WO2022031220A1

WO2022031220A1 - Suture and system for cosmetic enhancement

Info

Publication number: WO2022031220A1
Application number: PCT/SG2020/050456
Authority: WO
Inventors: Nir Ellenbogen
Original assignee: I-Support Pte. Ltd.
Priority date: 2020-08-05
Filing date: 2020-08-05
Publication date: 2022-02-10
Also published as: WO2022031220A8

Abstract

There is provided a suture comprising: an anchor portion, a stem, and a plurality of barbs, the plurality of barbs being formed on a portion of the stem, where each of the plurality of barbs may incline towards the anchor portion. The anchor portion may be wider than the stem, and the anchor portion, the stem and the plurality of barbs form a one-piece suture.

Description

SUTURE AND SYSTEM FOR COSMETIC ENHANCEMENT

Field

The present invention relates to a suture and a system for cosmetic enhancement.

Background

Many devices and methods have been developed over the years for face lift procedures, with the aim to minimise wounding, scarring and tissue dissection caused by these procedures. One such device is the barbed suture. Early generations of face lift procedures using barbed sutures typically require at least two entry/exit wounds per suture, or multiple entry and exit points. This may result in significant bleeding, require a significant amount of anaesthetic and/or a significant recovery time for patients. More recent procedures provide a system and method that involves implantation of a suture assembly via one entry site with no exit site, which reduces injury and recovery time for patients of these procedures.

In these methods, the suture assembly typically comprises a suture and an anchor. The prior art suture assembly may comprise a suture and an anchor coupled via a knot formed at one end of the suture. Alternatively, the suture assembly may comprise a suture forming a loop and inserted into an anchor. A portion of the suture may be secured within the anchor by a pin. The latter suture assembly may therefore not require a knotting process as is usually required in a suture assembly.

Nonetheless, an assembly process is still required to assemble the suture and the anchor. The assembly process poses difficulties when done manually, particularly because the diameter of the suture and the anchor are small, which are typically in the range of hundreds of micrometres. While there are specialised processes which allow the assembly of these parts to be performed automatically or semi-automatically, these specialised processes require the use of specialised instruments which may not be readily available, or else require trained personnel to operate them.

It is therefore desirable to provide a suture and system for cosmetic enhancement which address at least some of the aforementioned problems and/or provides a useful alternative.

Summary

In general terms, the present invention proposes a minimally invasive device and technique for cosmetic suturing. According to a first aspect, there is provided a suture. The suture comprises: an anchor portion; a stem; and a plurality of barbs formed on a portion of the stem, each of the plurality of barbs inclining towards the anchor portion, wherein the anchor portion is wider than the stem, and the anchor portion, the stem and the plurality of barbs form a one-piece suture.

The anchor portion, the stem and the plurality of barbs may be made of a same material.

The material may be a bio-degradable or bio-absorbable material.

The anchor portion may comprise resilient portions projecting from the anchor portion towards the plurality of barbs.

The anchor portion may be located at an end of the suture.

The anchor portion may comprise a rounded head at a leading end of the anchor portion.

The suture may comprise a plurality of thorn-shaped lumps formed on the stem.

Each of the plurality of thorn-shaped lumps may be formed at a junction between the stem and each of the plurality of barbs.

The stem may comprise one or more stems.

The anchor portion may comprise one or more anchor portions.

According to a second aspect, there is provided a system for cosmetic enhancement. The system comprises: a suture as described above; a sharpened shaft configured to bore a channel through a facial tissue of a patient; a cannula configured to surround the sharpened shaft during boring; and a pushing rod configured to transport the suture into the cannula after the shaft has been withdrawn.

According to a third aspect, there is provided a method of manufacturing for a suture as described above. The method comprises: providing a suture material into a mould; and forming the suture by heating and pressing the suture material in the mould.

A tensile force and a rotational force may be applied to the suture during formation of the suture at a temperature between a melting point of the suture material and a glass transition temperature of the suture material.

Brief Description of Drawings

Exemplary embodiments of the invention will now be described, with reference to the following figures, in which: Figure 1 is a front view of a patient’s facial tissue implanted with a plurality of sutures in accordance with an embodiment;

Figure 2 is a schematic illustration of a suture of an exemplary embodiment;

Figures 3A, 3B, 3C, 3D, 3E and 3F are schematic illustrations of alternative embodiments of the suture of Figure 2, where Figure 3A is a schematic illustration of a suture having a flat head anchor portion comprising resilient portions projecting from the anchor portion, and alternating barbs on each side of a suture stem, Figure 3B is a schematic illustration of a suture having a rectangular anchor portion, Figure 3C is a schematic illustration of a suture having a different arrangement of resilient portions projecting from an anchor portion of the suture, Figure 3D is a schematic illustration of a suture having two anchor portions where one anchor portion is directly coupled to the other anchor portion, Figure 3E is a schematic illustration of a suture having two anchor portions where one anchor portion is coupled to the other anchor portion via the suture stem, and Figure 3F is a schematic illustration of a suture having two suture stems;

Figure 4 is a schematic illustration of an entry punch in accordance with an embodiment;

Figure 5 is a schematic illustration of an assembly of a trocar and a sharpened shaft for use in a cosmetic procedure with the suture of Figure 2 in accordance with an embodiment; and

Figure 6 is a schematic illustration of an assembly comprising the suture of Figure 2, the trocar of Figure 5 and a pushing rod for use in a cosmetic procedure in accordance with an embodiment.

Detailed Description

Figure 1 shows a front view 100 of a patient’s facial tissue implanted with a plurality of sutures 102 in accordance with an embodiment. The suture 102 is designed to effect a distributed lifting force to desired portions of facial tissue of a patient whose face may be subject to rhytides (wrinkles) or ptosis (sagging). The suture 102 may be used to lift tissue in the cheeks 104, temples 106, neck 108 or forehead 110 zones, but it would be clear to a skilled person that lifting of tissues is not limited to these areas and that the suture may be used for lifting tissue in other parts of the body. In each zone, one or more barbed sutures are upwardly implanted within or under the tissue, so that an entry site 112 is at the bottom, and without an exit site. The entry site 112 is below a final implantation position 114 of an anchor portion 202 of the suture 102 when the patient is in an upright position. Each entry site 112 may include more than one implanted suture 102, for example, three implanted suture assemblies may be implanted at different angles as shown in Figure 1. Existing suture face lifts involve a low risk to the patient. However, the exemplary suture 102 allows an even lower risk for the entirely cosmetic procedure. In particular, the skill involved in the cosmetic procedure is reduced because the use of the exemplary suture 102 does not require knotting or any assembly process before or during the procedure. The reduced skill required in conducting the procedure also enables a less experienced practitioner to perform the procedure compared to prior art methods and allows a learning process for performing the procedure to be shortened significantly. Depending on the regulations of the country concerned, it may be possible for non-doctor clinicians, cosmetic technicians or practitioners, nurses or other medical staff to significantly assist, or actually carry out major parts of the non-therapeutic entirely cosmetic procedure. Further, the suture 102 may reduce the number of wounds significantly compared to known methods, and the practitioner is able to provide lift in any location, as there is no need to provide an exit site at an unobtrusive location.

Compared to the prior art suture assemblies as described in the background section, embodiments of the suture of the present disclosure comprises an anchor portion, a stem and a plurality of barbs all formed from a singular piece of material to form a one-piece suture. More specifically, the anchor portion, the stem and the plurality of barbs are all formed from a single piece of material during the manufacture of the suture. This eliminates an assembly process of joining separate components such as the anchor portion and the stem to form the suture since in the suture of the present invention, the anchor portion, the stem, and the plurality of barbs are already intrinsically integrated to form a monolithic piece of the suture as manufactured. Accordingly, sutures of the present disclosure eliminate the need to manually assemble a suture and an anchor, or the need to use expensive specialised equipment to assemble a suture and an anchor semi-automatically or automatically. Further, with minimised handling of the suture prior to the cosmetic procedure, it advantageously ensures sterility and hygiene of the suture. In addition, eliminating the assembly process reduces the manufacturing time, and the required manufacturing manpower, thereby reducing manufacturing cost. Still further, the sutures of the present disclosure may be manufactured in uniform and precise dimensions, and without the assembly process, there is no risk in deforming or damaging the anchor portion and/or the barbs through mishandling during the assembly process.

Suture

Embodiments of a suture 102 will be described with reference to Figures 2, 3A, 3B and 3C, wherein the same reference numerals have been used to indicate the same or similar parts.

As shown in Figure 2, an exemplary embodiment of the one-piece suture 102 comprises an anchor portion 202, a stem 204 and a plurality of barbs 206. The anchor portion 202, the stem 204 and the plurality of barbs 206 are integrated to form the one-piece suture 102. In other words, the anchor portion 202, the stem 204 and the plurality of barbs 206 fused to form a single piece of suture 102. The one-piece suture 102 is therefore a monolithic piece, and no assembly process is required to form the one-piece suture 102. In an embodiment, the anchor portion 202, the stem 204, and the plurality of barbs 206 are made of a same material. The material may comprise a bio-degradable and/or a bio-absorbable material, so that the one-piece suture 102 is bio-degradable and/or bio-absorbable. In some embodiments, particularly when the one-piece suture 102 is manufactured by additive manufacturing, the anchor portion 202, the stem 204, and the plurality of barbs 206 may be made of different materials, and yet formed from a single piece during the manufacturing process to achieve at least the aforementioned advantages.

The anchor portion 202 is located at one end of the one-piece suture 102. It is formed by a rigid portion having a fully closed leading end 208 and a trailing end 210. The leading end 208 comprises a rounded head portion 212, and the trailing end 210 comprises a flat end portion 214. The anchor portion 202 as shown in Figure 2 comprises a generally trapezoidal shape but any other suitable shapes such as a cuboid, sphere, cylinder, or cone may also be used. In the present embodiment, the anchor portion 202 is a solid block. It should be appreciated that in other embodiments, the anchor portion 202 may be partially hollow as long as the anchor portion 202, the stem 204 and the plurality of barbs 206 are integrated to form the one-piece suture 102. The partially hollow anchor portion 202 advantageously reduces the amount of material required to form the one-piece suture 102.

The plurality of barbs 206 are formed on a portion of the stem 204, and are inclined towards the anchor portion 202. As shown in Figure 2, this means that the angle 0 formed between each of the plurality of barbs 206 and a longitudinal axis L of the stem 204 is an acute angle (i.e. less than 90°). Although the plurality of barbs 206 are provided on both sides of the stem 204 as shown in Figure 2, the plurality of barbs 206 may be provided on one side of the stem 204, or may be arranged in a staggered configuration as shown in Figure 3A. As shown in Figure 2, a diameter of each of the plurality of barbs is smaller than that of the stem 204 of the one-piece suture 102 for ease of manufacturing the suture 102, for example by a moulding process. This may however be an unnecessary limitation if the one-piece suture 102 is manufactured by an additive manufacturing process.

The stem 204 connects the anchor portion 202 and the plurality of barbs 206. The stem 204 may comprise a plurality of thorn-shaped lumps 216. The plurality of thorn-shaped lumps 216 formed on the stem 204 may be formed at a junction between the stem 204 and each of the plurality of barbs 206 as shown in Figure 2. The plurality of thorn-shaped lumps 216 may increase a traction between the suture 102 and the surrounding tissues once the suture 102 is implanted, thereby improving the efficacy of the cosmetic procedure. Although the one-piece suture 102 comprises one stem 204, other embodiments of the one-piece suture 102 may include multiple stems 204 connected to one anchor portion 202.

The anchor portion 202 is configured to anchor the one-piece suture 102 in place to provide a necessary reaction force to lifting forces provided by the barbs 206 to the facial tissue. To do so, the anchor portion 202 is at least wider than the stem 204. The anchor portion 202 is also configured to allow the one-piece suture 102 to be pushed into a cannula used for implantation of the one-piece suture 102 in the patient. The method of implanting the one-piece suture 102 into the facial tissue of a patient is described below in relation to Figures 4, 5 and 6.

The one-piece suture 102 of the present embodiment may be of a suitable length. For example, the one-piece suture 102 may be of about 100-400 nm. In particular, the one-piece suture 102 may be 150-350 nm, 200-300 nm, 225-250 nm. The length of the one-piece suture 102 may be selected depending on the part of the body of the user, the size of the user’s body part such as, but not limited to face, where the suture may be used. The stem 204 of the one-piece suture 102 may be approximately 0.4 mm thick. However, different thicknesses of the stem 204 may be provided for supporting different tensile strengths. The anchor portion 202 is wider than the stem 204 and may be 0.5 mm - 2.0 mm wide.

The one-piece suture 102 may be moulded from polymers such as polypropylene, polycaprolactone, polylactic acid, poly(glycolide-co-L-lactide) or polydioxanone. Some of these polymers, such as polydioxanone and polylactic acid, are biocompatible and biodegradable. As such, the one-piece suture 102 does not stay implanted permanently as it will biodegrade over time. This also reduces risk of complications. Exemplary methods for manufacturing the one- piece suture 102 are discussed below. The anchor portion 202 may be made up of a different material from the barbs 206 and the stem 204. The anchor portion 202 may stay inside the tissue and dissolve equally or slower than the barbs 206 and the stem 204, ensuring the reliability of the lift over the lifetime of the one-piece suture 102. As is understood by a skilled person in the art, the one-piece suture 102 is flexible so that it can be handled by the practitioner during implantation of the suture. At the same time, the one-piece suture 102 includes some degree of stiffness so that it can be comfortably inserted into the cannula during the implantation process.

In the present embodiment, no part of the one-piece suture 102 projects beyond the closed leading end 208 of the anchor portion 202. This advantageously enables the practitioner to achieve better precision during implantation of all embodiments of the one-piece suture 102 of the present invention in a patient since no spatial allowance needs to be estimated by the practitioner to accommodate extraneous suture that, in other systems, project beyond the leading end 208 of the anchor portion 202. Such extraneous suture in other systems may comprise one or more knots, or may comprise a knot with free ends of the suture extending further beyond the knot. In the present one-piece suture 102, certainty of the location of the extreme top end of the one-piece suture 102 can be determined by feeling for the anchor portion 202 under the skin since no part of the one-piece suture 102 extends beyond the anchor portion 202 at the implantation site 114.

Further, the present one-piece suture 102 does not require any knot which comprises a significantly larger mass of material than the rest of the one-piece suture 102. Thus, more uniform biodegradation of the one-piece suture 102 can be expected when compared to other systems that use one or more knots in their sutures. Still further, no assembly process is required since the anchor portion 202, the stem 204 and the plurality of barbs 206 are integrated to form the one-piece suture 102. In other words, the one-piece suture 102 as presented to the practitioner is of a single piece and does not comprise separate parts assembled together. This decreases time required for manufacturing a suture and a stopper for anchoring the suture.

Further, since the assembly process of different parts of the suture has been eliminated, there is minimal handling of the one-piece suture 102 during the manufacturing process and by the practitioner. This is advantageous in avoiding damage to the barbs 206 of the one-piece suture 102 which are used for engaging the facial tissue of the patient to effect lift when the one-piece suture 102 is implanted in the patient.

Embodiments of the suture

Various embodiments of the suture are shown in Figures 3A, 3B, 3C, 3D and 3E. As is appreciated by a skilled person, other variations are possible and the examples shown are not exhaustive. Different features as shown in Figures 3A, 3B, 3C, 3D and 3E may also be combined in a mix and match manner to form other embodiments of the one-piece suture 102.

A one-piece suture 300 in accordance with a second embodiment is shown in Figure 3A. The one-piece suture 300 is similar to the one-piece suture 102 as described in relation to Figure 2, except for the configurations of the anchor portion 302 and the plurality of barbs 304. As shown in Figure 3A, the anchor portion 302 is of a truncated generally trapezoidal shape with a flat head 306. The anchor portion 302 comprises at least two resilient portions 308 projecting from the anchor portion 302, in a direction away from the leading end 208 towards the plurality of barbs 304, at an angle y from the longitudinal axis L. The angle y is an acute angle. This constitutes the free state of the at least two resilient portions 308, as shown in Figure 3A. The at least two resilient portions 308 may be configured to be displaceable towards the central longitudinal axis L of the anchor portion 302 to result in the anchor portion 302 being in a compressed state. In the compressed state, the greatest lateral diameter or width of the anchor portion 302 is within the diameter of the entry site. This allows passage of the anchor portion 302 through a cannula to the entry site during implantation in the patient. During implantation, upon the anchor portion 302 of the one-piece suture 300 exiting the cannula, the at least two resilient portions 308 spring back to their undisplaced positions so that the anchor portion 302 is again in the free state. In the free state, the at least two resilient portions 308 are configured to engage facial tissue of a patient to enhance inhibition of downward movement of the anchor portion 302 when the anchor portion 302 is implanted in the final implantation position 114 in the patient. This results in a better grip of the facial tissue by the one-piece suture 300 when compared to sutures with anchors/anchor portions without the resilient portions 308. As shown in Figure 3A, the at least two resilient portions 308 are symmetrically provided about the central longitudinal axis L of the one-piece suture 300, at the trailing end 210 of the anchor portion 302. In other embodiments, the at least two resilient portions 308 are provided at the leading end 208 of the anchor portion 302. This is for example shown in Figure 3C. The barbs 304 are provided on both sides of the stem 204 in a staggered configuration. In other words, each of the plurality of barbs 304 is provided in an alternate manner on each side of the stem 204, where only one barb is provided on one side of the stem at any one junction 310, as depicted in Figure 3A.

Figure 3B shows a third embodiment of a one-piece suture 312. The one-piece suture 312 is similar to the one-piece suture 102 as described in relation to Figure 2, except for the configuration of the anchor portion 314. As shown in Figure 3B, the anchor portion 314 is of a generally cuboidal shape with a flat head 316. The anchor portion 314 of the third embodiment comprises at least two resilient portions 318 projecting from the anchor portion 314, in a direction laterally away from the leading end 208 of the anchor portion 314 towards the plurality of barbs 206. In this embodiment, the at least two resilient portions 318 are projected substantially parallel to the longitudinal axis L. In another words, the angle y is zero or close to zero for this embodiment.

Figure 3C shows a fourth embodiment of a one-piece suture 320. The one-piece suture 320 is similar to the one-piece suture 102 as described in relation to Figure 2, except for the configuration of the anchor portion 322. Similar to the anchor portion 202 of the one-piece suture 102, the anchor portion 322 is of a generally trapezoidal shape with a rounded head portion 212. However, in contrast to the anchor portion 202 of the one-piece suture 102, the anchor portion 322 comprises a plurality of resilient portions 324 at the trailing end 210 and at least two resilient portions 326 at the leading end 208 of the anchor portion 322. The plurality of resilient portion 324 at the trailing end 210 are projecting from the anchor portion 322, in a direction away from the leading end 208 towards the plurality of barbs 304, at an angle a from the longitudinal axis L, where the angle a is an acute angle. The at least two resilient portions 326 at the leading end 208 of the anchor portion 322 are projecting in a direction away from the leading end 208 towards the plurality of barbs 304, at an angle p from the longitudinal axis L. As shown in Figure 3C, the angle is more than the angle a in this embodiment. In other embodiments, the angle p is less than or equal to the angle a.

Figure 3D shows a fifth embodiment of a one-piece suture 330 in which the anchor portion 202 comprises more than one anchor portion 331, 332. The one-piece suture 330 is similar to the one-piece suture 102 as described in relation to Figure 2, except that the anchor portion 202 of the one-piece suture 102 now comprises two anchor portions 331, 332 as shown in this embodiment. As shown in Figure 3D, the anchor portions 331, 332 are similar in size and shape, with the anchor portion 332 coupling directly to a leading end 334 of the anchor portion 331. The anchor portion 332 comprises a rounded head 336 which forms the leading end 338 of the one-piece suture 330 in the present embodiment. In some embodiments, the anchor portions 332 and 331 may be of different size and/or shape to each other. The size and shape of the anchor portions 332, 331 may be modified to suit the needs of the cosmetic procedure involved.

Figure 3E shows a sixth embodiment of a one-piece suture 338. The one-piece suture 338 is similar to the one-piece suture 330 as shown in Figure 3D except that the anchor portion 332 is coupled to the anchor portion 331 via the stem 204. The distance between the anchor portion 332 and the anchor portion 331 may be modified and adjusted depending on the needs of the cosmetic procedure concerned. Similarly, although the anchor portion 332 is similar/identical to the anchor portion 331 as shown in Figure 3E, in another embodiment, the anchor portion 332 may have a different size and/or shape to the anchor portion 331.

Figure 3F shows a seventh embodiment of a one-piece suture 340 in which the stem 204 comprises more than one stem, such as stems 341 , 342. The one-piece suture 340 is similar to the one-piece suture 102 as described in relation to Figure 2, except that the stem 204 of the one-piece suture 102 now comprises two stems 341, 342 in this embodiment, where a plurality of barbs 344, 346 are formed on a respective portion of each of the stems 341, 342. The stems 341 , 342 and the plurality of barbs 344, 346 are connected to the anchor portion 202 at the trailing end 210 of the anchor portion 202. The stems 341, 342 may be connected to the anchor portion 202 at two different points of the anchor 202 as shown in Figure 3F. Each of the stems 341 , 342 may comprise a respective plurality of thorn-shaped lumps 348, 350. Similar to the plurality of thorn-shaped lumps formed on the stem 204 for the one-piece suture 102, the pluralities of thorn-shaped lumps 348, 350 formed on the respective stems 341 , 342 may be formed at junctions between the stems 341 , 342 and each pair of the pluralities of barbs 344, 346 as shown in Figure 3F. Although only two stems 341 , 342 are shown in Figure 3F, it should be appreciated that additional stems may be connected to the anchor portion 202. The stems 341 , 342 are parallel to each other as shown in Figure 3F. However, it should be appreciated that the stems 341 , 342 may also be connected to the anchor portion 202 at an angle <|) to each other, which may be 0-45°. The stems 341, 342 are flexible and may be compressed in the compressed state to allow passage of the suture 340 through a cannula to the entry site during implantation of the one-piece suture 340 in the patient.

Further, it should be appreciated that in an embodiment, a one-piece suture may comprise more than one anchor portion connected to more than one stem and more than one pluralities of barbs, where the more than one anchor portion, the more than one stem and the more than one pluralities of barbs are formed from a single piece of material to form the one-piece suture.

Lifetime

In embodiments where the one-piece suture 102, 300, 312, 320, 330, 338, 340 is made of a biodegradable material, the one-piece suture 102, 300, 312, 320, 330, 338, 340 may degrade by hydrolysis in approximately 6 to 24 months after implantation, depending on the type of biodegradable material used. After this point the procedure will need to be redone.

Manufacturing of the suture

The one-piece sutures 102, 300, 312, 320, 330, 338, 340 of the exemplary embodiments may be moulded, or manufactured by additive manufacturing methods using a suitable suture material, such as a biodegradable polymer. Each of these are discussed below.

Forming the one-piece sutures 102, 300, 312, 320, 330, 338, 340 of the exemplary embodiments by moulding may generally involve two steps. In a first step, a preformed suture, comprising an anchor portion, a stem and a plurality of barbs, is formed by heating and pressing a suitable suture material (e.g. a biodegradable polymer) in a mould using a solid-phase forming method. In a second step, a tensile force and a rotational force are applied to the preformed suture at a temperature T, preferably between a melting point (T_m) of the suture material and a temperature of about 30°C less than the melting point (i.e. T_m > T > T_m - 30° C), in a vacuum state.

In the first step, the suture material is heated to a temperature between a melting point (T_m) of the suture material and a glass transition temperature (T_g) of the suture material. By performing the heating and pressing step in this temperature range, a desired shape of the suture may be maintained even when the compression force of the pressing step is removed. This is because if the temperature is below this range, for example at room temperature, the preformed suture may fill the formation space only temporarily, and may retract and shrink from the desired shape once the compression force applied is removed due to elasticity of the suture material. Further, the heating and pressing of the suture material may be performed when the suture material (for example a polymer suture with appropriate dimensions) is fastened at two ends so that shrinking deformation of the suture material may be suppressed. By applying a tensile force during the heating and pressing step, the ductility of the suture may increase. The pressure used for pressing the suture material in the mould may range from 10 kgf/cm² to 200 kgf/cm², and more preferably, may range from 80 kgf/cm² to 160 kgf/cm².

The mould used for manufacturing the suture preform may be configured to include a formation space and an overflow space. The overflow space may be formed along a boundary of the formation space. The formation space and the overflow space may be partitioned by a separation wall. The formation space should have appropriate dimensions for forming a suture with the desired width, length and thickness as described above. The overflow space allows for excess suture material to flow in from the formation space via an introduction portion during the solid phase pressing formation process. The depth of the overflow space may be controlled so that the depth of the overflow space is less than the depth of the formation space. Preferably, the overflow space may be a depth of 50 pm to 100 pm, and a width of 250 pm to 500 pm.

In the second step, a tensile force and a rotational force are applied to the preformed suture which may be anchored at two ends. The magnitude of the tensile force ranges from 10% to 30% of the maximum tensile strength of the preformed suture. When the tensile force is applied, the rotational force is simultaneously applied, so that a twist occurs in the preformed suture. The magnitude of the rotational force is proportional to the length of the preformed suture, and the rotation angle of the two ends ranges from 727cm (minimum) to 3607cm (maximum). Heating may be applied in this second step so that the temperature for performing this step is between the glass transition temperature (T_g) and the melting point (T_m) of the suture material used for producing the preformed suture. Preferably, the temperature T is between the melting point to about 30 °C less than the melting point (i.e. T_m > T > T_m - 30° C). The heating time for this step may be about 24 to 48 hours.

Additive Manufacturing

The one-piece sutures 102, 300, 312, 320, 330, 338, 340 of the various embodiments as discussed above may also be formed using an additive manufacturing process. An example of additive manufacturing is 3D printing. However, other methods of additive manufacturing may also be used. Rapid prototyping or rapid manufacturing are also terms which may be used to describe additive manufacturing processes.

As used herein, “additive manufacturing” refers generally to manufacturing processes wherein successive layers of material(s) are provided on each other to “build-up” layer-by-layer or “additively fabricate”, a three-dimensional component. This contrasts with subtractive manufacturing methods (such as milling or drilling), where a material is successively removed to fabricate the part. In additive manufacturing, successive layers generally fuse together to form a monolithic component which may have a variety of integral sub-components. In the present case, an additive manufacturing process, such as 3D printing, may allow the exemplary sutures to be integrally formed. In other words, the entire suture including the anchor portion, the plurality of barbs and the stem forms a one-piece suture and is produced as a singular piece of product.

Additive manufacturing methods described herein enable manufacture of the exemplary sutures to any suitable size and shape with various features which may not have been possible using prior manufacturing methods. Additive manufacturing can create complex geometries without the use of any sort of tools, molds, or fixtures, and with little or no waste material. Instead of machining components from solid billets of plastic or metal, much of which is cut away and discarded, the only material used in additive manufacturing is what is required to form the part.

Suitable additive manufacturing techniques in accordance with the present disclosure include, for example, Fused Deposition Modeling (FDM), Selective Laser Sintering (SLS), 3D printing such as by inkjets and laserjets, Sterol ithography (SLA), Direct Selective Laser Sintering (DSLS), Electron Beam Sintering (EBS), Electron Beam Melting (EBM), Laser Engineered Net Shaping (LENS), Electron Beam Additive Manufacturing (EBAM), Laser Net Shape Manufacturing (LNSM), Direct Metal Deposition (DMD), Digital Light Processing (DLP), Continuous Digital Light Processing (CDLP), Direct Selective Laser Melting (DSLM), Selective Laser Melting (SLM), Direct Metal Laser Melting (DMLM), Direct Metal Laser Sintering (DMLS), Material Jetting (MJ), NanoParticle Jetting (NPJ), Drop On Demand (DOD), Binder Jetting (BJ), Multi Jet Fusion (MJF), Laminated Object Manufacturing (LOM) and other known processes.

The additive manufacturing processes described herein may be used for forming the one-piece sutures as described by using any suitable material. Suitable materials include polymers such as polypropylene, polycaprolactone, polylactic acid, polydioxanone or poly(glycolide-co-L- lactide). Some of these polymers, such as polydioxanone, poly(glycolide-co-L-lactide), and polylactic acid, are biocompatible and biodegradable. In addition, if necessary, the sutures may be formed from a combination of different materials/components by additive manufacturing. For example, the additively manufactured sutures described herein may be formed in part, in whole, or in some combination of materials including but not limited to pure metals or alloys. These materials are examples of materials suitable for use in additive manufacturing processes which may be suitable for the fabrication of the one-piece sutures as described herein.

Cosmetic procedure and procedure kit

An example of a cosmetic procedure involving the one-piece suture 102 of Figure 2 is described alongside Figure 1. A procedure kit, comprising an entry punch, a trocar, an insertion hub, and a pushing rod, for use with the one-piece suture 102 in the cosmetic procedure is described in relation to Figures 4, 5 and 6. It should be appreciated that although the cosmetic procedure is described in relation to the one-piece suture 102, it is also applicable to other embodiments of the one-piece suture 300, 312, 320, 330, 338, 340 as shown in Figures 3A, 3B, 3C, 3D, 3E and 3F.

To perform the implantation, anaesthetic may first be applied to an area around the entry site 112. In the present embodiment as shown in Figure 1 , the entry site 112 is formed just above the jawbone, near the middle of the cheek. A trocar, comprising a plastic cannula and a sharpened shaft, is inserted through the entry site 112 towards the anchor site 114. The sharpened shaft is configured to bore a channel through the facial tissue of the patient, while the cannula is configured to surround the sharpened shaft during boring. Once the channel is bored, the sharpened shaft is withdrawn, and an insertion hub is engaged with the cannula. A pushing rod configured to transport the one-piece suture 102 into the cannula, seats the anchor portion 202 of the one-piece suture 102 and transports the anchor portion 202 up to the anchor site 114. The cannula is withdrawn while keeping pressure on the anchor portion 202 of the one-piece suture 102. The pushing rod is then withdrawn. The facial tissue is reconfigured according to the desired outcome. The one-piece suture 102 is tensioned and any excess suture is trimmed. The entry site is formed using an entry punch 400 as shown in Figure 4. The entry punch 400 may be shipped in a sterile state, with a sealed cover in a sterile inert gas. The entry punch 400 has a hollow metal shaft with a bevelled sharpened tip for puncturing the skin to make the initial opening for the entry site.

The trocar 500 is shown in Figure 5. The trocar 500 is integrally moulded from plastic with the cannula 502. A metal shaft 504 inserted in the cannula 502. The shaft 504 may have a sharpened tip 506 which extends from the cannula 502. The trocar 500 and the shaft 504 may be shipped together in a sterile state, with a sealed cover in a sterile inert gas. Alternatively, they may be supplied separately. The cannula 502 and the shaft 504, may be 45mm or 100mm long. The cannula 502 has a slightly tapered tip, to assist entry into the tissue. The sharpened tip 506 is at an angle of 30° - 40° from the longitudinal axis of the shaft 504 to assist entry into the tissue. The cannula 502 may alternatively be extruded from metal, and/or may have the same or higher stiffness as the metal shaft 504.

As shown in Figure 6, an insertion hub 602 is provided to assist with implantation. Prior to implantation of the one-piece suture 102, the one-piece suture 102 is threaded through the insertion hub 602. The insertion hub connects the anchor portion 202 of the one-piece suture 102 with the procedure equipment in a stable way such that the one-piece suture 102 can be inserted easily into and through the cannula 502. The insertion hub 602 is moulded from polycarbonate or polypropylene. It is frustoconical in shape with an angle of 24°, a length of 19.75mm and an outer diameter of 5.9mm. Its internal cavity is shaped as a circle with an inner diameter of 1.44mm. The outer surface includes a mating ledge for the procedure equipment and four spaced ribs for rigidity.

During the procedure, the insertion hub 602 engages the trocar 500, as shown in Figure 6. A pushing rod 604 forces the anchor portion 202 into the cannula 502, but no further than the end of the cannula. The pushing rod 604 may include a seat designed to engage with the anchor portion 202 to reliably push it into the cannula 502. The seat should distribute the force around the anchor portion 202, to avoid twisting or jamming, and to easily disengage from the anchor portion 202 when retracted.

Alternatively, the insertion hub 602 may be dispensed with, in which case the trocar 500 includes a guided entrance so that pushing rod 604 can insert the seated anchor portion 202 directly into the cannula 502.

Whilst there have been described in the foregoing description preferred embodiments of the present invention, it will be understood by those skilled in the technology concerned that many variations or modifications in details of design or construction may be made without departing from the present invention.

Claims

1. A suture comprising: an anchor portion; a stem; and a plurality of barbs formed on a portion of the stem, each of the plurality of barbs inclining towards the anchor portion, wherein the anchor portion is wider than the stem, and the anchor portion, the stem and the plurality of barbs form a one-piece suture.

2. The suture of claim 1, wherein the anchor portion, the stem and the plurality of barbs are made of a same material.

3. The suture of claim 2, wherein the material is a bio-degradable or bio-absorbable material.

4. The suture of any preceding claim, wherein the anchor portion comprises resilient portions projecting from the anchor portion towards the plurality of barbs.

5. The suture of any preceding claim, wherein the anchor portion is located at an end of the suture.

6. The suture of any preceding claim, wherein the anchor portion further comprises a rounded head at a leading end of the anchor portion.

7. The suture of any preceding claim, further comprising a plurality of thorn-shaped lumps formed on the stem.

8. The suture of claim 7, wherein each of the plurality of thorn-shaped lumps is formed at a junction between the stem and each of the plurality of barbs.

9. The suture of any preceding claim, wherein the stem comprises one or more stems.

10. The suture of any preceding claim, wherein the anchor portion comprises one or more anchor portions.

11. A system for cosmetic enhancement comprising: a suture according to any one of claims 1 to 10; a sharpened shaft configured to bore a channel through a facial tissue of a patient; a cannula configured to surround the sharpened shaft during boring; and a pushing rod configured to transport the suture into the cannula after the shaft has been withdrawn.

12. A method of manufacturing the suture according to any one of claims 1 to 10, the method comprising: providing a suture material into a mould; and forming the suture by heating and pressing the suture material in the mould.

13. The method of claim 12, wherein a tensile force and a rotational force is applied to the suture during formation of the suture at a temperature between a melting point of the suture material and a glass transition temperature of the suture material.