, where like reference numerals designate corresponding or similar elements throughout the several views, shown in Figure 1A is a side view of a barbed suture according to the present invention and generally designated at 1
Suture 1 includes elongated body 2 that is generally circular in cross section and that terminates m end 4 End 4 is illustrated m one embodiment as being pointed for penetrating tissue, but it is contemplated that end 4 may compnse a surgical needle (not shown) for insertion into tissue (The other end is not shown ) Also, suture 1 includes plurality of closely spaced baibs 7, 9 arranged in a staggered uni-directional disposition More specifically, axially spaced barbs 7 are radially arranged about 180 degrees from and staggered with respect to axially spaced barbs 9, with barbs 7,9 facing pointed end 4 First set of barbs 7 define a plane that is substantially coplanar with the plane defined by second set of barbs 9, and consequently, barbs 7,9 define substantially the same one plane due to the radial 180 degree arrangement
Figure 1B which is a cross sectional view along line 1B - 1B of suture 1 in Figure 1 A, more clearly illustrates angle X, namely the radial 180 degree arrangement of barbs 7 with respect to barbs 9 As also can be seen from Figure 1B, the stippling illustrates that first barb 7 of barbs 7 is closer to pointed end 4 (not shown in Figure 1B), and thus, seems to be larger than farther away first barb 9 of barbs 9, due to the staggenng A transverse plane that is perpendicular to suture body 2 and that intersects the base of one barb 7 of barbs 7 does not intersect the base of any barb 9 of barbs 9
Suture 1 may be made with a cutting machine that produces two sets of barbs 7, 9, usually one set at a time, in a staggered position along suture 1, such as the cutting device described in the above-noted Serial No 09/943,733 to Genova et al
First set oi barbs 7 is created by placing and holding a suture filament in the vise, and then, the set of blades, with a predetermined length, splices into the suture filament at an angle selected to create barbs 7 pointing in one direction toward pointed end 4 Second set of barbs 9 is created similarly after offsetting the blades longitudinally (to create the staggering) approximately half of the longitudinal distance between two of barbs 7 and also rotating the suture filament about 180 degrees on the vise, which is equipped to accommodate first set of barbs 7 that are already cut
Shown m Figure 2A is suture 10, which is another embodiment of the present invention and is like suture 1, except that suture 10 is bi directional Suture 10 includes elongated body 1? that is generally circular in cross section Elongated body 12 terminates in first and second pointed ends 14, 16 for penetrating tissue Also, it is contemplated that one or both ends 14, 16 may comprise a surgical needle (not shown) for insertion into tissue Also, suture 10 includes plurality of closely spaced barbs 17,18, 19, 20 arranged in a staggered bi-dnectional disposition
More specifically, plurality of axially spaced barbs 17 are radially arranged about 180 degrees from and staggered with respect to plurality of axially spaced barbs 19, with barbs 17, 19 facing pointed end 14 for a portion (about half of the length) of suture 10 Similarly, plurality of axially spaced barbs 18 are radially arranged about 180 degrees from and staggered with respect to plurality of axially spaced barbs 20, with barbs 18, 20 facing pointed end 16 for another portion (approximately the other half of the length) of suture 10 First set of barbs 17, 18 define a plane that is substantially coplanar with the plane defined by second set of barbs 19, 20 As a result, all of barbs 17,18,19, 20 define substantially the same one plane due to the radial 180 degree arrangement of first set of barbs 17, 18 with respect to second set of barbs 19, 20
Figure 2B is a cross sectional view along line 2B - 2B of suture 10 in Figure 2A, more clearly illustrating angle X, namely the radial 180 degree arrangement Due to the staggering, first barb 17 of barbs 17 is closer to pointed end 14 (not shown in Figure 2B), and thus, appears larger than farther away first barb 19 of barbs 19, as is illustrated by the stippling A transverse plane that is perpendicular to suture body 12 and that intersects the base of one barb 17 of barbs 17 does not intersect the base of any barb 19 of barbs 19
Likewise, a transverse plane that is perpendicular to suture body 12 and that intersects the base of one barb 18 of barbs 18 does not intersect the base of any barb 20 of barbs 20
Suture 10 may be made with the same cutting machine as suture 1, such as the cutting device described m the above-noted Serial No 09/943,733 to Genova et al, except with the following change m blade direction
For first set of bi-directional barbs 17,18, after the suture filament is placed and held in the vise, the blades splice with a first cutting action into approximately half of the length of the suture filament to create barbs 17 facing in one direction toward pointed end 14 Next, the blades are rotated 180 degrees so that they are now disposed in the opposite direction and over the uncut half of the length The blades are then allowed to splice into the other half of the length of ths suture filament with a second cutting action to create barbs 18 facing in the opposite direction toward pointed end 16
Next, the blades are offset longitudinally (to create the staggering) about half of the longitudinal distance between two of barbs 17, and also the suture filament is rotated about 180 degrees on the vice, which is equipped to accommodate first set of bi directional barbs 17,18 that are already cut Then, for second set of bi-directional barbs 19, 20, the blades splice with a first cutting action into approximately half the length of the suture filament to create barbs 20 fa( ing in one direction toward pointed end 16 The first cutting action is followed by rotating the blades longitudinally 180 degrees so that they are now disposed in the opposite direction and over the uncut half of the length The blades are then allowed to splice into the other half of the length of the suture filament with a second cutting action to create barbs 19 facing in the opposite direction toward pointed end 14
In an alternative embodiment (not shown) for bi-directional suture 10, the portion of suture 10 with barbs 17, 19 may have them facing toward pointed end 16 and the portion of suture 10 with barbs 18, 20 may have them facing toward pointed end 14 With this variation, the barbed suture would be inserted into tissue with an insertion device, such as that shown m the above-noted U S Patent No 5,342,376 to Ruff Additionally, it is noted that, if desired, barbs may be escarped so that there may be two portions with barbs facing one end and one portion with barbs facing the other end, or two portions with barbs facing one end and two portions with barbs facing the other end, and so on (not shown), and thus, if a portion of barbs is not facing the suture end to which those barbs are adjacent, then, the barbed suture would be inserted into tissue with an insertion device
An advantage of a barbed suture having a radial 180 degree arrangement with staggering is that the 180 degree spacing is readily fabricated on relatively small diameter
filaments and the staggenng improves anchoring performance Thus, in thin and delicate tissue, where a smaller suture is desirable, the staggered 180 degree spacing generates effective anchoring performance
Turning now to Figure 3A, depicted is a side view of another embodiment of a suture according to the present invention, and generally designated at suture 30 Suture 30 is like suture 1 shown in Figure 1 A, except that the radial spacing for suture 30 is 120 degrees instead of 180 degrees as is shown for suture 1
More particularly, suture 30 includes elongated body 32 that is generally circular in cross section and that terminates in pointed end 34 for penetrating tissue It is contemplated that end 34 may compnse a surgical needle (not shown) so that the suture can be inserted into tissue (The other end is not shown ) Additionally, suture 30 includes plurality of closely spaced barbs 35, 37, 39 arranged so that all face in the same direction toward pointed end 34 Hence, the disposition of barbs 35, 37, 39 is uni-directional
Also, axial spaced barbs 35 are radially arranged about 120 degrees from and staggered with respect to axially spaced barbs 37, which are radially arranged about 120 degrees from and staggered with respect to axially spaced barbs 39 Hence, axially spaced barbs 39 are also arranged about 120 degrees from and staggered with respect to axially spaced barbs 35 As a result of the radial 120 degree arrangement, first set of barbs 35 define substantially the same one plane, second set of barbs 37 define substantially another same one plane, and third set of barbs 39 define substantially still another same one plane Thus, suture 30 has barbs 35, 37, 39 arranged m a staggered uni-directional 120 degree disposition
Figure 3B is a cross sectional view along line 3B - 3B of suture 30 in Figure 3A and shows with more particulanty angle Y, namely the radial 120 degree arrangement of barbs 35 with respect to barbs 37, barbs 37 with respect to barbs 39, and barbs 39 with respect to barbs 35
As illustrated by the stippling, first barb 35 of barbs 35, because of the staggenng, is closer to pointed end 34 (not shown in Figure 3B), and thus, seems to be larger than farther away first barb 3 7 of barbs 37 Also, first barb 37 of barbs 37, due to the staggenng, is closer to pointed end 34 (not shown in Figure 3B), and thus, seems to be larger than even farther away first barb 39 of barbs 39 A transverse plane that is perpendicular to suture body 32 and that intersects the base of one barb 35 of barbs 35 does not intersect the base of any barb 37 of barbs 37 Likewise, a transverse plane that is perpendicular to suture body 32 and that intersects the base of one barb 37 of barbs 37 does not intersect the base of any barb 39 of barbs 39 Similarly, a transverse plane that is perpendicular to suture body 32 and that
For the other half of the length of suture 40 axially spaced barbs 48 are radially arranged about 120 degrees from and staggered with respect to axially spaced barbs 50, which are radially arranged about 120 degrees from and staggered with respect to axially spaced barbs 52 Consequently, axially spaced barbs 52 are also arranged about 120 degrees from and staggered with respect to axially spaced barbs 48 Thus, another portion of suture 40 has all of baibs 48, 50, 52 facing in the same direction toward pointed end 46
As a result of the radial 120 degree arrangement, first set of barbs 47,48 define substantially the same one plane, second set of barbs 49, 50 define substantially another same one plane, and third set of barbs 51, 52 define substantially still another same one plane
Figure 4B, which is a cross sectional view along line 4B - 4B of suture 40 in Figure 4A, shows more clearly angle Y, namely the radial 120 arrangement with greater specificity As illustrated by the stipplmg, first barb 47 of barbs 47, on account of the staggenng, is closer to pointed end 44 (not shown in Figure 4B), and thus, appears larger than farther away first barb 49 of barbs 49 Also because of the staggenng, first barb 49 of barbs 49 is closer to pointed end 44 (not shown in Figure 4B), and thus, appears larger than even farther away first barb 51 of barbs 51
A transverse plane that is perpendicular to suture body 42 and that intersects the base of one barb 47 of barbs 47 does not intersect the base of any barb 49 of barbs 49 Likewise, a transverse plane that is perpendicular to suture body 32 and that intersects the base of one barb 49 of barbs 49 does not intersect the base of any barb 51 of barbs 51 Similarly, a transverse plane that is perpendicular to suture body 42 and that intersects the base of one barb 51 of barbs 51 does not intersect the base of any barb 47 of barbs 47 Also, a transverse plane that is perpendicular to suture body 42 and that intersects the base of one barb 48 of barbs 48 does not intersect the base of any barb 50 of barbs 50 Likewise, a transverse plane that is perpendicular to suture body 32 and that intersects the base of one barb 50 of barbs 50 does not intersect the base of any barb 52 of barbs 52 Similarly, a transverse plane that is perpendicular to suture body 42 and that intersects the base of one barb 52 of barbs 52 does not intersect the base of any barb 48 of barbs 48
Suture 40 may be made with the same cutting machine as suture 1, such as the cutting device descnbed in the above-noted Senal No 09/943,733 to Genova et al, except with the following change in blade direction
For firsl set of bi-directional barbs 47, 48, after the suture filament is placed and held in the vise, the blades splice with a first cutting action into approximately half of the length of the suture filament to create barbs 47 facing in one direction toward pointed end 44 Then,
the blades are rotated 180 degrees so that they are now disposed in the opposite direction and over the uncut half of the length The blades then are allowed to splice into the other half of the length of the suture filament with a second cutting action to create barbs 48 facing in the opposite direction toward pointed end 46
Next, the blades are offset longitudinally (to create the staggering) for about half the longitudinal distance between two of barbs 47, and also the suture filament is rotated about 120 degrees on the vise, which is equipped to accommodate first set of bi-directional barbs 47,48 that are already cut Then, for second set of bi-directional barbs 49, 50, the blades splice with a first cutting action into approximately half of the length of the suture filament to create barbs 50 facing in one direction toward pointed end 46 The first cutting action is followed by rotating the blades 180 degrees so that they are now disposed in the opposite direction and over the uncut half of the suture filament They then splice into the other half of the length of the suture filament with a second cutting action to create barbs 49 facing in the opposite dnection toward pointed end 44
Then, the blades are again offset longitudinally (to create the staggering) for about half the longitudinal distance between two of barbs 47 Additionally, the suture filament again is rotated about 120 degrees on the vise, which is equipped to accommodate already cut first set of br directional barbs 47,48 and already cut second set of bi directional barbs 49, 50 Following the longitudinal movement and rotation, the third set of b1 directional barbs 51,52 are made by having the blades splice with a first cutting action into approximately half of the length of the suture filament to create barbs 51 facing in one direction toward pointed end 44 The first cutting action is followed by rotating the blades 180 degrees so that they are now disposed in the opposite direction and over the uncut half of the suture filament They next splice into the other half of the length of the suture filament with a second cutting action to create barbs 52 facing in the opposite direction toward pointed end 46
Preferably, each successive barb is escarped at a position about 120 degrees around suture body 42 from the preceding barb and does not overlap with any other barb
In an alternative embodiment (not shown) for bi-directional suture 40, the portion of suture 40 having barbs 47, 49, 51 may have them facing toward pointed end 46 and the portion of sutuie 40 having barbs 48, 50, 52 may have them facing toward pointed end 44 With this vanation, the barbed suture would be inserted into tissue with an insertion device, such as that shown in the above-noted U S Patent No 5,342,376 to Ruff Additionally, it is noted that, if desired, barbs may be escarped so that there may be two portions with barbs facing one end and one portion with barbs facing the other end, or two portions with barbs
tacmg one end and two portions with barbs facing the other end, and so on (not shown), and
thus, if a portion of barbs is not facing the suture end that those barbs are adjacent, then, the barbed suture would be inserted into tissue with an insertion device
An advantage of a barbed suture with a radial 120 degree arrangement is that the barbs exert force in three distinct planes that compliment each other, resulting in maximization of the retention force of the suture overall As noted above, the staggering enhances anchoring performance
Turning now to Figure 5A, shown is another embodiment of the present invention, which is generally designated at suture 60, with radial spacing that is in a twist cut multiple spiral Suture 60 includes elongated body 62 of generally circular cross section Elongated body 62 terminates in pointed end 64 for penetrating tissue Also, it is contemplated that end 64 may comprise a surgical needle (not shown) for insertion into tissue Furthermore, suture 60 includes plurality of closely spaced barbs 67 arranged in a twist cut multiple spiral pattern around body 62 and facing in the same direction toward pointed end 64
Figure 5B is a cross sectional view along line 5B - 5B of suture 60 in Figure 5A Due to the twist cut multiple spiral disposition, each respective barb 67 seems to be smaller and smaller as each is farther and farther away from pointed end 64 (not shown in Figure 5B), the illusion of size difference being illustrated by the stippling
Suture 60 may be constructed with a similar cutting machine as that used for making suture 1, such as the cutting device described in the above-noted Serial No 09/943,733 to Genova et al With a twist cutting method, barbs 67 may be produced in multiple spirals that preferably are created at the same time as the suture filament is held stationary, instead of being rotated, when the cutting takes place
More particularly, a suture filament that is about 7 inches (about 178 mm) in length, is longitudinally twisted for a portion of the suture length, such as 39 times for a portion that is about 4 5 inches (about 114 mm) of the suture length Thus, an end is secured, and the other end is grasped and rotated 360 degrees, 39 times, so the portion of the suture filament is twisted when the suture is then placed and held in the vise
Twisting preferably is performed 28 to 50 times, and may be performed more or less, such as 19 to 70 times Suitably, twisting may be from about 2 to about 17 twists per inch, or about 3 to about 15 twists per inch, or about 5 to about 13 twists per inch (per inch being per 25 4 mm)
Next, the blades, after having been adjusted to a predetermined length, simultaneously splice into the suture filament The cutting action makes cuts to create barbs 67 so that all are
facing in the same direction toward pointed end 64 After twist cut multiple spiral barbed suture 60 is released from the vice and untwisted, barbs 67 are disposed in multiple spirals on suture 60
Turning now to Figure 6A, shown is another embodiment of the present invention, which is generally designated at suture 70 Suture 70 is of a twist cut multiple spiral disposition and thus is similar to suture 60, except that suture 70 is bi-directional Suture 70 includes elongated body 72 that is generally circular in cross section and that terminates in first and second pointed ends 74, 76 for penetrating tissue It is contemplated that one or both of ends 74, 76 may compose a surgical needle (not shown) for insertion into tissue
Suture 70 further includes plurality of closely spaced barbs 77, 78 arranged in two respective spiral patterns, each being a multiple spiral around body 72 Barbs 77, 78 are disposed on middle portion MP that is approximately 3 inches (approximately 76 mm) of suture 70, with each end portion EP of suture 70 being barb-free More particularly, plurality of barbs 77 are arranged in a multiple spiral pattern with all barbs 77 facing toward pointed end 74 for a part (about half) of middle portion MP along the length of suture 70 Similarly, plurality of barbs 78 are arranged in a multiple spiral pattern with all barbs 78 facing toward pointed end 76 for another part (the other approximate half) of middle potion MP along the length of suture 70
Figure 6B is a cross sectional view along line 6B - 6B of suture 60 in Figure 6A Due to the multiple spiral configuration, each respective barb 77 seems to be smaller and smaller as each is farther and farther away from pointed end 74 (not shown in Figure 6B), as illustrated by the stippling
Suture 70 may be made with the same cutting machine as suture 60, such as the cutting device described in the above-noted Serial No 09/943,733 to Genova et al, but with the following change in blade direction Using the twist cutting method, barbs 77 may be produced in multiple spirals that preferably are created at the same time, and then after the direction change for the blades, barbs 78 may be produced m multiple spirals that preferably are created at the same time Thus during the cutting, the suture filament is held stationary instead of being rotated
More specifically, a section of about 4 5 inches (about 114 mm) in length of a suture filament is twisted, such as 39 times for a suture about 7 inches (about 178 mm) in length Thus, an end is secured, and the other end is grasped and rotated 360 degrees, 39 times, so the twisted section of the suture filament has about 8 2/3 twists per inch (per 25 4 mm) when the suture filament is then is placed and held in the vise
Twisting preferably is performed 28 to 50 times, and may be performed more or less, such as 19 to 70 times Suitably, twisting may be from about 2 to about 17 twists per inch, or about 3 to about 15 twists per inch, or about 5 to about 13 twists per inch (per inch being per 25 4 mm)
Next, the blades, after having been adjusted to a predetermined length, splice into approximately half of the approximately 3 inch (approximately 76 mm) length of middle portion MP of the approximately 4 5 inch (approximately 114 mm) twisted section of the suture filament in a first cutting action with the blades making cuts to create barbs 77 so that all are facing in one direction toward pointed end 74 Depending on how many blades there are on the cutting machine and how many barbs 77 are desired, there may be one cutting motion to cut all barbs 77 simultaneously, or there may be repeated cutting motions until the desired number of barbs 77 are escarped into a portion of the suture filament
Then, the blades are rotated 180 degrees so that they are now disposed in the opposite direction and ovei the other half of the approximately 3 inch (approximately 76 mm) length of middle portion MP of the approximately 4 5 inch (approximately 114 mm) twisted section of the suture filament The blades are then allowed to splice into the other half in a second cutting action with the blades making cuts to create barbs 78 so that all are facing in the opposite direction toward pointed end 76 Depending on how many blades there are on the cutting machine and how many barbs 78 are desired, there may be one cutting motion to cut all barbs 78 simultaneously, or there may be repeated cutting motions until the desired number of barb* 78 are escarped into a portion of the suture filament
When twist cut multiple spiral barbed suture 70 is released from the vise and untwisted, the first cuts and the second cuts result m barbs 77,78 being m two respective multiple spiral patterns on two respective portions of suture 70, the two respective portions defining middle portion MP of about 3 inches (about 76 mm) in length
More partu ularly, several twist cut multiple spiral, barbed sutures were manufactured from a monofilament having a diameter of about 0 018 inch (about 0 457 mm) and spun from polydioxanone (which is a synthetic absorbable suture material) A diameter of about 0018 inch (about 0 457 mm) is slightly larger than the size 0 synthetic absorbable suture, which has a diameter range from about 0 35 mm to about 0 399 mm m accordance with the specifications of the United States Pharmacopoeia (USP)
Each suture contained a total of 78 barbs introduced in two respective multiple spiral patterns around I he circumference of the suture Since the barbed suture was bi-directional, the barbs were divided into a left group with 39 barbs disposed on a first portion of the suture
and a right group with 39 barbs on a second portion of the suture, each group opposing the direction of the other group from the approximate middle of the suture The specific cutting machine employed had 13 blades Thus, for each group of 39 barbs, there were 3 cutting motions (3 x 15 - 39), with the blades being offset with a guide for each of the 3 cutting motions
Each suture was about 7 inches (about 178 mm) long The middle portion MP was about 3 inches (about 76 mm) long and contained the 78 barbs that were escarped into the suture filament Extending beyond the 3 inch (76 mm) barbed middle portion MP were two unbarbed end portions EP of the suture that were each about 2 inches (about 51 mm) long Depending on the suturing technique one or both ends of the barbed suture may be sufficiently pointed and rigid for insertion into tissue, or may comprise a straight or curved surgical needle
The strength of the twist cut 7 inch (178 mm) barbed sutures was tested by two methods One method was a straight pull tensile strength test with a Universal Tester and the other method was an in vivo performance test with dogs
For the straight pull tensile strength measurement, testing was performed using a Test Resources Universal Tester, Model 200Q The average reading of 10 repeated measurements made for each kind of suture was recorded for the barbed sutures and for the comparison unbarbed suture s
Comparison unbarbed sutures were polydioxanone monofilaments (a synthetic absorbable suture material) of various suture diameters of about 0 018 inch (about 0 457 mm), about 0 015 inch (about 0 381 mm), and about 0 0115 inch (about 0 292 mm), which are respectively slightly larger than the United States Pharmacopoeia sizes 0, 2 0, and 3-0 for synthetic absorbable sutures In accordance with United States Pharmacopoeia specifications for synthetic ab orbable sutures, size 0 has a diameter range of about 0 35 mm to about 0 399 mm, size 2-0 has a diameter range of about 0 30 mm to about 0 339 mm, and size 3-0 has a diameter range of about 0 20 mm to about 0 249 mm
Each baibed suture was gnpped at each end by being held with cork gasket padding in two respective serrated jaws, whereas each unbarbed suture was gnpped at each end by being wrapped around two respective capstan roller gnps Capstan rollers were used for holding the unbarbed sulures to avoid stress and distension
The portion of each suture specimen between the two gnpped places was about 5 inches (about 126 mm) m length, which, in the case of barbed sutures, contained the entire 3 inches (76 mm) of the barbed middle portion
Each specimen was pulled longitudinally at a rate of about 10 inches (about 254 mm) per minute until breakage occurred The peak load was recorded as the straight pull tensile strength
The results are summarized in Table 6A below, and the far right column denotes the USP knot pull test minimum requirements for conventional (unbarbed) sutures made from a synthetic absorbable material
Table 6A (Tensile Strength)

(Table Removed)

As can be seen, escarpment of barbs into the size 0 polydioxanone monofilament reduced the straight pull tensile strength by approximately 60% as compared to the conventional unbarbed size 0 polydioxanone monofilament (7 03 pounds = 40% of 17 72 pounds)
Howeve r, the straight pull tensile strength of 7 03 pounds at breakage for the size 0 polydioxanone barbed suture (which, due to the escarpment of the barbs, has an effective diameter that is smaller than the diameter of the conventional unbarbed size 0 polydioxanone suture) compared favorably with the minimum USP knot pull requirement of 8 60 pounds for the size 0 polydioxanone conventional unbarbed suture
Additional straight pull tensile strength tests were performed on additional size 0 polydioxanone barbed sutures, as discussed below in Tables 7K-7Z, in connection with Figures 7A and 7B
For the in vivo performance, 3 mongrel dogs, each about 14 kg, were used On each dog, 7 incisions were made at the thorax (twice), thigh (twice), flank, ventral midline, and paramedian, each of the 7 incisions having 1, 2, or 3 closure sites The length of each
incision ranged from about 0 5 inch (about 12 5 mm) to about 4 inches (about 101 mm) and me depth of eac h incision was from the superficial dermis to the peritoneum
Using the barbed sutures (all made from size 0 polydioxanone monofilament), 24 of the sites were closed For companson, the remaining sites were closed with vanous diameter sizes of conventional unbarbed sutures (1 site with size 2-0 silk braided filament, 6 sites with size 2-0 nylon monofilament, and 7 sites with size 3-0 polydioxanone monofilament), which were knotted All closing of sites was performed according to a randomized scheme
The dogs were monitored daily, and then subjected to euthanasia at 14 days At the time of death, the incisions were evaluated macroscopically With regard to vanous tissues, incision sizes, and locations on the dogs, all sites apposed with the size 0 polydioxanone barbed sutures stayed closed and appeared to be healing normally throughout the 14 day observation penod No dehiscence occuned
The site apposed with the conventional unbarbed silk sutures and the sites apposed with the conventional unbarbed polydioxanone sutures also healed will without complications No dehiscence occurred
For the 6 topical skin sites closed with the size 2-0 nylon monofilament conventional unbarbed sutures, 3 sites exhibited partial or complete suture loss, apparently due to self mutilation by the dogs Knots in the conventional sutures possibly caused discomfort by creating localized pressure, and animals cannot understand that they should not manipulate the sutures Thus, barbed sutures should help obviate the problem of an animal manipulating and pulling out the sutures
In summary, the in vivo performance of the size 0 polydioxanone barbed sutures was efficacious when compared to the size 2-0 silk braided filament unbarbed sutures, the size 2 0 nylon monofilament unbarbed sutures, and the size 3-0 polydioxanone monofilament unbarbed sutures
In an alternative embodiment (not shown) for bi-directional twist cut, multiple spiral suture 70, the portion of suture 70 on which is disposed barbs 77 may have barbs 77 facing toward pointed end 76 and the portion of suture 70 on which is disposed barbs 78 may have barbs 78 facing toward pointed end 74 With this vanation, the barbed suture would be inserted into tissue with an insertion device, such as that shown in the above-noted U S Patent No 5,342,376 to Ruff Also if desired, it is noted that barbs may be escarped so that there may be 2 portions with barbs facing an end and 1 portion with barbs facing the other end, or 2 portions with barbs facing an end and 2 portions with barbs facing the other end, and so on (not hown), and thus, if a portion of barbs is not facing the suture end to which
those barbs are adjacent, then, the barbed suture would be inserted into tissue with an insertion device
An advantage of a barbed suture having a twist cut, multiple spiral disposition is that such a barbed suture affords better wound holding capability as compared to the 120 degree spaced barbed suture The reason is that the twist cut, multiple spiral pattern results in groups of barbs that complement successive and preceding groups of barbs, which tends to provide improved anchonng when the suture is in tissue This feature is especially useful for tissue such as fat tissue, which has fewer connective fibers compared with other types of tissues, so that greater suture retention force is desirable
With reference now to Figure 7A, shown is a sectional side view of barbed suture 80 Barbed suture 80 has plurality of closely spaced barbs 81 on elongated suture body 82 of generally circular cross section Each barb 81 has barb tip 85 Shown are suture longitudinal axis A, suture diameter SD, barb length L, barb cut depth D, barb cut angle 0, cut distance P, spirahty angle a, cut-out depression CD, and tip T of cut-out depression CD
Figure 7B is the sectional side view as illustrated in Figure 7A, but rotated and clamped to align the barbs for measurement of the cut distance P between barbs 81
Barbed suture 80 is a twist cut, multiple spiral, b1 directional barbed suture, like suture 70 in Figure 6A, but illustrated as an enlarged section in order to show more detail with respect to the configuration of barbs 81 vis-a-vis suture longitudinal axis A, suture diameter SD, barb length L, barb cut depth D, barb cut angle 0, cut distance P, spirahty angle a, cut-out depression CD, and terminus T of cut-out depression CD
More specifically, several twist cut, multiple spiral, barbed sutures were manufactured from monofilament spun from polydioxanone and having a diameter of about 0 018 inch (about 0 457 mm, which is slightly more than the USP requirement for a size 0 synthetic absorbable suture) Each suture contained 78 barbs introduced in 2 separate multiple spiral patterns around the circumference of the suture Since the barbs were bi-directional, they were divided into a left group with 39 barbs and a right group with 39 barbs, each group opposing the direction of the other group from the approximate middle of the suture Each suture was about 7 inches (about 178 mm) long The middle portion was about 3 inches (about 76 mm) of the suture and contained the 78 barbs that were escarped into the suture filament Extending beyond the 3 inch (76 mm) barbed middle portion toward each suture end were two unbarbed end portions of the suture filament that were each about 2 inches (about 51 mm) long Depending on the stitching technique, one or both ends of the barbed
suture may be suificiently pointed and rigid for insertion into tissue or may comprise a straight or curved needle
In ordei to characterize the configuration of barbs 81, an Optem Zoom 100 custom microscope with both ring and back lighting was used together with a CCD brand video camera m order to measure selected barbs 81 at x21 5 magnification from each of the left and nght groups
The average was calculated for 10 repeated measurements (5 from the left group of barbs and 5 from the nght group of barbs on the same suture) that were made for each of cut angle 9 and cut depth D Barb cut angle 0 was measured from the surface of the cut to the outer surface ol barbed suture 80 Barb cut depth D was measured along a perpendicular from the outer surface of barbed suture 80 toward longitudinal axis A of barbed suture 80 The measurements enabled cut length L to be calculated using the following formula
L = D/{Sm(180-8)}
Also, angle a of spirahty was measured microscopically on vanous barbed sutures 80 as follows When the twisted suture filament is gnpped by the vise dunng cutting of barbs 81, the vise leaves a very light mark designated as line M impressed on the suture filament Thus, line M will be parallel to the longitudinal axis of the vise while the twisted suture filament is being held in the vise If the vise does not leave a light mark on the suture filament, then line M can be determined in that it is parallel to a line connecting the two respective terminus T of the two successive cut-out depressions CD left in suture body 82 from the escarpment of two successive barbs 81 After cutting of barbs 81, when barbed suture 80 is released from the vise and untwisted so that suture 80 hes free, then line M spirals on suture body 82 around barbed suture 80, forming angle a of spirahty
Specifically for measunng spirahty angle a, the Optem Zoom 100 custom microscope was set with nng lighting at 60 and back lighting at coarse 12 and fine 10 Also, imaging analysis system software was used Spirahty angle a was then measured between the outer surface of the barbed suture and line M The average was calculated for 10 repeated measurements (5 from the left group of barbs and 5 from the nght group of barbs on the same suture)
Then, barbed suture 80 was mounted in a twisting device with one end of suture 80 clamped m a fixed position The other end of suture 80 was rotated to insert twist until barbs
81 were aligned Next on barbed suture 80, longitudinal cut distance P between two adjacent barbs 81 was measured microscopically between the two respective terminus T of the two successive cut-out depressions CD left m suture body 82 from the escarpment of two successive barbs 81 The average was calculated for 10 repeated measurements (5 from the left group of barbs and 5 from the right group of barbs on the same suture)
The results are summarized in the following Tables 7 A, 7B, 7C, and 7D
Table 7A (size 0 barbed suture)
Ratio of D, L, or
P over Suture
Measurement Units Left Right Diameter (0 457 mm)
cut angle  degrees 156 + 2 157 + 1 not applicable
cut depth D mm 0 15 ±0 02 0 16 ±0 04 0 35
cutlengthL mm 036±003 040±0 10 0 87
cut distance P mm 0 90 + 017 088 + 015 192
Table 7B (size 0 barbed suture)
Ratio of D, L, or
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457 mm)
cut angle  degrees 151 1642 not applicable
cut depth D mm 0 215 0 027 0 47
cutlength L mm 0 446 0 042 0 97
cut distance P mm 0 962 0 073 2 1
spirahty angle α degrees 20 833 1 602 not applicable
Table 7C (size 0 barbed suture)
Ratio of D, L, or
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457 mm)
cut angle  degrees 154 2 870 not applicable
cut depth D mm 0 205 0 033 0 45

cut length L mm 0 469 0 044 103
'cut distance P mm 0 975 0103 2 13
spirahty angle α degrees 19 333 1506 not applicable
Table 7D (size 0 barbed suture)
Ratio of D, L. or
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457 mm-)
cut angle  degrees 155 2 390 not applicable
cut depth D mm 0 186 0 026 0 41
cut length L mm 0 437 0 039 0 96
cut distance P mm 0 966 0 071 2 11
spirahty angle α degrees 18 833 2 137 not applicable
Also, some additional measurements of angle a were performed on a few additional bi-directional twist cut, multiple spiral barbed sutures with a diameter of about 0 018 inch (about 0 457 mm, slightly more than the USP requirement for a size 0 synthetic absorbable suture) The mean average was 16 87 and the standard deviation was + 0 85
Additionally, measurements of barb cut angle 0, barb length L, barb cut depth D and cut distance P were performed on 3 additional bi-directional twist cut, multiple spiral barbed sutures like sutures 80, but having a diameter of about 0 0115 inch (about 0 292 mm which is slightly more than the USP requirement for a size 3-0 synthetic absorbable suture), and measurements of spirahty angle a were performed on 2 of these 3 additional barbed sutures Also, measurements of barb cut angle 9, barb length L, barb cut depth D, cut distance P, and spirahty angle a were performed on 3 additional bi-directional twist cut, multiple spiral barbed sutures like sutures 80, but with a diameter of about 0 015 inch (about 0 381 mm, which is slightly more than the USP requirement for a size 2-0 synthetic absorbable suture) The results are summarized in the following Tables 7E, 7F, 7G, 7H, 71, and 7J
Table 7E (size 3-0 barbed suture)
Ratio of D, L, or
P over Suture
Measurement Units Average Standard Deviation Diameter (0 292 mm)
cut angle  degrees 166 1651 not applicable
cut depth D mm 0 107 0 007 0 37
cut length L mm 0 443 0 042 152
cut distance P mm 0 956 0 079 3 27
spirahty angle α degrees not tested not applicable not applicable
Table 7F (size 3-0 barbed suture)
Ratio of D, L, or
P over Suture
Measurement Units Average Standard Deviation Diameter (0 292 mm)
cut angle  degrees 164 2 055 not applicable
tut depth D mm 0 106 0 006 0 36
cut length L mm 0 395 0 042 135
cut distance P mm 0 959 0 074 3 28
spirahty angle α degrees 7 329 0 547 not applicable
Table 7G (size 3-0 barbed suture)
Ratio of D, L, or
P over Suture
Measurement Units Average Standard Deviation Diameter (0 292 mm)
cut angle  degrees 165 1031 not applicable
cut depth D mm 0 104 0 009 0 36
cut length L mm 0 390 0 035 134
cut distance P mm 0 975 0103 3 34
spirahty angle α degrees 7 258 0 636 not applicable
Table 7H (size 2-0 barbed suture)
Ratio of D, L, or
P over Suture
Measurement Units Average Standard Deviation Diameter (0 381 mm)
cut angle  degrees 160 2 1320 not applicable
cut depth D mm 0 152 0 019 0 40
cut length L mm 0 449 0 057 1 18
cut distance P mm 0 944 0098 2 48
spirahty angle α degrees 9 40 1606 not applicable
Table 71 (size 2-0 barbed suture)
Ratio of D, L, or
P over Suture
Measurement Units Average Standard Deviation Diameter (0 381 mm)
cut angle  degrees 1610 1707 not applicable
cut depth D mm 0 158 0 014 0 41
cut length L mm 0 489 0 054 128
cut distance P mm 0 962 0 054 2 52
spirahty angle α degrees 7 96 1075 not applicable
Table 7J (size 2-0 barbed suture)
Ratio of D, L, or
P over Suture
Measurement Units Average Standard Deviation Diameter (0 381 mm)
cut angle  degrees 1610 1506 not applicable
cut depth D mm 0 154 0 017 0 40
cut length L mm 0 474 0 058 1 24
cut distance P mm 0 973 0 068 2 55
spirahty angle α degrees 6 53 1 755 not applicable
Additional measurements were performed on several other twist cut, multiple spiral, barbed sutures manufactured from monofilament spun from polydioxanone and having a diameter of about 0 018 inch (about 0 457 mm, which is slightly more than the USP requirement for a size 0 synthetic absorbable suture) and thus similar to the above described tested barbed sutures, except that these other barbed sutures were cut with a different cutting machine, namely a machine with one blade that moved longitudinally along the twisted filament between cutting strokes and that was controlled with a computer to make the vanous cuts tor the escarpment of the barbs These other barbed sutures were also tested for straight pull tensile strength and for chamois cloth closure strength (A discussion of how chamois cloth closure strength is performed can be seen below in connection with Figures 13A and

13B ) The results for these other barbed sutures are summarized in the following Tables 7K

Table 7K (size 0 barbed suture)
Ratio of D.L.
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457
mm)
cut angle  degrees 152 6 0 718 not applicable
cut depth D mm 0 221 0 011 048
cut length L mm 0 479 0 022 105
cut distance P mm 0 784 0 015 171
spirahty angle α degrees 12 9 0 453 not applicable
Table 7L (size 0 barbed suture)
Ratio of D.L,
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457 mm)
cut angle  degrees 152 4 0 947 not applicable
cut depth D mm 0 216 0 014 0 47
cut length L mm 0 465 0 024 102
cut distance P mm 0 774 0 015 169
spirahty angle α degrees 13 2 0 349 not applicable
Table 7M (size 0 barbed suture)
Ratio of D.L.
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457 mm)
cut angle G degrees 152 3 0 576 not applicable
cut depth D mm 0 227 0 015 0 50
cut length L mm 0 489 0 034 107
cut distance P mm 0 796 0 018 174
spirahty angle a degrees 13 1 0 193 not applicable

Table 7N (size 0 barbed suture)
Ratio of D,L,
P over Suture
MeasurementUnits Average Standard Deviation Diameter (0 457
mm)
cut angle  degrees 152 8 0 612 not applicable
cut depth D mm 0 207 0 007 0 45
cut length L mm 0 453 0 016 0 99
cut distance P mm 0 798 0 017 175
spirahty angle α degrees 13 6 0 560 not applicable
Table 70 (size 0 barbed suture)
Ratio of D.L.
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457
mm)
cut angle  degrees 152 9 0 549 not applicable
cut depth D mm 0 188 0 016 0 41
cut length L mm 0 413 0 030 0 90
cut distance P mm 0 787 0 024 172
spirahty angle α degrees 13 8 0 270 not applicable
Table 7P (size 0 barbed suture)
Ratio of D.L.
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457
mm)
cut angle  degrees 153 1 0 655 not applicable
cut depth D mm 0 204 0007 0 45
cut length L mm 0 451 0 019 0 99
cut distance P mm 0 792 0 018 173
spirahty angle α degrees 13 6 0 410 not applicable
Table 70 (size 0 barbed suture)
Ratio of D,L, P over Suture
Measurement Units Average Standard Deviation Diameter (0 457
mm)
cut angle  degrees 163 1 0 505 not applicable
cut depth D mm 0 245 0 013 0 54
cut length L mm 0 842 0 045 1 84
cut distance P mm 0 774 0 009 169
spirahty angle α degrees 10 8 0 449 not applicable
Table 7R (size 0 barbed suture)
Ratio of D,L, P over Suture
Measurement Units Average Standard Deviation Diameter (0 457
mm)
cut angle  degrees 161 1 1 126 not applicable
cut depth D mm 0 233 0017 0 51
cut length L mm 0 721 0 035 1 58
cut distance P mm 0 773 0 010 169
spirahty angle α degrees 12 6 0 189 not applicable
Table 7S (size 0 barbed suture)
Ratio of D. L,
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457
mm)
cut angle  degrees 160 9 0 708 not applicable
cut depth D mm 0 240 0 014 0 52
cut length L mm 0 734 0 037 161
cut distance P mm 0 774 0 009 169
spirality angle α degrees 13 6 0 312 not applicable
Table 7T (size 0 barbed suture)
Ratio of D, L,
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457
mm)
cut angle  degrees 154 6 1434 not applicable
cut depth D mm 0 210 0 009 0 46
cut length L mm 0 492 0 026 108
cut distance P mm 0 538 0 011 1 18
spirality angle α degrees 12 3 0 223 not applicable
Table 7U (size 0 barbed suture)
Ratio of D.L.
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457
mm)
cut angle  degrees 152 9 0 809 not applicable
cut depth D mm 0 212 0 014 0 46
cut length L mm 0 464 0 026 101
cut distance P mm 0 530 0 015 1 16
spirality angle α degrees 13 7 0 411 not applicable
Table 7V (size 0 barbed suture)
Ratio of D.L.
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457
mm)
cut angle  degrees 153 4 0 903 not applicable
cut depth D mm 0 221 0 010 0 48
cut length L mm 0 495 0 023 108
cut distance P mm 0 537 0 012 1 17
spirahty angle α degrees 13 9 0 605 not applicable
Table 7W (size 0 barbed suture)
Ratio of D.L,
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457
mm)
cut angle  degrees 155 2 0 829 not applicable
cut depth D mm 0 202 0 008 0 44
cut length L mm 0 483 0 017 106
cut distance P mm 0 789 0 031 173
spirality angle α degrees 12 6 0 328 not applicable
Table 7X (size 0 barbed suture)
Ratio of D.L, P over Suture
Measurement Units Average Standard Deviation Diameter (0 457
mm)
cut angle  degrees 155 5 0 799 not applicable
cut depth D mm 0 200 0 010 0 44
cut length L mm 0 484 0 027 106
cut distance P mm 0 798 0 017 175
spirahty angle α degrees 118 0 362 not applicable
Table 7Y (size 0 barbed suture)
Ratio of D,L,
P over Suture
Measurement Units Average Standard Deviation Diameter (0 457
mm)
cut angle  degrees 155 4 0 560 not applicable
cut depth D mm 0 196 0 008 043
cut length L mm 0 471 0 017 103
cut distance P mm 0 799 0 019 175
5 spirahty angle α degrees 118 0 496 not applicable
Table 7Z
0 Barbed Suture Straight Pull Strength Chamois Cloth Closure Strength
(pounds) (pounds to rupture)
Sample 1 7 29 1123
(Tables 7K-7M)
Sample 2 8 73 1214
5 (Tables 7N - 7P)
Sample 3 8 5 9 22
(Tables 7Q-7S)
Sample 4 5 92 9 27
(Tables 7T-7V)
3 Sample 5 7 69 9 97
(Tables 7W-7Y)
filament may be jeopardized, which could lead to a tendency of the barbs to peel back and also to a decrease in suture tensile strength
Generally, a suitable ratio of cut distance P to barbed suture diameter SD ranges from about 0 1 to about 6, more preferably from about 0 5 to about 4 5, even more preferably from about 1 0 to about 3 5 Very suitable barbed sutures may have a ratio of cut distance P to barbed suture diameter SD from about 1 5 down to about 0 2, whereby cut distance P may be as low as about 0 1, particularly for the overlapping barb embodiment, which is discussed in more detail below vis-a-vis Figures 12A, 12B, 12C, and 12D
Additionally, spirahty angle a formed between line M and the longitudinal direction of the elongated suture body for a twist cut, multiple spiral barbed suture typically would range from about 5 degrees to about 25 degrees, more preferably from about 7 degrees to about 21 degrees The most preferred angle a for all barbs on a twist cut, multiple spiral barbed suture is about 10° to about 18°
Turning now to Figure 8, shown is suture 90, which is another embodiment of the present invention Suture 90 includes elongated body 92 that is generally circular in cross section Elongated body 92 terminates in first and second pointed ends 94, 96 for penetrating tissue It is contemplated that one or both ends 94, 96 may comprise a surgical needle (not shown) for insertion into tissue Additionally, suture 90 includes plurality of closely spaced barbs 97 arranged in a random disposition
Suture 90 may be made with the same cutting machine as the above-discussed sutures, such as the cutting device described in the above-noted Serial No 09/943,733 to Genova et al With combinations of the above-descnbed methods for making the 180 degree disposition (sutures 1,10), the 120 degree disposition (sutures 30, 40), and/or the twist cut multiple spiral disposition (sutures 60, 70, 80), barbed suture 90 with a very random barb disposition is obtained The advantage of the random disposition is that the many barb angles provide superior anchoring m tissues and thus afford superior wound holding properties With the random disposition, the barbed suture would be inserted into tissue with an insertion device, such as that shown in the above-noted U S Patent No 5,342,376 to Ruff
With regard to Figure 9, shown is a sectional side view of barbed suture 100, which is another embodiment of the present invention Suture 100 includes elongated suture body 102 of generally circular cross section Also, suture body 102 has disposed on it a plurality of closely spaced barbs 107 Each barb 107 has a barb configuration such that barb underside 108 is serrated or corrugated One or both suture ends (not shown) are pointed for
penetrating tissue and it is contemplated that one or both may compnse a surgical needle (not shown) for insertion into tissue
Suture ] 00 may be made with the same cutting machine as the above-discussed sutures, such as the cutting device described in the above-noted Serial No 09/943,733 to Genova et al Barb 107 having serrated underside 108 is achieved by vibrating or oscillating the cutting blades of the cutting device when barbs are being escarped into the body of a monofilament It is intended that any of the barbed sutures of the present invention as described here may have barbs with a configuration that includes a serrated or corrugated underside
With relerence now to Figures 10A and 10B, depicted in Figure 10 A is a perspective view and depicted in Figure 10B is a top view of barbed suture 110, which is another embodiment of the present invention Suture 110 includes elongated suture body 112 of generally circular cross section Also, suture body 112 has disposed on it a plurality of closely spaced barbs 115 having barb tips 117 (one barb 115 is shown for purposes of brevity) Barb 115 has a configuration with an arcuate base 119 where barb 115 is attached to suture body 112 One or both suture ends (not shown) are pointed for penetrating tissue and it is contemplated that one or both may compnse a surgical needle (not shown) for insertion into tissue
Figures 10C and 10D are cross-sectional views respectively along line 10C - 10C and line 10D - 10D of Figure 10B Figure 10C and 10D further clanfy that barb 115 becomes narrower going from base 119 toward tip 117
Suture 110 may be made with the same cutting machine as the above discussed sutures, such as the cutting device descnbed m the above-noted Senal No 09/943,733 to Genova et al To achieve barb 115 having arcuate base 119, the cutting device is provided with cutting blades with ends that are correspondingly arcuate with respect to arcuate base 119
It is intended that any of the barbed sutures of the present invention as descnbed here may have barbs with a configuration that includes an arcuate base The arcuate base should enhance tissue anchonng as compared to a flat, linear base Regardless, it is not desired for the base to be circular or oval, which would result from conical shaped barbs, as that could decrease tissue anchonng
Shown m Figure 11 is a sectional side view of a barbed suture that is another embodiment of the present invention, and that is generally designated at 120 Suture 120 includes elongated body 122 that is generally circular in cross section Elongated body 122
terminates in end 124 End 124 is pointed for penetrating tissue and it is contemplated that end 124 may comprise a surgical needle (not shown) for insertion into tissue (The other end is not shown, and also may be pointed for penetrating tissue and may comprise a surgical needle for penetrating tissue )
Also, suture 120 includes plurality of closely spaced barbs 125, plurality of closely spaced barbs 127, and plurality of closely spaced barbs 129 Barbs 125 are relatively small in size with a relatively short barb length as compared to barbs 127, which are relatively medium m size with a relatively medium barb length, as compared to barbs 129, which are relatively large in size with a relatively long barb length
Suture 120 may be made with the same cutting machine as the above-described sutures were made, such as the cutting device described in the above-noted Serial No 09/94 3,733 to Genova et al By altering the amount of blade movement during cutting into a suture filament, then the barb cut length is made longer or shorter, as desired, to result in each of the three sets of barbs 125,127, and 129 being of a size different from the others, where the varying sizes are designed for various surgical applications The barb size may also vary m the transverse direction, whereby the barb base may be short, medium, or long, and regardless, the barb base typically is less than about lA of the suture diameter
For mstance, relatively larger barbs are desirable for joining fat and soft tissues, whereas relatively smaller barbs are desirable for joining fibrous tissues Use of a combination of large, medium, and/or small barbs on the same suture helps to ensure maximum anchoring properties when barb sizes are customized for each tissue layer Only two different si/ed sets of barbs (not shown) may be escarped into suture body 122, or additional sets of barbs (not shown) with four, five, six, or more different sized sets than three sizes as illustrated for sets of barbs 125,127, and 129 may be escarped into suture body 122 as desired, in accordance with the intended end use Also, although suture 120 is illustrated with the barbs being unidirectional, it is intended that barbed sutures with barbs having a configuration ol varying sizes in accordance with the invention also may be bi-directional barbed sutures or random barbed sutures or any of the other inventive barbed sutures described here
Figure 12A is a perspective view of another embodiment of the present invention, showing barbed suture 130 having elongated body 132 of generally circular cross section One or both suture ends (not shown) are pointed for penetrating tissue and it is contemplated that one or both ends may comprise a surgical needle (not shown) for insertion into tissue
Suture 130 further includes plurality of barbs 135 projecting from body 132 such that at least two longitudinally adjacent first and second barbs 135 are disposed on body 132 where first barb 135 overlaps second barb 135 if first and second barbs 135, which is readily apparent if barbs 135 are laid flat on body 132
Figure 12B is a perspective view of a portion of overlapping barbs 135 of the overlapping disposition barbed suture 130 of Figure 12A, and Figure 12C is a top plan view of Figure 12B Figure 12D is a cross-sectional view along l mg 12D - 12D of Figure 12C As can be more clearly seen from Figures 12B, 12C, and 12D, during escarpment of barbs 135, overlapping first barb 135 is escarped into part of topside TS of overlapped second barb 135, and so on Part of topside TS of overlapped second barb 135 becomes part of underside US of overlapping first barb 135
Thus, with the overlapping disposition, the barb cut distance between first barb 135 and second barb 135 may be shorter than the barb cut length of overlapped second barb 135, whereas, in general for barbed sutures, the barb cut distance between two barbs > the barb cut length Particularly for the overlapping barb disposition, very suitable barbed sutures may have a ratio of the barb cut distance to the barbed suture diameter from about 1 5 down to about 0 2, since the barb cut distance P may be as low as about 0 1 (See discussion of Figure 7 for comments vis a vis the barb cut length and the barb cut distance ) This overlapping disposition allows for closely packing many barbs 135 on body 132, and typically, barbs 135 are thin, as compared to when the barb cut distance between two barbs > the barb cut length
Also, although suture 130 is illustrated with barbs 135 being unidirectional, it is intended to include that suture 130 m accordance with the invention also may be a bidirectional barbed suture as described here
Figures 13 A, 13B, 13C, and 13D show various surgical needles, where a barbed suture is attached to each surgical needle In order to facilitate insertion into tissue, the surgical needles may be coated with a polymer, for instance, as described above vis-a-vis U S Patent No 5,258,013 to Granger et al
Figure 13A shows surgical needle Nl that is a straight elongated needle in the longitudinal direction and that is generally circular in cross section Surgical needle Nl has pointed tip TI for insertion into tissue and also has hole H1 Surgical needle Nl is illustrated as attached, such as by swaging, to barbed suture S1 Barbed suture S1 is a barbed suture including, but not limited to, any of the above-described barbed sutures Additionally, surgical needle N l has diameter Dl in the transverse direction, which is illustrated as a relatively thin diameter, such as about 0 02 inch (about 0 51 mm) As discussed above vis a
vis swaging, surgical needle Nl, after having suture SI inserted into hole HI, may be crimped by standard procedures about hole HI to hold suture Sim place for suturing tissue
Figure 13B shows surgical needle N2 that is a straight elongated needle in the longitudinal dnection and that is generally circular in cross section Surgical needle N2 has pointed tip T2 l or insertion into tissue and also has hole H2 Surgical needle N2 is illustrated as attached, such as by swaging, to barbed suture S2 Barbed suture S2 is a barbed suture including, but not limited to, any of the above-described barbed sutures Additionally, surgical needle N2 has diameter D2 in the transverse direction, which is illustrated as a suitably thin diameter, such as about 0 032 inch (about 0 81 mm), but not as thm as diameter Dl of surgical needle Nl As discussed above vis-a-vis swaging, surgical needle N2, after having suture S2 inserted into hole H2, may be crimped by standard procedures about hole H2 to hold suture S2 in place for use m suturing tissue
Figure 13C shows surgical needle N3 that is a curved elongated needle in the longitudinal direction and that is generally circular in cross section Surgical needle N3 has pointed tip T3 for insertion into tissue and also has hole H3 Surgical needle N3 is illustrated as attached, such as by swaging, to barbed suture S3 Barbed suture S3 is a barbed suture including, but not limited to, any of the above described barbed sutures Additionally surgical needle N3 has diameter D3 in the transverse direction, which is illustrated as a relatively thm diameter, such as about 0 02 inch (about 0 51 mm) As discussed above vis a-vis swaging, surgical needle N3, after having suture S3 inserted into hole H3, may be crimped by standard procedures about hole H3 to hold suture S3 in place for use in suturing tissue
Figure 13D shows surgical needle N4 that is a curved elongated needle in the longitudinal direction and that is generally circular in cross section Surgical needle N4 has pointed tip T4 for insertion into tissue and also has hole H4 Surgical needle N4 is illustrated as attached, such as by swaging, to barbed suture S4 Barbed suture S4 is a barbed suture including, but not limited to, any of the above-described barbed sutures Additionally, surgical needle N4 has diameter D4 in the transverse direction, which is illustrated as a suitably thm diameter, such as about 0 032 inch (about 0 81 mm), but not as thin as diameter D3 of surgical needle N3 As discussed above vis-a-vis swaging, surgical needle N4, after having suture S4 inserted into hole H4, may be cnmped by standard procedures about hole H4 to hold sutuie S4 m place for use in suturing tissue
Needle tips TI, T2, T3, and T4 are schematically illustrated as pointed, but, as is well known, surgical needles come with various kinds of pointed tips, such as taper point taper
cutting, ball point, cutting edge diamond point, thin line, and lancet point, and it is intended to include, but not be limited to, all such needle tips Taper point, taper cutting, and diamond point are preferred needle tips for surgical needles used with barbed sutures
As is well known in the art, needle diameter for surgical needles used with conventional (1 e , unbarbed) sutures is considered unimportant, and often very thick surgical needles are used with thin conventional sutures such that the ratio of surgical needle diameter to conventional suture diameter is 4 1 or even higher, such as 4 43 1
However, with the surgical needle/barbed suture combination of the present invention (for either a straight needle or a curved needle), the thinner that the surgical needle is, then the more preferable that the surgical needle/barbed suture is, with the desired needle diameter being thinner and thinner as it approaches the barbed suture diameter, and it is possible that the needle diameter may be even thinner than the barbed suture diameter
In geneial for the present invention, a relatively thin surgical needle attached to a barbed suture is more preferable for approximating tissue when stitching a wound closed than a relatively thick surgical needle threaded with a barbed suture The reason is that the relatively thin surgical needle attached to a barbed suture allows for greater engagement of barbs in tissue, and therefore provides better closure strength to the approximated tissue that has been sutured to prevent the opposing sides of the closed wound from pulling apart, as compared to the closure strength provided to approximated tissue that has been sutured with the relatively thick surgical needle
The most important feature for the combination of the surgical needle attached to the barbed suture is that the surgical needle diameter should be of sufficient width in order to make a hole or a channel in the end, such by drilling, to allow for insertion of the barbed suture into the hole or the channel Nevertheless, as the surgical needle diameter increases, the surgical needle is still suitable as long as the ratio of the surgical needle diameter to the barbed suture diameter is about 3 1 or less
Accordingly, a desirable ratio of surgical needle diameter to barbed suture diameter, for either a straight needle or a curved needle, is about 3 1 or less, more preferably about 2 1 or less, most preferably about 1 8 1 or less Furthermore, particularly if channel needles are employed, the ratio of surgical needle diameter to barbed suture diameter may be as low as about 1 1 or less, or even lower, for instance, about 0 9 1 or less, or about 08 1 or less, or as low as about 0 5 1 It will be appreciated by the person of ordinary skill in the art that care should be taken with extremely thin needles so as to ameliorate the possibility of localized weakness, which may compromise tissue insertion
Closure strength of thin surgical needles, both having a ratio of surgical needle diameter to barbed suture diameter suitable for the present invention, was tested as follows
Various pieces of chamois leather (manufactured by U S Chamois of Florida) having a thickness of about 0 6 in (about 15 2 mm) were cut with a wound having a length of about 1 25 inch (about 32 mm)
A first specimen was made from a piece of chamois leather by stitching together the respective edges of the wound with a dnlled end surgical needle (item no 382077A purchased from Sulzle Company) which was swaged with a barbed suture In other words, after insertion of the barbed suture into the needle hole, the needle was cnmped about the hole to secure the barbed suture during stitching After stitching closed the wound, the piece of chamois leather was cut to a rectangular shape of about 3 inches (about 76 mm) in length by about 1 25 inches (about 32 mm) in width, where the stitched wound was in the middle of the length and transverse the width The needle was a taper point, curved surgical needle (3/8 of a circle), with a length of about 22 mm and a relatively thm diameter of about 0 020 inch (about 0 51 mm)
Then, using the same stitching method a second specimen was made from another piece of chamois leather by stitching together the respective edges of the wound, using a dnlled end surgical needle (item no 383271A purchased from Sulzle Company) swaged with the same kind of barbed suture, I e , the surgical needle was cnmped about the needle hole after insertion of the barbed suture into the hole, to secure the barbed suture dunng stitching For the second specimen, the needle was a taper point curved surgical needle (3/8 of a circle) with a length ol about 22 mm and a suitable thin diameter of about 0 032 inch (about 0 81 mm), although not as thin as the diameter of the needle used for first specimen
Each barbed suture for each specimen was a bi-directional, twist cut multiple spiral, polydioxanone barbed suture like suture 70 in Figure 6A, except that each barbed suture had a diameter of about 0 0115 inch (about 0 291 mm, which is slightly larger than the USP requirement for a size 3 0 synthetic absorbable suture), instead of a suture diameter of about 0 018 inch (about 0 457 mm)
Both the first and the second specimens of stitched chamois cloth were tested for closure strength using a Test Resources Universal Tester, Model 200Q Each specimen was gnpped by two respective serrated jaws Then, each specimen was pulled longitudinally at a rate of about 10 inches per minute (about 254 mm per minute) until complete rupture The peak load m pounds reached before complete wound disruption was recorded as the closure strength The results were that the first specimen (which was sutured with the needle that had
a relatively thin diameter of about 0 020 inch about 0 51 mm) took 5 88 pounds until wound disruption occurred and the specimen pulled apart back into 2 pieces, whereas the second specimen (which was stitched with the needle that had a suitably thin diameter of about 0 032 inch, about 0 81 mm, but not as thin as the needle for the first specimen) took only 2 88 pounds until the wound disruption and the specimen pulled apart back into 2 pieces The results are summarized in Table 13A below
Table 13A (Chamois Cloth Closure Strength)
Specimen Needle Diameter Barbed Suture Diameter Ratio* Pounds to Rupture
First 0 020 inch 0 0115 inch 174 5 88
Second 0 032 inch 0 0115 inch 2 78 2 88
*Ratio of surgical needle diameter to barbed suture diameter
Also, various pieces of rat skin were cut and stitched for testing of more surgical needles swaged with barbed sutures as follows
Three freshly killed Sprague-Dawley rats, each about 600 to 700 g, were used Two full-thickness skin incisions were made on the back of each rat to create wounds Each wound was about 4 cm in length and parallel to the spine
For each rat, one of the two wounds was closed with a drilled end, curved surgical needle that was a Sulzle item no 382273A, which was 3/8 circle The needle had a length of 18mm and a diameter of about 0 022 inch (about 0 56 mm) Also, the needle had a taper point needle tip where the needle tip had been ground to a 3-facet cut to approximate a taper cutting needle tip to facilitate penetration of rat tissue The needle was swaged to a barbed suture
The other of the two wounds was closed using the same suturing technique, but with a drilled end, curved surgical needle that was a Sulzle item no 832679A, which was 3/8 circle The needle had a length of about 18 mm and a diameter of about 0 026 inch (about 0 66 mm) Also, the needle had a diamond point needle tip The needle was swaged to a barbed suture
Each baibed suture for each specimen was a b1 directional, twist cut multiple spiral, polydioxanone barbed suture like suture 70 in Figure 6A, except that each barbed suture had a diameter of about 0 015 inch (about 0 381 mm, which is slightly larger than the USP requirement for a size 2 0 synthetic absorbable suture), instead of a suture diameter of about 0 018 inch (about 0 457 mm)
For each stitched wound, a tissue specimen that was approximately a square measuring about 4 cm x about 4 cm, with the stitched wound in the middle paralleling two opposing tissue edges, was retrieved for closure strength testing
The force to open each wound was determined using a Test Resources Universal Tester, Model 200Q For each tissue specimen, the two edges paralleling each stitched wound were mounted m the two respective serrated jaws of the tester
Then, each specimen was pulled longitudinally at a rate of about 2 inches per minute (about 51 mm per minute) until complete rupture occurred The maximum force encountered before complete wound disruption was recorded as the closure strength
The results were averaged from the first set of three wounds closed with a needle having a diameter of about 0 022 inch (about 0 56 mm) and swaged to a barbed suture Also, the results were averaged from the second set of three wounds closed with a needle having a diameter of about 0 026 inch (about 0 66 mm) and swaged to a barbed suture
The results are summarized in Table 13B below
Table 13B (Rat Skin Closure Strength)
Average of 3 Wounds Specimens Needle Diameter Barbed Suture Diameter Ratio* Pounds to Rupture
First set of 3 0 022 inch 0 015 inch 147 119
Second set of 3 0 026 inch 0 015 inch 1 73 8 1
*Ratio of surgical needle diameter to barbed suture diameter
Thus, the lower the ratio of surgical needle diameter to barbed suture diameter, then the better the closure strength when suturing a wound closed with a surgical needle attached to a barbed suture In general, the thinner the surgical needle, the better the closure strength, particularly for delicate tissues, however, for tough tissues, such as muscle and bowel, thicker needles are preferred Thus, what is important, regardless of whether the needle is thick or thin or somewhere in the middle, is that the ratio of surgical needle diameter to barbed suture diameter should be about 3 1 or less, more preferably about 2 1 or less
Although the present invention has been shown and described in detail with regard to only a few exemplary embodiments of the invention, it should be understood by those skilled
in the art that it is not intended to limit the invention to the specific embodiments disclosed Various modifications, omissions, and additions may be made to the disclosed embodiments without materially departing from the novel teachings and advantages of the invention, particularly m light of the foregoing teachings For instance, the barbed suture of the present invention can be used alone or with other closure methods, such as staples and/or skin adhesives, to aid in holding the position of the tissue Accordingly, it is intended to cover all such modifications, omissions, additions, and equivalents as may be included withm the spirit and scope of the invention as defined by the following claims





WE CLAIM:
1. A barbed suture for connecting human or animal tissue, said suture comprising (a) an elongated body having a first end and a second end and (b) a plurality of barbs projecting from the body, each barb facing in a direction and being adapted for resisting movement of the suture, when in tissue, in an opposite direction from the direction in which the barb faces, the barbs having a disposition on the body selected from the group consisting of a staggered disposition, a multiple spiral disposition, an overlapping disposition, a random disposition, and combinations thereof.
2. The barbed suture as claimed in claim 1, wherein the barbs are in a staggered disposition, a multiple spiral disposition, an overlapping disposition, or a combination thereof, and the barbs are all facing in a direction toward only one of the first end and the second end.
3. The barbed suture as claimed in claim 1, wherein the barbs are in a staggered disposition, a multiple spiral disposition, an overlapping disposition, or a combination thereof, and the barbed suture has at least 8L first barbed portion and a second barbed portion, wherein the barbs of the first portion are facing in a direction toward only the first end and the barbs of the second portion are facing in a direction toward only the second end.
4. The barbed suture as claimed in claim 1, wherein the staggered
disposition includes a first set of the barbs being radially spaced
about 180 degrees from a second set of the barbs.
5. The barbed suture as claimed in claim 1, wherein the staggered disposition includes a first set of the barbs being radially spaced about 120 degrees from a second set of the barbs and the second set of the barbs being radially spaced about 120 degrees from a third set of the barbs.
6. The barbed suture as claimed in claim 1, wherein the barbs are in a multiple spiral disposition and the barbed suture is made from a suture filament having a portion that is twisted from about 2 to about 17 times per inch when the barbs are escarped into the suture filament to make the barbed suture.
7. The barbed suture as claimed in claim 1, wherein the barbs are in a multiple spiral disposition and the suture has a spirality angle a ranging from about 5 degrees to about 25 degrees.
8. The barbed suture as claimed in claim 7, wherein the suture has a spirality angle a ranging from about 7 degrees to about 22 degrees.
9. The barbed suture as claimed in claim 8, the suture has a spirality angle a ranging from about 12 degrees to about 18 degrees.
10. The barbed suture as claimed in claim 1, wherein the barbs are in
an overlapping disposition such that for at least two adjacent barbs,
one being an overlapping barb and one being an overlapped barb, the
overlapping barb has an underside and the overlapped barb has a
topside where part of the underside of the overlapping barb is derived from part of the topside of the overlapped barb.
11. The barbed suture as claimed in claim 10, wherein the barbs are in an overlapping disposition such that for at least two adjacent barbs, one being an overlapping barb and one being an overlapped barb, each of the overlapping barb and the overlapped barb having a barb cut length, and the overlapping barb and the overlapped barb having a barb cut distance between them that is less than the barb cut length of the overlapped barb.
12. The barbed suture as claimed in claim 1, wherein the suture is made from a material selected from the group consisting of a bio-absorbable material, a non-absorbable material, and combinations thereof.

13. The barbed suture as claimed in claim 12, wherein the bio-absorbable material is selected from the group consisting of polydioxanone, polylactide, polyglycolide, polycaprolactone, and combinations thereof.
14. The barbed suture as claimed in claim 12, wherein the nonabsorbable material is selected from the group consisting of a polymer, a metal, a metal alloy, a natural fiber, and combinations thereof.
15. The barbed suture as claimed in claim 14, wherein the polymer is selected from the group consisting of polyamide, polyester,
polypropylene, polyurethane, polytetrailuoroethylene, polyether-ester, and combinations thereof.
16. A barbed suture for connecting human or animal tissue, said suture comprising (a) an elongated body having a first end and a second end and a diameter and (b) a plurality of barbs projecting from the body, each barb facing in a direction and being adapted for resisting movement of the suture, when in tissue, in an opposite direction from the direction in which the barb faces, wherein:
(I) the barbs have a disposition on the body selected from the
group consisting of a staggered disposition, a multiple spiral
disposition, an overlapping disposition, a random disposition, and
combinations thereof, and
(II) the barbs have a configuration selected from the group
consisting of a barb cut angle 9 ranging from about 140 degrees to
about 175 degrees, a barb cut depth with a ratio of the barb cut depth
to the suture diameter ranging from about 0.05 to about 0.6, a barb
cut length with a ratio of the barb cut length to the suture diameter
ranging from about 0.2 to about 2, a barb cut distance with a ratio of
the barb cut distance to the suture diameter ranging from about 0.1
to about 6, a corrugated barb underside, an arcuate barb base, at
least two sets of barbs with each set having a barb size different from
the barb size of the other set, and combinations thereof.
17. The barbed suture as claimed in claim 16, wherein the suture is made from a material selected from the group consisting of a bio-
absorbable material, a non-absorbable material, and combinations thereof.
18. The barbed suture as claimed in claim 17, wherein the bio-absorbable material is selected from the group consisting of polydioxanone, polylactide, polyglycolide, polycaprolactone, and combinations thereof.
19. The barbed suture as claimed in claim 17, wherein the nonabsorbable material is selected from the group consisting of a polymer, a metal, a metal alloy, a natural fiber, and combinations thereof.
20. The barbed suture as claimed in claim 19, wherein the polymer is selected from the group consisting of polyamide, polyester, polypropylene, polyurethane, polytetrafluoroethylene, polyether-ester, and combinations thereof.
21. A barbed suture for connecting human or animal tissue, said
suture comprising (a) an elongated body having a first end, a second
end and a diameter and (b) a plurality of barbs projecting from the
body, each barb facing in a direction and being adapted for resisting
movement of the suture, when in tissue, in an opposite direction from
the direction in which the barb faces, wherein:
(I) the barbs have a disposition on the body comprising a staggered disposition, and
(II) the barbs have a configuration comprising (i) a barb cut 0 angle ranging from about 140° to about 175°, (ii) a barb cut depth with a ratio of the barb cut depth to the suture diameter ranging from about 0.05 to about 0.6, (iii) a barb cut length with a ratio of the barb cut length to the suture diameter ranging from about 0.2 to about 2, and (iv) a barb cut distance with a ratio of the barb cut distance to the suture diameter ranges from about 0.1 to about 6.
22. A barbed suture for connecting human or animal tissue, said suture comprising (a) an elongated body having a first end, a second end and a diameter and (b) a plurality of barbs projecting from the body, each barb facing in a direction and being adapted for resisting movement of the suture, when in tissue, in an opposite direction from the direction in which the barb faces, wherein:
1(1) the barbs have a disposition on the body comprising a twist cut multiple spiral disposition with a spirality angle a ranging from about 5° to about 25°, and
(II) the barbs have a configuration comprising (i) a barb cut 0 angle ranging from about 140° to about 175°, (ii) a barb cut depth with a ratio of the barb cut depth to the suture diameter ranging from about 0.05 to about 0.6, (iii) a barb cut length with a ratio of the barb cut length to the suture diameter ranging from about 0.2 to about 2, and (iv) a barb cut distance with a ratio of the barb cut distance to the suture diameter ranges from about 0.1 to about 6.
23. A barbed suture for connecting human or animal tissue, said
suture comprising (a) an elongated body having a first end, a second
end and a diameter and (b) a plurality of barbs projecting from the
body, each barb facing in a direction and being adapted for resisting
movement of the suture, when in tissue, in an opposite direction from
the direction in which the barb faces, wherein:
(I) the barbs have a disposition on the body comprising an overlapping disposition, and
(II) the barbs have a configuration comprising (i) a barb cut 9 angle ranging from about 140° to about 175°, (ii) a barb cut depth with a ratio of the barb cut depth to the suture diameter ranging from about 0.05 to about 0.6, (iii) a barb cut length with a ratio of the barb cut length to the suture diameter ranging from about 0.2 to about 2, and (iv) a barb cut distance with a ratio of the barb cut distance to the suture diameter ranges from about 0.1 to about 6.
24. A barbed suture for connecting human or animal tissue, said
suture comprising (a) an elongated body having a first end, a second
end and a diameter and (b) a plurality of barbs projecting from the
body, each barb facing in a direction and being adapted for resisting
movement of the suture, when in tissue; in an opposite direction from
the direction in which the barb faces, wherein:
(I) the barbs have a disposition on the body comprising a random disposition, and
(II) the barbs have a configuration comprising (i) a barb cut 9 angle ranging from about 140° to about 175°, (ii) a barb cut depth

with a ratio of the barb cut depth to the suture diameter ranging from about 0.05 to about 0.6, (iii) a barb cut length with a ratio of the barb cut length to the suture diameter ranging from about 0.2 to about 2, and (iv) a barb cut distance with a ratio of the barb cut distance to the suture diameter ranges from about 0.1 to about

Documents:

1013-delnp-2005-abstract.pdf

1013-delnp-2005-claims.pdf

1013-delnp-2005-complete specification (as file).pdf

1013-delnp-2005-complete specification (granted).pdf

1013-delnp-2005-correspondence-others.pdf

1013-delnp-2005-correspondence-po.pdf

1013-delnp-2005-description (complete).pdf

1013-delnp-2005-drawings.pdf

1013-delnp-2005-form-1.pdf

1013-delnp-2005-form-18.pdf

1013-delnp-2005-form-2.pdf

1013-delnp-2005-form-3.pdf

1013-delnp-2005-form-5.pdf

1013-delnp-2005-gpa.pdf

1013-delnp-2005-pct-101.pdf

1013-delnp-2005-pct-102.pdf

1013-delnp-2005-pct-105.pdf

1013-delnp-2005-pct-202.pdf

1013-delnp-2005-pct-210.pdf

1013-delnp-2005-pct-220.pdf

1013-delnp-2005-pct-304.pdf

1013-delnp-2005-pct-308.pdf

1013-delnp-2005-pct-901.pdf

1013-delnp-2005-petition-137.pdf

1013-delnp-2005-petition-138.pdf


Patent Number 242071
Indian Patent Application Number 1013/DELNP/2005
PG Journal Number 33/2010
Publication Date 13-Aug-2010
Grant Date 09-Aug-2010
Date of Filing 15-Mar-2005
Name of Patentee QUILL MEDICAL, INC.
Applicant Address 2505 MERIDIAN PARKWAY, SUITE 150, RESEARCH TRIANGEL PARK, NC 27713, USA
Inventors:
# Inventor's Name Inventor's Address
1 JEFFREY C. LEUNG 4413 WHITE CHAPEL WAY, RALEIGH, NC 27615, USA
2 GREGORY L. RUFF 118 CAMPBELL LANE, CHAPEL HILL, NC 27514, USA
3 MATTHEW A. MEGARO 118 STONERIDGE DRIVE, CHAPEL HILL, NC 27514, USA
PCT International Classification Number A61B
PCT International Application Number PCT/US2003/030674
PCT International Filing date 2003-09-29
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10/065,280 2002-09-30 U.S.A.