阅读说明：本技术 伤口闭合装置 (Wound closure device ) 是由 E·迪亚兹 V·弗里德里希 L·放克 M·格拉西亚 Y·马尔克斯 P·土龙多尔斯 于 2020-03-26 设计创作，主要内容包括：一种伤口闭合装置(1),特别地,外科缝合线(1),包括：-伸长主体(2),其具有带有直径D的横截面区域；以及-凸出部,其从所述伸长主体(2)突出,其中,-所述凸出部中的每个呈具有带有底座长度L的下底座部分(4、4')、上顶部部分(5、5')、以及高度H的鳍状角形锚固元件(3、3')的形状,-所述锚固元件(3、3')沿着伸长主体(2)的长度沿纵向方向一个接一个地布置于至少两个排(6、7)中,其中,在任何排(6、7)中的任何两个锚固元件(3、3')之间有距离G,-排(6)中的所述锚固元件(3)中的每个关于任何另一排(7)的每个对应的锚固元件(3')对准,并且,-位于排(6)中的两个连续锚固元件(3)之间的伸长主体(2)的每个区段(8)具有相同的沿纵向方向渐缩的形状,其具有在伸长主体(2)的横截面面积方面平稳的改变或基本上平稳的改变。(Wound closure device (1), in particular a surgical suture (1), comprising: -an elongated body (2) having a cross-sectional area with a diameter D; and-projections protruding from the elongated body (2), wherein-each of the projections is in the shape of a fin-shaped angular anchoring element (3, 3') having a lower base portion (4, 4') with a base length L, an upper top portion (5, 5'), and a height H, -the anchoring elements (3, 3') are arranged one after the other in at least two rows (6, 7) in a longitudinal direction along the length of the elongated body (2), wherein there is a distance G between any two anchoring elements (3, 3') in any row (6, 7), -each of the anchoring elements (3) in a row (6) is aligned in relation to each corresponding anchoring element (3') of any other row (7), and-each section (8) of the elongated body (2) located between two consecutive anchoring elements (3) in a row (6) has the same tapering in the longitudinal direction Has a smooth change or a substantially smooth change in the cross-sectional area of the elongated body (2).)

1. Wound closure device (1), in particular a surgical suture (1), comprising:

-an elongated body (2) having a cross-sectional area with a diameter D; and

-a protrusion protruding from the elongated body (2),

wherein the content of the first and second substances,

-each of said projections has the shape of a flipper angular anchoring element (3, 3') having a lower base portion (4, 4') with a base length L, an upper top portion (5, 5'), and a height H,

-the anchoring elements (3, 3') are arranged one after the other in at least two rows (6, 7) in a longitudinal direction along the length of the elongated body (2), wherein there is a distance G between any two anchoring elements (3, 3') in any row (6, 7),

-each of the anchoring elements (3) in a row (6) is aligned with respect to each corresponding anchoring element (3') of any other row (7), and,

-each segment (8) of the elongated body (2) between two consecutive anchoring elements (3) in a row (6) has the same shape tapering in the longitudinal direction with a smooth or substantially smooth change in the cross-sectional area of the elongated body (2).

2. Wound closure device according to claim 1, characterized in that there are two rows (6, 7) of anchoring elements (3, 3'), wherein preferably said rows (6, 7) have a rotational offset of 180 ° from each other with respect to the longitudinal axis of the elongated body (2).

3. Wound closure device according to any of the preceding claims, characterized in that the anchoring element (3, 3') has an arched shape, wherein preferably the anchoring element (3, 3') has an arched upper top portion (5, 5 ').

4. Wound closure device according to any one of the preceding claims, characterized in that the anchoring element (3, 3') has at least one sharp edge (9) at its upper top portion (5, 5'), preferably at its arched upper top portion (5, 5 ').

5. Wound closure device according to claim 4, characterized in that the sharp edge (9) is defined by an apex angle α ≦ 70 ° in a side view, in particular by an apex angle α between 15 ° and 60 °, preferably by an apex angle α between 20 ° and 55 °.

6. Wound closure device according to any one of the preceding claims, characterized in that there is an inclination angle β ≦ 85 ° between the anchoring element (3, 3') and the elongated body (2), in particular an inclination angle β between 20 ° and 80 °, preferably between 20 ° and 75 ° and further preferably between 35 ° and 65 °.

7. Wound closure device according to any one of the preceding claims, characterized in that all anchor elements (3) in a row (6) have the same height H, wherein preferably all anchor elements (3, 3') in all rows (6, 7) have the same height H.

8. Wound closure device according to any one of the preceding claims, characterized in that the distance G between any two anchoring elements (3) in a row (6) is constant, wherein preferably the distance G between any two anchoring elements (3, 3') in any row (6, 7) is constant.

9. Wound closure device according to any one of the preceding claims, characterized in that the ratio between the diameter D and the height H is from 1:0.3 to 1:5, in particular from 1:0.8 to 1:3, preferably from 1:1 to 1:2, and/or the ratio between the diameter D and the distance G is from 1:0.8 to 1:15, in particular from 1:1 to 1:10, preferably from 1:1.5 to 1:6, and/or the ratio between the base length L and the distance G is from 1:0.8 to 1:6, in particular from 1:1 to 1: 3.

10. Wound closure device according to any one of the preceding claims, characterized in that most, and preferably all, of the anchoring elements (3) in a row (6) have the same orientation, and in particular that most of the sharp edges (9) of the anchoring elements (3) are also directed along the length of the elongated body (2) in the same longitudinal direction.

11. Wound closure device according to claim 10, wherein said majority or all of the anchoring elements (3, 3') or sharp edges (9) in all rows (6, 7) are directed in the same longitudinal direction along the length of the elongated body (2).

12. Wound closure device according to any one of the preceding claims, in particular claim 10 or claim 11, characterized in that the wound closure device comprises at least two parts of an elongated body (2) with anchoring elements (3, 3'), wherein the anchoring elements (3, 3') of the two parts and in particular also the sharp edges (9) of the anchoring elements (3, 3') are directed in opposite longitudinal directions along the length of the elongated body (2).

13. The wound closure device according to any one of the preceding claims, in particular according to any one of claims 10 to 12, characterized in that there is at least one portion of the elongated body (2) having no projection, wherein preferably said portion having no projection is provided at an end of the elongated body (2) having a projection, in particular at an end of the surgical suture.

14. Wound closure device according to any one of the preceding claims, characterized in that the wound closure device, in particular the surgical suture, comprises at least one sharp end, preferably a surgical needle, at least one end of the elongated body (2).

15. The wound closure device according to any one of the preceding claims, wherein the wound closure device, in particular the surgical suture, comprises at least one stop element.

16. Wound closure device according to claim 15, in the form of a surgical suture (21), wherein all anchoring elements (23, 23') in all rows have the same unidirectional orientation, comprising a surgical needle (24) at one end of the elongated body (22) and a stop element (25) at the other end of the elongated body (22).

17. Method for producing a wound closure device, in particular a surgical suture, according to one of the preceding claims, wherein,

an unstretched elongated body, in particular an unstretched monofilament, is pre-stretched in its longitudinal direction,

-creating a cut in the elongated body after pre-stretching, and,

-the elongated body with the cutting portion is stretched along its longitudinal direction.

Technical Field

The present invention relates to a wound closure device, in particular to a surgical suture. The wound closure device generally includes an elongated body having a cross-sectional area with a diameter D and a projection projecting from the elongated body. As a result, the wound closure device according to the invention may also be named as a wound closure device with so-called barbs, in particular barbed sutures.

Background

Wound closure devices with barbs (barbs), in particular barbed sutures (sutures), have been developed for many years in order to improve e.g. the holding strength of the sutures and/or to obviate the need for knotting. Corresponding devices have been used for wound closure, for tissue support and for repair of internal tissues such as tendons and ligaments.

Examples for barbed sutures were disclosed earlier, for example in US-A-3123077 and GB-A-1091282. The first publication shows a surgical suture having sharp-edged resilient barbs projecting from an elongated body of the suture in various arrangements. The second publication also shows a suture having a plurality of barbs.

EP-A2-1656890 describes a machine and a method for producing barbed sutures. Corresponding machines and methods may be used to produce barbed sutures in a regular or staggered arrangement.

Furthermore, barbed sutures are disclosed in EP-A1-1075843, wherein protrusions having pointed ends are arranged one after the other along a length of surgical thread. Preferably, the projections alternate in sections from one to four positions.

In WO-a2-2004/030704, a barbed suture for connecting tissue is disclosed, the barbed suture having an elongated body and a plurality of barbs projecting from the body. The disposition of the barbs on the body may be staggered, twisted cut multiple spiral (twist), overlapping, or random.

The barbed suture disclosed in WO-a1-2009/020795 includes a shaft/body extending longitudinally along a length of the suture and a plurality of barbs extending outwardly from the shaft. The barbs are asymmetric, wherein the shape and diameter of the shaft between the barbs is constant.

EP-a1-2449981 describes a barbed medical device wherein each barb extending from the elongated body has two different cut angles, and wherein the diameter of the elongated body is constant.

Finally, in WO-a1-2013/048947, a wound closure device with a stop element coupled to the distal end of a filamentary element is disclosed. In a preferred embodiment, the wound closure device may have a plurality of projections extending outwardly from the filamentary element. The filamentary element has a constant diameter throughout its length.

In view of the above-mentioned prior art disclosures, it is also desirable to provide a wound closure device with self-anchoring capability, i.e. a wound closure device with barb elements/projections, such that the device (in particular a suture) can be pulled through tissue in one direction, but resists movement in the opposite direction. However, in this context, the present invention has the objective of providing an improved knotless wound closure capability aimed at securing tissue securely without the use of knots. This improvement in the anchoring strength of the suture/device should be provided while maintaining the suture/device passing through the biological tissue in one direction before the suture/device is anchored in the opposite direction.

This and further objects are solved by a wound closure device having the features of claim 1 and a method for producing the wound closure device according to claim 17. Preferred embodiments of the inventive wound closure device are defined in the claims depending on claim 1. All claim terms are herein incorporated by express reference into the description of the invention.

Disclosure of Invention

With reference to what is mentioned hereinbefore, the present invention discloses a wound closure device comprising an elongated body having a cross-sectional area with a diameter D and a projection protruding from the elongated body, i.e. over an (outer) surface of the elongated body. Furthermore, in accordance with the present invention,

each of said projections is in the shape of a fin-like angular anchoring element having a lower base portion with a base length L, an upper top portion, and a height H,

the anchoring elements are arranged one after the other in at least two rows in the longitudinal direction along the length of the elongated body, wherein there is a distance G between any two anchoring elements in any row,

-each of the anchoring elements in one row is aligned with respect to each corresponding anchoring element of any other row, and,

each section of the elongated body between two consecutive anchoring elements in a row has the same shape tapering in the longitudinal direction with a smooth or substantially smooth change in the cross-sectional area of the elongated body and, as a result, a corresponding change in the diameter D.

The following explanation of the terms used to define the subject matter of claim 1 (i.e. the inventive wound closure device) may be further understood by reference to fig. 1 and 2. As a result, the disclosures of these two figures 1 and 2 can be used to further clarify these explanations.

The term "fin-shaped angle-shaped anchoring element" is to be understood as meaning an anchoring element which substantially takes the shape of a vertical fin or vertical stabilizer of the tail unit or tail wing of an aircraft. In this context, according to the invention, the opposite sides of the shape do not necessarily have to be parallel.

These fin-shaped angular anchoring elements, which are protrusions or barbs projecting beyond the surface of the elongated body, have a lower base portion with a base length L, wherein, according to fig. 2, this base length L is defined on the elongated body via a virtual plane on the elongated body and two parallel planes defined by the limits of the anchoring element. Furthermore, the fin-shaped anchoring element has an upper top portion (see fig. 1) and a height H. According to fig. 2, this height H is defined via an imaginary plane on the elongated body and the upper limit of the anchoring element.

The diameter D according to the invention is defined as the distance, in particular the minimum distance, between two opposite points located on a virtual plane perpendicular to the longitudinal direction of the elongated body between successive anchoring elements, over the cross-sectional area of the elongated body. According to fig. 2, the diameter D is marked with respect to a wound closure device having two rows of anchoring elements with a rotational offset of 180 °. In this diagrammatic representation, D is chosen as the tapered section of the elongated body between two successive anchoring elementsMinimum sizeOver the cross-sectional areaMinimum sizeDistance.

In this context, it has to be mentioned that the diameter D may also be defined as the "inner diameter" of the inventive device, since this diameter D characterizes the inventive device without taking the anchoring element into account. As will be discussed later, one may also define an "outer diameter D0" that takes into account the anchoring elements that protrude from the elongated body. As can be seen from fig. 2, the (outer) diameter D0 may be defined as the (inner) diameter D +2 · height H. Obviously, this definition may vary, since, for example, according to the invention, not all anchoring elements necessarily have to have the same height H.

Furthermore, as shown in fig. 1, the distance G between two adjacent anchoring elements in a row will be understood as the distance between the outer limits of the two anchoring elements facing in the same direction along the length of the elongated body.

As stated above, each of the anchoring elements in one row must be aligned with respect to each corresponding (opposite) anchoring element of any other row. The term "aligned" will be understood as that there is no significant deviation in the position of the corresponding anchoring element with respect to an imaginary plane perpendicular to the longitudinal direction along the length of the elongated body and parallel to the cross-sectional area of the elongated body. In particular, it is preferred that, in the diagrammatic representation according to fig. 2, the base length L plotted for the anchoring elements in one row must have an overlap at least with the base length L plotted for each corresponding (opposite) anchoring element in any other row (which must be "aligned" with respect to the anchoring elements mentioned initially).

Finally, according to the invention, each section of the elongated body between two consecutive anchoring elements in a row has a tapered shape, i.e. it has substantially the geometry of a truncated cone. Moreover, this truncated cone having its shape tapering in the longitudinal direction has a smooth change or substantially smooth change in the cross-sectional area of the elongated body. Preferably, the smaller (top) region of said truncated cone is oriented in the longitudinal direction of the elongated body, which body is to be inserted into the tissue in the longitudinal direction of the elongated body before anchoring (see e.g. fig. 2).

According to the invention, each section of the elongated body between two consecutive anchoring elements in a row has substantially the same shape tapering in the longitudinal direction (with the corresponding anchoring element in the middle). One can thus also define the inventive wound closure device in such a way that it is put together by the above-mentioned segments having the same shape tapering in the longitudinal direction or in such a way that those segments are repeated to form the inventive wound closure device (with the corresponding anchoring elements in between).

Although the inventive wound closure device, in particular a surgical suture, may consist of several filaments (filaments) braided or twisted together or may be a pseudo-monofilament (braided or twisted core with sleeve), it is preferably a monofilament, i.e. it consists of only one thread-like structure.

As disclosed hereinabove, according to the invention there must be at least two rows of anchoring elements along the length of the elongated body in the longitudinal direction, wherein said anchoring elements in one row are aligned with respect to each corresponding anchoring element of any other row. As a result, it is possible to provide, for example, three or four rows of anchoring elements on the elongated body.

Nevertheless, in a preferred embodiment of the invention, two rows of anchoring elements projecting from the elongated body are preferably provided. While it is possible to have those two rows rotationally offset (spaced from each other) by any reasonable angle (e.g., at 90 ° or 120 °), it is preferred that the two rows have a rotational offset of 180 ° from each other about the longitudinal axis of the elongate body. With this arrangement of the anchoring elements in the two rows, the anchoring strength of the device (in particular, the suture) is improved.

As defined above, and with further reference to fig. 2, the finned angle anchoring element in the inventive device may be described as having the shape of a vertical fin of an aircraft tail. In this context, it can also be said that in a preferred embodiment of the inventive device, the anchoring element has a trapezoidal shape. This trapezoidal shape will be considered to be directed towards the anchoring element in side view.

According to the invention it is further preferred that the anchoring element has an arched shape, wherein preferably the anchoring element has an arched upper top portion. Preferred features of these anchoring elements will be explained in more detail in the context of the figures. The arched contact area of the anchoring element (in particular, the upper top portion thereof) allows an improved anchoring of the anchoring element in the tissue.

Furthermore, according to the invention, it is preferred that the anchoring element has at least one sharp edge at its upper top portion (preferably at its arched upper top portion). In the latter case, preferably, a crowned sharp edge is provided on each anchoring element, which sharp edge extends along the upper top portion of each anchoring element. As will be explained later in the context of the figures, the sharp edge significantly improves the anchoring strength of the device in biological tissue.

The excellent anchoring effect of the inventive suture is related to the characterized open geometry of the inventive surgical suture with an anchor element having a flipper-like angular shape, resulting in a primary suture-tissue intermediate contact occurring primarily preferably in the arched upper top portion of the anchor element.

The sharp edge as mentioned above may preferably be defined by a top angle α in a cross-sectional view, for example as explained in fig. 2 for example. Preferably, the apex angle α may be ≦ 70 °, wherein preferably the apex angle α is between 15 ° and 60 °. Within this latter range, an apex angle between 20 ° and 55 ° is further preferred.

Referring now to the inclination of the anchoring element in relation to the surface of the elongated body, the inclination angle β may be defined (see fig. 2), i.e. between an imaginary plane on the elongated body and a corresponding plane defined by the (inner) limits of the anchoring element. In this context, it is possible to provide the anchoring element with a tilt angle β of 90 ° between the anchoring element and the surface. In these embodiments, the anchoring element will protrude vertically from the longitudinal body. However, since this is beneficial for (smooth) passage of the inventive device through biological tissue (in one direction), the tilt angle β ≦ 85 ° is preferred. With regard to these embodiments, the anchoring element is yieldable (give way) or even (slightly) bendable in a direction towards the surface of the elongated body, where appropriate. In this context, an inclination angle β of between 20 ° and 80 ° is preferred, wherein, within this range, an inclination angle β of between 20 ° and 75 ° is further preferred. Also preferred is an inclination angle β between 35 ° and 65 °.

According to the invention, not all anchoring elements in a row have to have the same height H. In principle, it is possible to choose the height H of the anchoring elements in a row randomly or in a specific (e.g. alternating) order. Nevertheless, it is preferred that all the anchoring elements in a row have the same height H. This choice of the same height H also has advantages in terms of production of the inventive device as will be explained later.

In view of the above discussion of the height H in relation to the anchoring elements in one row, it is also preferred that the anchoring elements in all rows on the elongate body have the same height H.

Furthermore, it is possible to choose different distances G between two anchoring elements in a row, with respect to the distance G between any two anchoring elements in any row. In this context, it is also possible to choose the distance G randomly or in a specific order (e.g. in an alternating order). Nevertheless, it is preferred, in particular for reasons of easier manufacturability, that the distance G between any two anchoring elements in a row is constant.

In order to optimize the inventive device by maintaining easy passage of the device through biological tissue in one direction while significantly improving the anchoring strength of the device in the opposite direction, it is preferred to choose a specific ratio between the diameter D related to the cross-sectional area of the elongated body and the parameters mentioned above (i.e. height H and distance G). Also, a specific ratio between the base length L and the distance G may have advantages. To determine these ratios, in the context of fig. 1 and 2, the diameter D, height H, distance G, and base length L are determined as explained above.

As a result, a preferred embodiment of the invention is defined by a ratio between the diameter D and the height H of from 1:0.3 to 1:5, in particular from 1:0.8 to 1: 3. Within the latter range, a ratio D: H from 1:1 to 1:2 is further preferred.

Moreover, a ratio between the diameter D and the distance G of from 1:0.8 to 1:15, in particular from 1:1 to 1:10, is preferred. Within the latter range, a ratio D: G from 1:1.5 to 1:6 is further preferred.

As regards the ratio between the length L of the base and the distance G, values for these ratios from 1:0.8 to 1:6, in particular from 1:1 to 1:3, are preferred.

As already mentioned, it is preferred according to the present invention that the new wound closure device is a surgical suture or a surgical thread. Such a surgical suture is a classic example of an inventive device having an elongated body and a projection protruding across a surface of the elongated body according to a feature of the present invention.

Furthermore, it is preferred that in the following examples, inventive devices (in particular, inventive surgical sutures) are provided: wherein a majority of the anchoring elements in a row are directed along the length of the elongate body in the same longitudinal direction, i.e. they have the same orientation along the length of the elongate body. In this context, if sharp edges are provided at the anchoring elements, it is further preferred that a majority of the sharp edges are also directed along the length of the elongated body in the same longitudinal direction.

With reference to the preferred embodiments mentioned hereinbefore, it is further preferred that all of the anchoring elements in a row (in particular, also all of the sharp edges of the anchoring elements) are directed along the length of the elongated body in the same longitudinal direction.

If most of the anchoring elements, and possibly their sharp edges, are directed in the same longitudinal direction, it will be appreciated that it is possible to pass the device through tissue in one direction, while the device resists movement in the opposite direction. This effect is even higher in the following cases: not only a majority of the anchoring elements/sharp edges, but also all anchoring elements/sharp edges are directed along the length of the elongated body in the same longitudinal direction.

In this context, it is also understandable that this effect is even much higher in the following cases: most of all rows of anchoring elements or sharp edges or even all rows of anchoring elements or sharp edges are directed in the same longitudinal direction, which relates to a further preferred embodiment of the inventive device.

A wound closure device (in particular a surgical suture) may be designated as a "unidirectional" or "unidirectional" barbed device or suture if most or all of the anchor elements/sharp edges of one or preferably all of the rows have the same orientation, i.e. are directed in the same longitudinal direction.

With regard to other embodiments of the inventive device, there are at least two portions of the elongated body having an anchoring element, wherein preferably the anchoring elements of the two portions and in particular also the sharp edges of the anchoring elements are directed in opposite longitudinal directions along the length of the elongated body. The inventive devices according to these embodiments resist movement of the device in opposite directions in tissue, so that there is a flexible application for those inventive devices. If there are two portions of the elongate body with anchor elements directed in opposite longitudinal directions, the corresponding device or suture may be designated as a "bi-directional" barbed device or suture.

According to the invention, it is also possible to provide the inventive device or suture with at least one portion of the elongated body having no projection. As a result, there are portions of the device that have the inventive function of barbed devices or sutures and portions of the device that do not have that function. Thus, the anchoring elements are provided only along the length of the elongate body in those parts where the function of the anchoring elements/barbs is desired. For example, those portions without projections may be provided between portions with projections directed in opposite longitudinal directions.

With regard to the last-mentioned embodiment, it is further preferred that said portion of the elongated body without the projection is provided at least one (same) end of said elongated body, in particular at an end of said surgical suture. Typically, at the (same) end, at least one sharp end or needle is provided to enable the device or suture to enter into and/or pass through the biological tissue.

Preferably, in the embodiments of the inventive device mentioned above in relation to the parts of the elongated body without protrusions, those parts without protrusions have a diameter D1 representing the cross-sectional area of said parts, the diameter D1 being different from (in particular, larger than) the (inner) diameter D representing the cross-sectional area of the elongated body with the anchoring element.

According to the invention, in a preferred embodiment, the wound closure device (in particular, a surgical suture) comprises at least one sharp end, in particular a surgical needle, at least one end of the elongated body. This end of the elongated body having the sharp end or the surgical needle is oriented opposite to the corresponding anchoring element, i.e. opposite to the longitudinal direction in which the corresponding anchoring element (and possibly also the sharp edge of the anchoring element) is directed. Preferably, the sharp tip or surgical needle is provided at a portion of the elongated body without the projection, wherein said portion without the projection preferably has a diameter D1 which is larger than the diameter D of the elongated body with the projection/anchoring element.

With reference to the embodiments mentioned above, a unidirectional or unidirectional barbed device or suture may be provided with a sharp end or a surgical needle at one (proximal) end of the elongated body and with an anchoring element directed in a longitudinal direction opposite to the direction with the sharp end or the needle end. The following possibilities also exist: the bi-directional barbed device or suture is provided with a sharp end or a surgical needle at both ends of the elongated body, wherein the two parts of the elongated body having the anchoring element are each directed in a direction opposite to the longitudinal direction of its sharp end or needle.

The diameter of the sharp tip, in particular the diameter of the surgical needle (which is designated as DN hereinafter), is chosen to support the function of the inventive device, in particular the inventive suture. In this context, on the one hand, the diameter DN must be large enough so that the inventive device can be inserted into tissue and guided through tissue in one direction. On the other hand, with respect to the present invention, in contrast to the surgical sutures known from the prior art, the anchoring capacity is not so related or limited to the incision channels and guide channels caused by the sharp ends (in particular, the surgical needles) in the tissue. Due to the advantageous design of the inventive wound closure device, in particular the inventive surgical suture, wherein its anchoring elements have a flipper-horn shape, strong contact between the walls of the incision channel and the guide channel and the anchoring elements of the inventive device is possible. This is especially true in the case of realizing the preferred features and ratios mentioned in the dependent claims of the invention. In these cases, the anchoring element of the inventive device is particularly protruding and stable, resulting in a very strong interaction between the inventive device with its anchoring element and the tissue in which the device is used.

As a result, it is not only possible to use a surgical needle in the case of the present invention having a diameter DN which is greater than or equal to the (outer) diameter D0 of the inventive surgical suture (since this is also true with respect to barbed sutures known from the prior art). According to the invention, it is also possible and even preferred to choose a smaller diameter DN of the surgical needle than the (outer) diameter D0 of the inventive surgical suture (D0 ≧ DN). Due to the specific design of the inventive surgical suture, in these cases sufficient anchoring capability in the tissue may also be provided.

Further preferred is a specific ratio between the diameter DN and the diameter D0 of from 1:0.70 to 1:1.70, preferably from 1:0.75 to 1:1.60, in particular from 1:0.80 to 1: 1.40.

According to the invention, preferably, the elongated body and the projection (i.e. the anchoring element) are made of the same material. According to these embodiments, the entire wound closure device, in particular the entire surgical suture, preferably in the form of a monofilament, consists essentially of the corresponding material (possibly except for any sharp end (e.g. surgical needle) and/or any stop element and/or any additive or active agent).

The materials for the inventive device can in principle be selected from all materials already used in the art, in particular from polymers, in particular for surgical sutures. The polymer may be a resorbable polymer or a non-resorbable polymer or a partially resorbable polymer. Examples of polymers that can be used are homopolymers, copolymers, terpolymers or tetramers, etc. Suitable polymers are, for example, block polymers, in particular block copolymers or block terpolymers or graft polymers. It is also possible to use any or random or alternative copolymers or terpolymers according to the invention.

In the preferred embodiment, the use ofThe material is prepared from materials including polylactide, polyglycolide and polyCaprolactone, polydioxanone, polytrimethylcarbonate, polyhydroxybutyric acid, mixtures thereof, copolymers thereof and terpolymers thereof. The materials used are also preferably selected from the group consisting of lactide, glycolide, trimethylene carbonate, p-dioxanone, andresorbable copolymers or terpolymers of at least one monomer of the group of caprolactone. For example, materials useful in the present invention may be prepared from materials including glycolide, trimethylene carbonate, anda trimer of caprolactone, preferably a triblock trimer.

The non-resorbable material may be a polymer, a metal alloy or natural fibers, such as silk or cotton. However, in this embodiment, the non-resorbable polymer is particularly preferably from the group comprising polyolefins, polyesters, polyamides, polyurethanes, mixtures thereof, copolymers thereof and terpolymers thereof. For example, the material according to the invention may be formed from polypropylene, polyethylene terephthalate, linear and preferably aliphatic polyurethane, polytetrafluoroethylene and/or nylon.

In a further preferred embodiment, the material used comprises at least one additive as active agent. The additive may be part of the corresponding material, for example, the additive may be blended or mixed with the material. However, it is also possible that these additives are provided in the form of a coating or layer on the material (e.g. on the surface of the elongate body and/or projections). Preferably, the material used comprises additives selected from the group consisting of biological agents, medical agents, pharmaceutical agents, cells and/or combinations thereof.

The bioactive agent is preferably a differentiation factor, a growth factor, a restoration factor and/or an adhesion factor. Suitable growth factors may be selected from the group consisting of Fibroblast Growth Factor (FGF), Transforming Growth Factor (TGF), Platelet Derived Growth Factor (PDGF), Epidermal Growth Factor (EGF), granulocyte-macrophage colony stimulating factor (GMCSF), Vascular Endothelial Growth Factor (VEGF), insulin-like growth factor (IGF), Hepatocyte Growth Factor (HGF), interleukin-1B (IL-1B), interleukin-8 (IL-8), Nerve Growth Factor (NGF), and combinations thereof.

The medical and/or pharmaceutical preparation may be an antibacterial agent, in particular an antibiotic agent, a disinfectant, a tumor preparation, a wound healing agent, an anti-scarring agent, an analgesic, a growth promoter, an anti-inflammatory agent, an analgesic and/or an odor control agent.

Suitable antimicrobial agents may be selected from the group consisting of biguanides, chlorhexidine diacetate (CHD), polyhexamethylene biguanide (PHMB), triclosan, gentamicin, copper, zinc, silver, gold, Salts thereof (Salts), stereoisomers thereof, and combinations thereof.

A preferred anti-scarring agent may be an angiotensin I enzyme inhibitor, such as captopril.

For example, a preferred cell additive may be somatic cells, in particular autologous cells such as fibroblasts, chondrocytes and or precursor cells, in particular stem cells. Cellular additives to the material are advantageous because, for example, substances produced and secreted by the cells can help accelerate wound healing.

Furthermore, substances like e.g. collagen and/or hyaluronic acid may be particularly beneficial in orthopedics to achieve cosmetically satisfactory results like e.g. wrinkle smoothing.

The inventive wound closure devices, in particular the inventive surgical sutures, may be produced according to different methods, for example by cutting methods or by molding methods (from melting or dissolving, injection molding, compression molding, and others). Blanking, drilling, laser action and over-moulding are also possible methods.

Preferably, however, the inventive devices (in particular, the inventive sutures) are produced according to an inventive method in which,

1. the unstretched elongated body (preferably, a monofilament) is pre-stretched along its longitudinal direction (along its length),

2. the cut portion is made into a pre-stretched elongated body, and then,

3. this pre-stretched elongated body with the cut-out is stretched or stretched (split) in its longitudinal direction in order to form the inventive surgical suture with the anchor element according to the invention. After this stretching step, the elongated body has a diameter D1 in any part where no cut has been provided according to step 2 and a diameter D in all parts where a cut has been provided according to step 2.

The unstretched elongated suture, preferably provided in the form of a monofilament, preferably has a circular or elliptical cross-sectional area. However, it is also possible to provide other cross-sectional shapes to the suture. For example, the suture thread may have a triangular, square, trapezoidal, rhomboidal, pentagonal, hexagonal, star-shaped or cross-shaped region as a cross section. Such a shape can for example easily be formed with the aid of an extrusion die which can be provided with any desired cross-sectional shape for the extruded body.

In one aspect, the pre-stretching step serves to straighten the fibers and remove the wire memory caused by the rounded shape of the spindle onto which the fibers are wound after extrusion. On the other hand, it is advantageous to prepare the fibers for the following cutting process, since during pre-stretching the fibers and their surfaces become stiffer. It is assumed that this change in the stiffness of the fiber results from alignment/crystallization of the polymer chains during pre-stretching.

During the cutting step, exactly one cut must be provided for each anchoring element that is later present in the inventive device (i.e. on the corresponding elongated body). As a result, in order to provide the tabs for the inventive device arranged one after the other in at least two rows, it is necessary, in the cutting step, to provide a cut for each tab in at least two rows. According to the invention, if a preferred arrangement of the projections in two rows with a rotational offset of 180 ° is to be provided, in a second production step, the cutting portions have to be provided in two rows with a rotational offset of 180 °. All of these cuts may be provided individually or in groups simultaneously or all of the cuts may be provided together simultaneously. For example, all cuts in a row may be made simultaneously.

In this context it has to be mentioned that, with the inventive method, in a normal scenario, there will be no bulge protruding above the surface of the material during the cutting process. The cutting process will result only in a cut and not a bulge.

In order to produce the inventive device, in particular the inventive suture, it is preferred that in the second step the cut is placed at an angle ≦ 70 °, preferably between 15 ° and 60 °, in particular between 20 ° and 55 °, with respect to the longitudinal axis of the monofilament.

As regards the diameter of the unstretched elongated body (raw material of step 1), it is preferred that the cut is provided at a depth of between 5% and 50%, in particular between 25% and 45%, of this diameter.

The cutting portion may preferably be provided mechanically by using at least one cutting blade. In this context, it is possible, for example, to provide all the cuts in one row using only one blade and then provide the corresponding cuts in (at least) the other row. Nevertheless, it is also possible to use two or more blades, so as to provide (aligned) cuts in at least two rows simultaneously. In all of these cutting processes, the suture or blade(s) may be moved to bring the blade(s) to the location of the next cut(s).

The bulge protruding from the material is provided by the third step mentioned above, i.e. the stretching/stretching step, wherein the suture material, preferably a pre-stretched monofilament (with cut), is pulled (split). In this step, for example, the pre-stretched monofilament material is further stretched/elongated, whereby the flipper angle element according to the invention protrudes. Simultaneously, a section according to the invention is formed having a shape tapering in the longitudinal direction. After the second (cutting) step, the suture thread, in particular the monofilament material (with cut), is brought into its stretched state. This is done by pulling the material apart over at least part of its length. In this third step, the material is elongated and, simultaneously, the fin-shaped angular anchoring element rises over the surface of the elongated body. Moreover, a corresponding section between two consecutive anchoring elements is formed having a tapered shape.

The drawing step may preferably be carried out with heating, depending on the material (in particular, polymeric material) from which the monofilament is made. A typical temperature range for the stretching step is between 20 ℃ and 150 ℃.

Furthermore, the inventive wound closure device, in particular the inventive (unidirectional) surgical suture, may preferably comprise at least one stop element at the end of the elongated body, which is directed in a longitudinal direction along which the anchor element is directed, and possibly also along which the sharp edge of the anchor element is directed. The stop element has the following functions: after the device has been anchored in the tissue via the anchoring elements provided on the elongated body of the device, the position of the device is further fixed in or with respect to the tissue. As a result, the stop element may also be named a fixation element or a locking element or a fixation actuator or an end effector or the like. Various stop elements known from the prior art are disclosed, for example, in WO-A2-2005/112787.

The stop elements used according to the invention may be in the form of (small) bars, (small) tabs, (small) plates or (small) strips, among others. With all of these embodiments, the corresponding stop element extends (or is capable of extending during use) radially outwardly of the elongate body in a plane substantially perpendicular to the longitudinal axis of the elongate body. To enhance its function, the stop element may include additional features such as additional self-gripping elements (e.g., rake stop elements).

Further embodiments of stop elements that can be used according to the invention include rings, double rings, slip rings or slip knots. Other embodiments include a (short) bi-directional barbed segment as a retaining element or a ball as a retaining element.

Other stop elements that may also be used in accordance with the present invention include structures that can be converted from a unzipped configuration to a zipped configuration during use. These are configurations with a zig-zag locking design or with a spring locking design.

Moreover, the tubular build may act as a stop element, wherein, for example, during use of the surgical suture, the initially tubular element locks to the planar element, thereby blocking further movement of the suture.

According to the invention, it is preferred to use stop elements in the form of flat tabs. Such tabs, together with the elongated body of the surgical suture, impart a so-called "T-shape" to the suture with the stop element. Surgical sutures with these stop elements in the form of tabs can also be converted into this "T-shaped" design when the surgical suture is anchored in tissue. This will be explained later in connection with the figures.

The stop element in the form of a tab may have a circular shape, an oval shape or an angular shape. In the case of angular tabs, it is preferred that the edges of these angular tabs (triangular, rectangular, square, etc.) are rounded in order to avoid any unnecessary tissue damage.

Depending on the actual design of the tab-shaped stop elements, the maximum dimension (length, width, diameter) of these stop elements preferably does not exceed 4.5 mm, and preferably ≦ 3.5 mm. For example, in the case of a rectangular tab-shaped stop element, the greater dimension in the plane of the tab is preferably ≦ 4 mm, in particular between 3.5 mm and 2.5 mm, and the smaller dimension ≦ 3.5 mm, in particular between 2 mm and 1 mm.

The thickness of the tab serving as a stop element preferably does not exceed 0.4 mm. Preferably, the thickness is ≦ 0.3 mm, preferably between 0.2 mm and 0.1 mm.

The stop elements that can be used according to the present invention can be made of any suitable material that has been used in the art as a material for surgical sutures. Thus, any of the suture materials and structures discussed above may be used to construct the stop elements discussed in this description.

It is further preferred that the stop element used with the surgical suture is made of the same material as the material used for the surgical suture.

Methods for producing a retaining element according to the present disclosure are within the purview of one skilled in the art and include, but are not limited to, blanking, die cutting, drilling, laser action, molding (melting, dissolving, injecting, compressing, etc.) and overmolding. Also, the stop elements may be constructed by glue, adhesive, ultrasonic or thermal welding or other methods as selected by one of ordinary skill in the art.

Further advantages and features of the invention will become clear from the following description of examples and drawings in conjunction with the dependent claims. The individual features can be realized individually or in combination in the corresponding embodiments of the invention. The drawings are only for purposes of illustrating and better understanding the invention and are not to be construed as limiting the invention in any way.

Example 1

Production of inventive surgical sutures

Step 1: extrusion

Prior to extrusion, the polygluconate particles are< 10^-1The drying was carried out under vacuum at 70 ℃ for 18h under a pressure of mbar. The extrusion was performed on a Berstorff twin screw extruder (temperature profile 205 ℃, 215 ℃) connected to a melt pump (215 ℃, 0.25 ccm/rev, 17.7 rpm (nominal value), die pressure 130 ± 30 bar) to ensure a uniform flow of the polymer melt through the filament die and thus a uniform diameter of the resulting filaments. After passing through the die, the resulting fibers were quenched in a water bath (44 ℃ ± 2 ℃) and passed through motorized godet/rolls (speed of 10 rpm) to be finally wound into a layer on a cylindrical rotating shaft made of metal. The monofilaments obtained had an average diameter of 0.645. + -. 0.010 mm. The monofilament fibres were held on a metal rotating shaft at 18 ℃ for 5h in order to crystallize and then subjected to post-treatment at 40 ℃ for 3h, applied<Vacuum of 10 mbar.

Step 2: pre-stretching

The unstretched (unstretched) polygluconate monofilament as provided in step 1 was cut into parts having a length of about 60 cm and then fixed to the jaws of an automatic stretching oven at a distance of 460 mm. Then, in a stretching oven, pre-stretching of the monofilaments with a ratio of 1:1.84 was performed at a temperature of 120 ± 2 ℃ and at a stretching speed of 5 mm/s.

And step 3: cutting of pre-stretched monofilaments

The pre-stretched polygluconate monofilament component as provided in step 2 is fixed at its ends to the clamps of the cutting machine and held there under a certain tension. The cutting machine is equipped with different cutting modules that cut successively through the surface of the monofilament, the wire parts being rotated 180 ° by means of the clamp and again cut at the same cutting depth as compared to the first one. In this way, identical cuts are in aligned arrangement in two rows along the monofilament component. Depending on the configuration of the final product, there are two different operational settings: unidirectional and bidirectional.

To obtain a unidirectional configuration, only one cutting module provided with blades is used. As an example, the cutting angle is 40 °, and the spacing between the cuts is selected to be 0.20 mm. A total of 736 cuts were made into the undrawn monofilament fibers.

For the bidirectional configuration, two symmetrical cutting modules provided with two blades are used. Each cutting unit performs one of two sets of cuts provided in the final product in a bidirectional configuration. The cutting angle was 40 ° and the spacing between the cuts was selected to be 0.20 mm. The two cutting units each perform 736 cuts. In this way, the cuts are arranged in two groups facing each other in opposite directions from the central transition zone of the device where no cuts are present.

During step 3, only cuts into the monofilament material are provided. These cuts do not cause the anchoring elements to project beyond the surface of the monofilament. In step 4, these anchoring elements are formed.

And 4, step 4: stretching/drawing

In order to convert the obtained pre-spread and cut the polygluconate monofilament parts as provided in step 3 into self-anchoring devices, these parts were fixed to the jaws of a stretching oven and stretched at a temperature of 120 ℃ ± 2 ℃ and a stretching speed of 5 mm/s, a stretching ratio of 2:1 was applied.

During said stretching step, an anchoring element is formed according to the invention, having its flipper angular shape and its characteristic tapered section between two consecutive anchoring elements in a row.

The resulting wound closure device had an average length of the bulged section of 14.7 cm and the average diameter of the device in the non-bulged section was about 0.370 mm. The final stretched product produced by the mentioned procedure is characterized by an inner (inner) diameter (D) of 155 ± 17 μm, a base length (L) of 141 ± 6 μm, a height (H) of 182 ± 13 μm, a distance between two anchoring elements (G) of 455 ± 26 μm and angles defined as (α) and (β) having an approximation of 45 ° and 57 ° respectively.

Example 2

Production of a stop element and a surgical suture with a stop element

Step 1: extrusion

The polygluconate particles were dried at 70 ℃ for 18h (overnight). The extrusion was performed on a screw extruder (temperature profile 206 ℃, 205 ℃, 204 ℃) connected to a melt pump (12.5 rpm) equipped to a flat die (210 ℃). After passing through the die, the resulting tape was quenched in a water bath (40 ℃) and passed over a first set of motorized godet/rolls (speed of 4.8 m/min). The resulting tape was then passed through a water bath (30 ℃) and immediately passed to a second set of motorized godet rolls/rolls (26 m/min). The relationship between the speed of the first set of godet rolls/rolls and the speed of the second set of godet rolls/rolls allows a draw ratio of 6.5 to be applied to the resulting belt. The stretching step imparts directional crystallization to the resulting tape, resulting in appropriate resistance. After the stretching step, the strip was air cooled at two ovens and passed over a final set of godets/rolls (31 m/min) to be finally wound into a layer on a cylindrical rotating shaft made of metal. The tape was held at 18 ℃ for 24h on a metal spindle to complete the crystallization process. The resulting tapes had average values for thickness and width of 0.17 mm and 3.794 mm, respectively. Moreover, the tape was characterized by mean values for resistance and elongation of 190N ± 14N and 39% ± 5%, respectively.

Step 2: welding and die cutting

A surgical suture according to the present invention (e.g. manufactured according to example 1), in particular a surgical suture having a unidirectional configuration of its anchoring elements, is provided. The band and the suture produced in step 1 are fixed by flanges on the guide lines of the platform, so as to couple the suture and the band by means of an ultrasonic welding technique. The technique was performed on Sonotronic ultrasound technology equipment (titanium ultrasound generator, 35 kHz). The distance between the ultrasonic generator and the stage was adjusted to 0.29 mm, and the welding time applied was 0.13 s. As a result, the ribbon is welded at the distal end of the barbed wire.

The die cutting process is performed on a punch, wherein its die set is specifically designed to obtain stop elements of the required size and shape (here: 3.0 mm length and 1.5 mm width, rounded edges). The suture with the tape is carefully inserted through the die until the tape is properly placed on the guide. Once the weld is centered at the die, manual pressure is applied, pushing the punch through the material into the die. Finally, a (unidirectional configuration) suture with stop elements is obtained.

Example 3

Determination of anchoring force in inventive surgical sutures and anchoring force in barbed sutures that have been commercially available

In the following, the specific anchoring forces of the inventive surgical suture are shown in comparison with barbed sutures that are already commercially available.

In this context, a unidirectional surgical suture according to the present invention was manufactured according to example 1. The suture is provided for measuring the anchoring force (together with the needle, but without any stop element).

Hereinafter, the parameters of the inventive surgical suture are summarized in table 1.

TABLE 1

It is noted that the size in the inventive surgical suture is not directly related to the diameter of the device, but the size is based on its linear pull tensile strength, which is equivalent to the pull knot tensile strength of a synthetic absorbable suture having the same USP size.

All data included in table 1 for the corresponding parameters result from a considerable number of independent measurements, i.e. from at least 30 measurements.

Moreover, another commercially available suture with barbs (i.e., a Quill Monoderm knotless tissue closure device) is also provided for making such measurements. Quill^TM Monoderm^TMBi-directional barbed sutures are fabricated from monofilament fibers via a micro-machining process to cut the barbs into the suture in a helical configuration around the circumference. The barbs are separated from each other by a measured length of 0.62 to 1.39 mm, resulting in anchoring of the tissue at approximately 1 mm intervals (see table 2 below).

Inventive surgical sutures and barbed commercial sutures (Quill) tested to evaluate anchorage force^TM Monoderm^TMKnotless tissue closure devices) are characterized by a length of 15 cm.

The number of anchoring elements per mm is shown in table 2 below:

TABLE 2

The comparative measurement of the anchoring force is performed as follows.

The corresponding surgical suture is passed through a fleece textile (woolen textile) which is initially folded once and then the surgical suture is poked through the compact part of the textile using a straight needle. The textile is then unfolded, resulting in a flat textile enclosing about 2 cm of surgical suture, wherein the corresponding anchoring elements are arranged unidirectionally within the body of the fleece.

After the respective suture thread is fixed, the pull-out force is measured in the respective device (i.e. a load cell equipped with a load cell adapted to the respective force level). The force required to pull the suture out opposite the direction the barbs are pointing is measured until failure occurs or until the suture slips through the fleece textile.

The results of the corresponding measured values are shown in table 3.

TABLE 3

In table 3, the model numbers are as follows:

-USP: united states pharmacopoeia

-n: number of measurements

-x: force (in newtons, with mean (ave) and minimum (min) and maximum (max) values)

-St. dev.: standard deviation of

Table 3 shows that the inventive surgical suture has a substantially higher anchoring strength than another commercially available barbed suture. Depending on the size of the inventive surgical suture, the anchoring strength is between about 3 to about 5 times greater than that of a commercially available barbed suture having the same USP size.

Drawings

The attached drawings show that:

FIG. 1 is a schematic cross-sectional view of an inventive device (i.e., an inventive surgical suture) according to the present invention,

figure 2 is a further schematic cross-sectional view of the inventive surgical suture,

figure 3 is a further schematic perspective view of the inventive surgical suture,

figure 4 is a schematic cross-sectional view of an inventive surgical suture inserted into and in contact with tissue,

fig. 5 is a schematic view of an inventive surgical suture in which the anchoring elements (including the surgical needle and the retaining element) of the inventive surgical suture are of a unidirectional configuration.

FIG. 6 is a schematic view of the functionality of the stop element shown in FIG. 5, an

Fig. 7 is a measured holding strength value for the inventive surgical suture having the stop elements shown in fig. 5 and 6.

Detailed Description

According to fig. 1, an inventive wound closure device (i.e. an inventive surgical suture 1) comprises an elongated body 2 and a projection protruding from the elongated body 2, wherein the projection has the shape of a fin-shaped angular anchoring element 3, 3'.

The elongate body 2 and the anchor elements 3, 3' are made of the same material (i.e., a material useful for surgical sutures, e.g., a resorbable polymer, a non-resorbable polymer, or a partially resorbable polymer).

The anchoring elements 3, 3' are arranged one after the other in the same orientation in the longitudinal direction along the length of the elongated body 2 in two rows 6, 7, wherein said rows 6, 7 have a rotational offset of 180 ° from each other with respect to the longitudinal axis of the elongated body 2.

Furthermore, according to fig. 1, each of said anchor elements 3 in a row 6 is aligned with respect to each corresponding anchor element 3' of the other row 7. Thus, the distance G between any two anchoring elements 3, 3' in the rows 6, 7 is constant.

Each of said anchoring elements 3, 3' of the surgical suture 1 has an upper top portion 5, 5', a height H and a lower base portion 4, 4' having a base length L.

It can already be seen from fig. 1 that each anchoring element 3, 3' is angular and has a fin-like shape similar to the shape of a vertical fin or vertical stabilizer of a tail unit of an aircraft. This fin-like angular shape of the anchoring elements 3, 3' provided in the inventive surgical suture is an important feature for the excellent anchoring function of the inventive surgical suture.

As further shown in fig. 1, the elongated body 2 is characterized by a diameter D of its cross-sectional area. This feature will be explained in more detail in the context of fig. 2.

Furthermore, according to fig. 1, the elongated body 2 is characterized by the fact that: each section 8 of the elongated body 2 between any two consecutive anchor elements 3 of a row 6 (which are aligned with the corresponding anchor elements 3' of the other row 7) has the same tapered shape along the longitudinal direction of the elongated body 2. The tapered shape comprises a smooth change or a substantially smooth change in the cross-sectional area of the elongated body 2. The smaller (top) area of each segment 8 is oriented to the left of fig. 1 (i.e., to the direction in which the suture 1 will be inserted into tissue).

In other words: the inventive surgical suture 1 shown in fig. 1 may also be defined by a number of segments 8 having the same shape tapering in the longitudinal direction being put together, wherein between each two corresponding segments a corresponding anchoring element 3, 3' is provided in the middle.

In fig. 2, some features and parameters that have been shown and explained in relation to fig. 1 are shown and explained in more detail.

Again, an inventive surgical suture 1 having an elongated body 2 and a flipper-angle shaped anchoring element 3, 3' is shown. In this context, fig. 2 shows only two anchoring elements 3 and 3' of each of two rows rotationally offset from each other with respect to the longitudinal axis of the elongated body 2.

Each anchoring element 3, 3' has a lower base portion 4, 4' having a base length L, an upper top portion 5, 5', and a height H. As already shown in fig. 1, all anchoring elements 3, 3' have the same fin-shaped angular shape with the same height H. In this context, the height H is defined via a virtual plane on the elongated body and via the upper limit (top) of the corresponding anchoring element.

Moreover, each anchoring element 3, 3' has an inclination angle β between an imaginary plane defined on the elongated body (see definition of height H) and a corresponding (internal) plane defined by the corresponding limit of the anchoring element (see fig. 2).

Each anchoring element 3, 3 'has a lower base portion 4, 4' with substantially the same base length L. As already discussed, a key feature of the present invention is that each anchoring element 3 in a row 6 is aligned with respect to each corresponding anchoring element 3' of the (any other) row 7. In this context, due to the production of the inventive device, (very) small deviations in the position of the corresponding anchoring elements may be unavoidable. Thus, as explained previously, the following term "alignment" may be defined: there must be an overlap at least over the base length L of any two anchoring elements 3, 3' (opposite to each other). In this context, the base length L should be defined as shown in fig. 1, i.e. the distance between the two planes defined by the two outer limits of the anchoring element.

Furthermore, as is also shown in fig. 2, each anchor element 3, 3 'has a sharp edge 9, the sharp edge 9 being the front line of the anchor element 3, 3' when the surgical suture 1 is anchored in tissue. At the location of this sharp edge 9, a top angle α is defined (see fig. 2).

As already explained in the context of fig. 1, the diameter D is a characterizing feature of the elongated body 2 in the surgical suture 1, as also shown in fig. 2. As shown in fig. 2, the diameter D is chosen to be the diameter of the smallest cross-sectional area of the tapered section of the elongated body between two consecutive anchoring elements. In this context, the diameter D is the (minimum) distance between two (opposite) points of the (minimum) cross-sectional area on a virtual plane perpendicular to the longitudinal direction of the elongated body.

Also shown in fig. 2 is an (outer) diameter D0 defined by the diameter D and the height H of two aligned anchor elements. As according to fig. 2, all anchor elements 3, 3' have the same height, D0= D + 2H.

As an example, the diameter D1 (the diameter of any portion of the suture without any anchoring element present) and DN (needle diameter) are further shown in fig. 2.

In order to further clarify the explanation with reference to fig. 1 and 2, the function of the surgical suture 1 is explained as follows. The surgical suture 1 with the elongated body 2 and the anchor elements 3, 3' is inserted into the tissue and pulled through the tissue in the same direction as indicated by the anchor elements therein. This is done by a sharp end or surgical needle (not shown) attached to the left end of the surgical suture 1 in fig. 1 and 2. The anchoring elements 3, 3' will anchor themselves in the tissue surrounding the suture 1. Due to the flipper angular shape of the anchoring element, and due to the tapered shape of the section of the elongated body, there is an excellent anchoring effect of the inventive surgical suture 1.

Fig. 3 is a (further) perspective view of the inventive surgical suture 1 already shown in fig. 1 and 2. Fig. 3 is primarily intended to illustrate the design of the upper top portion 5 of the inventive surgical suture 1.

Furthermore, according to fig. 3, the following surgical suture 1 is shown: wherein the anchoring elements 3, 3' are arranged in the same orientation in two rows one after the other in the longitudinal direction along the length of the elongated body 2, wherein the two rows have a rotational offset of 180 °.

Furthermore, as is also shown in fig. 2 and marked in fig. 3 with respect to the anchor elements 3, each anchor element has a sharp edge 9, the sharp edge 9 being the front line of the anchor element when the surgical suture 1 is anchored in tissue. This will be explained further later in the context of fig. 4.

It can also be clearly seen from fig. 3 (as explained previously in the description) that the anchoring element 3 (and all other anchoring elements) has an arched shape at its upper top portion 5. Thus, as also shown in fig. 3, there is provided a crowned sharp edge on each anchoring element, which extends along the upper top portion 5 of each anchoring element. As also explained in the context of fig. 4, this arched sharp edge significantly improves the anchoring strength of the inventive suture in biological tissue.

Fig. 4 shows the following situation: wherein a surgical suture 1 according to the invention is inserted and anchored into a tissue 11.

As shown and explained in fig. 1 and 2, the suture 1 with the elongated body 2 and the anchoring elements 3, 3' is inserted by means of a sharp end or a surgical needle (not shown) attached to the left end of the surgical suture 1 and pulled through the tissue 11 into the left direction of fig. 4. As the suture 1 is inserted and passed into the tissue 11, a channel 12 is formed in the tissue.

It is noted that the passage of the suture 1 in the tissue 11 is hindered in the direction of the right part of fig. 4 (i.e. in the opposite direction to that indicated with the anchor element) because the anchor element will remain in contact with the suture 1 surrounding the tissue in the passage 12.

In this context, fig. 4 shows that the angular fin-shaped anchoring elements 3, 3' have a relatively large contact area between the upper top portion of the anchoring element and the tissue. The sharp edges, which are preferably provided in the front position during the anchoring process, also contribute to an excellent anchoring effect.

In contrast, in most existing commercial barbed sutures, the weak barb morphology causes the barbs to bend back under stress, thereby significantly reducing their anchoring ability.

Furthermore, mathematical simulation studies have demonstrated that the special features of the inventive suture, explained above, cause an anchoring behavior independent of the tissue stiffness. In this sense, the device does not require critical tissue stiffness to function properly, and thus has low sensitivity to this parameter. Simulation studies have also shown, however, that this parameter is critical in most of the existing commercial barbed sutures that require tissue stiffness to generate anchoring force. Thus, although conventional barbed sutures require barb geometry optimization, in order to achieve optimal anchoring performance in a determined biological tissue, the subject self-anchoring wound closure devices of the present invention will still exhibit optimal anchoring behavior regardless of the characteristics of the biological tissue.

Referring now to fig. 5, a schematic view illustrates an inventive surgical suture wherein the anchoring elements of the surgical suture comprise a surgical needle and a stop element are of a unidirectional configuration.

Fig. 5 illustrates in a schematic view an exemplary embodiment of a unidirectional surgical suture according to the present invention. The surgical suture 21 comprises an elongated body 22, wherein the inventive anchoring elements 23 and 23' (having their fin-shaped design) are only schematically illustrated. The anchoring elements 23 and 23 'are arranged in two rows in which all anchoring elements 23, 23' have the same height H and the same distance G (not explicitly shown). All anchoring elements 23, 23' point in the same longitudinal direction. The inventive surgical suture 21 is provided at its proximal end with a surgical needle 24 (as an example for any other possible insertion means) and comprises at its distal end a stop element 25 having a flat tab-like configuration. The stop element 25 may be formed by any suitable method known to those skilled in the art, however, preferably is formed according to the method illustrated in example 2.

The flat tab-like stop element 25 may have dimensions as outlined previously in the description. Preferably, the stop element in the form of a rectangular tab with rounded edges has a length (larger dimension) of 3.0 mm and a width of 1.5 mm. The thickness of the tab is preferably 0.15 mm.

In the context of the description of surgical suture 21 in fig. 5, fig. 6 illustrates a preferred arrangement and function of stop element 25 on surgical suture 21. According to fig. 6, the stop element 25 can have two positions. In its initial position, the stop element 25 (fixing tab) is arranged on a plane parallel to the elongated body 22 of the surgical suture 21. As the surgical suture 21 is passed through tissue and the stop element 25 is in contact with the tissue, the stop element 25 is deployed in a plane perpendicular to the elongated body 22 of the surgical suture 21. This is a result of the resistance applied to the tissue. Thus, as shown in fig. 6, after suture 21 has been anchored in tissue via anchoring elements 23, 23' provided on elongate body 22 of surgical suture 21, the second position of stop element 25 after deployment further secures the position of surgical suture 21 in tissue.

Test results have shown that the holding strength of the stop element 25 as illustrated in fig. 5 and 6 is at least equal or even statistically greater than the tensile strength requirement of a synthetic absorbable monofilament (unbarbed) suture of the same USP size.

In the latter context reference is made to fig. 7, in which the holding strength (in newton N) of the stop element 25 is shown for various sizes of the inventive wound closure device. For comparison, the USP requirements for tensile strength in newton N of the drawknot of a synthetic absorbable monofilament surgical suture (without any anchoring element) are also plotted as dotted lines in fig. 7. The corresponding value for the USP size of 2/0 is 26.3N, the corresponding value for the USP size of 3/0 is 17.4N, and the corresponding value for the USP size of 4/0 is 9.32N.

As clearly shown in fig. 7, the retention strength of the stop elements of all inventive wound closure devices having corresponding sizes are at least as high as the USP kink tensile strength (e.g., size 2/0) or even substantially higher (e.g., for size 3/0 and size 4/0).